Experimental Biology and Medicine

The effect of truncal vagotomy on the lower esophageal sphincter pressure and the response to cholinergic stimulation have been studied in humans as well as an animal model, the cat. Vagotomy was found to result in enhanced responsiveness to cholinergic stimulation. However, basal sphincter pressure was unchanged. These observations suggest that cholinergic mechanisms do not have a major effect in maintaining basal LES tone.

A seasonal covariation in calci-tonin and serotonin content of bat thyroid has been found. Whereas the mean level of thyroidal calcitonin in active bats ranged between 30 and 48 MRC mU/mg of protein, a two- to threefold increase in this level was observed prior to and during early hibernation. Associated with this increase, a relative hypocalcemia was observed. In late hibernation, thyroidal calcitonin level returned to the range observed in active bats. A parallel seasonal profile was found for bat thyroid serotonin content, which varied from a mean of 4.1 μg/g during the active phase of the annual life cycle to a peak close to 13 μg/g observed in early hibernation. The seasonal covariation of calcitonin and serotonin reflects ultrastructural changes observed in the secretory granules of thyroid parafollicular cells during the annual life cycle of the bat.

The authors wish to acknowledge the competent technical assistance rendered by Mary Ann Viloria and John Patrikes.

This work was supported in part by USPHS Grant No. AM11431 and by a grant from Ciba-Geigy Corporation, Summit, New Jersey.

Evidence for infection of male and female guinea pigs by the chlamydial agent of guinea pig inclusion conjunctivitis (Gp-ic) following intrarectal inoculation was documented by recovery of the agent from rectal swabs up to Day 23 and from segments of intestinal tract to Day 17. Anti-body response to Gp-ic was demonstrated in the serum by Day 21 although titers were low as detected by indirect immunofluores-cence. In a few instances scrapings of intestinal tissue were found to contain cells with Gp-ic inclusions when stained with Giemsa. Gp-ic inclusions were also observed in ocular smears from males and females (8 positive/35 tested) as well as vaginal smears (2 positive/16 tested). These studies augment the value of this animal model system for the study of genital infections caused by Chlamydia.

This paper is devoted to our friend Doctor Felix Milgrom of the State University of New York at Buffalo on the occasion of the thirtieth anniversary of his research activities.

The addition of promethazine hydrochloride to a suspension of rabbit alveolar macrophages in vitro results in an inhibition of cellular glucose oxidation under both resting and phagocytizing conditions as well as in an inhibition of phagocytosis of radiolabeled bacteria. The in vivo injection of the compound into rabbits partially suppresses the BCG-induced activation of the alveolar macrophages. These results suggest that the mechanism of action of promethazine hydrochloride in ameliorating the effects of erythroblastosis might lie, at least in part, in its ability to suppress the fetal macrophages which are responsible for red cell lysis.

Young pigs were rendered copper deficient as demonstrated by serum copper levels and aortic tensile properties. Tail tendons of the same pigs had normal ultimate tensile strength, elastic modulus, elastic recoil, and stress-relaxation compared to controls. These results suggest that lysine-derived cross-links of insoluble collagen of tendon may not be decreased in copper deficiency, as are the analogous elastin cross-links, or that such cross-linkages may not be the limiting factor in determining tensile strength of collagen, as they appear to be in elastin.

To examine possible relationships among purine enzyme patterns in hy-peruricemia and gout, purine enzyme activities were measured in erythrocytes from young adults who were either normouricemic, hyperuricemic, or had a family history of gout. The purine enzymes whose activities were measured included adenine phospho-ribosyltransferase (APRT), hypoxanthine phosphoribosyltransferase (HPRT), adeno-sine deaminase (AD), adenosine kinase (AK), and 5'-nucleotidase. AD and AK activities were not different among the normouricemic, hyperuricemic, or family history of gout groups. The activity of APRT was significantly higher in the group with a family history of gout compared with the normouricemics, and the activity of HPRT was significantly lower in the hyperuricemic and family history of gout groups compared with the normouricemics. The ratio of APRT/HPRT was significantly greater in 66% of those subjects who had a family history of gout and were also hyperuricemic compared with normouricemics without a family history of gout. No measurable 5'-nucleotidase was found in human erythro-cyte hemolysates. The lack of correlation between the activities of AD and AK in erythrocytes and plasma uric acid levels may be due to the lack of 5'-nucleotidase in this tissue since in the absence of 5'-nucleo-tidase the erythrocyte has a minimal capacity to break down nucleotides.

These studies were supported by Grant No. AM-16726 from the U.S. Public Health Service. Special thanks are expressed to Antone F. Salel, M.D., Department of Internal Medicine, Section of Cardiovascular Medicine, University of California, Davis, Medical School, for his cooperation in providing blood samples, and to Randy H. Shaffer for his valuable technical assistance.

Doses of SO which did not cause lymphocyte lysis or reduced viability (≤2 HU), decreased E-rosette formation. SO, treated with agents which block hemo-lytic activity (heat, oxygen, cholesterol, and anti-SO serum), did not affect E-rosette formation. Cholesterol and anti-SO serum were not able to reverse the E-rosette-in-hibiting action of SO. EAC-rosettes were not affected by SO.

Bradykinin stimulates incorporation of [¹⁴C]leucine, [³H]uridine, and [³H]thymidine into cultured lymphocytes of rat lymph nodes. Increase in [¹⁴C]leucine and [³H]uridine incorporation precedes that of [³H]thymidine.

This paper was supported by Research Grant No. 147/11 from Committee of Biochemistry and Biophysics, Polish Academy of Science.

Hemicholinium in conscious dogs with gastric fistulae and Heidenhain pouches depressed PG and 2 deoxy-D-glu-cose stimulation of acid and pepsin secretion. On the other hand, it either augmented or did not significantly change histamine- and pilocarpine-promoted secretion. These results support the view that acetyl-choline is an obligatory mediator of the action of PG at secretory effector sites.

It has been demonstrated that iron supplementation can completely prevent the anemia observed in 15-day-old mice raised on a low or high fluoride experimental diet. A higher fluoride intake was again shown to reduce the severity of the anemia seen in low fluoride animals. An increased fluoride intake has been shown to improve iron metabolism when animals were fed an experimental diet marginally adequate in its iron content. The young animals of the high fluoride group were found to have a higher total body iron content at 15 days of age than similar animals of the low fluoride group, although there was no appreciable difference in the iron content of the newborn. The higher fluoride intake of the dam also was shown to increase the iron content of the milk produced by the lactating dams, and the difference in concentration in the milk from animals in the two groups may account for the observation that there is a higher total body iron burden at 15 days of age in the high fluoride group. In older animals (15-23 days old), the higher fluoride intake was demonstrated to increase the absorption and/or retention of iron by the young mouse provided the experimental diet.

LEM obtained from glycogen-induced peritoneal exudates in rabbits were injected into the lateral cerebral ventricle of rats to determine if LEM had a primary site of action in the central nervous system. LEM injected icv in the dose of 10, 20, or 50 μl was observed to produce a rapid hy-perthermia. Injection of heated LEM failed to cause a hyperthermic response. Endo-toxin and heated endotoxin (20 ng/20 μl/ rat) administered icv each produced a delayed hyperthermia as compared to LEM. The various doses of LEM were also observed to significantly decrease plasma iron and zinc, increase plasma copper, increase the synthesis of plasma α₂ acute-phase protein (α₂-MFP), and cause a flux of a nonme-tabolizable amino acid ([¹⁴C]AIB) to the liver. These observations suggest that LEM in doses which are inactive systemically can mediate certain effects on or through the central nervous system following icv administration.

The authors wish to acknowledge the invaluable technical assistance of Ms. Beverly A. Carter and Mr. Wayne Rill. We are grateful to Drs. Philip Sobocinski and David T. George for their thoughtful discussion.

Platelet size, platelet count, and thrombopoietin levels in plasma fractions were determined in cyclic hemato-poietic (CH) dogs. Results show that platelet sizes varied inversely with platelet counts of CH dogs; significantly elevated levels of thrombopoietin were found in fractions of plasma from CH dogs at the beginning of active thrombopoiesis. These dogs serve as a useful model for studying cycling thrombopoiesis in man.

The authors thank Janet Jolly, Marilyn Cottrell, and Bill Wolfenbarger for technical assistance, Patricia Wayne for art and stenographic aid, and Dr. T. T. Odell, Jr., for helpful suggestions.

Erythrocyte adenosine triphos-phate (ATP) concentration was found to increase in adult rhesus monkeys which have been injected with 3.5 mg of epinephrine. The average increase in red cell ATP concentration was 19.5% (significant at the 1% probability level). Epinephrine injection also increased the concentration of the early red cell glycolytic intermediates, glucose 6-phosphate (G6P), fructose 6-phos-phate (F6P), and dihydroxyacetone phosphate (DHAP). Respiratory alkalosis, which might have been induced by the epinephrine, is not responsible for the glycolytic changes. This effect of epinephrine on rhesus red cell glycolysis is compatible with an in vivo stimulation of red cell hexokinase by epinephrine or some substance elicited by epinephrine and suggests the possibility that such a stimulation may have a physiologic role in the mammalian erythrocyte.

The authors wish to thank John A. Faulkner and Daniel H. Ringler for their help in the experiments involving the injection of monkeys with epinephrine. This work was supported in part by the Research and Development Command, Department of the Army and Navy, under Contract No. DADA17-69-C-9103, and in part by the National Institutes of Health Training Grant No. 5T01-GM-0071.

Purified group A and C me-ningococcal polysaccharide vaccines prepared in these laboratories caused remarkably little local or systemic reaction and were highly effective in stimulating serum bactericidal antibody in studies carried out in adults. There was no measurable reduction in immunogenicity or increase in toxic reaction when the two vaccines were given in combined form in a single dose. Maximal antibody response was obtained following a single dose of vaccine and there was no increase in titer when additional doses were given 1 and 6 months later. Both vaccines retained their immunogenic potency on storage at 4° for at least 1 year and there was no reduction in immunogenicity on storage for up to 2 weeks at 4° following rehydration in thimerosal preservative solution.

The authors are greatly indebted to Joan Goshow and Joan Staub for valuable technical assistance. We wish also to acknowledge the medical assistance of Drs. Frank D. Gray, George A. Starkweather, and W. Stuart Warren, and the nursing assistance of Janet Campbell, Karen Campbell, and Jane Laughead. The administrators and personnel of the Haverford Township Schools are cited for their helpful cooperation.

All of 20 children sampled who had received Enders' original measles vaccine, together with human immune globulin, retained measles antibody for 15 years with essentially no decline in antibody titer. All but one of 24 children who received Enders' original measles vaccine and all of 33 children who received more attenuated measles virus vaccine (Moraten line, Atte-nuvax) retained their antibody for 8 years, the longest time period tested. These data support the concept that the problems with efficacy of measles virus vaccine are more related to handling and administration of the vaccine itself than with the attributes of the vaccine.

The authors are indebted to Elizabeth D. Posner for statistical computations and to Robert R. Roehm, Susan A. Brown, Monica E. Hoover, and Helene M. Eliff for technical services. Karen Campbell provided valuable nursing assistance.

A system is described which permits rat lenses to be cultured and studied for periods in excess of 3 weeks without loss of transparency or an increase in size. When galactose is added to the medium, the lenses undergo morphological changes comparable with those found in vivo with the eventual production of nuclear cataracts. Lenses cultured with the ciliary body attached are less likely to be injured during dissection and can be cultured as effectively as isolated lenses.

Aged A/J mice, an autoimmune strain, develop increasing levels of serum IgA compared to aged DBA/1J mice, a nonautoimmune strain.

Adult thymectomy did not affect IgA levels in A/J and DBA/1J mice but accelerated anti-DNP antibody formation in A/J mice. These results can be explained by spontaneous loss of suppressor T cells which prevent the formation of anti-DNP antibodies in A/J mice.

Experiments involving thymectomized, irradiated mice reconstituted with irradiated thymus and bone marrow from donors of varying ages suggested that there are intrinsic changes and thymic epithelium function with age. Bone marrow cells from aged donors were not as effective in restoring IgA levels and suppressing anti-DNP antibody as those from young donors.

Thymic epithelium from aged donors was not as effective as that from young donors in suppressing the formation of anti-DNP antibodies.

The authors express their appreciation to Mrs. Jane Lyons, Tom Cable, and Mrs. Peggy Cook for technical assistance; to Mrs. Mona Myers and Ms. Wendy Pitt-man for typing and preparation of the tables; and to Dr. Bryan Gebhardt for a critical review of the manuscript.

The effects ot two β-adrener-gic receptor-blocking agents, timolol and propranolol, on resting PRA and on the hydralazine-induced increase in PRA were studied in SHR and in two strains of normo-tensive rats [Wistar (NWR) and Sprague-Dawley (NSDR)]. With single oral doses, these β-adrenergic-blocking drugs reduced PRA in a dose-dependent manner in SHR but not in NWR or NSDR. After four daily doses, timolol antagonized the hydralazine-induced increase in PRA in SHR and lowered PRA in NWR. Timolol lowered PRA in NSDR only at 10 mg/kg/day p.o. for 4 days. It was concluded that SHR are more sensitive than normotensive rats to the PRA-lowering effects of β-adrenergic-blocking drugs.

The tracer [4-¹⁴C]cholesterol, incubated at 37° for 1 hr with the subject's own plasma, was administered intravenously to two subjects. The initial rapid decrease of plasma cholesterol specific activity indicated a net disappearance of [4-¹⁴C]cholesterol from the bloodstream, presumably due to phagocytosis of the particu-late cholesterol by the reticuloendothelial system. The initially disappeared [4-¹⁴C]cholesterol quickly reappeared in the blood. Complete equilibrium between RBC and plasma-free cholesterol was attained within 12-18 hr, whereas the equilibrium between plasma-free and esterified cholesterol required 2 days. Therefore, the com-partmental analysis should be based on the plasma total cholesterol specific activity obtained 2 days after the injection.

Genetically obese mice initially gained less body weight when fed diets containing fructose in comparison to mice fed starch, sucrose, or glucose diets. Plasma glucose concentrations were significantly lowered by fructose diets in both obese and nonobese mice in comparison to starch and glucose but not sucrose diets. Fructose or sucrose feeding did not induce hypertriglyc-eridemia in obese or nonobese mice as has been shown in the rat. In fact, the fructose diet significantly lowered plasma triglycer-ide concentrations in nonobese mice.

The authors express their appreciation to Rosemary Carr and Olden Green for expert technical assistance provided for this study. This research was supported by USPHS Research Grants Nos. AM 00106 and AM 02911, a grant from the Finn-Cal Sweetener Company, San Francisco, and the Fund for Research and Teaching, Department of Nutrition, Harvard School of Public Health.

It is important for the purpose of obtaining PP₁ase activity to promptly harvest 5. mutans KlR cells at the height of the log phase of growth or an OD of 0.5 at 660 nm. The apparatus shown in Fig. 1 enables one to grow streptococcal cells and to determine specifically during the growth cycle when to harvest the cells. Of the five cell disruption techniques tried, ultrasonic treatment is obviously the technique of choice for disruption of S. mutatis KlR cells and solubilization of PP_iase for maximum yield.

FSH treatment of hypophysec-tomized immature rats increased testicular weight, increased the number of LH receptors per testis, and increased the in vitro testicular testosterone production in response to LH. The increase observed in all three parameters was related to the duration of FSH treatment. The testicular response to LH was enhanced to a greater extent than the number of LH receptors. The specificity of the FSH effect was indicated by the observation that administration of LH had no effect on testicular weight or number of LH receptors. LH administration did not increase the in vitro testicular response to LH, but appeared to prevent the decrease in this response observed in saline-injected controls.

We thank Carol Craig for expert technical assistance. We also thank Dr. A. F. Parlow for the rat LH, NIAMDD-Rat LH-I-3, and NIAMDD for supplying the NIH-FSH-S11 and NIH-LH-S19. This study was supported by NIH Grant No. HD-08358.

The adipocyte size frequency distributions were determined during the preobese and obese phases of development in ob/ob and non-ob/ob mice. Only the small- and moderate-sized cells were evaluated. A procedure was presented that transformed composite data from the population distributions of individual samples into a form suitable for comparisons by chi-square. Among the obese animals, the frequency of small cells continued to increase during development, which resulted in a bi-modal distribution after 10 weeks of age. During the preobese phase of development at Week 3, the adipocyte size frequency distribution of the ob/ob mice was significantly different from that of non-ob/ob animals. Discriminant analysis suggested that adipocyte size frequency distributions may be used to identify ob/ob animals during the preobese phase of development.

Chlorothiazide in the incubating medium significantly reduces net glucose utilization, glycogen content, and net lactate production of normal dog aorta. When no glucose is present in the incubating medium, these actions of chlorothiazide are not evident. When 1.2 mM lactic acid is present in place of glucose as substrate, net lactic acid production of aorta is decreased by chlorothiazide and glycogen content is unaltered.

Human fibroblast interferon has been shown to bind to blue dextran with binding that is reversible on the addition of 3 M KC1. Attachment of human fibroblast interferon to blue dextran and subsequent release results in a 3.5-fold purification with 50% recovery.

This investigation was supported, in part, by Grant No. 05-041-012 of the National Aeronautics and Space Administration, and by Public Health Service Grant No. T)1-AI 00466 from the National Institutes of Health.

In 65% of constant estrous an-ovulatory (CEA) rats bearing a frontal hy-pothalamic deafferentation (FHD), ovulation reappears after pinealectomy or bilateral superior cervical ganglionectomy. In nearly 50% of the FHD rats which ovulated after pinealectomy or ganglionectomy, serum LH showed an elevation on the day of “vaginal proestrus.” In the remaining 50% of the animals, ovulation occurred without observable variations in serum LH concentrations. The LH peak was probably missed in these animals because insufficient numbers of blood samples were collected. The data suggest that pinealectomy and cervical sympathectomy may induce LH release. It is proposed that this occurs through an interference with the hypothalamic and brain stem serotoninergic system which normally keeps LH under an inhibitory tone.

To study the role of immuno-logic reactions in the development of alcoholic liver disease, cytotoxic activity of lymphocytes against autologous liver grown in tissue culture was investigated. The experimental model was that of ethanol-fed baboons which develop the entire spectrum of alcoholic liver disease. Liver tissue was obtained at laparatomy in 12 animals given alcohol for 16-38 months and in 12 pair-fed controls. Lymphocytes of all alcohol-treated animals (but not of the controls) exhibited cytotoxicity against autochthonous liver cells: there was a marked decrease in the number of surviving cells and a significant reduction in their [³H]proline label.

We thank C. Pereira and L. M. DeCarli for their expert assistance.

Highly purified canine prolactin has been prepared and partially characterized. The material is comparable in potency to ovine prolactin, and similar in amino acid composition as well.

I thank Prof. C. H. Li for reading the manuscript and his suggestions. I also thank Dr. M. Aubert, Dr. S. W. Farmer, Jean Knorr, and J. D. Nelson for their assistance. The canine pituitaries were put at my disposal by Dr. S. Kaplan (Dept. of Pediatrics) and Dr. R. Weiner (Dept. of Obstetrics and Gynecology), both of the University of California, San Francisco. This work was supported in part by a grant from the National Institutes of Health (AM-6097) and a Rockefeller Center Grant.

Cytochalasin B, colchicine, and vinblastine decrease the antiviral effect of interferon when added to cells simultaneously with interferon. The drugs are effective alone but their potency increases when used in combination. The lack of development of the antiviral state is observed without any detectable modifications in cellular RNA or protein synthesis. These drugs are known to disrupt microtubules and microfil-aments which are therefore probably necessary for interferon action. They could be involved in the distribution of membrane-associated receptors and/or in interactions between receptors and the cytoplasma. The initial steps leading to the establishment of antiviral protection by interferon could depend on these mechanisms.

We thank Isabelle Tardivel for technical assistance and Carol Girard for help with the manuscript. Partial support came from the Delegation Generate a la Recherche Scientifique et Technique (Contract No. 74.7.0576).

We have studied the sequential changes of cholesterol content and morphology in RBC of cholesterol-fed GP and the effects of these changes on their energy metabolism and osmotic fragility. The results suggest that (i) spurring of GP RBC is not accompanied by obvious alterations in their energy metabolism and may be the end result of sequential shape transformations associated with cholesterol-loading, and (ii) neither the morphological abnormalities nor the decreased osmotic fragility of cholesterol-loaded RBC is directly related to the development of the hemolytic anemia.

Our thanks go to Dr. T. Hayes, Donner Laboratory, University of California, Berkeley, for the scanning electronmicrograph and for permission to publish it. The replicate experiment (Table I, Expt. 2) was carried out by Jacqueline Fields.

A method of aging cells is described which allows for an increase in sensitivity of the assay of interferon. After reaching confluency the cell cultures are aged at 30° for 5 days, the growth medium is replenished, and the cells are incubated for an additional 24 hr at 37° before applying interferon. Using cell cultures so treated (dip-loid cells HFS-1 or HR-203), and mouse L-929 cells), the sensitivity of the interferon assay increase from 16- to 30-fold for human and up to 10-fold for mouse standard interferon.

We are grateful to J. A. Green, C. E. Buckler, and S. Baron for helpful advice.

To study the role of excess corticosterone on regulating puberty onset without the added component of a stressful route of administration, corticosterone was made available ad libitum in the drinking water beginning at weaning age (22 days of age). The lowest dose (16 μg of corticoster-one/ml of 4% ethanol in tap water) did not delay puberty but did suppress the normal peak of corticosterone at 1600 hr. The next dose (24 μg) also suppressed the evening corticosterone peak. In these rats, vaginal opening was normal but ovulation was delayed in comparison to controls given 4% ethanol in tap water or tap water alone. Growth rates in the rats given 16 or 24 μg were normal. The two high concentrations (160 and 240 μg of corticosterone/ml 4% ethanol of in tap water) delayed both vaginal opening and ovulation, produced high levels of corticosterone in the blood at 0800 and 2300 hr and a depression of corticoster-one at 1600 hr, and were associated with significant growth retardation. It is concluded that a normal adrenal rhythm is not required for puberty onset and that the ability of exogenous corticosterone to delay puberty onset can be mediated through routes other than growth retardation alone.

This work was supported by NSF Grant No. 74-21733. Mary Alyce Vornholt and Tim Grinbergs provided expert technical help.

The thyroidal content of CT was measured by bioassay and radioimmu-noassay in intact, parathyroidectomized, and adrenalectomized rats fed diets with varying Ca:P ratios for 4 to 8 weeks. There was a good correlation between values obtained with the two assay methods. In intact, parex, and adrex rats, thyroidal CT content was higher 4 and 8 weeks after feeding a diet with a Ca:P ratio of 1:8. However, there was a little difference in overall CT content between intact, parex, and adrex rats despite marked differences in the levels of serum calcium. CT content appeared to be related to the length of time the rats were fed the high phosphate diet. In intact rats fed diets with Ca:P ratios ranging from 8:1 to 1:8 and prepared by varying the calcium content (P constant at 0.4%), the CT content of thyroid gland and serum was elevated only in those animals fed the 1:8 diet. In other intact rats fed with diets having the same range of ratios but prepared by varying the phosphorus content (Ca constant at 0.4%), thyroidal CT increased progressively with the diets having a Ca:P ratio below 1:1. The results indicate that changes in thyroidal CT stores produced by feeding diets with varying Ca:P ratios cannot be explained solely on the basis of changes in the levels of serum calcium.

In recent years, the gastrointestinal hormones gastrin and cholecystokinin-pancreo-zymin (CCK-PZ) have been looked upon as potential growth factors of the digestive tract glands. A survey on the spectrum of growth-related responses affected by these hormones shows that chronic in vivo administration of large amounts of pentagastrin produces oxyntic gland hyperplasia (1). Lichtenberger and Johnson (2) conclude from their studies on the ontogenic development of the small intestine, that some aspects are dependant on weaning and gastrin may be the mediator.

The hormonal control of pancreatic growth could be controlled by gastrin and CCK-PZ. Indeed, in hypophysectomized rats, pentagastrin treatment stimulates pancreatic hyperplasia in addition to hypertrophy (3). In normal rats, large doses of pentagastrin also result in pancreatic acinar cell hypertrophy (4).

Since CCK-PZ and gastrin share the same five C-terminal amino acids which comprise the active center of the gastrin molecule, one would thus expect the duodenal hormone to have comparable trophic effects on the pancreatic tissue. Recent data from Johnson and Guthrie (5) indicate a certain specificity of the trophic effect of CCK-PZ for the pancreatic tissue since CCK-PZ octa-peptide administration was associated with increases in DNA synthesis in the pancreas but not in the oxyntic gland or duodenum. Mainz et al. (6) established clearly that CCK-PZ administration at a dose of 20 IVY units kg, ip twice daily for 5 days, was associated with increases in cell mass and cell numbers. In similar studies, Barrowman and Mayston (7) also established the trophic effect of CCK-PZ on the exocrine pancreas.

Since the trophic effect of an hormone implies the regulation of a number of growth-related processes in the target tissue, such as stimulation of protein, RNA, and DNA synthesis, these major effects should be seen at any time during the normal growth of an animal.

Adrenal mitochondria were obtained from rats subjected to two different crowding regiments in order to test the in vitro capacity for 11 β-hydroxylation (11β-OH) as an index of stress. Compared to controls, 110 cm 2 of floor space per rat, crowding at 30 cm 2 /rat markedly increased 11β-OH. Little change occurred when rats were held at 50 cm 2 /animal. High levels of 11β-OH persisted 3 weeks after the termination of severe crowding. This apparent failure to reverse crowding stress is viewed in terms of pathologic changes that appear to accompany crowding stress. On the basis of measuring 11 β-OH capacity, it is possible to differentiate between the stressful effects of the housing conditions.

The addition of a small amount of riboflavin to an otherwise adequate diet, but a diet containing the hepatic carcinogen 3'-methyl- 4 - dimethylaminoazobenzene, strongly inhibits the carcinogenicity of the dye when fed to rats for 18 weeks. Most of the rats (80%) did not develop hepatomas. When the riboflavin antagonist 7,8-diethyl-flavin was also added to the above basic diet, all of the animals developed tumors (80%) or precancerous lesions (20%). When 7-chloro-8-methyl-flavin was added to the above basic diet, which of its two properties, the vitamin-like or the riboflavin antagonist properties, predominated depended on the quantity administered, but the flavin did not protect the livers from gross abnormalities. When the flavin 7,8-diethyl-aminol-flavin was added to the above basic diet, none of the animals developed hepatomas, suggesting that this flavin possesses strong vitamin-like properties or that it is capable of protecting the liver against the effects of the carcinogen.

Cells from three Burkitt lym-phoma lines and three normal-derived human lymphoid lines were cultured in diffusion chambers implanted into mice. Cytoge-netic analysis was made on all these cell lines following treatment of the animals with cyclophosphamide. The Burkitt lymphoma cell lines were uniformly more sensitive to cyclophosphamide than the normal-derived cell lines, having a chromosome aberration incidence of 58-82% compared to 14-23% for the latter cell lines. Studies in tissue culture failed to reveal either the cytostatic effect of cyclophosphamide or an effect on chromosomes.

Administering triamcinolone, 1 mg kg^-1 24 h^-1, results in increased ammonium excretion which resembles that observed during acid loading. This increase cannot be attributed to tubular ion exchanges or potassium depletion but, rather, is due to triamcinolone's effect upon renal ammonia production. The three- to fourfold increase in ammonia, glucose, and ¹⁴CO₂ production is consistent with glucocorticoid mediation of the mitochondrial glutaminase I activation.

I am indebted to Dr. M. Chrétien, Director of Protein and Pituitary Hormone Laboratory of the Clinical Research Institute, for reviewing this manuscript, and to the excellent secretarial assistance of Misses Carole Tremblay, Anne Lespérance, Mrs. Anne Masseau, and Linda Paquette.

The principle of complement-mediated immune adherence was applied to development of an immune adherence he-magglutination (IAHA) assay for antibody to cytomegalovirus (anti-CMV). Compared to complement fixation (CF), IAHA was two to eight times more sensitive for the detection of anti-CMV. In paired serum samples from multiply transfused patients, the concordance between rises in anti-CMV titers detected by CF and IAHA was 0.671 (P < 0.001). Convalescent titers measured by IAHA were significantly higher than those determined by CF in serum pairs in which anti-CMV rises were demonstrated by both techniques, and IAHA more commonly revealed anti-CMV in pretransfusion serum samples. No difference was noted between the kinetics of CF and IAHA antibody development after transfusion. Immune adherence hemagglutination, we conclude, is an efficient, sensitive alternative to CF for the detection of anti-CMV.

The authors thank Mrs. Virginia L. Frye for preparing the typescript, and Dr. David W. Ailing for assistance with statistical evaluation.