Antibody responses in adult volunteers to pneumococcal polysaccharide types 19F and 19A administered singly and in combination

The immunogenicity of the two major group 19 pneumococcal polysaccharides, types 19F and 19A, was studied in human volunteers. Antibody responses after vaccination with either 50 micrograms of type 19F polysaccharide, 50 micrograms of type 19A polysaccharide, or 25 micrograms of both polysaccharides premixed in a single injection revealed that the combined vaccine was immunogenic for both types, but that the optimal immunogen for each was the homologous polysaccharide. We concluded that vaccination with type 19F polysaccharide antigen, included in the current pneumococcal vaccine, does not induce a satisfactory heteroimmunogenic response to type 19A.

Immune response of neonates to pneumococcal polysaccharide-protein conjugate

Immune responses were studied in adult and young mice exposed to pneumococcal 6A and 19F polysaccharides (PSs), as well as 19F PS conjugated to proteins, e.g. human immunoglobulin G (HIgG), pneumococcal R61 cell wall polypeptide, and bovine serum albumin (BSA). Significantly higher IgM and IgG2 antibody titres were induced in mice receiving 19F PS-protein conjugates than in the control group receiving 19F PS alone. Maternal immunization with 19F PS-HIgG conjugate elicited a low immune response in the offspring. However, when young mice from immunized mothers were given and additional dose of polysaccharide-protein conjugate, they gave an antibody response greater than that of mice not given additional immunogen. Similarly, young mice exposed to 14-valent pneumococcal vaccine during gestation produced higher antibody response to 6A and 19F PSs. Secondary immunization of 19F PS or PS-protein conjugate at 1 or 2 weeks after primary immunization did not enhance antibody formation but rather suppressed the immune response to that polysaccharide.

Cross-immunogenicity of pneumococcal group 9 capsular polysaccharides in adult volunteers

Group 9 organisms (types 9N, 9A, 9L, and 9V) account for about 3 to 4% of pneumococcal disease isolates throughout the world. Types 9N and 9V comprise about 90% of the group 9 disease isolates. Type 9N is more common than type 9V in adults, and type 9V predominates in infants and children. In the United States there have been eight reported cases due to group 9 pneumococci in individuals previously vaccinated; six were type 9V and two were type 9N. To ascertain the cross-immunogenicity of group 9 polysaccharides, volunteers were injected with vaccines of monovalent types 9N, 9A, 9V, or 9L, or bivalent (9N and 9A) or trivalent (9N, 9A, and 9V) polysaccharide vaccines. Monovalent types 9N, 9V, and 9L each stimulated a 5.8- to 7.5-fold geometric mean rise, and at least 80% of the volunteers responded with a twofold or greater homologous antibody rise. Type 9V induced a 5.8-fold geometric mean rise, but only 66% of the volunteers responded with a twofold or greater homologous antibody rise. Type 9N induced only a 2.1-fold geometric increase, and only 54% of the volunteers responded with a twofold or greater rise in anti 9V antibodies. Types 9L and 9A were the most cross-immunogenic. The trivalent preparation (9N, 9A, and 9V) gave the highest geometric mean titer and seroconversion rate to each of the group 9 polysaccharides. These results suggest that the polyvalent pneumococcal vaccine with its type 9N does not induce a satisfactory anti-type 9V response and should contain additional components in order to achieve greater protection against group 9 organisms.

Immunochemical relations between pneumococcal group 19 and Klebsiella capsular polysaccharides

Pneumococcal type 19F polysaccharide, contained in the current U.S. licensed pneumococcal vaccine, is a poor immunogen in young children. Capsular polysaccharides of Klebsiella, reported to be cross-reactive with the pneumococcal type 19F, were isolated. Immunochemical relations between pneumococcal group 19 and Klebsiella capsular polysaccharides were studied by immunodiffusion with hyperimmune typing antisera, immune passive hemolysis, and plaque-forming cell response in mice following injection of polysaccharides. Klebsiella K2, K9, K32, K47, and K48 polysaccharides were reported to cross-react with horse pneumococcal type 19 antiserum by direct precipitation. However, these Klebsiella polysaccharides did not react in immunodiffusion with horse or with rabbit pneumococcal 19F and 19A typing antisera. Furthermore, pneumococcal type 19F and 19A polysaccharides did not precipitate with rabbit K2, K9, K32, K47, and K49 typing antisera. The cross-reactivity of the Klebsiella and pneumococcal polysaccharides was studied by 2 other methods. Rabbit pneumococcal 19F antiserum induced by low passive hemolysis of sheep erythrocytes coated with Klebsiella polysaccharides. In contrast, Klebsiella typing antisera exhibited higher hemolytic activity with erythrocytes coated with type 19F polysaccharides. The cross-reactivity of K2 and pneumococcal 19F polysaccharides was also exhibited by the direct IgM plaque-forming cell response. The cross-reactivity, determined by precipitin reactions using animal antisera, may not predict the cross-immunogenicity of purified polysaccharides in humans.

Immunochemical relations between pneumococcal group 19 and Klebsiella capsular polysaccharides

Pneumococcal type 19F polysaccharide, contained in the current U.S. licensed pneumococcal vaccine, is a poor immunogen in young children. Capsular polysaccharides of Klebsiella, reported to be cross-reactive with the pneumococcal type 19F, were isolated. Immunochemical relations between pneumococcal group 19 and Klebsiella capsular polysaccharides were studied by immunodiffusion with hyperimmune typing antisera, immune passive hemolysis, and plaque-forming cell response in mice following injection of polysaccharides. Klebsiella K2, K9, K32, K47, and K48 polysaccharides were reported to cross-react with horse pneumococcal type 19 antiserum by direct precipitation. However, these Klebsiella polysaccharides did not react in immunodiffusion with horse or with rabbit pneumococcal 19F and 19A typing antisera. Furthermore, pneumococcal type 19F and 19A polysaccharides did not precipitate with rabbit K2, K9, K32, K47, and K49 typing antisera. The cross-reactivity of the Klebsiella and pneumococcal polysaccharides was studied by 2 other methods. Rabbit pneumococcal 19F antiserum induced by low passive hemolysis of sheep erythrocytes coated with Klebsiella polysaccharides. In contrast, Klebsiella typing antisera exhibited higher hemolytic activity with erythrocytes coated with type 19F polysaccharides. The cross-reactivity of K2 and pneumococcal 19F polysaccharides was also exhibited by the direct IgM plaque-forming cell response. The cross-reactivity, determined by precipitin reactions using animal antisera, may not predict the cross-immunogenicity of purified polysaccharides in humans.

Effects of supplementation of the diets with calcium and calcium-rich foods on bone density of elderly females with osteoporosis

Diets of 20 elderly females with osteoporosis were supplemented daily with 2.25 oz of processed cheese, and 3 capsules of dicalcium phosphate + vitamin D containing 350 mg Ca, 270 mg P, and 399 IU vitamin D, for a 6-month period. The bone density of the 3-2 phalanx was measured densitometrically from the hand x-ray taken with a standard aluminum stepwedge. Fasting blood and urine were analyzed at the beginning and end of the experimental period. The mean bone density increased (p less than 0.05). There were 11 subjects with increased bone density, three with no changes and six with reductions in bone density. Calcium, P, and alkaline phosphatase in serum and Ca/creatinine and P/creatinine in urine were unchanged. The changes in bone density were correlated to the changes in body weight (r = 0.6529). The results suggested that, even with a mean age of 70 yr, some elderly persons can benefit from supplementary Ca and Ca-rich foods to improve bone density.

Chemical structure of and immune response to polysaccharides of Streptococcus pneumoniae

By use of rabbit antisera, extensive cross-reactions were demonstrated among pneumococcal (Danish) types 6A and 6B, types 9N, 9A, 9L, and 9V, and types 19F and 19A. The structural similarity of the group 6 polysaccharides was associated with extensive immunogenicity in humans. In contrast, immunization of humans with type 19F or 19A may not induce sufficient cross-protection. The type 19F polysaccharide has the structure of a linear polymer of N-acetylmannosamine-glucose-rhamnose phosphate. Danish type 19A (type 57 in the United States system) polysaccharide contains this repeating unit and, in addition, has side chains of N-acetylglucosamine-galactose phosphate and fucose phosphate. Maternal immunization with type 19F or type 6A polysaccharide during pregnancy elicited high antibody formation in the offspring. Young mice, which received an additional dose of polysaccharide at two weeks of age, showed a higher antibody response than did those that did not receive polysaccharide. These studies reveal that the extensive cross-immunogenicity of pneumococcal group polysaccharides has a basis in chemical structure. Maternal immunization with pneumococcal polysaccharides may enhance the immune response of neonates.

Studies on vaccine control and immunogenicity of polysaccharides of Streptococcus pneumoniae

An immunoelectrophoretic method was devised for quantitation of 14 polysaccharide components in the pneumococcal vaccine, and for determination of their stability in the final container. By this method the individual polysaccharide types, 1, 2, 3, 4, 6A, 8, 9N, 12F, 18C, 19F, 23F, and 25 (Danish nomenclature), were found to be present at 80%-123% of the manufacturer's listed concentrations. Pneumococcal polysaccharide types 3, 6A, 9N, and 19F, used as representative types, were heated at 37C for 24 hr and stored at 4 C. The concentrations of these polysaccharides remained constant over a 12-month period, and the molecular sizes of types 3 and 9N were stable during storage. In contrast, the molecular sizes of types 6A and 19F declined gradually during the 12-month storage period. Pneumococcal type 19F polysaccharide was conjugated to various proteins, i.e., bovine serum albumin, human immunoglobulin, and pneumococcal R61 cell wall protein, by the method of reductive amination. Immunization of mice with 19F polysaccharide-protein conjugates resulted in formation of more antibody than was found in the control group. Young mice exposed to pneumococcal type 19F polysaccharide-protein conjugate during gestation and suckling exhibited a greater antibody response than did mice that received no type 19F polysaccharide-protein conjugate while suckling or received the conjugate only when they were only two weeks of old.

Immunochemical characterization of cross-reactivity of pneumococcal group 9 capsular polysaccharide types 9N, 9A, 9L, and 9V

The chemical composition and immunochemical characterization of the four cross-reactive pneumococcal capsular polysaccharides within group 9 (types 9N, 9A, 9L, and 9V) were investigated. Their serological reactions were studied by using unabsorbed antisera prepared by immunizing rabbits with pneumococci of each of the four group 9 capsular polysaccharide types. Type 9A antiserum showed the most extensive cross-reactions with the four group 9 polysaccharides. Absorption with type 9N, 9L, or 9V polysaccharide removed 63, 96, or 87%, respectively, of the heterologous antibodies from the type 9A antiserum. All four of the group 9 polysaccharides contained glucose, N-acetylmannosamine, and glucuronic acid. In addition, types 9N and 9L had N-acetylglucosamine, and types 9A, 9L, and 9V contained galactose. Reduction of the uronic acid residues of the type 9 polysaccharides removed most of their homologous and much of their heterologous reactivities, indicating an important role for the uronic acid component in their antigenicity. The four group 9 polysaccharide preparations had comparable molecular sizes and only traces of protein and nucleic acid. Further studies to evaluate the most protective type among the group 9 strains to be included in the current pneumococcal vaccine are discussed.

Maternal-foetal interaction, antibody formation, and metabolic response in mice immunized with pneumococcal polysacharides

The maternal transfer of pneumococcal polysaccharides to foetus, as well as the antibody formation and metabolic response were studied in mice exposed to pneumococcal polysaccharides during pregnancy. Type 19 and type 57 pneumococcal polysaccharides display cross-placental transfer to foetus. These polysaccharides also transfer through mother's milk to neonates. Maternal immunization of type 19 polysaccharide during pregnancy induced higher antibody formation in the offspring than the group from non-immunized mothers. Young mice, which received a second dose of polysaccharide at 2 weeks of age, showed a higher antibody response than those which did not receive polysacharide. Treatment of mothers with anti-lymphocyte serum, following by administration of polysaccharide, significantly increased the neonatal immune response to the polysaccharide. Treatment of the mother with a high dose of type 19 or type 57 polysaccharide did not cause significant changes in neonatal growth and organ weights. The offspring from mothers treated with high doses of these polysaccharides did not exhibit abnormalities in chemical contents of their tissues.

The structures of the cross-reactive types 19 (19F) and 57 (19A) pneumococcal capsular polysaccharides

The structures for two cross-reactive capsular polysaccharides isolated from Streptococci pneumoniae types 19 and 57 are proposed based on the analytical data obtained from methylation, enzymatic degradation, and periodate oxidation experiments performed on both intact polysaccharides and oligosaccharides isolated from hydrofluoric acid hydrolysates. Both polysaccharides exhibit an identical structure of 4)-beta-2-acetamido-2-deoxymannose-(1 leads to 4)-alpha-D-glucose-(1 leads to 2)-alpha-L-rhamnose-1-phosphate. This trisaccharide is considered the only repeating unit in the type 19 polysaccharide. The type 57 polysaccharide contains this same repeating unit and side chains composed of a beta-D-2-acetamido-2-deoxyglucose-(1 leads to 3)-beta-D-galactose-1-phosphate side chain attached to C-2 of the glucose and an alpha-L-fucose-1-phosphate attached to C-3 of the rhamnose.

Comparative immunogenicity of group 6 pneumococcal type 6A(6) and type 6B(26) capsular polysaccharides

The comparative immunogenicity of the two cross-reacting group 6 pneumococcal capsular polysaccharides, type 6A(6) and type 6B(26), was studied with hyperimmune rabbit typing antisera and with sera from adult volunteers injected with polyvalent pneumococcal vaccines containing either 50 mug of type 6A (U.S. designation, type 6) or 50 mug each of type 6A and type 6B (U.S. designation, type 26) polysaccharides. Both group 6 polysaccharides were linear copolymers composed of 1 mol each of d-galactose, d-glucose, l-rhamnose, and d-ribitol phosphate. They differed only in that type 6A had a rhammopyranosyl-(1 --> 3)-d-ribitol bond and the type 6B had a rhamnopyranosyl-(1 --> 4)-d-ribitol bond. Quantitative precipitation and absorption analyses with rabbit hyperimmune antisera induced by simultaneous injection with type 6A and type 6B organisms revealed extensive cross-reactions between the two group 6 polysaccharides. There was less, although still quite extensive, cross-reactivity between the two group 6 polysaccharides examined with antisera from rabbits injected with only one of the group 6 pneumococci. In a radioimmunoassay, using (14)C internally labeled type 6A or type 6B polysaccharide antigens, there was no difference in the serum antibody level to either type of volunteer injected with polyvalent pneumococcal vaccines containing type 6A or both type 6A and type 6B polysaccharides. These studies indicate that the structural similarity of the pneumococcal group 6 polysaccharides confers extensive cross-reactivity with hyperimmune typing antisera prepared with whole organisms or after injection of purified polysaccharides in adult volunteers. With our current polysaccharides, it appears that a polyvalent pneumococcal vaccine formulation that contains only type 6A will serve to induce the maximum amount of serum antibodies to both group 6 organisms.

Characterization of the cross-reaction between type 19F(19) and 19A(57) pneumococcal capsular polysaccharides: compositional analysis and immunological relation determined with rabbit typing antisera

The immunological relation, physicochemical characteristics, and chemical composition of type 19F(19) and 19A(57) within the cross-reactive group 19 pneumococcal capsular polysaccharides were studied. By using rabbit hyperimmune diagnostic antisera in agglutination, immunodiffusion, quantitative precipitation, and absorption assays, extensive cross-antigenicity and cross-immunogenicity were demonstrable between the disease-associated types 19F(19) and 19A(57). Types 19B(58) and 19C(59), rarely associated with human disease, were extensively cross-reactive with each other but reacted weakly with types 19F(19) and 19A(57). Both types 19F(19) and 19A(57) polysaccharides contained trace amounts of protein and nucleic acid and had comparable molecular sizes as determined by gel filtration. Compositional analysis showed type 19F(19) to contain rhamnose, glucose, N-acetylmannosamine, and a phosphate ester. Type 19A(57) contained these four moieties, and in addition, contained fucose, galactose, and N-acetylglucosamine. Plans for using this information to evaluate current and proposed formulation of multivalent pneumococcal polysaccharide vaccines are discussed.

Nutritional status of selected teenagers in Kentucky

A nutrition survey was conducted in a six-county area of Kentucky which included 118 teenagers of both races and sexes, with a mean age of 15.5 years. Data collected included one 24-hr dietary recall, meal practices, smoking, and physical activity. Fasting blood and urine were analyzed. White boys had higher intakes in overall nutrients and had more regular meal taking habits than others. Intakes of calcium, iron, and vitamin A were grossly deficient among girls of both races, and vitamin A was most deficient in diets of boys, but the serum vitamin A and carotene values did not confirm a dietary deficiency of vitamin A. Black teenagers of both sexes had less acceptable mean hemoglobin and hematocrit values. High incidences of low hemoglobin values below acceptable range were observed in all groups studied. A high incidence of overweight among girls of both races, of high blood pressure in black boys, and of elevated serum cholesterol and beta-lipoprotein levels in blacks of both sexes were observed. Intake of energy was correlated with work metabolic rate/basal metabolic rate ratio for both sexes. Blacks were less physically active than whites. Serum cholesterol, triglyceride and beta-lipoproteins were positively correlated (P less than 0.01) to body weight of girls. Serum cholesterol and beta-lipoproteins were negatively correlated (P less than 0.05) to the degree of physical activity of boys.

Characterization and mitogenic activity of Haemophilus influenzae type B capsular polysaccharide

Studies were conducted on the characterization of Haemophilus influenzae type b polysaccharide (HITB-PS) and its mitogenic activity upon peripheral lymphocytes. This capsular polysaccharide was found to contain hexosamines and hexoses in addition to the main components of ribose and ribitol phosphate. The molecular weight of HITB-PS was determined as 585,000. The affinity constant of HITB-PS to unfractionated lymphocytes was 3.13 X 10(3) M-1 with 1.11 X 10(4) binding sites per cell. HITB-PS was found to be mitogenic for both human T and B lymphocytes. At optimum doses, a three to five fold increase in 3H-thymidine incorporation into T and B cells was observed. Higher than optimum doses resulted in suppression of this mitogenicity. The effect of concanavalin A (Con A) mitogenicity was detected in T and B cells treated with effective as well as suppressive doses of HITB-PS; the mitogenic activities of Con A and HITB-PS were found to be independent of each other.

The regulation of the immune response of mice to Haemophilus influenzae type b capsular polysaccharide

The regulation of age-related antibody response to Haemophilus influenzae type b polysaccharide (HITB-PS) was studied by measuring the splenic plaque forming cells (PFC) following immunization with this capsular polysaccharide. The magnitude of PFC response to HITB-PS was found to be dose-related, enhanced by Freund's complete adjuvant and influenced by the genetic strain of mice. Priming with a low dose of HITB-PS did not induce a state of immunological unresponsiveness. Treatment with antilymphocyte serum significantly increased the PFC response to HITB-PS. Athymic nude mice showed an enhanced ability to induce both IgG and IgA-PFC responses as well as a significant increase in the biosynthesis of protein and mitogenicity in spleen cells. These findings suggest that the immune response to HITB-PS is regulated by the suppressor T cell. The magnitude of the IgM-PFC response induced by HITB-PS in mice increased gradually from two weeks of age and reached a plateau at 8 weeks. Treatment with fetuin resulted in the inhibition of direct IgM and IgG-PFC responses to HITB-PS; the suppressive effect on the immune response was more profound and lasting in young than in adult mice.

The absence of an 8-desaturases in rat liver: a reevaluation of optional pathways for the metabolism of linoleic and linolenic acids

11-[3- -14 C] Octadecenoic acid, 11,14-[1- -14C] nonadecadienoic acid, 11,14-[1- -14 C] eicosadienoic acid, 11,14-[1- -14 C] heneicosadienoic acid and 11,14,17-[3- -14 C] eicosatrienoic acid were fed and injected into tail veins of rats raised on balanced and fat-free diets. Analysis of the total liver lipids showed that 11-ated to 5,11,14-19:3; 11,14-20:2 was desaturated to 5,11,14-20:3; 11,14-21:2 was desaturated to 5,11,14-21:3 and 11,14,17-20:3 was desaturated to 5,11,14,17-20:4. In rats raised on balanced diets 11,14-19:2 and 11,14-21:2 were desaturated at very slow rates. The 11,14-20:2 and 11,14,17-20:3 were desaturated to 5,11,14-20:3 and 5,11,14,17-20:4but not as rapidly as in rats raised on fat-free diets. These findings strongly suggest that rat liver does not have a desaturase capable of introducing a double bond in the 8-position during polyunsaturated fatty acids biosynthesis. From these studies it can be concluded that linoleate is only converted to arachidonate via the following pathway: 9,12-18:2 yields 6,9,12-18:3 yields 8,11,14-20:3 yields 5,8,11,14-20:4. Linolenate is only metabolized as follows: 9,12,15-19:3 yields 6,9,12,15-18:4 yields 8,11,14,17-20:4yields 5,8,11,14,17-20:5 yields 7,10,13,16,19-22:5 yields 4,7,10,13,16,19-22:6. Optional pathways such as 9,12-18:2 yields 11,14-20:2 yields 8,11,14-20:3 yields etc. and 9,12,15-18:3 yields 11,14,17-20:3 yields 8,11,14,17-20:4 yields etc. are inoperative because 11,14-20:2 and 11,14,17-20:3 are probably not produced in vivo and if produced may well be converted to 9,12-18:2 and 9,12,15-19:3, respectively, by retroconversion.

Lasting biological effects of early environmental influences. 8. Effects of neonatal infection, perinatal malnutrition, and crowding on catecholamine metabolism of brain

The effects of neonatal infection, perinatal malnutrition, and crowding on the metabolism of brain catecholamine were studied in specific pathogen-free mice. Metabolic turnover of catecholamine was determined by measuring the incorporation of precursor tyrosine-(14)C into brain tissue, catabolic activity of norepinephrine-(3)H at various times after intracisternal injection, and tissue levels of dopamine and norepinephrine. The rate of tyrosine incorporation was decreased by neonatal infection but was increased by perinatal malnutrition and crowding. There was no difference in catabolic activity of norepinephrine between infected, crowded, and control groups. In the malnourished group, however, the total radioactivity from norepinephrine was significantly higher than in the control group (1/2) and 2 hr after injection. The brain contents of dopamine and norepinephrine were depressed in the malnourished group. There was no significant difference in catecholamine levels between infected, crowded, and control groups. In the malnourished group, treatment of the mothers with growth hormone prevented almost completely weight loss during lactation, and also resulted in higher fetal weight. Hormone treatment restored to normal the levels of brain catecholamine and the enzymatic activity of brain tyrosine hydroxylase in progeny of malnourished mothers.

Lasting biological effects of early environmental influences. VII. Metabolism of adenosine in mice exposed to early environmental stress

The metabolism of adenosine 3',5'-monophosphate (cyclic AMP) was studied in specific pathogen-free mice exposed to neonatal infection with mouse enterovirus or to malnutrition during early life. Metabolic activity was determined by measuring the turnover of cyclic AMP-8-(14)C to respiratory (14)CO(2), its incorporation into various organs and plasma, and the binding activity of synaptosome for cyclic AMP. Early malnutrition increased the catabolism of cyclic AMP as measured by expiration in respiratory CO(2). The level of cyclic AMP was lower in plasma and its incorporation into various tissues was decreased in infected and malnourished animals. Metabolic products of cyclic AMP were isolated from plasma by ion exchange chromatography. Cyclic AMP-8-(14)C had completely disappeared 9 hr after injection. Fewer metabolites of cyclic AMP were detected in infected or malnourished groups than in controls and the metabolic reaction from 5'-AMP to adenosine seemed to be slow in these animals. The ability to incorporate cyclic AMP to synaptosome was also impaired in the experimental groups. The concentrations of brain cyclic AMP were lower in infected or malnourished animals than in controls. Depression of accumulation of cyclic AMP probably resulted from excessive activity of phosphodiesterase, rather than from impairment of adenyl cyclase. Intraperitoneal administration of theophylline brought the activity level of phosphodiesterase to normal in infected or malnourished mice; this fact probably accounted for enhanced accumulation of brain cyclic AMP.

The mouse intestinal microflora with emphasis on the strict anaerobes

The various components of the intestinal microflora in the mouse become established according to a definite time sequence; the strict anaerobes are the last groups of bacteria to reach their maximum population levels, 14-16 days after birth. The multiplication of these strict anaerobes in the mouse intestine seems to depend upon the prior multiplication of other bacterial species, and coincides with the ingestion of food other than maternal milk. These two conditioning factors may correspond to the establishment of a suitably reduced Eh potential and to the provision of certain metabolites. Once established, the strict anaerobes constitute by far the largest percentage of the total intestinal microflora; most of them are associated in a viable form with the mucosa. In normal animals they persist at very high levels throughout the life span. However, their populations can be drastically reduced by dietary manipulation of the animal, by administration of vancomycin, or by certain disease processes of the intestine. The strict anaerobic bacteria seem to play an important, and perhaps essential role in the maintenance of the anatomic structures and physiological functions of the intestine. They also seem to hold in check several species of intestinal bacteria, in particular the coliform bacilli.

Lasting biological effects of early environmental influences. VI. Effects of early environmental stresses on metabolic activity and organ weights

Specific pathogen-free mice were exposed to three different kinds of environmental stress during early life: (a) by infecting them with a mouse enterovirus on the second day after birth; (b) by placing the mother during pregnancy and lactation on a mildly deficient diet containing wheat gluten supplemented with See PDF for Structure small amounts of lysine and threonine; (c) by combining a (neonatal infection) and b (early malnutrition). All animals survived the three types of stresses, but all exhibited marked depressions of metabolic activity, and of body weights and organ weights. These depressions lasted throughout the experimental period even though all animals were placed under optimum conditions of nutrition and husbandry after weaning, and maintained under these same conditions thereafter. Metabolic activity was determined by measuring the turnover of (14)C-acetate and (14)C-glucose in respiratory CO(2), and their incorporation in total lipids of liver and brain. The utilization of (14)C-acetate was profoundly depressed in all experimental groups with regard to both elimination in respiratory CO(2) and their incorporation in total lipids of liver and brain. In contrast, the utilization of (14)C-glucose was much less affected; its incorporation into lipids was not decreased and its elimination in respiratory CO(2) was depressed only in animals having experienced both neonatal infection and early malnutrition. The extent of weight depression per 100 g of body weight differed according to the organ and the type of stress. Irrespective of the organ, however, depression of weight was largest in animals having experienced both neonatal infection and early malnutrition. And irrespective of the type of stress, the brain exhibited the smallest depression of weight relative to total body weight.