Comparative pharmacokinetics of ampicillin and carbenicillin in the cerebrospinal fluid of rabbits with staphylococcal meningitis with reference to half-lives and areas under the curve

Pharmacokinetic differences between ampicillin and carbenicillin in the cerebrospinal fluid (CSF) were evaluated in experimental staphylococcal meningitis in rabbits after a single intravenous administration of 100 mg/kg dose of each drug. Half-lives (T 1/2) in CSF and CSF/serum ratios of T 1/2 were 52 minutes and 2.1 for ampicillin and 23 minutes and 1.3 for carbenicillin, respectively. These findings indicate that ampicillin is eliminated from CSF more slowly than carbenicillin. Penetration rates were calculated from CSF/serum ratios of area under the curve (AUC) and were 16.8% for ampicillin and 11.6% for carbenicillin, although the maximum concentration (Cmax) of carbenicillin in CSF was twice as high as that of ampicillin. Thus the penetration rate appeared to be influenced more by T 1/2 in CSF than by Cmax. Cmax in CSF was obtained at 15 minutes for carbenicillin and 30 minutes for ampicillin. As to carbenicillin there were considerable individual variations in CSF levels. The above observations suggest that T 1/2 and AUC in CSF are important parameters when evaluating the usefulness of an antibiotic in the treatment of bacterial meningitis.

[Sensitivity of group B Streptococcus to various antibiotics (author's transl)]

Group B Streptococcus was isolated from the clinical materials of the patients examined in the Kobe Central Municipal Hospital, in 1974 to 1979. 1. Clinical isolates were all resistant to bacitracin. 2. Serotypes of 19 isolates were type III in 12 strains, Ia in 3, Ic in 2 and untypable in 2. 3. The MICs were determined to 15 antibiotics, and the results showed that penicillin G was the best and in the order of decreasing potency, cefotaxime, ampicillin, ceftizoxime and cefoperazone. 4. Compared with group A Streptococcus, the sensitivity of group B Streptococcus to penicillin G and ampicillin was inferior by 2 to 3 tubes. 5. Based on the above results, the significance of the cephalosporin antibiotic of the third generation, particularly cefotaxime, was evaluated in the treatment of infectious diseases of the newborn infants.

[Fundamental and clinical studies on cefadroxil dry syrup in children (author's transl)]

Fundamental and clinical studies were made on cefadroxil, a new oral cephalosporin, and the following results were obtained. (1) Antibacterial activity of the drug against S. aureus, S. epidermidis, E. coli, Klebsiella, Salmonella and P. mirabilis was almost equal to that of cephalexin. The MIC of indole positive Proteus. Enterobacter, Citrobacter, S. marcescens and P. aeruginosa to cefadroxil was higher than 100 microgram/ml in almost all strains. (2) Serum concentrations following an oral administration of 10.0 to 14.3 mg/kg of cefadroxil dry syrup was highest at 2 hours in 2 cases and 1 hour in 1 case, respectively, which were 13.4 to 17.1 microgram/ml, and 1.8 to 6.8 microgram/ml at 4 hours with an T 1/2 of 1.04 to 1.62 hours and apparently longer continuation of serum concentration than that of cephalexin. Urinary recovery rate was 75-96% up to 6 hours. (3) Fourteen patients, i.e., 6 with tonsillitis and 8 with urinary tract infection, were treated with a daily oral dose of 30-50 mg/kg divided in 4 doses except 1 case divided in 3 doses. The overall efficacy rate was 100%, i.e., excellent in 13, good in 1 and no failure. Causative organisms disappeared in all cases. (4) Adverse reactions, such as diarrhea and skin rash, were not noted at all and 1 case presented a mild elevation of GOT and GPT. (5) Taste and flavor of the drug was well palatable to children. (6) Based on the above results, it is concluded cefadroxil dry syrup is a new potent cephalosporin for oral use in the treatment of acute bacterial infection in children. Daily dose of 40 mg/kg in 3-4 divided doses appeared to be appropriate.

Human yolk sac tumor serially transplanted in nude mice: its morphologic and functional properties

Three human yolk sac tumors (TE, OE, and TT-1) were serially transplanted into nude mice. The histology of the transplanted tumors is moderately different from that of the original tumor; the transplants had mainly a tubular structure with an inconspicuous endodermal sinus structure due to a decreased mesenchymal element surrounding the vascular core. Ultrastructural features of the transplanted tumor cells, however, were identical to those of the original tumor. Immunochemical survey of the blood plasma of nude mice bearing these tumors demonstrated the production of adult type human plasma proteins including prealbumin, albumin (Alb), alpha 1-antitrypsin (alpha AT), transferrin (Tf), hemopexin, and alpha 1-fetoprotein (AFP). The types of adult plasma proteins that were produced varied, depending on the tumor line but were the same between serial passages within the same tumor line. The intracellular localization of AFP, alpha AT, Tf, and Alb was also investigated by immunoelectron microscopy. Plasma proteins of the adult type and AFP were localized mainly within the membrane systems of the endoplasmic reticulum and Golgi complex and occasionally on the microvilli. These results suggest that transplanted human yolk sac tumors have almost all of the protein-producing function possessed by their normal counterparts.

Specific changes in the cholinergic system in guinea-pig vas deferens after denervation

A small rapid phase (1st phase) was distinguished from a concomitant phase (2nd phase) in contraction of guinea-pig vas deferens. The vas deferens 4 days after denervtion exhibited supersensitivity to stimulants. The supersensitivity in the 2nd phase of contraction was nonspecific, but that in the 1st phase was specific to muscarinic cholinergic agonists. The increase in sensitivity resulted in a shift of the dose-response curve to lower concentrations without significant change in the maximal response. Muscarinic cholinergic receptors in the vas deferens, determined by measuring binding of [3H]quinuclidinyl benzilate, changed after denervation. The maximal binding sites increased from 115 to 165 fmol/mg of protein with no significant change in the dissociation constant. The affinity of the receptor for agonist also did not change significantly. Studies on [3H]WB4101 binding indicated no significant change in alpha adrenergic receptors after denervation. Thus, specific supersensitivity of the cholinergic mechanism mediated by muscarinic acetylcholine receptors occurred after denervation of guinea-pig vas deferens. This increased sensitivity is discussed in relation to the amount of receptor.

[Cefmetazole in the treatment of bacterial infections in the newborn (author's transl)]

Clinical evaluation of cefmetazole were made in the treatment of bacterial infections in the newborn infants and the following results were obtained. 1) Five infants, 7 approximately 58 days of age, received a single intravenous one-shot injection of 22.2 approximately 24.5 mg/kg dose of cefmetazole, and blood concentrations were determined. The average level was 62.6 micrograms/ml (30 minutes), 46.3 micrograms/ml (1 hour), 26.8 micrograms/ml (2 hours), 8.7 micrograms/ml (4 hours) and 2.4 micrograms/ml (6 hours), and T 1/2 was 87.7 minutes. Almost similar values were obtained when the drug was given by a 30-minute drip infusion and sufficiently exceeded the MIC to the bacteria to which cefmetazole was indicated. 2) In two patients, who had been operated for choledochal cyst and received an intravenous drip infusion of the drug, the persistence of the blood concentration was remarkably long, T 1/2 being 192 and 222 minutes, respectively. This problem still remains to be elucidated. 3) The following 22 patients were treated with an intravenous one-shot or drip infusion of cefmetazole, i.e., 45.6 to 107.1 mg/kg divided in 2 approximately 3 doses; 14 patients aged 1 to 21 days, 2 aged 1 to less than 2 months, 3 aged 2 to less than 3 months and 3 aged older than 3 months. However, in purulent meningitis, larger dose was given intravenously 6 times daily. Diseases included sepsis (4 cases), purulent meningitis (3), peritonitis (1) SSS syndrome (3), subcutaneous abscess (2), urinary tract infection (8) and Salmonella enteritis (1), and their causative organisms were E. coli (13 strains), K. pneumoniae (1), S. typhimurium (1), S. aureus (6) and group B Streptococcus (1). Overall efficacy rate in 22 cases was 90.9%. i.e., excellent in 11, good in 9 and failure in 2. Two cases of failure were a patient with peritonitis and visceral eventration due to umbilical hernia and a patient with a chromosomal aberration and urinary tract infection caused by E. coli. Reasons for such a treatment failure appeared to reside in host factors. 4) Adverse reactions included each one case of skin rash and diaper rash, 3 cases of eosinophilia and 5 cases of elevation of transaminase levels, all of which were mild and transient. 5) Based on the above results, cefmetazole is considered to be a potent new antibiotic which should be indicated as the first choice drug in the treatment of neonatal bacterial infections. The recommended dosage is as follows: 50 mg/kg given intravenously 6 times daily for bacterial meningitis and 20 approximately 25 mg/kg intravenously or by a drip infusion 2 to 3 times daily for other infections.

Muscular changes in Engelmann's disease

In a case of Engelmann's disease in an 11-year-old Japanese boy the muscular changes were studied in detail. Muscle weakness was maximal about the pelvic girdle. Muscle biopsy showed the selective atrophy of type II fibres, and no degenerative change could be seen histologically, histochemically, or electron-microscopically. Although the distribution of muscular weakness in Engelmann's disease is similar to that of a progressive muscular dystrophy, the disease does not seem to be a myopathy.

[Clinical evaluation of cefoperazone in children (author's transl)]

Clinical evaluation was made on cefoperazone (CPZ) and the following conclusions were obtained. (1) Serum concentrations of the drug after a one-shot intravenous injection of 22.2 mg/kg were 77 mcg/ml (30 minutes), 50 mcg/ml (1 hour) and 8.9 mcg/ml (4 hours) and T 1/2 of serum concentration was 68.5 minutes. A 35-day-old female with obstructive jaundice associated with choledochal cyst was given by a 30-minute drip infusion of 26.8 mg/kg of the drug. Serum concentration was 90 mcg/ml at the end of infusion, slowly declined thereafter, and was 47.5 mcg/ml at 6 hours. Its T 1/2 was 395 minutes. A patient with pyelonephritis complicated with right hydronephrosis was similarly treated with 24.4 mg/kg. T 1/2 of serum concentration was not prolonged, i.e., 82.1 minutes, but urinary recovery rate up to 6 hours was decreased to 15.9%. (2) Five patients, including three with pyelonephritis (causative organism: K. pneumoniae 2 and P. aeruginosa 1) and each one patient with pneumonia (unknown) and with postoperative infection (S. faecalis), respectively, were treated with 66.7 approximately 96.8 mg/kg/day of CPZ in 3 divided doses for 5 approximately 12 days either by one-shot intravenous or by 30 approximately 60-minute drip infusion. An overall efficacy rate was excellent in 3 and good in 2, and there was no failure. Causative organisms disappeared in all cases. (3) Although one patient was excluded from the study because the diagnosis was supposed to be viral pneumonia, all six patients who were given CPZ did not exhibit any adverse reactions except for mild eosinophilia in two instances. (4) The foregoing results as well as the review of the literature clearly indicate the effectiveness of CPZ in the treatment of bacterial infections in children.

A quantitative study of acetylcholine in Hirschsprung's disease

This is the first report on acetylcholine (Ach) quanititaion of the aganglionic colon by a chemical assay. Ach content in the colon of Hirschsprung's disease was measured by pyrolysis gas chromatography, which was found to be a simple, accurate, and reliable method. Microwave irradiation on the surgical resected specimens was performed before extraction procedure to abolish acetylcholinesterase (Ach-E) and cholineacetyltransferase (CAT) activity in the tissue. Ach content in the ganglionic colon was 8.51 +/- 3.15 nmole/g (n 5 in contrast to 23.79 +/- 14.17 nmole/g (n = 19) in the aganglionic segment of Hirschsprung's disease. The meaning of elevated Ach level in the aganglionic segment was discussed from the pathophysiologic standpoint.

Multicystic encephalomalacia in liveborn twin with a stillborn macerated co-twin

Computed tomography showed multiple cystic lesions in the brains of three infants with cerebral palsy. Each patient was the product of a twin pregnancy with a stillborn, macerated co-twin. In two patients angiography was performed and suggested that the cystic lesions were multicystic encephalomalacia due to perinatal arterial occlusion.

Manometry and histochemistry in the diagnosis of Hirschsprung's disease

Acetylcholine esterase histochemistry and rectal manometry have been used sequentially to evaluate constipated children and to make the diagnosis of Hirschsprung's disease. When applied together, these modalities give a reliable diagnosis of Hirschsprung's disease, restricting the use of deep rectal biopsy to those patients in whom symptoms are most suggestive of Hirschsprung's disease. Acetylcholine esterase histochemistry may be more reliable than rectal manometry in the newborn and premature periods. It is hoped that the combined use of these techniques may make deep rectal biopsy obsolete except in patients with hypoganglionosis.

[Treatment of E. coli meningitis with cefmetazole. Report of two cases with favorable response and determination of the concentrations in CSF (author's transl)]

Two patients with purulent meningitis, of which causative organism was presumed to be E. coli, were treated with intravenous administration of cefmetazole, 300 approximately 400 mg/kg/day in 4 approximately 6 divided doses, and the following conclusions were obtained. 1) Clinical response was favorable and a complete cure was obtained without sequelae in both patients. There were no adverse reactions noted except for a mild and transient eosinophilia (12%) in one case. 2) Of two strains of E. coli recovered from CSF, one was sensitive to ampicillin, cefazolin and cefmetazole, among which cefmetazole had the highest bacterial activity. Although another strain was sensitive to cefmetazole, it showed resistance to cefazolin (greater than 12.5 microgram/ml) and to ampicillin (greater than 100 microgram/ml). 3) Concentrations of cefmetazole in CSF following 1 approximately 2 hours of its intravenous administration were either equal to or higher than those of ampicillin, which was given to the same patient for a short period of time. The concentrations in CSF were higher than 3.1 microgram/ml on each occasion except for in some specimens during the convalescent phase and exceeded well the MIC of the causative organism. 4) Based on the above results, cefmetazole is considered to be a potent antibiotic in the treatment of E. coli meningitis. Although further studies are needed as to the dosage, an intravenous administration at 4-hour interval appears to be warranted based on the studies that the half-life of the drug is short in CSF in animal experiments.

Studies of the nonspecific cellular immune response in patients with urinary bladder carcinoma. II. Immunodepressive effect of sera from bladder carcinoma

In vitro reactivity of normal lymphocytes in various sera was determined by quantitation of phytohemagglutinin (PHA)-induced tritiated thymidine incorporation rate (counts per minute). Sera were obtained from normal subjects, fetal calf, and patients with bladder carcinoma. The rate of lymphocyte blastogenesis was expressed as a stimulation index (SI) that was calculated by dividing the number of counts per minute with PHA by that without PHA. The effect of sera on blastogenesis of normal lymphocytes was expressed as percent change (%SI) per SI with fetal calf serum. The SI of normal lymphocytes was similar in autologous serum (26.7 +/- 11.6), fetal calf serum (25.4 +/- 11.8), and heat-inactivated homologous normal AB serum (28.8 +/- 11.4). The SI of normal lymphocytes in sera from patients with bladder carcinoma was significantly lower than in the other two sera (14.0 +/- 7.9). The serum inhibitory effect was significantly associated with the stage and grade of tumor and was diminished after removal of the tumor. The SI of lymphocytes from patients with certain other malignant diseases was significantly lower in autologous serum than in fetal calf serum or homologous normal AB serum. The SI of the lymphocytes from patients with prostatic carcinoma and embryonal cell carcinoma was also low in sera from patients with bladder carcinoma as well as in autologous sera. It is likely that the depressive effect of sera from patients with bladder carcinoma was not specific to bladder carcinoma.

Studies of the nonspecific cellular immune response in patients with urinary bladder carcinoma. I. PHA-induced lymphocyte transformation

The nonspecific cellular immune response, as measured by phytohemagglutinin (PHA)-induced blastoid transformation of peripheral lymphocytes in autologous serum, was evaluated in 119 patients with bladder carcinoma and in 21 control subjects. Blastoid transformation was determined by quantifying 3H-thymidine incorporation (counts per minute). The rate of blastogenesis of lymphocytes was shown as the stimulation index which was calculated by dividing the number of counts per minute with PHA by that without PHA. The stimulation index of the control subjects was 29.9 +/- 6.6 (+/- SD); that of the experimental group was 13.3 +/- 7 (significantly lower reactivity). There was a converse correlation between the stimulation index and the grade and stage of tumor. In some cases the change in cellular immunity was compared before and after surgery.

Penicillin G production by immobilized whole cells of Penicillium chrysogenum

Penicillium chrysogenum was immobilized in polyacrylamide gel prepared from 5% acrylamide monomers (85% acrylamide and 15% N,N'-methylene bisacrylamide). Penicillin produced from glucose by the immobilized mycelium was 17% of that produced by washed mycelium. However, the activity of penicillin production of the washed mycelium decreased with repeated use. On the other hand, the activity of the immobilized mycelium increased initially and decreased gradually with repeated use. The rate of oxygen uptake of the immobilized mycelium was about 30% of that of the washed mycelium. The immobilized mycelium required oxygen for the production of penicillin.

Bacitracin production by whole cells immobilized in polyacrylamide gel

Whole cells of Bacillus sp., bacitracin-producing bacteria, were immobilized in polyacrylamide gel prepared by using 5% total acrylamide (95% acrylamide monomer and 5% N, N'-methylenebis acrylamide). Bacitracin production by the immobilized whole cells was examined by using various fermentation media. In starch-bouillon medium, the initial activity of immobilized whole cells for bacitracin production was 20 to 25% that of an equivalent amount of washed cells. With successive utilizations in 1% peptone as reaction medium, activity of the immobilized whole cells increased gradually and reached a steady-state maximum having a value of 80 to 90% of the activity obtained initially with washed cells, whereas the washed cells lost most activity when utilized successively. What appeared to be growth of the bacteria in the gel was observed by electron microscopy. Therefore, the activation of immobilized whole cells during successive utilizations apparently resulted from the growth of whole cells in the gel, especially at the gel surface.

Light- and electron-microscopic studies on the gastric parietal cells in perinatal rats. Effects of fetal and neonatal oral administration of milk

Perinatal changes of the gastric parietal cells were studied under normal and various experimental conditions. Histologic examination revealed that the parietal cells appeared markedly increased in number from late fetal to early neonatal days. When premature newborn rats were delivered by cesarean section and were nursed by foster mothers for 1 or 2 days, the degree of increase of these cells reached nearly that in the normal neonates. On the other hand, in fetuses retained in utero 1 day beyond the normal gestation, these cells appeared not increased in number. When these postmature fetuses were delivered, the parietal cells turned to increase in number in a degree similar to that in the normal neonates. Milk given to the premature newborn rats caused 6 h later a marked increase in the number of the parietal cells. Milk given to fetuses in utero also caused an increase of these cells. The results suggest that the development of the parietal cells in perinatal rats is accelerated by the intake of milk and that the fetal parietal cells are ready to respond to milk given at least 1 day before birth.

Studies on 15-hydroxyprostaglandin dehydrogenase with various prostaglandin analogues

The NAD+-linked 15-hydroxyprostaglandin dehydrogenase (PGDH) of swine lung was purified to a high specific activity by affinity chromatographies on prostaglandin (PG)-and NAD+-Sepharose. The affinities of the enzyme for various synthetic analogues of PGA, E, F, and I and their inhibitory effects on the enzymatic reaction were examined. The modification of the alkyl side chain of PG, particularly at C-15 or C-16, reduced the affinity of the enzyme for these PG analogues. Furthermore, 14-methyl-13,14-dihydro-PGE1 and 16-cyclopentyl-omega-trinor-15-epi-PGE2 were potent inhibitors of PGDH.

Cholinergic nerve development of fetal lung in vitro

The development of the cholinergic or parasympathetic nervous system was studied in embryonic lung dissociated from the central nervous system and placed in organ culture. In vitro development was similar to that seen in vivo. This study demonstrated that migration of neuroblasts from the central nervous system to the trachea takes place before day 12. Neuroblasts differentiate to small immature ganglia and then to larger more mature ganglia that give off nerve fibers to the submucosa and the epithelium. This isolated lung preparation was used to study neurostimulators. Thyroxine (T4) was found to accelerate nerve fiber growth and differentiation of ganglia in vitro. The neuroepithelial body, an epithelial cell with acetylcholine-esterase-positive granules, also differentiated in vitro. This cell may fill the morphologic criteria of an intrapulmonary chemoreceptor.

[Experimental studies on the passage of antibiotics into cerebrospinal fluid in staphylococcal meningitis in rabbits. II. Cephaloridine, cephalothin and cefazolin (author's transl)]

Passage of cephaloridine, cephalothin and cefazolin into cerebrospinal fluid (CSF) was evaluated in Staphylococcus aureus meningitis in rabbits and the following results were obtained. 1. Concentration in CSF (microgram/ml) [CSF/serum ratio (%)] was determined 1/2, 1 and 2 hours after a single intravenous injection of 100 mg/kg of each antibiotic, respectively; cephaloridine-7.5 [8.9], 9.7 [13.8], 9.1 [22.6]; cephalothin-0.42 [3.6], 0.23 [6.4], not detectable [0]; cefazolin-7.5 [11.8], 5.2 [19.3], 2.0 [17.5]. 2. When results with cefazolin after an intravenous injection 100 mg/kg and 200 mg/kg were compared, a definite dose response was noted in blood concentration but not in CSF concentration. 3. A standard error of CSF concentrations of each antibiotic was larger than that of penicillins, and "Unpredictability" of their passage into CSF was considered to be one of the characteristics common to these three drugs in respect of their passage into CSF. 4. There was no significant difference noted in antibiotic passage into CSF between cephaloridine of low protein binding rate and cefazolin of very high binding rate. Cephalothin, of which binding rate was intermediate, showed a remarkably lower passage into CSF. These results indicate that a correlation does not always exist between protein binding rate of the antibiotics and their passage into CSF. 5. Based on the above results, a review of the literature was made on clinical applicability of these three antibiotics in the treatment of bacterial meningitis. Low transport rate of cephalothin into CSF and nephrotoxicity of cephaloridine make them to be unsuitable for bacterial meningitis. Cefazolin is considered to be suitable in the treatment of ampicillin-resistant Escherichia coli meningitis and Gram-positive coccal meningitis in which penicillins are not applicable.

[Clinical evaluation of intravenous administration of ampicillin-oxacillin (Broadcillin 'Banyu') in bacterial infections in children (author's transl)]

Broadcillin 'Banyu', which contains an equal amount of ampicillin and oxacillin was given intravenously to children with acute bacterial infections and the following results were obtained. 1. Patients were 55 children with the following bacterial infections; respiratory tract infections (8 cases), pneumonia (34), sepsis (1), meningitis (1), cutaneous and subcutaneous suppurative inflammation (5), osteomyelitis (1), urinary tract infection (2), enteritis (1), and chemoprophylaxis (2). They ranged in age from newborns to 8 year old, but most of them were infants. In the majority of the patients, broadcillin 'Banyu' was administered 50 approximately 150 mg/day in three to four equally divided doses by one shot-injection or by a continuous drip infusion for a period of 2 approximately 10 days. The overall efficacy rate was 88.7% in 53 cases after two cases of chemoprophylaxis were excluded, i.e., excellent in 28, good in 19 and failure in 6: excellent in 4 and good in 4 in 8 cases of respiratory tract infections; excellent in 20, good in 11 and failure in 3 in 34 cases of pneumonia (an efficacy rate 91.2%); failure in sepsis and meningitis: excellent in 2 and good in 3 in 5 cases of cutaneous and subcutaneous suppurative inflammation; excellent in osteomyelitis; excellent in 1 and good in 1 of 2 cases of urinary tract infection; failure in enteritis. 2. Adverse reactions were noted on 10 occasions in 9 cases (16.4%), including 1 case of skin eruption, 1 case of eosinophilia, 5 cases of slight elevation of GOT, 1 case of slight elevation of GPT and 2 cases of slight elevation of BUN. 3. Based on the above results, it was concluded that clinical effect of broadcillin 'Banyu' by an intravenous administration is comparable to its intramuscular route and that safety of intravenous usage seems to be verified as long as the above described dosage is followed.

NAD recycling in the collagen membrane

NAD recycling in the collagen membrane was investigated as follows: (1) Alcohol dehydrogenase and lactate dehydrogenase were co-immobilized in the collagen membrane and the rate of lactate production by immobilized enzymes was compared with that of free enzymes by using free NAD. An increased rate was observed in the case of immobilized enzyme. (2) The soluble high molecular weight derivatives of NAD (dextran-NAD) were immobilized in the collagen membrane with the two dehydrogenases and recycling of dextran-NAD in the membrane was examined. Lactate was produced by the membrane without adding free NAD. The interaction between the high molecular weight NAD derivatives and enzymes are also discussed.

Development of the fetal pituitary-testicular system based on the observation of Leydig cells in encephalectomized, hypophysectomized and control fetal rats

The time of onset of brain regulation of the pituitary-Leydig cell system in fetal rats was assessed by fetal encephalectomy, which allowed the pituitary to persist in situ. The effects of encephalectomy were compared with those of fetal hypophysectomy (surgical decapitation). The parameter for interpretation of these effects was the collective volume of Leydig cells, measured by the method of Chalkley ('43). The normal increase in the collective volume of Leydig cells in fetuses encephalectomized on day 17 of gestation and autopsied on day 18 was not retarded, whereas that in decapitated fetuses of the same age was retarded. In all other one-day experimental periods (day 18-19, 19-20, 20-21, and 21-22), the increase in volume was retarded to approximately the same extent in encephalectomized as in decapitated fetuses. The collective volume of Leydig cells continued to increase to some extent without the brain until day 20, after which it ceased to increase. The results suggest that in fetal rats, the brain control of the pituitary-Leydig cell system begins to operate from day 18 of gestation, when the day following overnight mating was designated as day 1 of gestation.

Changes in placental permeability to corticosterone and estradiol-17beta toward the end of gestation in the rat

Radioactivity in the fetal plasma 1 h after maternal injection of 14C-4-corticosterone or 14C-4-estradiol-17 beta on day 21 of gestation was markedly higher than that 1 h after injection on day 22. Radioactivity in the maternal plasma was not different on these 2 days. The results suggest that the placental permeability to steroids from the mother to the fetus declines toward the end of gestation in the rat.

Increased secretion of Müllerian inhibiting substance after immunological blockade of endogenous luteinizing hormone releasing hormone in the rat

In order to evaluate the role of leuteinizing hormone releasing hormone (LHRH) and gonadotropins in the control of secretion of Müllerian inhibiting substance, groups of pregnant rats were injected intraperitoneally with high potency antiserum from a rabbit immunized with LHRH. Pregnant females were injected at 13 and 20 days of gestation with LHRH antiserum or an equal volume of normal rabbit serum as a control. The testes and penis were reduced in weight and size in 6-day-old pups of the experimental group indicating the luteinizing hormone (LH) was blocked and that LHRH antiserum was active. Testicular fragments of 17-day fetuses and 6-day-old pups showed an increase relative to controls in Müllerian inhibiting substance activity in a graded organ culture bioassay system. These studies suggest that secretion of Müllerian inhibiting substances is curtailed by one or both gonadotropins.

Mullerian inhibiting substance in human testes after birth

Tiny testicular biopsies from humans were assayed for Mullerian inhibiting Substances using a graded organ culture technique. Mullerian Inhibiting Substance activity was high during the first year of life, declined during the second year of life, and then disappeared. Mullerian Inhibiting Substance activity is lower in boys with undescended testis than in children with normal or intersex testes at comparable ages under two years. It is possible that Mullerian Inhibiting Substance affects testicular descent as well as causing Mullerian duct regression.

Effect of maternal malnutrition on matrix cell proliferation in the cerebrum of mouse embryo: an autoradiographic study

Thirty pregnant mice were undernourished by providing low protein diets (PM) or providing approximately one-third their normal diets (PCM) for 9 days from the 8th to the 16th day of gestation. Another 15 pregnant mice, which were fed a normal diet, served as the control. On the 16th day of gestation, all animals were injected with a single does of [3H]thymidine and were killed one by one at 1- or 2-hr intervals. Mean litter size was statistically insignificant between the control group and two malnourished groups. There was, however, a significant difference in mean body weight between the control group and two malnourished groups (P less than 0.005). The cerebral cortex at this stage of development consisted of three different layers, i.e., the cortical plate, the migratory zone, and the matrix layer. The width of the cortical plate of the malnourished embryos was significantly smaller (P less than 0.001). There was, however, no significant difference in width of the migratory zone between the control and the malnourished groups. The width of the matrix layer in PM was significantly smaller (P less than 0.001), but that of PCM showed no significant difference from the control (P greater than 0.1). Coronal section of the brains of the embryos were processed for autoradiography. Labeled cells were found almost exclusively at the matrix layer surrounding the lateral ventricels. Labeling index counted in the matrix layer after 1 or 2 hr of [3H]thymidine injection indicated that more than 30% of the cells in this layer were always synthesizing DNA in each group of embryos. The generation times of the matrix cell, precursor of the neurons, in the matrix layer were approximately 18.5 hr in the control and 21.5 hr and 21.8 hr in the malnourished embryos, thus indicating about 3 hr of prolongation in the latter. DNA synthetic time was about 6.5 hr in the control and 7.0 hr and 7.0 hr in the two malnourished groups. The postduplication time was about 2.5 hr in the control and 3.0 hr and 3.5 hr in the malnourished. The preduplication time was about 8.8 hr in the control and 10.6 hr and 10.3 hr in the malnourished.

Rise of plasma corticosterone concentrations in rats immediately before and after birth and in fetal rats after the ligation of maternal uterine blood vessels or of the umbilical cord

Just before normal vaginal delivery the plasma corticosterone concentration (PCC) in fetal rats increased markedly compared with that on day 22 of gestation. The PCC was elevated 2 h after birth and then declined until 12 h after birth, when it approached the level found on day 22 of gestation. Similarly, in premature newborn rats obtained by cesarean delivery on days 21 and 22 of gestation, the PCC increased 2 to 4 h after delivery and then declined. The PCC in 22-day-old fetal rats, 30 min after ligation of the maternal blood vessels running along a uterine horn, rose markedly compared with that in fetuses in the contralateral intact horn. A similar increase in PCC was not observed in either decapitated or encephalectomized fetuses, but observed in fetuses whose umbilical cords were ligated. The rise in fetal PCC after ligation of uterine blood vessels and of umbilical cords was considerably higher than that observed after various stresses reported by other investigators and also higher than that found 60 min after maternal adrenalectomy. The rise in PCC just before and just after birth and after the ligation should not be considered as the result of stress, parturition or ligation, but may be a result of the response to other factors.

Granularity of cells in the juxtaglomerular apparatus in fetal rats after maternal nephrectomy or fetal unilateral nephrectomy

Granular cell indices (GCI: Dunihue and Robertson, '57) in kidneys of fetal rats one day after maternal nephrectomy of fetal unilateral nephrectomy on day 21 of gestation were determined by examining sections stained with Bowie's technique. Maternal nephrectomy induced an extreme increase of GCI in fetal kidneys with increased granularity of cells in the juxtaglomerular apparatus. Fetal unilateral nephrectomy did not cause any significant change.