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Biomedical subjects

T Nakamoto

Publications and source records attributed to T Nakamoto.

At least 163 records · Page 9Linked to original sources
PubMed1987

Effect of protein malnutrition and maternal caffeine intake on the growth of fetal rat brain.

Pregnant dams were divided into two subgroups on day 10 of gestation. Half were fed a 20% protein diet and the other half an 8% protein diet. A second group also subdivided was pair-fed with rats of the first group. Their diet was supplemented with caffeine in amount calculated to provide daily doses of 2 mg/100 g body weight. On days 18, 20, and 22 randomly selected dams were injected with 3H-thymidine intraperitoneally and 1.5 h later their fetuses were delivered surgically in order to determine the rate of DNA synthesis along the gestation. The rest of the fetuses were delivered surgically on day 22. Pups' brains were rapidly removed and DNA, RNA, protein and 3H-thymidine uptake were studied. Average body weights of the fetuses in the caffeine-supplemented control group were smaller than those of the noncaffeine group. Effects of caffeine that were similar in both diet groups included a decrease in brain DNA content and concentration and an increase in brain protein content and concentration. However, the percent decrease and increase, respectively, was different depending on the nutritional status. DNA synthesis was not affected by malnutrition or caffeine supplementation on day 18 of gestation. Caffeine's effect on the rate of DNA synthesis was different on day 20 of gestation depending on nutritional status. Caffeine supplementation resulted in a decrease in DNA synthesis in both groups on day 22 of gestation. These data indicate that caffeine intake during pregnancy produces differential effects on fetal rat brain depending on dietary protein content.

Animals↗
PubMed1987

Effect of chronic caffeine intake on myocardial function during early growth.

The purpose of these studies was to evaluate the effects of chronic caffeine ingestion on the myocardium during fetal and neonatal growth and development. The isolated perfused working heart preparation was used to evaluate cardiac function. During gestation and lactation, one group of dams consumed a caffeine supplemented diet (10 mg/kg/day). Their offspring were sacrificed and the hearts analyzed 50 days after birth. We found that the intake of caffeine by the dams resulted in significant increases in the offspring's coronary flow, peak systolic pressure, and myocardial work. A second group of dams ingested a diet containing caffeine (10 mg/kg/day) during lactation only. Their pups continued to consume the caffeine diet until 50 days. Pup hearts exhibited significant reductions in cardiac output, stroke volume, pressure development, myocardial work, and external efficiency when compared to controls. Caffeine did not affect body or heart weight or adipose size or number in these experiments. Thus, continued caffeine consumption following birth may alter cardiac performance of the offspring.

Adipose Tissue↗
PubMed1987

Protein profiles of benign hypertrophic prostate: stroma-abundant distribution of BPH-associated nonhistone proteins.

Mechanically isolated epithelium and stroma from benign hypertrophic prostates were highly pure on the basis of histochemical and biochemical criteria. By electrophoretic analyses, whole cellular and nuclear proteins were compared among whole tissues, epithelium, and stroma. The characteristic protein profiles of benign hypertrophic prostates were reflected in the electrophoretic patterns of the stroma. Two-dimensional gel electrophoretic patterns of the epithelium were different from those of the stroma with exception of about 18 major spots that were common to both fractions. Of the protein species separated, 35K/6.7 (molecular weight/pI) and 36K, which was composed of two species with pI of 4.4 and 4.6, were abundant in the epithelium and stroma, respectively. Nuclei prepared from whole tissues of benign hypertrophic prostates contained three kinds of nonhistone proteins (NHP) closely associated with benign prostatic hypertrophy (BPH); 42 K-NHP, 55 K-NHP and 190 K-NHP. Electrophoretic analysis of the nuclear proteins revealed that all the BPH-associated nonhistone proteins were abundantly distributed in the nuclei of the stroma.

DNA↗
PubMed1987

Maternal low-carbohydrate high-protein diet affects mandibular growth in diabetic newborn rats.

Dams with 7 pups each were randomly assigned to two different diets. Twelve dams were fed a normal (20%) protein diet and were divided into two groups of 4 and 8 animals. Pups from group 1 (n = 28) were injected with citrate buffer as a control. Pups from group 2 (n = 56) were injected with streptozotocin. Twelve additional dams were fed a 40% protein diet. They were also divided into two groups of 4 and 8 animals. Pups from group 3 (n = 28) were injected with citrate buffer as a control. Pups from group 4 (n = 56) were injected with streptozotocin. Forty-eight hours later, diabetic status was determined using Dextrostix. On Day 15, pups were injected with [14C]proline to determine collagen synthesis and 45Ca to study mineralization. After the pups were killed, blood glucose levels were determined. Then mandibles were removed. Milk from each dam was also collected after injection of oxytocin. At the time of killing, blood glucose levels in diabetic pups were less than earlier levels, though still higher than those of controls on either diet. The weights of body and mandible, collagen contents, and the total calcium contents in the diabetic group were in general less than those of the nondiabetic group on the 20 and 40% protein diets. 45Ca uptake in the diabetic group was significantly increased compared with those of the nondiabetic rats on both diets. The percentage reduction in the mandibles of diabetic rats from those of nondiabetic rats on the 40% protein diets was consistently less than that of animals on the 20% protein diets. The higher protein contents of the maternal milk in the 40% protein group may partly be responsible for the smaller impairment of mandibular development in the diabetic over nondiabetic animals. It is concluded that maternal low-carbohydrate high-protein diets will play indirectly a beneficial role in the development of the mandibles of diabetic newborns.

Animals↗
PubMed1987

Effects of maternal dietary protein on the mandibular growth of fetuses from diabetic dams.

The effects of maternal diabetes on the mandibles in the fetuses of dams given a normal (20% protein) diet vs those given a high protein (40% protein) diet were studied. On day 9, the controls, groups 1 and 3, were injected with citrate buffer and fed a 20% and 40% protein diet, respectively. Groups 2 and 4 were injected with 40 mg/kg B.W. of streptozotocin and pair-fed with groups 1 and 3 with a 20% and 40% protein diet, respectively. On day 22, fetuses were removed. Dissected mandibles were weighed and analyzed for DNA, protein, Ca and hydroxyproline contents. Some dams in each group were injected with either 45Ca or 14C proline to study 45Ca uptake and collagen synthesis. The body and mandibular weights of the fetuses from diabetic (D) dams were smaller than those of the non-diabetic (ND) group in both diets. The protein and hydroxyproline contents of the mandible in the D 20% group was less than the ND. Hydroxyproline content from the D 40% group was less than the ND. The Ca content in the D 40% group was less than the ND. The present study indicates that metabolism in the bone of fetuses whose D dams were fed a high protein diet is affected beneficially in some parameters but not in others.

Animals↗
PubMed1986

Immunocytochemical study on fibrous sheath formation in mouse spermiogenesis using a monoclonal antibody.

One of the components of the fibrous sheath was localized in the spermatids by the immunocytochemical method using the monoclonal antibody, K32, against the fibrous sheath of mouse mature epididymal sperm. The K32 immunoreaction was first detected in the cytoplasm of spermatids at stage 14 and appeared to increase in intensity at stage 15. At this stage, the framework structure of the fibrous sheath was formed completely in the tail, but the positive reaction in the fibrous sheath was observed only in the proximal portion of the principal piece. This change in the antigenicity of the fibrous sheath proceeded in a proximal to distal direction, which was opposite to the mode of formation of the framework structure in the fibrous sheath. Finally, the entire fibrous sheath strongly reacted to the K32 antibody at stage 16, while the reaction in the cytoplasm ceased to occur. These observations indicate that the fibrous sheath matures with immunologically detectable changes in its components following formation of the framework structure. In consideration of the retrograde progression of the cytoplasmic reaction, the fibrous sheath components may possibly be transported from the spermatid cytoplasm into the principal piece.

Animals↗
PubMed1986

Transverse septum-like plaque of Peyronie's disease in a young man.

An unusual case of Peyronie's disease in a 22-year-old male is presented. The patient complained of sluggish erection of the pendulous portion of the penis. A fibrous plaque in the tunica albuginea at the base of the penis extended into the corpus cavernosum cross-sectionally. Histology was consistent with Peyronie's disease. Some improvement was obtained by partial excision of the plaque.

Adult↗
PubMed1986

Protein-energy malnutrition in rats during pregnancy modifies the effects of caffeine on fetal bones.

The mandibles and long bones of newborn rats were analyzed for the effects of maternal caffeine consumption and protein-energy malnutrition. On d 13 of gestation, dams were randomly picked and divided into four groups. Group 1 received a 20% protein diet ad libitum. Group 2 was pair-fed with group 1 a 20% protein diet with a caffeine supplement (2 mg/100 g body wt). Group 3 received a 6% protein diet ad libitum. Group 4 was pair-fed with group 3 a 6% protein diet with caffeine. Within 8 h of delivery, all pups were weighted. Randomly selected pups were injected with 14C proline to study collagen synthesis of bones. Other pups were injected with 45Ca to study mineralization of bones. Although the average litter size from the 20% protein groups with or without caffeine did not show much variation, fetal resorption and stillbirths were higher in litters from group 4 compared to those from group 3. The mandibular weights of pups from group 2 was less than those from group 1, whereas weight of long bones of those from group 4 was heavier. The rate of collagen synthesis and calcium content of the mandible of group 4 and 45Ca uptake of the mandible of groups 2 and 4 were greater than that of the corresponding noncaffeine group. The rate of collagen synthesis, hydroxyproline content, 45Ca uptake and calcium content of the long bones of groups 2 and 4 were greater than that of the noncaffeine groups. The findings suggest that nutritional factors and the effects of caffeine are closely interrelated in the growth and development of the fetus and bone in newborn rats.

Animals↗
PubMed1986

Chronic caffeine intake by rat dams during gestation and lactation affects various parts of the neonatal brain.

Timed-pregnant rats were randomly divided into 2 groups on day 13 of gestation. Group 1 received a 20% protein diet. Group 2 was pair-fed to group 1 with a 20% protein diet containing caffeine (1 mg/100 g body weight). At parturition, the dams of each group were continued on their respective diets until day 22 postpartum. At the time of weaning (day 22), only male rats were continued in the study. At this time, rats from both groups were fed the control diet containing 20% protein. On day 57 and 58, rats were killed, the brains divided into six areas, and DNA, RNA and protein contents were measured. In certain areas of the brain, weight, cholesterol, DNA, RNA and protein contents were different even long after returning to the caffeine-free control diet. The present study demonstrates that even if a relatively small amount of caffeine is taken during gestation and lactation, a time during which the growth rate is greater than in any other period of life, certain areas of the brain may be affected. These findings suggest that future central nervous system impairment may be expressed later in life in these offspring.

Animals↗
PubMed1985

Effects of orally-administered caffeine on the growth of tooth germs in protein-energy malnourished newborn rats.

Lactating dams with 8 suckling pups were fed either a 6 or 20 per cent protein diet from the birth of the pups to day 15. Pups were divided into caffeine and non-caffeine groups and, every other day between days 3 and 13, were either intubated with caffeine (1 mg/100 g body wt) dissolved in 0.1 ml physiological saline solution, or 0.1 ml saline solution as a control. At day 15, the weight of incisors and molar germs, hydroxyproline content, collagen synthesis and calcium contents were determined. Nutritional factors exercised consistent effects on all the parameters, but effects attributable to caffeine intubation were minor. There was lower molar weight in the 20 per cent protein group with caffeine, and collagen synthesis of incisor and molar germs in the caffeine and non-caffeine animals in the 6 and 20 per cent group were different. These parameters showed a significant interaction between nutrition and caffeine. Thus the direct administration of a small amount of caffeine to newborns causes only slight effects on tooth-germ development under some nutritional conditions.

Administration, Oral↗
PubMed1985

Effects of maternal caffeine intake on the growth of rat tooth germs in protein-energy malnourished neonates.

Fourteen rat dams with 8 pups each were fed either a 6, 12 or 20 per cent protein diet upon birth. Another group of 12 dams with the same number of pups was pair-fed either a 6, 12 or 20 per cent protein diet supplemented with caffeine (2 mg/100 g body weight). At day 15, randomly-selected pups were injected with [14C]-proline to determine collagen synthesis of the incisor and molar tooth germs. Another group of pups was used to determine calcium content of these tooth germs. Body weight, incisor weight and total calcium contents of tooth germs of pups from dams fed with 6 per cent protein diet were greater in the caffeine-supplemented group, whereas in the 20 per cent protein diet with caffeine group, these parameters were lower. The molar weights of the 12 per cent protein diet with caffeine animals were greater than the 12 per cent group without caffeine. The total hydroxyproline content of the incisor tooth germs from animals in the 12 per cent protein diet with caffeine was greater than is the non-caffeine group. However, total hydroxyproline of the molar tooth germs in the 20 per cent protein groups with caffeine was less than in the non-caffeine group. The rate of collagen synthesis of the incisor and molar tooth germs showed no difference in the presence or absence of caffeine in the 6, 12 and 20 per cent protein groups. Incisor and molar tooth germs are thus affected differently by the interaction of protein and caffeine, possibly due to differences in the pattern of tooth development.

Animals↗
PubMed1985

Treatment of bladder carcinoma in patients more than 80 years old.

We reviewed 26 patients more than 80 years old with bladder carcinoma to determine if an active surgical policy is justified. Ten patients with superficial carcinoma were treated with transurethral resection; none died of cancer and half have survived 5 years. Of 16 patients with invasive carcinoma 9 underwent total cystectomy with urinary diversion and 2 underwent partial cystectomy. There was no operative mortality. Postoperative complications were not serious. Five of the 9 patients who underwent total cystectomy are alive, with a mean survival of 35 months. The 4-year crude survival rate was 50 per cent. Both patients who underwent partial cystectomy died within 2 years. One patient treated with radiotherapy alone and 1 without any treatment have survived 2 years. These results suggest that contrary to the general tendency towards conservative treatment, a curative operation is worth attempting in elderly patients with bladder carcinoma.

Adenocarcinoma↗
PubMed1985

Orally administered methionine alters the growth of tooth germs in newborn rats.

The effects of methionine intubation via gastric needle on the growth of incisor and molar tooth germs in newborn rats were investigated. Upon delivery, the pups were divided into groups of 8 and randomly assigned to dams which were then randomly assigned to three groups. Then the pups were intubated in the stomach with (a) no methionine - group I, (b) 0.1 g methionine per 100 g body weight - group II, or (c) 0.2 g methionine - group III, from day 3 to day 13 on every other day. At day 15, the average body weights of pups among the three groups showed no difference statistically, though animals in group III showed a 17.5% mortality rate; there were no deaths in the other two groups. There was inadequate hair growth in some pups in group III. The weights of incisor and of molar tooth germs in group II were heavier than in groups I and III. The total hydroxyproline content of incisor tooth germs in group II was also greater than in the other groups, whereas there was no difference in molar tooth germs on this parameter among all groups. Collagen synthesis of both tooth germs was highest in group III compared to other groups. The total amount of calcium in both tooth germs showed no difference among groups, but values were consistently higher in group II. 45Ca uptake showed no difference among groups. The present results indicate that the amount of methionine received by growing pups alters the composition of developing tooth germs, but that incisor and molar tooth germs are affected differently.

Administration, Oral↗