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Biomedical subjects

T Nakamoto

Publications and source records attributed to T Nakamoto.

At least 181 records · Page 10Linked to original sources
PubMed1985

Effects of oral caffeine intubation on bones in protein-energy malnourished newborn rats.

Lactating dams with 8 suckling pups were fed either a 6% or a 20% protein diet from the birth of the pups to day 15. The pups were divided into caffeine and noncaffeine groups. Every other day between days 3 and 13, pups were either intubated with caffeine (1 mg/100 mg) dissolved in 0.1 ml physiological saline solution, or 0.1 ml saline solution as a control. On day 15, mandible and long bone weights, DNA, protein and calcium contents, collagen synthesis and 45Ca uptake in these bones of the pups were studied. Nutritional factors exercised consistent effects on all the studied parameters, but there was no difference in effects attributable to caffeine intubation, except the increased collagen synthesis in the long bones of the group with 6% protein diet with caffeine as compared to noncaffeine members of the same dietary group. We concluded that the direct administration of a relatively small amount of caffeine to newborns causes minor effects on bone development under certain nutritional conditions.

Animals↗
PubMed1985

Effects of orally administered caffeine on cellular response in protein energy-malnourished neonatal rat brain.

The purpose of this study was to determine the effects of caffeine on growing rats and how protein energy malnutrition can modify these potential effects. Caffeine (1,3,7-trimethylxanthine) is not only the most commonly consumed, neurally active stimulant in our daily lives, but it is widely used in the management of apnea in the premature neonate. One group of dams (20%) (n = 6) was begun on a 20% protein diet ad libitum. The second group (6%) (n = 4) was begun on a 6% protein diet. A third group (20% + C) (n = 4) was pair-fed to group 1 (20%) with the 20% protein diet, but beginning on day 3 the pups received 10 mg/kg body weight of caffeine via intragastric feeding needle every other day. The fourth group (6% + C) (n = 5) was pair-fed with group 2 (6%) with the 6% protein diet and the pups received 10 mg/kg of caffeine in the same manner as the 20% + C group from day 3. Although the 6% protein diet was associated with the expected reduced body and brain growth, there were no additional growth alterations associated with caffeine administration in either the 20% or 6% diet groups. This growth failure was accompanied by the expected reductions in total whole brain DNA, RNA, protein, and cholesterol content regardless of whether caffeine was received or not. Effects of caffeine which were similar in both diet groups included an increase in brain RNA content and concentration and an increase in the RNA/DNA ratio. However, there were differential effects of caffeine seen depending on diet group assignment.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1985

Effects of chronic caffeine ingestion on growth and myocardial function.

Experiments were conducted to determine whether chronic caffeine consumption during early growth and development affected cardiac performance and development of adipose tissue. Dams were fed a nutritionally complete diet with or without the addition of 10 mg/kg caffeine during lactation. After weaning, the pups were maintained on this diet until they were sacrificed at 88 days of age. Body weight at the time of sacrifice was comparable for both groups. The hearts from caffeine-fed animals were significantly (P less than 0.05) larger based on both dry and wet weights although the dry weight/wet weight ratios were similar. Ventricular function curves were generated on each heart using an isolated working heart preparation. The isolated hearts of caffeine-fed rats exhibited a significant reduction in cardiac output, stroke volume, mean aortic pressure, and estimated myocardial work when compared to controls. The rats fed caffeine had greater plasma triglyceride levels with no significant differences in adipocyte size or number in the epididymal and perirenal depots. It is concluded that chronic caffeine intake from birth may alter cardiac function of the offspring.

Adipose Tissue↗
PubMed1985

[A case of pure leiomyoma of the prostate].

A case of pure leiomyoma of the prostate is reported. This disease is very rare and only 10 cases could be collected from the Japanese literature. Our case is the 11th case of this disease in Japan. A 48-year-old man was admitted to our hospital because of urinary retention. Retrograde urethrocystogram showed evidence of protrusion of the left lobe of the prostate. Excretory urogram revealed bilateral hydronephrosis and voiding cystogram revealed VUR on left ureter. Transurethral biopsy suggested benign prostatic tumor. Open resection of the tumor was performed. Histologically, the specimen removed was pure leiomyoma of the prostate. After operative treatment, disturbance of urination and hydronephrosis disappeared.

Humans↗
PubMed1985

Alteration by liquid protein diet of TRH and cyclo(His-Pro) in the young rat brain.

Effects of liquid protein diet (LPD), known to be poor in protein quality, on brain thyrotropin-releasing hormone (TRH) and histidylproline diketopiperazine (cyclo(His-Pro] were examined in young male rats. At day 23 of weaning, the animals were fed either a 20% casein diet ad libitum or a 20% LPD, or were pair-fed with a 20% casein diet. They were decapitated at day 48. The body weight of those in the LPD and pair-fed groups decreased significantly, and the loss was sustained in comparison with that in the ad libitum group. Cyclo(His-Pro) concentrations in the whole brain were significantly greater in the LPD group than in the pair-fed and ad libitum groups, whereas its concentrations were similar in the pair-fed and ad libitum groups. No significant differences were observed in concentrations of brain TRH in the three groups. These findings indicate that quality of the protein component in the diet contributes to alterations in the neuropeptide, cyclo(His-Pro), in the young rat brain.

Animals↗
PubMed1985

[Two cases of primary hyperparathyroidism].

Two cases of primary hyperparathyroidism with urolithiasis are reported. These cases were preoperatively localized by CT-scan and 201T1-chloride scintiscan. Primary hyperparathyroidism is one of the most significant pathogenesis of urolithiasis and determination of serum Ca level is valuable in screening for primary hyperparathyroidism. CT-scan, ultrasonogram and scintiscan with 201T1-chloride are useful and are non-invasive studies to detect preoperative localization of parathyroid tumors.

Adenoma↗
PubMed1984

Protein-energy malnutrition during pregnancy alters caffeine's effect on brain tissue of neonate rats.

We studied whether protein-energy malnutrition changed brain susceptibility to a small dose of caffeine in newborn rats. Since we had demonstrated previously that caffeine intake during lactation increased the brain neuropeptide on newborns, we investigated further the effects of the prenatal administration of caffeine on TRH and cyclo (His-Pro). From day 13 of gestation to delivery day, pregnant rats in one group were fed either a 20% or a 6% protein diet ad libitum, and those in the other group were pair-fed with each protein diet supplemented with caffeine at an effective dose of 2 mg/100 g body weight. Upon delivery, brain weight, brain protein, RNA, DNA and the neuropeptides thyrotropin-releasing hormone (TRH) and cyclo (His-Pro) were measured in the newborn rats. A 6% protein without caffeine diet caused reductions in brain weights and brain protein, RNA and DNA contents, but did not alter brain TRH and cyclo (His-Pro) concentrations in the newborn animals. In the offspring from dams fed a 6% protein diet, caffeine administration significantly elevated brain weights and brain contents of protein, RNA and DNA. In contrast, these values were similar between noncaffeine and caffeine-supplemented animals in a 20% protein diet group. Brain TRH and cyclo (His-Pro) concentrations were not changed by caffeine administration. These data suggest that caffeine augments protein synthesis in the newborn rat brain when malnourished, but that the same dose of caffeine did not affect protein synthesis in brains of newborn rats from normally nourished dams. Therefore, the present findings indicate that the nutritional status of mothers during pregnancy has important implication in the impact of caffeine on their offspring's brains.

Adult↗
PubMed1984

The role of ascorbic acid deficiency in human gingivitis--a new hypothesis.

Periodontal disease is one of the most prevalent health problems in the world and is the major cause of tooth loss in the adult population. Its two major subdivisions are gingivitis where disease is confined to the gingiva, and periodontitis where disease is present both in the gingiva and the supporting periodontal tissues. During the first stage there is a vasculitis of vessels subjacent to the junctional epithelium which is followed by exudation of fluid from the gingival sulcus and migration of leukocytes. There is variable expression of this stage throughout the mouth with new areas of involvement appearing in place of healed areas. Mast cells which are present in the gingival connective tissues may participate in this inflammatory response by liberating histamine. Ascorbic acid deficiency has been shown to be a conditioning factor in the development of gingivitis. When humans are placed on ascorbic acid deficient diets there is increased edema, redness and swelling of the gingiva. These changes have been attributed to deficient collagen production by gingival blood vessels. However, this may be due to an antihistamine role of ascorbic acid. This vitamin may act to directly detoxify histamine or effect a change in the level of enzymes responsible for histamine metabolism. This could occur through the influence of ascorbic acid in altering cyclic AMP (c-AMP) levels. Such changes in the level of this regulatory molecule could result in increased histamine-N-methyl transferase and other enzymes responsible for the breakdown of histamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Theophylline effects on cellular response in protein-energy malnourished neonatal rat brain.

The present study employed an animal model in an attempt to document effects on brain growth of long-term exposure to theophylline in the presence or absence of malnutrition. One group of dams was randomly divided into half. One-half was fed a 20% protein diet and the other half a 6% protein diet. Similarly, a second group of dams was also randomly divided into two groups. These were pair-fed with rats of the first group, receiving diets comparable to those in group one but to which theophylline was added in amounts calculated to provide daily doses of 2 mg/100 g of body weight. Theophylline supplementation in the dams' 6% protein diet decreased the body weight of the pups consistently from d 3 to the end of the study at d 15 in comparison to the non-theophylline group. In contrast, the presence of theophylline in the control diet increased the body weight of the pups at d 15 compared with that of the non-theophylline group. Brain weight was essentially identical in the normal controls and the normally nourished group given theophylline. No difference in brain weight was noted between the malnourished group and the malnourished group given theophylline. We found a significant reduction in DNA content per brain or per mg of brain weight in the normally nourished group given theophylline compared with non-theophylline group. DNA values per mg of brain weight from the controls that received theophylline were not different from either malnourished group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Differential effects of collagen in oral tissues and skin by protein-energy malnourished newborn rats and lactating dams.

Effects of protein-energy malnutrition were studied in newborn rats and their dams. Upon delivery, dams received 6%, 12% or 20% protein diets. At Day 15 pups received 14C(U)-proline. The posterior tongue, hard palatal mucosa, soft palatal mucosa and skin were analyzed for collagen and counts incorporated (collagen synthesis, that is, the rate of 14C-proline converted to 14C-hydroxy-proline into gingival collagen). These regions of the dams were also removed to study collagen content. Although soft palatal mucosal collagen of newborns in the 6% and 12% protein groups was decreased, that of skin in the 6% protein group was increased. No such differences were observed in tongue and hard palatal mucosa. Counts incorporated was decreased in the tongue, soft palatal mucosa and skin, but not in hard palatal mucosa. Collagen contents of tongue and hard palatal mucosa and skin of the dams showed no differences, whereas that of soft palatal mucosa in the 6% protein groups was increased. Effects of protein-energy malnutrition on oral tissues and skin were therefore different between newborns and lactating dams. Furthermore, one part of oral mucosa is affected differently from other parts of mucosa and in both, degree of malnutrition has different influences.

Animals↗
PubMed1984

Effects of caffeine on the growth of mandible and long bone in protein-energy malnourished newborn rats.

Rat dams with eight pups each were divided into six groups upon delivery; the first three were fed 6, 12 or 20% protein diets, and the second three the same diets but with caffeine added in the amount of 2 mg/100 g body wt. At Day 15, randomly selected pups were injected with [14C]proline to determine collagen synthesis of mandible and long bone. Other pups were used to determine the calcium content of these bones. The body, mandibular, and long bone weight of the pups whose dams were fed the 6% protein diet with caffeine increased compared to the noncaffeine group. Calcium content of the mandible and the collagen synthesis of the long bone were also increased. However, calcium content of long bone, collagen synthesis of mandible, and hydroxyproline content of mandible and long bone showed no difference between the caffeine and noncaffeine groups. In the pups whose dams were fed the 12% protein diet with caffeine, body and mandibular weight, collagen synthesis, and hydroxyproline and calcium contents in mandibles and long bones of pups showed no difference from those of the noncaffeine group, but long bones were heavier. In the pups whose dams were fed the 20% protein diet with caffeine, the body and long bone weight and hydroxyproline and calcium contents of the long bone of pups were lower than those of the noncaffeine group. Mandibular weight, calcium content, and hydroxyproline showed no difference between caffeine and noncaffeine animals, but collagen synthesis of the mandible was increased. Current data indicate that nutritional state and caffeine intake of the mother have a close relation to growth and development of the offspring.

Animals↗
PubMed1984

Malnutrition and oxygen at high pressure: influence on collagen synthesis in lung and heart of the newborn rat.

Rat dams were divided into a malnourished group fed 6% protein and a control group fed 25% protein. Newborns were selected from the two groups for injection with 14C-proline. Half of those injected were exposed to oxygen averaging 60 psig. Malnutrition impaired collagen synthesis in the lung as early as day 10 and in the heart at day 5. At day 20 and 30, pups from malnourished dams showed less severe convulsion than did the controls. Malnourished group displayed less adverse effect on lung and heart relative to body weight than did controls. Lung and heart collagen content in the malnourished group at days 15 and 10, respectively, were less than the controls. Between day 5 and day 20, OHP does not affect the metabolism of the lung and heart connective tissues, but it does by day 30. Malnutrition affects collagen metabolism of the heart earlier than it does the lung.

Animals↗
PubMed1983

Protein-energy malnutrition alters brain thyrotropin-releasing hormone and cyclo (His-Pro) in the neonatal rat.

To evaluate effects of protein-energy malnutrition on the brain neuropeptides thyrotropin-releasing hormone (TRH) and cyclo (His-Pro) in the cerebellum and the remainder brain, we studied neonatal rats in the lactational period. Protein-energy malnutrition caused an increase in cyclo (His-Pro) concentrations, but not in TRH concentrations, in the neonatal cerebellum. In the remainder brain, a reduction in cyclo (His-Pro) concentrations occurred with an increase in TRH concentrations. These data indicate that protein-energy malnutrition affects both brain TRH and cyclo (His-Pro) in the neonatal rats during lactation.

Animals↗
PubMed1983

Influences of maternal caffeine on the neonatal rat brains vary with the nutritional states.

The potential effect of maternal caffeine ingestion upon total brain protein and the concentration of two prototype neuropeptides, thyrotropin-releasing hormone (TRH) and its derivative, cyclo (His-Pro) in neonates was examined during the nursing period in the context of variable maternal protein intake. Maternal caffeine intake (2 mg/100 g body weight) significantly increased the total brain protein of neonates derived from dams fed a 6% casein diet, but not from dams fed a 12%- or 20%-casein diet. Maternal caffeine consumption significantly increased the amount of cyclo (His-Pro) in the neonatal brains in all groups. The percent increments in pups from dams fed 6%, 12%, and 20% casein diets were respectively 137%, 131%, and 120%. By contrast, no significant alterations were observed in TRH concentrations between caffeine and control groups. It is concluded that maternal caffeine can influence neonatal brain protein and cyclo (His-Pro) during nursing under conditions of protein-energy malnutrition.

Animals↗
PubMed1983

Brain TRH and Cyclo (His-Pro) and brain protein in the newborn rat are altered by maternal liquid protein feeding.

Liquid protein diet (LPD) has been shown previously to produce maternal and fetal weight loss and fetal congenital anomalies, including cataracts and craniofacial malformations. Therefore, to examine the effects of LPD in pregnancy upon the central nervous system of pups, pregnant dams were fed either a 20% casein diet ad libitum, a 20% LPD, or pair-fed with a 20% casein diet. LPD was associated with significant maternal weight loss, and pups had significantly lower birth weights (5.14 +/- 0.64) than pups from the pair-fed controls (5.70 +/- 0.46, p less than 0.05). Total brain protein content was reduced significantly in pups of both sexes from pregnant fed LPD. Moreover, the concentrations of two brain peptides neurotransmitters, thyrotropin-releasing hormone (TRH), and its biologically active metabolite, histidyl-proline diketopiperazine Cyclo (His-Pro), were elevated in the pups from LPD-fed mothers. In contrast, there was no significant difference in brain protein or brain peptides in pups from pair-fed mothers vs. pups from mothers fed ad libitum. These data suggest that qualitative alterations of the protein component in maternal dietary composition have deleterious effects upon the ontogeny of the rat fetal CNS, as reflected by reduced total protein and elevated concentrations of TRH and Cyclo (His-Pro).

Animals↗