Biomedical subjects
Publications and source records attributed to K Shimoda.
A 37-year-old woman with diagnosis of thalassemia intermedia was admitted because of mild dyspnea and edema of her lower extremities. CT scan revealed solid soft tissue masses with a well-defined anterior border, located at the costovertebral angles bilaterally. EH was diagnosed without further investigation and a biopsy was avoided.
Adrenocortical stimulation with ACTH both in the morning (M-test) and in the evening (E-test) and the dexamethasone suppression test were carried out in patients suffering from endogenous depression (DEP) and normal controls (NOR). A greater cortisol release in DEP was recognized than in NOR in the M-test, an earlier peak response of DEP was shown in the M-test than in the E-test, and a lack of association between hypersecretion of cortisol during depression and cortisol output after ACTH administration was noted. These findings, together with the results of DST, suggest that excessive activity of the hypothalamic-pituitary-adrenal (HPA) axis in depression may result, partly, from adrenocortical hyperresponsiveness.
An "organ function index" (OFI) predicting the risk of operative mortality was presented. OFI was estimated on the basis of dysfunction of the systemic organs in patients with esophageal cancer. The pulmonary, cardiac, hepatic and renal functions were assessed by 23 parameters in 108 patients when they were admitted. Operative death was defined as death due to operative complications occurring within 120 days after esophagectomy or by-pass operation. For a discriminant analysis, patients were limited to those in the early period (from October 1981 until December 1985) when the incidence of operative mortality was relatively higher and the parameters were also limited to statistically evaluable ones. Then, a discriminant analysis was performed using data on 18 parameters of four organs in 35 patients each of whom had no deficit in these data. Operative death occurred in 8 out of these 35 patients. Based on the data, an equation to calculate OFI was generated. It consisted of 7 parameters regarding pulmonary, hepatic and renal functions. The values of OFI less than zero predicted no operative death while those more than zero did predict operative death. The prediction rate on presence or absence of operative mortality by this equation was 91.4% in 35 patients. For clinical application, the predictable risk of operative mortality based on OFI was classified as high (OFI less than 1.4), intermediate (0 less than OFI less than 1.4), or low (OFI less than 0).(ABSTRACT TRUNCATED AT 250 WORDS)
The purpose of this study was to assess the effects of chronic insulin infusion on blood pressure and urinary sodium excretion in Wistar rats. Fifteen Male Wistar rats weighing about 220 g were used. The rats were housed in metabolic cage and measured urine volume. Osmotic minipumps filled with insulin (0.57 U/day, Insulin group, n = 9) or saline (0.014 cc/day, Control group, n = 6) were implanted subcutaneously under ether anaesthesia, and blood pressure, urine volume, urinary sodium excretion (UNaV), plasma renin activity (PRA), plasma norepinephrine concentration (PNE) were measured for 4 weeks. In insulin group, there were no significant changes on plasma glucose levels, but systolic blood pressure rose significantly from 119 mmHg to 140 mmHg after 4 weeks. In this group, urine volume, UNaV, and PRA were significantly lower than those of control group and PNE was tended higher but not significant (P less than 0.1). Exogenous NE was given intravenously to assess the endogenous NE activity. Blood pressure elevation caused by exogenous NE in insulin group was suppressed significantly than that of control group. On the basis of these findings, we conclude that insulin can cause high blood pressure due to sodium retention and activation of endogenous NE.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The period of free-running rhythm was measured with two different devices, Automex and running wheel, in blinded female rats. The period was significantly shorter when measured with a running wheel than with an Automex. After transfer between the two devices, all 13 rats examined showed the same direction of change in the free-running period and that transfer from the Automex to running wheel shortened the period, while transfer from the running wheel to Automex elongated it, with the exception of two rats who did not show any significant change in the period even when they were transferred twice. These results indicate that free access to a running wheel shortens the free-running period in female blinded rats.
The effect of chronic administration of the clinically effective antidepressants, imipramine, clomipramine and desipramine, on corticosterone (CS) release in male rats was investigated. Chronic administration of imipramine, clomipramine and desipramine at a dose of 20 mg/kg b.w./day, but not at a dose of 2 mg/kg b.w./day, suppressed blood CS concentration at 2000h and abolished its circadian rhythm. The normal circadian rhythm of CS release resumed seven days after the termination of imipramine injection. The acute administration of imipramine (20 mg/kg b.w./day) at 0800h but not at 2000h elevated CS concentrations. Chronic administration of imipramine (20 mg/kg b.w./day) tended to increase the inhibitory effect of dexamethasone on CS release. Adrenocortical sensitivity to exogenous adrenocorticotropic hormone tended to be decreased by chronic administration of imipramine (20 mg/kg b.w./day). These results indicate that antidepressants have effects on the hypothalamo-pituitary-adrenocortical axis which may confound psychoneuroendocrinological tests, such as the dexamethasone suppression test, for the diagnosis of affective disorders.
The characteristics of motor function and brain dopamine (DA) metabolism in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice after immersion immobilization stress were investigated. There was no significant difference in locomotor activities between MPTP-treated and saline-treated mice, but locomotor activities of MPTP-treated mice after stress decreased more remarkably than those of saline-treated mice. Immediately after stress, striatal DA concentrations of MPTP-treated mice were significantly lower than those of saline-treated mice. Striatal DA levels improved when 24 h passed after stress. The striatal and cortical (DOPAC + HVA)/DA ratios of MPTP-and stress-treated mice was significantly higher than that of saline-and stress-treated mice. It is due to the decreased DA level and the enhancement of DA turnover that MPTP-treated mice became remarkably akinetic after stress, and that L-DOPA therapy is not effective when the symptoms in patients with Parkinson's disease worsen due to stress.
Analysis of biopsies of cervical intraepithelial neoplasia (CIN) revealed a high percentage of human papillomavirus (HPV) sequences that would hybridize to a mixture of HPV probes only under conditions of relaxed stringency. The DNA sequences of one of these viruses was molecularly cloned and shown to be a new HPV, type 52 (HPV-52). This virus is most closely related to HPV-33. Hybridization analysis with restriction fragments of HPV-52 showed collinearity with the HPV-33 genome. DNA sequencing revealed a high level of conservation between the two viruses within the L1 open reading frame but significant divergence in the non-coding region of the viral genomes. Prevalence studies indicated that HPV-52 sequences were present in three of 137 (2%) CIN and in one of 48 (2%) cervical squamous cell cancers studied in the U.S.A.
A "host defense index" (HDI) has been developed that predicts the risk of operative mortality based on the impairment of host defense in patients with esophageal cancer. The function of host defense was assessed on admission in 32 patients. Assessment included 21 parameters of nutritional status, cellular immunity, humoral immunity, neutrophil levels, complement levels and serum factors. Operative deaths, which were defined as deaths due to operative complications occurring within 120 days after esophagectomy or by-pass operation, were in 10 out of 32 patients. A discriminant analysis was then performed using 21 parameters in 32 patients, and an equation to calculate HDI was generated. The equation consisted of 10 parameters. The values of HDI more than -0.90 predicted no operative deaths while those less than -0.90 did predict operative deaths. The percentage of patients correctly classified was 87.5%. For clinical application, the predictive risk of operative mortality based on HDI was classified as high (HDI less than or equal to -1.80), intermediate (-1.80 less than HDI less than 0) or low (HDI greater than or equal to 0). The values of HDI in 32 patients were compared with those of the prognostic nutritional index or nutritional assessment index but no significant correlation between HDI and those indices was recognized.
The primary structures of porcine and human pancreatic elastase II precursors were elucidated by molecular cloning and cDNA sequence analysis. The sequences of the cDNAs cloned from a human pancreatic cDNA library indicate that at least two elastases II are expressed in this tissue. These two human elastases II have been designated elastases IIA and IIB. All the cDNA sequences obtained, including porcine elastase II cDNA, reveal that elastase II is synthesized as a preproenzyme of 269 amino acids, including a predicted signal peptide of 16 amino acids and a predicted activation peptide of 12 amino acids. Human elastase IIA contains the published amino-terminal sequence (16 residues) for human pancreatic proelastase II, whereas elastase IIB shares 50% homology with the published 16-residue sequence. However, there is 90% homology between the overall amino acid sequences of elastases IIA and IIB. Blot hybridization analysis of the poly-adenylated RNAs isolated from various human tissues demonstrates that the human elastase II mRNAs are specifically detected in the pancreas.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Drinking rhythm in 6 rats optically enucleated on the day of birth was determined every one to two weeks after weaning until the age of 28 weeks. Each rat was transferred repeatedly from a cage without a running wheel to one with a running wheel, and vice versa. During the periods when the rats were housed in the former cage, drinking rhythm delayed, while it advanced when they were housed in the latter. The rats, which had a period of free-running rhythm of motor activity longer than 24 hr when measured by an Automex device in a cage without a running wheel, showed a period shorter than 24 hr when measured by a running wheel. These results suggest that the difference in tools for determination of activity may influence the results of animal experiments for free-running rhythm, and warn investigators of risks being caused by the selection of tools.
To study the possibility and potency of periodic maternal deprivation (PMD) in entraining the circadian rhythm of rat pups, access to the natural mother of which pups were optically enucleated on the day of birth (day 1) was restricted to either light phase (L-group) or dark phase (D-group) for various durations beginning on various days during the nursing period. Drinking rhythm of both groups was determined once per one or two weeks between the 4th and 8th postnatal week. The corticosterone rhythm was determined to confirm the results obtained by the measurement of water intake. Both rhythms were clearly observed by 5 weeks of age, and a reversed phase relationship was observed even when PMD was performed for a short period during days 1-4 or days 15-21. On the other hand, no phase angle difference was observed between L- and D-groups, when pups were periodically exposed to their original mother either during days 1-2 or days 18-21. These facts indicate that periodic exposure to mother can set the phase of the blinded pups' rhythm and that the period required for entrainment of the rhythm is as short as 4 or 7 days in the early or late times during the nursing period respectively, showing the high potency of PMD in entraining the circadian rhythm of blinded pups.
For further investigation of the role of rat dams in setting the phase of pups' endogenous circadian rhythm, periodic maternal deprivation experiments were performed. Access of intact original mothers to blinded pups was restricted to light phase (L-Suckling pups) or dark phase (D-suckling pups) under 12-12 h light-dark alternation throughout the nursing period. Free-running patterns of drinking and corticosterone rhythms were determined for 3 consecutive weeks after weaning. In each determination of the rhythm, water consumption and corticosterone levels were measured every 4 hr. Both rhythms were clearly observed in both L- and D-suckling pups. Acrophase of water intake rhythm at 5 weeks of age in L-suckling and D-suckling groups were 0758 h and 1954 h while those of corticosterone rhythm were 0143 h and 0948 h respectively. Reversed phase relationship of rhythms between L- and D-suckling groups were observed throughout the period examined. These results indicate that suckling can act as a Zeitgeber for the endogenous rhythm of pups.
To investigate the relationship between serotonergic system and development of the circadian rhythm, we made destruction of the dorsal region of midbrain including dorsal raphe nuclei in neonatal rat pups. Overt circadian rhythms of locomotor activity and water consumption were clearly observed at 4-6 weeks of age, in both the sham operated and the lesioned pups. However, amount of both activities in the lesioned pups was significantly larger than that of the sham operated pups during the light phase. This indicates that the circadian activity rhythm is altered by the lesion, although the degree of alteration is slight. This suggests the involvement of the serotonergic system in the full development of the normal circadian rhythm. An irregular drinking pattern was observed in the lesioned rats at 5 months of age, although a light-dark difference in water consumption was evident. It takes longer for lesioned adult rats to manifest a significant day-night difference in water consumption, than for sham operated rats after reversal of light-dark cycle. This suggests that a lesion in the dorsal midbrain made during the neonatal period may cause a permanent change in the circadian system.