Biomedical subjects
Publications and source records attributed to T Nakada.
We report on an infant with terminal deletion of 10q (del10q26.11) presenting with bilateral cryptorchidism. Of 9 males previously reported with terminal deletion of 10q, 1 had an intersex phenotype, and the others all had combinations of cryptorchidism, micropenis, and hypospadias. Terminal deletion of 10q appears to include some genes indispensable for normal male genital development.
Novelty detection is a fundamental capacity of all mammalian nervous systems /64/. The ability to orient to unexpected events is critical for both survival and normal memory function /82/. The mechanisms whereby the brain detects and responds to novelty have become of increasing interest to neuroscientists. A review is provided of human electrophysiological and blood flow data focused on delineating the neural systems engaged by novelty. Electrophysiological recording of event-related potentials (ERPs) has shown that novel stimuli activate a distributed network involving prefrontal and posterior association cortex as well as the hippocampus /4,23,24,32,33,36,86,88/. Activation of this network facilitates subsequent memory for novel events /27/. Neural modeling provides additional support for a prominent role of novelty in normal memory function /43/. Blood flow studies employing PET and fMRI have also begun to define the neural regions activated by novelty. The blood flow data provide converging evidence on the role of the hippocampus and cortical association regions in the processing of novelty /30,66,75,76/. The results of the behavioral, ERP and blood flow research confirm that a distributed neocortical-limbic circuit is activated by stimulus novelty. These distributed circuits maintain a template of the recent past /74/. Deviations from the template activate a neocortical-limbic network facilitating behavioral response to and memory storage of novel events.
Because of the high signal-to-noise (S/N) ratio, T2-weighted images obtained using high-field magnetic resonance (MR) imaging systems can be expected to provide high anatomical and contrast resolution. Furthermore, the improved structural and contrast resolution of these high S/N T2-weighted images can be processed for optimum perceptual resolution through the application of gray-scale reversal and expansion of the gray-scale window, known as T2-reversed (T2R) imaging. In this study, the authors investigated high-resolution T2R MR imaging performed on a high-field (3-tesla) system for its clinical utility in detecting various physiological and pathological conditions.
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PURPOSE: The measurement of prostate specific antigen (PSA) is widely used in screening programs for early detection of prostate cancer. It has been recently shown that the ratio of free-to-total PSA in serum is lower in malignant than in nonmalignant prostatic disorders and, therefore, might be a parameter to improve screening specificity. We determine the influence of renal failure on serum levels of total and free PSA, and free-to-total PSA ratio. MATERIALS AND METHODS: Serum concentrations of total and free PSA, and free-to-total PSA ratio were measured in 93 men undergoing hemodialysis. The control group consisted of 2,298 healthy blood donors. RESULTS: Serum levels of total PSA were not significantly different between control and hemodialysis patients. Serum free PSA and free-to-total PSA ratio of hemodialysis patients were significantly higher than those of controls (p <0.01 to 0.001). However, these values did not change in uremic patients after hemodialysis. Although serum total and free PSA levels increased with each decade of age, they did not correlate with age in hemodialysis patients. CONCLUSIONS: Serum free PSA as well as total PSA is not eliminated by hemodialysis, and elevated levels of free PSA and free-to-total PSA ratio in hemodialysis patients may be caused by a concomitant decrease in binding proteins. The reference ranges for total and free PSA, and free-to-total PSA ratio may not be necessarily beneficial in hemodialysis patients.
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Explore the source record for details and available documents.
BACKGROUND: Although alpha-adrenergic blockers are widely used as a treatment of benign prostatic hyperplasia (BPH), it is not clear whether contractile property of hyperplastic prostate to alpha-adrenergic agonist depends upon an area of density of smooth muscle within the respective BPH tissue. METHODS: Functional study and quantitative morphometric analysis were performed on human prostatic specimens obtained by transurethral resection from 22 men with symptomatic BPH. Tissue norepinephrine content was also evaluated. RESULTS: There was a linear correlation between the area of density of smooth muscle and maximum response to phenylephrine (r = 0.457, P = 0.0362). Although the area of density of smooth muscle showed a positive correlation with norepinephrine content (r = 0.437, P = 0.0471), norepinephrine content was not correlated with maximum phenylephrine response. CONCLUSIONS: Contractile response to alpha-adrenergic agonist was directly influenced by the area of density of the smooth muscle within an individual prostate.
The gene encoding trehalose synthase (catalyzing the conversion of maltose into alpha, alpha-trehalose by transglucosylation) was cloned from Thermus aquaticus ATCC33923. Sequence analysis revealed a 2892 bp synthase gene and a 963 residue amino-acid sequence. The 547 N-terminal residues were homologous to the full-length synthase from Pimelobacter sp. R48 (53.8% identity).
Alveolar fluid clearance was studied in the resected lung of a 58-year-old man who had undergone exploratory thoracotomy 9 days earlier. An isosmolar albumin solution was instilled into the distal air spaces, and the albumin and electrolyte concentrations were measured over 4 h. Alveolar sodium and fluid clearance had increased by nearly 200% from the control values in the resected lungs of patients without prior thoracotomy (n = 5), and histological examination showed that the number of alveolar type II epithelial cells was markedly elevated. These results suggest that an increase in the number of alveolar type II cells may accelerate alveolar fluid clearance under certain clinical conditions.
Erythrocytosis represents a common complication in renal allograft recipients. Traditional therapies including phlebotomy and bilateral native nephrectomies are cumbersome for both the clinical personnel and the patient. Recently, pharmacological agents such as angiotensin converting enzyme inhibitor and theophylline have been proposed as effective therapies for post-transplant erythrocytosis (PTE). We have treated a PTE patient successfully with enalapril without any side effects and renal dysfunction after theophylline treatment showed no improvement in PTE. A decline in Ht levels was independent of the changes in Epo levels during enalapril treatment. Although the mechanism underlying the beneficial effect of enalapril remains undetermined, enalapril is recommended for the initial treatment of PTE.
In order to evaluate the acute effects of two different treatments on changes in the American Urological Association symptom score, we divided 23 men with benign prostatic hyperplasia into 2 groups. Group 1 (n = 16) and group 2 (n = 7) were treated with transurethral resection of the prostate and visual laser ablation of the prostate, respectively. Twice before and about 1 week after surgery, patients completed the AUA symptom questionnaire and underwent urodynamic evaluation. The symptom indexes were subcategorized as obstructive and irritative symptoms. All symptom scores were identical in groups 1 and 2 preoperatively. Postoperatively, significant improvement was found in obstructive scores, the total score, maximum and average flow rates only in group 1. This outcome is probably the reflection of an essential dissmilarity in both therapies. Clinically, the obstructive subscore appears reactive to changes in obstruction and seems meaningful in follow-up even in the early postoperative days.
To see the effect of the alpha-adrenergic blocking agent on tissue norepinephrine contents of the prostate, norepinephrine (NE) levels were investigated in patients with symptomatic benign prostatic hyperplasia (BPH). Morphometrical analyses were also performed to detect the differences in tissue composition. Nineteen patients were subdivided into two groups. Patients in Group 1 were given tamsulosin hydrochloride (0.2 mg/day) for at least 4 weeks before transurethral resection of the prostate (TURP), while patients in the control group (Group 2) underwent no previous treatment for BPH before TURP. Tissue NE contents were investigated by high performance liquid chromatography on a chip of the prostate obtained by TURP. These two groups were closely similar in age distribution, prostatic size, results of preoperative symptom scoring and relative proportion of smooth muscle component within the evaluated specimen. In the present series, tissue NE contents in these groups were not statistically different (p = 0.64). Chronic and acute administration of the alpha-1 antagonist did not apparently influence the tissue NE level in patients with BPH.
Urinary calculus is rarely seen in the urethra and is usually encountered in men with urethral stricture or diverticulum. Primary urethral calculi are extremely rare in females. We describe a case of a giant urethral stone impacted in the urethra of a 103-year-old female.
Urinary bladder sensation to ice water instillation was evaluated in 32 patients with diabetes mellitus. Sixteen patients were urodynamically normal (group 1) and the remaining 16 were diagnosed as having diabetic cystopathy (group 2). Eleven out of 16 patients in group 2 could be considered as having impairment of sensation to urinate. Two out of 16 (12.5%) subjects in group 1 could not perceive ice water infusion, whereas 25% of patients in group 2 did not feel the ice water sensation. In group 2, patients with impaired urinary sensation showed relatively high incidence of negative ice water test (36.4%), although there were no statistical differences between the other groups. There was no apparent relationship between prevalence of peripheral neuropathy and that of negative ice water test. Impairment of ice water perception was less frequent than that of mechanoreceptor sensation in patients with diabetic cystopathy.
PURPOSE: In the mouse, mature oocytes that have been injected with spermatid nuclei failed to become activated. Additional stimulation is required to trigger activation of the oocytes that leads to embryo development. This study was performed to determine whether simultaneous injection of mouse round spermatids and hamster oscillogen can fertilize oocytes and contribute to normal embryo development. MATERIALS AND METHODS: We simultaneously injected mouse oocytes with mouse round spermatid nuclei and a preparation of oocyte-activating protein (oscillogen) from hamster spermatozoa and compared the results with those of injection of testicular spermatozoa. RESULTS: The incidence of normal fertilization and embryo development after simultaneous injection of round spermatid nuclei and hamster oscillogen was not significantly different from that after the injection of testicular spermatozoa. Moreover, the rate of development of two-cell embryos to term did not differ very much between the two groups of oocytes. CONCLUSIONS: Simultaneous injection of round spermatid nuclei and oscillogen appears to be an ideal method for successful activation of oocytes by spermatid nuclei in vitro.
Testicular function in stepwise-nephrectomized rats, with a different interval between the two operations, was studied suing male Wistar rats. Serum levels of urea nitrogen and creatinine in stepwise-nephrectomized rats were significantly elevated compared to those in sham-operated rats (p < 0.001). With a 1-day interval between the two operations, these concentrations were considerably higher (p < 0.001) than those in 7-day interval rats. While serum LH levels were significantly reduced (p < 0.001) in 1-day interval rats, FSH levels in this group were considerably higher (p < 0.001) than in other groups. Serum concentrations of androstenedione in 1-day interval rats were significantly suppressed compared to other groups (p < 0.01). Serum testosterone levels in stepwise-nephrectomized rats were considerably lower (p < 0.001) than in sham-operated rats. It is assumed that testicular function in stepwise-nephrectomized rats is influenced by the interval between the two operations.