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Biomedical subjects

Y Sakuma

Publications and source records attributed to Y Sakuma.

At least 181 records · Page 10Linked to original sources
PubMed1987

[Evaluation of preoperative bladder tumor staging].

Twenty-eight out of 90 patients with bladder tumor seen from 1979 to 1982 were examined by CT, pelvic angiography, cystography and bimanual digital palpation for staging diagnosis preoperatively. Twenty-two patients underwent total cystectomy, and the other 6 patients underwent partial cystectomy. Preoperative staging (T) and postoperative histopathological staging (pT) were compared to define the diagnostic accuracy. The accuracy rate with CT was 20.0%, that with pelvic angiography, 29.4%, that with cystography 33.3%, and that with bimanual digital palpation 47.1%. Digital palpation had a better diagnostic accuracy rather than other examinations.

Aged↗
PubMed1986

Projections of oestrogen-sensitive neurones from the ventromedial hypothalamic nucleus of the female rat.

Stimulation of the mesencephalic central grey matter caused antidromic activation of 199 neurones in the hypothalamic ventromedial nucleus of forty-six urethane-anaesthetized female rats, of which twenty-two (ten ovariectomized and twelve ovariectomized and oestrogen treated) had the lateral projection of the nucleus disrupted by a small parasagittal knife-cut. The remaining twenty-four rats (ten ovariectomized and fourteen ovariectomized and oestrogen treated) had a cut in the frontal plane to interrupt caudal projection of the nucleus. In eight animals with the lateral knife-cut, eighteen cells were antidromically activated from the central grey matter as well as from the dorsal longitudinal fascicle. Collision between the potentials activated from these two sites revealed that seventeen of them descended to the central grey matter by way of the periventricular system, one cell having a bifurcated axon to these sites. Likewise, eleven cells in another group of eight animals with the posterior cut were found to project to the central grey matter via the perifornical region. Pre-treatment with oestrogen significantly lowered the activation thresholds and absolute refractory periods of neurones antidromically stimulated from the central grey in ovariectomized animals bearing posterior but not lateral knife-cuts. These results suggest that the ventromedial hypothalamic neurones responsible for oestrogen-dependent autonomic and behavioural functions project to the central grey via a lateral rather than a posterior pathway.

Action Potentials↗
PubMed1985

Estrogen excites oxytocinergic, but not vasopressinergic cells in the paraventricular nucleus of female rat hypothalamus.

Extracellular antidromic potentials were recorded from the paraventricular nucleus of the ovariectomized female rat hypothalamus following electrical stimulation of the neurohypophysis. Effects of estrogen-treatment were investigated after classifying the antidromically identified cells into tonically-firing, phasically-firing, or silent groups according to their patterns of spontaneous discharge. Estrogen significantly decreased the antidromic activation threshold and shortened the refractory period as well as the antidromic spike latency in the tonic-firing cells. We suggest that estrogen selectively and directly excited the tonically-firing, presumably oxytocinergic cells.

Animals↗
PubMed1985

Gonadal steroid actions on the paraventricular magnocellular neurosecretory cells of the male rat.

One-hundred and ten paraventricular (PV) neurosecretory cells were identified antidromically in castrated male rats anesthetized with urethane. After classifying the antidromically driven units into tonically and phasically firing groups, the latency, threshold, relative refractory period and wave form of the antidromic response were studied. Estradiol and testosterone had no effect on these parameters or on the wave form of antidromic responses in both cell groups. Testosterone caused a significant acceleration of the mean firing rate of the tonically firing cells (from 2.9 +/- 0.6 to 5.1 +/- 0.5 Hz) but estradiol did not affect it. These observations suggest that testosterone modulates the basal firing activity of the tonically firing PV neurosecretory cells in the male rat.

Animals↗
PubMed1985

Antidromic responses in the paraventricular magnocellular neurons of the rat hypothalamus: latency variations correlated with the firing rate.

Magnocellular neurosecretory cells were antidromically identified in the hypothalamic paraventricular nucleus (PVN) of urethane-anesthetized, ovariectomized female rats following electrical stimulation of the neurohypophysis. Seventy-one cells with a tonic pattern of spontaneous discharge were distinguished and used to examine the relationships between the measures of antidromic spike latency, activation threshold and discharge rate. The discharge rate was artificially modulated by either microiontophoresis of glutamate or antidromic stimulation of the neurohypophysis. In all the PVN cells with tonic activity, the latency lengthened and the threshold increased as a function of the discharge rate. Activation of individual cells by microiontophoresis of glutamate was effective, as was simultaneous activation of many PVN cells by antidromic stimulus. Similar relationships between the discharge rate and the parameters of antidromic activation were seen in 3 cells, when their rates varied spontaneously over a wide range without manipulation. These data suggest that the excitability of axons of presumed oxytocinergic cells in the PVN-neurohypophyseal system are influenced by their prior activity, probably through metabolic changes in individual axons.

Animals↗
PubMed1985

[Implant operation of penile inflatable prosthesis for a patient with erectile impotence due to radical cystectomy: a case report].

The hydraulically inflatable penile prosthesis consists of an inflate-deflate pump, a storage reservoir and paired cylinders and it is able to provided a more physiologically functional penis. We report our surgical experience of implant of an inflatable penile prosthesis for postoperative impotence. The patient was a 51-year-old male with impotence, who had received radical cystectomy and ilial conduit formation for transitional cell carcinoma of the bladder (G3, pT3NoMo.) 9 months earlier. There was nothing particular except for the postoperative status on physical, laboratory and X-ray examinations. He was diagnosed to have organic impotence (vasculogenic) by sexual functional tests. Auto-injection of the corpus cavernosum with papaverine HCl was attempted but an erection was not induced by the injection. So, implant operation of an inflatable penile prosthesis was performed by the lower abdominal approach. His postoperative course was uneventable and practice to deflate and inflate the cylinders was started at 2 weeks after the operation and he was able to have sexual intercourse at 5 weeks after the surgery. Now (3 months after the operation), he can have sexual intercourse with an orgasm but without ejaculation and he and his wife are both satisfied with the postoperative status.

Carcinoma, Transitional Cell↗
PubMed1985

Effect of aspoxicillin on anaerobic bacteria.

Aspoxicillin (ASPC), a semisynthetic penicillin has a broad spectrum of antibacterial activities against Gram-positive and Gram-negative anaerobic bacteria. Its in vitro antibacterial activity was less than those of cefoxitin against Peptostreptococcus and Veillonella, but was significantly high against Bacteroides fragilis, one of the most clinically important anaerobe. The therapeutic and/or protective effect of ASPC in experimental subcutaneous abscess or experimental intraabdominal mixed infection due to beta-lactamase producing B. fragilis and non-producing Escherichia coli were much stronger than those of ticarcillin. In order to account the superiority of ASPC in vivo, the effects of ASPC and other beta-lactams on B. fragilis were compared and the results were analyzed in relation to their in vitro bactericidal activities, stability against the beta-lactamase, binding properties with penicillin-binding proteins and pharmacokinetic properties. Interestingly, administration of ASPC did not increase the bacterial counts of Clostridium difficile in caecal contents, but piperacillin, ticalcillin, carbenicillin, ampicillin and cefotaxime increased the counts.

Amoxicillin↗
PubMed1985

[Evaluation of neurogenic bladder in patients with spinal cord injury using a CMG.EMG study and CMG.UFM.EMG study].

Simultaneous recording of intravesical pressure, sphincter electromyography and uroflowmetry (CMG.UFM.EMG study) was performed following cystometry simultaneously with electromyography (CMG.EMG study) on 20 patients with spinal cord injuries. Differences in the influence to micturition between the CMG.EMG study and CMG.UFM.EMG study is thought to be due to whether the catheter is indwelling in the urethra or not. We examined those differences and patient's rehabilitation maneuver (Cred'e maneuver). Micturition pressure and opening pressure measured by the CMG.EMG study were larger than that measured by the CMG.UFM.EMG study (P less than 0.05, P less than 0.01 respectively). Incidence of detrusor-sphincter dyssynergia measured by the CMG.EMG study was greater than that measured by the CMG.UFM.EMG study in the detrusor hyperreflexic cases. The Cred'e maneuver caused increase in opening pressure, micturition pressure and peak flow rate, but the voiding volume and voiding time did not increase to any effective extent. The Cred'e maneuver exaggerated the detrusor sphincter dyssynergia.

Adult↗