PubMed Health⌕ Search

Biomedical subjects

Z Masaki

Publications and source records attributed to Z Masaki.

At least 37 records · Page 2Linked to original sources
PubMed1994

[The prognostic value of mean nuclear area and mean nuclear volume in bladder cancer].

To evaluate the prognostic value of mean nuclear area (MNA) and mean nuclear volume (MNV) in bladder cancer, a retrospective study was performed comprising 67 bladder cancer patients who could be followed up for more than 3 years. Cosmozone 1SA, a Nikon image analyzing system was used for the morphometric study. The specimen of initially biopsied tumor tissue was set in an Olympus microscope at 400-fold magnification, and the image was superimposed on the monitor picture through a video camera attached to the microscope. MNA and MNV were measured by tracing the contour of the nucleus which were selected by the point-sampled intercept methods. The time required for measurement of the area and volume was about 15 minutes per case. MNA in cases with histological grade 1, 2 and 3 were 35 +/- 3 microns2 (mean +/- SD), 42 +/- 10 microns2 and 62 +/- 12 microns2 respectively. MNV with grade 1, 2 and 3 were 282 +/- 46 microns3, 371 +/- 148 microns3 and 644 +/- 182 microns3 respectively. The morphometric results were significantly related to histological grade. In cases with a value of MNA of 40 microns2 or more and/or a value of MNV of 370 microns3 or more, the proportion of cases who underwent cystectomy or died of cancer was significantly high and demonstrated poor survival. In contrast, those who showed MNA and MNV less than the above value had better prognosis. These results suggest that the measurements of MNV seems to be useful for objectively evaluating the malignant potential of bladder cancer.

Adult↗
PubMed1993

Influence of extracellular matrix on the proliferation and differentiation of adrenocortical cells in culture.

Extracellular matrix is indispensable for cell differentiation in vivo. The aim of this study is to examine effects of extracellular matrix on adrenocortical cells embedded in collagen gel in terms of cellular proliferation and differentiation. Dissociated human or bovine adrenocortical cells were embedded in collagen gel; the gel was then immediately thin-coated on the bottom of culture dishes. The cortical cells were thus trapped in collagen and cultured in monolayer, a suitable means for observation of culture cells. To the authors' best knowledge, this "collagen gel-embedded" monolayer culture is described here for the first time. Cortical cells were spherical in shape and had the activities of proliferation and steroid production in collagen gel matrix of this culture method. Aldosterone production in particular tended to be maintained much longer than in conventional monolayer culture. This method seems to provide a physiological environment in which to study the differentiation of cortical cells.

Adrenal Cortex↗
PubMed1992

In vivo detection by microscopic chromocystoscopy of concurrent urothelial atypia in superficial bladder cancer.

Microendoscopic observation of methylene blue-stained urothelial surfaces, so-called microscopic chromocystoscopy (MCC), was undertaken in 65 patients with superficial bladder cancer (Ta and T1) and its effectiveness in detecting concurrent urothelial dysplasia or carcinoma in situ was studied. A total of 166 biopsy samples were taken from 75 stained and 91 non-stained portions. Of 75 methylene blue-stained areas, 21 were judged to be abnormal (MCC-positive) by microscopic observation. Fourteen of these 21 MCC-positive areas (67%) were proven to be abnormal histologically, while 7 of 54 MCC-negative portions (13%) were histologically abnormal. Only 4 of 91 biopsies (4%) from non-stained mucosa were proven to have urothelial atypia. In per patient figures, 1 or more concurrent field changes were detected in 15 of 65 cases (23%). MCC contributed to the diagnosis in 10 of these 15 patients.

Aged↗
PubMed1992

Patterns of renal function in hypertension due to unilateral renal artery occlusion.

We performed renal function studies in dogs with chronic renovascular hypertension produced by complete occlusion of a renal artery. In addition, we evaluated in anesthetized dogs the acute effects of a novel angiotensin converting enzyme inhibitor, CGS 16,617, on renal function and plasma neurohormones (epinephrine, norepinephrine and vasopressin) 4 weeks after initiation of 2 kidney, 1 clip hypertension. CGS 16,617 effectively decreased blood pressure in renal hypertensive animals. This response was associated with suppression of angiotensin II indicating effective converting enzyme inhibition. In the non-clipped kidney, acute administration of CGS 16,617 increased effective renal plasma flow but not glomerular filtration rate and urinary sodium excretion. In the clipped kidney, CGS 16,617 caused no change in any parameter of renal function. Plasma norepinephrine, epinephrine and vasopressin were unaffected by administration of CGS 16,617. These studies showed that chronic occlusion of a renal artery does not result in renal infarction because of a compensatory increase in the amount of blood provided through capsular collateral vessels. The collateral circulation which has developed in the clipped kidney explains the lack of a converting enzyme inhibitor effect.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1992

["Dismembered spiral flap pyeloplasty" for uretero-pelvic junction obstruction].

We report a new operative technique for plastic correction of uretero-pelvic junction (UPJ) obstruction: dismembered spiral flap pyeloplasty. It is similar to the method described by Culp & DeWeerd in that a flap is made spirally but different in that UPJ is detached. Relatively a long and wide spiral (oblique) flap, the apex of which directs cranioventrally or craniodorsally, is made using the dilated pelvis. The apex of the flap is reflected downward and anastomosed to the split ureteral end. Because the flap is made obliquely, one side of the flap base is approximated to the opposite pelvic margin; this helps to make gradual funnelling of pelvio-ureteric transition. The method seems to be fit for cases with considerably long stenosis of UPJ and with the UPJ locating relatively close to the medial margin of the renal parenchyma. Seven of 26 pyeloplasties were done by this method in our institute, and all the 7 cases had satisfactory results.

Adolescent↗
PubMed1991

Voiding dysfunction in patients with human T-lymphotropic-virus-type-1-associated myelopathy.

Voiding dysfunction in patients with human T-lymphotropic-virus-type-1-associated myelopathy (HAM) was studied. All the patients were diagnosed as having HAM by neurologists. We have already reported on 16 consequent patients with HAM. Almost all of these patients had frequency, and many had urge incontinence of urine and difficulty on voiding. Urodynamic study revealed that their voiding symptoms seemed to be due to detrusor hyperactivity and detrusor-sphincter dyssynergia. However, we have recently treated 2 patients who had a different bladder function. They had both frequency and difficulty in voiding but without urgency. In the urodynamic study both patients did not have involuntary bladder contraction during the filling phase and could not void voluntarily. The reason why these 2 patients had an underactive detrusor is unclear. The fact that the average duration of HAM in the 16 patients previously mentioned was longer than that of the latter 2 patients may suggest that overactivity of the bladder is not prominent in the early phase of this disease.

Female↗
PubMed1991

[Urinary cytology studied during 10 days after transurethral resection of bladder tumour and its relation to tumour recurrence].

Whether or not recurrence is related to the results of urinary cytology examined within 10 days after transurethral resection of bladder tumour was studied retrospectively in 47 patients with superficial bladder tumour. Of 7 cases with positive cytology during the postoperative 10 day period, 4 cases had a later recurrence of tumour and 2 cases had a residual tumour due to incomplete resection of original tumour. By microscopic chromocystoscopy, in 11 patients concurrent urothelial atypia (carcinoma in situ or dysplasia) was found in the apparently normal mucosa. Nine of the 11 cases had a later recurrence of tumour or a residual tumour. Of in total 15 patients combined with abnormal cytology and concurrent urothelial atypia, 12 (80%) were found with recurrence of tumor cystoscopically 4 approximately 64 months (mean; 20.6 months) after TUR. This recurrence rate was significantly (p less than 0.05) higher than that (42.4%) in patients without positive cytology and concurrent urothelial atypia. These results suggest that positive urinary cytology during 10 days subsequent to TUR and/or association with concurrent urothelial atypia are indicative of later tumour recurrence, incomplete resection of tumour or presence of additional occult tumour foci.

Humans↗
PubMed1989

Voiding dysfunction in patients with human T-lymphotropic virus type-1-associated myelopathy (HAM).

Voiding dysfunction was evaluated in 16 of 17 patients with human T-lymphotropic virus type-1 associated myelopathy (HAM). Among 16 patients 11 had both frequency and difficulty in voiding and 12 had urge incontinence of urine. Sensation of vesical filling and voiding remained either intact or only slightly suppressed in all patients. Residual urine ranging from 50 to 320 ml was observed in 14 patients. Urodynamic studies showed in every patient an overactive bladder with involuntary detrusor contraction. Only 2 patients had detrusor sphincter synergia, 6 patients had complete detrusor sphincter dyssynergia and 8 patients had incomplete detrusor sphincter dyssynergia. An overactive bladder associated with detrusor sphincter dyssynergia and less affected vesical sensation seems to be a characteristic urodynamic finding in HAM. These results combined with other neurological findings suggest that in patients with HAM lateral columns of the spinal cord between sacral and ponsmesencephalic micturition centre are mainly affected and that the posterior columns of the spinal cord are relatively less affected.

Adult↗
PubMed1989

[Pseudolymphoma of the bladder: a case report].

We report a 63 year-old female with solid, nonpapillary, and smooth-surfaced bladder tumescence of approximately 30 and 7 mm in diameter. Biopsy of the tumor and other apparently normal epithelium revealed dense lymphocytic infiltrations with formation of many lymph follicles. Because of the relatively large nodular form of the lesion we regarded this to be pseudolymphoma of the bladder rather than follicular cystitis. Pseudolymphoma in the bladder has not yet been reported in English literatures to our knowledge. The tumorous changes have disappeared by 6 months after the initial 3 week chemotherapy.

Biopsy↗
PubMed1988

[High resolution ultrasound examination in the diagnosis of the undescended testis in the inguinal region].

Twenty-six undescended testes in 22 patients between 1 and 31 years old were evaluated with ultrasonographic examination between October, 1981 and December, 1985. All 22 patients were operated on, and the accuracy of the ultrasonic diagnosis was evaluated in comparison to that of palpation diagnosis. Fourteen of 26 testes could be palpated preoperatively and these were all identified ultrasonographically and surgically. Twelve testes could not be palpated. On these 12 testes, surgical exploration revealed 9 testes in the inguinal region and absence of 3 testes. Ultrasound examination predicted its presence in 5 of 9 testes and its absence in all 3 testes. Both sonography and palpation failed to identify their presence in 4 tests. Thus, sensitivity of ultrasound examination was 82.6%, specificity 100% and accuracy 84.6% retrospectively. We conclude that ultrasound examination is useful in diagnosis of impalpable undescended testes in inguinal region.

Adolescent↗
PubMed1985

Intrasinusal pyelocalicotomy with lower pole nephrotomy for removal of renal stones.

A small renal sinus often limits exposure of the intrarenal pelvis and restrains the sinus approach for removal of renal stones. For 14 such cases, we used a lower pole nephrotomy combined with extended pyelolithotomy. Incision of the renal parenchyma through the intersegmental avascular plane greatly facilitated exposure of the intrarenal collecting system and enabled stone removal through the longitudinal incision of the collecting system. The indication for operative technique and results of the procedure are described.

Humans↗
PubMed1982

Postoperative prophylactic intravesical instillation of cytosine arabinoside and mitomycin C in superficial bladder tumor. A follow-up study.

A follow-up study was made on 225 Japanese patients with superficial bladder tumors who were treated postoperatively with intravesical instillation of cytosine arabinoside and mitomycin C nineteen times during one year. Cumulative recurrence rates of the tumor were 16.7 and 41.9 per cent during the first 1 and 3.5 years after surgery, respectively. These results are superior to the previous findings in cases in which instillation therapy was not given. Histologically, there was no definite difference in recurrence among the groups with low-grade and high-grade tumors. The recurrence rate of multiple tumors was higher than that of a solitary tumor. Earlier postoperative instillation appeared to be more effective during the initial one year after surgery.

Adult↗
PubMed1982

Bilateral renal artery stenosis and renovascular hypertension in rabbits.

In 21 rabbits bilateral renal artery stenosis was produced by constriction of the right renal artery with 1 of 3 different clips in size followed by left renal artery constriction with the smallest clip. Five to 6 weeks after left renal artery constriction, 5 ml. of the blood samples for the measurement of plasma renin activity (PRA) was taken from both renal veins and the distal vena cava, and the left nephrectomy was performed. In 17 out of 21 rabbits, PRA was determined in 3 different blood veins: L, left renal vein PRA; R, right renal vein PRA; and P, distal vena cava vein PRA. Three PRA patterns, L greater than P greater than or equal to R (A type), L, R greater than P (B type) and R greater than L not equal to P (C type), were observed. Removal of the left kidney caused a significant decrease in the average blood pressure persisting for 5 weeks in the rabbits with the type A pattern of PRA (p less than 0.05). In all 4 animals with the type B or C pattern of PRA hypertension persisted even after removal of the left kidney. Comparison of the PRA values between the venous blood in 3 different vascular trees seems very useful to predict the depressor response that follows nephrectomy of the severer constricted side.

Animals↗
PubMed1981

Neurogenic suppression of carotid sinus reflexes by vagal afferents in sodium-depleted dogs.

Reduction of sodium intake affects both the renin-angiotensin and sympathetic nervous systems, but the effects on the latter are less well understood. To clarify this relationship, the responsiveness of the baroreceptor reflex was compared in groups of normal and sodium-depleted dogs prepared with a single innervated carotid sinus and left vagus nerve after anesthesia with morphine-chloralose. Three weeks of sodium depletion did not affect the mean arterial blood pressure, but cardiac output (-50%) and stroke volume (-38%) were reduced, whereas there was a large compensatory increase in total peripheral resistance (115%). The pressor response to carotid occlusion in sodium-depleted dogs was significantly less (35 +/- 4 mmHg) than that obtained in normal dogs (61 +/- 5 mmHg). In the dogs treated with cholinergic blockade with atropine, this difference (-51%) persisted. In contrast, the pressor response to carotid occlusion in sodium-depleted dogs was significantly potentiated (112%) and restored in magnitude to that found in normal dogs after severing the only remaining vagus nerve. These data suggest that the cardiopulmonary and/or aortic vagal afferents are responsible for the blunting of baroreceptor reflexes during sodium depletion.

Afferent Pathways↗
PubMed1979

Ultrastructural types of cell in adrenal cortical adenoma with primary aldosteronism.

By means of electron microscopy, three types of cell were identified in the adrenal cortical adenomas obtained by surgery from three patients with primary aldosteronism. They were zona glomerulosa-type cells, compact cells and clear cells. The former two types of cell were quite similar to those found in the zona glomerulosa and the zona reticularis respectively. The clear cell with large lipid vacuoles possessed mitochondria similar to those found in the outer zona fasciculata. The ultrastructure of the vacuoles was rather complex and their relationship to those in the zona fasciculata cell was not clear. Glycogen particles in the beta-form, which were present in the zona glomerulosa and reticularis cell but not in the zona fasciculata cell, were observed within the cytoplasm of this tumour cell. The clear cells of the tumours were therefore considered to possess features of both the zona glomerulosa and the zona fasciculata cell.

Adenoma↗
PubMed1978

Cutaneous tubeless ureterostomy as a procedure to study renal function in conscious dogs.

We describe the results obtained with a modified technique for single-side cutaneous ureterostomy in awake mongrel dogs. The success of this surgical procedure was evaluated by intravenous pyelography and urinary cultures that ruled out infection. In addition, we investigated the effects of this procedure on the excretory capacity of the kidney with a diverted ureter. Average values for effective renal plasma flow and glomerular filtration rate were comparable to those obtained in the literature and in the constralateral untouched kidney of the same dogs. The results indicate that cutaneous ureterostomy can be used successfully to monitor renal function in awake dogs over periods of weeks or months.

Animals↗