Clinical Evaluation of a New Type of Centrifugal Pump

Abstract: The major problems with existing centrifugal pumps are leakage, mechanical trauma, and thrombus formation. In consideration of these problems, a new compact centrifugal pump system was developed. The purpose of this study was to evaluate the new centrifugal pump system clinically. Ten patients underwent open heart surgery with a centrifugal pump or a roller pump. During surgery, hemodynamic and hematological data were obtained. A pulsatile assist device in the pump circuit was used in patients with severe heart disease. There was neither operative death nor hospital mortality, and there was no difference with regard to hemodynamic data between the two groups. The centrifugal pump group, however, had significantly lower hemolysis, especially during prolonged cardiopulmonary bypass. This centrifugal pump could also create sufficient pulsatile flow with a pulsatile assist device. Postoperative macroscopic and microscopic findings demonstrated the smooth surface of the pump without thrombus formation. This centrifugal pump system might be useful for prolonged cardiopulmonary bypass.     

gamma-Aminobutyric acid enhances the tone of human internal anal sphincter.

The effect of gamma-aminobutyric acid (GABA) on the human internal anal sphincter was investigated. Cumulative applications of GABA produced concentration-dependent contractions (10(-8)-10(-5) M) of the isolated human sphincter. Pretreatment with bicuculline (GABAA antagonist) turned them to relaxation. Muscimol, a GABAA agonist, induced concentration-dependent contractions (10(-8)-10(-5) M); however, baclofen (GABAB agonist, 10(-8)-10(-5) M) promoted concentration-dependent relaxation of the strips. These results suggested that both excitatory GABAA receptors and inhibitory GABAB receptors exist in the internal anal sphincter. Oral administration of sodium valproate (1600 mg/day), a GABA transaminase inhibitor, enhanced the anal canal resting pressure in 10 normal volunteers. Anal manometry showed a significant elevation in tonus without affecting amplitudes or frequencies. These results indicated that endogenous GABA, which was increased by sodium valproate, produced elevations in the anal canal resting pressure through its specific receptors in the human internal anal sphincter.     

Spermidine/Spermine N-Acetyltransferase, a New Biochemical Marker for Epithelial Proliferation in Rat Bladder

We examined the activity of spermidine/spermine N ¹-acetyltransferase (SAT), a rate-limiting enzyme of the biodegradation of polyamines, in N -butyl- N -(4–hydroxybutyI)nitrosamine-induced transitional cell carcinoma (TCC) and melamine-induced papillomatosis of rat bladder, and compared the activity to that of ornithine decarboxylase (ODC). Both activities were higher in both lesions than in control rats. The difference between SAT and ODC activities in cancerous tissue and papillomatosis was not significant. Cells stained for proliferating cell nuclear antigen (PCNA) were abundant in papillomatosis. TCC had areas with much PCNA. The results indicated that an elevation of SAT activity occurs in both reversible and irreversible proliferation of bladder epithelium and could be important in bladder carcinogenesis.     

A case of hair loss induced by carbamazepine]

We report a 52 year-old man presenting with an acute considerable hair loss induced by carbamazepine (CBZ). The remarkable scalp hair loss started within a week after CBZ administration. There was no evidence of dermatitis or allergic reaction, or other cause for the hair loss. The serum concentration of CBZ was 8.6 microg/ml (therapeutic range 8-12 microg/ml). CBZ was discontinued, and the hair loss stopped within several days with new hair growth. Medication-induced hair loss is an occasional adverse effect of many drugs used for neuropsychological diseases. CBZ also induces hair loss and its frequency was reported below 2%. Only a limited number of detailed case reports describing CBZ-induced hair loss were available, and we found these cases could divide into two groups with regard to a delay in starting hair loss after administration of CBZ. In one group, the hair loss started within a week suggesting anagen effluvium and in another it started after two or three months suggesting telogen effluvium. This finding suggests the causative mechanism of CBZ-induced hair loss is not unitary.     

Renovascular hypertension: a unique cause of unilateral focal segmental glomerulosclerosis.

A 48-year-old man presented with malignant hypertension and massive proteinuria. Renal angiography showed complete obstruction of the left renal artery and 99mTc-mercaptoacetylglycine (MAG3) renography showed a nonfunctioning left kidney. Percutaneous transluminal renal angioplasty of the left renal artery was unsuccessful; hence, the patient underwent left nephrectomy because of uncontrolled hypertension and proteinuria. Histological examination of a right kidney specimen revealed lesions of focal segmental glomerulosclerosis with benign nephrosclerosis. In contrast, histology of the left kidney showed typical ischemic kidney with hypertrophy of arteriolar smooth muscle cells. The patient responded favorably to the nephrectomy, as his blood pressure and urinary protein dramatically decreased with no antihypertensive medication. This case illustrates the heterogeneous effect of the renin-angiotensin system on either kidney in patients with renovascular hypertension due to unilateral renal artery stenosis.     

Changes in left ventricular function during exercise after lung resection--study with a nuclear stethoscope]

In 29 cases undergoing lung resection, effects of the surgery on left ventricular function were investigated indirectly with a Nuclear Stethoscope. Various parameters were measured following an exercise load before and after surgery. There were significant decreases in post-operative resting levels of stroke volume (SV) (p < 0.001), end-diastolic volume (EDV) (p < 0.001), ejection fraction (EF) (p < 0.05) and ejection rate (ER) (p < 0.001) and significant increase in heart rate (HR) (p < 0.001) when compared to pre-operative resting levels. Neither filling rate (FR) nor cardiac output (CO) showed significant difference. At maximum exercise load, there were significant decreases in post-operative EDV (p < 0.005), SV (p < 0.005), ER (p < 0.001) and FR (p < 0.005), but no significant differences were detected in HR and EF; consequently, there was a significant decrease in CO (p < 0.005). Ratio of the levels at maximum load to those at resting of each parameter did not show significant difference between before and after operation with regard to any parameters except CO and FR which showed significant decrease (p < 0.005 and p < 0.001, respectively). Effects of the surgery on left ventricular function were studied according to amount of lung resection. In 13 cases where more than two lobes were resected, similar significant differences to those mentioned above were found in all parameters except EF. In cases where a single lobe was resected, only ER and FR showed similar tendency to that described above. Effects of the surgery on left ventricular function were also studied according to age of patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Blood pressure changes following extracorporeal shock wave lithotripsy for urolithiasis.

Hypertension after extracorporeal shock wave lithotripsy (ESWL) has been a controversial subject. Changes in blood pressure were studied in 262 patients (mean age 47.8 years) 18.6 months after ESWL. According to World Health Organization criteria the number of patients who showed a decrease exceeded those who showed an increase in blood pressure. The patients who have been on antihypertensive therapy showed a significantly greater decrease in blood pressure than those without medication. Of 192 normotensive patients diastolic pressure increased 1.2 mm. Hg and 2 (1.0%) had hypertension 18.4 months after ESWL. Annualized increase in diastolic pressure and new onset of hypertension were calculated to be 0.78 mm. Hg and 0.65%, respectively. Significant elevation of diastolic pressure was noted in the patients who received a larger number of shock waves. Blood pressure should be carefully followed after ESWL especially in patients who have been treated by a greater number of shock waves.     

Intravitreal injection of 0.3 ml of SF6 gas for persistent subfoveal fluid after scleral buckling for rhegmatogenous retinal detachment

Purpose  To determine the efficacy of intravitreal injection of sulphur hexafluoride (SF6) gas for reducing persistent subfoveal fluid after scleral buckling surgery for macula-off rhegmatogenous retinal detachments. Methods  We injected 0.3 ml of SF6 gas into the vitreous cavity of two eyes of two patients with persistent macular retinal detachment 3 and 5 months after successful scleral buckling. Optical coherence tomography was performed before and after surgery. Results  Subfoveal fluid was displaced peripheral to the fovea immediately after gas injection and the fluid was absorbed gradually in both eyes. Conclusions  Persistent subfoveal fluid after scleral buckling may be treated with intravitreal SF6 gas injection. The authors have no proprietary interest in any aspect of this report