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R Furuya

Publications and source records attributed to R Furuya.

At least 37 records · Page 2Linked to original sources
PubMed1997

Differential effects of thiopental on neuronal nicotinic acetylcholine receptors and P2X purinergic receptors in PC12 cells.

BACKGROUND: PC12 cells, derived from rat pheochromocytoma, express neuronal nicotinic acetylcholine receptors (nAchRs) and P2X purinergic receptors, both of which resemble the receptors in postganglionic sympathetic neurons. The former is the established and the latter is the putative receptor to mediate fast synaptic transmission. The authors investigated effects of thiopental on these two ligand-gated ion channels. METHODS: Whole cell currents were recorded in PC12 cells without treatment of nerve growth factor, using conventional whole cell patch clamp technique. Nicotine or adenosine triphosphate (ATP) 30 microM was applied for 4-5 s in the absence or presence of thiopental 3-300 microM. RESULTS: Nicotine induced the rapidly decaying inward current at -60 mV, which exhibited the characteristics of the neuronal nAchR-mediated current. Thiopental inhibited the nicotine-induced inward current and accelerated the current decay in a dose-dependent manner, resulting in the greater effects on the steady current than the peak current. IC50s for the peak and steady current were 56.7 and 7.4 microM, when the anesthetic was coapplied with nicotine. Thiopental's inhibition was not associated with a change in the reversal potential and was voltage-independent at membrane potential of -30 to -70 mV. Most of thiopental's effects seemed to require channel opening. In contrast to the nicotine-induced current, thiopental had little effect on the current elicited by ATP. CONCLUSIONS: Thiopental, whose reported EC50 for general anesthesia is 25 microM, inhibited the neuronal nAchR-mediated current but not the P2X receptor-mediated response in PC12 cells at clinically relevant concentrations. Inhibition may result in suppression of synaptic transmission in sympathetic ganglia.

Adenosine Triphosphate↗
PubMed1994

Nephrogenic diabetes insipidus associated with bilateral ureteral obstruction.

Nephrogenic diabetes insipidus associated with ureteral obstruction is rare. We report a case of nephrogenic diabetes insipidus associated with ureteral obstruction caused by ileal leiomyosarcoma in a 32-year-old man. The treatment with trichlorothiazide and diclofenac sodium reduced urine output from 8 L/day to 4 L/day. Six months after nephrostomy, urine output decreased to 2.5 L/day without any drug administration. This case suggests that ureteral obstruction may cause an increase in urine output to 8 L/day and that surgical treatment for ureteral obstruction is effective in reducing urine output in nephrogenic diabetes insipidus patients with ureteral obstruction.

Adult↗
PubMed1994

Erythropoietin production in patients with chronic renal failure.

Studies were performed to reexamine the response of erythropoietin (Epo) production to acute hypoxic stimuli in patients with end-stage renal disease (ESRD). In the absence of acute bleeding or hypoxia, the serum Epo level in ESRD was similar to that of normal subjects despite severe anemia. In 11 dialysis patients with acute bleeding, the decrease in the Hb level from 8.9 to 5.8 g/dL provoked a significant increase in serum Epo up to 52.2 times the normal value. The increase in serum Epo was associated with a significant increase in corrected reticulocyte. Systemic hypoxemia (PaO2 < 65 mm Hg) in 8 dialysis patients provoked a significant elevation in the serum Epo level up to 24.6 times the normal level. There was an inverse relationship between serum Epo and arterial PaO2 (r = -0.715). The serum Epo level in these patients declined to or near the normal value after recovery from acute hypoxic stress. These data suggest that the ability of the Epo production is well preserved in ESRD, indicating that acute hypoxic stimuli provoke a significant increase in serum Epo.

Acute Disease↗
PubMed1993

Thalamic- and cerebellar-projecting interpolaris neuron responses to afferent inputs.

Thalamic- and cerebellar-projecting interpolaris neuron responses to afferent inputs from the temporomandibular joint (TMJ) and/or the masseter muscle (Mm) were examined in rats. Of 230 neurons tested, 24 could be antidromically stimulated from the contralateral ventral posteromedial thalamic nucleus (VPM), and 27 of 91 neurons tested were stimulated from the ipsilateral posteromedial part of crus II of the cerebellar cortex. None had dual projections. The thalamic-projecting neurons were recorded in the dorsomedial region of the interpolaris; most cerebellar-projecting neurons were at the medial border of the interpolaris. Ten of 24 thalamic- and 17 of 27 cerebellar-projecting neurons received nociceptive information. Afferent inputs from the TMJ and the Mm converged on 6 of 24 thalamic-projecting neurons and on 16 of 27 cerebellar-projecting neurons. In both the thalamic- and cerebellar-projecting neurons, there was no difference between the non-nociceptive and nociceptive neurons in mean antidromic latency. The results suggest that the interpolaris integrates and relays afferent inputs from deep oral structures.

Afferent Pathways↗
PubMed1993

Reversible acute renal failure in idiopathic nephrotic syndrome.

Acute renal insufficiency developed in four idiopathic nephrotic patients with minimal change or mild proliferative glomerulonephritis. The reduction in glomerular filtration rate (CInulin) was not in proportion to the renal plasma flow (CPAH) as evidenced by a low filtration fraction. Diuretic therapy failed to reverse renal insufficiency, and renal biopsy showed no evidence of interstitial nephritis, acute tubular necrosis or interstitial edema. Corticosteroid therapy induced a recovery of renal function with a decrease in proteinuria. These observations suggest that acute renal insufficiency in the idiopathic nephrotic syndrome might be caused by impaired glomerular permeability.

Acute Kidney Injury↗
PubMed1993

Spontaneous bacterial peritonitis in an adult patient with nephrotic syndrome.

Most cases of spontaneous bacterial peritonitis (SBP) in association with nephrotic syndrome are children. The complication of SBP in adults with nephrotic syndrome is extremely rare. Herein, we report a 25-year-old man with nephrotic syndrome and chronic renal failure who suffered from SBP. Citrobacter freundii was isolated from ascites. Irreversible deterioration of renal function followed the development of SBP, though the peritonitis was cured with antibiotic treatment. This case suggests that SBP is a rare, but serious complication of adult nephrotic syndrome with ascites.

Adult↗
PubMed1991

[The ventilatory response to CO2 during end-expiratory negative extra-thoracic pressure and PEEP].

The effects of end-expiratory negative extra-thoracic pressure (EENETP) and PEEP on the ventilatory response to CO2 were studied in seven healthy volunteers. The changes in functional residual capacity during EENETP -20 cmH2O and PEEP 5 cmH2O were 13.9 and 12.9 ml.kg-1, respectively. The slopes of CO2 response (minute ventilation/end-tidal CO2) during ZEEP, EENETP and PEEP were 0.913, 0.622, 0.693 l.min-1.mmHg-1, respectively. The slopes during EENETP and PEEP were significantly decreased. These results indicate that EENETP and PEEP could worsen the CO2 response in patients with respiratory failure, especially, with chronic obstructive pulmonary disease in which functional residual capacity is increased.

Adult↗