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Biomedical subjects

S Sagawa

Publications and source records attributed to S Sagawa.

At least 55 records · Page 3Linked to original sources
PubMed1990

Cardiovascular, renal, and endocrine responses in male quadriplegics during head-out water immersion.

The present study was undertaken to determine the relative influence of the action of the central nervous system on the mechanism of water-immersion-induced diuresis by comparing physiological responses of quadriplegic (QP) and normal subjects. After overnight fasting seven male QP subjects with complete cervical cord transections (C5-C8) and six normal men were tested before, during, and after 3 h of head-out immersion (HOI) in thermoneutral water (34.5-35.0 degrees C). The reversible increase in urine flow and the total urine volume (309 +/- 53 ml in 3 h) in QP subjects were comparable with that of the normal subjects (318 +/- 96 ml in 3 h). While osmolal excretion was increased in QP subjects, its magnitude was less when compared with that of normal subjects. Instead, the increased urine flow in QP subjects was characterized by increased glomerular filtration rate (GFR) and free water clearance, in contrast to a predominantly osmotic diuresis with no changes in GFR in the normal subjects. The HOI elevated (P less than 0.05) systolic pressure only in QP subjects, whereas the increase in cardiac output was the same in both groups. While plasma renin activity and aldosterone responses to HOI in QP subjects were comparable with those of normal individuals, plasma atrial natriuretic factor (ANF) in QP subjects was twofold higher (P less than 0.05) during HOI, and the approximately threefold increase in ANF (P less than 0.05) in QP subjects due to HOI was the same as that of normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Changes in insulation of body tissue and wet suits during underwater exercise at various atmospheric pressures.

To clarify the independent changes of insulations of body tissues (Itissue) and wet suit (Isuit) in the wet-suited subject during underwater exercise, overall heat flow from the skin (Htissue) and wet suit (Hsuit) and esophageal (Tes), skin (Tsk), and wet suit temperatures were measured at 1, 2, and 2.5 atmospheres absolute (ATA) at critical water temperature (Tcw). The average Tcw in nine wet-suited men (23-38 yr) was 22.3 +/- 0.2, 26.3 +/- 0.2, and 28.0 +/- 0.4 degrees C (SE) at 1, 2, and 2.5 ATA, respectively. At Tcw of each pressure male volunteers wearing 5-mm neoprene wet suits completed three 2-h experiments while immersed up to the neck. During one experiment the subjects remained at rest, and in the other two they exercised on an underwater ergometer at two different intensities (2 and 3 met). Tes significantly declined (P less than 0.05) over 2 h from 37.1 to 36.5 degrees C during rest in each pressure. The 2-met exercise prevented Tes from falling in all pressures, and the 3-met exercise elevated Tes by 0.2-0.3 degrees C. There was no exercise-dependent difference in Isuit, but a pressure-dependent difference was remarkable. The Itissue at rest was identical for all pressures; however, it progressively decreased as a function of exercise intensity. It is concluded that overall Itissue is entirely determined by work intensity at Tcw, but not by atmospheric pressure. On the contrary, Isuit at Tcw is solely dependent on the pressure, but not on the work intensity.

Adult↗
PubMed1990

Characteristics of increased urine flow during a dry saturation dive at 31 ATA.

Three male divers were subjected to a 7-day dry saturation dive at 31 ATA (New Seatopia). Urine samples were collected for measurements of electrolytes and creatinine for glomerular filtration rate (GFR) 5 times daily, at 3-h intervals during daytime (0700-2200 h) and once at night (2200-0700 h). Collections were taken for 2 days before (predive 1 ATA air), 7 days during 31 ATA exposure, and during 10 days of decompression and for 2 days at postdive 1 ATA air. Blood samples were taken after overnight fasting at each of the dive periods for measurements of atrial natriuretic factor (ANF), electrolytes, and other blood constituents. Compression to 31 ATA resulted in a twofold increase in urine flow accompanied by increases in excretion of osmotic substances (+40%) and sodium (+54%), and a reduction in urine osmolality (-32%). The increase in urine volume was greater (P less than 0.05) at night than day with no change in GFR between day and night, confirming the earlier findings. However, no change in plasma ANF was observed in spite of a sustained increase in daily sodium and water excretion at high pressure. These results suggest that the hyperbaric diuresis-natriuresis may not be directly mediated by the ANF release.

Adult↗
PubMed1989

Remarkable effect of endocrine therapy on brain metastasis from prostatic carcinoma.

The brain metastasis of prostatic carcinoma is rare and is distinguished by its poor prognosis in cases which are not surgically resectable. Herein we report on a case of brain metastasis of prostatic carcinoma which showed a dramatic regression through bilateral orchiectomy and doses of diethylstilbestrol diphosphate and estramustine phosphate. Neurologic and psychiatric symptoms diminished within three months, and the patient is alive and well without any subjective symptoms after twelve months.

Adenocarcinoma↗
PubMed1989

Renal sympathetic nerve activity and natriuresis during water immersion in conscious dogs.

The role of renal sympathetic nerve activity (RSNA) in the natriuresis and diuresis induced by head-out water immersion (WI) was studied in eight conscious female dogs. The dog was instrumented chronically with a stainless steel electrode for the measurement of RSNA and two catheters for the measurements of systemic arterial (Pa) and central venous (Pv) pressures. The WI caused an immediate reduction of RSNA by 43 +/- 7% (P less than 0.05), and this low level was sustained throughout a 120-min WI under thermoneutral conditions (37 degrees C). Urine flow and sodium excretion increased by 211 +/- 54 (P less than 0.05) and 240 +/- 122% (P less than 0.05), respectively, but creatinine clearance did not change significantly during WI. A step increase in Pa (by 10 +/- 4 mmHg, P less than 0.05) and Pv (by 10.0 +/- 0.8 mmHg, P less than 0.05) was observed also during WI. In another series of studies, renal denervations were performed 2-4 wk before the experiment in six of the same dogs. Dogs with renal denervation showed no significant changes in urine flow and sodium excretion in response to WI, whereas Pa and Pv increased by 10 +/- 7 and 10.0 +/- 2.0 mmHg relative to the control level, respectively. It is concluded that the reduction of RSNA observed during WI plays a major role in the natriuresis in the dog.

Animals↗
PubMed1989

[Clinical evaluation of cefixime (CFIX) in the treatment of urinary tract infection].

Cefixime (CFIX, Cefspan), a new oral cephem, was used in the treatment of urinary tract infections, and was evaluated for its therapeutic effectiveness and safety at the Department of Urology, Osaka University Hospital and 16 affiliated hospitals. A total of 238 patients were administered daily doses of 200 or 400 mg. Clinical efficacy was assessed on 92 female patients with acute uncomplicated cystitis and 42 patients with complicated UTI according to the Criteria for Clinical Evaluation of Antimicrobial Agents in UTI (3rd ed.) recommended by the Japan UTI Committee, to which we added our own minimum modification. Clinical efficacy was evaluated as excellent in 57 of the acute uncomplicated cystitis cases, moderate in 33 and poor in 2, with an overall clinical effectiveness rate of 98%. Clinical efficacy was evaluated as excellent in 12 of the complicated UTI cases moderate in 12 and poor in 18, with an overall clinical effectiveness rate of 57%. In one case of uncomplicated pyelonephritis, CFIX showed an excellent efficacy. Of the total of 102 bacterial strains isolated from uncomplicated UTIs, 95 (93%) were eradicated by CFIX, while 36 (72%) eradicated in 50 strains isolated from complicated UTIs. Subjective adverse reactions were seen in 4 cases (1.7%) of the 236 patients, as generalized pruritus and upper gastrointestinal discomforts. Abnormal laboratory findings were recorded in 6 out of 141 cases. They were increases in serum GPT, GOT, alkaline phosphatases, total bilirubin, as well as increases in peripheral leukocytes. These adverse symptoms and abnormal laboratory findings disappeared after the termination of CFIX administration. CFIX might therefore be considered as a clinically useful oral antibiotic in the treatment of UTI.

Administration, Oral↗
PubMed1988

Sweating and cardiovascular responses of aged men to heat exposure.

In this study, 6 older and 10 younger Japanese men were exposed, while sitting, to 40 degrees C and 40% relative humidity for up to 130 min. All participants were heat unacclimatized. Physiological measurements included sweat responses, esophageal and skin temperatures, nonevaporative heat exchange, heart rate, cardiac output, blood pressure, forearm blood flow, and metabolic heat production. There was no significant difference in sweat rate or in onset of sweating between the older and younger men; however, esophageal temperature at the onset of sweating was greater in the older men. Changes in skin temperature, nonevaporative heat exchange, metabolic heat production, heart rate, and cardiac output were the same during heat exposure in both age groups. However, forearm blood flow before and after exposure to heat was significantly lower in the elderly group. These data suggest that the greater health risk posed to resting, yet healthy, aged men by hot environments is not a consequence of inadequate sweating but could be associated with retardation of the vasodilation reflex, which can prevent effective transfer of the body heat to its shell, thus resulting in greater heat storage.

Adult↗
PubMed1988

Atrial natriuretic factor during head-out immersion at night.

The present investigation was undertaken to test the hypothesis that a circadian variation in the atrial natriuretic factor (ANF) response is responsible for the nocturnal inhibition of renal responses to head-out immersion (HOI). Plasma ANF responses to a 3-h HOI (water temperature 34.5 +/- 0.5 degrees C) were studied during day (1000-1300) and night (2400-0300) in six hydropenic male human subjects. In agreement with the previous observations, the renal responses, especially the diuresis, to HOI were attenuated at night compared with the day; furthermore, plasma renin activity decreased to the same low level during HOI at both day and night. Plasma ANF during time control periods was 30-40 pg/ml without showing any circadian variation. Moreover, plasma ANF showed a similar twofold increase within 1 h of HOI and was maintained at this elevated level throughout the 3-h HOI period in both the daytime and the nighttime series. On termination of HOI, plasma ANF decreased linearly to the pre-HOI level within 1 h. Hematocrit during time control periods was higher during the day compared with the night (P less than 0.05). Although HOI appears to induce a transient increase in plasma volume (as indicated by decreases in hematocrit) during the 1 h of HOI, the magnitude of the decrease in the latter parameters was not different between day and night. It is concluded that nocturnal inhibition of renal responses to HOI cannot be fully accounted for by circadian differences in the ANF and fluid shift response to HOI.

Adult↗
PubMed1988

Renal and endocrine responses in the elderly during head-out water immersion.

After overnight food and fluid restriction, seven healthy old (62-74 yr) and eight young (21-28 yr) men were examined before, during, and after 3-h head-out immersion (HOI) in thermoneutral water (34.5 +/- 0.5 degrees C). On separate days, all subjects remained seated in air for 5 h to obtain the time control data. Although HOI induced a reversible increase in urine flow in all subjects, the response was faster and greater in magnitude in the elderly than in the young. Na excretion and osmolal clearance also followed a response pattern identical to that of urine flow; thus the HOI-induced diuresis was entirely osmotic. Endogenous creatinine clearance increased in the elderly at 2 h of HOI, suggesting an age-related modification in kidney hemodynamics. Although there was virtually the same cephalad blood shift (measured by impedance cardiography), mean arterial pressure significantly increased (P less than 0.05) during HOI in the elderly, which also indicated a different response of peripheral circulation to HOI in the elderly. Control level of plasma atrial natriuretic factor (ANF) was nearly twofold greater in the elderly compared with the young. The HOI induced a nearly fourfold increase in ANF in the elderly, whereas that for the young was threefold. Both plasma aldosterone and ADH responses to HOI were attenuated in the elderly compared with the young, which had no correlation with urine flow or Na excretion. It is concluded that the elderly release more ANF at a given cephalad volume expansion compared with the young, but the vasodilative reaction to ANF was attenuated in the elderly.

Adult↗
PubMed1988

Critical water temperature during water immersion at various atmospheric pressures.

The present work was undertaken to determine the effect of atmospheric pressure [ranging from a high altitude of 4,300 m above sea level or 0.6 atmospheres absolute (ATA) to depths of 10 m deep or 2 ATA] on the critical water temperature (Tcw), defined as the lowest water temperature a subject can tolerate at rest for 2 h without shivering, of the unprotected subject during water immersion. Nine healthy males wearing only shorts were subjected to immersion to the neck in water at 0.6, 1, and 2 ATA while resting for 2 h. Continuous measurements included esophageal (Tes) and skin (Tsk) temperatures, direct heat loss from the skin (Htissue), and insulation of the tissue (Itissue). The Tcw was significantly higher at 0.6 ATA than 1 and 2 ATA: however, Tcw at 1 ATA was identical to that at 2 ATA. The metabolic heat production remained unchanged among the pressures. During the 2-h immersion in Tcw, Tes was identical among all atmospheric pressures: however, Tsk was significantly higher (P less than 0.05) at 0.6 ATA and was identical between 1 and 2 ATA. The overall mean Itissue was near maximal during immersion in Tcw in each pressure, and no difference was detected among the pressures. However, Itissue at the acral extremities (arm, hand, and foot) decreased significantly at 0.6 ATA, and subsequently heat loss from these parts was increased, which elevated an extremity-to-trunk heat loss ratio to 1.4 at 0.6 ATA from 1.1 at 1 and 2 ATA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Independence of brain and tympanic temperatures in an unanesthetized human.

Temperature within the brain and the esophagus and at the tympanum were obtained in a 12-yr-old male in a series of experiments that began 8 days after surgery for implantation of a drainage catheter. Fanning the face did reduce tympanic temperature but not temperature in the brain; brain temperatures followed esophageal temperatures. In long-term monitoring, temperature in the lateral ventricle was 0.5 degree C above esophageal temperature and 0.2 degree C below that in white matter 1 cm above, with the offsets fixed throughout the overnight cycle. All temperatures went through similar excursions when the face was excluded from fanning applied to the body. These observations highlight the fact that in humans the defense against hyperthermia takes advantage of cooling distributed over the entire skin surface.

Body Temperature Regulation↗
PubMed1988

Water temperature and intensity of exercise in maintenance of thermal equilibrium.

This study examined the thermal and metabolic responses of six men during exercise in water at critical temperature (Tcw, 31.2 +/- 0.5 degrees C), below Tcw (BTcw, 28.8 +/- 0.6 degrees C), at thermoneutrality (Ttn, 34 degrees C), and above Ttn (ATtn, 36 degrees C). At each water temperature (Tw) male volunteers wearing only swimming trunks completed four 1-h experiments while immersed up to the neck. During one experiment, subjects remained at rest (R), and the other three performed leg exercise (LE) at three different intensities (LE-1, 2 MET; LE-2, 3 MET; LE-3, 4 MET). In water warmer than Tcw, there was no difference in metabolic rate (M) during R. The M for each work load was independent of Tw. Esophageal temperature (Tes) remained unchanged during R in water of ATtn (36 degrees C). However, Tes significantly (P less than 0.05) declined over 1 h during R at Ttn (delta Tes = -0.39 degrees C), Tcw (delta Tes = -0.54 degrees C), and BTcw (delta Tes = -0.61 degrees C). All levels of underwater exercise elevated Tes and M compared with R at all Tw. In water colder than Tcw, the ratio of heat loss from limbs compared with the trunk became greater as LE intensity increased, indicating a preferential increase in heat loss from the limbs in cool water. Tissue insulation (Itissue) was lower during LE than at R and was inversely proportional to the increase in LE intensity. A linearly inverse relationship was established between Tw and M in maintaining thermal equilibrium.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Small cell carcinoma of the urinary bladder: a case of remarkable remission with combined chemotherapy.

A 67-year-old man presented with asymptomatic gross hematuria. Cystoscopy and radiographic studies revealed a large tumor on the left lateral wall of the urinary bladder. Also, computer tomographic (CT) scan of the pelvic cavity showed metastasis to the left external iliac node. The light microscopic appearance of cold punch biopsy specimens for the tumor was closely akin to small cell carcinoma of the lung. Ultrastructurally, the tumor cells exhibited small numbers of neurosecretory granules in the cytoplasm. After surgical treatment, the patient was treated with combined chemotherapy using cis-diamminedichloroplatinum (CDDP) and etoposide. On CT scan, a remarkable remission was shown to have been induced at the metastatic site after three cycles of the therapy. Though the morphology of bladder tumors has not received very much attention, this report emphasizes that detailed pathological examination is of therapeutic importance.

Aged↗
PubMed1987

Descending and segmental spinal pathways differently regulate contractions of antagonistic muscles of frogs in vitro.

A comparison of fibres descending through the ventral column and segmental afferent fibres was carried out using an isolated frog spinal cord-nerve-muscle preparation with a pair of antagonistic muscles. The m. tibialis anterior (TIB) was contracted with stimulation of the ventral column much stronger than with that of the dorsal root (DR). Contraction of the m. gastrocnemius (GAS) was selectively induced with DR stimulation. These results suggest that the descending fibres and segmental afferent fibres preferentially regulate contractions of the flexor (the TIB) and the extensor (the GAS), respectively. Effects of alpha-aminoadipate, methysergide and LSD were also examined.

2-Aminoadipic Acid↗
PubMed1987

Physiological responses of aged men to head-up tilt during heat exposure.

The effects of age on cardiovascular and thermoregulatory responses to passive tilting were investigated using six old (61-73 yr) and 10 young (21-39 yr) unacclimatized men. Experiments were carried out at 26 degrees C and after exposure to 40 degrees C and 40% relative humidity for 105 min. Continuous measurements of esophageal (Tes) and mean skin (Tsk) temperatures and heart rate (HR) were recorded. Other variables studied included blood pressure (BP), forearm blood flow (FBF), and cardiac output (CO), which were measured at 4- to 5-min intervals. Measurements were made in the supine position and after 70 degrees head-up tilt for 15 min. Cardioacceleration during the tilt test was greater in the young men than in the old. Other cardiovascular responses of the old men to orthostatism were qualitatively similar to that of the young except for FBF and forearm vascular conductance. The old men did not show significant changes in FBF during tilting, suggesting a deterioration in the sympathetic nervous reflex in the aged. However, other circulatory adaptations seemed to overcome this deficiency resulting in orthostatic tolerance similar to that of the young. During head-up tilt at 26 and 40 degrees C, Tes of both age groups increased. This may reflect a decrease in conductive heat transfer presumably due to diminished blood flow to the periphery.

Aged↗
PubMed1987

[A clinical study on 34 cases of urothelial cancer of upper urinary tract].

Thirty-four cases of tumor of the renal pelvis or ureter or both have been treated in our department during the past decade. The primary tumor was in the renal pelvis in 11 cases, in the ureter in 21 cases and in the ureter and renal pelvis in 2 cases, a co-existent tumor in the bladder was found in 4 cases. Seventeen patients had a tumor on the right side and 17 on the left side. The most frequent symptom was gross hematuria (70.6%) and flank pain was the presenting symptom in 7 cases (20.6%). On the intravenous pyelography, a filling defect in the renal pelvis or ureter (41.2%) and nonvisualization (53.0%) were frequent findings. Twenty-nine cases had undergone total nephroureterectomy with resection of a bladder cuff, 3 had simple nephrectomy and 2 had open biopsy alone. Postoperative radiation therapy was done in 1 case, chemotherapy in 10 cases, and 6 cases of them were treated by CAP therapy (cis-dichlorodiamine platinum, doxorubicin and cyclophosphamide). Actual and relative 5-year survival rates were 53.8% and 63.5%, and no significant difference was found in survival rate between the patients with renal pelvic tumors and those with ureteral tumors.

Aged↗
PubMed1987

Seadragon VI: a 7-day dry saturation dive at 31 ATA. II. Characteristics of diuresis and nocturia.

Four male divers were exposed to a dry, 31 ATA, He-O2 environment for 7 d (Seadragon VI). Urine was collected diurnally (0700-2200 h) and nocturnally (2200-0700 h) before (predive 1 ATA air), during, and after (decompression and postdive 1 ATA air) exposure to 31 ATA. A typical hyperbaric diuresis associated with a reduction in urine osmolality was observed in the face of a constant creatinine clearance. A significant increase (P less than 0.05) in osmolal clearance (COSM) was observed with concomitant decrease (P less than 0.05) in negative free water clearance, indicating that the diuresis has both osmotic and free water components. Although urine flow increased at pressure during both day and night, its magnitude was twofold greater at night as compared to daytime. Moreover, the diurnal diuresis was entirely due to an increase in free water excretion, whereas the nocturnal diuresis was largely due to an increased COSM. These results indicate that hyperbaric diuresis is induced by inhibition of tubular reabsorption of free water during daytime and of certain solutes during the night. Approximately 80% of the nocturnal increase in the excretion of osmotic substances was accounted for by Na, K, Cl, and urea.

Adult↗