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Biomedical subjects

H Kobayakawa

Publications and source records attributed to H Kobayakawa.

At least 37 records · Page 2Linked to original sources
PubMed1990

Beta-2-microglobulin generation rate and clearance rate in maintenance hemodialysis patients.

We analyzed the rebound pattern of plasma beta 2-microglobulin (beta 2-m) concentration from 4 h after completion of hemodiafiltration until the start of the next treatment according to the one-pool beta 2-m kinetic model so as to determine beta 2-m generation rate and whole-body beta 2-m clearance. Next, we obtained the whole renal beta 2-m clearance as the product of renal creatinine clearance and the glomerular sieving coefficient of beta 2-m. Then, extrarenal beta 2-m clearance was calculated as the difference between whole-body beta 2-m clearance and whole renal beta 2-m clearance and renal beta 2-m clearance due to tubular absorption was taken to be the difference between whole renal beta 2-m clearance and renal beta 2-m clearance due to urinary excretion. The results showed that the higher the patients' plasma beta 2-m concentration was, the lower was the whole-body beta 2-m clearance. Moreover, in the present study, an inverse correlation was found between the following respective factors: plasma beta 2-m concentration and whole renal beta 2-m clearance; plasma concentration and renal clearance due to tubular absorption; plasma concentration and renal clearance due to urinary excretion. However, there was no correlation between plasma beta 2-m concentration and extrarenal beta 2-m clearance. The findings indicate that the variation of plasma beta 2-m concentration with the individual patient is solely attributable to the variation in residual renal function in terms of beta 2-m elimination.

Adult↗
PubMed1989

Comparison of various treatment modes in terms of beta 2-microglobulin removal: hemodialysis, hemofiltration, and push/pull HDF.

The beta 2-microglobulin clearance increased as the convective transport was added during hemodialysis to perform hemodiafiltration (HDF), suggesting that a convective transport type artificial kidney is more effective for beta 2-microglobulin removal. Actually, the decrease in the plasma beta 2-microglobulin level per treatment was more pronounced in hemofiltration and push/pull HDF than in hemodialysis. In the present study, no significant fluctuation in the pretreatment level of beta 2-microglobulin was shown by serial treatment by hemodialysis, whereas an obvious decreasing trend of it was indicated in serial treatment of either push/pull HDF or hemofiltration. Moreover, our study indicated that the ratio of posttreatment beta 2-microglobulin level in relation to its pretreatment level increases as the treatment by hemofiltration or push/pull HDF is repeated.

Amyloid↗
PubMed1989

Effects of L-carnitine administration on short-chain fatty acid (acetic acid) and long-chain fatty acid metabolism during hemodialysis.

The purpose of the study is to investigate the effects of L-carnitine on the exogenous acetate metabolism during hemodialysis together with the triglyceride and free fatty acid metabolism. Sixteen chronic renal failure patients on acetate dialysis were orally administered 1,200 mg of L-carnitine chloride per day for 12 weeks. Plasma triglyceride concentrations at 30 and 60 min following initiation of hemodialysis were significantly lower than before hemodialysis, while the plasma concentrations of free fatty acid at the same points into hemodialysis were significantly higher than before hemodialysis, whether L-carnitine chloride was being given or not. This is attributed to the enhanced degradation of triglyceride and the increased generation of the free fatty acid with heparin administration during hemodialysis. The L-carnitine chloride treatment did not affect the plasma triglyceride concentrations at 30 and 60 min into hemodialysis, whereas the free fatty acid concentrations at the same points into hemodialysis were significantly lower after L-carnitine chloride administration commenced than before it. This is attributed to the fact that fatty acid oxidation was enhanced following the L-carnitine chloride treatment. Compared to before the drug administration, the whole body clearance of exogenous acetate was significantly increased after the drug was given, and the plasma acetate level during hemodialysis fell accordingly. This is attributed to the fact that with L-carnitine chloride administration, the amount of accumulated acyl-CoA in the cytosol decreased and consequently the citrate cycle function increased.

Acetates↗
PubMed1989

Attenuated renal production of dopamine in patients with low renin essential hypertension.

Our previous studies have shown that a suppressed pressure natriuresis may contribute to the hypertensive mechanism in patients with essential hypertension (EHT), particularly in low renin patients (LRH). In this study, in order to clarify the role of renal dopaminergic activity in the blunted natriuresis of LRH, the conversion of 1-dopa (DOPA) to dopamine (DA) in the kidneys was investigated in 9 normotensive subjects (NT) and 20 EHT, including 15 normal renin EHT (NRH) and 5 LRH. All subjects were hospitalized and received a constant diet (Na:120mEq, K:75mEq daily). Plasma DOPA concentration (p-DOPA:HPLC-ECD), creatinine clearance (Ccr), urinary excretion of sodium (UNaV) and DA (UDA), as well as fractional excretion of sodium (FENa) were measured before and after the single oral administration of 1-DOPA (400mg). DOPA administration caused a significant increase of p-DOPA, UDA and FENa with undetectable DOPA levels in the urine in EHT. In addition, under the basal condition, UDA correlated positively with p-DOPA or the product of p-DOPA x Ccr, which might reflect the DOPA delivery at the renal proximal tubule. No significant difference was found in p-DOPA and the product of p-DOPA x Ccr among NT, NRH and LRH. However, the ratio of UDA/(p-DOPA x Ccr), which may indicate the conversion from DOPA to DA in the kidneys, was lower in EHT, especially in LRH, than that in NT. These results suggest that a reduced renal conversion from DOPA to DA may contribute to the attenuated natriuresis as well as renal dopaminergic activity in LRH.

Adolescent↗
PubMed1989

Interrelationship between plasma ionized calcium, plasma noradrenaline (NA) and pressor response to infused NA in patients with essential hypertension.

We evaluated the role of calcium metabolism on plasma noradrenaline concentration (pNA) and pressor response to infused noradrenaline (NA-R) in patients with mild-to-moderate essential hypertension (EHT). Mean arterial pressure (MAP), plasma ionized calcium (pCa2+), and NA-R were measured at the basal condition in 17 EHT and after the administration of calcium antagonist, nifedipine (60mg, t.i.d., for 4 weeks) in 9 EHT. Under basal condition, pCa2+ correlated positively with pNA and negatively with NA-R in EHT. Following nifedipine therapy, persistent reductions of MAP and NA-R, a transient increase in pNA and a sustained increase of urinary excretion of calcium were observed. On the other hand, no significant change in pCa2+ was found during the therapy. Percent change in MAP following 4 weeks of nifedipine administration correlated positively with pCa2+ and pNA before the therapy. In addition, change in NA-R by nifedipine therapy correlated positively with the basal values of pCa2+ and PNA and negatively with NA-R before the treatment. A significant negative correlation between NA-R and pNA was observed following nifedipine therapy as well as the basal state. However, the slope of the regression line between NA-R and pNA decreased significantly after the treatment as compared to the basal state. These results suggest that calcium metabolism relating sympathetic nerve activity and NA-R may contribute to the hypertensive mechanism in EHT. The hypotensive effects of nifedipine may be caused partly by the attenuation of sympathetic nerve activity and NA-R.

Blood Pressure↗
PubMed1989

[A case of bilateral testicular tumor].

A case of bilateral germ cell tumor of the testis is reported. In 1988, a 36-year-old male presented with painless swelling of left scrotal contents. Right orchiectomy and retroperitoneal lymph node dissection for embryonal carcinoma had been performed 5 years earlier. Left orchiectomy was performed and its histological finding was seminoma and embryonal carcinoma. Evaluations including CT scan and Ga scintigraphy revealed no metastasis. Postoperatively, the patient was treated with PVB therapy. Previous reports of bilateral germ cell testicular tumor were reviewed, and the age distribution, interval, and histological classification of these cases are discussed.

Adult↗
PubMed1989

[A case of bowenoid papulosis of the penis].

A 44-year-old man, who was seen for further examination of macroscopic hematuria, was found to have black eruptions on the penis and the scrotum. These eruptions appeared benign clinically, but on histological examination they showed the features of Bowen's disease. These eruptions were diagnosed as Bowenoid papulosis and were successfully treated with 5-FU cream. Twenty five cases of Bowenoid papulosis observed in men have been reported in Japan. Although Bowenoid papulosis is characterized by the histopathologic conditions of Bowen's disease, the lesions of Bowenoid papulosis differ clinically from those of Bowen's disease in several respects: onset at earlier average age, multiplicity of lesion, lack of associated symptoms, smaller size of the lesion, clinical morphologic features and possible spontaneous regression.

Adult↗
PubMed1989

Effects of nisoldipine on sympathetic activity, the renin-angiotensin-aldosterone system, and water-sodium-calcium metabolism in patients with essential hypertension.

The effects of nisoldipine (Bay k 5552), a long-acting Ca2+ antagonist, on sympathetic activity, the renin-angiotensin-aldosterone (RAA) system, the renal metabolism of water and electrolytes, and parathyroid hormone (PTH) were investigated following single dose and 4 weeks administration. The administration of nisoldipine led to the following results: 1. Mean arterial pressure (MAP) fell and heart rate slightly increased after the first dose, but did not show any appreciable change over 4 weeks treatment. 2. The urinary excretion of sodium, fractional excretion of sodium, plasma renin activity (PRA) and plasma noradrenaline concentration (pNA) were elevated initially, but the trend was to return to pretreatment levels after 4 weeks treatment. 3. A decrease in plasma aldosterone concentration was observed from the commencement of treatment. 4. Urinary excretion of calcium, fractional excretion of calcium and 24-h urine volume (UV) increased from the beginning, and maintained elevated levels after 4 weeks treatment. A decrease in body weight was also observed. 5. Plasma Ca2+ concentration did not change significantly throughout the treatment period, but PTH was decreased significantly both after 1 week and 4 weeks. 6. The percent changes in MAP (% delta MAP) after 4 weeks showed a significant negative correlation with pretreatment levels of MAP and the increment of UV (delta UV), as well as a positive correlation with pretreatment PRA or pNA levels. These findings suggest that in addition to its direct vasodilative effect, suppression of sympathetic activity and the renin-angiotensin-aldosterone system, reduction in body fluid and sodium, and a decrease in PTH and the related calciuresis may contribute to the hypotensive mechanism of nisoldipine.

Adult↗
PubMed1988

The pathophysiological role of water-sodium balance and renal dopaminergic activity in overweight patients with essential hypertension.

Studies were conducted to evaluate the role of water-sodium balance and renal dopaminergic activity in the hypertensive mechanisms of overweight patients with essential hypertension (EHT). The body mass index (BMI) was correlated positively with mean arterial pressure, plasma volume, extracellular fluid volume, or total exchangeable sodium and negatively with plasma noradrenaline concentration or plasma renin activity in patients with EHT. Fractional excretion of sodium (FENa) was significantly lower in overweight patients than in normal weight patients with EHT. Hypotensive effect of sodium restriction or the natriuretic response to infused dopamine was more remarkable in overweight patients with EHT than in normal weight patients with EHT. Urinary excretion of free dopamine (UDA) was correlated positively with simultaneously measured urinary excretion of sodium or FENa and negatively with the natriuretic response to dopamine infusion. In addition, UDA was positively correlated with the BMI in normal weight patients with EHT, whereas the relation between the UDA and the BMI was significantly negative in overweight patients with EHT. These findings suggest that the expansion of body fluid volume and sodium might result from the blunted natriuretic ability due to an attenuation of the renal dopaminergic activity in overweight patients with EHT. The expansion of body fluid volume and sodium may play an important role in the hypertensive mechanisms of overweight patients with EHT.

Adult↗
PubMed1988

The effect of ouabain on pressor responses to infused noradrenaline in patients with essential hypertension.

The relationship between changes in the pressor response to infused noradrenaline induced by intravenous injection of ouabain, an Na+,K+-ATPase inhibitor, and plasma renin activity and plasma ionized calcium was examined in 16 normotensive subjects and in 16 patients with essential hypertension. These patients were divided into 11 normal-renin and five low-renin essential hypertensives. The pressor response was significantly greater in low-renin hypertensives than in normotensives and normal-renin hypertensives. Following the injection of ouabain, the pressor response was significantly increased with no change in basal levels of blood pressure, plasma noradrenaline concentration, plasma calcium and plasma parathyroid hormone in both normotensives and essential hypertensives. The pressor response to noradrenaline was negatively correlated with levels of plasma noradrenaline and calcium after the injection of ouabain as well as before the injection in normotensives and essential hypertensives. The regression line between the pressor response and that of plasma noradrenaline or plasma calcium was significantly shifted towards a higher pressor response in normotensives, but not in essential hypertensives. The changes in the pressor response to noradrenaline induced by the injection of ouabain was significantly smaller in essential hypertensives, particularly in low-renin hypertensives, compared with normotensives. These results suggest that: (1) ouabain increases the pressor response to noradrenaline; (2) this increase is related to calcium metabolism; (3) endogenous Na+,K+-ATPase inhibitor(s) might be elevated in essential hypertensives; and (4) an increase in endogenous Na+,K+-ATPase inhibitor might, therefore contribute to an enhanced noradrenaline response in essential hypertensives, particularly in low-renin hypertensives.

Blood Pressure↗
PubMed1988

Role of hypovolemia in dialysis-induced hypotension.

Blood volume was measured continuously during hemodialysis using the authors' hematocrit continuous measurement system in an attempt to determine any relationship between dialysis-induced hypotension with acute onset and blood volume. Hypotension resulted approximately 3 h into dialysis in the present study. This point in time was that at which blood volume was more than 5% above the minimum level during the dialysis treatment, and in some patients it was more than 10% over the minimum level of blood volume. At the time dialysis-induced hypotension occurred or before, there was no sharp decrease in blood volume nor any change in the plasma refilling rate. This suggested that this hypotension is caused by a sudden breakdown of the blood pressure support mechanism compensating for decreased blood volume.

Blood Volume↗
PubMed1988

[Clinical studies of varicocele. 1: Clinical statistical analysis of varicocele].

A clinical statistical analysis was conducted of the patients with varicocele who visited the Department of Urology, Osaka City University, and its related hospitals. Regarding the age distribution, patients younger than 50 years old were predominant; this age group included 20 of 24 cases, or 83%. An overwhelming majority of the cases, 75%, had the main complaint of infertility; they had not been able to have children even after 2 to 3 years of marriage. The next most common complaint was swelling and/or an uncomfortable feeling of the contents of the scrotum. In all of the cases, the lesion was seen in the left side of the scrotum. When the patients were classified on the basis of the sperm count, oligospermia was predominant; it was seen in 15 cases (62.5%). A study on the relationship between the sperm count and the grade of varicocele revealed a tendency for the sperm count to show an inverse relationship with the grade. Testicular atrophy showed a direct correlation with the grade. Of the patients with varicocele, 5 patients had one or more children, while 8 patients (61.5%) complained of their inability to have a child. No particular relationship could be identified between the age at the time of visiting our Department as outpatients and the degree of testicular atrophy.

Adolescent↗
PubMed1988

[Clinical studies of varicocele. 2: Radiographic examination and measurement of spermatic vein pressure in varicocele patients].

There are two types of internal spermatic veins (ISV) by radiographic examinations. In type 1, ISV is dilated with some collateral venous branches. On the other hand, ISV of type 2 is narrowed with increased collateral venous branches or abnormalities such as the circumaortic renal are seen. In these groups, pressure of renal vein and ISV were measured. As a result, renal vein pressure was about the same in type 1 as in the controls at 9.5 +/- 2.3 cmH2O but was higher in type 2 at 17.0 +/- 2.8 cmH2O. As for ISV, it was also about the same in type 2 as in the controls at 13.9 +/- 6.8 cmH2O but was markedly higher in type 2 at 33.3 +/- 3.9 cmH2O. When selective renal venography was performed, a contrast medium back-flow was seen in 9 out of 11 type 1 varicocele patients, but it was not seen in any of the cases with the nutcracker phenomenon. These results suggested that type 1 may be caused by the structural and functional disorders in the valve between the renal vein and ISV. In contrast, pathogenesis of type 2 varicocele may be due to an abnormality of the ISV in the embryo.

Humans↗
PubMed1988

[Clinical studies of varicocele. 3: A rare venous return via Santorini's plexus in a varicocele patient. Report of a case].

A 12-year-old man was referred to our clinic because of sanguineous discharge. At the out-patient department, bilateral varicocele was found. Urinalysis showed microscopic hematuria, but no other laboratory data were abnormal. Excretion urography was normal. The retrograde phlebograph showed a rare venous return via Santorini's plexus and lumbar veins. After varicocelectomy, urinalysis improved.

Child↗
PubMed1988

[Transfer of cefoperazone into exudate from postoperative wound].

The levels of cefoperazone (CPZ) in the exudate from the postoperative would were measured in 10 cases for which CPZ was employed for prophylaxis of postoperative infections. The mean total volume of the exudate from postoperative wounds in these patients was 96.3 +/- 77.81 ml on Day 1, 14.6 +/- 17.1 ml on Day 2, 17.2 +/- 14.3 ml on Day 3, 32.0 +/- 17.0 ml on Day 4 and 34.0 ml (n = 1) on Day 5 of the postoperative period, and their CPZ level was, respectively 31.3 +/- 16.3, 31.2 +/- 19.4, 15.0 +/- 7.04, 13.4 +/- 6.78, and 2.45 micrograms/ml (n = 1), respectively with the level exceeding 30 micrograms/ml on Day 2 of the postoperative period and gradually decreasing thereafter. Recovery of CPZ during this period was 2941.1 +/- 2775.8 on Day 1, 375.3 +/- 445.9 on Day 2, 261.9 +/- 477.5 on Day 3, 371.4 +/- 10.5 on Day 4 and 83.3 micrograms (n = 1) on Day 5 of the postoperative period. In other words, of the total daily dose, 0.074, 0.009, 0.007, 0.009 and 0.002 appeared in the wound on Day 1, 2, 3, 4 and 5 of the postoperative period, respectively. Judging from the daily changes in the level of CPZ in the exudate and from the clinical results that all cases except one responded to this drug, it is evident that CPZ is highly useful for prophylaxis of postoperative infections, particularly for prophylaxis of infections of the postoperative wounds.

Adolescent↗