Contralateral transcondylar approach for aneurysms of the posterior inferior cerebellar artery-vertebral artery complex

We report a patient with an aneurysm of the left vertebral artery (VA)-posterior inferior cerebellar artery (PICA) complex that was treated successfully via a contralateral transcondylar approach. The aneurysm was small, pointed laterally to the right, and was located across the midline just above the level of the foramen magnum. This unusual location required special consideration during diagnostic evaluation and surgical planning. To simulate the operative view, the patient's head was turned 45 degrees. This extreme oblique view offered useful information with respect to the choice of side from which the surgical approach should be made. Removal of the posteromedial part of the occipital condyle allowed us to clip the aneurysmal neck without difficulty although the surgical approach was made on the side contralateral to the parent artery. We conclude that the contralateral approach for VA-PICA aneurysms should be considered when aneurysms cross the midline, and that extradural removal of the basal bony structures, including the occipital condyle, can provide a wide wirking space without excessive retraction on the brain stem.

Effects of edaravone on experimental brain injury in view of free radical reaction

The purpose of this study is to clarify the influence of a novel free radical scavenger edaravone on experimental brain injury. Male Wistar rats were anesthetized with 1-2% halothane. Brain injury was produced using a controlled cortical impact injury device. Experimental rats were divided into 2 groups. In the edaravone group, edaravone (3 mg/kg) was twice administered intravenously for 30 minutes. In the saline group, saline solution was administered in the same way. This administration of edaravone or saline solution made it possible to evaluate the relative effects of edaravone by assessment of free radical reaction and water content. As a result, the level of oxygen free radicals at 50 minutes after brain injury was significantly lower in the edaravone group than in the saline group. The water content in the injured brain at 180 minutes was significantly lower in the edaravone group than in the saline group. Therefore, we propose that edaravone may be effective for treatment in head injury.

Survey of antibiotic resistance in Pseudomonas aeruginosa by The Tokyo Johoku Association of Pseudomonas Studies

Pseudomonas aeruginosa resistance (minimum inhibitory concentration [MIC], > or =16 microg/ml defined as resistant) to meropenem, imipenem, panipenem, piperacillin, ceftazidime, cefozopran, cefoperazone, sulbactam/cefoperazone, amikacin, and tobramycin, as well as cross-resistance profiles, were investigated in P. aeruginosa strains isolated at eight hospitals in the Johoku area, Tokyo, during November 1998. Overall, 8.3% of isolates were imipenem-resistant and 4.6% were ceftazidime-resistant. However, the incidence of antibiotic-resistant P. aeruginosa was distinctly different at each hospital. P. aeruginosa resistance to imipenem ranged from (MIC) 1 to 64 microg/ml (MIC90 32 microg/ml), and its resistance to ceftazidime ranged from 2 to more than 128 microg/ml (MIC90, 64 microg/ml). Meropenem (MIC range, < or =0.25 to 16 microg/ml) was more active than panipenem (MIC range, 2 to 64 microg/ml). Cefozopran was more active than piperacillin, cefoperazone, or sulbactam/cefoperazone, but many strains were resistant to cefoperazone (17/57). Our analysis found cross-resistance to many beta-lactams, but the degree of cross-resistance was very variable.

Risk factors and predictors of coronary arterial lesions in Japanese hypertensive patients

The morbidity rate of coronary artery disease has recently increased in Japan. This is attributable to changes from traditional to more westernized lifestyles. In this study, we therefore examined the risk factors and predictors of coronary arterial lesions in Japanese patients with essential hypertension. Coronary angiography was performed in 109 consecutive essential hypertension patients (57 men and 52 women; 66 +/- 8.0 years of age) with either angina pectoris or atypical chest pain, who were chosen from 485 consecutive hypertensive patients in a hypertension clinic in Sendai, Japan. Coronary arterial stenosis of greater than 50% was defined as significant and used as a dependent variable for the multiple regression analysis. Risk factors were defined as factors confirmed to have a causal relationship with coronary arterial lesions, whereas arteriosclerotic complications and hypertensive target organ damage were defined as predictors. Multiple logistic regression analysis was performed using these parameters as independent variables. Of 109 patients, 25 had a coronary arterial stenosis greater than 50%. A smoking habit (odds ratio (OR): 4.48; 95% confidence interval (CI): 1.13-17.82; p<0.05), hypercholesterolemia (OR: 5.34; 95% CI: 1.52-18.73; p<0.05), and 24-h diastolic blood pressure (OR: 2.33; 95% CI: 1.06-5.16; p<0.05) were significant risk factors, whereas carotid intima-media thickness (OR: 5.85; 95% CI: 1.48-23.2; p<0.05) was a significant predictor of coronary arterial lesion. When two of the major risk factors (a smoking habit, hypercholesterolemia, or impaired glucose tolerance including diabetes mellitus) were clustered in addition to the hypertension, the risk of coronary arterial lesions increased by 6.7 to 10.1 times. These findings indicate that the major risk factors established in Caucasians, i.e., a smoking habit, hypercholesterolemia and blood pressure level, are also risk factors for coronary arterial lesions in Japanese with essential hypertension. The presence of two or more risk factors increases the risk of coronary arterial lesions synergistically in the presence of hypertension.

Differential stereoselective pharmacokinetics of pantoprazole, a proton pump inhibitor in extensive and poor metabolizers of pantoprazole--a preliminary study

Pantoprazole (PAN) is a proton pump inhibitor that is administered as a racemic mixture. The pharmacokinetics of PAN enantiomers were investigated in extensive metabolizers (EMs) and apparent poor metabolizers (PMs) of PAN who received a single, 40, 60, or 80 mg oral dose of racemic PAN as enteric-coated formulation. In the EMs, the serum concentrations of (-)-PAN were slightly higher than those of (+)-PAN at each dose level. The (+)/(-) ratios for the area under the concentration-time curve (AUC) and the half-life were 0.58-0.89 and 0.62-0.88, respectively. In the PMs, the serum concentrations and both enantiomers were much higher than those in the EMs at each dose level and significant differences in pharmacokinetics of (+)- and (-)-PAN were observed. The half-lives for (+)-PAN were 2.67-3.77 times longer than those for (-)-PAN. The AUCs for (+)-PAN were 2.65-3.45 times greater than those for (-)-PAN. Therefore, the metabolism of (+)-PAN is impaired to a greater extent than (-)-PAN in the PMs, which resulted in the stereoselective disposition of PAN in the PMs. It has been suggested that the EMs and the PMs of PAN could be differentiated by determining the (+)/(-) enantiomer ratio in serum at one time point, possibly 2-6 h after oral dosing, because the (+)/(-) enantiomer ratios in the PMs were opposite those in the EM subjects.

Recurrent craniopharyngioma with nasopharyngeal extension

We report the case of a 10-year-old boy having a recurrent craniopharyngioma with nasopharyngeal extension during a course of growth hormone therapy, in whom the nasopharyngeal craniopharyngioma was totally resected despite its extensive growth by using a transbasal approach. There has been no evidence of recurrence during 6 years of follow-up. A literature review was made with respect to nasopharyngeal extension of craniopharyngiomas, and the efficacy of the transbasal approach for those tumors is discussed.

Effect of HSR-903, a new fluoroquinolone, on the concentration of theophylline in serum

The effect of HSR-903, a new fluoroquinolone, on the concentration of theophylline in serum in healthy male volunteers was investigated. The concentration of theophylline in serum and the urinary excretion rates of theophylline on day 5 of concomitant dosing with HSR-903 tended to increase compared to those on day 4, when theophylline was given alone; however, the urinary excretion rates of 1-methyluric acid and 3-methylxanthine on day 5 of concomitant dosing with HSR-903 tended to decrease in comparison to those on day 4, when theophylline was given alone.

[A trial case of coronary bypass surgery under heart beat in a patient with severe functional disorders of kidney]

Coronary artery bypass grafting (CABG) was performed under heart beat without conducting extracorporeal circulation in a patient with severe functional disorders of kidney, and satisfactory results were attained. The patient was a 71-year-old male with past history of severe functional disorders of kidney and cerebral infarction. He had triple-vessel disease. First, CABG was performed for the primary branches under heart beat without adopting extra-corporeal circulation, then later, percutaneous transluminal coronary angioplasty (PTCA) was performed for the residual lesions, which lead to complete revascularization without causing aggravation of cerebral infarction or functional disorders of kidney or subjective symptoms such as chest pain. CABG conducted under heart beat is less aggressive not only to myocardium but to other important organs, and is thought to be effective for patients who have severe concurrent diseases to which extracorporeal circulation is likely to entail risks. Furthermore, concurrent therapy with PTCA is thought to expand the scope of application of CABG under heart beat including the cases of multiple-vessel diseases.

Interaction of citrus juices with pranidipine, a new 1,4-dihydropyridine calcium antagonist, in healthy subjects

OBJECTIVES

The study was conducted to investigate whether oral co-administration with citrus juices significantly affects the pharmacokinetics and/or pharmacodynamics of pranidipine, a new 1,4-dihydropyridine calcium antagonist, in healthy male subjects. Grapefruit juice and orange juice, which were both commercially available, were used in this study.

METHODS

Sixteen healthy male Japanese subjects participated in this study and were divided into two groups for grapefruit juice and orange juice treatment. The study followed an open-labelled crossover design, comparing the effects of a single oral dose of 2 mg pranidipine taken together with 250 ml citrus juice or 250 ml water. Serum pharmacokinetics of pranidipine, adverse reactions, blood pressure, heart rate, 12-lead ECG, haematology, clinical chemistry and urinalysis were measured throughout the study.

RESULTS

For grapefruit juice, mean Cmax and AUC0-24 h were significantly higher than those of water (P=0.0003 and 0.0005, respectively, ANOVA) with the ratios of log transformed values being 1.50 and 1.74, respectively. There were no differences in tmax and t1/2 between the juice and water treatments. A significant increase in heart rate (P=0.0240, ANOVA with repeated measurements) was observed in the juice treatment whereas there were no significant differences in systolic and diastolic blood pressure between the two treatments. For orange juice, a small decrease in mean Cmax was observed compared with water (P=0.0218, ANOVA) with the ratio being 0.86, but there was no significant difference in AUC0-24h between the two treatments. No marked differences were observed in tmax and t1/2. Oral pranidipine administration with orange juice did not affect heart rate, systolic and diastolic blood pressures or other parameters for safety evaluation.

CONCLUSIONS

Oral co-administration with grapefruit juice and pranidipine was associated with increased bioavailability and changed the pharmacodynamics of pranidipine, particularly with regard to heart rate. Orange juice intake with pranidipine did not markedly affect the pharmacokinetics and no clinically significant changes were observed in the pharmacodynamics and safety evaluation.

Functional roles of phenylalanine(7) of thymic humoral factor-gamma 2 in the impaired blastogenic response of uremic T-lymphocytes

The peptide analogs of thymic humoral factor-gamma 2 (THF-gamma 2) in which phenylalanine residue at the 7th position are replaced by phenylglycine (Phg), homophenylalanine (Hph), and 1-naphthylalanine (1-Nal) were synthesized by a solid-phase method and the immunological significance of the aromatic amino acid of this position was comparatively investigated. The in vitro restoring effect of the synthetic peptides on the impaired phytohemagglutinin (PHA) response of T-lymphocytes from uremic patients was tested. The observed activities of these peptides were in order (1-Nal7) thymic humoral factor [THF]-gamma 2 > 4-Fluoro (Phe7) THF-gamma 2 > THF-gamma 2. However, the other two analogs, [Phg7] THF-gamma 2 and [Hph7] THF-gamma 2, had no restoring effect even at a higher concentration.

[A case of sellar T cell type malignant lymphoma]

A case of primary T cell type malignant lymphoma of the sellar region was reported. This 53-year-old male was admitted to our neurosurgical service because of slowly progressive occipitalgia and diplopia over the previous 5 months. On admission neurological examination revealed a slight limitation of the lateral movement of the left eye. Endocrinological examination showed no abnormalities. Despite a mild neurological deficit, a CT scan revealed an extensive bony destruction around the sellar region including the dorsum sellae, the bilateral petrous apices, and the upper two thirds of the clivus. Magnetic resonance imaging (MRI) disclosed that the tumor was slightly hypointense on T1-weighted image, isointense on T2-weighted image, and faintly and homogeneously enhanced after administration of Gd-DTPA. Since the tumor was enhanced faintly on MRI, it was diagnosed as an invasive pituitary adenoma, but it was thought that chordoma and germinoma should be considered. The patient underwent a transsphenoidal surgery. A firm, grayish and avascular tumor was partially removed. The histopathological examination using monoclonal surface marker of the specimen revealed the tumor was stained with UCHL-1 and CD3 antibodies directed against T cells, and diagnosed as T cell type malignant lymphoma of the sellar region (diffuse, large cell type; LSG). Postoperatively he received radiation therapy. His symptoms much improved and no regrowth of the residual tumor has been found in follow-up studies to the present. Primary malignant lymphomas very rarely occur in the skull base. As far as we are aware, this is the only second case of primary T-cell lymphoma in the sellar region reported so far in the medical literature. Although preoperative diagnosis is extremely difficult because of a paucity of data, malignant lymphomas should be kept in mind in the differential diagnosis of sellar tumors, especially if neuroimaging studies show an extensive bony destruction in the skull base.

Comparison of the effects of acarbose and voglibose in healthy subjects

Acarbose and voglibose are alpha-glucosidase inhibitors. Although the pharmacologic effects and incidence of abdominal adverse events associated with the two drugs have been reported to differ, no study has directly compared acarbose and voglibose. To compare the pharmacologic effects and gastrointestinal adverse events associated with the two drugs, a randomized, placebo-controlled, double-masked, fivefold crossover study was performed in 20 healthy male subjects. To assess the pharmacologic effects, plasma immunoreactive insulin (IRI), plasma glucose, and 24-hour urinary connecting-peptide immunoreactivity (CPR) excretion were measured. Although the postprandial increase in plasma glucose level was reduced significantly with both acarbose and voglibose, the rate of reduction was small. The maximum concentration (Cmax) and area under the plasma concentration-time curve (AUC) of plasma IRI after meals decreased significantly with all treatments except voglibose 0.3 mg compared with placebo. Overall, the Cmax and AUC of plasma IRI decreased more when subjects received acarbose than voglibose. Urinary CPR excretion decreased by 30.6% and 41.7%, respectively, in subjects who received acarbose 50 mg or 100 mg compared with the previous day when no drug was given, whereas the urinary CPR excretion did not decrease significantly with voglibose. There was no significant difference in the frequency of gastrointestinal adverse events between groups, including the placebo group. One-day administration of acarbose and voglibose at currently recommended clinical doses demonstrated that acarbose was more effective in sparing endogenous insulin secretion than was voglibose.

Differential stereoselective pharmacokinetics of pantoprazole, a proton pump inhibitor in extensive and poor metabolizers of pantoprazole--a preliminary study

Pantoprazole (PAN) is a proton pump inhibitor that is administered as a racemic mixture. The pharmacokinetics of PAN enantiomers were investigated in extensive metabolizers (EMs) and apparent poor metabolizers (PMs) of PAN who received a single, 40, 60, or 80 mg oral dose of racemic PAN as enteric-coated formulation. In the EMs, the serum concentrations of (-)-PAN were slightly higher than those of (+)-PAN at each dose level. The (+)/(-) ratios for the area under the concentration-time curve (AUC) and the half-life were 0.58-0.89 and 0.62-0.88, respectively. In the PMs, the serum concentrations and both enantiomers were much higher than those in the EMs at each dose level and significant differences in pharmacokinetics of (+)- and (-)-PAN were observed. The half-lives for (+)-PAN were 2.67-3.77 times longer than those for (-)-PAN. The AUCs for (+)-PAN were 2.65-3.45 times greater than those for (-)-PAN. Therefore, the metabolism of (+)-PAN is impaired to a greater extent than (-)-PAN in the PMs, which resulted in the stereoselective disposition of PAN in the PMs. It has been suggested that the EMs and the PMs of PAN could be differentiated by determining the (+)/(-) enantiomer ratio in serum at one time point, possibly 2-6 h after oral dosing, because the (+)/(-) enantiomer ratios in the PMs were opposite those in the EM subjects.

[A chronic encapsulated expanding hematoma with cyst formation caused by rupture of arteriovenous malformation: a case report]

A 57-year-old male was admitted to our hospital complaining of a headache with disturbance of consciousness on November 7, 1994. CT scans revealed an intracerebral hematoma of 25ml in volume in the left frontal lobe with adjacent spotty calcification. An arteriovenous malformation (AVM) with a nidus of 2.0 x 2.0cm in size was found to be the cause of the hematoma by cerebral angiography. Since the patient complained of mild right hemiparesis 10 days after the onset, CT scans were taken and a slightly enlarged hematoma with capsule formation was observed. On the 31st day after the onset, the hematoma had liquefied and the surrounding capsule was clearly visible on CT. Since the patient's only symptom was a slight headache, and he displayed no other serious conditions, a palliative operation was planned. The AVM was removed and the capsule was resected 41 days after the onset. The capsule or cyst wall of the liquefied hematoma was composed of three layers: a granulation layer with a neovascular system on the inside, a collagenous layer in the middle, and a reactive brain tissue layer on the outside. The structure of the capsule was the same as the structure of the cyst wall in chronic hematomas that have been reported as cystic AVM or encapsulated expanding hematoma in the literature. We would therefore like to propose that chronic encapsulated expanding hematomas form with time due to intermittent bleeding or exudation form the neovascular system of a cyst wall.

Functional roles of Phe of deacetyl-thymosin beta4 in the impaired blastogenic response of uraemic T-lymphocytes

Phe¹² of deacetyl-thymosin β₄ is one of the structural essentials for restorative effect on the impaired blastogenic response of uraemic T-lymphocytes. In order to evaluate the functional roles of this phenyl group in the restorative effect on impaired T-lymphocytes, two analogues, [1- Nal¹²]deacetyl-thymosin β₄ and [Cha¹²]deacetyl4 thymosin β₄, were synthesized by a solid-phase method and evaluated for restorative effect on the impaired blastogenic response of uraemic T-lymphocytes. The results indicated that [1-Nal¹²]deacetyl-thymosin β₄ which had a bulky naphthyl ring showed a stronger restorative effect than that of deacetyl-thymosin β₄, but it was slightly weaker than that of [Phe(4F)¹²]deacetyl-thymosin β₄. However, [Cha¹²]deacetyl-thymosin β₄ showed no restorative effect on the impaired blastogenic response of uraemic T-lymphocytes.

Pharmacokinetics and tolerance of pantoprazole, a proton pump inhibitor after single and multiple oral doses in healthy Japanese volunteers

The pharmacokinetics and tolerance of pantoprazole were investigated after single (20, 40, 80, and 120 mg) and multiple (80 mg once a day for 7 days) oral administration as enteric-coated tablet formulation to healthy male Japanese volunteers. Pantoprazole was well tolerated with no serious adverse events at all doses. Pantoprazole was rapidly absorbed in the fasted state. The mean maximum concentration in serum (Cmax) ranged from 1.77-9.25 micrograms/ml for the 20-120 mg dose and the mean time to reach Cmax (tmax) ranged from 1.92-2.42 h. The half-life (t1/2) ranged from 0.74-1.16 h. A good linear correlation was found between the administered doses (20-120 mg) and the resulting area under the concentration-time curve (AUC) and Cmax with the correlation coefficients of 0.9088 and 0.9263, respectively. Within 24 h, pantoprazole was excreted into urine as the unchanged drug to a negligible extent. In the multiple dose study, 2 apparent poor metabolizers (PMs) of pantoprazole were observed. The means of Cmax, AUC and t1/2 for these 2 PMs were 1.6, 6.7, and 6.8 times higher than those of the extensive metabolizers (EMs). The pharmacokinetic parameters such as Cmax, AUC, and t1/2 after the 7th oral dose were not significantly different from those after the 1st dose both in the PMs and the EMs, which indicated that there was virtually no drug accumulation.

A surgical technique to avoid postoperative enophthalmos in the cranioorbital approach. Technical note

The authors describe a surgical technique to avoid postoperative enophthalmos when using the cranioorbital approach. To perform osteotomies with a less demanding technique, two separate bone flaps were created: 1) a free frontotemporal bone flap and 2) en bloc removal of the superior and lateral orbital rims: Because the latter bone flap includes both the orbital roof and the posterolateral wall of the orbit with the greater wing of the sphenoid bone, unnecessary bone defects in the lateral orbital wall are avoided. The technique has been performed in seven patients treated for medially located skull base neoplasms or complex anterior circulation aneurysms without postoperative enophthalmos or other cosmetic problems. The authors believe this cranioorbital approach, with its simpler, less invasive surgical technique, offers a definite advantage by avoiding postoperative enophthalmos.

[Outcome of long-term nasal intermittent positive pressure ventilation in 41 patients with hypercapnic respiratory failure]

Nasal intermittent positive pressure ventilation (NIPPV) is widely used in domiciliary treatment of chronic ventilatory disorders. The outcomes of long-term NIPPV were analyzed in 41 patients with hypercapnic respiratory failure due to pulmonary tuberculosis sequelae (PTS; n = 17), neuromuscular disease (NMD; n = 8), kyphoscoliosis (KS; n = 7), chronic obstructive pulmonary disease (COPD; n = 6), and miscellaneous diseases (n = 3). Twenty-seven patients with chronic conditions but without acute exacerbations began receiving NIPPV, and fourteen patients began receiving NIPPV after an acute exacerbation. Outcome measures included the probability of continuing NIPPV, survival after starting NIPPV, survival after starting home oxygen therapy (HOT), arterial blood gases, nocturnal oxygen saturation, pulmonary function, and the number of hospital days. Two patients with PTS died, 7 and 40 months after starting NIPPV. Two patients (one with PTS and one with COPD) switched from NIPPV to intermittent positive pressure ventilation via a tracheostomy. The condition of one patient with NMD improved and NIPPV was discontinued. The three-year and five-year probabilities of continuing NIPPV in all patients were 82%, and 71%, respectively. The survival rates three and five years after starting NIPPV were 97% and 85%, respectively. The survival rates one to nine years, and ten to eleven years after starting HOT were 98% and 65%, respectively. The arterial PO2 and PCO2, nocturnal oxygen saturation, vital capacity, and forced expiratory volume, in one second all improved after NIPPV was begun. NIPPV also reduced the number of hospital days, particularly in patients with KS. In conclusion, the long-term outcome of NIPPV in patients with hypercapnic respiratory failure is encouraging.

Syntheses and immunological effects of thymic humoral factor-gamma 2 and its Phe7-substituted analogues

Thymic humoral factor-gamma 2 and five analogues modified at position 7 with various phenylalanine derivatives were synthesized by a solid-phase method. The synthetic peptides were tested for their effects on the impaired blastogenic response of phytohemagglutinin-stimulated T lymphocytes of uremic patients with infectious diseases. The synthetic thymic humoral factor-gamma 2 enhanced the blastogenic response of T lymphocytes in the blood of the 2 patients tested. Of the synthetic peptides, [Phe(4F)7]thymic humoral factor-gamma 2 exhibited the most potent effect.

Indoxyl-beta-D-glucuronide and 3-indoxyl sulfate in plasma of hemodialysis patients

The content of indoxyl-beta-D-glucuronide, which has been found in patients' plasma as a new indicator of renal failure, logarithmically correlated with that of 3-indoxyl sulfate (indican) in the plasma of hemodialysis patients, showing another weak correlation with beta(2)-microglobulin content. The content ratio of indoxyl-beta-D-glucuronide to 3-indoxyl sulfate (IG/IS) gradually increased depending on the duration of hemodialysis treatment. Indoxyl-beta-D-glucuronide could be easily dialyzed in the hemodialysis treatment, in contrast to hardly dialyzable 3-indoxyl sulfate which bound to plasma proteins. Therefore, glucuronide conjugation in indole excretion is favorable for hemodialysis patients in that it eliminates indoxyl compounds in blood by hemodialysis.

Spinal arachnoid cyst developing after surgical treatment of a ruptured vertebral artery aneurysm: a possible complication of topical use of fibrin glue. Case report

A case is reported of a 59-year-old man with a spinal arachnoid cyst accompanied by spinal arachnoiditis. The patient developed symptoms after treatment for a ruptured vertebral artery aneurysm, in which fibrin glue was used for reconstruction of the suboccipital bone defect. It is believed that the fibrin glue may have played a role in forming the arachnoid cyst. The authors urge the readers to keep in mind the possibility of subclinical spinal arachnoiditis in the patients with aneurysmal subarachnoid hemorrhage and suggest that care should be taken to avoid any possible adverse effect of fibrin glue.

Synthesis of [Phe(4F)3]thymopoietin II and examination of its immunological effect on the impaired blastogenic response of T-lymphocytes of uremic patients

[Phe(4F)3]thymopoietin II was synthesized using a conventional solution method. The deprotection of the protected [Phe(4F)3]thymopoetin II was achieved by treatment with 1 M trifluoromethanesulfonic acid:thioanisole (molar ratio 1:1) in trifluoroacetic acid in the presence of dimethylselenide and m-cresol. The synthetic f1p4(4F)3]thymopoietin II and thymopoietin II were tested for effect on impaired T-lymphocyte transformation by phytohemagglutinin in uremic patients suffering from recurrent infectious diseases. The restoring activity on the impaired phytohemagglutinin stimulation of T-lymphocytes was obtained after incubation of peripheral lymphocytes isolated from uremic patients with the synthetic [Phe(4F)3]thymopoietin II. This peptide exhibited far stronger restoring effect than that of our synthetic thymopoietin II.

[Recurrence of pleomorphic xanthoastrocytoma six years after total removal of mural nodule: a case report]

A case of recurrent pleomorphic xanthoastrocytoma (PXA) was reported. A 46-year-old male underwent total removal of mural nodule from cystic tumor in the left temporal lobe in 1986. Histological diagnosis was astrocytoma. There were no abnormal neurological signs or symptoms after the operation. However, 6 years after the operation he complained of strong unpleasant smell as of rotten onions and was admitted to our hospital. MRI revealed a cystic tumor with a mural nodule which was enhanced markedly by Gd-DTPA in the same location as previous tumor site. He was operated upon again and tumor was removed with the cyst wall. Histological diagnosis was PXA. Surgical procedures for removal of cystic PXA has been controversial; removal of tumor only, tumor removal with biopsy of cyst wall, or tumor removal with resection of cyst wall. Real reason for recurrence of this tumor in our case is unknown. However, since astrocytoma cells were found in the biopsy specimen of the cyst wall at time of the first operation, the tumor might have recurred from these cells. Therefore, this time we removed not only the mural nodule but also the cyst wall, because the cyst wall peeled off easily. We would like to propose that PXA cyst walls should be resected, whenever possible, in order to accomplish total removal of tumor.

Recombinant human erythropoietin stimulates tubular reabsorption of sodium in anesthetized rabbits

To determine whether recombinant human erythropoietin (rHuEPO) exerts a direct vasoconstrictive effect on renal arteries or affects renal function, we measured renal hemodynamics and renal function during a 30-min intrarenal infusion of rHuEPO in anesthetized rabbits without renal failure. Intrarenal infusion of rHuEPO at a rate of 100 U/min did not alter mean arterial pressure, renal blood flow, or renal vascular resistance, as compared with controls treated with vehicle. There were no significant rHuEPO-associated changes in glomerular filtration rate, filtration fraction, or arterial hematocrit. However, urine volume, urinary excretion of sodium and potassium, and fractional sodium excretion were significantly reduced by intrarenal infusion of rHuEPO. These observations indicate that rHuEPO has no direct effects on mean arterial pressure or renal hemodynamics, but that it stimulates net tubular sodium reabsorption, and reduces urine volume and urinary excretion of sodium and potassium in anesthetized rabbits without renal failure.

Pressor effect of recombinant human erythropoietin: results of ambulatory blood pressure monitoring and home blood pressure measurements

We investigated whether treatment of anemic hemodialysis patients with a low dose of recombinant human erythropoietin (erythropoietin) for a short period would increase their blood pressure. Ambulatory blood pressure monitoring and home blood pressure measurements were used to detect minute increase in blood pressure. Thirty-two patients with a hematocrit of 25% or less received erythropoietin at the dose of 4500 IU/week, by the intravenous route for 8 weeks. Erythropoietin increased the hematocrit from 20.9 +/- 2.1 to 26.2 +/- 2.1%. Erythropoietin elevated mean ambulatory blood pressure by 5 mmHg or more in two-thirds of patients (n = 20; pressor group), while it elevated home mean blood pressure by 5 mmHg or more in one-third of patients (n = 11). An increase in clinic mean blood pressure by more than 5 mmHg was observed only in one-fourth of patients (n = 7). Circadian variation of blood pressure (nocturnal fall and diurnal rise) had been attenuated in the patients of the pressor group before erythropoietin treatment and erythropoietin decreased the nocturnal fall of blood pressure further more. Erythropoietin elevated nocturnal blood pressure more than diurnal blood pressure. Therefore, the increase in blood pressure induced by erythropoietin was detected more reliably by ambulatory blood pressure monitoring. There was no relation between the change in hemoglobin concentration and the increase in ambulatory blood pressure induced by erythropoietin. Erythropoietin tended to decrease cardiac output and plasma volume while it increased total peripheral resistance. It also decreased plasma norepinephrine and vasopressin levels but did not affect other humoral factors. Although the pressor effect of erythropoietin treatment for 8 weeks at the dose of 4500 IU/week was not evident on clinic blood pressure measurements, any increase in blood pressure determined by ambulatory blood pressure should be treated carefully to reduce the risk of a cardiovascular complication in patients receiving hemodialysis.

Muscle cramps and elevated serum creatine phosphokinase levels induced by beta-adrenoceptor blockers

We have assessed the propensity of beta-adrenoceptor blockers to cause muscle cramps and to raise the serum creatine phosphokinase (CPK) level in 78 patients with essential hypertension. After a control period, a beta-adrenoceptor blocker without intrinsic sympathomimetic activity (ISA; propranolol, metoprolol or arotinolol) was administered for three months. Thereafter, the patients were randomised to receive a beta-adrenoceptor blocker with ISA (pindolol or carteolol) for three months or a beta-adrenoceptor blocker without ISA for a further three months. This pattern was continued until all beta-adrenoceptor blockers had been given. At the end of each period, CPK and CPK-MB levels were measured. Of the 78 subjects, muscle cramps occurred in 27 during treatment with pindolol and 32 during treatment with carteolol. No complaints were made by subjects treated with propranolol and arotinolol, but muscle cramps were reported in 2 treated with metoprolol. While muscle cramps were caused both by pindolol and carteolol in 16 subjects, they were caused by either of these drugs in the remainder of the subjects. Muscle cramp occurred mainly in the calves when the patients were in bed at night. Serum CPK and CPK-MB levels increased significantly during treatment with pindolol (control period vs pindolol, CPK = 96 vs 133 IU.ml-1, CPK-MB = 14 vs 18 IU.ml-1) or carteolol (CPK = 117 IU.ml-1, CPK-MB = 18 IU.ml-1) while the levels during treatment with propranolol, arotinolol and metoprolol did not change from those in the control period.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of graded calcium infusions on rhythmic blood pressure oscillations in normal man

This study was designed to determine whether calcium contributes to the regulation of rhythmic oscillations in blood pressure. Six normal subjects received sequential 1-h infusions of calcium gluconate (1.5, 3.0 and 4.5 mg calcium/kg/h) during continuous blood pressure (Finapres) monitoring. The plasma ionized calcium ([Ca2+]) concentration increased from 4.6 +/- 0.07 mg/dl to 5.97 +/- 0.20 mg/dl (p < 0.01) with infusion. The mid-frequency (0.07-0.14 Hz, Mayer wave) power spectrum of diastolic blood pressure was depressed slightly following the first dose but increased significantly following the final dose (p < 0.05). The high-frequency (0.15-0.40 Hz) power spectrum of systolic blood pressure decreased following the first dose (p < 0.05) and subsequently remained low. The low-frequency (0.02-0.6 Hz) power spectrum was not affected. These results demonstrate that graded hypercalcaemia affects blood pressure oscillations in man. Our data suggest that the amplitude of the Mayer wave, a clinical marker of sympathetic vascular tone, is modulated in part by calcium.

Compliance with long-term dietary salt restriction in hypertensive outpatients

Eighty hypertensive outpatients were recruited for a dietary salt restriction program to examine long-term compliance. Twenty-four-hour urine samples were collected repeatedly (7.9 +/- 2.6 times, mean +/- s.d.) during a follow-up period of 6.4 +/- 1.7 years. After initial urine collection, nutritional education was carried out by dietitians to reduce dietary salt intake to 8 g/day or less. After every urine collection, the subjects were given advice by doctors on salt restriction, if necessary. The mean 24-hour urinary salt excretion (U-NaCl) and the mean urinary salt/creatinine ratio (U-NaCl/U-Cr) varied considerably both among and within individuals. U-NaCl/U-Cr, but not U-NaCl, in females was significantly higher than that in males, and in middle-aged subjects than in young subjects. U-NaCl and U-NaCl/U-Cr tended to decrease in the summer. In spite of the repeated educational effort, neither U-NaCl nor U-NaCl/U-Cr was different in the first control samples from that in the last samples. When 57 subjects were divided into three groups according to the urinary salt excretion level, U-NaCl was consistently higher during a follow-up period in the high-salt excretion group than in the mid-salt excretion group, while U-NaCl in the low-salt excretion group was initially lower than, but finally similar to, that in the mid-salt excretion group. These results suggest that: (1) multiple 24-hour urine samplings are required to assess urinary salt excretion in individuals; (2) the influence of age and sex should be taken into account in interpreting U-NaCl/U-Cr; and (3) it seems difficult to achieve long-term dietary salt restriction as a non-pharmacologic treatment of hypertension in an outpatient clinic.

Ultrasonic diagnosis of renal cell carcinoma in hemodialysis patients

From April 1985 to December 1992 abdominal ultrasonic examination was performed in 1,603 hemodialysis patients at our hospital. Renal cell carcinoma was found in 41 patients (2.6%), confirmed by nephrectomy as well as histology. This rate was 32 times greater than that of the general population (22 patients with renal cell carcinoma were detected among 27,933 at our health care center). Renal cell carcinoma was found in 18 patients with a contracted kidney, 19 with acquired cystic disease of the kidney and 4 with a native kidney after renal transplantation. Among 19 patients with acquired cystic disease of the kidney 8 had unilateral multiple tumors and 5 bilateral multiple tumors. The detection rate of renal cell carcinoma was 100% by ultrasonography, 67% by computerized tomography and 56% by angiography. Ultrasonography was the most accurate examination for the diagnosis of renal cell carcinoma in hemodialysis patients.

Synthesis of an immunologically active analog of thymic humoral factor-gamma 2 with enhanced enzymatic stability

Acetyl-thymic humoral factor-gamma 2 chloromethyl ketone [Ac-Leu-Glu-Asp-Gly-Pro-Lys-Phe-Leu-CH2Cl], an analog of thymic humoral factor-gamma 2, was synthesized and studied for its immunological effects on the impaired blastogenic response of T-lymphocytes isolated from uremic patients. Synthetic thymic humoral factor-gamma 2 and the synthetic acetyl-thymic humoral factor-gamma 2 chloromethyl ketone both restored the impaired blastogenic response of T-lymphocytes of uremic patients. However, the synthetic thymic humoral factor-gamma 2 is susceptible to proteolytic digestion. On the other hand, the synthetic acetylthymic humoral factor-gamma 2 chloromethyl ketone retained activity and was shown to exhibit a high degree of stability when incubated in human serum, These results indicate that N-terminal acetylation and the introduction of a chloromethyl ketone residue into the C-terminal residue of thymic humoral factor-gamma 2 increase resistance to proteolytic degradation by exopeptidases without loss of immunological activity.

Indoxyl-beta-D-glucuronide, the primary emitter of low-level chemiluminescence in plasma of hemodialysis patients

Characteristic light emission induced by the oxidation of hydroxyl radicals has been found in plasma of hemodialysis patients (Agatsuma et al., Clin Chem 1992;38:48-55). We purified a primary emitter, a chemiluminescent component peaking at 430 nm, by anion-exchange chromatography and reversed-phase HPLC. By using proton nuclear magnetic resonance and authentic indoxyl compounds, we determined the primary emitter to be indoxyl-beta-D-glucuronide. Absorption and fluorescence spectra of the purified sample coincided well with those of authentic indoxyl-beta-D-glucuronide, as did the peak in the chemiluminescence emission spectrum. Retention time of the purified sample on reversed-phase HPLC, measured by fluorescence, was also in accordance with that of indoxyl-beta-D-glucuronide. To our knowledge, this is the first identification of a primary emitter of low-level chemiluminescence from a biological source.

Indoxyl-beta-D-glucuronide, the primary emitter of low-level chemiluminescence in plasma of hemodialysis patients

Characteristic light emission induced by the oxidation of hydroxyl radicals has been found in plasma of hemodialysis patients (Agatsuma et al., Clin Chem 1992;38:48-55). We purified a primary emitter, a chemiluminescent component peaking at 430 nm, by anion-exchange chromatography and reversed-phase HPLC. By using proton nuclear magnetic resonance and authentic indoxyl compounds, we determined the primary emitter to be indoxyl-beta-D-glucuronide. Absorption and fluorescence spectra of the purified sample coincided well with those of authentic indoxyl-beta-D-glucuronide, as did the peak in the chemiluminescence emission spectrum. Retention time of the purified sample on reversed-phase HPLC, measured by fluorescence, was also in accordance with that of indoxyl-beta-D-glucuronide. To our knowledge, this is the first identification of a primary emitter of low-level chemiluminescence from a biological source.

Syntheses and immunological effects of thymic humoral factor-gamma 2 and its Phe7-substituted analogues

Thymic humoral factor-gamma 2 and five analogues modified at position 7 with various phenylalanine derivatives were synthesized by a solid-phase method. The synthetic peptides were tested for their effects on the impaired blastogenic response of phytohaemagglutin-stimulated T-lymphocytes of uraemic patients with infectious diseases. The synthetic thymic humoral factor-gamma 2 enhanced the blastogenic response of T-lymphocytes in the blood of the two patients tested. Of the synthetic peptides, [4-fluoro-Phe7]thymic humoral factor-gamma 2 exhibited the most potent effect.

Accuracy and performance of the Terumo ES-H51, a new portable blood pressure monitor

A high performance portable automatic sphygmomanometer, the Terumo ES-H51 (104 g, 58 x 22 x 92 mm), was newly developed for clinical use as a substitute for auscultation using a mercury sphygmomanometer. This device usually displays blood pressure (BP) values obtained by the Korotkoff sound method (K-method). However, when the device judges that BP values obtained by the K-method are inaccurate or unreliable, it substitutes automatically BP values obtained by the cuffoscillometric method (O-method). The accuracy and reliability of the device was tested by comparing it to the auscultation with the standard mercury sphygmomanometer. The mean difference between BP values obtained by the standard method and those obtained by the K-method were -0.7 +/- 2.9 mm Hg systole (mean +/- SD) and -0.3 +/- 2.6 mm Hg diastole, whereas the difference between the former and those obtained by the O-method were 0.3 +/- 5.7 mm Hg systole and 0.3 +/- 4.3 mm Hg diastole (n = 170). The agreement between the BP values obtained according to each of the two methods using the device and the standard method was within 5 mm Hg for 72% to 93% of both systolic and diastolic readings. Therefore, BP values measured by the ES-H51 are accurate. The ES-H51 is sufficiently small and light to be carried easily anywhere. The objective and reproducible BP information obtained by the present device would be useful in clinical practice.

[A case of intracerebral tuberculoma: clinical characteristics and MRI findings]

A case of intracerebral tuberculoma treated surgically was reported. A 47-year-old man was admitted to our hospital because of progressive left hemiaparesis over the previous 5 months. A computerized tomography scan showed a well enhanced mass associated with a marked perifocal edema. T1 weighted magnetic resonance imaging (MRI) revealed an isosignal ring around the heterogenous low intensity mass. A low intensity area just interior to this ring was also visualized both in T1 and T2 weighted images. Although the clinical course was unusually long, this was diagnosed as a metastatic brain tumor. He underwent a right frontal craniotomy and a well circumscribed, yellowish, firm mass was totally extirpated. Pathohistologically, this mass was considered to be a tuberculoma though the tuberculous bacilli could not be identified in Ziehl-Neelsen staining. His hemiplegia improved much and his ambulation was restored. Since tuberclomas are quite rare in developed countries, the diagnosis of intracerebral tuberculomas would be extremely difficult unless tuberculosis was verified in some other organs. The auxiliary examinations even by using MRI have often given little information which would assist diagnosis. However, based on pathological findings, the ring appearance and low intensity area medial to the ring in the outer part of the tuberculoma shown in MRI of our patient seemed to represent a chronic granulomatous inflammation and gave a clue to rule out the suspicion of metastatic brain tumors. To make a correct diagnosis of intracerebral tuberculomas, multidisciplinary consideration is mandatory.

Pressor effect of recombinant human erythropoietin: results of home blood pressure measurements in hemodialysis patients

We investigated whether the treatment of anemic hemodialysis patients with a low dose of recombinant human erythropoietin (rHEpo) for a short period would increase the blood pressure (BP). Home BP measurements were used to detect minute increases in BP. Fifty-one anemic patients on maintenance hemodialysis with a hematocrit of 25% or less received rHEpo at the dose of 4500 IU/week by the intravenous route for 8 weeks. Overall, rHEpo did not increase the BP whether measured at home or in the clinic (causal BP). Hemoglobin concentration increased significantly from 7.1 +/- 0.7 to 8.8 +/- 0.7 g/dl. Patients were classified into two groups according to the change in mean (M) home BP induced by rHEpo: a pressor group (delta MBP > or = 5 mmHg, n = 17) and a non-pressor group (delta MBP < 5 mmHg, n = 34). The hemoglobin concentration rose significantly in both groups, but there was no change in casual BP. Home blood pressure measurements showed a gradual and continuous rise in BP in the pressor group, but not in the non-pressor group. Patients administered antihypertensive medications before rHEpo treatment accounted for 88% of the former and 50% of the latter groups. Two patients with malignant nephrosclerosis were included in the pressor group. The findings indicate that rHEpo, even given at a low dose for a short period, elevates the BP, as determined by home BP measurement, but not by casual measurements obtained in the clinic.

[Ultrasonic diagnosis of renal cell carcinoma in hemodialysis patients]

Abdominal ultrasonic examination (US) was performed in 1556 patients on hemodialysis for 7 years and 6 months from April 1955 to September 1992. Renal cell carcinoma (RCC) proved histologically by operation was found in 36 patients (41 kidneys). Among the 36, RCC developed from the contracted kidney in 15, the individual kidney after renal transplantation in 3, and from ACDK (acquired cystic disease of the kidney) in 18. Among the 18 (ACDK), multiple tumors were found in the unilateral kidney in 8 and in bilateral kidney in 5. RCC was detected at the rate of 2.3% in patients on hemodialysis (1 out of 43). It was 29 time as high as in healthy persons (RCC was found in 22 out of 27933 at our Health Check-up Center, 0.079%). RCC was diagnosed 100% by US, 68% by CT, and 55% by angiography. US is the most excellent examination for the diagnosis of RCC in patients on hemodialysis.

[Long-term artificial ventilation by nasal intermittent positive pressure ventilation; 6 cases of domiciliary assisted ventilation]

Six patients with chronic respiratory failure associated with hypercapnia were treated with nasal intermittent positive pressure ventilation (NIPPV) at home. NIPPV was delivered via a custom molded nasal interface described by McDermott. The patients consisted of one patient with kyphoscoliosis, three with Tb-sequela, one with COPD, and one with neuromuscular disease. Each patient had been treated with oxygen therapy until assisted ventilation was initiated because of CO2 retention. NIPPV was administered using a volume cycled flow generator set to deliver a minute volume such that PaCO2 was maintained between 35 and 45 Torr on NIPPV trial performed during wakefulness under the condition of no leakage from the mask. Supplementary oxygen was added so that oxygen saturation was maintained above 90 percent during more than 95% of nighttime NIPPV. Arterial blood gas tensions during daytime spontaneous breathing showed an improvement (PaCO2 68.3 +/- 7.2 Torr, PaO2 70.4 +/- 15.5 Torr, SaO2 91.6 +/- 4.3% before treatment; PaCO2 55.8 +/- 4.7 Torr, PaO2 87.5 +/- 16.5 Torr, SaO2 95.5 +/- 1.7% on treatment, mean +/- SD). The duration of NIPPV at home ranged from 2 to 24 months (11.7 +/- 6.8), and there was no hospitalization due to exacerbation during this period. In conclusion, NIPPV via a custom molded mask is simple, noninvasive, and suitable for the provision of long-term and domiciliary assisted ventilation.

[A case of gliosarcoma associated with large cyst]

A case of gliosarcoma with a large cyst is reported. A 22-year-old female was admitted to our hospital with complaints of blurred vision and headache. Plain skull x-ray films showed a radiolucent area in the right frontal area. Computed tomography (CT) revealed an iso-dense mass in the right frontal lobe with a large cyst. After administration of contrast medium, the solid part and cyst wall were well enhanced and the content of the cyst was slightly enhanced. CT number of the cyst fluid was increased from 64.2 to 83.5 Hounsfield units, after administration of the contrast medium. Axial T1-weighted magnetic resonance image (MRI) revealed an iso-intense mass with marked enhancement by Gd-DTPA in the same area. A large cyst was shown to be located in the dorsal part of the mass. A small round protrusion, 10 mm in diameter, was found on the anterior portion of the mass on this MRI. Right carotid angiogram showed a tumor stain fed by the frontopolar artery. Right frontal lobectomy including the tumor was carried out with a preoperative diagnosis of glioblastoma. The patient received radiation therapy of 60Gy (whole brain 40Gy; focal 20Gy) and chemotherapy postoperatively. Histologically, necrosis, hemorrhage and endothelial hyperplasia were revealed at the tumor lesion. The tumor was composed of proliferation of glial and mesenchymal elements. The glial element appeared as fibrillary astrocytoma and polar spongioblastoma. The mesenchymal element showed sarcoma. As mentioned above, this tumor was diagnosed as gliosarcoma. It was difficult to make a diagnosis of gliosarcoma preoperatively because of the complex findings similar to malignant gliomas in conventional neuroradiological imaging.(ABSTRACT TRUNCATED AT 250 WORDS)

Rhythmic oscillations of blood pressure and R-R interval in patients with chronic renal failure

Rhythmic blood pressure (BP) and R-R interval (R-R) oscillations at low-, mid- and high-frequency bands (LF: 0.02-0.06 Hz; MF: 0.07-0.14 Hz; HF: 0.15-0.40 Hz) were compared between uraemic patients maintained on haemodialysis and control subjects. The LF and MF power spectra of BP were attenuated more in patients than in controls. With subjects standing, the MF power spectrum of BP increased significantly in both groups. With subjects supine, the plasma norepinephrine concentration was higher, and its increment upon standing was greater in patients than in controls. Each R-R frequency power spectrum decreased more in patients than in control subjects. The HF power spectrum of R-R, i.e. a vagal tone index, systematically decreased upon standing in the control subjects but not in the patients. The linear coupling between BP and R-R oscillations was strongest in the HF band, decreasing in the MF and LF bands. Transfer function analysis indicated that, in uraemic patients, linear BP/R-R relationships were altered in the HF band but remained normal in the LF and MF bands. The present results suggest that, first, the decreased amplitude of Mayer waves, i.e. the MF power spectrum of BP, observed in uraemic patients can be attributed to low sensitivity of the vasculature to sympathetic stimuli, and, secondly, autonomic modulation of linear BP/R-R relationships is frequency-dependent.

Desmoplastic infantile ganglioglioma with extraparenchymatous cyst--case report

A large supratentorial tumor associated with an extraparenchymatous cyst and multiloculated intraparenchymatous cysts occurred in a 14-month-old infant. This case had all the characteristic features of desmoplastic infantile ganglioglioma both clinically and histologically. The notable difference was the extraparenchymatous cyst. The extraparenchymatous cyst was probably caused by entrapment of cerebrospinal fluid in the subarachnoid space by some check-valve mechanism because the leptomeninges were commonly involved in the tumor. A similar mechanism may explain the etiology of the intraparenchymatous, disproportionately large cyst in desmoplastic infantile gangliogliomas.

[The effects of intrarenal infusion of recombinant human erythropoietin on renal hemodynamics and renal function in anesthesized rabbits]

To determine whether recombinant human erythropoietin (rHuEPO) has direct effect on mean arterial pressure or renal function, rHuEPO was infused intrarenally at a rate of 100 U min-1 for 30 min in anesthetized rabbits without renal failure. Intrarenal infusion of rHuEPO resulted in no change in mean arterial pressure, renal blood flow, or renal vascular resistance as compared with vehicle control. rHuEPO also produced no significant change in glomerular filtration rate, filtration fraction, or arterial hematocrit. However, urine volume, urinary excretion of sodium and potassium, and fractional sodium excretion were significantly reduced by intrarenal infusion of rHuEPO. These observations demonstrate that rHuEPO has no direct effects on mean arterial pressure or renal hemodynamics, whereas rHuEPO stimulates net tubular sodium reabsorption possibly by direct tubular action, and reduces urine volume and urinary excretion of sodium and potassium in anesthetized rabbits without renal failure.

Plasma concentrations of immunoreactive-endothelin in patients with chronic renal failure treated with recombinant human erythropoietin

1. Elevation of blood pressure is one of the major side effects of recombinant human erythropoietin therapy in haemodialysis patients. 2. We investigated the possible involvement of endothelin in the pathogenesis of this recombinant human erythropoietin-induced blood pressure elevation in 51 patients undergoing maintenance haemodialysis. 3. Blood haemoglobin level increased from 7.1 +/- 0.1 to 8.8 +/- 0.1 g/dl (means +/- SEM) after 8 weeks of treatment with recombinant human erythropoietin (3000-4500 units/week). An increase in mean blood pressure was found in 19 patients (37%) (n = 9, by 0-10 mmHg; n = 10, by > 10 mmHg). 4. Plasma immunoreactive-endothelin concentration significantly increased from 2.26 +/- 0.18 to 3.14 +/- 0.31 pmol/l in the 10 patients whose mean blood pressure increased by more than 10 mmHg (P < 0.05), but not in the other patients. Moreover, the increase in plasma immunoreactive-endothelin concentration showed a significant positive correlation with the change in mean blood pressure in 19 patients with elevated mean blood pressure (r = 0.47, P < 0.05). 5. There was no significant correlation between the change in plasma immunoreactive-endothelin concentration and the change in blood haemoglobin level or the change in body weight. 6. These results suggest the possibility that endothelin may contribute to the recombinant human erythropoietin-related rise in blood pressure in some haemodialysis patients.

Effect of slow release nifedipine tablets in patients with essential hypertension

The antihypertensive effect of slow release nifedipine (CAS 21829-25-4) tablets (20 mg, Adalat) administered once or twice daily was studied in patients with essential hypertension of WHO stage I or II. Ambulatory blood pressure was monitored by a finger volume oscillometric device every 5 min for 24 h before and during the treatment with nifedipine. Whether administered once or twice daily, nifedipine tablets dit not change the pattern of circadian blood pressure variation; i.e. diurnal rise and nocturnal fall. Twice daily administration induced a significant downward shift in the blood pressure pattern. In other words, further hypotensive effect was observed during the night when the blood pressure was already low. On the other hand, administration once daily in the morning lowered daytime blood pressure without affecting blood pressure during the night. The duration of action of nifedipine tablets administered once daily was 12 h or more. In the acute experiment using 20 mg tablets of nifedipine, plasma concentration of nifedipine was well correlated with the percentage change in mean blood pressure. The minimal effective plasma concentration of nifedipine was estimated to be 13.4 ng/ml. However, in chronic treatment, nifedipine lowered blood pressure at the plasma concentration of 10 ng/ml. The results indicate that nifedipine tablets administered once daily provide an effective antihypertensive regimen for controlling daytime hypertension with minimal antihypertensive effect during the night.