Usefulness of leg-crossing for maintaining blood pressure in a sitting position in patients with orthostatic hypotension--case reports

The authors report a case with idiopathic orthostatic hypotension in which the patient prevents his blood pressure from falling to a symptomatic level by leg-crossing in a sitting position. Including 4 other patients with orthostatic hypotension and 5 normal subjects, their study found that the changes in blood pressure with leg-crossing inversely correlated with those induced by assuming seated posture from a supine position. Leg-crossing may, therefore, be one of the useful nonpharmacologic measures for maintaining blood pressure in a sitting position in patients with orthostatic hypotension.     

Severe hypertension with segmental renal infarction following surgical removal of a retroperitoneal malignant hemangiopericytoma: a case report

Severe hypertension developed in a fifty-five year-old woman after surgical removal of a retroperitoneal tumor, when the renal artery was injured. Renal arteriography after the surgery demonstrated a segmental infarction of the right kidney. A close relationship between activation of the renin-angiotensin system and the development of severe hypertension was observed. Satisfactory control of blood pressure concomitant with reduction of plasma renin activity was achieved by a combination of an angiotensin-converting anzyme inhibitor, beta-blocking agent, and calcium-entry blocker. The mechanism of activation of the renin-angiotensin system in renal infarction is discussed.     

Effects of air-jet stress on renal blood flow in spontaneously hypertensive rats

Background Stressful psychological stimuli produce an increase in renal sympathetic nerve activity (RSNA) and a decrease in renal blood flow. Very few direct analyses of the relationship between RSNA and renal blood flow during the application of psychological stimuli have been conducted by recording these 2 measurements simultaneously in the same individual animals. Methods We simultaneously measured RSNA and renal blood flow as a Doppler shift in conscious, unrestrained, spontaneously hypertensive rats. The rats were stressed by directing a continuous air jet at their faces for 20 seconds. Results Air-jet stimulus increased RSNA 81%±15% (mean±standard error of the mean, n=10), mean arterial pressure (21±3 mm Hg), and renal vascular resistance (37%±6%), and decreased renal blood flow (−15%±2%). The percentage change in RSNA correlated positively with the change in mean arterial pressure (r=0.934,P<0.001) and percentage change in renal vascular resistance (r=0.912), and negatively with the percentage change in renal blood flow (r=−0.804). The denervation of renal nerves prevented renal blood flow from decreasing in response to air-jet stress. Conclusions A reduction in renal blood flow in response to short-term air-jet stress is elicited mainly by neural mechanisms in spontaneously hypertensive rats. Enhancement of RSNA by air-jet stimulus exerts a potent constricting effect on the renal vascular bed, resulting in a reduction in renal blood flow.     

Preemptive analgesia by zaltoprofen that inhibits bradykinin action and cyclooxygenase in a post-operative pain model

The post-operative pain state results from a barrage of primary afferent inputs exposed to products of tissue damage such as bradykinin and prostaglandins and the central sensitization by the continuing inputs. This provides the rationale for preemptive analgesia, whereby the blockade of primary afferent inputs prior to injury may result in a reduction of post-operative pain. 2-(10,11-dihydro-10-oxo-dibenzo[b,f]thiepin-2-yl) propionic acid (zaltoprofen) is a unique compound that inhibits cyclooxygenase (COX) and exhibits anti-bradykinin activity. The present study evaluated the preemptive analgesic effect of zaltoprofen in a post-operative pain model produced by plantar incision. When orally, but no intrathecally, administered 30 min prior to incision, zaltoprofen significantly increased the withdrawal threshold 2 h and 1-3 days after incision at 10 mg/kg. While the bradykinin B1 antagonist des-Arg10-HOE-140, the selective COX-1 inhibitor SC-560, and the selective COX-2 inhibitor celecoxib did not affect post-operative pain, the B2 antagonist HOE-140 dose-dependently relieved the post-operative pain at 2-200 microg/kg with a time course similar to that of zaltoprofen. The B2 receptor mRNA was expressed in the hindpaw and the expression did not change before and 24 h after surgery. These results suggest that zaltoprofen produces the preemptive analgesic effect peripherally by blocking the B2 pathway.     

Carbamazepine induced hyponatremia

Carbamazepine (CBZ) is a drug which can induce the syndrome of inappropriate antidiuretic hormone (SIADH). Until 1980's, there were reports regarding CBZ-induced SIADH, but it is rarely reported these days. We here report two cases of CBZ-induced SIADH. Hyponatremia in these cases was rapidly improved by withdrawal of administration of CBZ. According to the previous reports, the rate of hyponatremia in patients receiving CBZ is not small. It ranges from 48% to 31%. As CBZ is frequently used for patients with epilepsy and neuralgia, not only their blood CBZ concentration but also their serum Na level should be monitored.     

Effect of single-administration captopril on plasma and urinary vasopressin in normotensive subjects and patients with essential hypertension and primary aldosteronism

Effects of a single administration of captopril on plasma and urinary vasopressin (AVP) were examined in 8 normotensive (NT) female volunteers, 17 patients with essential hypertension (EHT) and 2 patients with primary aldosteronism (PA). Orally-administered captopril (25 mg) had no effect on plasma AVP levels in the three groups. However, urinary excretion of AVP decreased significantly after use of captopril in both NT and EHT subjects (-57% and -67%, respectively), and also in PA subjects. The magnitude of reduction in urinary AVP was significantly correlated with the pretreatment levels of plasma renin activity (r = 0.85) and plasma aldosterone concentration (r = 0.88) in NT subjects. Such correlation was not found in EHT subjects. These results suggest that captopril decreases AVP secretion in both normotensive and hypertensive subjects, but the relation of the magnitude in AVP reduction by captopril to the peripheral renin-angiotensin system might be different.     

Association of vitamin D receptor gene polymorphism with renal cell carcinoma in Japanese

Molecular epidemiologic studies have reported a relationship between 1alpha,25 dihydroxyvitamin D3 (1,25(OH)2D3) and the development and progression of malignant tumors. (1,25(OH)2D3) exerts its biological activity by binding the vitamin D receptor (VDR), while recent studies have demonstrated that VDR gene polymorphisms affect serum levels of (1,25(OH)2D3). Serum levels of (1,25(OH)2D3) are reported to be significantly lower in patients with renal cell carcinoma (RCC) compared to non-cancer control patients. The purpose of this study was to investigate the TaqI VDR polymorphism in Japanese RCC patients and non-cancer controls in order to determine if an association exists between VDR genotype and the risk of developing RCC as well as clinical risk factors. A total of 102 RCC patients and 204 controls were genotyped for a previously described TaqI restriction fragment length polymorphism (RFLP) of the VDR gene. Products were digested into T allele or the t allele according to the absence or presence of a TaqI restriction site. Individuals were classified as TT, Tt or tt. The genotype TT was statistically more frequent among RCC patients (80.4%) compared to controls (61.8%) (OR = 2.54; 95% CI, 1.44-4.46; p = 0.0006). In addition, the occurrence of the genotype TT was significantly higher in patients with rapid-growth-type group (92.1%) compared to slow-growth-type group (73.4%) (OR = 4.22; 95% CI, 1.15-15.53; p = 0.0175). These data demonstrate that VDR genotype plays an important role in determining the risk of developing more aggressive RCC in Japanese.     

Antibiotic susceptibility of glutaraldehyde-tolerant Mycobacterium chelonae from bronchoscope washing machines

BACKGROUND: Contamination of bronchoalveolar lavage fluid is a major problem in the world. Although 2% glutaraldehyde (GA) is widely used as a disinfectant for bronchoscope cleaning, recently, GA-tolerant mycobacteria have been isolated, which makes this problem more complicated. METHODS: We studied the susceptibility to GA and antibiotics of mycobacteria isolated from bronchoscope washing machines in our hospital. We also studied the minimum inhibitory concentrations of GA and antibiotics with pump inhibitors. RESULTS: Twenty-nine mycobacteria were isolated, of which 26 were Mycobacterium chelonae. Among 18 isolates of M chelonae, excluding 8 isolates in which some results were not reproducible, 50% (9 of 18) were 2% GA-tolerant. One hundred percent (9 of 9) of the GA-tolerant isolates and 11% (1 of 9) of the GA-sensitive isolates were either resistant or intermediately resistant to 2 or 3 classes of antibiotics. Efflux pump inhibitors did not influence the susceptibility to GA and antibiotics. CONCLUSIONS: It was suggested that there might be an association of GA tolerance with antibiotic resistance in M chelonae. There may a different mechanism(s) other than that involving efflux pumps with regard to GA tolerance and antibiotic resistance in M chelonae. When bronchoscopy-related mycobacterial infections are suspected, physicians and clinical microbiologists should exercise care in handling GA-tolerant mycobacteria, which may be resistant to multiple antibiotics.