Neurological manifestations in Japanese Ama divers.

Repetitive breath-hold (BH) diving can lead to accumulation of nitrogen (N2) in blood and tissues, which may give rise to decompression illness (DCI). An unusual condition is "Taravana", the diving syndrome reported by Cross in the 1960s. That report generated wide discussion as to whether BH diving can cause DCI. Paulev was the first person to suggest the link between DCI and BH diving. He, a submarine medical officer developed symptoms of DCI after a series of BH dives, having proceeded the dives by spending time in a hyperbaric chamber at 20 meters for 8 minutes. Recently four professional Japanese BH divers (Ama) with histories of diving accidents were reported. Magnetic resonance imaging of these divers detected cerebral infarcts localized in the watershed areas of the brain. A survey conducted on their island revealed that many Ama divers had experienced stroke-like events. A clinical feature of DCI in BH diving is that the damage is limited to the brain. Although the mechanisms of brain damage in BH diving are unclear, N2 bubbles passing through the lungs or the heart so as to become arterialized are most likely to be the etiological factor.

Auditory evoked potential index predicts the depth of sedation and movement in response to skin incision during sevoflurane anesthesia.

BACKGROUND: The auditory evoked potential (AEP) index, which is a single numerical parameter derived from the AEP in real time and which describes the underlying morphology of the AEP, has been studied as a monitor of anesthetic depth. The current study was designed to evaluate the accuracy of AEPindex for predicting depth of sedation and anesthesia during sevoflurane anesthesia. METHODS: In the first phase of the study, a single end-tidal sevoflurane concentration ranging from 0.5 to 0.9% was assigned randomly and administered to each of 50 patients. The AEPindex and the Bispectral Index (BIS) were obtained simultaneously. Sedation was assessed using the responsiveness portion of the observer's assessment of alertness-sedation scale. In the second phase of the study, 10 additional patients were included, and the 60 patients who were scheduled to have skin incisions were observed for movement in response to skin incision at the end-tidal sevoflurane concentrations between 1.6 and 2.6%. The relation among AEPindex, BIS, sevoflurane concentration, sedation score, and movement or absence of movement after skin incision was determined. Prediction probability values for AEPindex, BIS, and sevoflurane concentration to predict depth of sedation and anesthesia were also calculated. RESULTS: The AEPindex, BIS, and sevoflurane concentration correlated closely with the sedation score. The prediction probability values for AEPindex, BIS, and sevoflurane concentration for sedation score were 0.820, 0.805, and 0.870, respectively, indicating a high predictive performance for depth of sedation. AEPindex and sevoflurane concentration successfully predicted movement after skin (prediction probability = 0.910 and 0.857, respectively), whereas BIS could not (prediction probability = 0.537). CONCLUSIONS: Auditory evoked potential index can be a guide to the depth of sedation and movement in response to skin incision during sevoflurane anesthesia.

Radiotherapy after hyperbaric oxygenation improves radioresponse in experimental tumor models.

We examined the effect of radiotherapy after hyperbaric oxygen (HBO) breathing in experimental tumors using a tumor growth delay assay. Tumor models used were SCCVII (radiobiological hypoxic fraction: approximately 10%) and 9L tumors (containing less hypoxic cells) subcutaneously transplanted into C3H/He mice and Fisher 344 rats, respectively. Irradiation using X-rays was locally administered to the tumors immediately after decompression. HBO breathing enhanced the radiation response in SCCVII tumors but not in 9L ones. In the next experiment using SCCVII tumors, irradiation was administered 5, 15, 30, and 90 min after decompression. A significant growth delay was seen in the treated animals within 30 min after HBO breathing, and the tumor growth delay time was prolonged 1.61 times as long as that in radiotherapy alone. We concluded that: (1) radiotherapy after HBO breathing is effective for tumors with hypoxic cells; and (2) the time lapse from decompression to irradiation is an important factor in improving radiosensitivity. Radiotherapy after HBO breathing can be used to enhance the efficacy of clinical treatments.

Does nitrous oxide antagonize sevoflurane-induced hypnosis?

We have studied 64 ASA I and II patients (aged 20-60 yr) to determine if nitrous oxide affects sevoflurane requirement for achieving 50% probability of no movement in response to verbal commands (MACawake). Patients were allocated randomly to one of four nitrous oxide concentration groups (0, 20, 40 and 60 vol.%). Patients in each group received sevoflurane at two different end-tidal concentrations according to a predetermined randomization table. After steady state sevoflurane and nitrous oxide concentrations had been maintained for at least 15 min, patients were assessed as being awake or asleep. The MACawake for sevoflurane was 0.63% and this was reduced significantly in a non-linear manner by increasing nitrous oxide concentration. A 50% reduction in MACawake was produced by a nitrous oxide concentration of 45%. The reduction in MACawake by nitrous oxide was non-linear; the interaction coefficient between nitrous oxide and sevoflurane being significantly less than zero (P = 0.0238), indicating that the reduction in MACawake by nitrous oxide was smaller than would be expected from simple additivity and that nitrous oxide antagonized the effects of sevoflurane in preventing response to verbal commands.

The effect of clonidine on sevoflurane requirements for anaesthesia and hypnosis.

We evaluated the effects of clonidine given orally on sevoflurane requirements for anaesthesia and hypnosis. Patients received either clonidine (5 micrograms.kg-1) by mouth (n = 21) 90 min before surgery or no premedication (n = 21) by random allocation. MAC was calculated using repeated tetanic nerve stimulation with end-tidal sevoflurane concentration increased or decreased by 0.3 vol.% depending on the previous response. MAC awake was calculated according to the response to verbal command. The mean (SD) MAC in the clonidine-treated patients was 1.53 (0.20)% compared with 1.83 (0.15)% in the control group (p < 0.001). Similarly, MAC awake was reduced in the clonidine group (0.50 (0.08)% compared with 0.60 (0.07)% in the control group) (p < 0.001). We conclude that clonidine 5 micrograms.kg-1 orally administered pre-operatively reduces sevoflurane requirements for anaesthesia and hypnosis.

[Relationships between atmospheric Sugi (Japanese cedar)-pollen counts and indices of climatic conditions].

Atmospheric pollen surveys have been conducted using Durham's standard sampler for 12 years in Toyama Prefecture. The relationships between Sugi (Japanese cedar, Cryptomeria japonica D. Don) pollen and some indices of climatic conditions were analyzed. The results were as follows: 1. Total pollen counts showed a tendency to increase for 12 years, although the variation of the count was relatively large. 2. Significant correlations were found between pollen counts and some indices of the climatic conditions in July of the previous year, such as duration of sunshine, mean daily temperature and daily maximum, as well as minimum temperature. 3. Significant correlation was found between pollen count and duration of sunshine in January and March, and the amount of snowfall in March of the observed year using multiple regression analysis. Pollen counts were shown to be relatively high in years with short sunshine in January and long sunshine and heavy snow in March.

Dietary supplementation with L-arginine ameliorates glomerular hypertension in rats with subtotal nephrectomy.

This study was designed to examine the potential effect(s) of dietary supplementation with L-arginine on the renal microcirculation of female Munich-Wistar rats with ablation of 60 to 70% of total renal mass. All rats were fed a standard rat chow containing 22.8% protein (1.42% L-arginine). Groups 1 (N = 6) and 3 (N = 7) drank tap water and had micropuncture studies after 5 to 6 or 15 to 16 wk, respectively, of subtotal renal ablation. Groups 2 (N = 5) and 4 (N = 7) drank tap water supplemented with L-arginine (1%) and had micropuncture studies after 5 to 6 or 15 to 16 wk, respectively, of subtotal renal ablation. Glomerular micropuncture studies revealed no differences in any of the parameters of glomerular hemodynamics measured 5 to 6 wk after renal ablation (Groups 1 versus 2). However, by 15 to 16 wk postnephrectomy, values of glomerular capillary pressure and efferent arteriolar resistance were significantly greater and the glomerular capillary ultrafiltration coefficient was significantly lower in rats drinking tap water than in rats drinking tap water supplemented with L-arginine. Single-nephron GFR, single-nephron plasma flow rate, and afferent arteriolar resistance were not different between these two groups. The data suggest that the long-term administration of L-arginine prevents the progression of glomerular sclerosis in rats with subtotal nephrectomy, at least in part, by ameliorating glomerular capillary hypertension.

[Abnormalities of calcium, phosphorous and vitamin D metabolism with proximal renal tubular dysfunction in subjects environmentally exposed to cadmium].

Calcium, phosphorus and vitamin D metabolism were examined in 21 male and 13 female subjects with renal tubular dysfunction in the cadmium-polluted Jinzu River basin in Toyama prefecture, Japan. Multiple proximal renal tubular dysfunction was detected in all subjects showing increased FE beta 2-m and FFua, generalized aminoaciduria and renal glucosuria. Reduced ability of tubular reabsorption of phosphate resulted in hypophosphatemia in 31% of the women. Despite decreased tubular reabsorption of calcium, the level of serum calcium remained normal in all subjects. Serum 1,25-dihydroxyvitamin-D [1,25(OH)2D], which is produced in the proximal tubules through 1 alpha-hydroxylation from 25-hydroxyvitamin-D [25OHD], was normal or increased to more than 60pg/ml. The serum level of 1,25(OH)2D was inversely related to creatinine clearance in both the men (p < 0.05) and women (p < 0.01). Serum iPTH was slightly increased to more than 0.9 mg/ml, whereas the levels of other hormones, including 25OHD, calcitonin, thyroxine (T4) and triiodothyronine (T3) were normal. The serum alkaline phosphatase activity and serum osteocalcin concentration were significantly increased compared to those of controls in both sexes. Bone loss detected by the measurement of bone density was prominent in female subjects. These results support the hypothesis that the serum phosphate concentration is more important than the serum concentration of 1,25(OH)2D for abnormalities of bone metabolism in cadmium-induced renal tubular dysfunction.

Electrical pelvic floor stimulation in the management of urinary incontinence due to neuropathic overactive bladder.

Electrical pelvic floor stimulation employing a portable functional electrical stimulation system with percutaneously indwelling electrodes was carried out to improve detrusor urinary incontinence. Cyclic stimulation using negative going pulse trains of 20 Hz was applied 3 to 6 times daily to the bilateral pudendal nerves distributing to the pelvic floor muscles for the purpose of strengthening these muscles, including the urethral sphincter, and simultaneously, suppressing detrusor overactivity and increasing cystometric capacity. Electrical training for 4-8 weeks resulted in an improvement of urinary incontinence in five of six patients. In two of six cases incontinence had subjectively disappeared. Urodynamic investigations demonstrated an increase in detrusor reflex threshold and less tendency for abortive detrusor contraction. No apparent complications were encountered during these periods. This procedure appears to be efficient for the management of patients with detrusor incontinence who respond poorly to conservative therapies.

Effect of combined dopamine and bunazosin on the ischemic heart after occlusion of the coronary artery.

In order to investigate whether dopamine combined with bunazosin improves cardiac function, the global and regional cardiac function and regional blood flow of 7 anesthetized dogs were analyzed before and after occlusion of the left anterior descending coronary artery (LAD), then after 10 micrograms/kg/min dopamine infusion following the LAD occlusion, and again after a bolus infusion of bunazosin 250 micrograms/kg. Dopamine with bunazosin reduced left atrial pressure from 4.9 +/- 0.9 to 3.1 +/- 0.5 mmHg (p less than 0.05) and improved cardiac output from 1.22 +/- 0.15 to 1.50 +/- 0.14 L/min (p less than 0.05), maximum positive left ventricular dp/dt from 1721 +/- 202 to 3600 +/- 663 mmHg/sec (p less than 0.05) and the time constant from 45.2 +/- 5.0 to 27.5 +/- 4.6 msec (p less than 0.01). Bunazosin added to the dopamine reduced the elevated left ventricular peak systolic pressure caused by dopamine from 130 +/- 7 to 113 +/- 8 mmHg (p less than 0.01). With regard to the regional wall motion, the impaired LAD-delta L (the segment systolic shortening) and LAD-Elmax (the slope of peak systolic pressure--endsystolic length relation) following the LAD occlusion improved from 0.5 +/- 2.5 per cent to 5.9 +/- 2.6 per cent (p less than 0.01) and from 50 +/- 9 to 82 +/- 14 mmHg/mm (p less than 0.01) after the infusion of dopamine with bunazosin. Dopamine greatly increased the Rate Pressure Product (RPP) from 12610 +/- 1120 after LAD occlusion to 16950 +/- 1420, whereas dopamine in combination with bunazosin did not increase the RPP due to a drop of LV-PSP with little change in regional myocardial blood flow. It was concluded that combining dopamine with bunazosin was useful for improving both the global and regional cardiac functions of the ischemic heart.

Clinical experience with alumina ceramic transcutaneous connector to prevent skin-exit infection around CAPD catheter.

To prevent skin-exit infection, an important CAPD complication, we developed a transcutaneous connector made of Alumina ceramic. The new connector could be downsized, because an Alumina ceramic is characteristically bio-inert, rigid and non-porous. Our animal experiments with Alumina ceramic in soft tissue demonstrated the outstanding bio-compatibility of this material. The shape of the new transcutaneous connector was of simple cylindrical configuration so as to inhibit macrostress beneath the skin. To make contact with this connector in the body, a silicon tube was made into a Swan-necked catheter with a disk-shaped polyester cuff, which was positioned subcutaneously beneath the transcutaneous connector in order to reinforce adhesion to soft tissue. The silicon tube itself was L-shaped in its outside portion just before reaching the connector. We are now using this new transcutaneous connector made of Alumina ceramic on a CAPD catheter in 8 patients. In the longest case of a patient using it, there has been no skin-exit infection for 12 months. Also, there has been virtually no downgrowth phenomenon in the skin around the connector, and the connector and tissue have remained in very close contact, although fibrous connective tissue has been seen to form in the area.

Effectiveness of chemoembolization therapy for metastatic right atrial tumor thrombus associated with hepatocellular carcinoma.

A rare case of hepatocellular carcinoma (HCC) was complicated by metastatic right atrial tumor thrombus (RATT), which diminished in size on echocardiograms and showed necrotic change on computed tomography (CT) scans after chemoembolization therapy.