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.

Evaluation of HBO2 therapy in pneumatosis cystoides intestinalis.

Pneumatosis cystoides intestinalis (PCI) is a disease characterized by retention of gas in the intestinal wall. Retention of gas can be caused by three mechanisms; gas entry through the intestinal mucosa, gas dissection from the pulmonary alveoli and bronchi, and gas generation in the mucous membrane. Since gas in cysts is composed almost entirely of nitrogen, hyperbaric oxygen therapy (HBO2) is effective for treating PCI due to the oxygen windows effect. However, PCI, caused by a mechanism involving pulmonary alveoli or branches, can become aggravated by HBO2. Therefore, we propose modifying HBO2 protocols for cases that do not require an invasive treatment. This study describes favorable results obtained in 2 PCI cases after HBO2 therapy according to our protocol.

Effectiveness of a stress management program for family caregivers of the elderly at home.

The aim of this study is to investigate the efficacy of a structured intervention program in emotional and physical states of family caregivers for elderly. This program is a series of five weekly 90-minute sessions including psycho-education, problem-solving techniques, and relaxation training. Subjects were 56 primary caregivers looking after relatives with dementia or disability at home. Psychological inventories, i.e., Profile of Mood States (POMS) and General Health Questionnaire30 (GHQ-30) were administered at the period of 4 weeks before, pre-, post-intervention, and 2 months after intervention. They were taken a blood sample to measure natural killer (NK) cell activity at the 4 weeks before, pre-, and post-intervention. In the waiting list control group, there was no change in the POMS, the GHQ-30 and NK cell activity. The scores for depression, anger-hostility, tension-anxiety, confusion (POMS), and general illness, social dysfunction, anxiety and dysphoria, suicidal depression (GHQ-30) at the post-intervention decreased significantly when compared with pre-intervention scores. Moreover, there was persistence of the improvement during two months after intervention. Post-intervention NK cell activity was significantly higher than the pre-intervention. These results indicated that our program was effective in managing the stress of family caregivers.

Physical effects of negative air ions in a wet sauna.

The physical effects of negative air ions on humans were determined in an experimental sauna room equipped with an ionizer. Thirteen healthy persons took a wet sauna bath (dry bulb temperature 42 degrees C, relative humidity 100%, 10 min exposure) with or without negative air ions. The subjects were not told when they were being exposed to negative air ions. There were no differences in the moods of these persons or changes in their blood pressures between the two saunas. The surface temperatures of the foreheads, hands, and legs in the sauna with negative ions were significantly higher than those in the sauna without ions. The pulse rates and sweat produced in the sauna with ions were significantly higher than those in the sauna without ions. The results suggest that negative ions may amplify the effects on humans of the sauna.

Alterations of fibrinolytic activity in human during and after hyperbaric oxygen exposure.

To clarify the stage of fibrinolytic activation by hyperbaric oxygen (HBO) exposure, we examined its alterations in human during and after the HBO exposure. Eight healthy female volunteers breathed oxygen at 284 kPa (2.8 atmospheres absolute). Blood samples were collected before compression, shortly after compression to the pressure 284 kPa, shortly before the start of decompression, shortly after decompression, and then again 3 hours after decompression. We estimated the euglobulin fibrinolytic activity (EFA) and, the activities and antigens of both tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1). The PAI-1 activity and PAI-1 antigen showed significant decrease after compression to a pressure 284 kPa, before the start of decompression, and after decompression. The EFA level and t-PA activity rose significantly shortly after decompression, and 3 hours later returned on baseline. These findings suggest that fibrinolytic activity is elicited after HBO rather than during HBO.

[Amyotrophic lateral sclerosis and mercury--preliminary report].

The mercury and selenium content in the hair of 13 ALS cases was studied by neutron activation analysis. The total mercury content of the hair was 3.70 +/- 2.73 ppm (mean +/- standard deviation) in the ALS patients as a whole, 4.46 +/- 3.16 ppm in the ALS patients from the middle of Kii Peninsula, and 2.49 +/- 1.38 ppm in the ALS patients from other region. As the comparison, mercury content was 2.43 +/- 0.79 ppm in the patients with Parkinsonism, and 2.10 +/- 1.13 ppm in the patients with multiple sclerosis (MS). The selenium content of the hair was 0.36 +/- 0.35 ppm for all ALS patients as a whole, 0.45 +/- 0.25 ppm in the ALS patients from the middle of the Kii Peninsula, and 0.21 +/- 0.47 ppm in the ALS from other region. There were no cases with higher values than mean values of control group, except one case from other regions. It is well known that the selenium decreases the toxicity of mercury in the human body. From these data mercury with low content of selenium might be one of the environmental factors which are thought to be involved in producing of ALS.