Continuous Measurement of O2 Consumption and CO2 Elimination During a Wakeful Hypometabolic State

Abstract

A previous investigation has demonstrated that the practice of a meditational technique elicits a wakeful, hypometabolic state. Measurement of O₂ consumption and CO₂ elimination was made by sampling techniques; mean values of these parameters were calculated from 6–10 minute samples. The present study extends this investigation, using a recently developed method of continuous measurement of O₂ consumption and CO₂ elimination. Continuous measurement of these parameters permitted the determination of mean values for the entire experimental periods as well as for selected intervals and permitted the examination of the sequence of respiratory changes. The present study reports statistically significant decreases in O₂ consumption of 5 percent and CO₂ elimination of 6 percent for the entire 20 minutes of the meditation period. These are lower than the sample values of 16 percent and 15 percent reported in the previous study. However, when selected intervals of the meditation period are examined, decreases in O₂ consumption and CO₂ elimination are comparable to those previously reported. The results are consistent with the difference between the discontinuous sampling measurement method originally employed and the continuous measurement method of the present investigation.     

TOXICOKINETICS OF INHALED BENZO[a]PYRENE: Plasma and Lung Bioavailability

Bioavailability and toxicokinetic studies are essential in order to establish dose-response relationships of widely distributed environmental toxicants such as benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon. Fischer 344 rats were exposed for 4 h (via nose-only inhalation) to aerosol exposure concentrations of 0.1, 1.0, and 2.5 mg/m³ of BaP absorbed onto carbon black particles using a state-of-the-art model aerosol generation system. Nominal and chamber concentrations of the particulate aerosol were determined gravimetrically with a seven-stage cascade impactor. The average aerosol for the 3 exposure concentrations used in this study exhibited a trimodal distribution with 93% cumulative mass less than 15.85 µm, 89% cumulative mass less than 10 µm, 55.3% cumulative mass less than 2.5 µm, and 38% less than 1 µm. Fifty-five percent of the aerosol had a cumulative mass less than PM_2.5     

The First Reported Case of Anti-Dob Causing an Acute Hemolytic Transfusion Reaction

The antibodies of the Dombrock blood group system have only rarely been encountered in transfusion practice, and anti-Do^b has not previously been implicated in an acute hemolytic transfusion reaction. We have encountered the first such case involving a chronically transfused black female with hemoglobin SS disease and multiple antibodies in her serum. During a previous admission for sickle cell crisis, the patient received 3 units of compatible blood with no untoward effects. Serum obtained 21 days later contained, in addition to the known antibodies, anti-S plus an unidentified antibody showing characteristics of HTLA. Blood lacking the E, K1, Fy(a), Jk(b) and S antigens was obtained, and 2 least incompatible units were transfused. While administering the second unit, the patient complained of fever and low back pain, and hemoglobinemia was detected. Anti-Do^b was identified in the post-reaction samples by absorption-elution tests, and the patient was confirmed to be Do(a+b–). The first unit transfused during this hemolytic episode tested Do (b+). This case, and a similar case involving anti-Do^a reported in 1986, strengthens the belief that Dombrock antibodies are clinically significant and illustrates the need for their differentiation, prior to transfusion from less clinically significant HTLA antibodies.     

Behavioral disturbances, not cognitive deterioration, are associated with altered food selection in seniors with Alzheimer's disease

OBJECTIVE: We previously reported alterations in circadian patterns of food intake that are associated with measures of functional and cognitive deterioration in seniors with probable Alzheimer's disease (AD). This study further explored disturbed eating patterns in AD, focusing on alterations in macronutrient (protein, carbohydrate, and fat) selection, and their association with measures of functional and behavioral losses. METHODS: Forty-nine days of food intake collections were conducted on 32 residents (26 females, 6 males; age = 88.4 +/- 4.1 years; body mass index = 24.1 +/- 4.0 kg/m(2)) with probable AD residing at a nursing home (a fully accredited geriatric teaching facility affiliated with the University of Toronto's Medical School). All residents ate their meals independently. The relationships between patterns of habitual food consumption and measures of cognitive function (Severe Impairment Battery), behavioral disturbances (Neuropsychiatric Inventory-Nursing Home Version) and behavioral function (London Psychogeriatric Rating Scale) were examined, cross-sectionally. RESULTS: Consistent with our previous studies, breakfast intakes were not predicted by any of the measures of behavioral, cognitive, or functional deterioration, although those residents with greater functional deterioration, especially disengagement, attained lower 24-hour energy intakes. The presence of "psychomotor disturbances," including irritability, agitation, and disinhibition, were strongly associated with shifts in eating patterns toward carbohydrate and away from protein, placing individuals with these conditions at increased risk for inadequate protein intakes. Between-individual differences in intake patterns could not be explained by the use of either anorexic or orexigenic medications. CONCLUSIONS: Behavioral, not cognitive, deterioration is associated with appetite modifications that increase risk of poor protein intake, perhaps indicating a common monoaminergic involvement.     

Efficacy of artesunate plus pyrimethamine-sulphadoxine for uncomplicated malaria in Gambian children: a double-blind, randomised, controlled trial

This double-blind, randomized, controlled study investigated the efficacy, safety and tolerability of artesunate plus pyrimethamine-sulphadoxine for uncomplicated malaria among Gambian children. Combined use of artesunate and pyrimethamine-sulphadoxine was hypothesized to delay or prevent resistance, which proved to be effective in reducing childhood mortality in sub-Saharan Africa. A total of 600 children with acute uncomplicated Plasmodium falciparum malaria, 6 months to 10 years old, were randomly administered pyrimethamine-sulphadoxine (25 mg/500 mg) with placebo, 4 mg/kg body weight pyrimethamine-sulphadoxine plus 1 dose of artesunate, or pyrimethamine-sulphadoxine plus 4 mg/kg body weight artesunate for 3 days. Results indicate that combined treatment was well tolerated. On day 1, 178 of 381 children treated with artesunate were still parasitemic compared with 157 of 195 children in the pyrimethamine-sulphadoxine group. On the other hand, failure rates on day 14 were 3.1% in the pyrimethamine-sulphadoxine group and 3.7% in the 1-dose artesunate group and 1.6% in the 3-dose group. Insignificant differences were found among children administered 1-dose and 3-dose artesunate, and were found less likely to be gametocytemic after treatment. In conclusion, this study confirms the safety and efficacy of a combined treatment, which eventually results in lower gametocyte rates and lower transmission rates.