The gas trophicity of pathogenic bacteria]

Yersinia pseudotuberculosis and Listeria have been shown to be capable of assimilating carbon dioxide from the air and using its carbon for the synthesis of biopolymers of the bacterial cell. These microorganisms, the causative agents of saprozoonotic infections, have also been found to be capable of assimilating molecular nitrogen from the air in small amounts. The data on the influence of the growth conditions of the cultures (hydrogen concentration, the presence of carbon dioxide and oxygen, temperature) on the activity of acetylene reduction by microbial cells. At low temperature molecular nitrogen is fixed by Listeria twice as actively as by Y.pseudotuberculosis. Not all bacterial strains under study have been found to be capable of acetylene reduction. The presence of fixed nitrogen in the medium suppresses the process of the reduction of acetylene into ethylene.     

Expression of LECAM-1 and LFA-1 on pre-B lymphoma cells but not on preneoplastic pre-B cells in SL/KH mice

BACKGROUND AND OBJECTIVES: The efficacy of operatively administered spinal neostigmine to provide analgesia and that of different antiemetics to prevent neostigmine-related nausea and vomiting were evaluated in patients undergoing tibial or ankle reconstruction. METHODS: One hundred patients were randomized to five groups (n = 20). The intravenous antiemetic test drug (except propofol) was given as premedication in the holding room, after intravenous midazolam, 0.05 mg/kg. The subarachnoid drugs administered were 20 mg bupivacaine (0.5%) in conjunction with 100 micrograms neostigmine, except for the saline group (S group), which received bupivacaine and saline. The S group, the neostigmine group (N group), and the propofol group (P group) received saline as the intravenous test drug. The droperidol group (D group) received intravenous droperidol 0.5 mg, and the metoclopramide group (M group) received intravenous metoclopramide 10 mg. The P group had a continuous intravenous propofol infusion (2-4 mg/kg/hr), started 10 minutes after the spinal injection. Nausea, emetic episodes, and the need for analgesic (disclofenac) or antiemetic medication were recorded for the first 24 hours following surgery and scored by a 10-cm visual analog scale (VAS). RESULTS: Subarachnoid neostigmine 100 micrograms did not affect subarachnoid bupivacaine analgesia as measured by time to first rescue analgesic in most patients, but it decreased the overall 24-hour visual analog scale (VAS) scores and the need for postoperative analgesics in 24 hours (P < .001). The incidence of intraoperative nausea and vomiting was higher in the N, D, and M groups than in the S group (P < .001). Following surgery, the 3-hour VAS assessment for emesis was higher for the N, P, and M groups than for the S group (P < .05). The overall 24-hour assessment was similar among groups. CONCLUSIONS: Subarachnoid neostigmine reduced postoperative pain scores and analgesic requirements. Whether it prolonged the duration of action of diclofenac or enhanced the mechanisms involved in spinal analgesia cannot be determined from these data. Although propofol and droperidol appeared to be more effective during and after surgery, respectively, all neostigmine groups were associated with a high consumption of antiemetics.     

Effect of various marine lipids on transdermal drug delivery--in vitro evaluation

The effects of several marine lipids on the penetration of hydrocortisone and nitroglycerin through excised hairless mouse skin have been studied. Fatty acid extracts obtained by hydrolysis of Portuguese dog-fish-liver-oil or by hydrolysis of cod-liver-oil were shown to be effective skin penetration enhancers. Phospholipid obtained from squid was also shown to be effective enhancer. However, the enhancing effect of the marine products could generally be associated with their content of free unsaturated fatty acids. The fatty acid extract obtained from cod-liver-oil caused insignificant skin irritation when incorporated into an ointment base and applied to human skin.     

Collapsed ultraendurance athlete: proposed mechanisms and an approach to management

OBJECTIVE: To review the common conditions causing collapse in ultraendurance athletes, to propose appropriate treatment protocols for the more common medical conditions that are encountered, and to provide practical guidelines for the management of the medical facilities at these endurance events. DATA SOURCES: Books published on the subject, abstracts of the American College of Sports Medicine Annual Congress dealing with the subject over the last 5 years, and electronic search of the Medline and Current Contents databases (last searched May 1995). German articles were included in the search criteria. STUDY SELECTION: Articles dealing generally with the management of medical facilities at endurance events were chosen. Articles dealing more specifically with the common medical conditions encountered at these events were then sourced and included in this review. DATA EXTRACTION: Multiple reader extraction of relevant data. DATA SYNTHESIS: A practical guideline to the management of the medical facility at an endurance event is detailed, expanding specifically on the nature of the conditions causing collapse during or after endurance exercise with a proposed classification of causes of collapse for optimizing immediate management and management protocols for specific conditions such as heatstroke, hyponatremia, hypoglycemia, exercise-associated collapse, and muscle cramps. CONCLUSION: The most commonly encountered medical condition at endurance athletic events is collapse after the event. The popular view that all persons who collapse have dehydration-induced hyperthermia has been challenged. Here we extend that argument and provide diagnostic and management protocols and propose a triage system that considers the most common causes of collapse in ultraendurance athletes. These protocols can optimize the efficient and safe management of large numbers of collapsed ultraendurance athletes. It is proposed that these protocols can optimize the efficient and safe management of large numbers of collapsed ultra endurance athletes.     

Levels of PCDDs and PCDFs in farm cow's milk located near potential contaminant sources in Asturias (Spain). Comparison with levels found in control, rural farms and commercial pasteurized cow's milks

Cows milk samples from 12 dairy farms in Spain and 23 samples of pasteurised cows milk were analysed for PCDD/F. Farms located in rural areas without specific dioxin sources (background levels) ranged from 1.3 to 2.47 pg TEQ/g fat basis. These values were slightly lower than those found in milk from the vicinity of potential dioxin emission sources (waste incinerator, chemical and metallurgical industry) and similar to milk near paper industry. The waste incinerator seems to be the emission source with the highest influence on the cows milk gathered in its vicinity. Thus, milk near the waste incinerator exhibited the highest PCDD/F levels, the highest PCDF/PCDD ratio and its congener PCDD pattern showed the highest difference respect to its control point. The PCDD/F average concentrations found in pasteurised commercial milk were lower than those found in raw milk and were comparable to those found in retail milk from other countries.     

Apolipoprotein e4 allele and cognitive decline in elderly men

OBJECTIVES: To determine whether polymorphism of apolipoprotein E--notably, the e4 allele--predicts cognitive deterioration in the general population. DESIGN: Population based cohort investigated in 1990 and in 1993. SETTING: Zutphen, the Netherlands. SUBJECTS: Representative cohort of 538 Dutch men aged 70-89 at baseline. MAIN OUTCOME MEASURES: Cognitive function assessed by mini mental state examination, change in cognitive function and incidence of impaired cognitive function at three years. RESULTS: The baseline prevalence of impaired cognitive function (mini mental state examination score < or = 25) was higher among carriers of the e4 allele compared with men without the allele (41.0% (55) v 31.1% (122) P = 0.03), and this result was still valid after adjustment for age, occupation, smoking, alcohol use, and cardiovascular diseases. The decline in cognitive function at three years was largest in men homozygous for e4 (-2.4 points), intermediate in those heterozygous for e4 (-0.7 points), and lowest in men without e4 (-0.1 points), and it was independent of other risk factors (P = 0.02). The risk of developing impaired cognitive function during follow up was significantly increased in allele carriers compared with non-carriers (27.6% (16/58) v 15.5% (32/207)). The adjusted odds ratio was 2.87 (95% confidence interval 1.29 to 6.42). Twenty two per cent of the risk of developing impaired cognitive function in this population may be attributable to the e4 allele. CONCLUSIONS: The apolipoprotein e4 allele predisposes to cognitive decline in a general population of elderly men.     

Prothoracicotropic hormone in Manduca sexta: localization by a larval assay

1. A new method for the assay of insect prothoracicotropic hormone (PTTH) is described, using fourth instar larvae of Manduca sexta. Larvae neck-ligated at a critical time to prevent release of PTTH from the head fail to undergo the next larval moult. Such ligated larvae moult to fifth instar larvae or larval-pupal intermediates after injection of brain homogenates from Manduca larvae, pupae or pharate adults. The degree of response is proportional to the concentration of brain homogenate injected. 2. The source of PTTH in the pupal brain is the dorsal region of the protocerebrum containing the lateral neurosecretory cells. Microhomogennates of single pieces of brain showed activity with this method. 3. PTTH activity in partially purified extracts is water soluable, stable to boiling for 10 min, and is destroyed by Pronase or trypsin.     

Studies of prosody perception by cochlear implant patients

Prosodic information is conveyed to normally-hearing listeners by variations in acoustic fundamental frequency, amplitude envelope, and duration of speech segments. This study measured cochlear implant patients' sensitivity to these parameters in electrically coded speech. The psychophysical discrimination of electric parameters used to code prosodic information, were examined, together with prosody perception using speech processing strategies which modified the contributions of these parameters. Patients were implanted with the Cochlear Limited prosthesis and used the MPEAK speech processing strategy. In the psychophysical studies, difference limens were measured for steady-state and time-varying stimuli, of different pulse rates and pulse durations, over a series of different stimulus durations. These limens were obtained using an adaptive procedure which converged on the 50 per cent correct point. In the prosody perception studies, performance was measured for the MPEAK strategy and for strategies which modified the contributions of pulse rate and pulse duration. Data were collected for five tests of prosodic contrasts. Difference limens for steady-state pulse rates were larger at higher rates (17 per cent at 400 pulses/s) than at lower rates (6 per cent at 100 pulses/s). For some patients, limens for the time-varying pulse rates were larger than those for the steady-state pulse rates while for the other patients, the limens were similar. Difference limens for pulse duration were 0.3 dB, corresponding to 4 per cent of the dynamic range, for steady-state stimuli and doubled in size for the time-varying stimuli. Prosody perception performance was generally poorer for the modified strategies than for the MPEAK strategy, suggesting that the removal of information coded by pulse rate and pulse duration reduced the perception of prosodic contrasts.