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At least 847 records · Page 47Linked to original sources
PubMed2004

Alligators as West Nile virus amplifiers.

Recent evidence suggests that American alligators (Alligator mississippiensis) may be capable of transmitting West Nile virus (WNV) to other alligators. We experimentally exposed 24 juvenile alligators to WNV parenterally or orally. All became infected, and all but three sustained viremia titers >5.0 log10 PFU/mL (a threshold considered infectious for Culex quinquefasciatus mosquitoes) for 1 to 8 days. Noninoculated tankmates also became infected. The viremia profiles and multiple routes of infection suggest alligators may play an important role in WNV transmission in areas with high population densities of juvenile alligators.

Alligators and Crocodiles↗
PubMed1975

Effects of lowered environmental temperature on the growth of exoerythrocytic stages of Plasmodium berghei.

The effect of lowered host-environmental temperature upon the development and maturation of the preerythrocytic tissue stages of rodent malaria parasites has been investigated in two strains of Plasmodium berghei originating from the highlands of Katanga. Young albino rats inoculated with massive sporozoite doses of P. berghei NK 65 and maintained for 48 hours at 12 degrees C developed small, stunted tissue schizonts, averaging 11 X 15 microns, of a distinct morphology. Control rats kept at room temperature of 27 degrees C showed mature tissue schizonts of normal growth averaging 24 X 29 microns. Blood from the rats kept at lower temperature for 48 to 50 hours failed to produce parasitemia when inoculated into susceptible recipient mice. All the mice given blood from control rats developed parasitemia. However, when sporozite-inoculated rats were kept for 96 hours or longer at 12 degrees C they developed parasitemia and their liver showed maturation of 10% of the preerythrocytic schizonts. Experiments with the ANKA strain of P. berghei did not show significant differences in size and morphology between parasites in rats kept for 46.5 hours at 9 degrees C and 12 degrees C and those in controls kept at 20 degrees C. However, subinoculation of blood from the low temperature experimental groups into recipient mice at 46.5 hours after intravenous sporozoite inoculation failed to produce parasitemia, whereas all the recipient mice from the control groups developed parasitemia in 4 or 5 days. The findings are discussed in the light of the evolution of plasmodia and the phenomena of relapse and delayed primary attack in certain malaria infections.

Animals↗
PubMed1975

Problems related to postmenopausal women.

The most consistently troublesome symptom of the menopause is the hot flush. It can occur without warning or may be triggered off by emotion, exercise or change of environment or temperature. It is estimated that about 50% of women suffer from hot flushes, but only 5-10% of these seek medical advice. The cause is ascribed to excessive production of follicle-stimulating hormone. There is an increased sensitivity to the effect of locally released dilator substances in the peripheral vasculature.

Adult↗
PubMedDate not supplied

Freezing rate affects the survival of a short-term freezing stress in Panagrolaimus davidi, an Antarctic nematode that survives intracellular freezing.

The ability of the Antarctic nematode Panagrolaimus davidi to survive a short-term freezing stress depended upon the rate of freezing of its surroundings, measured as the duration of the sample exotherm. The freezing rate increased as the sample volume and freezing temperature decreased and resulted in fewer nematodes surviving. This appears to be due to the greater risk of physical damage by ice crystal growth at high freezing rates. Once frozen the nematodes will then survive exposure to lower temperatures. The environment of the nematode is likely to produce the slow rate of freezing of its surroundings that is necessary for its survival.

Animals↗
PubMed2002

Effect of ambient conditions on the antibacterial activity of antibacterial agent based on sodium titanium phosphate.

OBJECTIVE: To investigate the effects of ambient conditions on the antibacterial activity of inorganic antibacterial agent based on sodium titanium phosphate. METHODS: The number of live E. Coli ATCC 44113 was counted after the suspension was shaken and incubated in flask with antibacterial agent under ambient conditions. RESULT: The number of live bacteria increased when the concentration of bacteria increased in the range of 1.2 x 10(2) to 1.2 x 10(8) cfu/ml. The antibacterial activity increased with the increase of ambient temperature in the range of 16 approximately 46 degrees C, showing good antibacterial activity at human body temperature. With the increase of the concentrations of co-existing NaCl and protein, the antibacterial activity was found to decrease at first and level off at 0.01 g/ml and 0.0005 g/ml respectively. CONCLUSION: The antibacterial agent has to be used together with organic antibacterial agent in order to achieve good antibacterial effect when the ambient bacterial concentration is high. The antibacterial agent is promising to be used in the preparation of antibacterial cloth because it is highly effective at body temperature and expected to remain antibacterial in perspiration.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Effect of different storage methods on the viability of Halobacterium salinarum].

It has been established that the studied halobacteria are cryolabile and sensitive to the sharp change in osmotic pressure of the environment. Optimal temperature of their storage is +20 degrees C for suspension of native cells and +4 degrees C for the cells in anabiotic state. Their storage medium should have optimal osmotic pressure and contain NaCl and K+, Mg+ ions. It is recommended to keep halobacteria during one year in a form of suspension in nutrient medium, and during at least 4 years in lyophilized state. Other long-term storage methods: L-drying, freezing at low temperatures, are not recommended for halobacteria.

Culture Media↗
PubMed1992

[The tenacity of Newcastle disease virus (LaSota) in the excrement of laying hens in different housing systems].

The survival time of NDV (LaSota) in the excrement of layers was in summer (winter) 22 and 18 days (26 and 36 days) in two cage houses, 14 and 18 days (36 and 33 days) in two floor-pen houses, as well as 8 days (54 and 68 days) in two dropping store places. By one week staying in battery cages and following the storage in dropping store place after 47 or 50 days NDV (LaSota) could not be reisolated. Besides environment factors, temperature, pH and dry matter was the thermic effect very significant. The comparison of the tenacity of NDV (LaSota) in different housing systems was besides of the quantitative determination of survival time supported through the application of a life time distribution test.

Animals↗
PubMed2003

[A study on sarcosaphagous insects species variety with seasons in Chengdu].

OBJECTIVE: To study the species of sarcosaphagous insects. METHODS: Rabbits were killed and placed outdoors from March to November. Flies that appeared the cadavers were observed and identified. RESULTS: There are five main flies, i.e., Muscadomesticauicina, Lucilia sericata, C. Megacephala, S. fuscicauda, Aldrichiragrahormi. From midtime of April to the beginning of October, Muscadomesticauicina could be seen on the cadvers, however, Aldrichiragrahormi only could be seen before the beginning of May. Otherwise, Lucilia sericata, C. Megacephala, S. fuscicauda could be seen on the cadvers from March to the end of October. After the midtime of November, none of sarcosaphagous flies could be seen on the cadvers. On the other hand, maggots of sarcosaphagous flies could be seen often on the cadvers after adults of sarcosaphagous flies intruding 1 to 4 days, relating to temperature of environment. CONCLUSION: If these flies history of life be studied. it is useful for estimating postmortem interval in Chengdu.

Animals↗
PubMed1998

[Determination of ascorbic acid and its stability of Fructus Hippophae fruit by the method of high-valence iron reduction].

The high-valence iron reduction method was used to determine the ascorbic acid of fructus hippophae fruit. The reduction method had simple, high sensitivity and accuracy in comparison with fluorospectrophotometry or indophenol titration method. Its limit of detection was 0.01 microg/mL, the relative standard deviation and the average recovery was 0.83% (n = 8) and 95.6% (n = 6) respectively. We also researched the influence of the environment factors (temperature, storage period and condition, pH value) on the stability of ascorbic acid in fructus hippophae fruit. The ascorbic acid in fructus hippophae fruit was more stable than thepure ascorbic acid on the same condition of heating (80 C,1 hour), in pH neutral or storing in the refrigerator.

Ascorbic Acid↗
PubMed2005

[Determination of 1-deoxynojirimycin in leaves of Morus alba by high performance liquid chromatography with fluorescence detection].

OBJECTIVE: To develop a high performance liquid chromatographic method for the determination of DNJ in Morus alba leaves with fluorimetric detection after precolumn derivatization with 9-fluorenylmnethyl chlorformate (FMOC-Cl). METHOD: DNJ in Morus alba leaves was extracted with 0.05 mol x L(-1) HCl, reacted with FMOC-Cl, and separated on a HiQSiL C18 column at 250 degrees C. Mobile phase consisted of acetonitrile-0.1% aqueous acetic acid (55:45) with a flow rate of 1.0 mL x min. The fluorescence detector was operated at lambdaEX = 254 nm, lambdaEM = 322 nm. RESULT: A satisfactory separation between DNJ and impurity was obtained. The calibration curve was linear over the concentration range from 0.567 microg x mL(-1) to 34 microg mL(-1), r = 0.9998. The average recovery was 97.2%. The contents of DNJ in M. alba collected in different seasons and grown in different environment were determined. CONCLUSION: The quantity of DNJ in leaves of M. alba is related to the environment factor, temperature and growing period. The method can be used for qualioy control of the medicinal material.

1-Deoxynojirimycin↗
PubMed2005

Body fluid regulation in a simulated disabled submarine: effects of cold, reduced O2, and elevated CO2.

INTRODUCTION: Survivors awaiting rescue aboard a disabled submarine (DISSUB) lacking power and/or environmental control would potentially be exposed to cold and reduced O2 and elevated CO2 levels. We hypothesized that elevated CO2 levels would lead to hormone changes that would mitigate cold and hypoxia-induced body fluid losses. METHODS: Blood was drawn from seven men on three mornings: baseline (21% O2, 0.05% CO2), after 4 d of low O2, cold, and high CO2 (T101; 4 degrees C, 16.75% O2, 2.5% CO2), and following acute withdrawal of cold and high CO2 (T173, 16.75% O2, 0.05% CO2). Total body water (TBW) was measured using deuterium oxide dilution at baseline and at T148. Hormone analyses included atrial natriuretic peptide (ANP), aldosterone (ALDO), and plasma renin activity (PRA). RESULTS: TBW decreased by 0.4 +/- 0.4 L. Water turnover was 3.0 +/- 0.5 L x d(-1). ANP (pg x ml(-1)) was lower (p < 0.05) at T101 (3.46 +/- 1.17) and T173 (4.97 +/- 2.28) vs. baseline (8.19 +/- 3.40). PRA (pg x ml(-1)) was higher (p < 0.05) at T101 (10.43 +/- 4.90) and T173 (14.23 +/- 4.48) vs. baseline (6.81 +/- 3.43). ALDO, serum osmolality, and electrolytes were not different across time. Urine flow was lower at T101 and T173 vs. baseline, and urine osmotic clearance was lower at T173 vs. baseline. Free water clearance did not change across time. DISCUSSION: These data indicate that the combination of cold, low O2, and high CO2 for 5-7 d did not change total body water and hormone changes and urinary measures across the DISSUB were consistent with fluid retention.

Accidents↗