Isolation of fungi from bats of the Amazon basin

A total of 2,886 bats captured in the Amazon Basin of Brazil were processed for the isolation of fungi. From the livers, spleens, and lungs of 155 bats (5.4%), 186 fungal isolates of the genera Candida (123 isolates), Trichosporon (26 isolates), Torulopsis (25 isolates), Kluyveromyces (11 isolates), and Geotrichum (1 isolate) were recovered. Seven known pathogenic species were present: Candida parapsilosis, C. guilliermondii, C. albicans, C. stellatoidea, C. pseudotropicalis, Trichosporon beigelii, and Torulopsis glabrata. Twenty-three culture-positive bats showed identical fungal colonization in multiple organs or mixed colonization in a single organ. The fungal isolation rates for individual bat species varied from 1 fungus per 87 bats to 3 fungi per 13 bats, and the mycoflora diversity for members of an individual fungus-bearing bat species varied from 16 fungi per 40 bats to 7 fungi per 6 bats. Of the 38 fungal species isolated, 36 had not been previously described as in vivo bat isolates. Of the 27 culture-positive bat species, 21 had not been previously described as mammalian hosts for medically or nonmedically important fungi.     

Beneficial effects of n-hexane bark extract of Onosma echioides L. on diabetic peripheral neuropathy

Onosma echioides Linn (Boraginaceae) is the most frequently used curative herb widely used for kidney obstruction, sciatic pain, and gout. The present study was designed to investigate the therapeutic effects of n-hexane bark extract of O. echioides (OE) L. root in vivo against Streptozotocin-induced diabetic neuropathy in SD rats. For in vivo activity, the experiment was categorized into five different groups (n = 5). Group-I was considered as nondiabetic/normal control (NC) treated with 0.5% carboxymethyl cellulose (CMC), Group II as diabetic control, Group-III, IV, and V served as diabetic treated with OE 50, OE 100, and pregabalin at a dose of 50, 100, and 10 mg/kg body weight, orally, respectively. Body weight, blood glucose, oral glucose tolerance test, behavioral studies (motor coordination test, thermal hyperalgesia, cold allodynia, locomotor activity, oxidative biomarkers (thio barbituric acid reactive substances [TBARS], superoxide dismutase [SOD], glutathione [GSH], and catalase), and histopathology of the sciatic nerve were performed. Treatment with OE showed a dose-dependent increase in neuroprotective activity by improving the myelination and decreasing the axonal swelling of nerve fibers. The verdicts of behavioral activities showed a remarkable effect on animals after the treatment of extract and standard drug pregabalin. In conclusion, our findings supported the traditional application of OE and explored its importance in the management of diabetic neuropathy. Additional clinical experiments may provide novel therapeutic drugs for diabetes and its complications.     

The natural history ofPetrobia (Tetranychina) harti (Ewing) andPetrobia (Mesotetranychus) tunisiae Manson (Acari: Tetranychidae) in the laboratory

Petrobia harti (Ewing) developed more rapidly, deposited more eggs and lived longer onOxalis corniculata than onO. articulata. No development took place on several other recorded host plants. In the field this mite was most abundant during early summer. Males made up less than 10% of the population, and no diapause eggs were seen in the field.Petrobia tunisiae Manson developed on various winter Gramineae, produced about 17 non-diapause eggs during its first generation and mostly diapause eggs in the second. A few diapause eggs kept in the laboratory and dipped in chloroform hatched even after 3 years. A summer diapause is postulated for this species.     

Bulb mite,Rhizoglyphus robini (Astigmata: Acaridae) as an experimental animal

Rhizoglyphus robini Claparède (Acari: Astigmata: Acaridae) is proposed as a model laboratory animal for biological, ecological, physiological and toxicological studies. The mite is easy and inexpensive to rear, quite fecund, convenient to manipulate, and may rapidly be raised to gram quantities. Examples are presented of its use in soil pest ecology and control studies, and in physiological, biochemical and toxicological investigations. Efforts to explore the induction of detoxification systems by various chemicals, and a demonstration of its control by solarization, are also described.     

Control of ammonium concentration in Escherichia coli fermentations

A control system has been devised for the maintenance of stable ammonium concentrations throughout a fedbatch fermentation. The control system is based on an ammonia gas-sensing electrode that monitors a pH-adjusted effluent stream from the fermentor. To overcome the time lag between the fermentor and the electrode, feedback control included metered flows of ammonium to both the fermentor and the electrode vessel. The system was used to study the growth of Escherichia coli B (ATCC 11303) at controlled ammonium concentrations of 5 to 200mM. Apparent specific growth rates, biomass and protein production, and glucose yields were essentially constant from 5 to 170mM. Above 170mM ammonium growth was inhibited. As ammonium concentration decreased from 170 to 5mM, ammonium yields increased from 1 to 24 g cell dry wt/g ammonium utilized. The results demonstrate that control of ammonium concentrations at levels so low that ammonium would be exhausted in batch fermentations can significantly increase overall ammonium yields.     

Effects of carbon dioxide concentration on anaerobic fermentations of Escherichia coli

Summary The effect of dissolved carbon dioxide concentration in the anaerobic growth of Escherichia coli was investigated. E. coli was grown anaerobically with the dissolved CO₂ concentration controlled over the range from 8x10^-6 M to 3.7x10^-2 M in the liquid phase. The maximum specific growth rate was 0.75h^-1 at 1.3x10^-3 M CO₂ and the maximum yield of cells on glucose was 0.32 at 1.75x10^-4 M CO₂. The maximum specific growth rate occurs close to the concentration of CO₂ prevalent in the mammalian gut where E. coli naturally resides.Alberta Research Council contribution, paper 1364     

Intracellular pH and the cell cycle of mitogen-stimulated murine lymphocytes

Rapidly proliferating, polyclonally stimulated mouse spleen lymphocytes were separated by density-gradient unit-gravity sedimentation. The following measurements were made on each fraction: the average intracellular water volume, the distribution of DNA content by flow microfluorometry, the rate of ³H-thymidine incorporation, and the intracellular pH. Fractions of cells with a small average intracellular volume were predominately in G0 or G1 phase of the cell cycle, while fractions of larger cells had higher proportions of cells in S or G2. Multiple regression analysis of the data for both T and B lymphocytes indicated that the intracellular pH of cells in G0, G1, or G2 is around pH 7.2, and that the intracellular pH of cells in S phase of the cell cycle is around pH 7.4.     

The predator guild associated withAceria litchii (Acari: Eriophyidae) in Australia and China

Lychees were surveyed in Queensland, Australia and in Guangdong Province and Hainan Island China, for natural enemies of the lychee erinose mite,Aceria litchii (Keifer), one of the most serious pests of lychee in Australia. A guild of seventeen predators, including ten species of phytoseiid mites, was associated with lychee erinose in Queensland. Six other predaceous mite species and a cecidomyiid larva,Arthrocnodax sp. were also part of the complex. Despite the apparent predation of most of the seventeen species recorded in Queensland onA. litchii, the pest continues to cause major problems. In China, whereA. litchii is a relatively minor pest, nine phytoseiid species were collected in lychee orchards. The value of introducing additional predators to Australia, especially from China, is discussed.     

The effect of light levels on daily patterns of chlorophyll fluorescence and organic acid accumulation in the tropical CAM treeClusia hilariana

Sandy plains are characteristic of the coastal region of Brazil. We investigated the diel patterns of changes in organic acid levels, leaf conductance and chlorophylla fluorescence for sun-exposed and shaded plants ofClusia hilariana, one of the dominant woody species in the sandy coastal plains of northern Rio de Janeiro state. Both exposed and shaded plants showed a typical CAM pattern with considerable diel oscillations in organic acid levels. The degradation of both malic and citric acids during the midday stomatal closure period could lead to potential CO₂ fixation rates of 28 mol m^-2 s^-1 in exposed leaves. Moreover, exposed leaves exhibited large increases in total non-photochemical quenching (q_N) accompanied by a substantial decrease in effective quantum yield during the course of the day. However, these potential high rates of CO₂ fixation and the increases inqn of exposed plants were not enough to maintain the primary electron acceptor of photosystem II (q_A) in a low reduction state, similar to that of shaded plants. As a result, there was a moderate increase in the reduction state of q_A throughout the day. Most of the decline in photochemical efficiency of exposed leaves ofC. hilariana was reversible, as evidenced by the high levels of pre-dawn potential quantum yields (F_v/F_m) and their rapid recovery after sunset. However, the depletion of the organic acid pool in the afternoon resulted in an accentuated subsequent drop in F_v/F_m, suggesting that prolonged periods of water stress accompanied by high irradiance levels may expose plants ofC. hilariana in unprotected habitats to the danger of photoinhibition.     

Prescribing of psychoactive drugs for chronically ill elderly patients.

The prescribing of psychoactive drugs for 1431 chronically ill elderly patients being assessed for long-term institutional or community care was surveyed. Psychoactive drugs had been prescribed for about one quarter of the patients; benzodiazepines were the most frequently prescribed group. Judging from the extensive prescribing of flurazepam and chloral hydrate, commonly used hypnotics, the main reason psychoactive drugs were prescribed was to provide night-time sedation. Antidepressants and drugs promoted as useful in improving cognitive function were infrequently prescribed. Commendable prescribing practices included the infrequent use of "cerebral vasodilators" and barbiturates. Questionable prescribing practices included the infrequent use of tricyclic antidepressants in severely depressed patients and the use of tranquilizers in patients described by their attending physician as markedly or extremely withdrawn.