Chironomid egg masses as a natural reservoir of Vibrio cholerae non-O1 and non-O139 in freshwater habitats.

Cholera is a diarrheal disease caused by the gram-negative bacterium Vibrio cholerae, and an estimated 120,000 deaths from cholera occur globally every year. The natural reservoir of the bacterium is environmental. A recent report indicated an association between V. cholerae and chironomid egg masses. Chironomids, the "non-biting midges" (Diptera; Chironomidae), are the most widely distributed and frequently the most abundant insects in freshwater. Females attach egg masses, each containing hundreds of eggs encased in a layer of gelatin, to the water's edge where bacteria are abundant and may encounter the nutrient-rich substrate. Here we report the isolation of non-O1 and non-O139 V. cholerae from chironomid egg masses from different freshwater bodies in Israel, India, and Africa. In a yearly survey in Israel, chironomid populations were found to peak biannually, and it seemed that those peaks were followed by subsequent bacterial growth and disappearance during the winter in the Mediterranean region. The bacterial population rose as water temperature surpassed 25 degrees C. Thirty-five different serogroups of V. cholerae were identified among the bacteria isolated from chironomids, demonstrating population heterogeneity. Two strains of V. cholerae O37 and O201 that were isolated from chironomid egg masses in Zanzibar Island were NAG-ST positive. Our findings support the hypothesis that the association found between chironomids and the cholera bacteria is not a rare coincidence, indicating that chironomid egg masses may serve as yet another potential reservoir for V. cholerae.

Administration of recombinant human interleukin 12 to chronically SIVmac-infected rhesus monkeys.

With the demonstration that interleukin 12 can enhance natural killer (NK) cell activity and drive CD4+ lymphocytes toward T helper type 1 (Thl) responses, there is a strong rationale for exploring the use of this cytokine as an immunomodulatory therapy in HIV-1-infected individuals. To assess its potential safety and effects on both immune and virologic aspects of HIV-1 infection, recombinant human IL-12 (rhIL-12) was assessed in rhesus monkeys chronically infected with the simian immunodeficiency virus of macaques (SIVmac). The activity of rhIL-12 on rhesus monkey lymphocytes was confirmed with the demonstration that peripheral blood lymphocyte lysis of the NK-sensitive cell line Colo was enhanced by this recombinant cytokine. Further, rhIL-12 was shown to induce interferon-gamma production by rhesus monkey lymphocytes in vitro. Then, in separate studies, two treatment regimens of rhIL-12 were assessed in SIVmac-infected monkeys: a low-dose regimen (0.1 microg/kg, daily for 4 weeks) and a high-dose regimen (2.5 microg/kg, every 3-4 days, for 3 weeks). Both rhIL-12 treatment regimens were well tolerated by these virus-infected animals. The high-dose regimen of rhIL-12 induced transient decreases in circulating lymphocytes in the SIVmac-infected monkeys. Furthermore, no changes in lymphocyte-associated SIVmac DNA or SIVmac plasma RNA levels were seen in the treated monkeys. These studies indicate that short-term treatment with rhIL-12 is well tolerated and causes no measurable changes in virus load in chronically SIVmac-infected rhesus monkeys.

Southampton University Hospitals NHS Trust: our approach to performance management.

Southampton University Hospitals Trust has developed a performance management strategy which is improving service quality, overcoming interdepartmental blockages and delivering significant savings with greater departmental ownership and commitment. The strategy also offers a solution to the age-old problem of if and when to market test by doing this only when it is apparent the inhouse team cannot deliver the required level of performance. This is achieved by agreeing the initiating key targets to reach or improve on high levels of performance using a variety of techniques including benchmarking, value management and external technical advice.

Lateral order in mixed lipid bilayers and its influence on ion translocation by gramicidin: a model for the structure-function relationship in membranes.

The temperature-composition phase diagram of dimyristoylphosphatidylcholine and dipentadecylphosphatidylglycerol (DiC15PG) was determined by mass densitometry. For a mixture containing 30 mol% DiC15PG, the homogeneous distribution of the 2 components is demonstrated in the fluid state at T = 35 degrees C by small-angle neutron scattering in combination with the inverse contrast variation method. By the same technique, the coexistence of fluid and condensed phases at T = 23.3 degrees C could be shown in agreement with the densitometric data. Furthermore, it is demonstrated that Ca++ induces, even at T = 35 degrees C, separation into 2 fluid phases. A corresponding phase separation is found in bimolecular lipid membranes ("black films") by analysis of the single-channel conductance fluctuations of gramicidin A incorporated into an equimolarly mixed membrane of neutral lecithin and charged phosphatidic acid. The results are discussed as primary examples on the model-membrane level for the important structure-function relationship of biomembranes.

Effect of hyperthermia upon gamma-ray induced crossing-over in an excision repair deficient male Drosophila melanogaster.

Hyperthermia of 1 h at 38 degrees C did increase gamma-ray induced crossing-over in meiotic cells of male larvae and adults. However, there was considerably less effect of the heat treatment upon radiation induced crossing-over (a chromosome breakage event) in an excision repair mutant y mei-9a.

Effects of hyperthermia on radiation-induced chromosome breakage and loss in excision repair deficient Drosophila melanogaster.

Hyperthermia increased radiosensitivity with respect to gamma-ray induced chromosome loss and breakage in all stages of spermatogenesis in the wild type Oregon R strain of Drosophila melanogaster, whereas hyperthermia increased radiosensitivity to a lesser extent in cn mus (2) 201D1, an excision repair mutant with 0 per cent excision capacity and in mus (3) 308D1, a strain with 24 per cent excision capacity. The differences in hyperthermia-induced radiation sensitivity between the excision repair mutants and the wild strain may be due to the hyperthermia affecting the excision repair mechanism, suggesting that one of the possible mechanisms involved in hyperthermia-increased radiosensitivity is an effect on excision repair.

Hyperthermia increases chromosome breakage and loss induced by fission neutrons in Drosophila melanogaster.

Pretreatment with hyperthermia did significantly increase the breakage and chromosome loss induced by 0.85-MeV fission neutrons from the JANUS biological research reactor in spermatozoa, early and late spermatids and spermatocytes. Radiation-induced breakage of chromosomes was also enhanced by hyperthermia in early spermatogonia.

Effect of hyperthermia on radiation-induced chromosome loss in female Drosophila melanogaster.

Three-day-old adult females of mutagen sensitive mutants: mus (1)101D1, mus(1)102D2, mus(1)103D1, mus(1)104D1, mus(1)105D1, mus(3)302D2; meiotic mutants: mei-9D2, mei-9D3, mei-218, and controls st, and w, were subjected to 38 degrees C for 1 hour and 1200R of gamma rays, brooded daily, and nondisjunction and the loss of X chromosomes determined. This was done in an attempt to gain more information on the hyperthermia sensitization of radiation-induced damage. In several strains the hyperthermia treatment sensitized immature class-1 oocytes--the most radiation-resistant stage--to radiation-induced chromosome loss. This class of oocytes is believed to have the greatest number of repair enzymes, and supports the hypothesis that hyperthermia increases radiation-induced genetic damage by interference with repair enzymes. The mature oocytes, which are believed to lack repair enzymes (stage 14), were the most sensitive to heat treatment and radiation. Hyperthermia failed to increase radiation-induced chromosome loss in the meiotic mutants. Hyperthermia may affect excision repair. There was no clear-cut correlation between other defective DNA pathways and influence of hyperthermia on radiation-induced chromosome loss in Drosophila females. The failure of hyperthermia to increase radiation-induced chromosome loss in meiotic mutants may indicate that radiation sensitization by hyperthermia also may be due to interference with chromosome segregation.

Response of mutagen-sensitive Drosophila melanogaster to hyperthermia and radiation.

In an attempt to understand the mechanism of hyperthermia sensitization of radiation-induced damage, males of 5 mutant mutagen-sensitive strains: mei-41A1, w mus(1)101D1, w mus(1)104D1, y mei-9a, and w mus(1)102D2, representing at least 3 different defects in the DNA-repair pathways were exposed to hyperthermia (38 degrees C for 1 h) and to 1000 R of X-rays. In all of the mutagen-sensitive strains, the radiation-induced dominant lethals were enhanced by the hyperthermia treatment in the 6--8 day brood, which included the meiotic division at the time of radiation, and in the postmeiotic broods. The radiation-induced recessive lethals were also significantly increased by hyperthermia treatment in all the mutagen-sensitive mutants except mei-41A1 in 4--6 day brood. However, mei-41A1 males produced a significant increase of lethals in earlier broods, 0--2 and 2--4 day. The hyperthermia which apparently sensitizes radiation-induced damage by inhibiting DNA and probably chromosome-repair systems, is not specific, at least for 3 different Drosophila repair pathways.

Hyperthermia and radiation-induced dominant lethals and chromosome loss in female Drosophila melanogaster.

The hyperthermia treatment, 38 degrees C for 1 hour significantly increased the dominant lethals induced by 1000R of X-rays in immature oocytes. The viability and chromosome loss in mature eggs were affected by either heat treatment or radiation. Hyperthermia treatment given before radiation exposure also significantly increased radiation-induced loss of the X chromosome in immature oocytes. Heat treatment did not increase radiation-induced nondisjunction of the chromosomes.

Ultrasonic evaluation of extremity soft-tissue lesions with arthrographic correlation.

Diagnostic ultrasound is a fast and accurate method to detect extremity soft-tissue lesions, including popliteal (Baker) cysts, abscess, rupture of the suprapatellar bursa, peripheral artery aneurysms, and soft-tissue tumors.

Failure of chronic exposure to nonthermal FM radio waves to mutate Drosophila.

A stock of Drosophila sc VI - YS/y ac oc ptg - YL/y ac oc ptg - YL/y sc S1 B In49 ct ns v sc8 that accumulated the recessive lethals on the X chromosome was exposed to a frequency of 98.5 MHz (wave length 3.35 m) and a field strength of 0.3 V/m. The flies were kept near the base of the 300-ft antenna of a 50,000 watt transmitter for 32 weeks. There was no significant difference in the percentage of lethals between the stock exposed to 4,020 hours of nonthermal FM radio waves and the controls.