Seep oil and gas in gulf of Mexico slope sediment.

Concentrations in Gulf of Mexico slope sediment of material soluble in methanol and benzene as high as 4.5 percent are shown to be attributable to biodegraded petroleum. Associated carbonate deposits and organic sulfur are the products of the microbial oxidation of petroleum and sulfate reduction. The results of chemical and carbon isotope analyses indicate that high concentrations of hydrocarbon gases, from methane to pentane, are petroleum rather than microbiologically derived. These hydrocarbons, believed to have been produced thermally at depth, probably reached the surface through faults and fractures associated with salt diapirs.

Comparative prevalence of rabies antibodies among household and unclaimed/stray dogs as determined by the immune adherence haemagglutination assay.

The immune adherence haemagglutination assay (IAHA), widely used for human viral disease diagnosis, has been adapted for detection of rabies virus antibodies in dog sera. Rabies virus antibody titres obtained by the IAHA correlated well with those obtained by the currently accepted test for rabies antibody determination, the rapid-fluorescent-focus-inhibition test (RFFIT). Although it is not known if the antibodies detected in IAHA test represent neutralizing antibodies against rabies, IAHA has several advantages over the RFFIT: the IAHA is rapid, requiring about seven hours for results to be available; it is relatively inexpensive and easy to perform; uses reagents commonly available in any routine virology laboratory; and uses inactivated rabies virus, thus eliminating hazards associated with the use of live virus in RFFIT. Using this test we found that rabies antibody titres were significantly higher, and at the same time more prevalent, among household dogs than among the unclaimed/stray dogs. The results re-emphasize the increased hazard associated with unclaimed/stray dogs and the need for vaccination of all dogs.

Effect of age on heat-activated sweat gland density and flow during exercise in dry heat.

Physiological responses of eight postmenopausal older women (age 52-62 yr) and eight younger women (age 20-30 yr) were compared during moderate intensity exercise in a hot dry environment (48 degrees C dry bulb, 25 degrees C wet bulb). The age groups were matched on the basis of maximal O2 consumption (VO2max), body surface area, and body fatness. After heat acclimation the women walked at 40% VO2max for up to 2 h in the hot dry environment while heart rate (HR), rectal temperature (Tre), mean skin temperature (Tsk), whole-body sweating rate (Msw), and local sweating rates (msw; forearm, chest, and scapula) were measured. Additionally, the density of heat-activated sweat glands (HASG) was determined and average sweat gland flow (SGF) was calculated for the scapular area. Although no differences between age groups were found in HR response (when analyzed as percent of maximal HR) or Tsk, the older women had a significantly higher Tre throughout the heat-exercise session. The greater heat storage of the older women may be explained by their significantly lower Msw and msw. There were no differences between the younger and older women in the density of HASG after 30 min; therefore, the lower msw reflects a diminished output per HASG rather than a decrease in the number of sweat glands recruited. The diminished thermoregulatory ability of the older women, unrelated to differences in VO2max, appears to reflect either 1) a diminished response of the sweat glands to central and/or peripheral stimuli, or 2) an age-related structural alteration in the eccrine glands or surrounding skin cells.

Responses of older and younger women to exercise in dry and humid heat without fluid replacement.

Eight older (52 to 62 yr old) post-menopausal and 8 younger (20 to 30 yr old) women were matched with respect to body size, fatness, and maximal oxygen consumption, heat-acclimated, and then exercised at 35 to 40% maximal oxygen consumption in a warm-humid (37 degrees C, 60% relative humidity) environment. Results were compared with similar data from a hot-dry (48 degrees C, 15% relative humidity) environment. No fluid replacement was provided during either of these sessions. In each environment, the older women stored more heat as evidenced by a higher rectal temperature response, but there were no inter-group differences in skin temperature or percent maximal heart rate. Four of the older women were unable to complete either the hot-dry or the warm-humid exposure, although they completed the full 2 h during acclimation sessions when water was provided ad libitum. In the hot-dry environment, the younger women's whole body and local sweat rates were significantly higher than those of the older women; in the warm-humid environment, there was no age-related difference in sweat rate. When local skin temperature and wettedness were artificially elevated, both groups exhibited the same pattern and rate of sweating. Percent decrease in plasma volume was greater for the older women in both conditions, but significantly so only in the warm-humid environment.(ABSTRACT TRUNCATED AT 250 WORDS)

Levamisole potentiation of antigen specific lymphocyte blastogenic response in Brucella abortus exposed but nonresponsive cattle.

Incubation of Brucella abortus (field strain) infected and strain 19 vaccinated bovine peripheral blood lymphocytes with B. abortus antigen and levamisole caused a consistently significant increase in [3H] thymidine uptake when compared to cultures without levamisole. Levamisole did not potentiate B. abortus-induced blastogenic response of lymphocytes from non-exposed cattle. A dose response study showed that 10 micrograms/culture induced maximum potentiation of B. abortus-induced lymphocyte stimulation. Using the 10 micrograms/well concentration of levamisole, further studies were conducted to determine the net potentiation of the blastogenic responses in lymphocytes from B. abortus (field strain) infected cattle. B. abortus strain 19 vaccinated but nonresponsive and non-exposed cattle. Levamisole significantly potentiated the B. abortus-induced lymphocyte blastogenesis in lymphocytes from unresponsive cattle.

Application of indomethacin as a potentiator of lymphocyte blastogenesis in Brucella abortus exposed cattle.

Lymphocytes from Brucella abortus field strain infected, strain 19 vaccinated, non-exposed and field strain infected, but immunologically unresponsive cattle were incubated with B. abortus antigen and indomethacin. There were significant increases (P less than 0.005) in the blastogenic responses, as measured by [3H] thymidine uptake, in cultures with indomethacin as compared to cultures without indomethacin. Lymphocyte blastogenic responses to B. abortus antigen were potentiated by indomethacin in both B. abortus exposed and non-exposed cultures. However, potentiation of sensitized lymphocyte blastogenic responses by indomethacin was significantly greater (P less than 0.005) than that in non-exposed lymphocytes. Additionally, indomethacin significantly potentiated Brucella-induced lymphocyte blastogenic responses in lymphocytes from anergic cattle.

Synthesis and structure-activity relationships of some 6 beta-acrylamido penicillins.

Syntheses are described for penicillins (4b approximately 4i, 5a and 5b) which possess a 6 beta-(2-heteroaryl-3-substituted)-propenamido side-chain of fixed geometry. In vitro results for these compounds against a range of Gram-positive and Gram-negative bacteria showed in most cases good stability against both penicillinase and TEM-1 beta-lactamase; analogues (4b approximately 4i) bearing a 2-(2-aminothiazol-4-yl) unit showed the best intrinsic activity, the cyclohexyl compound (4b) being the most promising. The 1-acetoxyethyl ester (6) of 4b was also prepared; in experimental animal studies the in vivo properties of this compound compared favourably with cefuroxime axetil and are reported together with selected in vivo data for the other compounds.

Longitudinal studies of naturally acquired Brucella abortus infection in sheep.

Naturally acquired Brucella abortus infections were studied during consecutive pregnancies in eight sheep and in their lambs over a period of 40 months to evaluate epizootiologic aspects of natural infection in sheep. Brucella abortus was isolated from the ewes following 16 of 26 natural terminations of pregnancy: from 5 of 6 ewes in the first year, from six of eight ewes in the second year, from two of six ewes in the third year, and from three of six ewes in the fourth year. Vaginal swab samples and milk samples were the most consistent source of the brucella organisms. Brucella abortus was isolated from three ewes when standard tube test seroagglutination titers were less than 1:100. In contrast, results of supplemental tests (card, 2-mercaptoethanol, complement-fixation, and Rivanol) remained positive during the study. During the 40 months, B abortus was isolated from 4 of 4 aborted fetuses, 2 of 5 stillborn lambs, 10 of 37 living lambs, and as an indicator of continuing infection, from 6 of 12 lambs born during the fourth year. Although B abortus has a definite host preference for cattle, this study demonstrated that under appropriate management conditions, sheep may be naturally infected and may remain infected for more than 40 months. Epizootiologic evaluation of all factors, including husbandry practices and exposure potential, should be utilized in determining the need to test other species that may have been exposed to cattle infected with B abortus.

Cell-mediated immune responses in cattle adult-vaccinated with Brucella abortus strain 19 and in cattle infected with Brucella abortus field strain.

Cell-mediated immune responses in cattle adult-vaccinated with Brucella abortus strain 19, cattle infected with B abortus field strain, and nonexposed cattle were studied by an in vitro lumphocyte-stimulation test (LST). Lymphocytes were prepared from peripheral bovine blood by the Ficoll-diatrizoate technique, and results were assayed for [3H]thymidine incorporation into DNA by liquid scintillation spectrometry. Serotests and bacteriologic isolation attempts were conducted simultaneously with LST. Lymphocytes from cattle infected with field strains had significantly (P = 0.01) higher specific lymphocyte-stimulation inexposed controls. The LST, the serum standard-tube agglutination test (STT), the Rivanol (RIV) test, and the complement-fixation (CF) test correctly classified cattle from which field strains and strain 19 of B abortus were isolated. The LST was negative in cattle vaccinated with B abortus strain 19 (nonshedding), but the three serotests had many false-positive reactions. The CF test had the least false-positive reaction, followed by the RIV test, and the STT was the least specific. Well before the three serotests became positive, the LST was positive in samples from some cattle during the incubation period of the infection. There was little or no correlation between cell-mediated immune responses (as measured by LST) and serum antibody responses (as measured by STT, RIV test, and CF test) in vaccinated but culture-negative cattle and in some nonvaccinated cattle during the incubation period.

Cell-mediated immune responses in cattle vaccinated with Brucella abortus strain 19 vaccine and nonexposed control animals of the same age.

Cell-mediated immune (CMI) responses in cattle vaccinated with Brucella abortus strain 19 vaccine during calfhood were studied by an in vitro lymphocyte stimulation assay. Cattle were grouped in six groups according to the age after vaccination, and CMI responses of these groups, as well as of individual animals, were compared. Lymphocytes were prepared from peripheral blood of these cattle by the Ficoll-diatrizoate technique. Lymphocytes were then cultured with B abortus-soluble antigen. Culture results were assayed for [3H]thymidine incorporation into DNA by liquid scintillation spectrometry. On a group basis, B abortus-soluble antigen induced lymphocyte stimulation responses in lymphocytes from all the groups, except the sixth group which contained animals that had been vaccinated the longest time (18 to 24 months before this experiment). Animals that had been vaccinated for 3 to 6 months had the highest lymphocyte stimulation response. Seroagglutination tests were conducted simultaneously with the lymphocyte stimulation test, but there was no apparent correlation between the concentrations of humoral antibodies and the CMI responses as measured by in vitro specific lymphocyte stimulation. The lymphocyte stimulation test exhibited significantly higher specificity (P less than 0.005) than the serologic tests.

Cell-mediated immune responses in swine from a herd infected with Brucella suis.

Cell-mediated immune (CMI) responses in swine naturally infected with Brucella suis biotype 3, swine suckling an infected sow and Brucella-noninfected swine were studied by an in vitro lymphocyte transformation procedure. The antigen used was a soluble antigen prepared from killed cells of B suis biotype 3. Lymphocytes were prepared from peripheral swine blood by the Ficoll-Hypaque technique, suspended in RPMI-1640 medium (1.5 X 10(6) lymphocytes/ml), cultured with B suis-soluble antigen or concanconcanavalin A, and incubated for 6 days. Sixteen hours prior to termination of incubation, cultures were labeled with 1 muCi of [3H]thymidine and, after harvesting, were assayed for [3H]thymidine incorporation into DNA by liquid scintillation spectrometry. Agglutination tests were conducted on sera collected simultaneously with samples for lymphocyte-stimulation tests. The B suis-soluble antigen elicited specific stimulation in lymphocytes from infected pigs. On a group basis, there was high correlation between the amount of serum antibodies and specific lymphocyte stimulation, but on an individual animal basis, there was little correlation of the results of both systems in infected swine. There was high correlation between recovery of Brucella from the tissues of animals and the degree of CMI response. Suckling pigs from an infected sow did not develop CMI responses, as measured by our system.

Studies on in vitro lymphocyte stimulation assay in cattle naturally infected with Brucella abortus and in cattle vaccinated with strain 19.

Cell-mediated immune responses of cattle in infected herds vaccinated with Brucella abortus, strain 19, and of nonexposed controls were studied by an in vitro lymphocyte stimulation test (LST). Brucella abortus soluble antigen was used as a specific stimulator of lymphocytes. Lymphocyte suspensions were prepared from peripheral blood of cattle by the Ficoll-diatrizoate technique. Cultures were labeled with [3H]thymidine and were assayed for [3H]thymidine incorporation into DNA by liquid scintillation spectrometry. Seroagglutination tests and cultures from Brucella were conducted simultaneously with LST. Brucella abortus soluble antigen induced significantly higher (P less than or equal to 0.005) lymphocyte stimulation responses in lymphocytes from cattle infected with B abortus than in lymphocytes from cattle vaccinated with strain 19 or from nonexposed controls. There was a significant P = agreement in results of LST and seroagglutination tests in infected cattle. Among seropositive-vaccinated cattle and controls, the LST was negative.

Specific lymphocyte stimulation in cattle naturally infected with strains of Brucella abortus and cattle vaccinated with Brucella abortus strain 19.

Cell-mediated immune responses in cattle naturally infected with strains of Brucella abortus and in cattle vaccinated with B abortus strain 19 during calfhood were studied by an in vitro lymphocyte-stimulation procedure. Lymphocytes were prepared from peripheral bovine blood by the Ficoll-diatrizoate technique, suspended in RPMI-1640 medium (1.5 X 10(6) lymphocytes/ml), cultured with B abortus-soluble antigen or phytohemagglutinin, and incubated for 6 days. Sixteen hours prior to termination of incubation, cultures were labeled with 1 muCi of [3H]thymidine (3HdT) and, after harvesting, assayed for 3HdT incorporation into DNA by liquid scintillation spectrometry. Lymphocytes from cattle with bacteriologically confirmed isolation of B abortus underwent a significantly higher lymphocyte stimulation with B abortus-soluble antigen than did cattle vaccinated with B abortus strain 19 during calfhood (P less than 0.005). Standard seroagglutination tests were conducted simultaneously with lymphocyte-stimulation tests, but there was no apparent correlation between levels of humoral antibodies and the cell-mediated immune responses as measured by in vitro specific lymphocyte stimulation.

Kinetics of in vitro bovine lymphocyte immunostimulation with a Brucella abortus antigen.

A Brucella abortus-soluble antigen was investigated, using in vitro assay of lymphocyte immunostimulation, to determine which concentration of this antigen and which period of incubation of the lymphocyte cultures would induce maximum specific lymphocyte immunostimulation as an additional method for further study of B abortus infection in cattle. Soluble antigen was prepared from autoclaved cells of B abortus strain 1119-3. Peripheral blood lymphocytes were obtained from cattle infected with B abortus and from healthy control cattle not infected with B abortus. The lymphocytes were prepared by the Ficoll-Hypaque density gradient technique, suspended in RPMI 1640 medium (1.5 X 10(6)/ml), cultured with several dilutions of soluble antigen, and incubated. Prior to termination of incubation, cultures were labeled with 1 muCi of [3H]thymidine and, after harvesting, assayed for [3H]thymidine incorporation in DNA by a liquid scintillation spectrometer. Maximum specific immunostimulation of lymphocytes from B abortus-infected cattle was induced in this assay system with 6 days' incubation and 22 microgram of protein/ml/1.5 X 10(6) lymphocytes, using protein content to express concentration of soluble antigen in this system.

Severe pruritus associated with lymphoma in a dog.

A dog with chronic pruritus that was refractory to antibiotic, corticosteroid, and antihistamine treatment was found to have lymphoma involving the spleen and associated lymph nodes. Pruritus rapidly resolved on removal of the tumor and recurred on reappearance. The association of generalized pruritus with an occult malignant process may be difficult to assess, but after excluding the more common causes of pruritus, a visceral malignancy should be considered.