Differentiation of Salmonella senftenberg into biogroups

Ninety-six strains of Salmonella senftenberg, isolated between 1984 and 1986 from different parts of England and Wales, were tested for their biochemical reactions and biotyped according to the method of Duguid and others (1975). Nine biogroups were identified on the basis of their metabolism of L-tartrate, D-tartrate, Bitter's xylose and Stern's glycerol. In addition, fumaric, oxalic, succinic, glutaric, malonic, maleic, L-malic, L-aspartic, lactic and formic acids were used but did not increase the discrimination. Three biogroups (7, 2 and 5) accounted for 79 per cent of the cultures examined.

Interaction of water activity and temperature on aflatoxin production by Aspergillus flavus and A. parasiticus in irradiated maize seeds

The effects of aw (0.90, 0.95, 0.98) and temperature (25 degrees C, 30 degrees C, 35 degrees C) on aflatoxin production by Aspergillus flavus and Aspergillus parasiticus growing on irradiated maize seeds, were examined. Highest levels of aflatoxin were produced by A. parasitious at 25 degrees C and 0.98 aw and by A. flavus at 30 degrees C at 0.95 and 0.98 aw. At 0.90 aw toxin production was consistently low for both species at all temperatures. Temperature cycling of A. flavus between 25 degrees C and 35 degrees C each for 12 h resulted in higher aflatoxin synthesis than when incubated either at 25 degrees C or 35 degrees C.

"Hugging balloons" through a single 8-French guide: salvage angioplasty with lytic therapy in the infarct vessel of a 40-year-old man

We report the a case of hugging balloons through an 8-French guiding catheter to stabilize an ectatic right coronary artery following failed thrombolytic therapy in the setting of acute myocardial infarction. Angiographic follow-up at 1 wk and 6 mo revealed persistent vessel patency.

Analyses of multinomial mixture distributions: new tests for stochastic models of cognition and action

Mixture distributions are formed from a weighted linear combination of 2 or more underlying basis distributions [g(x) = sigma j alpha j fj(x); sigma alpha j = 1]. They arise frequently in stochastic models of perception, cognition, and action in which a finite number of discrete internal states are entered probabilistically over a series of trials. This article reviews various distributional properties that have been examined to test for the presence of mixture distributions. A new multinomial maximum likelihood mixture (MMLM) analysis is discussed for estimating the mixing probabilities alpha j and the basis distributions fj(x) of a hypothesized mixture distribution. The analysis also generates a maximum likelihood goodness-of-fit statistic for testing various mixture hypotheses. Stochastic computer simulations characterize the statistical power of such tests under representative conditions. Two empirical studies of mental processes hypothesized to involve mixture distributions are summarized to illustrate applications of the MMLM analysis.

Cardiovascular effects of nasotracheal intubation

Intubation time, arterial pressure, heart rate and arterial oxygen saturation during nasotracheal intubation effected with the Macintosh laryngoscope blade were compared with those during orotracheal intubation. The 60 patients studied received a standardised general anaesthetic and were randomly allocated to one of two groups immediately before tracheal intubation. The mean nasal intubation time (33.2 seconds) was significantly greater than mean oral intubation time (14.8 seconds). The mean arterial pressure changes in the nasal group were significantly greater and more prolonged than in the oral group. The mean heart rate in the nasal group was significantly lower than in the oral group during the first minute after intubation, after which heart rates were similar. There were no significant differences between the two groups with regard to arterial oxygen saturation levels at any stage.

Effect of surface sterilization, fumigation and gamma irradiation on the microflora and germination of barley seeds

Sodium hypochlorite (NaOCl) and mercuric chloride (HgCl2) surface sterilization, methyl bromide and propylene oxide fumigation and gamma irradiation treatments were compared for their effectiveness in killing microorganisms on or within barley seeds. Surface sterilization with 12.5, 25 or 50% (v/v) NaOCl for 5, 15 or 30 min, decreased Fusarium spp., Epicoccum purpurascens, and Bacillus spp. but did not kill Alternaria alternata. However, surface sterilization with 0.1 or 0.2% (w/v) HgCl2 for 3 min significantly decreased A. alternata, Fusarium spp. and E. purpurascens but Bacillus spp. were only killed by 0.3% (w/v) HgCl2 used for 10 min, which also decreased seed germination. Aspergillus flavus inoculated onto barley seeds as spores, was completely killed by surface sterilization with NaOCl but not with HgCl2, while Fusarium culmorum was killed by both NaOCl and HgCl2 treatments. Fumigation with methyl bromide yielding a concentration-time product of 3000 mg h l-1 or with propylene oxide giving a concentration-time product of 2400 mg h l-1 eliminated all filamentous fungi but Bacillus spp. and yeasts survived, and both treatments adversely affected seed germination. Gamma irradiation at a dose of 4 kGy eliminated most Alternaria, Fusarium and Epicoccum spp. but a dose of 12 kGy was required to kill Bacillus spp., yeasts and Aureobasidium pullulans. Germination was improved slightly up to a dose of 8 kGy but gradually decreased with increase in dosage to 15 kGy of gamma irradiation.

Comparison of two methods of fibrescope-guided tracheal intubation

We have compared intubation time and cardiovascular effects of fibrescope-guided orotracheal intubation aided by the Berman 11 Intubating Airway with those of the tongue traction method of fibreoptic intubation and with conventional Macintosh intubation. We studied 75 patients who received a standard general anaesthetic which included non-depolarizing neuromuscular block; they were allocated randomly to one of the three groups immediately before intubation. The mean time required to effect Berman airway intubation (34.9 s) was similar to that required for tongue traction intubation (35.3 s) and significantly greater than that required for Macintosh intubation (11.7 s). The cardiovascular responses to both types of fibreoptic intubation were significantly greater and more prolonged than those of Macintosh intubation. There were no significant differences between the responses to the two fibreoptic techniques. Haemodynamic effects should be considered when performing fibrescope-guided tracheal intubation under general anaesthesia and, when necessary, appropriate measures should be taken to minimize them.

Use of bar codes in inpatient drug distribution

The development and operation of a prototype inpatient drug distribution system that uses bar codes is described, and the impact of bar coding on the cassette-filling and verification process is summarized. A prototype pharmacy dispensing site was created to function in parallel with an existing satellite dispensing site that served 78 general medical-care beds. Supplemental labels encoded with an 11-digit unique product identification number, a 5-digit expiration date, and a 6-character lot number were generated and affixed to all unit dose packages dispensed from the prototype pharmacy site. The unit doses were labeled with Code 49 symbology; each label measured 0.8 x 1.25 inches. Each patient cassette was labeled using Code 39 symbology. A cost-benefit model was developed, and the two dispensing systems were compared with respect to (1) time to fill patient cassettes, (2) time to verify patient cassettes, (3) time to process patient charges and credits, (4) time to correct dispensing errors, (5) accuracy of the cassette-filling process, and (6) accuracy of the cassette verification process. Bar-code dispensing and verification saved 1.52 seconds per dose. Additionally, the cassette verification function was shifted from pharmacists to technicians. Estimated per-dose cost of the bar-code system was 2.73 cents. A measurable improvement in the accuracy of filling patient cassettes was documented. The feasibility of using bar codes in unit dose dispensing was demonstrated, and the prototype system was shown to produce cost efficiencies and patient-care benefits.

Congenital anemia, dyskeratosis, and progressive alopecia in Polled Hereford calves

A new syndrome of anemia, alopecia, and dyskeratosis was identified in Polled Hereford calves in this study. Cutaneous changes included hyperkeratosis and hair loss around the muzzle and ear margins, which progressed to a generalized alopecia and hyperkeratotic dermatitis. Histologically, orthokeratotic hyperkeratosis with dyskeratosis of epidermal and follicular keratinocytes was present. Alopecia was correlated with dyskeratosis of Huxley's layer and an increasing proportion of follicles in the telogen phase of the hair cycle. Dermatitis was characterized by a mild dermal mononuclear cell infiltrate and mild lymphocytic perivascular dermatitis. The anemia present at birth was nonprogressive and was classified as normochromic and normocytic to macrocytic. Reticulocytosis was absent, but bone marrow was markedly hyperplastic. Nuclear cytoplasmic asynchrony of the rubricyte and metarubricyte stages occurred in the bone marrow. Abnormal rubricyte nuclei and maturation arrest at the late rubricyte stage were common. Cytologic features of the erythroid series are similar to those of type I congenital dyserythropoietic anemia of human beings. Genealogic features suggest that this is a primary hereditary defect. The mode of inheritance, however, remains to be determined.

Rorschach assessment of purging and nonpurging bulimics

Research in bulimia has flourished in recent years, and yet minimal attention has been devoted to explorations of the bulimic's basic personality organization. We utilized the Rorschach to differentiate between purging and nonpurging bulimics and controls. There were 15 subjects in each group. The Comprehensive System (Exner, 1986) was used for the scoring of the protocols. Statistically significant differences were not found between the two bulimia groups, but interesting trends were detected in the areas of depression, anger, and self-preoccupation. Results appear to be constrained by the low rate of purging behavior. Comparisons between the combined bulimia groups and the controls resulted in solidly characterizing the bulimics as displaying perceptual inaccuracies, disordered thinking, a vulnerability to interpersonal problems, a damaged self-image, and a pessimistic outlook. The strengths of the study were its use of the Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev. [DSM-III-R]; American Psychiatric Association, 1987) nonpatients bulimic subtypes and a control group that was comparable in terms of demographics. Future Rorschach studies with bulimics displaying higher frequencies of binging and purging behaviors are suggested.

HIV risk behavior reduction following intervention with key opinion leaders of population: an experimental analysis

BACKGROUND AND PURPOSE

Peer norms influence the adoption of behavior changes to reduce risk for HIV (human immunodeficiency virus) infection. By experimentally intervening at a community level to modify risk behavior norms, it may be possible to promote generalized reductions in HIV risk practices within a population.

METHODS

We trained persons reliably identified as popular opinion leaders among gay men in a small city to serve as behavior change endorsers to their peers. The opinion leaders acquired social skills for making these endorsements and complied in talking frequently with friends and acquaintances. Before and after intervention, we conducted surveys of men patronizing gay clubs in the intervention city and in two matched comparison cities.

RESULTS

In the intervention city, the proportion of men who engaged in any unprotected anal intercourse in a two-month period decreased from 36.9 percent to 27.5 percent (-25 percent from baseline), with a reduction from 27.1 percent to 19.0 percent (-30 percent from baseline) for unprotected receptive anal intercourse. Relative to baseline levels, there was a 16 percent increase in condom use during anal intercourse and an 18 percent decrease in the proportion of men with more than one sexual partner. Little or no change was observed among men in the comparison cities over the same period of time.

CONCLUSIONS

Interventions that employ peer leaders to endorse change may produce or accelerate population behavior changes to lessen risk for HIV infection.

HIV risk behavior reduction following intervention with key opinion leaders of population: an experimental analysis

BACKGROUND AND PURPOSE

Peer norms influence the adoption of behavior changes to reduce risk for HIV (human immunodeficiency virus) infection. By experimentally intervening at a community level to modify risk behavior norms, it may be possible to promote generalized reductions in HIV risk practices within a population.

METHODS

We trained persons reliably identified as popular opinion leaders among gay men in a small city to serve as behavior change endorsers to their peers. The opinion leaders acquired social skills for making these endorsements and complied in talking frequently with friends and acquaintances. Before and after intervention, we conducted surveys of men patronizing gay clubs in the intervention city and in two matched comparison cities.

RESULTS

In the intervention city, the proportion of men who engaged in any unprotected anal intercourse in a two-month period decreased from 36.9 percent to 27.5 percent (-25 percent from baseline), with a reduction from 27.1 percent to 19.0 percent (-30 percent from baseline) for unprotected receptive anal intercourse. Relative to baseline levels, there was a 16 percent increase in condom use during anal intercourse and an 18 percent decrease in the proportion of men with more than one sexual partner. Little or no change was observed among men in the comparison cities over the same period of time.

CONCLUSIONS

Interventions that employ peer leaders to endorse change may produce or accelerate population behavior changes to lessen risk for HIV infection.

Transovarial transmission

The success of a parasite depends upon its ability to transmit itself to new hosts. Many parasites are passed on from mother to daughter in a process known as vertical, or linear, transmission. Vertical transmission includes parasites transmitted across the placenta or via milk but in this review Judy Smith and Alison Dunn concentrate specifically on intracellular parasites. Transovarial transmission is widely used by a range of organisms but its importance, particularly in transmission of parasites, has rarely been studied.

In vitro and in vivo glucose consumption in swine eperythrozoonosis

One complication of swine eperythrozoonosis is the hypoglycemia that occurs during parasitemia. To determine the cause of the hypoglycemia, we studied glucose consumption in splenectomized pigs infected with Eperythrozoon suis. With the rapid rise of erythroparasites, the in vitro glucose consumption of parasited whole blood increased dramatically, and hypoglycemia developed. Because mature porcine erythrocytes are impermeable to glucose, the increased glucose consumption is most logically the result of E. suis metabolism. Iodoacetamide and sodium fluoride (which inhibit glycolysis), but not sodium cyanide (which prevents cellular respiration), and tetracycline (which is used to treat eperythrozoonosis) inhibited glucose consumption. In vivo glucose turnover studies before infection and during peak parasitemia indicated an increased glucose production by infected pigs during parasitemia. The results suggest that hypoglycemia occurs during swine eperythrozoonosis because the parasite uses glucose faster than the gluconeogenic pathways can provide it.