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Biomedical subjects

T Ross

Publications and source records attributed to T Ross.

At least 73 records · Page 4Linked to original sources
PubMed1996

Shelf life prediction: status and future possibilities.

Although there is rapid progress in the field of chemical detection technology, little of this technology appears to have found application in estimation of the remaining shelf life of foods and early detection of spoilage. Predictive microbiology aims to summarise the probable behaviour of specific spoilage organisms and the progression of spoilage processes in foods. The quantitative knowledge generated in the field of predictive microbiology provides a sound basis for the rational development of devices with which to monitor loss of product shelf life during storage, distribution and retail sale. To predict remaining shelf life accurately it is necessary, however, to consider the microbial ecology of the food system. Aspects of microbial ecology and physiology relevant to the spoilage of foods are briefly reviewed and the potential benefits of the use of predictive microbiology in shelf life estimation are described. These points are exemplified by reference to a modelling program undertaken to develop, validate and 'package' in an easily useable from, models of the effect of temperature, water activity and pH on the growth rate of psychrotrophic spoilage pseudomonads. Necessary properties of devices to monitor loss of shelf life are discussed. 'Bioindicators' are identified as potential monitors of spoilage and suggestions made for their development based on the concept of 'upper limiting bacterial growth' rates, for which preliminary evidence is presented.

Food Microbiology↗
PubMed1996

Indices for performance evaluation of predictive models in food microbiology.

Two complementary measures are proposed as simple indices of the performance of models in predictive food microbiology. The indices assess the level of confidence one can have in the predictions of the model and whether the model displays any bias which could lead to 'fail-dangerous' predictions. The use of the indices is demonstrated using data collated from independent and published literature. This analysis supports previous reports that evaluation of predictive models by comparison to published microbial growth rate data may be inappropriate because of limitations in that data. The indices may fail to reveal some forms of systematic deviation between observed and predicted behaviour. It is concluded, however, that the indices provide an objective and readily interpreted summary of model performance and may serve as a first step towards the development of an objective and useful definition of the term 'validated model' in predictive food microbiology.

Evaluation Studies as Topic↗
PubMed1996

Colonic carcinoma presenting as an appendiceal abscess in a young woman.

A 38-year-old woman with stage T4N0M0 adenocarcinoma of the cecum presented with what seemed to be an appendiceal abscess. She had a 10-month history of intermittent abdominal pain in the right lower quadrant. Initial laparotomy revealed an abscess in that quadrant. The abscess was drained. A mass in the cecum, associated with dense fibrous tissue and abscess formation, was found on subsequent surgical exploration. Pathological examination revealed a well-differentiated mucinous adenocarcinoma of the cecum with transmural invasion. The lesion had replaced most of the vermiform appendix and was associated with a periappendiceal abscess. Colonic carcinoma masquerading as acute appendicitis or an appendiceal abscess is a well-recognized entity in the elderly but may be overlooked in younger patients because malignant disease is not suspected.

Abscess↗
PubMed1995

The relationship between depression and cognition in older adults: a cross-validation study.

The relationship between depression and cognition in older adults has become a topic of extensive research and clinical interest. Results of previous research are limited, however, by sampling and methodological problems. Small sample sizes and the treatment of depression as a dichotomous variable may be major factors that limit data interpretation in previous studies. The present sample of 220 geriatric medical patients was split into a validation and a cross-validation sample specifically to test the hypothesis that depression is an independent predictor of cognition. Multiple regression analyses, controlling for the direct effects of demographic factors, found that Geriatric Depression Scale scores were consistently a significant predictor of Dementia Rating Scale and Logical Memory scores. Overall, GDS scores accounted for approximately 8% of unique variance for both measures of cognition. Demographic factors, particularly age and race, were also significant predictors of cognitive test scores. These data were interpreted as providing support for the hypothesis that level of depression predicts level of cognitive functioning.

Aged↗
PubMed1995

Bone mineral density in children with mild osteogenesis imperfecta.

We used dual-energy X-ray absorptiometry (DEXA) to compare the bone mineral density (BMD) of nine children aged from 2 years 7 months to 13 years 5 months who had mild osteogenesis imperfecta with an age- and sex-matched control group. The patients had only mild clinical symptoms but DEXA detected highly significant differences in BMD between them and the controls. The mean BMD in the children with osteogenesis imperfecta was 76.7% of normal in the lumbar spine (p < 0.001) and 71.2% of normal in the femoral neck (p < 0.001). DEXA is an objective, reproducible and sensitive method of measurement of BMD in children. It may help to establish the diagnosis, to assess prognosis and possibly to monitor the response to different types of treatment.

Absorptiometry, Photon↗
PubMed1994

Predictive microbiology.

Predictive microbiology is based upon the premise that the responses of populations of microorganisms to environmental factors are reproducible, and that by considering environments in terms of identifiable dominating constraints it is possible, from past observations, to predict the responses of those microorganisms. Proponents claim that predictive microbiology offers many benefits to the practice of food microbiology, and there is growing interest internationally. This review considers the origins, benefits and approaches to predictive microbiology and critically considers limitations and potential solutions. It is suggested that the traditional delineation between kinetic and probabilistic models is artificial, and that the two approaches represent the opposite ends of a spectrum of modelling needs. It is concluded: that despite the complexity of many food systems predictive modelling can be successfully applied; that strategies based on predictive models can simplify problems and allow useful predictions and analyses to be made; that the full potential of the technique has not yet been realised; and that "predictive microbiology" may be seen as providing a rational framework for understanding the microbial ecology of food.

Bacteria↗
PubMed1994

Estimation of bacterial growth rates from turbidimetric and viable count data.

The relationship between maximum specific growth rates (mu max) determined from viable counts and turbidimetric measurements for a range of bacterial species is examined in order to assess the potential of turbidimetric methods in predictive microbiology. Two methods for the estimation of mu max from turbidimetric data are presented. One is based on absorbance and the other on transmittance measurements. Both are compared to estimates obtained by viable count methods. Calibration factors, a function to correct the non-linearity of absorbance measurements, and variance stabilising transformations for corrected absorbance measurements and for viable count data, are determined. It is concluded that turbidimetric measurements may be used reliably for estimation of mu max.

Bacteria↗
PubMed1994

Facial recognition in hypothetically schizotypic college students. The role of generalized poor performance.

This study investigated facial and facial affect recognition abilities among hypothetically schizotypic college men, defined by high scores on the perceptual aberration, magical ideation, and schizotypy scales. Groups were commensurate in age, handedness, and general intelligence. Multiple analyses of variance revealed that high-scoring subjects, relative to control subjects, made more errors on a facial affect recognition task (F = 5.32, p < .05) and on a facial recognition task (F = 8.5, p < .01). Additional multiple analyses of covariance using the face recognition scores as the covariant found no group differences. These results extend similar findings in schizophrenic individuals to hypothetically schizotypic college students, and suggest that both groups exhibit affect recognition deficits that reflect generalized attention and vigilance deficits rather than a specific emotion recognition deficit.

Adult↗
PubMed1993

An unusual intraoperative complication of stapled colorectal anastomosis: report of a case and review of the literature.

The unusual intraoperative complication of inadvertent formation of a stapled colovaginal anastomosis is described in a 61-year-old woman with diverticular disease. Intraoperative complications of linear staplers, linear cutters and circular end-to-end anastomotic staplers are reviewed, as are methods of prevention and management of such complications. The discussion focuses mainly on the complications that may arise in low anterior resection. They are more likely due to operator error than to instrument failure.

Acute Disease↗
PubMed1991

Imprisonment and tuberculosis in HIV-infected women.

The incidence of concomitant infections of tuberculosis (TB) and HIV in the same subject is on the increase, especially among inmates of jails and correctional institutions. The investigator examined the medical records of a sample of HIV-positive women prisoners for the presence of TB, and compared them to a sample of HIV-positive women who were not prisoners. Tuberculosis was found to be related to HIV-positive women prisoners (X2 (1, N = 56) = 4.62, p less than .04). The nosocomial spread of TB among HIV-positive women prisoners has an exponential potential for increase, not only to other prisoners, but to caretakers and to the overwhelmed communities to which they are released. Their infants and children are at risk for both infections. Nurses who work with HIV-positive patients, especially those with a recent prison history, drug addiction, or homelessness are at increased risk for contracting tuberculosis from their patients, often of the drug-resistant type.

Female↗
PubMed1988

Rectovaginal fistula: initial experience.

Rectovaginal fistulas are not common, but the associated symptoms can be emotionally and physically disabling. The authors report their experience of 10 patients with a diagnosis of rectovaginal fistula, seen between December 1982 and July 1986. The women ranged in age from 28 to 74 years. All complained of passing feces or flatus, or both, through the vagina. In the majority of cases, fistulas were present for longer than 6 months before surgical repair. The fistulas were due mainly to trauma. Endorectal advancement flaps were used in seven patients with excellent results. Small fistulas due to obstetric trauma may heal spontaneously, so in these cases a 6-month waiting period before operation is recommended. However, fistulas due to inflammatory bowel disease will not heal spontaneously and should be repaired as soon as the patient's condition is optimal.

Adult↗
PubMed1987

Ambulatory procedures in anorectal surgery.

In view of the broad spectrum of conventional and unconventional STDs in the homosexual man, the following diagnostic workup is recommended: History. Physical examination, including proctosigmoidoscopy with biopsy. Urethral, pharyngeal, and rectal cultures. Darkfield examination of any genital ulceration. Stool cultures for bacteria and parasites. Serologic analysis, including VDRL and, where indicated, for Chlamydia trachomatis and amebiasis. It is an essential part of proctologic practice for the surgeon to be able to recognize, diagnose, and treat sexually transmitted diseases.

Ambulatory Surgical Procedures↗
PubMed1987

Surgical treatment of anal incontinence.

The records of 18 consecutive patients operated upon for fecal incontinence between January 1983 and March 1986 were reviewed. Anterior sphincteroplasty was performed on 11 patients with direct sphincter trauma. The results were excellent in eight, fair in two and poor in one. A postanal repair was performed on seven patients, with excellent results only in two, fair in four and poor in one. The indications for surgery and the results were assessed clinically and manometrically. A careful classification of the physiologic and anatomic derangements of the anal sphincter aids in the appropriate selection of candidates for surgical treatment. In general, anterior sphincteroplasty gives good results, whereas results of postanal repairs are less satisfactory. Manometry is of some use in providing objective measurements.

Adolescent↗
PubMed1986

Effects of nutritional environment and ram effect on breeding season in range sheep.

Effects of season, nutritional environment, and presence of rams on incidence and rate of ovulation in fine-wool sheep in southern New Mexico were investigated over 14 months (February 1983-March 1984). Number of corpora lutea (CL) were observed each month by laparoscopy in random samples from six ewes in each subgroup. Seasonality of ovulation in fine-wool sheep managed on range was much more marked than in animals managed on alfalfa hay in drylot. Incidence of ovulation approached zero in range-managed ewes during May, June, and July (8%, 0%, 4%) but was higher (P<0.05) in the alfalfa-drylot group (42%, 17%, 75%), respectively. Although the incidence remained lower (P<0.05) in August in range-managed than in drylot ewes (50% and 83%, respectively), both groups were ovulating at a high rate during September through January. Incidence of ovulation dropped dramatically both years in the range-managed group in February compared with that of the alfalfa-drylot group (48% and 36% vs 100% and 83%). Mean ovulation rate per ewe ovulating did not differ (P>0.10) between nutrition groups within the 14 months. Body weight was related to CL number during periods of seasonal transition only. Continuous or intermittent presence of a ram had no real effect on either incidence or rate of ovulation during the transitional months. Nutritional environment can affect seasonality of breeding in fine-wool range sheep. This effect may not be consistently modified by presence of rams.

Journal Article↗