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Biomedical subjects

J E Jones

Publications and source records attributed to J E Jones.

At least 19 recordsLinked to original sources
PubMed1992

Transoral surgical management of lesions of the base of the tongue.

Lesions of the base of the tongue are rare in the pediatric population. However, when present these lesions may lead to airway obstruction and feeding difficulties. Two patients with lesions of the base of the tongue are described to demonstrate the diagnosis and management of this difficult clinical problem. The use of a transoral median glossotomy for total excision of these lesions is advised in this article. This approach affords excellent surgical exposure, early return to a normal diet, and lack of facial scars.

Airway Obstruction↗
PubMed1992

The effect of inoculation of Pasteurella haemolytica into the lactating mammary gland of mice, rats, rabbits, sows and cows.

An isolate of Pasteurella haemolytica (A9), which consistently produced severe mastitis in ewes, was inoculated into the lactating mammary glands of a variety of species. Mastitis did not develop after the inoculation of log-phase bacteria into the mammary gland of lactating mice, rats, rabbits or sows but did so in the mammary gland of two cows. Another A9 isolate from a ewe with mastitis and an A1 isolate from a bovine pneumonic lung also induced mastitis in cows. Thus, in this study, P. haemolytica produced mastitis only in ruminant animals.

Animals↗
PubMed1992

The effect of the intra-mammary inoculation of lactating ewes with Pasteurella haemolytica isolates from different sources.

Lactating Welsh Mountain ewes were inoculated, 3 weeks after lambing, with between 1000 and 10,000 colony forming units of a number of isolates of Pasteurella haemolytica. Isolates from severe, acute mastitis in a ewe, from ovine and bovine pneumonic lesions and from the nasal cavity of healthy lambs, all gave rise to severe, acute mastitis that was clinically indistinguishable from that seen naturally. Two isolates from the milk of ewes with subclinical mastitis did not cause clinical disease after inoculation and, in most ewes, were immediately eliminated. These results suggest that a variety of strains of P. haemolytica are capable of causing severe mastitis in sheep, regardless of their origin, and that there are strains of lower pathogenicity for the mammary gland which are not capable of causing clinical mastitis.

Animals↗
PubMed1992

Ovarian masses revisited: radiologic and pathologic correlation.

Diagnosis of ovarian masses can be difficult because many pathologic conditions can affect the ovary and have similar clinical and radiologic manifestations. Knowledge of pathologic, age-specific characteristics can help refine the differential diagnosis. Ovarian masses are nonneoplastic (ovarian functional cysts, polycystic ovary disease, and ovarian torsion) or neoplastic (surface epithelial, sex cord-stromal, germ cell, and metastatic tumors). Functional cysts, if complicated by hemorrhage, can have a confusing ultrasonographic (US) appearance. Polycystic disease and torsion are easily diagnosed with US. Benign and malignant forms of serous and mucinous surface epithelial tumors can usually be differentiated with US. Imaging features of surface epithelial tumors of low malignant potential are nonspecific, resembling those of benign serous and mucinous tumors. Mature (benign) teratomas are usually cystic, with components of fat, soft tissue, and calcium, and are sonographically distinct from immature (malignant) teratomas, which are mostly solid. Sex cord-stromal tumors occur more often in menopausal or postmenopausal women and are typically solid. Metastatic disease is less common than other ovarian tumors; however, its radiologic appearance may resemble those of other masses.

Adult↗
PubMed1992

Severity of premenstrual symptoms in relation to medical/psychiatric problems and life experiences.

The Premenstrual Experience Assessment, a comprehensive questionnaire, was completed by 878 women who were currently having menstrual cycles. Their severity of premenstrual symptoms was studied in relation to demographic variables, gynecological problems, use of medications, psychiatric experience, life stressors, and duration of severity. 14 significant relationships were found. The findings are discussed both in terms of research and clinical practice.

Adaptation, Psychological↗
PubMed1992

The pharmacokinetics of intraperitoneal erythropoietin administered undiluted or diluted in dialysate.

OBJECTIVE: To compare the bioavailability of intraperitoneal erythropoietin (EPO) administered undiluted versus diluted in 2 L of dialysis fluid. DESIGN: Group 1 patients received one dose of EPO, 400 U/kg BW given with vehicle only. This dwelled for 8 hours after which 2 L of dialysate were infused. Group 2 patients received the same dose of EPO diluted in 2 L of dialysate which dwelled for 8 hours. Both groups resumed their CAPD regimen after the first 8 hours. Blood levels of EPO were measured for 24 hours in both groups. SETTING: The Home Peritoneal Dialysis Unit, Toronto Hospital, Western Division. PATIENTS: The participants were on CAPD for at least three months, free of peritonitis, and had no abnormalities of peritoneal transport. Three patients took part in both arms of the study, and there were 6 patients altogether in each group. RESULTS: When EPO was administered undiluted, there was a greater than ninefold increase in bioavailability of the hormone as measured by the area under the curve (AUC), compared to when the same dose was diluted in 2 L of dialysis fluid. CONCLUSIONS: The previous studies that reported low bioavailability of intraperitoneal EPO used the hormone diluted in dialysate. The current findings suggest that if EPO is given in the dry peritoneal cavity, the bioavailability is greatly improved and may be clinically effective. Intraperitoneal instillation may prove to be an alternative route for EPO in the peritoneal dialysis patient unable or unwilling to receive subcutaneous injections. We are currently studying the effectiveness of undiluted intraperitoneal EPO in CAPD patients.

Adult↗
PubMed1992

Jaundice.

Jaundice is a disorder of bilirubin metabolism and has many causes. History and physical examination help establish the diagnosis in 70 to 80 percent of patients. Elevation of alkaline phosphatase and gamma-glutamyl transpeptidase suggests cholestasis, either intrahepatic (e.g., medication reactions) or extrahepatic (e.g., choledocholithiasis), whereas markedly elevated serum aminotransferases are indicative of hepatocellular damage from infection, toxins or ischemia. Ultrasound examination is a useful initial procedure when extrahepatic obstruction is suspected. Endoscopic retrograde cholangiopancreatography and computed tomography may be better used to diagnose obstruction at the level of the pancreas or distal common bile duct. The treatment is based on the etiology of jaundice and includes removal of offending medications or toxins, therapy for underlying liver disease or surgery for extrahepatic obstruction.

Female↗
PubMed1991

Autoantibody production in hepatitis B e antigen transgenic mice elicited with a self T-cell peptide and inhibited with nonself peptides.

Studies in hepatitis B e antigen (HBeAg)-expressing transgenic mice indicate that self tolerance to two T-cell determinants on the same transgenic self molecule can differ markedly. The dominant T-cell site on HBeAg is tolerogenic, whereas a proportion of T cells recognizing a second T-cell site evade tolerance induction, persist in the periphery, and can be activated in vivo by a single injection of a 12-residue T-cell self peptide. The self-reactive T cells mediate in vivo autoantibody production sufficient to neutralize detection of the autoantigen in serum. Furthermore, autoantibody production can be inhibited by nonself peptides that compete with the self peptide for binding to major histocompatibility complex molecules. This model illustrates that T cells specific for an immunogenic T-cell site on a nonsequestered autoantigen can escape tolerance induction and, more importantly, can mediate autoreactivity in vivo. Furthermore, these results suggest that synthetic T-cell sites may be useful as immunotherapeutic agents for the purpose of circumventing nonresponse to HBeAg during persistent hepatitis B virus infection.

Amino Acid Sequence↗
PubMed1991

Hair cell regeneration: the identities of progenitor cells, potential triggers and instructive cues.

Hair cells are produced and accumulate in the ears of fish and amphibians as they grow during postembryonic life; hair cell regeneration occurs in lateral line organs in those groups and in the cochlea in birds. Continuous time-lapse microscopy has directly demonstrated that supporting cells divide to give rise to hair cells during regeneration in lateral line neuromasts. Supporting cells also appear to give rise to hair cells during regeneration in the avian ear, but additional cell types have been proposed as hair cell progenitors. Alternative interpretations of current evidence are discussed in relation to the possibility that supporting cells may be the common progenitor in all cases of hair cell regeneration. The regenerative proliferation of hair cells in birds occurs in populations of cells that are mitotically quiescent in undamaged ears. Evidence suggests that the extrusion of damaged hair cells and the breaking of intercellular junctional adhesions may be a trigger for regenerative proliferation. The potential triggering influence of phagocytes is also discussed. The differentiation of replacement cells during regeneration in the cochlea may be regulated by surface interactions between cells. A model that could account for the reconstitution of the mosaic pattern of hair cells and supporting cells is proposed.

Animals↗
PubMed1991

The experimental production of mastitis in sheep by intramammary inoculation of Pasteurella haemolytica.

Acute mastitis was consistently produced in primiparous ewes by inoculation of the mammary gland, via the teat canal, with an isolate of Pasteurella haemolytica, serotype A9, originating from a field case of ovine mastitis. Mastitis developed following the inoculation of as few as 10 colony forming units of this isolate, suggesting that only a small number of organisms would be required to initiate the disease under natural conditions provided they were already beyond the teat canal. Clinical signs and macroscopic lesions were well developed within 24 h of inoculation and were similar to those found in the naturally-occurring disease. The ability to reproduce mastitis consistently will facilitate studies of the pathogenesis of the disease and the comparison of different isolates of P. haemolytica with respect to virulence determinants.

Acute Disease↗
PubMed1991

Fatal occupational electrical injuries in Virginia.

Work-related electrical injuries and fatalities in Virginia were reviewed for the period 1977 to 1985. Of 196 workers electrocuted (0.9/100,000/year), 65% (127) died between May and September. Death rates were highest for male workers in utility companies (10.0/100,000), mining (5.9/100,000), and construction industries (3.9/100,000), but these high risk groups accounted for only 50% of the deaths. Most accidental electrocutions resulted from power line contact (53%) and machine or tool usage or repair (22%). Only 1.5% (2/101) of the workers who died within 6 hours of injury and had blood alcohol concentration tested were legally intoxicated. All workers need safety education on active measures to prevent hazardous electrical exposures, not just those at high risk for electrical injury. Every work-related electrical injury represents a sentinel health event--an opportunity for preventive intervention in the workplace.

Accidents, Occupational↗
PubMed1991

Relationship between career age and research productivity for academic dentists.

The purpose of this investigation was to assess the effects of aging (career age) and research performance for full-time clinical dental faculty. The 489 respondents represented a response rate of 71.3% from a 40% stratified random sample of faculty. Respondents reported a mean number of years in full-time dental education of 10.7 (range = 1 to 45, SD = 7.7) and mean number of career publications of 11.1 (range = 0 to 110, SD = 15.2). A significant positive association of career age and life-time research productivity was observed. A significant positive association of career age and mean two-year research productivity was also noted. Implications of the findings were discussed with respect to similar studies reported for other academic disciplines.

Achievement↗
PubMed1991

Effects of exposing broiler breeders to nicarbazin contaminated feed.

Ten-mo-old broiler feeds were fed nicarbazin (NCZ) at 0, 25, 50 and 100 ppm of their diet for 2, 4, or 6 days to simulate accidental contamination of their feed with the medicant. Reduced egg production was observed in all treatments except 25 and 50 ppm NCZ for 2 days. A consistent reduction in egg weight occurred only at the maximum treatment level of 100 ppm for 6 days. Reduction in hatchability was generally evident by Days 5 and 6 of the experiment except for the lowest treatment of 25 ppm NCZ for 2 days. Due partially to the low number of eggs set, no statistically significant reduction in hatchability was seen for the group receiving 50 ppm NCZ for 4 days, but hatchability had dropped over 17 percentage points (from 93.3 to 75.5%) by Days 5 and 6 of the experiment, and continued to drop to a low of 31% on Days 11 and 12 of the experiment. Shell pigmentation was the most sensitive characteristic measured, with significant depigmentation occurring after only 2 days of feeding 25 ppm NCZ. Generally, the severity and duration of effects were in proportion to medicant concentration and length of treatment time. Fertility was not influenced by the medicant.

Animal Feed↗
PubMed1991

Signs and symptoms of parasitic diseases.

This article reviewed the parasitic signs and symptoms most likely to be seen in the office setting. Particular attention has been given to the endemic parasites. The physician will be called upon increasingly to recognize the often subtle and seemingly unrelated symptom complex. Nowhere else in the animal kingdom has the need for species survival taken a more complex and imaginative route, and it will be the primary care physician who will have first chance at the diagnosis and treatment. The long history of successful parasitic adaptations and the variety of body sites infected in man provide a challenging context for the office-based physician trying to make a clinical diagnosis.

Humans↗
PubMed1991

Giardiasis.

Giardiasis represents a major protozoan infection for the 1990s. This article reviews this organism for the primary care physician, discussing the characteristics, clinical manifestations, diagnosis, and treatment. Prevention and patient education needs are also presented.

Animals↗
PubMed1991

Parasites during pregnancy.

Parasitic infection during pregnancy is common. With most parasites, primary prevention is very effective in avoiding infestation. With the exceptions of malaria, toxoplasmosis, and African trypanosomiasis, when infection does occur, treatment decisions should be based on the impact of the infection on the patient and her fetus on an individual basis. When treatment is indicated, selection of medications with the least potential to harm the mother and more particularly the developing fetus is essential.

Female↗