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Biomedical subjects

M Jenkins

Publications and source records attributed to M Jenkins.

At least 19 recordsLinked to original sources
PubMed1992

Adenoid cystic carcinoma of the breast.

Adenoid cystic carcinoma of the breast is a rare neoplasm, with only 140 cases having been reported to date. Data on 123 of these cases are reviewed herein and another case is presented in detail. Several features distinguish this type of breast cancer from more typical histologic types and suggest that it may have a unique tumor behavior. The prognosis appears to be favorable and the incidence of axillary lymph node involvement is lower. Distant metastases are uncommon, but they tend to occur without prior lymph node involvement. This lack of prognostic significance for negative axillary lymph nodes underscores the need for other prognostic markers in this disease and suggests that axillary dissection can be eliminated in most cases. Similarities to typical breast cancer include the incidence of local recurrence and the lack of effect of surgical treatment on distant metastases and overall survival. These data suggest that breast-conserving treatment may be applicable to adenoid cystic carcinoma.

Breast Neoplasms↗
PubMed1992

Expressed emotion in depressed patients and their partners.

This study was designed to assess the expressed emotion (EE) status in the spouses of depressed patients and the patients themselves, to relate the EE status to the severity of depression as measured by the Beck Depression Inventory (BDI), and to compare the prevalence of high EE between the target and control group. Seventeen depressed patients and their spouses, and 20 control couples participated in the study. The Five-Minute Speech Sample was used to assess the EE status. High EE was significantly more common in spouses of depressed patients and the patients themselves than in controls. There was a significant relationship between the EE status of the patients and their spouses. High EE in the patient and in the spouse corresponded significantly with a high BDI score of the patient. These findings underline the importance that in EE research the patients' EE status as well as their present mental health state must also be taken into account.

Adult↗
PubMed1992

New aspects of neonatal herpes.

Herpes simplex virus (HSV) is a rare but increasingly prevalent agent of newborn infection. Primary or first episode genital infection in the mother constitutes the greatest risk of infection in the neonate. Transplacental, HSV-specific functional antibody appears to protect infants from severe disease and may be therapeutically exploitable. Prevention of serious sequelae in the infant depends on early diagnosis and treatment of HSV-infected infants.

Antiviral Agents↗
PubMed1991

The majority of CD4+8- thymocytes are functionally immature.

The thymus is the major site of T cell development and repertoire selection. During these processes, T cells segregate into two subsets that express either CD4 or CD8 accessory molecules, the phenotype of peripheral T cells. Analysis of CD4+8- thymocytes revealed that the majority of these cells express the heat-stable Ag (HSA) but not the nonclassical class I Ag, Qa-2. This HSA+, Qa-2- phenotype is similar to that of the less mature, CD4+8+ thymocytes. The remaining CD4+8- thymocytes possess the HSA-, Qa-2+ phenotype of peripheral T cells. To determine whether the Qa-2-, CD4+8- thymic subset is fully mature, we have analyzed the functional status of these CD4+8- subpopulations. The results indicate that only those thymocytes which express Qa-2 are fully responsive to anti-TCR stimulation in a manner analogous to peripheral T cells. The Qa-2- subset is nonresponsive to stimulation by anti-TCR antibodies that have been immobilized to plastic, even in the presence of lymphokines or syngeneic APC. This subset is, however, capable of proliferating to allogeneic cells or to anti-TCR on the surface of syngeneic APC, although not to the levels achieved by Qa-2+ thymocytes. Thus, the Qa-2- subset appears to require additional interactions which are not necessary for peripheral T cells or Qa-2+ thymocytes. Relevant to this issue, the Qa-2+ thymocyte subset does not appear until relatively late in development, and does not reach adult frequencies until several weeks after birth. These results would suggest that there is a progression from HSA+, Qa-2- to HSA-, Qa-2+ which parallels the maturation of functional responsiveness. These findings are important to understanding T cell selection since thymocytes with such a decreased responsiveness may have a differential capacity for tolerance induction. The results presented suggest that the bulk of CD4+8- thymocytes are not fully mature and that Qa-2 may serve as a marker for T cells with a more complete functional competence.

Animals↗
PubMed1991

Childhood melanoma.

In melanoma patients, the prognostic value of tumor depth, Clark's level, the presence of ulceration, and regional involvement have not been clearly documented in the pediatric population. This report correlates these factors in a population-based study of patients under the age of 20 years. Of the initial 35 melanoma patients registered in southern Alberta with the Alberta Cancer Board, 14 were found on review to have a diagnosis other than melanoma. In the remaining 21 cases the diagnosis of melanoma was confirmed. There was a suggestion that patients with deeper lesions had a worse prognosis, but this was statistically confirmed only using Clark's levels. The children were then compared with all melanoma patients diagnosed in southern Alberta over the same time period. There was no difference in tumor depth, Clark's level, ulceration, regional involvement, or survival between these two groups. The natural history in children appears to be similar to that of the adult population, contrary to previous reports suggesting a markedly worse prognosis.

Adolescent↗
PubMed1991

Cystic fibrosis: scoring system with thin-section CT.

The progression of lung disease in patients with cystic fibrosis (CF) was evaluated with chest radiography. The severity and extent of the various radiographic changes were scored with the Chrispin or the Birmingham method, which involves the use of imprecise and subjective terms, such as line shadows, large pulmonary shadows, and nodular cystic lesions. Although computed tomography (CT) has been shown to be helpful in the evaluation of lung disease in CF, no scoring system or other objective criteria have been developed for the evaluation of the wide range of pulmonary changes in these patients. A CT scoring system was devised that incorporates all of the changes seen in the lungs of patients with CF. Such a scoring system may facilitate objective evaluation of existing and newly developed therapeutic regimens and may be a valuable tool in the preoperative evaluation of patients being considered for lobectomy or bullectomy and in the selection of patients for lung transplantation.

Adolescent↗
PubMed1991

Burn injuries in children.

The overall outcome for every patient is to attain the maximum level of physical and psychosocial functioning possible within their capacity. This is individualized and impacted by the severity of injury, interventions, and subsequent outcomes along the critical path to recovery. Identification of issues, whether physical or psychosocial, in a timely manner and the development of an individualized plan of care maximize the quality of care each patient receives. As the health care giver in most frequent contact with the patient and family, the nurse must serve as the coordinator of all ancillary services and the plan of care.

Adolescent↗
PubMed1990

Effects of graded dietary levels of Spirulina maxima on vitamins A and E in male rats.

The effects of ingesting the alga Spirulina maxima on the storage and utilization of vitamins A and E were investigated by feeding diets containing 0, 2.7, 10.7, 18.7 and 26.7% S. maxima to male rats for 6 wk. All diets contained 18% protein, which was contributed by S. maxima or by casein or by a mixture of them. Growth results indicated that rats did not utilize the diets containing S. maxima as well as the casein control diet (0% S. maxima) when levels were 10.7% or more of the diet. The ingestion of S. maxima caused a significant increase in dry matter and chloroform-extractable crude fat in the feces. A low level of 2.7% S. maxima caused a significant reduction in plasma, liver and heart alpha-tocopherol levels. The concentrations of alpha-tocopherol in these tissues showed a marked decline with 10.7% S. maxima in the diet, followed by a lesser decline at higher levels. Liver retinoid levels of rats increased when S. maxima was added to the diet, suggesting conversion of the naturally occurring carotenoids in S. maxima to vitamin A. However, the plasma levels of retinol decreased when S. maxima was fed at 10.7% or more. These data demonstrate that S. maxima can significantly alter the storage and utilization of vitamins A and E.

Administration, Oral↗
PubMed1990

Metabolic effects of reducing rate of glucose ingestion by single bolus versus continuous sipping.

Modifying the rate of absorption has been proposed as a therapeutic principle of specific relevance to diabetes. To demonstrate clearly the metabolic benefits that might result from reducing the rate of nutrient delivery, nine healthy volunteers took 50 g glucose in 700 ml water on two occasions: over 5-10 min (bolus) and at a constant rate over 3.5 h (sipping). Despite similar 4-h blood glucose areas, large reductions were seen in serum insulin (54 +/- 10%, P less than 0.001) and C-peptide (47 +/- 12%, P less than 0.01) areas after sipping, together with lower gastric inhibitory polypeptide and enteroglucagon levels and urinary catecholamine output. There was also prolonged suppression of plasma glucagon, growth hormone, and free-fatty acid (FFA) levels after sipping, whereas these levels rose 3-4 h after the glucose bolus. An intravenous glucose tolerance test at 4 h demonstrated a 48 +/- 10% (P less than 0.01) more rapid decline in blood glucose (Kg) after sipping than after the bolus. Furthermore, FFA and total branched-chain amino acid levels as additional markers of insulin action were lower over this period despite similar absolute levels of insulin and C-peptide. These findings indicate that prolonging the rate of glucose absorption enhances insulin economy and glucose disposal.

Administration, Oral↗
PubMed1989

Diminished antigen processing by endosomal acidification mutant antigen-presenting cells.

The role of acidified endosomes in Ag processing was investigated using mutant Chinese hamster ovary cells that express temperature sensitive defects in their acidification mechanism. These cells were transfected with MHC class II genes to convert them to APC. When such mutant cells were incubated at the nonpermissive temperature, losing early endosomal but not lysosomal acidification, their ability to process several native protein Ag was impaired. The nonpermissive temperature did not affect Ag processing by transfected wild type parental cells. Furthermore, T cells were stimulated normally under these conditions when the mutant cells presented antigenic peptide fragments, which do not require processing. The mutant cells were also not defective in the uptake and overall degradation of native antigen. The elimination of Ag processing by paraformaldehyde and chloroquine treatment of the Chinese hamster ovary cells indicates that these cells do not use a different process than physiologic APC. These results suggest that acidification of early endosomes is an important event in Ag processing.

Animals↗
PubMed1989

Nutritional and pathological changes in male and female rats fed modifications of the AIN-76A diet.

Male and female weanling Sprague-Dawley rats were fed either an AIN-76A diet or a modification of the AIN-76A diet containing no added DL-methionine but with higher levels of vitamins, fluoride and magnesium than in the AIN-76A diet. Both diets were fed, to groups of ten rats of each sex, at 18% protein or a reduced protein level of 13% for 12 wk. Within each sex, all diets produced comparable weight gains in rats at the end of 12 wk, except that the reduced-protein modified AIN-76A diet was associated with a reduction in weight gain in male rats. Both diet and protein level had statistically significant effects on the relative weights of some organs, particularly the kidney. The AIN-76A and the reduced-protein AIN-76A diets significantly increased the relative kidney weights (% body weights) of female rats, when compared with the effects of both modified AIN-76A diets (18 and 13% protein). Male rats fed both of the diets containing 18% protein had higher relative kidney weights than did those consuming both 13% protein diets. Females fed the modified diet containing 13% protein had significantly lower liver weights than the other groups. In both sexes, the two diets containing 18% protein caused significantly higher plasma urea nitrogen concentrations than did the lower protein diets. Kidney calcium concentrations varied with the diet, with dietary protein level, and with the sex of the animal. All diets caused small mineral (calcific) concretions of minimal to mild severity in the lumina of scattered renal tubules in the cortex and/or medulla of male rats. All female rats fed the AIN-76A and the reduced-protein AIN-76A diet had large, moderate or severe mineral concretions in the tubules at the corticomedullary junction and this was associated with increased renal calcium levels. The higher concentration of renal calcium at the lower dietary protein level (13%) was associated with severe corticomedullary junction mineralization. The higher protein diets were associated with an increased incidence of hyaline droplets in the cytoplasm of kidney cortical tubules in male rats.

Animal Feed↗
PubMed1989

Natural history of in situ breast cancer in a defined population.

The entire experience of in situ breast cancer in Alberta from 1953 to 1984 was examined. Of 243 patients coded, 226 were available for review by a panel of three pathologists. In 149 cases the diagnosis of in situ disease was confirmed. One hundred and eight patients had 109 ductal carcinomas in situ, 38 patients had lobular carcinomas in situ, with 3 patients having both. A multitude of treatments was used, ranging from local excision to radical mastectomy. Survival at a mean of 6 years follow-up was equal in all groups, with only two patients with a confirmed diagnosis of ductal carcinoma in situ dying from clinically suspected systemic disease. In patients treated by local excision, ipsilateral cancers were seen in 12% of ductal carcinoma in situ patients who had local excision and 13% of patients with lobular carcinoma in situ. Contralateral metachronous invasive cancers were seen in 6% of ductal carcinoma in situ patients and 3% of lobular carcinoma in situ patients. No lymph node involvement was seen in any of these patients, either with prophylactic dissection or in follow-up. The conclusion reached was that both in situ lesions are similar in their clinical course. Lymph node dissection is not necessary. Pathologic review is critical for accurate studies, with a change in diagnosis of 36% of diagnoses. Treatment does not appear to affect prognosis. The most appropriate treatment needs to be determined in prospective randomized trials.

Adult↗
PubMed1989

Photobiological properties of a novel, naturally occurring furoisocoumarin, coriandrin.

The photobiological properties of a novel, naturally occurring furoisocoumarin isolated from coriander and named coriandrin are described. Photosensitized lethal and mutagenic effects in bacteria indicate that it is more active than psoralen. It is a weak frameshift mutagen in the dark. Mammalian cells in tissue culture are photosensitized more actively with coriandrin than with psoralen even though preliminary evidence from interrupted radiation experiments and DNA analysis suggest that coriandrin does not form DNA interstrand crosslinks. Sister chromatid exchanges were induced with a unit dose of 1.1 x 10(-2) with coriandrin; the value for psoralen is 3 x 10(-3). Coriandrin appears to be metabolized more rapidly than furocoumarins by liver mixed function oxidases. Skin photosensitizing activity is very weak compared with psoralen, a surprising observation considering its potency in biological test systems.

Animals↗