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Biomedical subjects

T M Johnson

Publications and source records attributed to T M Johnson.

At least 145 records · Page 8Linked to original sources
PubMed1991

Changing trends in melanoma treatment and the expanding role of the dermatologist.

As the incidence of melanoma continues to increase, so does the role of the dermatologist as both medical and surgical oncologist for these patients, especially those with stage I disease. The dermatologist holds a key role in all phases of care, including prevention, diagnosis, treatment, and follow-up. The dermatologist is best trained to complete a full and thorough skin examination and is best able to recognize a melanoma at its earliest stages of radial growth. In large part because of advances in dermatology, the dysplastic nevus syndrome has been identified as an important marker and precursor lesion for melanoma; the dermatologist has the best knowledge base for the recognition and management of both sporadic and familial dysplastic nevi. Dermatologists also have the unique opportunity (by virtue of their patient population concerned with skin problems) to prevent melanoma through patient education concerning sun protection, self-examinations, and the ABCDs of melanoma recognition. The dermatologist is well trained to obtain an appropriate, full-thickness skin biopsy specimen and is also knowledgeable to interpret the pathologist's report, understanding the significance of the various histologic prognostic indices. Because of the changing trends in excisional margin size and fewer recommendations for ELND, the dermatologist is becoming more active in the surgical management of melanoma patients. In the MDMC, the dermatologist was clearly recognized as a capable surgeon to perform the wide local excisions for stage I patients. Almost one half of the patients seen (49%) were surgically treated in the department of dermatology. Of group I patients, 78% were treated by dermatologists. The dermatologist as surgeon should be capable of performing a wide local excision to the level of deep subcutaneous tissue or muscle fascia with an appropriate primary layered closure, local flap, or graft. Our experience confirms that the majority of patients present with local disease and a thin Breslow depth and thus can be skillfully treated in an outpatient setting under local anesthesia by a dermatologic surgeon. In follow-up, the dermatologist should provide continuity of care and should be knowledgeable in appropriate interval examinations and tests. The dermatologist is thoroughly skilled at the cutaneous examination and has the knowledge base to perform a careful and competent lymph node examination. As primary medical oncologist to these patients, the dermatologist needs to recognize stage II and stage III disease and be able to comprehensively discuss with the patient the options for treatment and how they affect their prognosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Combined Modality Therapy↗
PubMed1990

Immediate intraoperative tissue expansion.

We report a modification of the controlled tissue expansion technique, that is, immediate intraoperative tissue expansion. The procedure is performed by placing tissue expanders at the time of surgery. After placement, three to four cycles of inflation/deflation of the expander for 3 to 5 minutes are performed. In a one-stage procedure the stretched skin is then immediately used to close the surgical defect. Three case reports demonstrating the immediate intraoperative tissue expansion technique, in which the Foley catheter balloon was used as the tissue expander, are presented. These cases illustrate that this technique may allow the surgeon to cover defects more easily with less tension and with a better cosmetic result than with other closure techniques.

Adult↗
PubMed1990

Traumatic asphyxia.

Traumatic asphyxia is a distinctive clinical syndrome characterized by cervicofacial cyanosis and edema, multiple petechiae, and subconjunctival hemorrhage after a severe crush injury of the thorax or of the upper part of the abdomen. A case of traumatic asphyxia is reported, and its clinical and pathophysiologic features are discussed.

Abdominal Injuries↗
PubMed1990

Somatizing distress: hospital treatment of psychiatric co-morbidity and the limitations of biomedicine.

Analysis reveals that treatment of psychiatric co-morbidity in hospitals has a somatizing effect. The patients typically have long, costly hospital stays marked by numerous nonpsychiatric consultations. When consulted, psychiatrists are constrained by their role within the hospital social system and tend to employ somatopsychic approaches which are compatible with the orientation of their physician consultees. Case studies illustrate the inadequacy of these treatment modes and highlight the significance of social and economic problems as etiologic factors in psychiatric co-morbidity. Applying a critical approach from the field of medical anthropology, we argue that the ultimate solution to many patients' problems lies outside of the realm of biomedicine and depends on changes in social policies. Thus, the limitations of biomedicine are seen as due both to its predisposition toward somatic treatment and to larger social forces which cause its practitioners to be part of the problem rather than part of the solution.

Adolescent↗
PubMed1990

Regulation of amylase gene expression in diabetic mice is mediated by a cis-acting upstream element close to the pancreas-specific enhancer.

We localized the cis-acting sequences that mediate the regulation of a pancreatic amylase gene, Amy-2.2, in diabetic mice. We constructed three hybrid genes containing sequences from the 5'-flanking region of the amylase gene upstream of the heterologous elastase promoter linked to the CAT structural gene. These constructs were transferred to the germ line of transgenic mice by microinjection of fertilized eggs. The amylase sequences had two effects on expression of the elastase promoter: Basal expression was increased, and expression in diabetic animals was reduced to approximately 2% of basal levels. A 30-bp amylase fragment was sufficient to transfer both of these regulatory functions to the elastase promoter. Sequences within this 30-bp fragment are included in the binding site for the pancreatic nuclear protein PTF1. The close association of the PTF1-binding site and the regulatory functions is consistent with a mechanism based on interference with activation by PTF1 in diabetic pancreas. PTF1-binding activity is not reduced in diabetic pancreas. The data presented here demonstrate that the 5'-flanking region of the pancreatic amylase gene contains a novel insulin-dependent element (IDE) that mediates the loss of expression in diabetic animals.

Amylases↗
PubMed1990

Vanadate induction of pancreatic amylase mRNA in diabetic rats.

Amylase activity and mRNA abundance are reduced to less than 1% of normal levels in diabetic rat pancreas. Administration of vanadate in drinking water restored normal amylase activity and amylase mRNA levels. These results demonstrate an effect of vanadate on pancreatic acinar cells and suggest that vanadate can mimic the effect of insulin on transcription of the pancreatic amylase gene.

Amylases↗
PubMed1989

Binding of a pancreatic nuclear protein is correlated with amylase enhancer activity.

The mouse amylase gene Amy-2.2 is expressed at high levels specifically in the acinar cells of the pancreas. The region between -172 and -110 of this gene includes sequence elements common to pancreas-specific genes. Nuclear proteins with specific affinity for this region were partially purified from rat pancreas. The consensus element of another pancreas-specific gene, elastase 1, competes for protein binding to the amylase sequences. Binding was localized by DNase I protection to the sequence -156 to -122. Site-directed mutagenesis of this sequence resulted in concomitant loss of protein binding and enhancer activity. Photo-affinity labelling of pancreatic nuclear extracts identified one predominant binding protein with a molecular weight of approximately 75 kDa. The data indicate that binding of this nuclear protein is essential for the enhancer activity of this pancreas-specific element.

Amylases↗
PubMed1989

Bullous amyloidosis.

Amyloidosis may present with involvement of a variety of organ systems. Cutaneous involvement is a relatively common finding in patients with systemic amyloidosis. The occurrence of bullous skin lesions, however, is rare; only a few such cases have been previously reported. We describe a patient who presented with a subepidermal bullous skin disease initially thought to be bullous pemphigoid based on both clinical and histologic appearances. The patient subsequently developed the nephrotic syndrome. Biopsy specimens of the skin and kidney showed involvement of both organs with amyloid, and amyloid was later found in the spleen, heart, and nervous system. No subsequent evidence of myeloma was found in this patient. The clinical, histopathologic, immunofluorescent, and electron microscopic findings of systemic amyloidosis are discussed.

Amyloidosis↗
PubMed1989

Detection of circulating Aspergillus fumigatus antigen in bone marrow transplant patients.

A competitive inhibition enzyme-linked immunosorbent assay able to detect Aspergillus fumigatus antigenemia at a concentration sensitivity of 68 ng/ml was developed. To test the utility of this assay in the diagnosis of invasive aspergillosis, serum was collected twice weekly from all patients in a bone marrow transplant unit. When analyzed retrospectively, A. fumigatus antigen was detected in three of four patients (75%) with proved invasive aspergillosis at autopsy or biopsy and in a solitary patient with suspected but not proved invasive aspergillosis. No antigen was detected in 17 bone marrow transplant unit patients without proved or suspected invasive aspergillosis or in 16 healthy control subjects. Detection of antigen rose with an increasing number of samples tested. A. fumigatus antibody levels were not helpful in the diagnosis of invasive aspergillosis, although in a few patients antibody levels decreased just before death.

Antibodies, Fungal↗
PubMed1988

Multiple uses of liquepipets in Southern, northern, and western blots.

Individually wrapped, sterile disposable transfer pipets can be used in the isolation of ds-DNA and ds-RNA fragments from gels as well as in the screening of multiple samples in Southern, Northern, and Western blots without potential contamination by exogenous nucleases and proteases. The sensitivity and results obtained by this method are comparable to those obtained by conventional methods. All the prehybridization, blocking, hybridization, and detection processes can be performed within the transfer pipet. The isotopically labeled probes used in hybridization can easily be recovered, stored for reuse, or disposed of as waste with no potential contamination of personnel or laboratory equipment. Strip blots are stable in appropriate buffers within the liquepipets which can be shipped easily worldwide for comparative analyses by collaborative investigators. This method is simple, time saving, and inexpensive and is particularly suitable for multiple sample screening. Other potential applications of this procedure are discussed.

Blotting, Northern↗
PubMed1987

Absorption and metabolism of vitamin K in Swiss 3T3 mouse fibroblasts--a model system for study of vitamin K absorption and metabolism.

The vitamin K cycle previously described in liver has been demonstrated in Swiss 3T3 mouse fibroblasts. Vitamin K epoxide and gamma-carboxyglutamic acid were isolated from the cells and chemically characterized. Menaquinone (MK4) is also metabolized to its epoxide and vitamin K epoxide is reduced to vitamin K in these cells. Thus Swiss 3T3 mouse fibroblasts provide a useful model system for the study of vitamin K metabolism. Possible functions of the vitamin K-dependent protein(s) in fibroblasts are discussed.

1-Carboxyglutamic Acid↗
PubMed1987

Premenstrual syndrome as a western culture-specific disorder.

Premenstrual syndrome (PMS) has a phenomenology resembling many culture-bound (culture-specific) syndromes described in the anthropological literature. Viewed as a culture-specific syndrome, PMS is an appropriate symbolic representation of conflicting societal expectations that women be both productive and reproductive. By simultaneously denying either alternative, PMS translates role conflict into a standardized cultural idiom. Thus, despite obvious biopsychological determinants, PMS is best understood as a sociocultural phenomenon illustrating both the special status of women in Western culture and the ethnocentrism of Western anthropology which heretofore has only recently begun to identify culture-specific syndromes in its own back yard.

Achievement↗
PubMed1987

Evaluation of a perinatal grief support team.

An analysis of the effects of intervention from a perinatal grief support team was begun in 1982. Seventy-eight women experiencing stillbirth or early perinatal death were randomly assigned to either the grief support team's protocol of care or to the control group who received routine hospital care. Assessment was carried out on 34 participants, 16 from the control group and 18 from the treatment, 6 months after delivery. A three-part self-administered, self-rating grief index questionnaire was used. There was no statistical difference on overall grief scores between the two matched groups. The treatment group reported significantly lower scores than the control group on the two grief subscales of anger-hostility and physical symptoms. Women who reported more life changes before the perinatal death tended to have fewer problems with the symptomatology of grief. Social support was an important variable in explaining grief symptomatology. Women reporting low levels of social support who were in the treatment group had significantly lower mean scores on the grief subscales of anger-hostility, somatic experience, physical symptoms, and problems with vigor.

Counseling↗