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Biomedical subjects

T M Johnson

Publications and source records attributed to T M Johnson.

At least 73 records · Page 4Linked to original sources
PubMed1998

The association of urinary incontinence with poor self-rated health.

OBJECTIVES: To assess whether urinary incontinence (UI) and its severity are associated with poor self-rated health in a national sample of community-living older adults and whether this relationship persists after controlling for confounding attributable to functional status, comorbidity, and demographic factors. DESIGN: A cross-sectional analysis using multivariate logistic regression. SETTING: Subjects were from the 1990-1991 National Survey of Self-Care and Aging (N = 3485), a random sampling in geographic clusters of community-dwelling Medicare beneficiaries 65 years of age or older in the contiguous United States. MEASURES: The responses to an interviewer-administered questionnaire regarding urinary incontinence, Basic Activities of Daily Living (BADL), Instrumental Activities of Daily Living (IADL), Mobility Activities of Daily Living (MADL), age, gender, place of residence, race, education, need for proxy response to the survey, and number of medical conditions. RESULTS: Unadjusted analysis showed the presence of urinary incontinence to be associated with poor self-rated health (OR 2.7, 2.1-3.3). With gender, number of comorbid conditions, race, IADL impairment, and interaction terms of incontinence/race and incontinence/IADL in the final model, UI was associated with poor self-rated health in certain subgroups. White subjects with no IADL impairment and mild-moderate incontinence had an OR of 2.0 (95% CI 1.5-2.9) and those with severe incontinence had an OR of 4.5 (95% CI 2.4-8.4) of rating their health as poor, whereas those with no IADL impairment and no incontinence were the referent group. For those with a lot of difficulty performing one or more IADL activity, the association of UI and poor self-rated health was weak. For non-white subjects, there was no association, or a very weak association, of UI and poor self-rated health. CONCLUSION: In this national sample, urinary incontinence was independently and positively associated with poor self-rated health after adjustment for age, comorbidity, and frailty for most community-dwelling older adults. This association between UI and poor self-rated health was weaker and statistically insignificant when IADL impairment was present or in non-white subjects. Further research is indicated to better understand the impact of urinary incontinence in specific cultural settings.

Activities of Daily Living↗
PubMed1998

Urinary incontinence.

The involuntary loss of urine in a quantity or frequency sufficient to cause a social or hygienic problem is known as urinary incontinence. This common condition, affecting over 10 million adults, afflicts an estimated 30% of all older persons, as well as 50% to 70% of older residents in nursing homes. The clinical importance of urinary incontinence is due primarily to its adverse effects on psychologic health and social interactions; effects on physical health, such as skin maceration and recurrent urinary tract infections, are relatively minor. Because symptomatic improvement or cure is possible in many cases, health care providers should ask specific questions about symptoms of urinary incontinence and then provide appropriate evaluation and management of this common condition.

Aged↗
PubMed1997

Pertussis toxin-sensitive G proteins as mediators of the signal transduction pathways activated by cytomegalovirus infection of smooth muscle cells.

We demonstrated recently that the arachidonic acid (AA) cascade is involved in cytomegalovirus (CMV)-induced generation of reactive oxygen species (ROS) and the activation of nuclear factor (NF)-kappaB in human smooth muscle cells (SMCs). Since AA release from neutrophils is mediated by pertussis toxin (PTx)-sensitive guanine nucleotide-binding (G) proteins, we hypothesized by analogy that CMV stimulates ROS generation in SMCs and ultimately activates NF-kappaB via a PTx-sensitive G protein-coupled pathway. Our first test of this hypothesis demonstrated that PTx blocked AA release induced by CMV infection of SMCs, as well as blocked the terminal products of this reaction, ROS generation and NF-kappaB activation. More proximal components of the pathway were then examined. CMV infection increased phosphorylation and activity of cytosolic phospholipase A2 (cPLA2), an enzyme causing AA release; these effects were inhibited by PTx. CMV infection activated mitogen-activated protein (MAP) kinase, a key enzyme for cPLA2 phosphorylation, an effect also inhibited by PTx. Finally, inhibition of MAP kinase kinase (MAPKK), which phosphorylates and thereby activates MAP kinase, inhibited CMV-induced ROS generation. These data demonstrate that a PTx-sensitive G protein-dependent signaling pathway mediates cellular effects of CMV infection of SMCs. The downstream events include phosphorylation and activation of MAP kinase by MAPKK and subsequent phosphorylation and activation of cPLA2 (with its translocation to cell membranes), followed by stimulation of the AA cascade, which generates intracellular ROS and thereby activates NF-kappaB.

Aorta↗
PubMed1997

Rac1 is required for cell proliferation and G2/M progression.

We have transiently expressed a dominant negative form of rac1 (N17rac1) using adenoviral-mediated gene transfer. The level of N17rac1 expression is demonstrated to be proportional to the multiplicity of infection. Expression of N17rac1 in Rat 2 fibroblasts results in cytostatic growth arrest. Cell-cycle analysis demonstrates that cells expressing N17rac1 accumulate in G2/M. These results suggest that rac1 is required for cell proliferation and provide the first demonstration in mammalian cells of a role for small GTP-binding proteins in the G2/M transition.

Adenoviridae↗
PubMed1997

CaN19 expression in benign and malignant hyperplasias of the skin and oral mucosa: evidence for a role in regenerative differentiation.

CaN19, a member of the S100 family of calcium-binding proteins, is known to be "underexpressed" in cultured breast carcinoma-derived cell lines relative to their normal counterparts. By Northern blotting, we confirm these results and find that CaN19 is also markedly "underexpressed" in several carcinoma-derived cell lines of the skin, oral mucosa, and urogenital tract. However, exceptions to the inverse correlation between CaN19 expression and malignancy have been identified, bringing into question the hypothesis that CaN19 functions as a tumor suppressor gene. Unexpectedly, CaN19 mRNA was strongly expressed in bulk specimens of basal and squamous cell carcinomas of the skin and oral cavity. However, in situ hybridization revealed only limited CaN19 expression in tumor cells themselves; the bulk of expression is localized to hyperplastic perilesional epidermis. Tumor cell expression of CaN19 was similar in primary and locally metastatic tumors, indicating that this gene is not necessarily down-regulated during tumor progression. Coordinate overexpression of CaN19 and the "hyperproliferalive" keratin K6a was observed only in tissues undergoing squamous differentiation. Taken together with other recent results from our laboratory, these findings suggest the hypothesis that CaN19 participates in an epidermal growth factor receptor-dependent pathway of regenerative squamous differentiation.

Basal Cell Carcinoma↗
PubMed1997

The staged retroauricular to auricular direct pedicle (interpolation) flap for helical ear reconstruction.

BACKGROUND: A significant soft-tissue defect involving the helix of the external ear may present a difficult challenge to repair. OBJECTIVE: We describe our experience with the staged retroauricular to auricular pedicle flap for repair of soft-tissue defects with exposed cartilage of the helix of the ear. METHODS: The staged pedicle flap was used to repair 26 helical ear defects after excision of basal cell carcinoma (n = 16), squamous cell carcinoma (n = 3), and melanoma (n = 7). RESULTS: Defect size ranged from 1 x 2 cm to 4 x 6 cm (average 2.4 x 3.3 cm). Defects involved the superior helix in 12 patients, mid helix in 11, and inferior helix in three. No cases of infection or flap necrosis occurred. CONCLUSION: The staged retroauricular to auricular pedicle flap consistently provides a good to excellent functional and cosmetic outcome when performed on properly selected helical ear defects.

Basal Cell Carcinoma↗
PubMed1997

Usefulness of the staged excision for lentigo maligna and lentigo maligna melanoma: the "square" procedure.

BACKGROUND: Management of lentigo maligna (LM) and lentigo maligna melanoma (LMM) may present problems because of the characteristic, yet unpredictable, subclinical peripheral and periadnexal extension of atypical junctional melanocytic hyperplasia beyond the visible margins. OBJECTIVE: We used paraffin-embedded (permanent) peripheral vertical section margin control in a staged fashion in the management of LM and LMM. METHODS: We used a modification of surgical excision in a staged fashion by means of a two-bladed knife with permanent peripheral vertical section margin control. RESULTS: This method is technically easy and results in complete histologic evaluation of the peripheral margins without compromising the measurement of tumor thickness of the primary melanoma. CONCLUSION: The use of the "square" procedure, a staged excision with permanent peripheral vertical section margin control, is useful in the management of LM and LMM.

Biopsy↗
PubMed1997

Mohs micrographic surgery for the treatment of dermatofibrosarcoma protuberans. Results of a multiinstitutional series with an analysis of the extent of microscopic spread.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is an uncommon soft-tissue tumor of the skin; its microscopic extent of invasion beyond the grossly visible tumor is frequently difficult to appreciate. Although wide local excision has been the standard treatment of DFSP, recurrence rates range from 11% to 53%. Because Mohs micrographic surgery allows the extent of excision to be tailored to the microscopic extent of tumor, we evaluated this technique for the treatment of primary and recurrent DFSP. OBJECTIVE: Our purpose was to determine the local recurrence rate and microscopic extent of spread of primary and recurrent DFSP after treatment with Mohs micrographic surgery. METHODS: The records of 58 patients with primary and recurrent DFSP treated with Mohs micrographic surgery at three institutions were reviewed and the macroscopic and microscopic extents of tumor were recorded. RESULTS: One patient with a twice-recurrent DFSP had another recurrence after Mohs micrographic surgery, for an overall local recurrence rate of 2% (zero for primary tumors and 4.8% for recurrent tumors). There were no cases of regional or distant metastases. Macroscopic tumor size ranged from 0.3 x 0.6 cm to 30 x 20 cm, whereas microscopic (postoperative) size ranged from 1.8 x 1.0 cm to 35 x 40 cm. We calculated the likelihood that a given width of excision around the macroscopic tumor would clear the entire microscopic extent of tumor. Standard wide excision with a width of 1 cm around the primary tumor would have left microscopic residual tumor in 70.7%; a width of 2 cm, 39.7%; 3 cm, 15.5%; and 5 cm, 5.2%. Even an excision width of 10 cm would not have cleared the microscopic extent of some tumors, despite taking a huge excess of normal tissue. CONCLUSION: Treatment of primary and recurrent DFSP by Mohs micrographic surgery results in a low recurrence rate because of the ability of the technique to permit the detection and excision of microscopic tumor elements in even the most asymmetric tumors. Whatever type of surgery is chosen to treat DFSP, it is necessary to assess the entire perimeter of the tumor for microscopic extension and to achieve tumor-free margins in all directions.

Adolescent↗
PubMed1997

The staged cheek-to-nose interpolation flap for reconstruction of the nasal alar rim/lobule.

BACKGROUND: A deep defect of the nasal alar rim or lobule may represent a unique and difficult challenge because of the lax free margin and structural support supplied by the alar rim and lobule. Traditional closure strategies, including granulation, full thickness skin grafting, or nasolabial transposition flaps may result in unsatisfactory cosmetic and functional outcomes. OBJECTIVE: This article describes our experience with the staged cheek-to-nose interpolation flap for repairing deep skin cancer excision defects of the nasal alar rim and lobule. METHODS: The staged cheek-to-nose interpolation flap was used immediately after Mohs micrographic surgery to repair 18 deep nasal alar rim/lobule defects. In 13 patients, a free cartilage graft was used to restore structural support. RESULTS: The cosmetic and functional outcomes of each repair were judged from good to excellent by patient and surgeon. No cases of infection or flap necrosis occurred. To enhance the cosmetic outcome, three patients underwent spot dermabrasion within 2 months after flap detachment. CONCLUSION: The staged cheek-to-nose interpolation flap, with or without free cartilage grafts, consistently provides good to excellent cosmetic and functional outcomes when performed on properly selected deep nasal alar rim/lobule defects.

Cartilage↗
PubMed1997

Medical issues and emergencies in the dermatology office.

We review the medical issues and emergencies potentially encountered in the practice of general or surgical dermatology. Traditional guidelines have largely consisted of dated extrapolations from the nondermatologic literature concerning procedures that are primarily irrelevant to dermatology. This article outlines a rational approach to organizing an office emergency plan for anaphylaxis, stroke, status epilepticus, myocardial infarction, and hypertensive crisis. We discuss the literature that has influenced current office behavior regarding endocarditis prophylaxis, the use of electrosurgery with pacemakers, arrhythmogenic drug interactions, vasovagal syncope, lidocaine "allergy," and bleeding complications from oral anticoagulants. Recommendations for managing these issues in a dermatologic context are provided.

Anaphylaxis↗
PubMed1997

The utility of fine needle aspiration in the diagnosis of melanoma metastatic to lymph nodes.

BACKGROUND: Prompt and accurate diagnosis of melanoma metastatic to the lymph nodes is important with respect to prognosis and treatment. OBJECTIVE: The purpose of this study was to determine the utility and diagnostic reliability of fine needle aspiration (FNA) of enlarged nodules in lymph node basins in patients with melanoma. METHODS: We retrospectively reviewed the charts of 46 patients with melanoma who underwent a total of 56 FNAs of palpable nodules in lymph node basins. RESULTS: Of the 56 FNAs, 24 showed melanoma, 26 did not demonstrate melanoma, five were inadequate, and one gave inconclusive but suspect results. Findings were confirmed by open biopsy (n = 35) or clinical follow-up (n = 21). Fifty of 56 FNAs (89%) yielded a definitive diagnosis (sensitivity/specificity = 100% in these 50). CONCLUSION: FNA biopsy of enlarged palpable nodules in nodal basins in patients with melanoma is accurate, rapid, and cost-efficient. An algorithm for management of patients with melanoma who have palpable nodes is provided.

Adult↗
PubMed1997

Mucinous carcinoma of the skin.

Primary mucinous carcinoma of the skin is a rare adnexal neoplasm with sweat gland differentiation. We describe a case of primary mucinous carcinoma of the skin and characterize its clinical and histologic features. Mucinous carcinoma can occur in noncutaneous visceral sites and may metastasize to the skin. Thus it is important to exclude the possibility of a noncutaneous visceral primary tumor before diagnosing primary mucinous carcinoma of the skin.

Adenocarcinoma, Mucinous↗
PubMed1997

Diagnostic assessment of geriatric urinary incontinence.

Urinary incontinence affects 15% to 30% of the population and 50% of those living in nursing homes. Care for incontinence is difficult because this condition is underreported by patients and underdiagnosed by physicians. This article describes the medical and nursing diagnostic assessment of urinary incontinence of geriatric populations, and the criteria for referral. Comprehensive review of urinary incontinence, including treatment, is available elsewhere. Although this article focuses on the assessment of urinary incontinence, the type of treatment being considered guides the scope of the evaluation, and therefore, treatment of incontinence is discussed.

Aged↗
PubMed1997

Common and differential recognition of structural features in synthetic peptides by the catalytic domain and the Src-homology 2 (SH2) domain of pp60c-src.

The relative efficiencies of the catalytic domain of the src-family kinase pp60c-src in phosphorylating four peptide substrates including (i) src-optimal peptide (AEEEIYGEFEAKKKK), (ii) "-YEEI-peptide" (KKTHQEEEEPQYEEIPIYL), (iii) cdc2(6-20) (KVEKIGEGTYGVVYK), (iv) src-autophosphorylation site peptide (ADFGLARLIEDNEYTARG) and the relative efficiencies of its SH2 domain in binding the phosphorylated forms of these peptide substrates were compared. The results show that the src-optimal peptide, "-YEEI-peptide," cdc2(6-20) peptide were phosphorylated by the catalytic domain with high efficiency and that the phosphorylated form of all three peptides could bind the SH2 domain of the kinase, confirming the hypothesis proposed by Songyang and co-workers that the catalytic domain of pp60c-src phosphorylates sites which are recognized by its own SH2 domain (Songyang et al. (1995) Nature 373, 536-539). The four peptides were phosphorylated by the kinase with relative efficiencies in the order of Src-optimal peptide > "-YEEI-peptide" > cdc2(6-20) >> src-autophosphorylation site peptide. However, the Tyr(P)-Src-optimal peptide and [pY]15cdc2(6-20) bound to the SH2 domain of the kinase with an affinity at least an order of magnitude lower than that of the tight-binding peptide, "-pYEEI-peptide." Thus, our study suggests that the catalytic and SH2 domains of pp60c-src recognize overlapping but not identical determinants in the local structure around the tyrosine phosphorylation site of the substrate peptides.

Amino Acid Sequence↗
PubMed1997

A surgical wound infection due to Mycobacterium chelonae successfully treated with clarithromycin.

BACKGROUND: Mycobacterium chelonae is an uncommon but recognized cause of chronic localized cutaneous infection at a site of penetrating trauma or a surgical wound. OBJECTIVE: The problem faced by physicians encountering an infection by M. chelonae is often response to therapy, which may be highly variable. METHODS: We describe an immunocompetent patient who developed a localized infection due to M. chelonae following surgery for a basal cell carcinoma of the lower leg. RESULTS: The infection responded to treatment with clarithromycin. CONCLUSION: The clinical efficacy of clarithromycin and the salient features of M. chelonae infection and its treatment are discussed.

Aged↗
PubMed1997

Evaluating the hyperactive child in your office: is it ADHD?

When confronted with the complaints of hyperactivity and impulsivity in a child, the family physician may find it tempting to initiate a complex process leading to the diagnosis of attention-deficit hyperactivity disorder, which is arguably the most prevalent neurobiologic disorder in childhood. While the diagnosis of attention-deficit hyperactivity disorder cannot be made solely on the basis of office visits, a practical strategy for an initial assessment of hyperactivity and impulsivity in the examination room is extremely important. Careful observation of the child's behavior and strategic questioning of the parents can be helpful in differentiating volitional misbehavior from the neurologically based lack of behavioral control in attention-deficit hyperactivity disorder. A skilled initial office assessment allows more effective use of behavioral checklists and neuropsychologic tests, increases diagnostic confidence and provides a yardstick for measuring the effectiveness of treatment.

Attention Deficit Disorder with Hyperactivity↗