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Biomedical subjects

S D Vincent

Publications and source records attributed to S D Vincent.

At least 19 recordsLinked to original sources
PubMed1994

Branch migration of Holliday junctions: identification of RecG protein as a junction specific DNA helicase.

The product of the recG gene of Escherichia coli is needed for normal recombination and DNA repair in E. coli and has been shown to help process Holliday junction intermediates to mature products by catalysing branch migration. The 76 kDa RecG protein contains sequence motifs conserved in the DExH family of helicases, suggesting that it promotes branch migration by unwinding DNA. We show that RecG does not unwind blunt ended duplex DNA or forked duplexes with short unpaired single-strand ends. It also fails to unwind a partial duplex (52 bp) classical helicase substrate containing a short oligonucleotide annealed to circular single-stranded DNA. However, unwinding activity is detected when the duplex region is reduced to 26 bp or less, although this requires high levels of protein. The unwinding proceeds with a clear 3' to 5' polarity with respect to the single strand bound by RecG. Substantially higher levels of unwinding are observed with substrates containing a three-way duplex branch. This is attributed to RecG's particular affinity for junction DNA which we demonstrate would be heightened by single-stranded DNA binding protein in vivo. Reaction requirements for unwinding are the same as for branch migration of Holliday junctions, with a strict dependence on hydrolysis of ATP. These results define RecG as a new class of helicase that has evolved to catalyse the branch migration of Holliday junctions.

Bacterial Proteins↗
PubMed1994

Clinical and therapeutic features of polymorphous low-grade adenocarcinoma.

Polymorphous low-grade adenocarcinoma, also known as terminal duct or lobular carcinoma, was first described in two clinical case series in 1983. Before that time most of these neoplasms were diagnosed as benign salivary gland neoplasms including pleomorphic adenomas, variants of monomorphic adenomas, or salivary malignant conditions including malignant pleomorphic adenomas, adenoid cystic carcinomas, and adenocarcinoma not otherwise stated. This neoplasm with few exceptions originates in minor salivary gland tissue of the posterior hard and soft palates or buccal mucosa. It is characteristically slow to enlarge; clinical reports show the neoplasm present for many years before diagnosis. We have evaluated the clinical and microscopic features of 15 cases from the archives of The University of Iowa Surgical Oral Pathology Laboratory and added these to published case reports. A total of 204 cases were evaluated with a female/male ratio of almost 2/1. Forty-nine percent originated in palatal mucosa. Polymorphous low-grade adenocarcinomas arising from pleomorphic adenomas or de novo have been reported within major salivary glands and outside the oral cavity. A 17% recurrence rate was found with a regional metastasis rate of 9%. Five cases had multiple recurrences, and 13 recurrences were at or beyond 5 years after the initial diagnosis. Regional node metastases were identified at the time of initial treatment or at the time of recurrence in 9% of cases in which follow-up data were specified.

Adenocarcinoma↗
PubMed1994

Prostaglandin E2 and interleukin-1 levels in smokeless tobacco-induced oral mucosal lesions.

Inflammatory mediators released as a result of smokeless tobacco (ST)-induced irritation may play a role in the development of oral mucosal lesions at habitual tobacco placement sites in ST users. The present study examined levels of interleukin-1 (IL-1) and prostaglandin E2 (PGE2) in ST-induced mucosal lesions and compared these to mediator levels in clinically normal mucosa. Soft tissue biopsies were obtained from white mucosal lesions at habitual placement sites and normal alveolar mucosal tissue at non-placement sites in 18 ST users. Fifteen non-tobacco using subjects also provided normal alveolar mucosal biopsies. IL-1 and PGE2 were recovered from the specimens, and mediator levels were determined by enzyme immunoassay. Prostaglandin E2 levels (pg/mg) were lower in both regions in the ST subjects, but values did not vary significantly between the regions with 2.77 +/- 0.72 and 2.86 +/- 0.99 at placement and non-placement sites, respectively, in ST users and 7.31 +/- 3.84 in non-tobacco users. Both IL-1 alpha and IL-1 beta (pg/mg) were significantly (p < 0.01) elevated in ST lesions (IL-1 alpha = 25.56 +/- 4.00; IL-1 beta = 7.76 +/- 1.68) compared to either non-placement sites in ST users (IL-1 alpha = 14.64 +/- 2.65; IL-1 beta = 1.63 +/- 0.72) or non-tobacco users (IL-1 alpha = 12.84 +/- 2.60; IL-1 beta = 2.04 +/- 0.75). In view of IL-1's role in keratinocyte proliferation and its inflammatory effects, this cytokine may contribute to mucosal and gingival alterations observed in ST users.

Adult↗
PubMed1994

Abuse history and chronic pain in women: I. Prevalences of sexual abuse and physical abuse.

OBJECTIVE: To compare the prevalences of childhood and adult physical and sexual abuse in women with chronic pelvic pain to those in women with chronic nonpelvic pain (headache) and pain-free women. METHODS: Using a structured interview, we assessed the prevalence rates of both sexual abuse and physical abuse in 64 women with chronic pelvic pain, 42 women with chronic headache, and 46 pain-free women. Abuse histories were stratified by age at occurrence and severity. Demographic characteristics of the three groups were also assessed. RESULTS: Women with chronic pelvic pain were found to have a higher lifetime prevalence of sexual abuse, involving penetration or other contact with the unclothed genitals or anus (ie, major sexual abuse), than either comparison group. Further, more women in the chronic pelvic pain group had experienced major sexual abuse in both childhood and adulthood than women in the headache group, but there was no difference with the pain-free group. With respect to physical abuse, women in the chronic pelvic pain group had a higher lifetime prevalence than pain-free women, but not compared to those with chronic headache. In addition, more women with chronic pelvic pain reported physical abuse in both childhood and adulthood and both major sexual abuse and physical abuse at some time in their lives than did either comparison group. CONCLUSIONS: These results support a specific association between major sexual abuse and chronic pelvic pain and a more general association between physical abuse and chronic pain. Moreover, the global nature of the abuse histories of the women in the chronic pelvic pain group suggests that more rigorous studies of the relation between abuse history and chronic pelvic pain are needed.

Adolescent↗
PubMed1994

Abuse history and chronic pain in women: II. A multivariate analysis of abuse and psychological morbidity.

OBJECTIVE: To assess the potential role of childhood and adulthood physical and sexual abuse and complaints of chronic pain in accounting for psychiatric symptomatology in adult women. METHODS: We assessed sexual abuse, physical abuse, depression, anxiety, and somatization in 64 women with chronic pelvic pain, 42 women with chronic headache, and 46 women without chronic pain complaints. Using multiple regression analyses, we tested a model comprising sociodemographic, chronic pain, childhood sexual abuse and physical abuse, and adulthood sexual abuse and physical abuse variables in the prediction of depression, anxiety and somatization. RESULTS: This model significantly predicted all three outcomes. However, childhood sexual abuse was not significant in the prediction of any of the outcome variables, whereas childhood physical abuse was significant in the prediction of all three. Further, the adulthood abuse variable set contributed significantly to the prediction of somatization, and the individual variable of adulthood sexual abuse was predictive of anxiety. CONCLUSIONS: The relation observed between childhood sexual abuse and the outcomes of depression, anxiety, and somatization in women may be a function of its association with other forms of abuse, particularly childhood physical abuse. Further investigation is clearly needed of the nature of the relations between the various categories of abuse and psychological morbidity.

Adolescent↗
PubMed1993

Clinical, historic, and therapeutic features of cicatricial pemphigoid. A literature review and open therapeutic trial with corticosteroids.

Cicatricial pemphigoid is at present an incurable, autoimmune disease that involves mucosa and skin. We have documented the clinical, microscopic, and therapeutic features of 23 patients with cicatricial pemphigoid and added these to reports of past literature. The mean age at the time of diagnosis was 63 years, and women were involved twice as often as men. Eighty-three percent of patients had oral mucosal involvement, 70% had conjunctival involvement, and 22% had skin involved. Direct immunologic evaluation revealed IgG at the basement membrane in 57% of cases and C3 in 66%. We have been able to manage the disease adequately in most patients with topical or systemic corticosteroids. The most commonly encountered side effect was oral candidiasis.

Aged↗
PubMed1992

Oral candidosis. Clinical, historical, and therapeutic features of 100 cases.

Oral candidosis is an increasingly important disease that affects a significant percentage of the population. Traditionally known as an opportunistic pathogen, the broader clinical scope of oropharyngeal candidal infections is now being recognized. The clinical and historical features of 100 patients referred for diagnosis and management of candidosis have been reviewed. The age, gender, chief complaint, medical history, medications, and clinical findings have been noted. A wide range of clinical signs and symptoms, and the rationale behind the topical and systemic antifungal therapies provided to this patient population, are discussed.

Administration, Oral↗
PubMed1992

Clinical, historic, and therapeutic features of aphthous stomatitis. Literature review and open clinical trial employing steroids.

The clinical and historic features of 50 patients with diagnosed aphthous stomatitis and treated with topical triamcinolone acetonide, 0.1% or 0.2% aqueous suspension; alone or in combination with initial burst therapy of 40 to 60 mg of prednisone, are reviewed. The mean age of our patients was 36.6 years (range 6 to 80 years). The duration of the chief complaint, usually oral pain, or more specifically, recurrent oral ulcers, was 11.1 years (range 4 weeks to 40 years). All patients showed a wide range of ulcer sizes when examined initially or at follow-up. Forty were followed up for an average of 22.9 months. Thirty-four reported prompt healing of ulcers identified at the time of initial evaluation, and no or markedly fewer ulcers subsequently if maintenance therapy of prophylactic topical triamcinolone, 0.1% or 0.2% aqueous rinse, was used. Five patients reported partial relief. No systemic side effects were noted even after long-term topical therapy. Local candidosis was a complication encountered in five patients.

Administration, Oral↗
PubMed1992

Diagnosis and management of autoimmune and idiopathic mucosal diseases.

Several autoimmune and idiopathic diseases directly affect the oral mucosa. Current therapeutic management is aimed primarily at the control and prevention of symptoms. It is important for patients to understand the goals of therapeutic management because these diseases often are characterized by periods of remission and exacerbation that require long-term follow-up.

Autoimmune Diseases↗