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Biomedical subjects

T Rosen

Publications and source records attributed to T Rosen.

At least 109 records · Page 6Linked to original sources
PubMed1990

Cutaneous cryptococcosis simulating Kaposi's sarcoma in the acquired immunodeficiency syndrome.

A forty-one-year-old homosexual man with acquired immunodeficiency syndrome (AIDS) and biopsy proven Kaposi's sarcoma of the oral cavity presented to our clinic with a several month history of violaceous papules and plaques on his trunk and extremities. Although the patient already carried a clinical diagnosis of Kaposi's sarcoma, several biopsies of skin lesions were performed. Tissue specimens demonstrated cutaneous infection with Cryptococcus neoformans. As patients with AIDS have an increased incidence of both Kaposi's sarcoma and opportunistic infections, all progressing lesions should be biopsied in order to avoid missing a treatable life-threatening disease.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Mechanism of inhibition of DNA gyrase by quinolone antibacterials: a cooperative drug--DNA binding model.

We have proposed a cooperative quinolone-DNA binding model for the inhibition of DNA gyrase. The essential feature of the model is that bound gyrase induces a specific quinolone binding site in the relaxed DNA substrate in the presence of ATP. The binding affinity and specificity are derived from two unique and equally important functional features: the specific conformation of the proposed single-stranded DNA pocket induced by the enzyme and the unique self-association phenomenon (from which the cooperativity is derived) of the drug molecules to fit the binding pocket with a high degree of flexibility. Supporting evidence for and implications of this model are provided.

Anti-Bacterial Agents↗
PubMed1989

Papulonodular demodicidosis associated with acquired immunodeficiency syndrome.

We describe a papulonodular variant of demodicidosis seen in two patients with acquired immunodeficiency syndrome and its successful treatment with 1% gamma benzene hexachloride and 1% permethrin cream rinse. Alterations in T cell function may allow otherwise commensal organisms to proliferate to the point of causing disease.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Pityriasis folliculorum revisited.

Six cases of facial erythema with follicular plugging are described. These cases correspond with characteristics of the disorder pityriasis folliculorum, a presumed demodicidosis. Treatment modalities included topical tretinoin, gamma benzene hexachloride (lindane) lotion, and 1% permethrin cream rinse.

Adult↗
PubMed1989

Carcinoembryonic antigen in basal cell neoplasms in black patients: an immunohistochemical study.

The development of skin cancer in black persons is rare, and basal cell epitheliomas are the most uncommon. Eight tumors were evaluated by routine histochemistry examination and immunoperoxidase staining for carcinoembryonic antigen (CEA). Our results demonstrate that half these tumors showed a positive reaction to this antigen, supporting the adnexal origin/differentiation of these lesions. Sixteen (16/18) similar tumors from white patients failed to show equivalent features. In addition, some of these CEA-positive tumors seem to demonstrate less aggressive behavior.

Adult↗
PubMed1989

Aromatic dienoyl tetramic acids. Novel antibacterial agents with activity against anaerobes and staphylococci.

Streptolydigin (1) and tirandamycin A (2) are typical members of the naturally occurring class of 3-dienoyl tetramic acids. These compounds, which possess potent antibacterial activity particularly against anaerobes, have been shown to inhibit bacterial RNA polymerase. In contrast, tenuazonic acid (5), which lacks a complex dioxabicyclononane moiety and diene chromophore present in 1 and 2, exhibits essentially no antimicrobial activity and has no effect on bacterial RNA polymerase, suggesting that one or both of these structural features may be critical for antibacterial activity. In this paper, we report on a novel series of synthetic dienoyl tetramic acids that lack a complex dioxabicyclononane unit. Several of these compounds, particularly 8T-W, exhibit potent antimicrobial activity against Gram-positive and Gram-negative anaerobes as well as staphylococci. We will discuss the structure-activity relationship for this series of compounds which, in contrast to their natural counterparts, do not inhibit significantly RNA polymerase. We will also discuss preliminary results on the biochemical and microbiological properties of this series of compounds, several of which moderately inhibit supercoiling by DNA gyrase isolated from E. coli H560, although this enzyme has not been established as their target in whole cells. Compound 8W, which is not cross-resistant with DNA gyrase subunit A or B inhibitors or tirandamycin, has also been demonstrated to be rapidly bactericidal.

Anti-Bacterial Agents↗
PubMed1989

Acute radiodermatitis from occupational exposure to iridium 192.

Industrial radiography using the man-made radioisotope iridium 129 is commonplace in the southern states. Despite established procedures and safeguards, accidental exposure may result in typical acute radiodermatitis. We have presented a clinical example of this phenomenon.

Acute Disease↗
PubMed1989

Nail discoloration due to mahogany.

A patient is described in whom orange-brown discoloration occurred following occupational exposure to mahogany wood. Mahogany-induced dermatitis is reviewed.

Adult↗
PubMed1989

Vesicular Jarisch-Herxheimer reaction.

The Jarisch-Herxheimer reaction is a self-limited, febrile episode that may occur following antibiotic therapy for syphilis. We report four cases of a heretofore unrecognized vesicular variant of the Jarisch-Herxheimer reaction. It is important to distinguish this phenomenon from an allergic drug eruption.

Adult↗
PubMed1988

Radiation port dermatophytosis.

We report two cases in which dermatophytic infection developed almost entirely within a radiation field mimicking an acute radiation effect. Radiotherapists and dermatologists should be aware of this possibility and be able to differentiate it from radiation dermatitis. Topical antifungal agents are the recommended treatment after diagnosis is established.

Adult↗
PubMed1988

Asymmetric synthesis and properties of the enantiomers of the antibacterial agent 7-(3-aminopyrrolidin-1-yl)-1-(2,4-difluorophenyl)-1,4-dihydro-6- fluoro-4-oxo-1,8-naphthyridine-3-carboxylic acid hydrochloride.

Compound 1 [7-(3-aminopyrrolidin-1-yl)-1-(2,4-difluorophenyl)-1,4-dihydro-6-f luoro-4-oxo-1,8-naphthyridine-3-carboxylic acid hydrochloride] is a potent member of the quinolonecarboxylic acid class of antibacterial agents and is currently undergoing clinical evaluation. We have developed efficient asymmetric syntheses of the enantiomers of this agent. The S-(+) enantiomer 1a is 1-2 log2 dilutions more active than the R-(-) enantiomer 1b against aerobic bacteria and 1-2 or more log2 dilutions more active against anaerobic bacteria in vitro. The enantiomer 1a shows significantly better in vivo activity in a Pseudomonas aeruginosa mouse protection model compared to racemic 1. Coupled with the improved solubility profile of 1a relative to racemic material, these features may be of practical significance from a clinical standpoint.

Anti-Bacterial Agents↗
PubMed1988

Design, synthesis, and properties of (4S)-7-(4-amino-2-substituted-pyrrolidin-1-yl)quinolone-3-carboxylic acids.

The quinolonecarboxylic acids constitute a class of extremely potent and orally active broad-spectrum antibacterial agents. These compounds have been shown to inhibit DNA gyrase, a key enzyme in bacterial DNA replication. The 7-(3-aminopyrrolidinyl)quinolone A-60969 (1) is a particularly potent member of this class and is currently undergoing clinical evaluation. We have studied a series of enantiomerically homogeneous (4S)-7-(4-amino-2-substituted-pyrrolidinyl)quinolones in an effort to utilize the 2-position of the pyrrolidine moiety to improve upon the solubility and pharmacokinetic properties of this class of compounds while still maintaining potent antibacterial activity. We have found that the absolute stereochemistry at the 2-position of the pyrrolidine ring is critical to the maintenance of such activity. In this paper, we report the full details of the asymmetric synthesis and the in vitro and in vivo structure-activity relationships of this series of compounds as well as the physiochemical properties, such as water solubility and log P, associated with the structural modifications. We also discuss the pharmacokinetic properties of several of these compounds in mice and the pharmacokinetics of 59, which has the best overall properties of agents in this study, in dog.

Animals↗
PubMed1988

Zosteriform metastasis: case presentation and review of the literature.

In contrast to benign tumors, malignant tumors, by definition, are characterized by the potential of giving rise to metastases. Albeit infrequently, skin metastases do occur, and their clinical appearance varies over a wide morphologic spectrum. We present the case of a 65-year-old male with zosteriform metastasis secondary to bronchogenic adenocarcinoma. A review of cutaneous metastasis is presented with emphasis on dermatomal distribution and possible mechanisms of dissemination.

Adenocarcinoma↗
PubMed1988

Vibrio vulnificus septicemia.

We report a case of Vibrio vulnificus infection in a middle-aged alcoholic man with Laennec's cirrhosis. The patient had recently received a puncture wound from the shell of a shrimp while fishing in the Gulf of Mexico. He presented with acrally distributed urticarial plaques, purpura, and bullae, as well as signs and symptoms of septic shock. Vibrio vulnificus was isolated from the blood, and histologic examination of the skin biopsy specimen demonstrated a devitalized, inflammatory, cell-poor superficial dermis and an acute cellulitis of the subcutis, with extensive tissue destruction. In addition, a necrotizing vasculitis, with a relative paucity of inflammatory cells but numerous bacilli around dermal vessels, was noted.

Humans↗