Clostridium septicum is a major cause of spontaneous, nontraumatic gas gangrene. Unlike Clostridium perfringens, C. septicum is relatively aerotolerant and thus appears to be more capable of initiating infection in the absence of obvious damage to tissues. Six cases illustrate the clinical setting and fulminant nature of spontaneous gangrene caused by C. septicum. A lesion in the colon such as carcinoma is often present and is presumed to serve as a portal of entry to the bloodstream. Diabetes and leukopenia are also common predisposing conditions; compromise of vital host responses may facilitate proliferation of those organisms that settle out in the tissues. Acute lymphoma or leukemia during a course of chemotherapy is accompanied by damage to bowel mucosa and granulocytopenia, thus predisposing to spontaneous clostridial gangrene. Infection progresses in a fulminating manner; the majority of patients die within 24 hours of onset. Characteristic symptoms and signs include excruciating pain (although a sense of heaviness may be the only early symptom), swelling of tissues, crepitance, and bulla formation. A hallmark of C. septicum infection is the absence of acute inflammatory cells in involved tissues or in bulla fluid. A series of laboratory investigations demonstrated that fluid obtained from a bulla adversely affected the viability, morphology, and function of polymorphonuclear leukocytes (PMNs), which may explain the paucity of PMNs in involved tissues and may in part contribute to the fulminant progression observed in infection due to this organism.

Adenocarcinoma↗

PubMedDate not supplied

Acquired immune deficiency syndrome (AIDS): speculations about its etiology and comparative immunology.

Acquired immune deficiency syndrome (AIDS) in many aspects resembles formerly recognized immune deficiencies, but in its complexity and presumed viral etiology, it is a unique entity. Examples of overlapping features of AIDS and immune defects, infectious complications, and neoplasms are discussed. It is not known what are the exact underlying mechanisms that permit or prohibit infectious and neoplastic complications among the immunodeficiency syndromes compared, but both overlapping and differing features of these entities are significant enough to hold a clue for future understanding. AIDS resembles feline leukemia as this latter syndrome was described 10 years ago. The retrovirus causing feline leukemia is highly immunosuppressive; preleukemic and viremic cats often succumb to opportunistic infections. If patients with early AIDS harbor retroviruses related to the human T cell leukemia virus in their organs (lymph nodes, bone marrow), serotherapy with monoclonal antibodies directed to this virus may stop and reverse the severe immunosuppression, thus preventing the development of opportunistic infections.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Endogenous DNA polymerase-positive core particles from hepatitis-infected hepatocytes.

The purification is described of liver-derived hepatitis B core antigen (HBc Ag) from human hepatocytes demonstrating only intranuclear particles by electron microscopy. The purified preparation contained 5 x 10(11) particles per ml. The particles were mono-dispersed and relatively free of background material. DNA-dependent polymerase activity was present and had greater activity than an equal number of cores derived from Dane particles isolated from plasma. Specificity of the polymerase reaction was confirmed by precipitation of the activity with specific anti-HBc antiserum. A proportion of the liver-derived core particles was nonreactive for DNA polymerase activity. The polymerase-positive population of particles had a larger size than the polymerase-negative population of liver-derived cores as evidenced by gel filtration in Sepharose 4B.

DNA-Directed DNA Polymerase↗

PubMedDate not supplied

Mirror image aneurysms of the ulnar artery in the palm.

A case of sequential bilateral ulnar artery aneurysms in the palm is reported. Thirty-five unilateral true aneurysms in the hypothenar area are reported in the literature and most have been associated with repeated trauma to the palm. The diagnosis is easily established from physical examination. Definition of the anatomic relationships of the aneurysm is by selective arteriography. Surgical excision or ligation of the communicating arteries is curative.

Aneurysm↗

PubMedDate not supplied

Origin and significance of intranuclear tubular inclusions in type II pulmonary alveolar epithelial cells of patients with bleomycin and busulfan toxicity.

Abundant intranuclear tubular structures were observed in type II alveolar pneumocytes in lung biopsies from patients with bleomycin and busulfan toxicity. It is proposed that since chromatin-membrane interactions in eukaryotic cell nuclei do occur, the intranuclear proliferation of the tubular structures occurs as a result of the interaction of the drug with perichromatin.

Bleomycin↗