Biomedical subjects
Publications and source records attributed to M McCarty.
We present the case of a patient with the acquired immune deficiency syndrome (AIDS) who developed an ileo-ileal intussusception due to lymphoma of the small bowel. The clinical and radiographic findings are described.
We present the case of a homosexual male patient with the acquired immune deficiency syndrome (AIDS) who developed disseminated infection with Pneumocystis carinii. He presented with symptoms and signs of thyroid disease, and developed thyroid gland calcification. This was later histologically proven to be due to P. carinii infection. Disseminated P. carinii infection is rare, and this case represents the first report to our knowledge of thyroid gland involvement causing both hypothyroidism and calcification.
BACKGROUND: Kaposi's sarcoma is the most common secondary neoplasm to complicate HIV infection and may cause pulmonary disease. METHODS: A prospective study was carried out in 140 consecutive patients who were HIV seropositive and required bronchoscopy for new respiratory symptoms of at least two weeks' duration, with either a chest radiographic abnormality or abnormality of pulmonary function. The patients were classified into those with single local endobronchial lesions of Kaposi's sarcoma or generalised widespread lesions. Before bronchoscopy all patients had routine simple pulmonary function tests and chest radiography. RESULTS: Thirty nine (21%) patients had evidence of cutaneous Kaposi's sarcoma. Nineteen of the 39 were found to have endobronchial Kaposi's sarcoma lesions at bronchoscopy, but none of those who did not have cutaneous Kaposi's sarcoma. Respiratory symptoms of cough and breathlessness and radiographic abnormalities were attributed to Kaposi's sarcoma in this group, except in four patients who had concomitant pneumocystis pneumonia. Eight patients had local endobronchial Kaposi's sarcoma lesions and 11 had extensive lesions. Patients with extensive lesions had more widespread radiographic abnormalities; four of the patients with local endobronchial lesions had normal chest radiographs. All patients had reduced transfer factor for carbon monoxide and transfer coefficient, whereas patients with extensive endobronchial lesions also had reductions in forced expiratory volume in one second and forced vital capacity. Median survival (with palliative chemotherapy with vincristine and bleomycin) was only seven months. In three patients who needed further diagnostic bronchoscopy endobronchial lesions had regressed while they were having chemotherapy. CONCLUSIONS: This study suggests that endobronchial Kaposi's sarcoma is a relatively common finding in patients with AIDS and is particularly common in patients with cutaneous Kaposi's sarcoma who present with respiratory illness. Endobronchial Kaposi's sarcoma causes respiratory disease and abnormalities of pulmonary function. Pulmonary Kaposi's sarcoma should be considered as a possible cause for respiratory illness in any patient with cutaneous Kaposi's sarcoma.
Protoplasts of a group A streptococcal strain were shown to contain enzymatic activity capable of converting lipoteichoic acid (LTA) to deacylated lipoteichoic acid (dLTA). The enzyme(s) appear to be located mainly in the membrane, although activity was also found in the cytoplasm. Determination of the sites of cleavage within the LTA molecule was approached by comparing the chemical composition of LTA and native dLTA. Native dLTA, as distinguished from chemically deacylated LTA, was isolated from buffer in which live streptococci had been resuspended and incubated. The chemical data suggest that the enzyme(s) was(were) lipolytic in nature; that is, the conversion of LTA to dLTA was the result of cleavage of the ester linkages between the fatty acids and the remainder of the LTA molecule.
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The amino-terminal sequences of two peptides of type 24 streptococcal M protein show similarities with that of rabbit skeletal muscle tropomyosin, having up to 40% identical residues and probabilities of occurring by chance as low as P less than 10(-5). In addition, a hexapeptide (Glu-Ala-Glu-Lys-Ala-Ala) that is found five times in the M24 protein was shown to be identical to a sequence in tropomyosin. Similarities are also seen in the amino acid compositions and physicochemical properties of the two proteins. The amino-terminal sequences of peptides from another bacterial surface protein, staphylococcal protein A, are highly correlated with segments of two other myofibrillar proteins, rabbit actin (P less than 10(-7)) and rabbit myosin A1 light chain (P less than 10(-6)). The data presented suggest that a close structural relationship exists between mammalian muscle proteins and the biologically active surface proteins of staphylococci and streptococci. In addition, the correlation between sequences in M protein and tropomyosin represents direct evidence of a structural similarity at a molecular level between a streptococcal protein and a mammalian muscle component and may therefore prove relevant to the pathogenicity of the streptococcus.
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Heart-reactive antibody (HRA) appears in the sera of experimental animals inoculated with group A streptococci as well as patients with acute rheumatic fever. Adsorption of either serum with group A streptococcal membranes will remove the HRA. Blocking experiments between these two types of HRAs have demonstrated that the antibodies are directed towards different antigenic determinants on either the same or different molecules. To isolate and purify the antigen from the group A streptococcus cross-reactive with sarcolemmal sheaths of cardiac myofibers, it became necessary to purify the HRA from rheumatic fever patients' sera. Isolated gamma globulin containing all of the HRA was adsorbed onto human sarcolemmal sheaths. The specific HRA was released by using potassium iodide. Over 99 percent of the purified HRA was shown to bind the sarcolemmal sheath whereas less than 1 percent of the antibody would bind nonspecifically to other material. Preparations of group A streptococcal membrane will bind HRA purified from the sera of acute rheumatic patients at levels of 97 percent or greater. The cross-reactive antigen solubilized by nonionic detergent was purified 120-fold by column chromatography. On sodium dodecyl sulfate polyacrylamide electrophoresis, the antigen was demonstrated to be composed of four polypeptides with mol wt of 32,000, 28,000, 26,000, and 22,000 daltons, respectively. Only proteolytic enzymes could destroy the antigenic determinant whereas glycosidases and lipases had no effect. The purified antigen blocked the binding of purified HRA to normal human heart sections.
Immunoelectrophoresis revealed in phenol extracts from S. faecalis and S. faecium a mixture of free and lipid-bound teichoic acids, both reactive with Group D antisera. In phenol extracts from S. suis only lipid-bound teichoic acid, also reactive with Group D antiserum, was seen. This difference probably accounts for the low yield of Group D antigen from S. suis as compared with S. faecalis and S. faecium when heating at pH 2 is used for extraction. When phenol is used good yields are obtained from S. suis as well as from S. faecalis and S. faecium. Lipoteichoic acids from S. faecalis and S. faecium have a backbone structure the same as or similar to that of Group A streptococcal teichoic acid. Lipoteichoic acid from S. suis has a structure differing from that of S. faecalis and S. faecium, e.g., possibly in the attachment of its glucosyl substituents. Precipitation reactions between S. suis lipoteichoic acid and Group D antisera were specifically inhibited by glucose. Reactions between S. bovis phenol extracts and some Group D antisera were also specifically inhibited by glucose, but extracts from S. faecalis and S. faecium were not. This may indicate a monosaccharide glucosyl substituent in teichoic acid from S. suis and S. bovis instead of the di- or trisaccharide previously postulated as the glucosyl substituent in the teichoic acid of S. faecalis.
The data presented in this paper establish the finding that multiple specific protective antibodies exist in rabbits in response to immunization with Group B streptococci. The summary in Table I indicates the serological types into which Group B streptococci have been divided on the basis of their antigenic composition. This classification is dependent upon passive protection of mice with antibodies directed against the specific antigens, and types are defined in these terms. Heretofore, it was thought that type-specific polysaccharides accounted for all such protection in Group B streptococci. Certain exceptions of cross-protection between types due to minor polysaccharide determinants soon appeared; cross-protection reactions based on protein determinants in at least two types were also discovered. The present experiments show that specific antibodies directed to either polysaccharide or protein antigens of a single strain can be protective against infection with streptococci containing these antigens.
The recent report of 209 cases of septic spontaneous abortion and 11 maternal deaths in the United States in women using the Dalkon Shield intrauterine device (IUD) raised the question about a possible causal relationship between the IUD and pelvic sepsis. It is essential to determine whether or not this sipsis is unique to the Dalkon Shield or generic to all types of IUDs. Our studies permit the conclusion that the tail of the Dalkon Shield is structurally and functionally different from the tails of the four other IUDs tested. The unique characteristics of the Dalkon tail theoretically could provide a mechanism whereby pathogenic bacteria from the vagina enter the uterine cavity and cause sepsis.
A retrospective analysis of all culture-positive cases of Mycobacterium tuberculosis infection in HIV positive individuals, over a 5 year period, revealed 18 cases, drawn from a population of approximately 1500. The prevalence of culture proven M. tuberculosis over the 5 year period was therefore 1.2% and was strongly associated with either a concomitant, or a subsequent, AIDS diagnosis. Sixty-one per cent had pulmonary tuberculosis, 17% had both extra-pulmonary and pulmonary infection and 22% had extra-pulmonary infection alone. Although a wide range of radiological abnormalities was seen, segmental consolidation was the commonest, occurring in 57% of cases. Only 55% of the specimens were positive on initial stains for M. tuberculosis, with a mean duration of 4 weeks to become culture positive, emphasizing that early diagnosis rests on clinical suspicion.
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