Biomedical subjects
J McClure
Publications and source records attributed to J McClure.
The chemistry and biology of thymosin. I. Isolation, characterization, and biological activities of thymosin alpha1 and polypeptide beta1 from calf thymus.
A partially purified extract from thymus tissue termed thymosin Fraction 5 has been shown to reconstitute immunological deficiencies resulting from the lack of thymic function in several animal models, as well as humans with primary and secondary immunodeficiency diseases. Thymosin Fraction 5 consists of a family of polypeptides with molecular weights ranging from 1,000 to 15,000. Several of these polypeptides contribute individually to the biological activity of the parent compound. Two polypeptide components of thymosin Fraction 5, termed thymosin alpha1 and polypeptide beta1, have been characterized chemically and biologically. Thymosin alpha1 is a highly acidic molecule composed of 28 amino acid residues. This polypeptide has potent biological activity and has been found to be 10 to 1,000 times as active as thymosin Fraction 5 in one in vivo and several in vitro bioassay systems designed to measure differentiation and function of thymus-dependent lymphocytes (T cells). Polypeptide beta1, in contrast, is inactive in our bioassay systems, suggesting that it is not involved in thymic hormone action. Sequence analysis and homology studies have indicated that polypeptide beta1, although present in Fraction 5, does not contribute to the biological activity of thymosin Fraction 5.
A comparison of the inhibitory effects of disodium pyrophosphate and disodium ethane-hydroxy-1, 1-diphosphonate on simple calcergy.
Both disodium pyrophosphate and disodium ethane-hydroxy-1, 1-diphosphate inhibit the reaction of simple calcergy induced in the mouse by lead acetate. The pyrophosphate is effective only by a direct interaction with the lead salt and the disphosphonate is effective only before the occurrence of histochemically demonstrable calcification.
Detection of thymosin in thymic epithelial cells by an immunoperoxidase method.
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Presence of thymosin-like factors in human thymic epithelium conditioned medium.
The objective of the present study was to determine whether or not thymosin and conditioned medium from human thymus epithelial cultures (HTECM) contain similar fractions, capable of inducing T-cell differentiation. Therefore we tested the ability of rabbit antisera to different thymosin fractions (thymosin fractions 5, 6 and alpha 1) of both bovine and human origin to block the stimulatory effect of HTECM on Con A and PHA response of mouse thymocytes. We also looked for reactivity of the antisera toward tissues of man, mouse and calf, and to tissue cultures of man and mouse. Anti-thymosin fraction 5 and 6, but not anti-thymosin-alpha 1, were found to inhibit the stimulatory effect of HTECM on both Con A and PHA responses. This cannot be attributed to cytostatic or cytotoxic effects of the antisera on thymocytes. No effect was seen when using antiserum to kidney fraction 5 or normal rabbit serum. In both tissue sections and tissue cultures of the different species tested, anti-thymosin reacts only with thymus epithelial cells. The reactivity is blocked by neutralizing the antisera with thymosin fraction 5 but not by kidney fraction 5. The reactivity is also strongly diminished by neutralizing the antisera with HTECM but not with supernatants of conditioned media from non-thymic tissues. The observations are highly suggestive for the presence of similar fractions in HTECM and thymosin, and that both are secreted by thymus epithelial cells.
A case of urethral malacoplakia associated with vesical disease.
A case of recurrent urethral malacoplakia with coexisting disease of the bladder is described. This is compared to the single previously reported case of involvement of this site.
Titin: major myofibrillar components of striated muscle.
Electrophoretic analyses of protein components of striated muscle myofibril purified from various vertebrate and invertebrate species revealed that proteins much larger than myosin heavy chain are present in significant amounts. To define possible roles of these heretofore unidentified proteins, we purified a combination of two uncommonly large proteins, designated as titin, from chicken breast myofibrils. Chemical and immunological studies indicated that titin is distinct from myosin, actin, and filamin. Specific titin anti body crossreacts with similar protein in both skeletal and cardiac myofibrils of many vertebrate and invertebrate species. Immunofluorescent staining of glycerinated chicken breast myofibrils indicated that titin is present in M lines, Z lines, the junctions of A and I bands, and perhaps throughout the entire A bands. Similar staining studies of myofibrils from other species suggest that titinlike proteins may be organized in all myofibrils according to a common architectural plan. We conclude that titin is a structurally conserved myofibrillar component of vertebrate and invertebrate striated muscles.
Malakoplakia of the prostate: a report of two cases and a review of the literature.
Two cases of malakoplakia of the prostate are documented, bringing the total described in the world literature to 15. This literature is reviewed, and typical features of the condition are established. The majority of the cases have had proven previous episodes of Escherichia coli infection of the urinary tract, but bacilliform organisms have yet to be demonstrated in the diseased prostatic tissue. Five of the reported cases have also had important additional disease, including three instances of malignant lung tumour. Finally, it is emphasised that recognition of prostatic malakoplakia as an entity will prevent its confusion with prostatic carcinoma.
An evaluation of elementary students' voluntary physical activity during recess.
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LDH isoenzyme pattern in a meningioma with pulmonary metastases.
The case is presented of an intraspinal meningioma in a 14-yr-old female. After surgical exploration pulmonary metastases became apparent. At necropsy the tumour had increased proportions of the cathodal isoenzymes LDH-4 and 5. This pattern has previously been observed in malignant meningiomas and may be used at the time of biopsy to assess malignancy.
Thymosin alpha1: isolation and sequence analysis of an immunologically active thymic polypeptide.
The amino acid sequence of a biologically active polypeptide isolated from calf thymus, termed thymosin alpha1, has been determined. Thymosin alpha1 is a heat stable, highly acidic molecule composed of 28 amino acid residues. This peptide is one of several present in thymosin fraction 5 that may participate in the regulation, differentiation and function of thymus-dependent lymphocytes (T cells). A nomenclature for the family of polypeptides present in thymosin fraction 5 is suggested.
Adrenocortical hyperactivity with disseminated malacoplakia.
A case is described of an ectopic ACTH syndrome associated with malacoplakia.
Vestibular dysfunction associated with benign paroxysmal vertigo.
Benign paroxysmal vertigo (BPV) is a clinical syndrome of vestibular origin although generally no evidence of vestibular dysfunction can be demonstrated with conventional tests. In a review of 1350 consecutive dizzy patients, there were 125 with BPV and of these, 33 underwent a quantitative rotational test of vestibular function. The rotational results showed reduces vestibular system gain for these BPV patients. In addition, they could be subdivided on the basis of a normal or shorter cupular time constant (Tc). Separation of patients into diagnostic categories revealed that those categorized as cupulolithiasis and viral labyrinthitis had a normal Tc range and those categorized as trauma and idiopathic had a short Tc. The reduced gain and short Tc in the latter group suggest hair cell and/or nerve damage since these same changes occur in patients with destructive peripheral vestibular disease.
The production of calcification in connective tissue and skeletal muscle using various chemical compounds.
The subcutaneous injection into mice of small quantities of lead salts resulted in calcification of the dorsal fascia. Other reputed calcergens failed to produce a similar reaction. However, the injection of Zn Cl2 and KMn O4 in high doses caused damage to, and subsequent calcification of the panniculus carnosus muscle.