Standardization of a preparative ultracentrifuge method for quantitative determination or protein binding of seven antibiotics.

A preparative ultracentrifuge method was standardized for determination of quantitative binding of cephalothin, cefamandole, cefazolin, cefaclor, erythromycin, gentamicin, and chloramphenicol to human serum proteins. At achievable in vivo concentrations, serum binding was 78.5% for cephalothin, 79.9% for cefamandole, 88.5% for cefazolin, 23.5% for cefaclor, 41.9% for erythromycin, 22.7% for gentamicin, and 59.5% for chloramphenicol. Techniques that use semipermeable cellophane or diaflow membranes, cross-linked dextran, inhibition of bacterial growth, protein precipitation, or liquid partitioning all have inherent problems with either the ligand or the antibiotic adversely interacting with the experimental apparatus. Ultracentrifugation provides a rapid, reproducible technique for protein-binding determinations of the classes of antibiotics described.

Evaluation of three newer methods for investigating protein interactions of penicillin G.

THE INTERACTION OF PENICILLIN G WITH HUMAN SERUM PROTEINS WAS EVALUATED BY THREE DIFFERENT TECHNIQUES: rate of dialysis, cross-linked dextran exclusion, and ultracentrifugation. The rate-of-dialysis technique demonstrated that penicillin G binding to serum was immediate but incompletely reversible. Cross-linked dextran adsorbed or trapped significant amounts of penicillin G, necessitating correction factors of more than 10%. Ultracentrifugation was found to be the most reliable method for quantitative protein-binding determinations of penicillins.

Cryoglobulinemia in a patient with Sjögren's syndrome, and factors of cryoprecipitation.

The IgGK cryoglobulin in a patient with Sjögren's syndrome showed deviations from normal IgG involvine its amino acid composition as well as its carbohydrate components. The heavy chains showed abnormal numbers of arginine, threonine, valine and isoleucine residues, and there was an impressive reduction of fucose and hexose components. The carbohydrate deficits appear to be the reason for the incomplete solubility of the isolated IgGK(Ru) at 37 degrees C. with completion at 52 degrees C.

Transient tuberculous meningitis.

Tuberculous meningitis generally is considered to be relentlessly progressive, unless specific therapy is administered. The "aseptic meningitis" of a 56-year-old diabetic patient proved to be tuberculous and regressed spontaneously. Review of the literature shows that spontaneous healing of tuberculous meningitis has been described and demonstrated previously. Awareness of this entity and its recognition are important because this disease may be a focus for subsequent tuberculosis of other organ systems.

Circadian rhythms in polyamine excretion by rats bearing an immunocytoma.

Large-amplitude circadian rhythms were observed in the urinary excretion of polyamines by rats bearing an immunocytoma. Control animals excreted polyamines at a lower rate but also with marked circadian variation. In confirmation of earlier observations, light-chain excretion by the tumor-bearing rats also exhibited a circadian rhythm, superimposed on an increasing trend. The potential of these rhythms as markers for the chronotherapy of cancer is noted.

IgM pyroglobulinemia with erythrocytosis presenting as hyperviscosity syndrome. I. Clinical features and viscometric studies.

The hyperviscosity syndrome is described in a patient with erythrocytosis and an immunoglobulin M with kappa light chain (IgMK) macroglobulinemia. Viscometric studies were carried out on whole blood and demonstrated the contribution of both the increased hematocrit value and the macroglobulinemia to the whole blood viscosity. Clinical improvement followed phlebotomy and was accompanied by a decrease in whole blood viscosity. Continued treatment with chlorambucil has been associated with a long symptom-free period. The macroglobulin was characterized as a monoclonal IgMK pyroglobulin which retained its thermoprecipitability was reduced to 7S monomers. The presence of IgMK aggregates in the serum may have contributed to the increase in blood viscosity.

IgM pyroglobulinemia with erythrocytosis presenting as hyperviscosity syndrome. II. Biochemical properties and mechanisms of pyrogel formation.

An immunoglobulin M with kappa light chains (IgMK) pyroglobulin from a patient with hyperviscosity syndrome, erythrocytosis and coagulation defects has been studied for its immunochemical properties. At physiologic temperatures the purified macropyroglobulin showed a striking tendency to aggregate in the pentamer as well as in the monomer form. This property was also observed in its H chains. Aggregate formation of the pentamers may have contributed to the blood viscosity and coagulation defects. Formation of pyrogel at 56degreesC was observed with pentamers as well as monomers, but not with separated H or L chains. Amino acid analysis showed quantitative abnormalities of aspartic acid, glycine, cystine and leucine within the H chains. Solubility of the pyrogel in sodium dodecyl sulfate, the pyroglobulin's tendency to aggregate and the cystine deficit of H chains implicate conformational changes leading to hydrophobic bonding at 56degreesC in the formation of pyrogel.

Immunologic monitoring and aspergillosis in renal transplant patients.

Three cases of pulmonary aspergillosis in a "high risk" population of renal transplant recipients are presented. The source of infection was traced to the forced air exhaust system of the Transplantation Unit. Early definitive diagnosis of the infection was very important for effective management. Immunologic monitoring was demonstrated to be instrumental in indicating the early presence of infection, and as a guideline to reduced immunosuppression during therapy. Bronchoscopy with brushings and endobronchial cavitary biopsy were valuable methods for obtaining the infected tissue. Amphotericin B was effective when therapy was started early. Adequate levels of the drug were obtained by varying the dose and frequency of administration according to serum inhibitory titers. Control of infection was aided by immunologic monitoring at regular intervals.

Deficiency of secretory Ig-A and intestinal malabsorption.

A patient under treatment with hemodialysis suffered increasing clinical and laboratory evidence of intestinal malabsorption. Jejunal aspirates revealed heavy bacterial and mycotic flora within the proximal jejunum. Secretory Ig-A and secretory component were present only in trace amounts. The deficiency of the generally ubiquitous secretory component is particularaly striking. Oral administration of 20-30 ml. colostrum daily reversed not only the clinical evidence but also laboratory findings of intestinal malabsorption.

Autoimmune phenomena in alcholic cirrhosis.

Serum immunoglobulins usually are increased impressively in alcoholic cirrhosis, particularly IgA and IgM. The basis for these changes has not been clarified. Previous studies with sera of cirrhotic subjects failed to show autoantibody reactions found in other hepatocellular diseases. Two autoantibody reactions were demonstrated by immunofluorescent techniques, using IgG, IgM, and IgA of cirrhotic sera. Purification was achieved by starch block electrophoresis, gel filtration of Sephadex G-200, chromatography on DEAE-Sephadex, and affinity chromatography on columns of Sepharose 4B, in that sequence. IgM appeared as a nonspecific antinuclear antibody, IgA bound to alcoholic hyaline (Mallory bodies). IgG failed to stain any of the examined tissues. It may be the blocking agent which prevents the above-mentioned autoimmune phenomena in whole serum.