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Biomedical subjects

D A Pohl

Publications and source records attributed to D A Pohl.

6 recordsLinked to original sources
PubMed1984

Total colonic aganglionosis initially diagnosed in an adolescent.

A 12-yr-old girl was admitted for evaluation of a 5-wk history of increasing abdominal pain. She also reported a history of constipation since birth requiring chronic laxative use. Occasional bouts of abdominal distention and vomiting resulted in dehydration necessitating hospitalization. Two previous laparotomies had identified an apparent obstructing angulation of the ascending colon. Rectal biopsy specimens obtained on this admission failed to reveal any ganglion cells. Sequential biopsy specimens of the entire colon obtained at laparotomy also failed to reveal any ganglion cells. Ganglion cells were found in the distal ileum. A total colectomy was performed. Three previously reported cases of total colonic aganglionosis initially diagnosed in older patients are reviewed. Similarities included nonspecific radiographic findings, a history of constipation since birth, and initial laparotomies revealing spurious causes of bowel obstruction.

Abdomen↗
PubMed1981

Temperature-sensitive binding of solid phase C1q to aggregated human immunoglobulin G.

The first component of complement (C1q) coupled to Sepharose by cyanogen bromide was found not to bind aggregated human gamma-globulin or immune complexes at room temperature, whereas at 4 degrees C binding was nearly complete. The temperature sensitivity of solid phase C1q binding was reversible. Elution of aggregated human gamma-globulin bound at 42 degrees C was possible by raising the temperature to 23 degrees C. However, free C1q or C1q adsorbed onto polystyrene balls could bind immune complex-like material at both 23 and 4 degrees C. The conformational restraints of C1q covalently coupled to a solid support may not allow functional activity at elevated temperatures.

Chromatography, Affinity↗
PubMed1981

Acute non-A, non-B hepatitis with serum sickness-like syndrome and aplastic anemia.

We treated a patient in whom acute non-A, non-B hepatitis was complicated by a serum sickness-like syndrome (rash, arthralgias). Serum from this patient demonstrated a fall in C3, C4, and total hemolytic complement levels during the syndrome, in association with circulating IgM immune complexes. Fatal aplastic anemia developed later in the patient. This case illustrates that non-A, non-B hepatitis may be complicated by immune complex features that have previously been emphasized to occur with acute hepatitis B. Additional evidence supporting the occurrence of this clinical picture in non-B forms off viral hepatitis is presented.

Acute Disease↗
PubMed1981

Detection of immune complexes using a solid-phase C1q polystyrene ball assay.

A polystyrene ball C1q solid-phase assay (PSB C1q SPA) has been developed for quantitating immune complexes in human serum. While similar to the previously reported solid-phase C1q assays in principle, the use of polystyrene balls with a specular finish has resulted in an assay with significantly improved accuracy, sensitivity and reproducibility. The sensitivity of the assay based on the amount of AHGG bound per microgram C1q added was approximately 12-fold higher in the PSB assay compared to the polystyrene tube solid-phase C1q method. In order to correct for variable background contributions in different samples, values obtained with heat-inactivated C1q were subtracted from each experimental result. Reproducibility studies yielded a coefficient of variation (CV) of 10 and 4% in day-to-day assays using 25 microgram and 100 microgram AHGG/ml normal serum, respectively compared to 11--15% for the tube technique. Within run measurements gave a CV of 37 and 20% at the low and high levels of AHGG. Aggregated human gamma-globulin (AHGG) was used as a model immune complex and when chromatographed on Biogel A-15m yielded major fractions at greater than or equal to 15,000,000 and 150,000 daltons. Maximum binding of AHGG to PSB C1q occurred with aggregates greater than 15,000,000 daltons. Optimum binding of human albumin-anti-albumin complexes in the PSB C1q SPA occurred at a molar ratio of 1 : 1.5. The size distribution of this complex active in the assay determined by sucrose density gradients was 14--32 S with peaks at 21 and 27 S. A normal range of immune complexes was determined as 15 +/- 8 microgram AHGG equivalents (+/- 2 S.D., n = 65). Approximately 70% of rheumatoid arthritis, linear scleroderma, vasculitis, Sjögren's and glomerulonephritis and 40% of SLE patients were above 2 S.D. of normal. SLE patients demonstrated elevations in immune complexes only during periods of increased disease severity. The assay was a useful monitor of plasmapheresis in an SLE patient, showing decreases in immune complexes after each plasmapheresis. DNA did not interfere with AHGG binding whereas lipemia prevented detection of added AHGG.

Antigen-Antibody Complex↗
PubMed1980

Isolation and purification of human C1q from plasma.

C1q was purified to homogeneity from human plasma by a 3-step purification procedure. Plasma was euglobulin precipitated, and the redissolved precipitate chromatographed on a rabbit IgG-Sepharose column. The 1 M NaCl buffer eluate was passed directly through a rabbit anti-human IgG-Sepharose affinity column. C1q freed of IgG was present in the flow through. The rationale for this scheme to remove IgG free and that bound to C1q is discussed. Overall recovery of C1q was about 40% with IgG less than 4 microgram/mg C1q. In SDS-polyacrylamide electrophoresis with non-reducing conditions bands at 52,000 and 42,000 daltons were demonstrated while with reducing conditions bands at 26,000, 24,000 and 20,000 daltons were found as reported by others. C1q was found to be stable at 4 degrees C for 1 year in a 1 M NaCl, 0.4 M Tris, 10% sucrose, 0.005 M EDTA, 0.02% NaN3, pH 8.6 buffer.

Centrifugation↗