PubMed Health⌕ Search

Biomedical subjects

R H McLean

Publications and source records attributed to R H McLean.

At least 73 records · Page 4Linked to original sources
PubMed1980

Partial lipodystrophy and familial C3 deficiency.

A familial deficiency of C3 in the family of a patient with partial lipodystrophy is reported for the first time. This genetic defect is termed hypomorphism of C3 fast (C3f). The defect is detected by analysis of C3 phenotype by densitometry and crossed gel-immunoelectrophoresis; all affected individuals have had reduced serum C3 (lower than 2 SD below mean) on at least one occasion. The possibility that partial lipodystrophy and the frequently associated glomerulonephritis occur in immunologically deficient individuals is supported by this observation.

Complement C3↗
PubMed1980

Activation of the classic complement pathway in patients with the C3 nephritic factor.

5 patients, including 4 with partial lipodystrophy and 1 with dense deposit disease (type II mesangiocapillary glomerulonephritis; MCGN), had positive C3 nephritic factor assays by both a crossed-gel immunoelectrophoretic and a magnesium-dependent hemolytic assay. One or more early classic complement component was significantly decreased in the serum from each patient. The titer of the C3 nephritic factor did not correlate with the presence of dense intramembranous deposits or with the severity of the renal disease. One patient with partial lipodystrophy had ultrastructural evidence suggesting transformation from type I to type II MCGN. These findings do not support a strict separation of MCGN into subtypes according to current criteria.

Adolescent↗
PubMed1979

Preservation of C3, C5, and C5a functional activities by a new radiolabeling method; demonstration of C5 products in complement-activated serum.

A new method is described for the radiolabeling of C3, C5, and C5a. Using a methylation procedure we have labeled C3, C5, and C5a with 14CH20, achieving high specific activity, without loss of hemolytic activity in the case of C3 and C5, and in the case of C5a, full retention of chemotactic and enzyme releasing activities. The distribution of radiolabel in the alpha and beta chains of C5 was 75 and 25%, respectively. Using intact labeled C5 the fragmentation pattern in zymosan-activated human serum, assessed by gel filtration and electrophoresis, is complex, yielding multiple fragmentation products. The labeling method described in this paper yield materials that have many advantages over the currently used labeling procedures.

Autoradiography↗
PubMed1978

Hypomorphic variant of C3, arthritis, and chronic glomerulonephritis.

Decreased synthesis (hypomorphism) of the fast variant of the third component of complement was detected in three generations of a family in which the propositus has an immune complex-type glomerulonephritis, arthritis, and a false positive test for syphilis. An affected sibling has bursitis, hematuria, and proteinuria. Decreased serum C3 protein was detected in three of four and decreased C3H50 in four of four family members with this hypomorphic variant (C3f). This is the first association between C3f and immune complex-type disease.

Adolescent↗
PubMed1976

Recurrence of membranoproliferative glomerulonephritis following kidney transplantation. Serum complement component studies.

Sixteen patients with membranoproliferative glomerulonephritis who required kidney transplantation because of renal failure were evaluated for evidence of recurrence of the original disease by serologic and morphologic studies. Of the 12 patients with transplant tissue available for study, seven showed membranoproliferative glomerulonephritis by light morphology. Four of these seven also had hypocomplementemia, and this hypocomplementemia was characterized by decreased serum CH50, C3 beta1A or C3-C9 but norma serum C1, C4 and C2 by hemolytic assay. Immunofluorescent microscopy demonstrated more intense glomerular deposition of C3 and properdin in the hypocomplementemic patients. Ultrastructural studies demonstrated intramembranous deposits typical of dense deposit disease in one patient who also had marked hypocomplementemia. One patient who had two transplant biopsies and persistent hypocomplementemia showed progression from predominantly mesangial glomerular changes to both capillary wall and mesangial abnormalities. This study has shown a high rate of recurrence of membranoproliferative glomerulonephritis in the transplanted kidneys. A high death rate was noted in persistently hypocomplementemic patients. The serum C profile in hypcomplementemic patients who received translants was similar to that seen before transplantation, but the signficance of this finding remains unknown.

Adolescent↗
PubMed1975

The effect of anticomplementary substances on properdin in normal and C2-deficient sera.

The effect of anticomplementary substances, including zymosan, cobra venom, endotoxin, inulin and immune complexes, on serum properdin concentration and immunoelectrophoretic mobility was studied. In normal serum, zymosan, inulin and immune complexes 'fixed' properdin, while in C2-deficient serum, only zymyosan 'fixed' properdin. Slowly migrating properdin (P) was detected in normal serum following activation by endotoxin and cobra venom but in C2-deficient serum only with cobra venom. Endotoxin did not activate the alternative pathway proteins studied in C2-deficient serum. Fast migrating properdin (P) represented activated properdin and occured as a result of activation of properdin in the Noble agar medium used for electrophoresis provided sufficient cofactors, including Mg2+, were present.

Antigen-Antibody Complex↗