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Biomedical subjects

J L Pennaforte

Publications and source records attributed to J L Pennaforte.

31 records · Page 2Linked to original sources
PubMed1992

Peripheral catabolism of CR1 (the C3b receptor, CD35) on erythrocytes from healthy individuals and patients with systemic lupus erythematosus (SLE).

The present study investigated the rate of catabolism of CR1 (the C3b receptor, CD35) on erythrocytes (E) in vivo, in relationship with the expressed number of CR1/E, the CR1.1 HindIII quantitative CR1 polymorphism, and cell age. The relationship between the number of CR1/E and cell age was analysed by measuring G6PDH activity in E that had been sorted according to high or low expression of CR1 (CD35), by assessing the expression of CR1 (CD35) on E separated according to cell density, and by comparing the number of CR1 (CD35) antigenic sites on reticulocytes and on E. A physiological catabolism of CR1 (CD35) manifested by a reduction in the number of CR1 (CD35) antigenic sites/E with cell ageing was consistently observed in healthy individuals. The number of CR1/E decreased with ageing of E according to a complex pattern that associated an exponential decay and an offset. Calculated half-lives of CR1 (CD35) ranged between 11 and 32 days in healthy individuals. A more rapid loss of CR1 (CD35) with cell ageing occurred on cells from individuals expressing high numbers of CR1/E. In patients with systemic lupus erythematosus (SLE), half-lives of CR1 (CD35) on E were in the same range as those of healthy individuals with a similar quantitative CR1 genotype; the number of CR1 (CD35) on reticulocytes was reduced and linearly related to the number of CR1/E, independently of the patients' quantitative CR1 genotype. Transfusion experiments with E bearing high or low amounts of CR1/E indicated the lack of preferential removal of E bearing high numbers of CR1 (CD35) in patients with SLE. These results indicate that the rate of loss of CR1 (CD35) from E with cell ageing is directly related to the quantitative CR1 phenotype and suggest that enhanced peripheral catabolism is not the sole mechanism of the acquired loss of CR1 (CD35) on E in patients with SLE.

Antigens, CD↗
PubMed1992

Increased frequency of the long (S) allotype of CR1 (the C3b/C4b receptor, CD35) in patients with systemic lupus erythematosus.

The allotypic forms of the C3b/C4b receptor (CR1, CD35) differ in length, in the number of expressed C3b binding sites and thus in their ability to mediate the processing of circulating C3- and C4-bearing immune complexes. We have used a combination of three informative restriction fragment length polymorphisms (RFLPs) to assess the frequencies of the F (most frequent allele comprised of four long homologous repeats (LHR)), S (five LHR) and F' (three LHR) alleles of the C3b/C4b receptor (CR1, CD35) in a French population of patients with systemic lupus erythematosus (SLE) (n = 63) and healthy controls (n = 158). A significantly higher frequency of the S phenotype was observed among patients (51%) as compared with controls (26%). The F' allele was found in 2/61 patients and 1/85 healthy controls, indicating the rare occurrence of the short CR1 allele in SLE. This allele is also extremely rare in the normal population. The overrepresentation of the S long allele among patients is indicative of a genetic linkage between CR1 and susceptibility to SLE.

Blotting, Southern↗
PubMed1990

Malignant sacrococcygeal teratoma in an adult.

The authors report the case of a 49-year-old man who had a sacrococcygeal teratoma. Computed tomography showed a mass containing calcification. Digital angiography showed hypervascularization of the lesion. Histologic examination of a transrectal biopsy performed during sigmoidoscopy revealed the lesion to be a malignant teratoma which was not resectable or amenable to treatment.

Adult↗
PubMed1990

Evaluation of the efficacy of prophylactic intravenous antibiotherapy with ceftriaxone in post-chemotherapy agranulocytic patients.

A prospective study was carried out in 44 patients treated by intensive chemotherapy inducing a prolonged neutropenia (granulocytes less than 0.5.10(9)/l). All the patients were isolated in protected rooms, received a pathogen-free diet and nonabsorbable oral antibiotics. After double-blind randomization, 22 patients received 2 g of Ceftriaxone (Cef) in a daily infusion beginning on the first day of chemotherapy; and 22 patients received 2 g of placebo (P) under the same conditions. Prophylaxis was continued until the neutropenia resolved (granulocytes greater than 0.5.10(9)/l) or until the onset of infectious symptoms. 19 patients in each group developed febrile episodes, occurring significantly later in the Cef group (16.6 days versus 10.6 days in the P group). No Cef-resistant organism was isolated. Finally, the time at which apyrexia was obtained after the beginning of curative antibiotherapy was the same in both groups. The routine intravenous administration of Cef in combination with nonabsorbable antibiotics is a useful approach in reducing the risk of infection in the neutropenic host.

Adult↗
PubMedDate not supplied

Monthly intravenous pulse cyclophosphamide therapy in Wegener's granulomatosis.

OBJECTIVE: To study the long term effects of monthly intravenous cyclophosphamide therapy in Wegener's granulomatosis. METHODS: Fourteen consecutive patients with active Wegener's granulomatos treated with a first-line combination of high-dose prednisone and monthly intravenous pulse cyclophosphamide were retrospectively studied. RESULTS: One patient died from septicemia complicating severe leukopenia after the first pulse. At 8 months after instituting intravenous pulse cyclophosphamide therapy, failure was observed in 6 other patients. Between month 16 and 18, 2 other patients relapsed when the time between 2 pulses was lengthened. Five patients developed cyclophosphamide-related side-effects: infection (n = 2), amenorrhea (n = 1), alopecia (n = 2) and vomiting (n = 2). Except for one fatal infection, no major side-effect of intravenous cyclophosphamide therapy was observed. At the end of the study, all patients were off intravenous cyclophosphamide therapy with more than 6 months of followup. The 6 responders were in remission on low-dose prednisone or without treatment. CONCLUSION: A combination of high-dose prednisone and intravenous cyclophosphamide may achieve long-term remission in 42% of patients with Wegener's granulomatosis. Responders to intravenous cyclophosphamide therapy had less extensive disease than non-responders.

Adolescent↗