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Biomedical subjects

A Gewurz

Publications and source records attributed to A Gewurz.

14 recordsLinked to original sources
PubMed1995

Delineation of additional genetic bases for C8 beta deficiency. Prevalence of null alleles and predominance of C-->T transition in their genesis.

We studied the molecular bases for C8 beta deficiency in 34 unrelated families from the United States and the former Soviet Union. These families represented 69 unrelated null alleles of which 59 (86%) were found to be due to a previously described C-->T transition in exon 9. Six additional null alleles were also caused by C-->T transitions, of which four (6%) were located at base 388 in exon 3, one (2%) at base 298 in exon 3, and one (2%) involved cytosine 847 in exon 6. All of the null alleles affecting cytosine 388 were linked to the sequence polymorphism at base 376, which determines the uncommon C8 beta acidic allotype. Two null alleles were caused by single base pair deletions of cytosines at positions 430 and 632 in exons 3 and 5, respectively. Of the characterized null alleles, 97% were due to C-->T transitions in which an arginine (64 alleles) or a glutamine (one allele) was replaced by a stop codon. The basis for this apparent high frequency of C-->T transitions occurring in a relatively short stretch of DNA is uncertain.

Alleles↗
PubMed1993

Complement factor I deficiency with recurrent aseptic meningitis.

Patients with deficiency of the complement regulatory protein factor I typically present with systemic pyogenic bacterial infections, including meningitis. We report a novel case with total deficiency of factor I in serum and plasma; the patient experienced nine consecutive episodes of aseptic meningitis within a 2-year period. There was no history of previous bacterial sepsis. Aseptic meningitis recurred despite attempted penicillin prophylaxis. Each episode resolved rapidly without sequelae, with or without antibiotic treatment. Serum complement profiles showed persistently low levels of C3, factor B, and factor H and undetectable factor I protein. Family complement studies could not be performed. Except for a minimally increased titer of antinuclear antibody, no other immunologic abnormality was detected. Results of an oral ibuprofen challenge were negative. We conclude that deficiency of factor I may predispose to aseptic, as well as pyogenic bacterial, meningitis.

Adult↗
PubMed1991

Association of cigarette smoking with elevated serum IgE levels in Hispanic Puerto Rican men.

Unexplained elevation of serum IgE concentrations occurs in cigarette-smoking Caucasian males from temperate zones. To determine whether race or geography might be factors, we measured serum IgE concentrations in 94 Puerto Rican Hispanic patients, including smokers and nonsmokers. Mean serum IgE levels were elevated in our total patient population compared with Caucasian Americans. Geometric mean IgE was significantly increased in total smokers (157 IU/mL) compared with nonsmokers (78 IU/mL) and in male smokers greater than age 55 years (335 IU/mL) compared with male nonsmokers (41 IU/mL). Serum IgE was not significantly increased in female smokers. Among patients older than 55 years, persistent elevation of serum IgE occurred in male smokers. Our findings in a Puerto Rican Hispanic population are similar to those in studies of Caucasian smokers in temperate zones.

Adolescent↗
PubMed1988

Inherited C3 deficiency with recurrent infections and glomerulonephritis.

A 10-year-old Laotian boy had homozygous deficiency of the third component of complement and recurrent bacterial infections beginning at age 5 months. Cellular and humoral immunity were normal, as were polymorphonuclear leukocyte chemotaxis and bactericidal activities. Serum complement-mediated hemolytic, chemotactic, and opsonic activities were deficient. In vitro addition of purified C3 to patient serum restored hemolytic complement to normal levels, and plasma infusion during each of four episodes of pneumonia significantly enhanced serum opsonic activity for as long as 36 hours. A renal biopsy specimen revealed mesangiopathic glomerulonephritis, although significant levels of circulating IgG immune complexes were not detected. These findings further support the association of C3 deficiency with immune-complex disease and suggest that plasma infusion may be an adjunct to antibiotic therapy in the management of severe pyogenic infections in patients with C3 deficiency.

Bacterial Infections↗
PubMed1986

Soluble copolymer of wasp venom with human albumin for venom immunotherapy.

Polymerization of allergens decreases allergenicity while retaining immunogenicity, as we have demonstrated for ragweed, grass, and tree pollens. We have also polymerized bee venom with human albumin to form soluble, high-molecular-weight copolymers that are immunogenic in rabbits. We now have prepared a soluble wasp venom-albumin polymer (WVAP), molecular weight greater than or equal to 240,000 daltons, by glutaraldehyde treatment and Sephacryl S-300 column fractionation. Rabbits immunized with WVAP produced IgG to both WVAP and wasp venom (WV), as measured by ELISA. IgG against WVAP was totally inhibitable by a mixture of WV and albumin, demonstrating both retention of native antigens and absence of new antigenic determinants in WVAP. IgG against WV in serum from patients receiving maintenance doses of WV immunotherapy was inhibited by WVAP. In summary, we have synthesized a soluble, high-molecular-weight copolymer of WV that retains the immunogenicity of native WV, contains no new antigenic determinants, and has potential value in the treatment of patients with WV anaphylaxis.

Animals↗
PubMed1984

Recurrent sepsis with deficiencies of C2 and galactokinase.

A 4-year-old girl with recurrent, severe bacterial infections and absence of both the second component of complement and galactokinase was investigated for immunodeficiency. The C2 deficiency (C2D) was diagnosed after four major pyogenic infections. Results of studies of cellular and humoral immunity were normal, as were polymorphonuclear leukocyte chemotaxis and bactericidal activities and alternative-pathway hemolytic activity. Serum chemotactic and opsonic activities were deficient in this patient and in an older, asymptomatic sibling with C2D. Fresh-frozen plasma, administered during an episode of Streptococcus pneumoniae meningitis, enhanced serum opsonic activity at 12 hours after infusion. To our knowledge, this is the first description of C2D in a patient with a documented second, unusual genetic defect.

Antibody Formation↗
PubMed1983

Absence of the seventh component of complement in a patient with chronic meningococcemia presenting as vasculitis.

A previously healthy 40-year-old man presenting with fever, arthritis, and cutaneous vasculitis was found to have chronic meningococcemia. Evaluation of his complement system showed an absence of functional and antigenic C7, compatible with a complete deficiency of the seventh component of complement. Study of the patient's family spanning four generations showed heterozygous deficiency of C7 in five members. Chronic neisserial infection can be associated with C7 deficiency and must be distinguished from other causes of cutaneous vasculitis.

Adult↗
PubMed1981

Renal transplantation in a patient with hereditary deficiency of the second component of complement.

The HLA haplotype A 10,B18 has been associated with hereditary deficiency of the second component of complement(C2). In an effort to detect individuals homozygous for C2 deficiency, a thorough audit of HLA serotyping results in 3,100 individuals was performed, and a single patient homozygous for the A10, B18 haplotype was identified. Detailed complement studies in this patient's serum and plasma revealed previously undetected selective absence of C2 antigen and haemolytic activity, and a hereditary basis for this deficiency was indicated by half-normal levels of C2 haemolytic activity in both of his children. The patient was of special interest in that he had previously developed renal failure which was treated by cadaver kidney transplantation. C2 antigen was undetectable in serum and plasma samples taken prior to and up to 9 months following transplantation. This experience suggests that HLA serotyping can be a valuable screening technique for the detection of individuals with C2 deficiency, and that renal transplantation does not reconstitute normal levels of C2.

Adult↗
PubMed1976

Absence of the sixth component of complement in a patient with repeated episodes of meningococcal meningitis.

A previously healthy 6-year-old boy who presented with meningococcal meningitis responded favorably to ampicillin, but suffered two and possibly three repeat attacks in the ensuing month. No abnormality of the otolarynx, skin, or neuroskeleton was found. The infecting strain, Neisseria meningitidis, Group Y, Type IV, was sensitive to the therapeutic agents used, and antibiotic levels were adequate. Serum bactericidal antibody titers against autologous meningococci were high. Serum complement hemolytic bactericidal activities, however, were entirely lacking, and this was attributable to a complete deficiency of C6. Measurements of the remaining complement components, C-dependent chemotaxis and opsonization, neutrophil function, specific immunity, and the coagulation system, were normal. The parents had half-normal C6 levels. Recurrence of meningitis in this patient supports the concept that complement plays a role in resistance to certain microorganisms and emphasizes the need for complete evaluation of the complement system in individuals with unexplained repeated infections.

Child↗
PubMed1976

Purification of cobra venom factor from phospholipase A contaminant.

It has been demonstrated that cobra venom factor prepared by the usual combination of ion exchange chromatography and sephadex gel filtration is contaminated by substantial amounts of a 'heavy' phospholipase A. The two activities may be separated by isoelectric focusing. Cobra venom factor focuses at pH between 5-75 and 6-75 whereas the phospholipase is all found at pH below 7-75. In certain test systems, particularly in vitro, and particularly where albumin concentrations are low, the contaminating phospholipase may produce effects that have been attributed to complement activation.

Chromatography, Gel↗
PubMedDate not supplied

Soluble copolymers of yellow jacket, yellow hornet and white faced hornet with human albumin for venom immunotherapy.

Soluble polymers have been prepared by polymerizing human serum albumin (HSA) with either yellow jacket venom (YJV), yellow hornet venom (YHV) or white faced hornet venom (WFHV). The venom-albumin polymer preparations were fractionated on Sephacryl S-300 to have a molecular weight range higher than catalase (2.4 x 10(5) daltons). Rabbits were immunized with either yellow jacket venom-albumin polymer (YJVAP), yellow hornet venom-albumin polymer (YHVAP) or white faced hornet venom-albumin polymer (WFHVAP). Rabbits immunized with venom-albumin polymer (VAP) produced IgG antibody to VAP and venom, as measured by enzyme-linked immunosorbent assay (ELISA). Experiments to demonstrate antigenic completeness and absence of new antigenic determinants in the polymer were performed using WFHVAP. IgG against WFHVAP was completely inhibited by a mixture of WFHV and HSA demonstrating the absence of new antigenic determinants in WFHVAP. IgG against WFHV in sera from patients receiving maintenance doses of WFHV immunotherapy was completely inhibited by WFHVAP, demonstrating antigenic completeness. We have previously described similar results with bee venom-albumin polymer and wasp venom-albumin polymer. We now conclude that VAP preparations of all five clinically relevant hymenoptera venoms have potential value in the treatment of hymenoptera anaphylaxis.

Animals↗