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Biomedical subjects

J Shannon

Publications and source records attributed to J Shannon.

17 recordsLinked to original sources
PubMed1995

Molecular cloning of a major cockroach (Blattella germanica) allergen, Bla g 2. Sequence homology to the aspartic proteases.

Inhalation of allergens produced by the German cockroach (Blattella germanica) elicits IgE antibody formation and the development of asthma in genetically predisposed individuals. We compared the allergenic importance of two cockroach (CR) allergens, Bla g 1 and Bla g 2, and determined the complete amino acid sequence of the major 36-kDa allergen, Bla g2. A survey of 106 sera from CR allergic patients showed the prevalence of IgE antibodies to Bla g 1 and Bla g 2 to be 30.2% and 57.6%, respectively. Immediate skin tests on 7 selected patients gave positive reactions using 10(-3) micrograms/ml either allergen, whereas controls showed no response to 10 micrograms/ml. Natural Bla g 2 was purified and the sequence of the NH2 terminus and tryptic peptides, comprising 36% of the molecule, was determined. The cDNA for Bla g 2 was cloned from a B. germanica expression library and encoded a 24-amino acid signal peptide and a 328-amino acid mature protein, which showed the highest degree of identity to mosquito (Aedes aegypti) lysosomal aspartic protease (30.8%), with similar identity to pepsin, cathepsins D and E, renin, and chymosin. Bla g 2 mRNA and protein were detected in B. germanica, but not in Periplaneta americana, the other principal domiciliary CR species in the U.S. High concentrations of Bla g 2 were found in CR digestive organs (esophagus, gut, and proventriculus). The results show that Bla g 2 is a major species-specific allergen of B. germanica and suggest that the allergen functions as a digestive enzyme in the cockroach.

Allergens↗
PubMed1995

Cocaine abuse in methadone maintenance patients is associated with low serum methadone concentrations.

Cocaine abuse in methadone maintenance patients has emerged as a significant clinical problem. To determine if raising the daily methadone dosage is an effective way to eliminate cocaine abuse, 74 methadone maintenance patients maintained at daily dosages between 30 and 80 mg and who chronically abused cocaine were studied by a standard protocol. A total of 21 (28.4%) subjects ceased cocaine abuse when their methadone dosage was progressively raised to a maximal daily dose of 160 mg. Cocaine abuse appeared to accelerate elimination of methadone, since inadequate methadone serum concentrations (below 100 ng/ml) were found in 48 of 67 (71.6%) subjects tested 24 hours after a 100 mg oral methadone dose. Although cocaine abuse in methadone maintenance patients may respond to raising the daily methadone dosage, alternative treatments for cocaine abuse in methadone maintenance patients must be identified since cocaine abuse may lower serum methadone concentrations.

Adult↗
PubMed1994

Role of infused CD8+ cells in the induction of peripheral tolerance.

The CD8 molecule when present on a cell recognized by a mature T cell has been shown to have an inhibitory effect on the development of an in vitro immune response by that T cell. To test whether CD8 has a role in the induction of peripheral tolerance in vivo, we have studied tolerance induction in B6 female mice carrying a transgenic TCR specific to male H-Y Ag. Previous studies have shown that male Ag reactive cells are inactivated in these mice after the i.v. injection of viable male lymphoid cells. Here, B6 female transgenic mice were injected with B6 male lymph node cells from CD4 or CD8 gene knockout mice, and the fate of male Ag-specific T cells was followed in vivo. Our results indicate that injection of male CD4 knockout (express CD8) lymphoid cells but not CD8 knockout (do not express CD8) lymphoid cells induced a significant reduction of male H-Y Ag reactive cells in the periphery, suggesting that CD8 plays an important role in the induction of peripheral tolerance of class I-restricted T cells. These results imply that peripheral tolerance can be induced not just by absence of signals required for activation but by the presence of additional signals.

Animals↗
PubMed1992

Purification and microsequencing of the intra-acrosomal protein SP-10. Evidence that SP-10 heterogeneity results from endoproteolytic processes.

The human sperm antigen SP-10 has been shown to be a testis-specific, intra-acrosomal protein that is associated with the membranes and matrix of the acrosomal vesicle. Sperm extracts, analyzed on Western blots with a monoclonal antibody to SP-10, have shown heterogeneity of SP-10 peptides ranging from 17.5-34 kDa. Although the entire SP-10 amino acid sequence of 265 amino acids (28.3 kDa) has been deduced from sequencing SP-10 cDNAs, the nature of multiple SP-10 peptide bands is incompletely understood. In this study, we developed a three-step purification method for SP-10 peptides using monoclonal antibody affinity chromatography, reverse-phase HPLC, and preparative gel electrophoresis. Eight SP-10 peptides separated by this protocol and sequenced using Edman degradation showed amino termini that corresponded to regions on the deduced SP-10 amino acid sequence. Peptides with progressively lower apparent mass aligned further toward the carboxy terminus. On the basis of putative cleavage sites on the SP-10 sequence, endoproteases that act at five different peptide bonds are predicted to cleave SP-10: these hydrolyze following arginine (a trypsin-like protease, possibly acrosin), and following serine, proline, glycine, and glutamic acid (previously undescribed intra-acrosomal protease specificities). The present studies 1) provide a purification method for SP-10 peptides; 2) confirm that the SP-10 cDNAs previously sequenced encode authentic SP-10; and 3) yield indirect evidence that endoproteases act to contribute to SP-10 heterogeneity.

Acrosome↗
PubMed1991

Epidemiology of pelvic inflammatory disease at University Medical Center, Jacksonville.

Patients hospitalized with acute pelvic inflammatory disease at University Medical Center of Jacksonville had a mean age of 26.8 years. Contraception use was minimal and mean gravidity was two. Hospitalized patients had a high incidence of peritonitis and tubo-ovarian abscess. N. gonorrhoeae was cultured in 50%. Mean temperature on admission was 100.5 degrees and mean white blood cell count 15,400. Mean hospitalization was 5.5 days. Two of nine patients tested for HIV were positive (22% of those tested, 2% of all patients reviewed).

Abscess↗
PubMed1989

Quantitative urine testing. A new tool for diagnosing and treating cocaine use.

The new quantitative urine tests for cocaine are an easy and inexpensive method of diagnosing and monitoring use of this drug and thus are practical for the primary care physician's office. They may help differentiate between occasional and addicted users, thus establishing the severity of the problem for the patient and family, employer, or school officials. Although the tests cannot be used for legal applications, they have great clinical value. The receptivity of patients and third parties to urine testing has been gratifying. Physicians are encouraged to consider use of these tests in office assessment.

Adolescent↗
PubMed1988

Rat pulmonary surfactant protein A is expressed as two differently sized mRNA species which arise from differential polyadenylation of one transcript.

In rat, the surfactant-associated glycoprotein A, SP-A, is encoded by two mRNA species of 0.9 and 1.6 kb. Each transcript is polyadenylated and is found in approximately the same ratio in total cellular RNA isolated from either alveolar type II cells or from whole lung. The two mRNA species have identical coding regions and differ only in the length of the 3' untranslated sequences. Restriction analysis and partial sequence analysis of rat genomic clones indicate that each mRNA species arises from one gene, with the difference in size most easily accounted for by differential polyadenylation. During fetal development, the accumulation of mRNA encoding SP-A is detectable by day 18 but increases many-fold on day 19. However, there are no apparent alterations in the prevalence of either mRNA species during fetal development or in the early postnatal period.

Amino Acid Sequence↗
PubMed1988

Thoracic outlet syndrome: a comprehensive evaluation.

Using various modalities, 480 patients were evaluated for thoracic outlet compression syndrome. Of this group, 300 patients were eventually diagnosed as having thoracic outlet syndrome after extensive evaluation. Ninety of these patients underwent a total of 103 operative procedures for thoracic outlet decompression. Nerve conduction velocities and directional Doppler studies were the most useful adjuncts in making the diagnosis. Surgical therapy after proper selection yielded an 80.6 per cent long-term "good" operative result and an additional 6.9 per cent long-term "fair" operative result in follow-up to 12 years.

Adult↗
PubMed1987

Intraoperative autologous transfusion during major aortic reconstructive procedures.

To evaluate the benefits and disadvantages of autologous intraoperative transfusion during major aortic reconstructive procedures, we retrospectively studied 50 patients who had major aortic revascularization procedures without the use of autologous transfusion devices (group 1) and prospectively evaluated a second 50-patient cohort having similar procedures, but with the use of the autologous transfusion device for salvaging and reinfusing lost blood. Both groups were assessed for preoperative risk factors and postoperative complications. We found a somewhat lower morbidity in the autotransfusion group and more complete replacement of blood loss. Autologous transfusion accounted for approximately 75% of all transfused blood in group 2, tremendously reducing blood bank requirements. In addition to reduction of immediate postoperative morbidity, further risks associated with homologous transfusion such as hemolysis, posttransfusion hepatitis, transfusion-related acute lung injury, anaphylaxis, and transfusion-transmitted acquired immunodeficiency syndrome (AIDS) were markedly reduced or eliminated.

Aged↗
PubMed1980

Malaria in southeast Queensland in 1979.

The incidence of malaria in Australia is increasing. With the emergence of strains of Plasmodium falciparum resistant to chloroquine there are new lessons to be learned by laboratory workers in the species diagnosis; by clinicians in the clinical manifestations, the treatment of prophylaxis; and by members of the public about the dangers of malaria, and how it can be prevented. At the same time, old knowledge must not be forgotten. This paper reports some recent experience with a sizeable number of cases.

Adolescent↗
PubMed1980

Atherosclerotic coarctation of the abdominal aorta in women.

In the ten year interval from 1967 to 1976, in a group of 200 patients with aortoiliac occlusive disease, six were identified who presented a unique combination of physical findings, angiographic abnormalities and pathologic changes. Atherosclerotic coarctation describes this entity because of the discreteness of the lesion found, the extent to which the aorta is occluded and the presence of extensive collaterals. Pathologically, the lesion is an organized thrombus forming on a single ulcerated plaque in an aorta with a lumen that is otherwise well preserved. Distally, infantile vessels are found. Other features have been the absence of diabetes mellitus and the fact that all of these patients have been women. All but one patient smoked cigarettes. Local endarterectomy restored pedal pulses and provided lasting relief of symptoms in all of the patients.

Aged↗
PubMedDate not supplied

Lateral femoral cutaneous nerve block revisited. A nerve stimulator technique.

BACKGROUND AND OBJECTIVES: Regional block of the lateral femoral cutaneous nerve (LFCN) often has disappointing success rates despite the large volumes of local anesthetic used. This study was undertaken to investigate the utility of using a nerve stimulator (NS) to localize and block the LFCN. METHODS: After obtaining institutional approval and informed consent, the authors proceeded with a two-stage study. In stage 1, 20 ASA 1 volunteers underwent LFCN block by both a fan and a NS technique in a prospective, randomized, crossover study utilizing strict criteria for success and extent of block. To predict clinical utility, 20 patients underwent LFCN block by the NS technique using the same assessment criteria (stage 2). Statistical analysis for the comparisons was completed employing the Fisher's exact or paired t-test as appropriate. P < .05 was considered significant. RESULTS: The NS technique significantly improved the success of LFCN block over the fan technique (100% vs. 40%, P = .00002). The extent of successful blocks was no different with the two techniques. Success in stage 2 was similar to that in stage 1 (85%) predicting clinical utility. CONCLUSIONS: A NS can be used to localize a purely sensory nerve; such as the LFCN, and improve success rates in regional anesthesia.

Adult↗