Biomedical subjects

J Strickler

Publications and source records attributed to J Strickler.

At least 19 recordsLinked to original sources

PubMed2000

Final report of the FOPE II Pediatric Subspecialists of the Future Workgroup.

The report of the Pediatric Subspecialists of the Future Workgroup of the Second Task Force on Pediatric Education reviews the critical changes of the past 2 decades that have affected the provision of pediatric subspecialty services, education of pediatric health care providers, and the acquisition and application of new knowledge. The report considers the future needs that will determine the ability of pediatric subspecialists to meet identified goals. Recommendations for change in the education, role, and financing of the pediatric subspecialist are reported together with those of other workgroups. Pediatrics 2000;106(suppl):1224-1244; pediatric subspecialist, pediatric subspecialist workforce, education pediatric subspecialist, research pediatric subspecialist.

Certification↗

PubMed1999

Clandestine abortion in Latin America: provider perspectives.

This paper presents the results of in-depth interviews with ten clandestine abortion providers in urban Latin America. Three related issues are addressed: how abortion providers come to this line of work; their major difficulties; and their sources of job satisfaction. A variety of paths bring health professionals to the practice of abortion; common elements are a sense of calling, a desire to help women, personal experience with abortion, and a commitment to political change. Providers describe difficulties that include a lack of medical support, the need for secrecy, and threats of violence, extortion, and prosecution. In spite of difficulties, all providers report a great deal of fulfillment in their work, based on their satisfaction in saving women's lives, maintaining supportive relationships with colleagues, and empowering women.

Abortion, Illegal↗

PubMed1998

[Surgical treatment of accommodative convergence access esotropia. Study of 50 operated cases].

BACKGROUND: Convergence excess esotropia (EC) can be an additional component in all forms of strabismus. The most favourable prognosis is found in those cases where EC is associated with microtropia or bifoveal fusion, due to a better binocular potential. METHODS: 50 non selected cases were entered into the study and divided into two groups (Group A: EC with microtropia; Group B: EC with bifoveal fusion). All the patients were followed at the Lausanne Strabismus Unit and all cases underwent a bilateral medial rectus posterior fixation (Cüppers' Faden operation) placed at 13 mm from the original insertion. RESULTS: In Group A, the average reduction of angle of strabismus was 25 delta for near fixation, 20 delta in Group B. In both groups, the average decrease in angle for distance fixation was 6 delta. In Group A, 75% of cases gained some binocularity post-operatively, not only for distance but also for near fixation. In Group B, all the patients showed a normal response on the Lang stereotest post-operatively. CONCLUSIONS: In both groups of this study, a bilateral medial rectus retroequatorial myopexy was a satisfactory alternative for those patients who refused to wear bifocal glasses.

Accommodation, Ocular↗

PubMed1998

bcl-1 gene rearrangements in mantle cell lymphoma: a comprehensive analysis of 118 cases, including B-5-fixed tissue, by polymerase chain reaction and Southern transfer analysis.

We evaluated 118 cases of mantle cell lymphoma by polymerase chain reaction (PCR) for the major translocation cluster (MTC) region and another breakpoint corresponding to probe p94PS, located 24 kb telomeric to the MTC locus on chromosome 11. The specimens included 64 frozen, 19 formalin-fixed, and 9 B-5-fixed lymph nodes and 26 B-5-fixed bone marrow biopsy specimens. We also analyzed DNA from the 64 frozen lymph nodes by Southern transfer analysis (SB) using three separate bcl-1 breakpoint probes. Gene rearrangements were identified in 17 (PCR) and 18 (SB) of 64 frozen lymph nodes and by PCR in 6 of 19 formalin-fixed lymph nodes, 3 of 9 B-5-fixed lymph nodes, and 12 of 26 B-5-fixed bone marrow cores with MTC locus primers and probe. Only one case showed rearrangement with the p11EH probe that corresponds to breakpoints situated 63 kb telomeric to the MTC locus. No rearrangements were detected by PCR or SB for the breakpoint site corresponding to the p94PS probe, but we identified a polymorphic restriction site with HinD III digest in approximately 25% of the cases. In agreement with other studies, these results confirmed that breakpoints in the MTC region of the bcl-1 locus are tightly clustered and associated with 30 to 40% of mantle cell lymphomas. Other breakpoints in the bcl-1 locus seem to be heterogeneous and cannot be detected by PCR or SB with use of existing probes or primer sequences. The most important finding of our study is optimization of the methodology for the detection of immunoglobulin heavy chain gene rearrangement and MTC region breakpoints by PCR from the DNA isolated from B-5-fixed, paraffin-embedded lymph nodes and bone marrow biopsy specimens. The results obtained from these tissues are comparable to those obtained from frozen or formalin-fixed tissue.

Blotting, Southern↗

PubMed1996

Direct preconditioning of cultured chick ventricular myocytes. Novel functions of cardiac adenosine A2a and A3 receptors.

Preconditioning with brief ischemia before a sustained period of ischemia reduces infarct size in the perfused heart. A cultured chick ventricular myocyte model was developed to investigate the role of adenosine receptor subtypes in cardiac preconditioning. Brief hypoxic exposure, termed preconditioning hypoxia, prior to prolonged hypoxia, protected myocytes against injury induced by the prolonged hypoxia. Activation of the adenosine A1 receptor with CCPA or the A3 receptor with C1-IB-MECA can replace preconditioning hypoxia and simulate preconditioning, with a maximal effect at 100 nM. While activation of the A2a receptor by 1 microM CGS21680 could not mimic preconditioning, its stimulation during preconditioning hypoxia, however, attenuated the protection against hypoxia-induced injury. Blockade of A2a receptors with the selective antagonist CSC (1 microM) during preconditioning hypoxia enhanced the protective effect of preconditioning. Nifedipine, which blocked the A2a receptor-mediated calcium entry, abolished the A2a agonist-induced attenuation of preconditioning. Isoproterenol, forskolin, and BayK 8644, which stimulated calcium entry, also attenuated preconditioning. Nifedipine blocked the increase in calcium uptake by these agents as well as their attenuating effect on preconditioning. The present study provides the first evidence that the adenosine A3 receptor is present on ventricular myocytes and can mediate simulation of preconditioning. The data demonstrate, for the first time, that activation of the A2a receptor antagonizes the preconditioning effect of adenosine, with increased calcium entry during the preconditioning stimuli as a novel mechanism.

Animals↗

PubMed1996

[Partly accommodative convergent strabismus with and without excess convergence. Surgical treatment].

BACKGROUND: Partly accommodative esotropia typically shows a persistent convergent angle after correction of hypermetropia. This condition can-or cannot-be accompanied by an accommodative convergence excess. PATIENTS AND METHODS: Fifty patients were examined, operated on and followed up by the same team, and were separated into 2 groups: Group 1: partly accommodative esotropia without convergence excess (N = 20); Group 2: partly accommodative esotropia with convergence excess (N = 30). The operations of the first group consisted of 11 posterior fixations (Fadenoperations) on both internal recti (IR), and 9 combined horizontal operations or recessions of both IR. The operations of group 2 consisted of 23 Fadenoperations and 7 classic procedures. RESULTS: Comparison of angle reductions after a 6-month follow-up showed that posterior fixation was more effective in reducing esotropia when measured without glasses (p = 0.003), whereas both techniques produced similar effects when angles were considered with correction of hypermetropia. In group 2, the effects of posterior fixation on residual angles at near were significantly higher than on angles measured at distance fixation (p < 0.001). Objective refraction (median) was S + 3.60 for group 1 and S + 1.75 for group 2. CONCLUSION: Fadenoperation appeared to satisfactorily reduce convergence excess in our group of 30 patients with partly accommodative esotropia. In our series of 20 patients with accommodative strabismus without convergence excess, Fadenoperation was more effective only when angles were considered without glasses.

Accommodation, Ocular↗

PubMed1995

Factors associated with pregnancy and pregnancy resolution in HIV seropositive women.

This study examines factors associated with pregnancy and pregnancy resolution among 238 HIV-infected women, 55 of whom experienced a recent pregnancy since learning of their HIV positive serostatus. Results suggest the importance of psychosocial and cultural factors, particularly those involving the primary sex partner, to reproductive decision-making in HIV-infected women. They also indicate a consistency of reproductive behavior before and after HIV infection, suggesting that the infection itself does not significantly alter existing childbearing trends. Biomedical considerations relating to the mother's health status and the risk of transmission to the child have a greater impact on decisions surrounding pregnancy resolution than they do on the probability of becoming pregnant.

Abortion, Induced↗

PubMed1995

[Treatment of alphabetic "V" syndromes].

BACKGROUND: Described in the early fifties, V phenomenon remains a controversial subject in respect to its etiopathogeny. Several theories have been proposed dealing to specific surgical treatments. According to the "oblique" theory, we have been performing a bilateral inferior oblique muscle weakening procedure alone or combined with horizontal muscle surgery in our patients presenting horizontal squint associated with a "V" phenomenon. MATERIALS AND METHODS: Since 1984, among the 103 patients presenting with a "V" phenomenon, we have been able to analyze 55 cases (40 "V" esotropias and 15 "V" exotropias) who underwent 3 different surgical protocols; 1) bilateral inferior oblique (IO) muscles weakening procedure combined with conventional horizontal surgery, 2) bilateral IO weakening procedure combined with posterior fixation of Med. Recti (Faden operation) in esotropias only, or 3) bilateral inferior oblique muscles weakening alone. All groups were comparable in respect with there pre-surgical "V" pattern. RESULTS: No statistical significant difference in reduction of the "V" pattern could be demonstrated in the different treatment protocols. "V" esotropias showed a mean 16.3 delta diopter reduction +/- 2.2 SEM in treatment number 1; 19.8 +/- 2.1 in treatment 2. Reduction was only 10.7 +/- 3.3 in group with third treatment. "V" exotropias reduction were: 15.4 delta diopter +/- 1.6 in the combined surgical procedure compared to 18.3 +/- 4.8 in IO weakening alone. No dose-effect relationship could be clearly demonstrated in measured IO weakening procedure. CONCLUSIONS: IO weakening procedure is effective in reducing "V" pattern. This effect is enhanced if associated with an horizontal muscle surgery which reduces the horizontal deviation especially in in V esotropias. We prefer Fink's procedure to simple myotomy since its allows a measurable and reversible IO weakening.

Convergence, Ocular↗

PubMed1994

[Surgical treatment of superior oblique paralysis].

BACKGROUND: Reduction of vertical deviation and ocular torsion are the goals of any surgical treatment of superior oblique palsy. PATIENTS AND METHODS: Our study (n = 70) compares different surgical approaches: Resection (Tuck) of the superior oblique, recession of the inferior oblique, combined operation on both obliques of the involved side, posterior fixation of the inferior rectus on the fellow eye, with or without simultaneous tuck of the paretic superior oblique, Harada-Ito procedure. Reduction of the vertical deviation in different directions of gaze and reduction of cyclotropia in primary position have been compared for each type of operation.

Adolescent↗

PubMed1994

[Superior oblique muscle paralysis and ocular torsion. What is the effect of measuring method on the results?].

BACKGROUND: The rotation of the eye-ball around Fick's Y-axis is called ocular torsion. A precise measurement of the torsional deviation can be clinically as critical in the diagnosis of some complex strabological disorders as in the assessment of some systemic diseases. MATERIALS AND METHODS: We measured the ocular torsion under binocular conditions by five measurement devices on 50 patients with superior oblique palsy. The comparison of the devices was performed using rank tests (Friedman, Wilcoxon signed rank). RESULTS: The 5 methods of measurement do not produce equivalent results. These findings confirm on a population of paretic patients similar published results obtained with healthy subjects. CONCLUSIONS: The simple Maddox rod and the synoptophore are among the most widely used methods to measure cyclotropia; this study reveals that these devices are the least reliable. Harm's tangent scale gives the most reliable results, in all directions of gaze; however, in inferior adduction, the synoptometer also yields a satisfactory measure of ocular torsion. In primary position, the double Maddox glass appears to be the most suitable instrument.

Adolescent↗

PubMed1993

Perceptions of risk for AIDS among women in drug treatment.

In this article factors associated with the self-perceived risk for acquired immunodeficiency syndrome (AIDS) were examined using data obtained from a cross-sectional survey of 155 current and former drug-using women in methadone maintenance. Results suggest that drug-involved women are realistic in their self-perceptions of AIDS risk with respect to intravenous (IV) drug-using behavior but underestimate their risk from sexual activity. Perceived risk was associated with current IV drug use, duration of sexual relationship, and partner's nonsupportiveness. Partner's serostatus or history of IV drug use was unrelated to risk perception, as were multiple partners, anal sex, prostitution, and the nonuse of condoms. Implications of these findings for designing interventions for drug-involved women are considered.

Acquired Immunodeficiency Syndrome↗

PubMed1992

Characterization of the transcription activator protein C1 of bacteriophage P22.

We cloned, expressed, and purified the positive regulatory protein C1 of the temperate phage P22 of Salmonella typhimurium. The purified protein was characterized as to its amino acid composition, protein sequence, molecular weight, and antigenicity. P22 C1 was shown to be a tetrameric protein composed of four identical subunits with M(r) = 10,000. Moreover, we identified and characterized two P22 C1-dependent phage promoters, P(RE) and Pa23, whose function was completely dependent on C1 both in vitro and in vivo. These two promoters share a common TTGCN6TTGC/T motif in their -35 regions, the same motif recognized by the analogous phage lambda transcription activator protein cII. P22 C1 protein bound selectively to this region and centered on the TTGC repeat motif. Binding and transcription experiments demonstrated that the two promoters respond coordinately to C1 activation. Last, in contrast to lambda cII, the C1 protein exhibited little cooperativity with Escherichia coli RNA polymerase for DNA binding, but because of its stronger inherent binding ability, achieved an overall promoter affinity similar to that observed for cII at its cognate promoter signals.

Amino Acid Sequence↗

PubMed1992

The yeast cyclophilin multigene family: purification, cloning and characterization of a new isoform.

Cyclophilins (Cyps) constitute a highly conserved family of proteins present in a wide variety of organisms. Historically, Cyps were first identified by their ability to bind the immunosuppressive agent cyclosporin A (CsA) with high affinity; they later were found to have peptidyl-prolyl cis-trans isomerase (PPIase) activity, which catalyzes the folding of oligopeptides at proline-peptide bonds in vitro and may be important for protein folding in vivo. Cells of Saccharomyces cerevisiae contain at least two distinct Cyp-related PPIases encoded by the genes CYP1 and CYP2. A yeast strain (GL81) containing genomic disruptions of three known yeast PPIase-encoding genes [CYP1, CYP2 and RBP1 (for rapamycin-binding protein); Koltin et al., Mol. Cell. Biol. 11 (1991) 1718-1723] was previously constructed and found to be viable. Soluble fractions of these cells possess residual CsA-sensitive PPIase activity (2-5% of that present in wild-type cells as assayed in vitro). We have purified an approx. 18-kDa protein exhibiting PPIase activity from a soluble fraction of GL81 cells and determined that its N-terminal amino acid (aa) sequence exhibits significant homology (but nonidentity) to the Cyp1 and Cyp2 proteins. We designate the gene for this new protein, CYP3. Using a degenerate oligodeoxyribonucleotide (oligo) based on the N-terminal aa sequence, plus an internal oligo homologous to a conserved region within the portion of CYP1 and CYP2 that had been deleted in the genome, a CYP3-specific DNA fragment was generated by the polymerase chain reaction (PCR) using GL81 genomic DNA as a substrate. This PCR fragment was used as a probe to isolate CYP3 genomic and cDNA clones.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Isomerases↗

PubMed1992

Aspergillus fumigatus sternal wound infections in patients undergoing open heart surgery.

During a 21-month period (July 1986-April 1988), six patients who underwent open heart surgery at Holston Valley Hospital and Medical Center in Kingsport, Tennessee, developed sternal would infections caused by Aspergillus fumigatus. All patients required sternectomy, reconstructive surgery, and long term amphotericin B therapy; no patient died. By univariate analysis, the following were significantly associated with A. fumigatus sternal would infection: chronic lung disease, a recent history of pneumonia, a greater mean number of admission diagnoses, and a particular surgeon. However, multivariate analysis identified chronic lung disease as the only independent risk factor and the best predictor of A. fumigatus sternal wound infections. No factors related to the surgical procedure or operating room personnel were associated with infection. A review of the characteristics of the patients undergoing open heart surgery showed that since 1985, there had been a trend for these patients at Holston Valley Hospital and Medical Center to be older and sicker, which may have contributed to the occurrence of infections never observed before. Despite an extensive investigation, no environmental source for A. fumigatus was identified. A. fumigatus, however, grew from the bronchial washing of one patient at the time the sternal wound infection was diagnosed, and a prospective study showed that the rate of A. fumigatus colonization among open heart surgery patients was the same as the rate of sternal wound infections caused by A. fumigatus. These data suggest that patients with chronic lung disease and respiratory colonization with A. fumigatus are at increased risk for A. fumigatus sternal wound infections after open heart surgery.

Aged↗

PubMed1992

Recombinant human secretory phospholipase A2: purification and characterization of the enzyme for active site studies.

A secreted form of phospholipase A2 (PLA2) is thought to play an important role in inflammatory diseases. To characterize this enzyme the cDNA encoding a low molecular weight PLA2 was cloned from a human placental cDNA library. The cDNA encoding the human PLA2 was subcloned into an expression vector and subsequently transfected into Chinese hamster ovary (CHO) cells. A stable CHO cell clone, secreting ca 1 mg/L of recombinant PLA2 into the medium, was scaled up in culture to 180 L. The recombinant enzyme was purified from the cell supernatant to apparent homogeneity by a novel procedure combining adsorption to poly(vinylidene difluoride) membranes, ion exchange chromatography and size exclusion chromatography. The final recovery of PLA2 activity was 58%. A direct comparison between the purified recombinant human PLA2 and PLA2 purified from human synovial fluid, including molecular weight, antigenicity, ionic dependence, substrate specificity and sensitivity to known PLA2 inhibitors, indicated that the two enzymes exhibit identical biochemical properties. These results show that the recombinant PLA2 can be efficiently expressed and purified in sufficient quantities to characterize the enzyme active site, to aid in the rational development of PLA2 inhibitors as potential anti-inflammatory drugs, and to investigate further the role of PLA2 in inflammatory disease.

Animals↗

PubMed1992

[Comparison of five methods for subjective assessment of ocular cyclodeviation].

METHODS: 1. simple Maddox rod (Franceschetti) 2. set of scaled large diameter Maddox rods 3. synoptophore 4. synoptometer (Cüppers) 5. dark red glass in front of the Harms tangent scale (Kolling). Whereas the first two methods allow to measure in primary position only, the other three also permit secondary and tertiary position measurements. Thirty normal subjects underwent comparative measurements by means of the above techniques in monocular and binocular condition. The median values indicate that all these methods are reliable but that certain specific differences influence the results. For this reason, pre- and postoperative measurements of ocular torsion should always be performed by the same method. The most appropriate techniques have shown to be: the set of scaled Maddox rods for measurements in primary position only, the dark red glass in front of the Harms tangent screen for measuring also in secondary and tertiary positions.

Convergence, Ocular↗

PubMed1991

Structure-function mapping of interleukin 1 precursors. Cleavage leads to a conformational change in the mature protein.

The two interleukin 1 (IL-1) genes (IL-1 alpha and beta) encode 31-kDa precursor molecules, which are cleaved upon secretion to generate the mature, active, carboxyl-terminal 17-kDa proteins. The IL-1 beta precursor is inactive, whereas the IL-1 alpha precursor is as active as the mature IL-1 alpha. In this report, we demonstrate that when either of the recombinant precursors is processed to the mature form, the mature region undergoes a conformational change from a proteinase K-sensitive structure to one that is proteinase K-insensitive. In addition, cysteine residues that are exposed to solvent in the IL-1 beta precursor become buried in the mature protein. Limited structure-activity mapping of the IL-1 beta precursor indicates that the amino-terminal 76 residues are responsible for the conformational change, whereas the most dramatic change in biological activity occurs after further removal of residues 77-94. These findings suggest that the altered structure of the mature region in precursor IL-1s has been conserved for some function. Denaturation/renaturation experiments implicate the precursor domain in protein folding, and by analogy with signal-directed secretory proteins, the unique conformation of the precursors may play a role in IL-1 secretion.

Amino Acid Sequence↗

PubMed1990

Processing of precursor interleukin 1 beta and inflammatory disease.

The processing of precursor interleukin 1 beta (IL1 beta) by elastase, cathepsin G, and collagenase, the major proteases released at sites of inflammation, was investigated using recombinant pro-IL1 beta. Each of these proteases cleaved the 31-kDa inactive precursor to a form similar in size and specific activity (greater than 10(8) units/mg) to the 17-kDa mature protein isolated from activated monocytes. Elastase, collagenase, and cathepsin G cleaved the IL1 beta precursor at distinct sites which are amino-terminal to the monocyte-processing site, Ala-117 (Cameron, P., Lumjuco, G., Rodkey, J., Bennett, C., and Schmidt, J. A. (1985) J. Exp. Med. 162, 790-801). Amino-terminal sequencing of the products of digestion by elastase and cathepsin G determined that resultant active IL1 beta proteins contained an additional 13 or 3 amino acids relative to mature IL1 beta. Synovial fluid collected from patients with inflammatory polyarthritis and bronchoalveolar lavage fluid from patients with sarcoidosis supplied similar processing activity(s). Control fluids from patients who had no symptoms of inflammatory disease did not exhibit processing activity. Lavage fluids that processed precursor IL1 beta were demonstrated to contain cathepsin G and/or elastase activity, whereas controls were negative. Because a significant fraction of IL1 beta may be secreted from monocytes as the inactive 31-kDa precursor (Hazuda, D. J., Lee, J. C., and Young, P. R. (1988) J. Biol. Chem. 263, 8473-8479, Bomford, R., Absull, E., Hughes-Jenkins, C., Simpkin, D., and Schmidt, J. (1987) Immunology 62, 543-549, and Mizel, S. B. (1988) in Cellular and Molecular Aspects of Inflammation Poste, G., and Crooke, S., eds) pp. 75-93, Plenum Publishing Corp., New York), these results suggest that in vivo the IL1 beta precursor can be processed after secretion by any of several proteases released at inflammatory sites.

Amino Acid Sequence↗