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Biomedical subjects

J Hsu

Publications and source records attributed to J Hsu.

98 records · Page 6Linked to original sources
PubMedDate not supplied

Chronic treatment with dexmedetomidine desensitizes alpha 2-adrenergic signal transduction.

Tolerance to the hypnotic response was induced in rats by chronically infusing dexmedetomidine, a novel alpha 2-adrenergic agonist. The alpha 2-adrenoceptor affinity for dexmedtomidine and para-iodoclonidine was significantly reduced in tolerant rats, while Bmax was uncharged. The ability of pertussis toxin (PTX) to ribosylate guanine nucleotide regulatory proteins (G proteins) ex vivo was reduced in tolerant rats; the quantity of PTX-sensitive G proteins was unchanged. Forskolin-stimulated adenylyl cyclase was less sensitive to inhibition by dexmedetomidine in the tolerant rats; however, acute intraperitoneal injection of dexmedetomidine still reduced cyclic adenosine monophosphate levels in tolerant rats. Both the decrease in ribosylation and the lower alpha 2-adrenoceptor binding affinity may reflect a decrease in the ability of the G protein to couple to the alpha 2-adrenoceptors in the locus coeruleus of tolerant rats. In this state, the alpha 2 adrenoceptors are less capable of transducing the effector response (inhibition of adenylyl cyclase).

Adenylate Cyclase Toxin↗
PubMedDate not supplied

SPLATT combined with tendo achilles lengthening for spastic equinovarus in adults: results and predictors of surgical outcome.

During a 4-year period, split anterior tibial tendon transfer (SPLATT) was performed on 42 adults with cerebrospastic equinovarus deformity. Twenty-one patients (24 feet) had a minimum 1-year follow-up, which included detailed documentation of foot appearance position and function as well as ambulatory status. Thirteen patients were male and 8 were female. Average age of the patients was 41 years. Seventeen patients were independent ambulators with orthoses, one was a maximally assisted ambulator. Three patients with spastic quadriparesis were nonambulatory. All patients had uniform surgical technique and postoperative management. This paper presents the results of SPLATT and identifies risk factors for poor surgical outcomes. After an average follow-up of 39 months, 83% of the feet were rated as having good or excellent results. All ambulatory patients had improved gait and 35% of them were able to discontinue their orthoses. Poor surgical outcomes were associated with nonambulatory status in brain injured patients (P = .018). Salvage of failed SPLATT is discussed.

Achilles Tendon↗
PubMedDate not supplied

Antimicrobial resistance in bacterial chronic sinusitis.

Recent reports describe the emergence of antimicrobial resistant bacteria in acute sinusitis and an increased incidence of enteric gram negative bacilli in chronic sinusitis. The objective of this cross sectional study is to identify the emergent resistance patterns in bacterial chronic sinusitis. Specifically, this article seeks to characterize the bacteriology of outpatient chronic sinusitis, then to compare the antimicrobial susceptibilities of the bacterial isolates with standard culture data from a tertiary care center. Between March and August, 1994, 113 new outpatients presented with chronic sinusitis at a major teaching institution. Of these patients 34 underwent endoscopically guided aerobic culture of the paranasal sinuses and nasal cavities. Of the 48 total cultures, there were 43 positive cultures yielding 72 isolates. Thirty-eight cultures had two or fewer isolates; four cultures had three plus isolates, and one culture grew out normal flora. The most frequently isolated organisms were coagulase negative Staphylococcus (SCN), 20 (28%); Pseudomonas aeruginosa, 12 (17%); and Staphylococcus aureus, 9 (13%). Within the limited sample size for each isolate, Staphylococcus coagulase negative, Pseudomonas, and Pneumococcus demonstrated higher antimicrobial resistance compared to the medical center's corresponding nonurinary isolates. Additionally, three of six patients with Pseudomonal aeruginosa (50%) had a quinolone resistant strain. These preliminary data suggest that both an increased incidence of antimicrobial resistance and of enteric gram negative bacilli may exist in these outpatient, tertiary care center patients with chronic bacterial sinusitis.

Adolescent↗
PubMedDate not supplied

Prolonged ciprofloxacin administration does not accelerate neutrophil recovery after autologous bone marrow transplantation.

STUDY OBJECTIVE: To determine whether prolonged ciprofloxacin administration following autologous bone marrow transplantation (ABMT) accelerates neutrophil recovery. DESIGN: Retrospective analysis of 40 consecutive patients undergoing ABMT. SETTING: Tertiary care bone marrow transplant program. PATIENTS: Two sequential arms of 20 consecutive patients with Hodgkin's disease or non-Hodgkin's lymphoma undergoing ABMT. INTERVENTIONS: The first arm received ciprofloxacin from the day of transplantation until initiation of broad-spectrum antibiotic therapy (median 5 days) while the second arm continued ciprofloxacin until recovery of the neutrophil count (median 15 days). MEASUREMENTS AND MAIN RESULTS: Neutrophil recovery was similar in the two groups (16 vs 14 days; p = 0.41). There were no differences in platelet recovery, bacteremia, or treatment-related mortality. CONCLUSION: Prolonged ciprofloxacin administration does not significantly accelerate neutrophil recovery following ABMT.

Adolescent↗