Genetic diversity among Mycobacterium avium complex strains recovered from children with and without human immunodeficiency virus infection

The genetic diversity and molecular epidemiology of Mycobacterium avium complex (MAC) infections in children with and without human immunodeficiency virus (HIV) infection were evaluated. Isolates recovered from 136 children were subtyped by sequence analysis of a 360-bp region of the gene (hsp65) encoding a 65-kDa heat-shock protein. Twenty-one distinct hsp65 alleles were identified. On the basis of hsp65 genotype, 6 isolates were not MAC organisms. Of the remaining 130 samples, 61% were M. avium, 37% were Mycobacterium intracellulare, and 2% were species nonspecific MAC. Eighty-eight percent of the isolates obtained from HIV-infected children were M. avium. In contrast, only 38% of the isolates obtained from children without HIV infection were M. avium (chi2 test, P < .001). M. avium isolates were further subtyped by Southern blot analysis with insertion element IS1245. Taken together, no evidence for a single clonal M. avium strain causing infection was detected.     

Gelatinase B and A expression after laser in situ keratomileusis and photorefractive keratectomy

OBJECTIVE: To compare the expression of gelatinases in the corneal epithelium and stroma after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). METHODS: Rabbit eyes were treated with LASIK (n=11), PRK (n=12), or corneal flap construction (n=12); 4 eyes served as unwounded controls. Zymography was performed on the central epithelium and the stroma 1, 3, and 7 days after surgery to determine the expression of gelatinases. RESULTS: Epithelial expression of gelatinase B in the LASIK group (0%-25%) was lower than that in the PRK group at all time points (50%-100%) and was identical to the corneal flap group. Stromal expression of gelatinases A and B was similar after LASIK and PRK, but was minimal after corneal flap construction at all time points. Epithelial expression of gelatinase A was similar for the first 3 days after LASIK and PRK but not thereafter. CONCLUSIONS: Gelatinase B epithelial expression was up-regulated after PRK but not after LASIK. Gelatinase B stromal expression was up-regulated after both procedures. CLINICAL RELEVANCE: Differences in wound healing and subepithelial scarring after these 2 procedures may be related to gelatinase B.     

Synthesis and conformational analysis of a novel type of spin labelled bicyclonucleoside based on a tetrahydrofurano[2,3-c]pyrrolidine sugar skeleton

Bicyclonucleosides bearing a 5-deoxy-5-N-hydroxyamino-3,N5-(1,1-ethano)-beta-D-furanosyl sugar moiety (15-18) have been prepared by glycosidation of the corresponding bicyclosugars obtained via an intramolecular reverse Cope elimination. The configuration of the asymmetric carbon of the 1,1-ethano bridge is the most important factor directing the conformation of the N-hydroxypyrrolidine ring and its invertomers ratio as shown by variable temperature H NMR experiments.     

Cardiac natriuretic peptides for diagnosis and risk stratification in heart failure: influences of left ventricular dysfunction and coronary artery disease on cardiac hormonal activation

BACKGROUND: Cardiac natriuretic peptides are activated in heart failure. However, their diagnostic and prognostic values have not been compared under the routine conditions of an outpatient practice. METHODS: We studied the diagnostic and prognostic value of plasma N- and C-terminal peptides of the atrial natriuretic factor prohormone (N-proANF and ANF respectively) and brain natriuretic peptide (BNP) to evaluate the severity of congestive heart failure (CHF) as reflected by the New York Heart Association (NYHA) classification and to predict its 2-year mortality. Peripheral plasma concentrations of the three natriuretic peptides were measured in 27 normal subjects (CTR), in 32 patients with coronary artery disease (CAD) and normal left ventricular ejection fraction and in 101 patients with chronic CHF in functional classes I and II (n = 61) or III and IV (n = 40). RESULTS: Plasma concentrations of the three peptides increased in the presence of CHF in relation to its severity (P < 0.01). BNP was unable to distinguish CTR from CAD, just as ANF could not differentiate CAD from CHF I-II; only N-proANF displayed a significant and continuous increase from CTR to CAD, CHF I-II and III-IV. Receiver-operating characteristic curves showed better evaluation of the degree of CHF by BNP than by ANF or ejection fraction (P < 0.05). Assessment of the 2-year prognosis revealed that N-proANF and BNP were the best independent predictors of outcome after the NYHA classification. These peptides identify a very high-mortality group. CONCLUSION: Plasma N-proANF and BNP concentrations are good indicators of the severity and prognosis of CHF in an outpatient practice. CAD does not stimulate BNP as long as ventricular dysfunction is not present, although increased N-proANF levels in this setting suggest an early humoral activation.     

Squamous cell carcinoma arising from a nonhealing wound and osteomyelitis treated with Mohs micrographic surgery: a case study

The treatment of choice for squamous cell carcinoma arising from chronic ulcer at the lower extremity has traditionally been amputation. Recently, Mohs micrographic surgery has been used as a limb-saving option in selected patients. One of these patients, a 69 year-old white male, presented with a two-year history of a progressive non-healing would and osteomyelitis. A four-month history of an enlarging mass within the ulcer suggested squamous cell carcinoma, which was confirmed by biopsies. The patient was treated with Mohs micrographic surgery for local eradication of the tumor, intravenous antibiotics, and skin grafting.