Pulmonary function following surgical repair of pectus excavatum: a meta-analysis.

The purpose of this study was to use a meta-analytical technique to examine the efficacy of surgical repair of pectus excavatum on pulmonary function. Studies were retrieved via computerized literature searches, cross-referencing from original and review articles. Inclusion criteria were as follows: (1) reporting quantitative measures of preoperative and postoperative pulmonary function; (2) published in the English language; (3) indexed between January 1960 and September 2005; (4) reporting the duration between which preoperative and postoperative assessments were conducted; and (5) describing the pulmonary assessment procedures. The titles and abstracts of potentially relevant articles were reviewed to determine whether they met the criteria for inclusion. Twelve studies representing 313 pectus excavatum patients met the inclusion criteria and were used for the meta-analysis. Random-effects modeling yielded a mean weighted effect size (ES) for pulmonary function which was statistically nonsignificant (ES=0.08, 95% CI=-0.20 to 0.35; P=0.58). The findings of the present study indicated that surgical repair of pectus excavatum does not significantly improve pulmonary function. These findings, however, may be a result of testing pulmonary function under conditions in which pectus excavatum does not manifest itself.     

Hemagglutination and proteoglycan binding by the Lyme disease spirochete, Borrelia burgdorferi.

The ability of the Lyme disease spirochete to attach to host components may contribute to its ability to infect diverse tissues. We present evidence that the Lyme disease spirochete expresses a lectin activity that promotes agglutination of erythrocytes and bacterial attachment to glycosaminoglycans. Among a diverse collection of 21 strains of Lyme disease spirochete, hemagglutinating activity was easily detected in all but 3 strains, and these three strains were noninfectious. The ability to agglutinate erythrocytes was associated with the ability of the spirochete to bind to the sulfated polysaccharide dextran sulfate and to mammalian cells. Soluble dextran sulfate was a potent inhibitor of both hemagglutination and attachment to mammalian cells, while dextran had no effect on either activity, suggesting that dextran sulfate may inhibit attachment by mimicking host cell glycosaminoglycans. Consistent with this, the spirochete bound to immobilized heparin, and soluble heparin inhibited bacterial adhesion to mammalian cells. The bacterium did not bind efficiently to Vero cells treated with heparinase or heparitinase or to mutant CHO cell lines that are deficient in proteoglycan synthesis. Sulfation of glycosaminoglycans was critical for efficient bacterial recognition, as Vero cells treated with an inhibitor of sulfation, or a mutant CHO cell line that produces undersulfated heparan sulfate, did not mediate maximal spirochetal binding. Binding of the spirochete to extracellular matrix also appeared to be dependent upon this attachment pathway. These findings suggest that a glycosaminoglycan-binding activity which can be detected by hemagglutination contributes to the attachment of the Lyme disease spirochete to host cells and matrix.     

Recurrent thyroid cancer. Role of surgery versus radioactive iodine (I131)

OBJECTIVE: This retrospective study compared treatment and survival of patients with recurrent well-differentiated thyroid cancer that was diagnosed exclusively by I131 scanning, or by clinical examination. SUMMARY BACKGROUND DATA: Despite the usual excellent prognosis of differentiated thyroid cancer, approximately half of patients who developed a recurrence eventually succumb to the disease. It has been speculated, but not proven, that recurrent disease detected solely by I131 scanning may offer a better prognosis than recurrences detected clinically and be amendable to I131 ablative therapy without the addition of surgical resection. METHODS: Seventy-four cases of recurrent differentiated thyroid cancer were identified retrospectively and examined regarding the location of recurrence, mode of detection of recurrent disease, treatment of recurrence, and outcome of patients. Using Fischer exact testing, outcome results for recurrences detected exclusively by I131 scan was compared to that of clinically diagnosed recurrences; among clinically detected recurrent cases, treatment with surgery only was compared to surgery/I131 ablation. Kaplan-Meier actuarial survival curves were generated for clinically detected recurrent cancer treated by surgery only and compared to those treated by surgery and I131 ablation using Gehan-Wilcoxon and log-rank analysis. RESULTS: Recurrences located most commonly were regional (53%), followed by local (28%), distant metastasis (13%), and combined locoregional (6%). Among patients whose recurrence was detected scintigraphically, only 9.5% had persistence of disease or were dead of disease compared to 54.0% of patients with clinically detected recurrences. Radioactive iodine ablation in scintigraphically detected recurrences salvaged 18 of 20 patients (90%). Among clinically detected recurrences, surgery alone salvaged 12 of 21 patients (57%), whereas the addition of I131 ablation to surgery salvaged only 3 of 15 patients (20% p = 0.05). CONCLUSION: The probability of dying or living with persistent disease after treatment of recurrent thyroid cancer is less for I131 detected recurrences compared to clinically diagnosed recurrences; I131 ablation without surgery constitutes adequate therapy for scintigraphically detected recurrences. In clinically recurrent disease, the addition of I131 ablation to curative resection does not appear to improve survival.     

Short-Ti inversion-recovery pulse sequence: analysis and initial experience in cancer imaging

Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy.     

Solitary rectal ulcer syndrome: findings at barium enema study and defecography

Sixteen cases of histopathologically proved solitary rectal ulcer syndrome were encountered. Fifteen patients underwent barium enema study; in nine cases the findings--including rectal stricture, granularity of the mucosa, and thickened rectal folds-were nonspecific. In six cases the study was normal. All patients had a long history of defecation disorders, and defecography was performed in all. In seven cases, intussusception of the rectal wall was seen; in another case the intussusception was accompanied by a rectocele. One case showed rectal prolapse. In four cases, failed relaxation of the puborectalis occurred and prevented the passage of the bolus; in another case there was abnormal perineal descent. In two patients studies were normal. In patients with defecation disorders, the possibility of this syndrome should be considered. Defecography is the method of choice for establishing the diagnosis.