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.     

The development of Canadian nursing: professionalization and proletarianization

In this article, the development of nursing in Canada is described in terms of three major time periods: the emergence of lay nursing, including organization and registration, 1870-1930; the move to the hospital, 1930-1950; and unionization and the routinization of health care, 1950 to the present. This development is viewed in the light of the orienting concepts of professionalization, proletarianization, and medical dominance (and gender analysis). This historical trajectory of nursing shows an increasing occupational autonomy but continuing struggles over control of the labor process. Nursing is now using theory, organizational changes in health care, and credentialism to help make nursing "separate from but equal to" medicine and to gain control over the day-to-day work of the nurse. Nursing can thus be viewed as undergoing processes of both professionalization and proletarianization. As nursing seeks to control the labor process, its occupational conflicts are joined to the class struggle of white-collar workers in general. Analysis of nursing indicates the problems involved in sorting out the meaning of concepts that are relevant to occupational or class analysis but which focus on the same empirical phenomenon.     

Concurrent visual task effects on evoked and emitted auditory p300 in adolescents

Using an oddball stimulus presentation paradigm, the effects of divided attention on auditory P300s were studied. Auditory attention was either divided or focused, depending on the demands placed on subjects during the performance of a concomitantly presented visual task. Two types of auditory tasks were performed under each of the two auditory attention conditions. In one, subjects responded to infrequently presented high pitched tones (oddball stimuli). In the other they responded to the occasional omission of a stimulus in an otherwise rhythmically presented chain of stimuli. P300s and reaction times were recorded to both the rare tones and the omissions. The Sternberg visual memory task was used to manipulate the subject's auditory attention state. Subjects actively performed the Sternberg task during the divided auditory attention condition, whereas during the focused attention condition they were not required to respond to the visual stimuli. During focused auditory attention, evoked auditory P300s were both larger and faster than their emitted counterparts. During divided attention, auditory P300s were reduced in amplitude but latency was unaffected. Evoked auditory P300s showed evidence of containing P300a as well as P300b components, particularly when attention was shared with the visual task.     

Ultrastructure of malignant histiocytoma arising in the acromion.

The ultrastructural features of a malignant histiocytoma of the acromial process of the scapula were studied. Material was obtained from two surgical biopsy specimens and an amputation specimen from the tumor. Cells possessing characteristics of histiocytes, fibroblasts, xanthoma cells, and multinucleated giant cells were present throughout the tumor. Smaller numbers of undifferentiated cells and lymphocytes were also observed. Intimate cytoplasmic interdigitations between adjacent tumor cells were found, and instances of degenerating intracytoplasmic cells, possibly representing phagocytosis, were observed. Specimens stained with periodic acid-Schiff reagent with and without exposure to diastase, examined by light microscopy, showed that numerous cells contained phagocytized material consisting of degenerating cells rather than cytoplasmic glycogen. Intraumor lymphocytes apparently represented an inflammatory reaction to the tumor. The tumor giant cells and xanthoma cells were probably modified histiocytes. Results of the study were compared with previous reports of ultrastructural studies of malignant histiocytoma of soft tissues. Fundamental similarities between such studies and this one suggested that the progenitor cell is a histiocyte, whether arising in bone or in soft tissues, and that the progenitor cell is capable of differentiation in both histiocytic and fibroblastic directions.     

Interaction of somatostatin with PTH and AVP: renal effects.

Six conscious intact dogs were studied to evaluate the interactions of somatostatin (SRIF) with exogenous antidiuretic hormone arginine vasopressin (AVP). SRIF administration caused a significant increase in free water clearance compared to a vehicle-treated group: -0.91 (+/- 0.41 SD) ml/min to 0.21 (+/- 0.32 SD) ml/min in the experimental group (P less than 0.01) versus 0.21 (+/- 0.81 SD) ml/min to -0.21 (+/- 0.68 SD) ml/min in the control (P greater than 0.5). Six conscious, thyroparathyroidectomized dogs were studied to test the interaction of SRIF and parathyroid extract (PTE). There were no significant changes in the phosphaturic and hypocalciuric effects of PTE with SRIF administration. We conclude that acute systemic SRIF administration interferes with the antidiuretic action of AVP, probably at the renal-tubular level, but does not antagonize the renal actions of PTE.