Intensity-dependent regional cerebral blood flow during 1-Hz repetitive transcranial magnetic stimulation (rTMS) in healthy volunteers studied with H215O positron emission tomography: I. Effects of primary motor cortex rTMS.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) affects the excitability of the motor cortex and is thought to influence activity in other brain areas as well. We combined the administration of varying intensities of 1-Hz rTMS of the motor cortex with simultaneous positron emission tomography (PET) to delineate local and distant effects on brain activity. METHODS: Ten healthy subjects received 1-Hz rTMS to the optimal position over motor cortex (M1) for producing a twitch in the right hand at 80, 90, 100, 110, and 120% of the twitch threshold, while regional cerebral blood flow (rCBF) was measured using H(2)(15)O and PET. Repetitive transcranial magnetic stimulation (rTMS) was delivered in 75-pulse trains at each intensity every 10 min through a figure-eight coil. The regional relationship of stimulation intensity to normalized rCBF was assessed statistically. RESULTS: Intensity-dependent rCBF increases were produced under the M1 stimulation site in ipsilateral primary auditory cortex, contralateral cerebellum, and bilateral putamen, insula, and red nucleus. Intensity-dependent reductions in rCBF occurred in contralateral frontal and parietal cortices and bilateral anterior cingulate gyrus and occipital cortex. CONCLUSIONS: This study demonstrates that 1-Hz rTMS delivered to the primary motor cortex (M1) produces intensity-dependent increases in brain activity locally and has associated effects in distant sites with known connections to M1.     

Influence of hypothermic cardiopulmonary bypass on atrial natriuretic factor levels

Atrial natriuretic factor (ANF) is a peptide released from the heart in response to atrial distension. This peptide causes diuresis, vasodilatation, decreased blood pressure, and antagonizes the renin-aldosterone and antidiuretic hormone neuraxes. The influence of cardiopulmonary bypass and cardiac surgery on the circulation and release of ANF is unknown. Plasma ANF concentrations were therefore determined in patients undergoing coronary artery revascularization (CABG) and mitral valve replacement (MVR). Peptide levels were unchanged following anaesthetic induction. Plasma ANF concentrations decreased significantly during hypothermic (less than or equal to 28 degrees C) cardiopulmonary bypass in both patient groups. After 60 minutes of cardiac bypass, ANF declined from (mean +/- SEM) 512 +/- 132 to 20 +/- 6 pg.ml-1 (P less than 0.05) during MVR, and from 178 +/- 41 to 110 +/- 48 pg.ml-1 during CABG (P less than 0.05). Rewarming during bypass was associated with an increase in ANF concentration in both groups. Heparin anticoagulation and protamine reversal had no effect on immunoreactive ANF levels. In patients undergoing CABG, there was a linear relationship between plasma ANF concentration (pg.ml-1) and right atrial pressure (mmHg) prior to cardiopulmonary bypass (r = 0.86, P less than 0.005). However, one and three hours after cardiopulmonary bypass there was no significant relationship between right atrial pressure and ANF plasma levels. These results suggest that reduction in plasma ANF concentration occurs during hypothermic cardiopulmonary bypass. Furthermore, the proportional relationship between atrial distension and circulating ANF concentration was altered following cardiac surgery.     

Evaluation of a Hong Kong Chinese version of a self-administered questionnaire for assessing symptom severity and functional status of carpal tunnel syndrome: cross-cultural adaptation and reliability.

OBJECTIVES: To evaluate the application of a translated version of an established self-administered questionnaire for carpal tunnel syndrome on Chinese patients in Hong Kong. DESIGN: Evaluation of an instrument tool. SETTING: Department of Orthopaedics and Traumatology, Queen Mary Hospital, Hong Kong; Holistic Medical Centre, Aberdeen, Hong Kong. PARTICIPANTS: Patients with carpal tunnel syndrome, translators. MAIN OUTCOME MEASURES: The adaptation was based on forward-backward translation from English to Chinese (Hong Kong) and vice versa. Meetings with translators, investigators, and patients were organised to generate an acceptable version of the questionnaire. A pilot study was carried out on 20 patients and subsequently minor adjustments were added. Fifty patients were recruited to validate the reliability and internal consistency of the questionnaire. RESULTS: The ordinality of response agreed with the original instrument. Test-retest reproducibility showed no significant difference between tests. The Pearson correlation coefficient ranged from 0.83 to 0.93. Internal consistency was good, at 0.85. CONCLUSION: Through the validation of the Hong Kong Chinese version of the questionnaire, we are able to produce an assessment tool for the local patients. Furthermore, we are able to create a platform for: (i) a cross-national and cross-cultural epidemiological comparison as well as a means of (ii) evaluating different types of treatments.     

Characterization of the Cryptosporidium antigens from sporulated oocysts of Cryptosporidium parvum.

The antigenic constituents of sporulated Cryptosporidium parvum oocyst antigens were characterized with antisera from mice immunized against C. parvum. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by silver staining defined the major proteins. Six of seven lectins used recognized as many as 15 bands. The lectins concanavalin A, Dolichos biflorus, and wheat germ agglutinin showed strong activity against the same eight bands with molecular weights ranging from 72,000 to greater than 100,000. An enzyme-linked immunosorbent assay was used to detect antibody to C. parvum. Antibody binding was significantly decreased by heat and enzymatic treatment with trypsin, protease, and mixed glycosidases. C. parvum antigens were further defined by the reactivity of immune sera with a C. parvum sonicate preparation separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electrophoretically transferred to nitrocellulose paper. Antisera from orally infected mice consistently recognized four antigens with molecular weights ranging from 72,000 to greater than 100,000. These antigens also bound concanavalin A. Treatment of the antigen preparation with mixed glycosidases reduced the reactivity of antisera with most antigens with molecular weights greater than 60,000. The data suggest that the antigenic composition of C. parvum is complex and that carbohydrates alone or in association with lipids or proteins may be important in the immune response to C. parvum.     

Adolescent Immunization: Focus on Implementation

ABSTRACT: On March 11–12, 1996, a workshop on how to implement new adolescent immunization (AI) recommendations was held in Atlanta, Ga. Sponsored by the Centers for Disease Control and Prevention, it was a collaborative effort of the National Immunization Program, the Division of Adolescent and School Health/National Center for Chronic Disease Prevention and Health Promotion, and the Hepatitis Branch/National Center for Infectious Diseases. The workshop brought together organizations and individuals interested in adolescent health and immunizations so they could address how new Al recommendations can be implemented most effectively. This article offers an overview of their discussions and suggestions, including issues of cooperation, education, legislation, and Al program development among health provider organizations, health departments, schools, community groups and various other agencies relating to adolescent health services.     

Laparoscopic nephrectomy is cost effective compared with open nephrectomy in a large county hospital.

BACKGROUND AND OBJECTIVES: To evaluate the experience with laparoscopic nephrectomy in a large county hospital and perform a cost comparison between uncomplicated open and laparoscopic nephrectomy. METHODS: Eleven consecutive patients who underwent an uncomplicated laparoscopic nephrectomy in a large county hospital were compared with 8 patients who underwent uncomplicated open nephrectomy during the same period. Patient charts and corresponding billing records were reviewed to determine overall hospitalization cost and individual cost components. RESULTS: No perioperative complications occurred in either the laparoscopic or open group, and no statistically significant differences existed between groups with regard to patient demographics or operative parameters. The overall operating room costs favored the open nephrectomy group by dollars 1070 (P=0.003). However, the overall cost of hospitalization, surgeon professional fees, duration of hospitalization, room and board costs, laboratory, and radiology costs, pharmacy costs, intravenous solution and infusion pump costs all significantly favored the laparoscopic patient group. The mean difference in overall hospital cost between laparoscopic and open nephrectomy was dollars 1211 in favor of laparoscopy (P=0.037). CONCLUSIONS: Our experience with laparoscopic nephrectomy in a large county hospital demonstrates a clear economic advantage in favor of the laparoscopic approach. Given limited funding for public hospitals and a clear patient benefit, laparoscopic nephrectomy should constitute first-line therapy when nephrectomy is indicated.     

Renal transplant function after ten years of cyclosporine.

Although the nephrotoxic side effects of cyclosporine are well known, the impact of long-term CsA on renal transplant function is uncertain. We studied 5-10-year renal function in 347 CsA-treated patients, and in 64 randomly selected non-CsA-treated patients who had a minimum of 55 months of graft function. Non-CsA patients had a lower creatinine (Cr) level at one year than CsA patients (P = .001), with no change in renal function over time (P = .6). In CsA-treated patients there was also no suggestion of progressive renal damage, as evidenced by no change in Cr or 1/Cr. Simple linear regression models of 1/Cr vs. time for the first 10 years posttransplant were fit to the data for each patient. Analysis of the Y-intercept estimates from these regressions showed that age (P = .001), sex (P = .001), cyclosporine toxicity (P = .024), and initial cyclosporine dosage (P = .016) significantly affected the one-year serum Cr. Variables not affecting one-year Cr included donor source, early rejection episodes, late rejection episodes, ATN, diabetes, transplant number, HLA ABDR mismatch (for cadaver transplants), maximum PRA, and PRA at transplant. Analysis of the slope estimates from the regressions revealed that only age (P = .001) and late rejection episodes (P = .001) significantly affected the rate of change in 1/Cr over time. We conclude that, in long-term renal transplant patients, there is no evidence of progressive deterioration in renal function due to CsA nephrotoxicity.     

Modified nephro-ureterectomy. Long-term follow-up with particular reference to subsequent bladder tumours

Nephro-ureterectomy is the standard treatment for transitional carcinoma of the renal pelvis and caliceal system. In recent years a modification of the conventional two-incision technique has been described in which the intramural ureter is resected endoscopically and the remaining ureter is removed in continuity with the kidney through a single loin incision. Twenty-one patients had their renal pelvic tumours treated by this modified technique between 1970 and 1983. Of 16 patients available for analysis, 37.5% subsequently developed bladder tumours. It was concluded that this modified technique has no greater incidence of subsequent bladder tumour development than the conventional technique of nephro-ureterectomy, whilst giving considerable benefit to the patient.     

The effectiveness of fibrin glue sealant for reducing experimental pulmonary ari leak

The effectiveness of fibrin glue as a biological sealant for pulmonary air leaks was determined in 16 dogs. A standardized pleural defect was made in the left lower lobe, and the quantity of air passing through a chest tube was assessed with a Collins respirometer. For the 8 randomly assigned control animals, the air leak decreased over 90 minutes from a mean of 1.4 L/min to a mean of 1.1 L/min (mean decrease, 19.8%). In the 8 randomly assigned fibrin glue-treated animals, the air leak decreased from a mean of 2.1 L/min to a mean of 0.5 L/min (mean decrease, 80.8%) (p less than 0.0001). Postoperative evaluation of survivors disclosed no increased adhesions in the glue-treated animals and complete resorption of the glue at 3 months. We conclude that in this animal model, fibrin glue reduced the size of pulmonary air leaks in the early period after thoracotomy and did not lead to increased intrapleural adhesions.     

Completion pneumonectomy: indications, complications, and results

From 1958 through 1985, a total of 113 consecutive patients had completion pneumonectomy (CP). Indications for pulmonary resection resulting in CP were lung cancer (LC) in 64 patients, pulmonary metastases (PM) in 20, and benign lung disease (BLD) in 29. Operative mortality was 12.4% (14 deaths) but varied according to the indication for CP. Mortality was 9.4% for LC, 0% for PM, and 27.6% for BLD. Forty-three patients (38.1%) had major complications (26 of 64 with LC, 40.6%; 1 of 20 with PM, 5.0%; and 16 of 29 with BLD, 55.2%). Five-year actuarial survival for patients with LC was 26.4% but varied according to stage. Five-year survival for patients with PM was 40.8% and with BLD was 27.2%. We conclude that CP for BLD carries marked operative mortality and morbidity, usually due to intense reaction around hilar structures and concurrent active infection or fistula. In contrast, CP for LC and PM can be performed with low mortality, acceptable morbidity, and gratifying long-term survival.