Standards of care for treating headache in primary care practice. National Headache Foundation

The following is a summary of guidelines created under the auspices of the National Headache Foundation, in an effort to improve the care of headache patients in primary care practice. The guidelines represent the consensus of an advisory panel of practitioners chosen by the NHF for their expertise in four specialty areas. A complete set of guidelines can be obtained by calling the National Headache Foundation at 1-800-843-2256 or by writing to them at 428 W. St. James Pl., 2nd Floor, Chicago, IL 60614-2750; the cost is $10.     

Progress in the development of a transcutaneously powered axial flow blood pump ventricular assist system

Development of the Jarvik 2000 intraventricular assist system for long-term support is ongoing. The system integrates the Jarvik 2000 axial flow blood pump with a microprocessor based automatic motor controller to provide response to physiologic demands. Nine devices have been evaluated in vivo (six completed, three ongoing) with durations in excess of 26 weeks. Instrumented experiments include implanted transit-time ultrasonic flow probes and dual micromanometer LV/AoP catheters. Treadmill exercise and heart pacing studies are performed to evaluate control system response to increased heart rates. Pharmacologically induced cardiac dysfunction studies are performed in awake and anesthetized calves to demonstrate control response to simulated heart failure conditions. No deleterious effects or events were encountered during any physiologic studies. No hematologic, renal, hepatic, or pulmonary complications have been encountered in any study. Plasma free hemoglobin levels of 7.0 +/- 5.1 mg/dl demonstrate no device related hemolysis throughout the duration of all studies. Pathologic analysis at explant showed no evidence of thromboembolic events. All pump surfaces were free of thrombus except for a minimal ring of fibrin, (approximately 1 mm) on the inflow bearing. Future developments for permanent implantation will include implanted physiologic control systems, implanted batteries, and transcutaneous energy and data transmission systems.     

Analysis of prognostic factors in localized gastric lymphoma: the importance of bulk of disease

PURPOSE: To identify prognostic factors in localized gastric lymphoma patients for optimal therapy selection. METHODS AND MATERIALS: From 1974 to 1990, 77 patients with localized gastric lymphoma (38 Stage IE and 39 Stage IIE) were treated with radiation therapy, chemotherapy, surgery, or a combination. Univariate and multivariate local control and survival analyses were performed on possible prognostic factors, such as patient age, gender, histologic subtype, stage, tumor size, depth of penetration, multicentricity, and treatment modality. RESULTS: At 5 years, the relapse-free survival was 52%; 74% of the relapses occurred at local sites. Smaller tumor size was most strongly associated with local control (p = .001) and relapse-free survival (p < .001). Patients with tumor sizes < or = 5 cm had relapse-free survival of 87%, compared with 41% and 15% for those with tumor sizes of 5.1 cm to 10 cm and > 10 cm, respectively. The 47 patients who received combined-modality therapy had a relapse-free survival of 65%, compared with 24% for the 30 who received single-modality therapy (p < .01). Although patient age, stage, depth of penetration, and resective surgery affected the above endpoints, these factors were not independent predictors of outcome. Analysis of treatment subgroups showed that surgical resection combined with postoperative irradiation was associated with highest local control (p = .002) and the best relapse-free survival (p = .004), when compared with other treatment modalities. In 27 patients with tumor sizes < or = 5 cm, comparison of the 15 patients who had surgery with the 12 who did not failed to reveal a local control benefit from the addition of surgery. CONCLUSION: These data demonstrate that tumor bulk is an important prognostic determinant of local control and relapse-free survival in localized gastric lymphoma patients. Stage IE and IIE lymphoma of the stomach can be selectively treated with primary radiation, but surgical resection may be necessary for large tumors (> 5 cm), followed by adjuvant radiation.     

通过燃料电池技术利用边际油田的天然气

在印度，边际矿场发现了大量天然气储量。不过它们的储量不高，有些只有5000m~3／d。这些天然气有些是属于石油伴生气。有些是独立气藏。在天然气开采及建立配套运输和应用设施前，新的边际油田的少量伴生气一般不被利用。而是烧掉。由于经济上的局限及少量的天然气用户。边际气田的天然气又不能通过传统的工艺技术得以开发利用。因此需要寻求到新的天然气利用途径。经济合理地开发这些气田。其最佳选择是采用这种高效率的燃料电池技术来发电。目前的发电装置往往不能完全满足边际地区的供电需求，因此限制了这些地区的工农业发展。     

Mutators and long-term molecular evolution of pathogenic Escherichia coli O157:H7

We report the MRI features and correlative pathologic findings of a lung cancer in a patient with progressive massive fibrosis (PMF). In this case, MRI was able to distinguish the lung cancer as a high signal intensity area, and the fibrotic mass as a low signal intensity area, on both T1-weighted and T2-weighted images when compared with muscle. MRI is potentially useful in distinguishing cancer tissue from PMF in patients with pneumoconiosis.     

Neoadjuvant chemoradiotherapy for esophageal cancer: is it worthwhile?

BACKGROUND: With promising results from several institutions, many centers began treating patients with esophageal cancer with neoadjuvant chemoradiotherapy (NC) followed by esophagectomy. This approach is demanding for the patient and has not been proved to be better than esophagectomy alone. OBJECTIVE: To assess survival time and measures of quality of life associated with NC. DESIGN: A retrospective review during 1990 to 1996. SETTING: The 3 tertiary academic hospitals affiliated with the University of Massachusetts Medical School, Worcester. PARTICIPANTS: All patients (N=51) with cancer of the middle or lower esophagus who were treated with NC followed by esophagectomy during this period. MAIN OUTCOME MEASURES: Median and 1-, 2-, and 3-year survival times; median preoperative treatment time (first office visit for surgical consultation before beginning NC to the date of surgery), median hospital stay, and postoperative swallowing function. RESULTS: The median survival time of all patients was 16.3 months; 1-, 2-, and 3-year overall survival rates were 67%, 46%, and 39%, respectively. The median hospital stay was 12 days. The median postoperative treatment time was 3.3 months, which was 20% of the median survival time. Of the 51 patients, 19 were alive with a median follow-up time of 2.5 years. Twenty-nine percent of the patients had a complete pathological response with median and 1-, 2-, and 3-year survival rates of 17.5 months, 73%, 57%, and 57%, respectively. Palliation of dysphagia was excellent, with 44 (93%) of 47 operative survivors taking either a soft diet (18 [38%]) or a regular (26 [55%]) diet by the first postoperative visit. CONCLUSIONS: Median survival time with NC followed by esophagectomy for resectable cancer of the esophagus does not appear to be significantly better than that reported for esophagectomy alone. Further, treatment time with NC consumed 20% of survival time. Examining only these outcome variables suggests that NC is not worth-while. However, examining a longer-term outcome survival variable, such as 3-year survival time, suggests that NC followed by esophagectomy may result in greater long-term survival than that reported for esophagectomy alone. We conclude that further randomized, controlled studies are necessary before NC followed by esophagectomy is considered superior to esophagectomy alone for the treatment of resectable esophageal cancer.     

Manufacture of porous biodegradable polymer conduits by an extrusion process for guided tissue regeneration

We have fabricated porous, biodegradable tubular conduits for guided tissue regeneration using a combined solvent casting and extrusion technique. The biodegradable polymers used in this study were poly(DL-lactic-co-glycolic acid) (PLGA) and poly(L-lactic acid) (PLLA). A polymer/salt composite was first prepared by a solvent casting process. After drying, the composite was extruded to form a tubular construct. The salt particles in the construct were then leached out leaving a conduit with an open-pore structure. PLGA was studied as a model polymer to analyze the effects of salt weight fraction, salt particle size, and processing temperature on porosity and pore size of the extruded conduits. The porosity and pore size were found to increase with increasing salt weight fraction. Increasing the salt particle size increased the pore diameter but did not affect the porosity. High extrusion temperatures decreased the pore diameter without altering the porosity. Greater decrease in molecular weight was observed for conduits manufactured at higher temperatures. The mechanical properties of both PLGA and PLLA conduits were tested after degradation in vitro for up to 8 weeks. The modulus and failure strength of PLLA conduits were approximately 10 times higher than those of PLGA conduits. Failure strain was similar for both conduits. After degradation for 8 weeks, the molecular weights of the PLGA and PLLA conduits decreased to 38% and 43% of the initial values, respectively. However, both conduits maintained their shape and did not collapse. The PLGA also remained amorphous throughout the time course, while the crystallinity of PLLA increased from 5.2% to 11.5%. The potential of seeding the conduits with cells for transplantation or with biodegradable polymer microparticles for drug delivery was also tested with dyed microspheres. These porous tubular structures hold great promise for the regeneration of tissues which require tubular scaffolds such as peripheral nerve, long bone, intestine, or blood vessel.     

Characterisation of 2S albumin with nutritionally balanced aminoacid composition from the seeds of Chenopodium album and its antigenic homology with seed proteins of some Chenopodiaceae and Amaranthaceae species

The low molecular weight 2S albumin protein of Chenopodium album seeds has been isolated and characterized with respect to its subunit structure by SDS-PAGE and antigenic homology with low molecular weight seed storage proteins of several other phylogenetically related species by immunoprecipitation and Western blotting. These studies revealed the existence of antigenically homologous proteins of similar molecular weights in seeds of some other members of Chenopodiaceae and Amaranthaceae. However, Chenopodium 2S albumin is antigenically unrelated to low mol.wt. albumins of dicots belonging to other families. It has a nutritionally balanced aminoacid composition in respect of essential aminoacids.     

Human immunodeficiency virus (HIV) antigen testing to detect HIV infection in female sex workers in Singapore

Human immunodeficiency virus (HIV) infection is characterised by seroconversion after a ?window? period of 2 to 3 months. After this period antibodies are usually detectable by screening tests (enzyme immunoassay or particle agglutination) confirmed by Western blot analysis. We studied 1000 newly enrolled female sex workers who had not been previously tested for HIV to assess the usefulness of HIV antigen testing to improve the efficacy of HIV infection detection. Blood was taken at enrollment for HIV antigen and HIV antibody testing. The Abbott HIVAG-1 test was used to detect antigen; antibody detection was by the Abbott recombinant HIV-1/HIV-2 3rd generation enzyme immunoassay (EIA) test, the Fujirebio Serodia-HIV particle agglutination (PA) test for screening, and the Diagnostic Biotechnology HIV Blot 2.2 Western blot (WB) test for antibody confirmation. Of the 1000 samples, 26 were positive for HIV antibody testing (26/26 for EIA, 25/25 for PA, 26/26 for WB), giving a prevalence rate of 2.6%, Of these 26 seropositive samples 1 was positive on HIV antigen testing. There were no samples which were antigen-positive and antibody-negative. HIV antigen testing does not add to increased efficacy of HIV detection among female sex workers in Singapore.