Ten steps for proper peripheral nerve handling during inguinal hernia surgery.

INTRODUCTION: Post-inguinal pain after a hernia surgery is prevalent and can be quite frustrating for the surgeon and patient alike. There are several sources for possible post-operative inguinal pain after a successful hernia repair; however, in the setting where a recurrent inguinal hernia is not present, it is likely related to the nerves in the inguinal canal or pelvis. Chronic inguinal groin pain after hernia repairs have been reported in a high percentage of patients following inguinal hernia surgery despite being one of the most common procedures performed annually in the USA and worldwide. MATERIALS AND METHODS: We present ten of the basic concepts utilized by peripheral nerve surgeons to limit nerve injury, which can easily be applied to open inguinal hernia surgery with or without mesh, starting with the firm understanding of the inguinal anatomy to addressing the nerves, meticulous placement of the mesh and the active revision of the surrounding structures and nerve position before closure. CONCLUSIONS: Understanding the proper handling of the inguinal nerves during hernia surgery can decrease the incidence of post-operative chronic pain by employing microsurgical concepts to day-to-day surgical procedures and prevent complications in an extensive set of patients.

Nurse migration and its implications for Philippine hospitals.

BACKGROUND: 'Push' and 'pull' factors motivate Filipino registered nurses (RNs) to leave for employment in foreign countries making the Philippines the leading source country for nurses overseas. OBJECTIVE: To assess the current RN-staffing situation in Philippine hospitals. DESIGN: A self-administered survey was mailed to a sample of 200 Philippine hospital chiefs of nurses. RESULTS: According to respondents, the majority of RNs in their hospitals (73%) were aged 40 years and younger and female (85%); government hospital RNs earned higher wages than private hospital RNs; and on average, RN vacancy rates and RN turnover rates were lower in government hospitals than private hospitals. All respondents reported no difficulty recruiting RNs with less than 12 months of work experience. However, recruitment of more experienced RNs was somewhat or very difficult for private hospitals compared with government hospitals. Higher salaries, better benefits and good career opportunities were identified as most effective incentives for both recruitment and retention. CONCLUSIONS: RN staffing in government hospitals is more favourable than in private hospitals as measured by employment tenure, vacancy rates, turnover rates and ability to recruit and retain more experienced RNs. On average, respondents reported over half (59%) of total RN turnover was the result of nurse migration overseas.

The migration of physicians from sub-Saharan Africa to the United States of America: measures of the African brain drain

Background: The objective of this paper is to describe the numbers; characteristics; and trends in the migration to the United States of physicians trained in sub-Saharan Africa. Methods: We used the American Medical Association 2002 Masterfile to identify and describe physicians who received their medical training in sub-Saharan Africa and are currently practicing in the USA. Results :More than 23of America's 771 491 physicians received their medical training outside the USA; the majority (64) in low-income or lower middle-income countries. A total of 5334 physicians from sub-Saharan Africa are in that group; a number that represents more than 6of the physicians practicing in sub-Saharan Africa now. Nearly 86of these Africans practicing in the USA originate from only three countries: Nigeria; South Africa and Ghana. Furthermore; 79were trained at only 10 medical schools. Conclusions: Physician migration from poor countries to rich ones contributes to worldwide health workforce imbalances that may be detrimental to the health systems of source countries. The migration of over 5000 doctors from sub-Saharan Africa to the USA has had a significantly negative effect on the doctor-to-population ratio of Africa. The finding that the bulk of migration occurs from only a few countries and medical schools suggests policy interventions in only a few locations could be effective in stemming the brain drain

Pediatric environmental health: perceptions from a survey questionnaire.

To expand the base of knowledge regarding perceptions about potential environmental threats to children's health, a survey was conducted in the Northwest United States. Samples of Head Start parents, PTA presidents, public health officials, school nurses, naturopathic physicians, family practitioners, and pediatricians were mailed a questionnaire inquiring into the nature and degree of concerns about pediatric environmental health. The response rate was 24%. Trends in the data showed disparities in perceptions regarding levels of concern and exposure concerns between respondent categories. Disparities also existed regarding information resources used for children's environmental health. Recognizing differences in perceptions of children's environmental health, as demonstrated in these results, may be useful for risk communication and resource allocation, especially in the context of the wide variety of health belief models. Such knowledge may help clarity situations with environmental health risk concerns, including clinical, public health, and educational circumstances.

Integrating Healthy Communities concepts into health professions training.

To meet the demands of the evolving health care system, health professionals need skills that will allow them to anticipate and respond to the broader social determinants of health. To ensure that these skills are learned during their professional education and training, health professions institutions must look beyond the medical model of caring for communities. Models in Seattle and Roanoke demonstrate the curricular changes necessary to ensure that students in the health professions are adequately prepared to contribute to building Healthy Communities in the 21st century. In addition to these models, a number of resources are available to help promote the needed institutional changes.

The use of community surveys for health planning: the experience of 56 northwest rural communities.

A rural health services development program of the University of Washington School of Medicine has worked for 15 years with communities throughout the five-state region of Alaska, Idaho, Montana, Washington and Wyoming to strengthen their health systems. In the course of that work, 56 communities were surveyed about their utilization and opinions of local health systems. This database allows the following generalizations to be made about rural Northwest communities: (1) People think highly of their local hospitals, physicians and other key components of the acute medical care system and want their hospitals to remain open. Older respondents are more satisfied than younger respondents; (2) the typical hospital market share is 36 percent, the typical physician market share is 50 percent (3) satisfaction with discrete, well-funded services such as pharmacy, ambulance and dentistry is quite high, whereas satisfaction with mental health and substance abuse treatment is significantly lower; (4) the most commonly cited serious problems in surveyed communities were "too few physicians or- services" and "care is too expensive"; and (5) there is great variation between communities in both satisfaction and utilization.

Barriers and solutions in implementing occupational health and safety services at a large nuclear weapons facility.

The Hanford Nuclear Reservation is one of the U.S. Department of Energy's largest nuclear weapons sites. The enormous changes experienced by Hanford over the last several years, as its mission has shifted from weapons production to cleanup, has profoundly affected its occupational health and safety services. Innovative programs and new initiatives hold promise for a safer workplace for the thousands of workers at Hanford and other DOE sites. However, occupational health and safety professionals continue to face multiple organizational, economic, and cultural challenges. A major problem identified during this review was the lack of coordination of onsite services. Because each health and safety program operates independently (albeit with the guidance of the Richland field operations office), many services are duplicative and the health and safety system is fragmented. The fragmentation is compounded by the lack of centralized data repositories for demographic and exposure data. Innovative measures such as a questionnaire-driven Employee Job Task Analysis linked to medical examinations has allowed the site to move from the inefficient and potentially dangerous administrative medical monitoring assignment to defensible risk-based assignments and could serve as a framework for improving centralized data management and service delivery.

Improving a rural hospital's peer review process.

Quality monitoring in a small rural hospital is a challenge on many fronts. The case study presented here illustrates a quality monitoring failure and analyzes the contributing factors. Based on their experience, the authors suggest methods to improve small rural hospital quality monitoring.

Characterization and evaluation of a recombinant hepatitis B vaccine expressed in yeast defective for N-linked hyperglycosylation.

The hepatitis B (HB) virus preS2 + 2 polypeptide (the M or middle envelope polypeptide) is N-glycosylated at the N4 residue of the preS2 domain when expressed in recombinant yeast. Hyperglycosylation at this amino acid residue (the addition of a large number of mannose residues to the core oligosaccharide), which occurs in common yeast strains, results in an HB vaccine with diminished immunogenicity. Hyperglycosylation can be prevented by expressing the preS2 + S polypeptide in mutant yeast strains (e.g. mnn9) which limit N-linked glycosylation to the addition of only core saccharide residues. An HB vaccine prepared from recombinant yeast expressing the non-hyperglycosylated preS2 + 2 polypeptide was of similar immunogenicity in mice to a licensed HB vaccine and was much more immunogenic in humans than the hyperglycosylated preS2 + 2 vaccine.

Immunogenicity of conjugate vaccines consisting of pneumococcal capsular polysaccharide types 6B, 14, 19F, and 23F and a meningococcal outer membrane protein complex.

In an effort to prepare pneumococcal (Pn) capsular polysaccharide (Ps) vaccines that would be immunogenic in infants, covalent conjugates were prepared for Pn types 6B, 14, 19F, and 23F. Each Ps type was covalently bound to an outer membrane protein complex from Neisseria meningitidis serogroup B and evaluated for immunogenicity in mice and infant monkeys. The conjugates induced specific anti-Ps antibody responses in mice and in infant rhesus and African green monkeys; a conjugate of 6B and outer membrane protein complex was immunogenic at Ps doses as low as 20 ng. Although low levels of the Pn group-common cell wall polysaccharide were present in all type-specific Ps preparations, anti-cell wall polysaccharide responses induced by covalent conjugates were < 1% of the total anti-Ps response after two doses of vaccine. In contrast, the anti-cell wall polysaccharide response of a noncovalent conjugate represented 41% of the anti-Ps response after two doses. Relative T-cell dependence, a requirement for the human target population of infants less than 18 months old, was demonstrated for all four Pn Ps conjugates in an athymic mouse model. Therefore, these Pn Ps-outer membrane protein complex conjugate vaccines are excellent candidates for evaluation in human infants.

Characterization of recombinant antistasin secreted by Saccharomyces cerevisiae.

Secretion from recombinant yeast was used as a potential source of large quantities of the leech protein antistasin (ATS), a potent and highly specific inhibitor of the serine protease coagulation factor Xa. Mature recombinant ATS (r-ATS) is obtained after intracellular cleavage by the yscF protease of the mating factor alpha-1 pre-proleader from the fusion protein at the Lys-Arg sequence junction. Production levels are relatively low (ca. 1 mg/liter). Purification of the secreted product from a complex growth medium involved cell removal by microfiltration and diafiltration, cation-exchange capture and concentration on S-Sepharose Fast Flow, C-4 reverse-phase high-performance liquid chromatography (RP-HPLC), and HPLC cation-exchange chromatography step, and RP-HPLC concentration and desalting. The process was scaled up from the 16- to the 250-liter level with a corresponding increase in amount of r-ATS. From the 250-liter fermentation two major forms, r-ATS-I and r-ATS-II, distributed approximately 60:40, and a minor form, r-ATS-minor (ca. 1% of the purified r-ATS), were characterized. Limited N-terminal sequence analysis by Edman degradation indicated that r-ATS-I has the predicted mature N-terminus starting with Gln, that r-ATS-II is N-terminally blocked with pyroglutamate, and that r-ATS-minor is an incompletely processed form. RP-HPLC, hydrophilic-interaction HPLC, cation-exchange HPLC analysis, and electrophoresis results are consistent with the differences observed by sequencing. Preliminary in vitro characterization by intrinsic Ki determination for factor Xa inhibition indicated that the yeast r-ATS forms are indistinguishable from each other as well as from r-ATS expressed by the insect baculovirus host-vector system. Nevertheless, r-ATS-I and r-ATS-II appear less potent than insect-derived r-ATS in the activated partial thromboplastin time clotting assay. Further characterization indicated that C-terminal cleavage at Pro-116 had occurred in r-ATS-I and r-ATS-II as well as oxidation of methionine residues to methionine sulfoxide. The possible role of the C-terminus in inhibition of the prothrombinase complex is discussed.

The application of molecular biology to the development of novel vaccines.

In summary, we have shown that yeast is the preferred host for the expression of recombinant-derived hepatitis B vaccines, and that a yeast expression system which is productive, stable and scaleable can be developed for each of the three HBV envelope proteins. The versatility of regulated and integrated yeast expression systems in the production of foreign polypeptides with biomedical utility also has been highlighted. We also have shown that careful attention to the development of recombinant clones helps to optimize the entire production process leading to highly purified products which share many biochemical properties with the plasma-derived vaccine. Furthermore, immunization with PreS2 sequences is capable of protecting chimpanzees from HBV infection. The availability of PreS2 + S and PreS1 + PreS2 + S proteins expressed in yeast now provides the opportunity for establishing the relevance of such candidate vaccines in preventing human disease, thereby highlighting the utility of molecular biology in modern vaccine development.

A candidate vaccine for hepatitis B containing the complete viral surface protein.

The entire surface protein of hepatitis B virus serotype ayw containing the preS (preS1+preS2) and S domains has been expressed in the yeast Saccharomyces cerevisiae. Yeast containing a recombinant plasmid utilizing a constitutive promoter did not express this gene successfully due to the toxicity of the protein. A plasmid using a regulatable promoter directed expression which initiated late in the exponential phase of growth and resulted in the accumulation of high intracellular levels of the complete surface protein. The purified polypeptide aggregates into a form which, although not comprised of typical 20 nm particles, displays antigenic determinants encoded by the preS1, preS2 and S domains. Immunization of rabbits elicited the formation of antibodies directed against all three domains. This candidate vaccine will be useful for studying the contributions to viral immunity of the host response to the preS1 and preS2 domains.

Ethical dilemmas in providing health care to workers.

The internist, expected to play an increasing role in occupational medicine, is likely to encounter ethical dilemmas in treating working patients, including those involving loyalty, confidentiality, reporting known or suspected occupational hazards and diseases, and maintaining awareness about occupational health factors. Many of these dilemmas become realized when the internist integrates occupational health services into general internal medicine practice, particularly when these services are important to employment decisions, such as the preemployment and periodic examinations. Appropriate responses to these dilemmas and the situations from which they arise can be formulated, based on accepted ethical and legal principles.

Unusually high-level expression of a foreign gene (hepatitis B virus core antigen) in Saccharomyces cerevisiae.

As a model system for the study of factors affecting gene expression, hepatitis B virus core antigen (HBcAg) has been expressed in the yeast Saccharomyces cerevisiae. The singularly high levels of expression achieved are approx. 40% of the soluble yeast protein. The HBcAg polypeptides are present as 28-nm particles which are morphologically indistinguishable from HBcAg particles in human plasma and are highly immunogenic in mice. The plasmid construction employed to achieve these very high levels of expression utilizes the constitutively active yeast promoter from the GAP491 gene which is fused in a way that all non-translated sequences flanking the HBcAg coding region are yeast-derived. Hybrid constructions containing 3'-nontranslated viral DNA (yeast 5') or 5'-nontranslated viral DNA (yeast 3') as well as a construction with both 5'- and 3'-nontranslated viral DNA also have been made. A comparison of these constructions for levels of HBcAg expression indicates that the strongest contributor to the high levels of protein is the presence of 5'-flanking sequences which are yeast-derived; secondarily, a significant improvement can be achieved if the 3'-flanking sequences also are yeast-derived. The high abundance of HBcAg in the highest producer is explicable in part on the basis of the very high stability in yeast cells of HBcAg polypeptides. Analysis of the HBcAg coding sequence reveals a very low index of codon bias for S. cerevisiae, largely discounting codon usage as a contributor to the high level of protein obtained.

Experimental allergic aspermatogenic orchitis. IV. Chemical properties of sperm glycoproteins isolated from guinea pig testes.

Of four glycoproteins isolated from guinea pig testes, two were aspermatogenic (types I and IV) and two (types II and III) were inactive. The glycoproteins were rich in carbohydrate, varying from 41.5% to 49.5% carbohydrate by weight. Each glycoprotein had a unique amino acid composition, but in general low levels of tyrosine, tryptophan, and basic amino acids were found along with relatively high contents of serine, threonine, glutamic acid, and proline. Types I and IV glycoproteins were remarkably stable; their aspermatogenic activity was not affected by urea, trypsin, or heating at 100 degrees C in water or in 1 M HCl for 15 min. Carbohydrate analysis revealed little difference in the monosaccharide compositions of types I and IV glycoproteins, except that only the type I contained sialic acid. In contrast, types II and III glycoproteins lacked sialicacid and fucose and contained much less mannose. Both N-acetylglucosamine and N-acetylgalactosamine were present in all four glycoproteins, and they dominated in the types II and III. Fucose and at least 20-25% of the galactose appeared to occupy terminal positions in type IV glycoprotein as shown by their release after 15 min hydrolysis in 1 M HCl. All of the glycoproteins contained a relatively high percentage of galactose by weight, from 12.6 to 19.3%. The molecular weights of the glycoproteins were estimated by sodium dodecyl sulfate gel electrophoresis to be 47000, 105000 and 18000 respectively for the types I, II, and IV; type III glycoprotein showed two major bands, with molecular weights of 41500 and 22800. All the above molecular weight values are probably overestimated because of high carbohydrate content. The molecular weight of type IV glycoprotein was found to be 13000 by ultracentrifugation; a corrected value of 29000 was calculated for type I glycoprotein.

Experimental allergic orchitis and aspermatogenesis. VI. Transfer of allergic orchitis with immune cells.

Typical experimental allergic orchitis (EAO) and aspermatogenesis were successfully transferred to strain 13 guinea pigs with peritoneal exudate and lymph node cells from male and female donor guinea pigs (lacking detectable antibody) previously sensitized with 9 mug of highly purified GP1 glucoprotein isolated from the sperm acrosome. Attempts to transfer the disease with circulating antibody from hyperimmunized animals were not successful. These studies support a cell-mediated basis for the immunopathologic events in EAO.

Experimental allergic aspermatogenic orchitis. II. Some chemical properties of the AP1 protein of the sperm acrosome.

The AP1 protein, a unique aspermatogenic protein localized in the sperm acrosome, exists as a single polypeptide chain of 136 amino acids, as shown by a single band on gel electrophoresis in sodium dodecyl sulfate and the recovery of the expected 21 to 22 tryptic peptides on peptide mapping. The AP1 protein appears to exist in a compact, highly stable conformation, as shown by its resistance to trypsin hydrolysis. Its aspermatogenic acitivity is not affected by trypsin treatment, by heating at 99 degrees C for 1 h, by 8 M urea, or by acid conditions. After reduction and alkylation, however, the molecule appears to open up, since it becomes hydrolyzable by trypsin and migrates more slowly on gel electrophoresis at pH 2.7 and 8.6. After alkylation, the AP1 protein still migrates as a single band at pH 2.7. The AP1 protein shows microheterogeneity near its isolectric point at pH 8.6; each of five bands shows the same amino acid analysis. Aggregation was not observed following treatment with dimethylsuberimidate. The molecular weight of 15 000, obtained from gel electrophoresis consists of 136 amino acids with a relatively high content of proline, half cystine, glycine, histidine and tryptophan. No galactose, mannose, fucose, glucose, or hexosamines were found; the AP1 protein is thus not a glycoprotein.

Experimental allergic aspermatogenic orchitis. III. Isolation of spermatozoal glycoproteins and their role in allergic aspermatogenic orchitis.

Four glycoproteins (GP1,2,3 and 4) rich in carbohydrate were isolated from guinea pig testes. GP1, 2, and 4 (one or more) were localized in the sperm acrosome by the indirect immunofluorescence technique. Purification consisted of delipidation with chloroform-methanol (2:1), acid extraction at pH 3.0, precipitation with 85% saturated ammonium sulfate, extraction with 5% trichloroacetic acid, and either gel filtration on agarose or ultrafiltration. The final purification steps were isoelectrofocusing or gel filtration on Sephadex G-75 followed by preparative slab gel electrophoresis at pH 8.6. Each glycoprotein appeared homogeneous by gel electrophoresis at pH 2.7 and 8.6, and by immunoelectrophoresis. The crude glycoprotein fraction from the agarose column was resolved into the three major components, GP1, 2, and 3, distinguished by their isoelectric points (pI 3.9, 4.4, and 5.0, respectively), electrophoretic mobilities at pH 8.6, and reactivities with antiserum in immunoelectrophoresis. GP4, isolated by ultrafiltration and Sephadex G-75 chromatography, was differentiated by the same criteria. Approximately 5 mg each of purified GP1, 3, and 4 and 2 to 3 mg of GP2 were isolated from 1000 g of wet guinea pig testes. GP1, 2, and 4 induced precipitating antibody in rabbits and goats. GP1 and GP4 induced allergic aspermatogenic orchitis in guinea pigs, an autoimmune disease characterized by infiltration of mononuclear cells around and within the seminiferous tubules, followed by extensive destruction of the germinal epithelium. The course of the disease induced by 2 mug of either GP1 or GP4 was essentially identical in time course and pathology to that induced by whole testicular homogenates or 1 mug of purified acrosomal protein (AP1).