Patient Satisfaction with the Hybrid Telemedicine Model for Ophthalmology

Background: The purpose of this research was to compare patient satisfaction between hybrid ophthalmology telemedicine and standard-of-care in-person visits. A retrospective, cross-sectional, case-control analysis of patient satisfaction based on survey data was used. Methods: Responses to the National Research Council Health Patient Survey were retrieved for randomly sampled hybrid ophthalmology telemedicine and in-person visits between March 11, 2020 and December 31, 2021 at a hospital-based eye clinic in Boston, Massachusetts. The primary outcome was based on the question "How likely would you be to recommend this provider to your family and friends?" (0-10 scale) with a score of 9 or 10 coded as satisfied. Two-sample t-tests, Pearson's chi-square tests, and bivariate logistic regressions were used to compare patient satisfaction scores between the hybrid and in-person cohorts. Demographic data, including age, sex, language, and self-reported race and ethnicity, were used as potential predictors of patient satisfaction in a multivariable logistic regression model. Results: There were 49 surveys from hybrid visits and 3,390 surveys from in-person visits. Hybrid visit patients reported high satisfaction scores without significant differences compared to in-person visit patients (hybrid 79% satisfied, in-person 82% satisfied, p = 0.728). Age was significantly associated with satisfaction in the hybrid cohort with the 65+ age group reporting lower satisfaction (below 65 years 100% satisfied, 65+ years 60% satisfied, p = 0.003). No association with age was observed in the in-person cohort. Conclusions: The hybrid ophthalmology telemedicine model can provide effective care without sacrificing patient satisfaction. Older patients may benefit from targeted interventions in future telemedicine models.

Demographic and socioeconomic disparities in the hybrid ophthalmology telemedicine model

IMPORTANCE

As telemedicine use expands, it is important to evaluate demographic and socioeconomic disparities among patients receiving ophthalmic care through new hybrid telemedicine models.

OBJECTIVE

To evaluate whether there are demographic and socioeconomic disparities in the delivery of the hybrid telemedicine model.

DESIGN

Retrospective, cross-sectional, case-control analysis of patient encounters from April to December 2020.

SETTING

A single, academic, hospital-based eye clinic in Boston, Massachusetts.

METHODS

Electronic medical records of all patient encounters from April to December 2020 were reviewed and categorized into hybrid, virtual-only, and standard in-person visits. Patient-level data for all visits were extracted including age, sex, race/ethnicity, primary language, Area Deprivation Index (ADI), insurance type, and marital status. Visit-level data for all hybrid visits were also extracted from the medical record including the visit dates and patient adherence. Demographics for the cohort of patients with at least one no-show visit were compared with demographics for the cohort of patients who only had completed visits. The primary study outcomes were the differences in demographic characteristics between the hybrid visit show and no-show groups. The secondary outcomes included demographic characteristics of patients who did not complete their hybrid visit versus a time-matched cohort of patients who did not complete their standard in-person visit. Continuous variables for patient characteristics were compared with independent samples t-tests and categorical variables were compared using Pearson chi-square tests. Multivariate logistic regression was used to examine the differences between the cohorts. Variables with missing values other than suppressed ADI values were imputed using multiple imputations by chained equations.

RESULTS

Of a total of 1025 patients who were scheduled for a hybrid visit, 145 (14.1%) patients failed to complete their visit. Primary language and insurance were found to be statistically different between patients who completed and did not complete their hybrid visits. More English speakers and fewer Haitian Creole speakers completed their hybrid visits (p = 0.007) while more patients with private insurance and fewer patients with Medicaid completed their hybrid telemedicine visits (p = 0.026). No associations were found between hybrid telemedicine visit adherence and age, sex, race/ethnicity, marital status, or ADI. When the 145 patients who failed to complete their hybrid visits were compared to a time-matched cohort of patients who failed to complete their standard in-person visit, we found that patients who missed hybrid visits were similar to those who missed standard in-person visits except for patients insured by Medicare. These patients were more likely to miss a hybrid visit than a standard in-person visit (Odds Ratio 2.199, 95% confidence interval 1.136-4.259, p = 0.019). No associations were found between patient nonadherence with hybrid telemedicine versus with standard in-person visits based on age, sex, primary language, race/ethnicity, marital status, or ADI.

CONCLUSION

The hybrid telemedicine model was associated with insurance and language-based disparities. Patients with non-English primary language and Medicaid recipients were more likely to miss a hybrid visit than their counterparts. Our findings support developing deliberate interventions to ensure hybrid telemedicine care is delivered equitably to all patients.

Outcomes of a Hybrid Ophthalmology Telemedicine Model for Outpatient Eye Care During COVID-19

IMPORTANCE

The hybrid ophthalmology telemedicine model asynchronously pairs an imaging appointment by a technician with a subsequent virtual appointment by a clinician. Although it has been mentioned in several studies as an alternative to standard in-person care during the COVID-19 pandemic, outcomes of this alternative clinical care model remain to be evaluated.

OBJECTIVE

To investigate the outcomes associated with the hybrid ophthalmology telemedicine model during the COVID-19 pandemic for nonurgent and nonprocedural ophthalmological care.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective, cross-sectional study of all hybrid visits scheduled during the year 2020 in a single academic, hospital-based eye clinic in Boston, Massachusetts. All hybrid ophthalmology telemedicine visits completed in the year 2020 by opthalmologists and optometrists were included. Data were analyzed from January to December 2020.

EXPOSURES

Hybrid telemedicine clinical encounters.

MAIN OUTCOMES AND MEASURES

Four outcome metrics were calculated: (1) need for subsequent procedure visit, (2) medication change, (3) nonurgent, and (4) urgent consultation with another eye clinician. Adverse outcomes were defined as irreversible vision loss and the need for additional in-person evaluation to reach a management decision.

RESULTS

From April 9 to December 30, 2020, 889 patients (506 female patients [56.9%]; mean [SD] age, 62.1 [14.5] years; age range, 13-98 years) completed 940 hybrid visits. The most common visit indications were glaucoma (424 visits [45.1%]) and retinal diseases (499 visits [53.1%]). A total of 25 visits (2.7%) led to a procedure, 22 visits (2.3%) led to a change in medication, and 44 visits (4.7%) were referred for nonurgent consultation with another subspecialty with no instances of urgent referrals. Sixteen patients (1.7%) were referred to the on-call clinician for a same-day emergency in-person visit or recommended for a subsequent standard in-person visit to reach a management decision. There were no cases of irreversible vision loss following a hybrid visit.

CONCLUSIONS AND RELEVANCE

These findings suggest that with the appropriate patient selection and clinical setting, the hybrid ophthalmology telemedicine model may be a good alternative to standard in-person visits, particularly for patients with glaucoma and retinal diseases.

The severity and frequency distribution of endometriosis subtypes at different ages: a model to understand the natural history of endometriosis based on single centre/single surgeon data

Background and Objective

to study the natural history of endometriosis.

Materials and methods

the analysis of all women (n=2086) undergoing laparoscopy for pelvic pain and endometriosis between 1988 and 2011 at University Hospital Gasthuisberg.

Main outcome measures

the severity of subtle, typical, cystic and deep endometriosis in adult women, with or without a pregnancy, as estimated by their pelvic area and their volume.

Results

the number of women undergoing a laparoscopy increased up to 28 years of age and decreased thereafter. Between 24 and 44 years, the severity and relative frequencies of subtle, typical, cystic and deep lesions did not vary significantly. The number of women younger than 20 years was too small to ascertain the impression of less severe lesions. The severity of endometriosis lesions was not less in women with 1 or more previous pregnancies or with previous surgery. There was no bias over time since the type and severity of endometriosis lesions remained constant between 1988 and 2011.

Conclusions

severity of endometriosis does not increase between 24 and 44 years of age, suggesting that growth is limited by intrinsic or extrinsic factors. Severity was not lower in women with a previous pregnancy.

What is new

considering the time needed for lesions to become symptomatic together with the diagnostic delay, the decreasing number of laparoscopies after age 28 is compatible with a progressively declining risk of initiating endometriosis lesions after menarche, the remaining women being progessively less susceptible.

Nonvisualized palpable bowel endometriotic satellites

STUDY QUESTION

What is the prevalence of laparoscopically nonvisualized palpable satellite bowel nodules at or near the planned stapler site in women undergoing segmental bowel resection for endometriosis?

SUMMARY ANSWER

Overall, 13 (25.5%) of 51 patients who underwent resection had nonvisualized palpable satellite lesions as small as 2 mm, including seven (14%) who had nonvisualized palpable lesions at or beyond the planned stapler site.

WHAT IS KNOWN ALREADY

Both laparoscopy and laparotomy for bowel resection are standard of care in Europe and the USA. Reoperation rates after laparoscopic bowel procedures are 1–16%. Endometriotic lesions at the stapler margin of bowel resections are associated with increased repeat surgery. Nodules of 0.1 mm to 1 cm in size were not recognized during laparoscopic bowel surgery but were recognized on histological examination. Up to 20 nodules not visualized at laparoscopy have been recognized and excised at laparotomy. Tenderness is found at up to 27 mm from a recognized lesion. The size of a lesion does not always predict its symptoms or behavior.

STUDY DESIGN, SIZE, DURATION

This single-arm, observational study focused on the presence of nonvisualized palpable satellite lesions of the bowel. Fifty-one patients scheduled for laparoscopic-assisted bowel resection for deep infiltrating endometriosis with suprapubic incision for placement of the stapler’s anvil and removal of the specimen in the course of routine clinical care were included. There were no additional inclusion or exclusion criteria.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Laparoscopic-assisted segmental bowel resection for endometriosis was performed in a private referral center on women aged 24–49 years.

MAIN RESULTS AND THE ROLE OF CHANCE

Forty-nine (96.1%) of the 51 patients underwent segmental resection of the sigmoid or rectum, and 14 (27.5%) underwent segmental resection of the ileum for large nodule(s) recognized on MRI. Twelve patients underwent both procedures. Eleven (22.4%) of the 49 patients with recognized sigmoid or rectal lesions and 5 (35.7%) of the 14 patients with recognized ileal lesions had nonvisualized, palpable, satellite lesions. All the large lesions and none of the satellite lesions had been recognized preoperatively on MRI. Five (10%) of 49 patients with lesions of the large bowel and 4 (28.6%) of the 14 patients with lesions of the ileum had nonvisualized palpable satellite lesions at or beyond the planned stapler site. Lesions as small as 2 mm were palpable.

LIMITATIONS, REASONS FOR CAUTION

This is an observational study. It is not known if the small lesions of this study contributed to the symptoms or were progressive, stable or regressive. This study analyzed lesions in the bowel segment proximal to the primary large bowel lesion, but not in the distal segment as that would have required a change in standard of care surgical technique. This study protocol did not include shaving or disk resection or patients in whom no lesions were visualized. The use of additional techniques for recognition, such as hand-assisted laparoscopy or rectal probes, was not investigated.

WIDER IMPLICATIONS OF THE FINDINGS

This study confirms that some nonvisualized satellite lesions as small as 2 mm are palpable and that an increased length of resection can be used to remove lesions recognized by palpation and to avoid lesions at and beyond the stapler site. This may decrease recurrent surgery in 1–16% of the women undergoing surgery for bowel endometriosis. Knowledge of the occurrence of these small lesions may also be particularly useful in plans for repeat surgery or for women with clinically significant bowel symptoms and no visible lesions at laparoscopy. Moreover, small lesions are considered to be important as there is no current technique to determine whether a large primary lesion, smaller lesions, an associated adjacent tissue reaction or a combination of those cause symptoms.

STUDY FUNDING/COMPETING INTEREST(S)

This CIRENDO cohort was supported by the G4 Group (the University Hospitals of Rouen, Lille, Amiens and Caen) and the ROUENDOMETRIOSE association. No specific funding was received for the study. H.R. reports receiving personal fees from Plasma Surgical Inc., Ethicon Endosurgery, Olympus and Nordic Pharma for presentations related to his experience with endometriosis surgery. D.C.M. reports being given access to Lumenis Surgical CO₂ Lasers’ lab at a meeting. None of the other authors have conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER

N/A

Infection as a potential cofactor in the genetic-epigenetic pathophysiology of endometriosis: a systematic review

BACKGROUND

The genetic-epigenetic theory postulates that endometriosis is triggered by a cumulative set of genetic-epigenetic (GE) incidents. Pelvic and upper genital tract infection might induce GE incidents and thus play a role in the pathogenesis of endometriosis. Thus, this article aims to review the association of endometriosis with upper genital tract and pelvic infections.

METHODS

Pubmed, Scopus and Google Scholar were searched for 'endometriosis AND (infection OR PID OR bacteria OR viruses OR microbiome OR microbiota)', for 'reproductive microbiome' and for 'reproductive microbiome AND endometriosis', respectively. All 384 articles, the first 120 'best match' articles in PubMed for 'reproductive microbiome' and the first 160 hits in Google Scholar for 'reproductive microbiome AND endomytriosis' were hand searched for data describing an association between endometriosis and bacterial, viral or other infections. All 31 articles found were included in this manuscript.

RESULTS

Women with endometriosis have a significantly increased risk of lower genital tract infection, chronic endometritis, severe PID and surgical site infections after hysterectomy. They have more colony forming units of Gardnerella, Streptococcus, Enterococci and Escherichia coli in the endometrium. In the cervix Atopobium is absent, but Gardnerella, Streptococcus, Escherichia, Shigella, and Ureoplasma are increased. They have higher concentrations of Escherichia Coli and higher concentrations of bacterial endotoxins in menstrual blood. A Shigella/Escherichia dominant stool microbiome is more frequent. The peritoneal fluid of women with endometriosis contains higher concentrations of bacterial endotoxins and an increased incidence of mollicutes and of HPV viruses. Endometriosis lesions have a specific bacterial colonisation with more frequently mollicutes (54%) and both high and medium-risk HPV infections (11%). They contain DNA with 96% homology with Shigella. In mice transplanted endometrium changes the gut microbiome while the gut microbiome influences the growth of these endometriosis lesions.

CONCLUSIONS

Endometriosis is associated with more upper genital tract and peritoneal infections. These infections might be co-factors causing GE incidents and influencing endometriosis growth.

Correction: Heterogeneity of endometriosis lesions requires individualisation of diagnosis and treatment and a different approach to research and evidence based medicine

Statistical significance is used to analyse research findings and is together with biased free trials the cornerstone of evidence based medicine. However traditional statistics are based on the assumption that the population investigated is homogeneous without smaller hidden subgroups. The clinical, inflammatory, immunological, biochemical, histochemical and genetic-epigenetic heterogeneity of similar looking endometriosis lesions is a challenge for research and for diagnosis and treatment of endometriosis. The conclusions obtained by statistical testing of the entire group are not necessarily valid for subgroups. The importance is illustrated by the fact that a treatment with a beneficial effect in 80% of women but with exactly the same but opposite effect, worsening the disease in 20%, remains statistically highly significant. Since traditional statistics are unable to detect hidden subgroups, new approaches are mandatory. For diagnosis and treatment it is suggested to visualise individual data and to pay specific attention to the extremes of an analysis. For research it is important to integrate clinical, biochemical and histochemical data with molecular biological pathways and genetic-epigenetic analysis of the lesions.

Heterogeneity of endometriosis lesions requires individualisation of diagnosis and treatment and a different approach to research and evidence based medicine

Statistical significance is used to analyse research findings and is together with biased free trials the cornerstone of evidence based medicine. However traditional statistics are based on the assumption that the population investigated is homogeneous without smaller hidden subgroups. The clinical, inflammatory, immunological, biochemical, histochemical and genetic-epigenetic heterogeneity of similar looking endometriosis lesions is a challenge for research and for diagnosis and treatment of endometriosis. The conclusions obtained by statistical testing of the entire group are not necessarily valid for subgroups. The importance is illustrated by the fact that a treatment with a beneficial effect in 80% of women but with exactly the same but opposite effect, worsening the disease in 20%, remains statistically highly significant. Since traditional statistics are unable to detect hidden subgroups, new approaches are mandatory. For diagnosis and treatment it is suggested to visualise individual data and to pay specific attention to the extremes of an analysis. For research it is important to integrate clinical, biochemical and histochemical data with molecular biological pathways and genetic-epigenetic analysis of the lesions.

The Stone Cold Truth: The Effect of Concrete Encasement on the Rate and Pattern of Soft Tissue Decomposition

This study provides a descriptive analysis of taphonomic changes observed in the soft tissue of ten pigs (Sus scrofa) after being encased in Quickrete (®) concrete and excavated at monthly or bimonthly intervals over the course of 2 years. The best method of subject excavation was investigated. Rate and pattern of decomposition were compared to a nonencased control subject. Results demonstrate subjects interred in concrete decomposed significantly slower than the control subject (p < 0.01), the difference being observable after 1 month. After 1 year, the encased subject was in the early stage of decomposition with purging fluids and intact organs present, versus complete skeletonization of the control subject. Concrete subjects also display a unique decomposition pattern, exhibiting a chemically burned outer layer of skin and a common separation of the dermal and epidermal layers. Results suggest using traditional methods to estimate postmortem interval on concrete subjects may result in underestimation.

Lemonade from lemons: the taphonomic effect of lawn mowers on skeletal remains

This study provides a descriptive analysis of the taphonomic changes produced by passing over skeletonized remains (n = 4, Sus scrofa) with three common lawn mowers. Two skeletons were mowed over with a riding lawn mower set at multiple blade heights (10.16, 7.62, 5.08 cm) and one each with a rotary mower (9.53, 6.35 cm) and a mulching mower (6.35 cm). Results show that different types of common lawn mowers will produce different patterns of bone dispersal and fragmentation rates. Overall, skeletal elements projecting upward from the surface frequently exhibited a sheared morphology characterized by a smooth, flat, cut surface (7.0-7.6% of elements). The push mowers yielded a higher frequency of undamaged bone than the riding mower (54.8-61.2% vs. 17.7%), and the riding mower created more catastrophic damage to skeletal elements. Additionally, each mower produced a distinct dispersal pattern of skeletal fragments. The dispersal patterns have been identified as "bull's-eye" (riding), circular (mulching), and discontinuous rectangle (rotary).

Conduction Properties Of Decellularized Nerve Biomaterials

The purpose of this study is to optimize poly(3,4,-ethylenedioxythiophene) (PEDOT) polymerization into decellular nerve scaffolding for interfacing to peripheral nerves. Our ultimate aim is to permanently implant highly conductive peripheral nerve interfaces between amputee, stump, nerve fascicles and prosthetic electronics. Decellular nerve (DN) scaffolds are an FDA approved biomaterial (Axogen ) with the flexible tensile properties needed for successful permanent coaptation to peripheral nerves. Biocompatible, electroconductive, PEDOT facilitates electrical conduction through PEDOT coated acellular muscle. New electrochemical methods were used to polymerize various PEDOT concentrations into DN scaffolds without the need for a final dehydration step. DN scaffolds were then tested for electrical impedance and charge density. PEDOT coated DN scaffold materials were also implanted as 15-20mm peripheral nerve grafts. Measurement of in-situ nerve conduction immediately followed grafting. DN showed significant improvements in impedance for dehydrated and hydrated, DN, polymerized with moderate and low PEDOT concentrations when they were compared with DN alone (a ≤ 0.05). These measurements were equivalent to those for DN with maximal PEDOT concentrations. In-situ, nerve conduction measurements demonstrated that DN alone is a poor electro-conductor while the addition of PEDOT allows DN scaffold grafts to compare favorably with the "gold standard", autograft (Table 1). Surgical handling characteristics for conductive hydrated PEDOT DN scaffolds were rated 3 (pliable) while the dehydrated models were rated 1 (very stiff) when compared with autograft ratings of 4 (normal). Low concentrations of PEDOT on DN scaffolds provided significant increases in electro active properties which were comparable to the densest PEDOT coatings. DN pliability was closely maintained by continued hydration during PEDOT electrochemical polymerization without compromising electroconductivity.

Alcohol exposure in utero and functional deficits in children during the first four years of life

The behavioural effects of varying amounts of alcohol exposure in utero were studied using a longitudinal prospective design. An unselected sample of 1529 pregnant women was interviewed in the fifth month of pregnancy regarding beverage consumption, diet, drug use, and socioeconomic background; a cohort of approximately 500 infants was selected at delivery for follow-up. Lengthy individual behavioural and anthropometric examinations were made of the children between birth and four years of age. Alcohol-related behavioural effects are still statistically significant at four years, as they were at birth and eight months, even after adjustment for variables such as maternal smoking, drug use and diet, education, birth order and family stress. Habituation, sucking pressure and latency to suck are some of the behaviours most affected on days 1 and 2, while reaction time, attention and response latency are most affected at four years. Thus alcohol exposure in utero appears to affect the speed and accuracy of information-processing in the offspring. The findings support a dose-response rather than a threshold effect on most of these behavioural outcomes. However, increased risk of a clinically suspect or abnormal child occurs only at the heavier drinking levels. Examination of the cohort of 500 children at seven years of age is under way.

Müllerianosis

Müllerianosis may be defined as an organoid structure of embryonic origin; a choristoma composed of müllerian rests--normal endometrium, normal endosalpinx, and normal endocervix--singly or in combination, incorporated within other normal organs during organogenesis. A choristoma is a mass of histologically normal tissue that is "not normally found in the organ or structure in which it is located" (Choristoma, 2006). Müllerian choristomas are a subset of non-müllerian choristomas found throughout the body. Histologically, endometrial-müllerianosis and endometriosis are both composed of endometrial glands and stroma, but there the similarity ends. Their pathogenesis is different. Sampson faced the same difficulty with pathogenesis and nomenclature when he wrote: "The nomenclature of misplaced endometrial or müllerian lesions is a difficult one to decide upon." "The term müllerian would be inclusive and correct, but unfortunately it suggests an embryonic origin." Sampson then divided "misplaced endometrial or müllerian tissue" into "four or possibly five groups, according to the manner in which this tissue reached its ectopic location" (Sampson, 1925). Sampson's classification of heterotopic or misplaced endometrial tissue is based on pathogenesis: 1) "direct or primary endometriosis" [adenomyosis]; "a similar condition occurs in the wall of the tube from its invasion by the tubal mucosa" [endosalpingiosis]; 2) "peritoneal or implantation endometriosis;" 3) "transplantation endometriosis;" 4) "metastatic endometriosis;" and 5) "developmentally misplaced endometrial tissue. (I admit the possibility of such a condition, but have never been able to appreciate it.)" (Sampson, 1925). It is precisely this condition "developmentally misplaced endometrial tissue," [müllerianosis] that is the subject of this review.

Comparing methods to identify general internal medicine clinic patients with chronic heart failure

OBJECTIVES

Identification of patients with left ventricular systolic dysfunction is the first step in identifying which patients may benefit from clinical practice guidelines. The purpose of this study was to develop and validate a computerized tool using clinical information that is commonly available to identify patients with left ventricular systolic dysfunction (LVSD).

METHODS

We performed a cross-sectional study of patients seen in a Department of Veterans Affairs General Internal Medicine Clinic who had echocardiography or radionuclide ventriculography performed as part of their clinical care.

RESULTS

We identified 2246 subjects who had at least one cardiac imaging study. A total of 778 (34.6%) subjects met study criteria for LVSD. Subjects with LVSD were slightly older than subjects without LVSD (70 years vs 68 years, P =.00002) but were similar with regard to sex and race. Subjects with LVSD were more likely to have prescriptions for angiotensin-converting enzyme (ACE) inhibitors, carvedilol, digoxin, loop diuretics, hydralazine, nitrates, and angiotensin II receptor antagonists. Of the variables included in the final predictive model, ACE inhibitors, loop diuretics, and digoxin exerted the greatest predictive power. Discriminant analysis demonstrated that models containing pharmacy information were consistently more accurate (75% accurate [65% sensitivity, 81% specificity]) than those models that contained only International Classification of Diseases, 9th revision (ICD-9), codes, including ICD-9 codes for congestive heart failure (72% accurate [80% sensitivity, 68% specificity]).

CONCLUSIONS

We demonstrated that an automated, computer-driven algorithm identifying LVSD permits simple, rapid, and timely identification of patients with congestive heart failure by use of only routinely collected data. Future research is needed to develop accurate electronic identification of heart failure and other common chronic conditions.

Surface modification of neural recording electrodes with conducting polymer/biomolecule blends

The interface between micromachined neural microelectrodes and neural tissue plays an important role in chronic in vivo recording. Electrochemical polymerization was used to optimize the surface of the metal electrode sites. Electrically conductive polymers (polypyrrole) combined with biomolecules having cell adhesion functionality were deposited with great precision onto microelectrode sites of neural probes. The biomolecules used were a silk-like polymer having fibronectin fragments (SLPF) and nonapeptide CDPGYIGSR. The existence of protein polymers and peptides in the coatings was confirmed by reflective microfocusing Fourier transform infrared spectroscopy (FTIR). The morphology of the coating was rough and fuzzy, providing a high density of bioactive sites for interaction with neural cells. This high interfacial area also helped to lower the impedance of the electrode site and, consequently, to improve the signal transport. Impedance spectroscopy showed a lowered magnitude and phase of impedance around the biologically relevant frequency of 1 kHz. Cyclic voltammetry demonstrated the intrinsic redox reaction of the doped polypyrrole and the increased charge capacity of the coated electrodes. Rat glial cells and human neuroblastoma cells were seeded and cultured on neural probes with coated and uncoated electrodes. Glial cells appeared to attach better to polypyrrole/SLPF-coated electrodes than to uncoated gold electrodes. Neuroblastoma cells grew preferentially on and around the polypyrrole/CDPGYIGSR-coated electrode sites while the polypyrrole/CH(3)COO(-)-coated sites on the same probe did not show a preferential attraction to the cells. These results indicate that we can adjust the chemical composition, morphology, electronic transport, and bioactivity of polymer coatings on electrode surfaces on a multichannel micromachined neural probe by controlling electrochemical deposition conditions.

Regional variations in health status

CONTEXT

Knowledge about variations in the health status of patients seeking primary care in different parts of the United States is limited.

OBJECTIVE

To examine regional variations in the physical and mental health of patients receiving primary care in the largest integrated health care system in the United States which is operated by the Department of Veteran Affairs (VA).

STUDY DESIGN AND SETTING

We performed a mailed, cross sectional survey of 54,844 patients who were enrolled in seven VA General Internal Medicine clinics.

RESULTS

Among the 30,690 patients who returned an initial set of screening questionnaires, the prevalence of common chronic conditions varied by as much as 60% among the seven clinics. Moreover, patients' general health (measured by the SF-36) also varied significantly in a pattern that mirrored the observed differences in the prevalence of chronic conditions. After adjustment for important comorbid illnesses and sociodemographic factors, geographic site accounted for a small percentage of the explained variance in patient assessed health status.

CONCLUSIONS

The substantial differences in the health of patients enrolled in different VA primary clinics have important implications for the evaluation of clinical performance and health outcomes. Most of these differences can be attributed to sociodemographic and comorbid factors.

Surface characterization of porous, biocompatible protein polymer thin films

Genetically engineered protein polymer coatings are intended to improve the performance of implantable neural prosthetic devices. To facilitate device integration with tissue, three-dimensionally structured protein polymer films were deposited on the devices using electrostatic atomization and gas-evolution foaming. Periodic features and the length-scale dependence of the surface roughness were identified in topographic data collected using scanning probe microscopy. Using the power spectral density of surface data, the influence of process parameters on the surface roughness of protein polymer thin films was examined. Details of surface topography are known to influence biological behavior, and the method presented was capable of quantifying the evolution of surface features at biologically relevant length scales. This study provides a means for the quantitative exploration of the effects of topography on the performance of these devices and on biocompatibility in general.

Mechanisms of unresponsiveness associated with pretransplant blood transfusion-cyclosporine-induced mixed lymphocyte chimerism

Multiple pretransplant blood transfusions while under limited daily cyclosporine cover (PTBT-CsA) induce extensive rat renal allograft survival and antigen-specific non-responsiveness. The underlying mechanisms of this extensive allograft survival are not yet fully understood. We hypothesized that one of the potential contributing mechanisms to tolerance induction in PTBT-CsA-treated kidney recipients is the development of stable mixed chimerism, putatively due to the proliferation of stem cells capable of haematopoiesis in the transfused blood. BN rats served as whole blood and kidney donors. LEW rats served as recipients of the PTBT-CsA protocol and BN kidney transplants. Three weekly transfusions were given under concomitant limited CsA cover. Following these multiple primary sensitizations, antigen-specific splenic cellular responsiveness in vivo was normal in comparison with naive animals. However, these experimental splenocytes were non-specifically suppressed against third-party allodeterminants. At 100 days post-transplantation (T100) following tolerance induction to kidney allografts (secondary challenge), in vivo adoptive transfer experiments demonstrated the existence of potent splenic suppressor cells. In vitro suppressor cell assays confirmed that these cells were non-specific suppressor cells. However, following chimerism stabilization at T130, splenic antigen-specific suppressor cells became exclusively expressed in the tolerant animals, replacing the non-specific suppressor cells. At this time, splenic microchimerism was at peak levels and remained stable from T100 to T130. In conclusion, these findings demonstrate that sequential mechanisms of suppressor cell network expression are induced within a chimeric environment by blood-CsA immune modulation. Stable mixed lymphocyte chimerism and related immunomodulatory mechanisms may, therefore, play an important tolerogenic role in blood-CsA-induced non-responsiveness and in the beneficial effect of blood transfusion.

Increased tumor necrosis factor-alpha production by peripheral blood leukocytes from TCDD-exposed rhesus monkeys

Previous work has shown that exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is associated with a dose-dependent increase in the incidence and severity of endometriosis in the rhesus monkey. Studies also suggest that immune mechanisms participate in TCDD-mediated toxicity and the pathogenesis of endometriosis. Thirteen years after TCDD treatment was terminated, we characterized the phenotypic distribution of peripheral blood mononuclear cells (PBMC) from TCDD-exposed and -unexposed rhesus monkeys and determined the ability of these cells to produce cytokines and exert cytolytic activity against NK and T-cell-sensitive cell lines. We also determined whether elevated serum levels of TCDD, dioxin-like PHAH congeners, and triglycerides correlated with changes in PBMC phenotype or function. For all animals, TCDD exposure correlated with increased PBMC tumor necrosis factor-alpha (TNF-alpha) secretion in response to stimulation by T-cell mitogen and decreased cytolytic activity against NK-sensitive target cells. Furthermore, increased production of this cytokine by PHA-stimulated leukocytes was associated with elevated serum triglyceride levels. Leukocyte TNF-alpha secretion in response to viral antigen and PBMC production of interferon gamma (IFNgamma), IL-6, and IL-10 following exposure to mitogen or antigen were unaffected by previous TCDD treatment. Although TCDD exposure was not associated with changes in PBMC surface antigen expression, elevated serum concentrations of TCDD, 1,2,3,6,7,8-hexachlorodibenzofuran and 3,3',4,4',5-pentachlorobiphenyl correlated with increased numbers of CD3+/CD25- and CD3-/CD25+ leukocytes and enhanced secretion of TNF-alpha by mitogen-stimulated PBMC. These findings indicate that TCDD-exposed rhesus monkeys with endometriosis exhibit long-term alterations in systemic immunity associated with elevated serum levels of specific PHAH congeners.

Outcomes of pain center treatment in Washington State workers' compensation

BACKGROUND

Injured workers with chronic pain who have failed conventional therapies often receive treatment at pain centers. This study evaluated the effect of pain center treatment on time loss status of Washington State injured workers. The primary hypothesis was that treatment at a pain center would lead to a reduction in the probability of a worker's receiving time loss benefits at a 2-year follow-up.

METHODS

A population-based retrospective cohort study was performed on 2,032 Washington State workers' compensation patients who underwent pain center evaluations. Subjects who received pain center treatment were compared to those who were evaluated but not treated with respect to time loss status at 2-year follow-up.

RESULTS

Univariate analysis revealed that at 2-year follow-up, 35% of treated subjects were receiving time loss payments vs. 40% of evaluated only subjects (P < 0.05). Subjects who were younger, female, and less chronic were more likely to undergo pain center treatment and were less likely to be on time loss at 2-year follow-up. In multivariate analyses, which statistically controlled baseline differences between the two groups, there was no difference between treated subjects and evaluated only subjects.

CONCLUSIONS

There was no evidence that pain center treatment alters 2-year time loss status of already disabled workers.

Serum levels of TCDD and dioxin-like chemicals in Rhesus monkeys chronically exposed to dioxin: correlation of increased serum PCB levels with endometriosis

Humans and animals are exposed daily to a complex mixture of polyhalogenated aromatic hydrocarbons (PHAHs). Previous work has shown that exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is associated with a dose-dependent increase in the incidence and severity of endometriosis in the rhesus monkey. Dioxin-like chemicals can also exert effects in combination with TCDD via the aryl hydrocarbon receptor. This study demonstrates that the serum levels of TCDD and specific dioxin-like PHAH congeners were increased in TCDD-treated animals with endometriosis 13 years after the TCDD exposure. Nine TCDD-exposed and 6 unexposed female rhesus monkeys were evaluated for serum content of relevant compounds and for endometriosis by surgical laparoscopy. Additional studies were done on 4 animals that died 7 to 11 years after exposure to TCDD and 4 lead-treated animals with no history of PHAH treatment. For TCDD-exposed and unexposed animals, TCDD exposure correlated with an increased serum TCDD concentration. Furthermore, TCDD exposure and an elevated serum TCDD concentration were associated with increased serum levels of triglycerides, 1,2,3,6,7,8-hexachlorodibenzofuran, 3,3',4,4'-tetrachlorobiphenyl (TCB) and 3,3'4,4',5-pentachlorobiphenyl (PnCB). Importantly, the animals with elevated serum levels of 3,3',4,4'-TCB, 3,3',4,4',5-PnCB and an increased total serum TEQ had a high prevalence of endometriosis, and the severity of disease correlated with the serum concentration of 3,3,',4,4'-TCB. Increased serum concentrations of coplanar PCBs were also present in lead-treated animals. Implications of these findings for human health and the prevalence of endometriosis in humans will be discussed.

Injury death excesses in smokers: a 1990-95 United States national cohort study

OBJECTIVES

Assess injury death relative risks (RR), dose-response, and attributable fractions for current cigarette smokers (smokers) in a recent representative sample of the United States population without and with adjustment for (a) demographic and (b) additional behavioral risk factors.

SETTING

United States.

METHODS

National Health Interview Survey (NHIS) adult (ages 18+ years) interviewees from 1990 or 1991 were followed through 1995. Referents had never smoked a total of 100 cigarettes. Relative risks were estimated with Stata software's Cox proportional hazard regressions, using NHIS final weights and primary sampling units. The resulting RR and published data were used to estimate population smoking attributable fractions of injury deaths in the United States.

RESULTS

The crude, age-race-gender adjusted, and fully (demographic plus educational attainment, marital status, alcohol use level, and seat belt use) adjusted RRs for injury death in smokers were 1.86 (95% confidence interval (CI) 1.30 to 2.66), 1.60 (CI 1.12 to 2.29), and 1.42 (CI 0.99 to 2.05) respectively. Those RRs correspond to United States injury death smoking attributable fractions of 18%, 13%, and 9%, respectively. Those smoker/ injury death RRs each showed a significant dose response relationship (p<0.030). Smokers' unadjusted unintentional injury, motor vehicle crash, and suicide RRs were 1.87 (CI 1.22 to 2.86), 2.14 (CI 1.12 to 4.11), and 2.17 (CI 1.02 to 4.62), respectively.

CONCLUSIONS

Smokers in the United States have significant dose-response excesses of injury death, independent of age, race, gender, alcohol use, seat belt use, education, and marital status. This supports earlier studies suggesting that smoking may be a leading contributor to injuries and injury may be a leading burden from smoking, both nationally and globally.

Wrestling mats: are they a source of ringworm infections?

OBJECTIVE

To determine if the fungal molds (dermatophytes) responsible for causing ringworm could be isolated from a section of wrestling mat during the 1998-1999 season.

DESIGN AND SETTING

A 2-part study was conducted. The first phase involved a culture evaluation of material taken from wrestling mats at 8 local high schools. The second phase was a bench laboratory study to determine if the fungus and molds could be grown from a wrestling mat in an optimal setting.

SUBJECTS

We obtained material from areas of the practice mats of 8 high school wrestling teams at monthly intervals during the wrestling season. A 0.61-m (2-ft)x 0.31-m (1-ft) area of mat from 1 of the schools was used for the laboratory phase of the study.

MEASUREMENTS

We cultured samples taken from each school's wrestling mats for growth of dermatophytes and used a questionnaire to determine the mat-washing habits and policies of each school. Also, wrestlers from the 8 schools were screened weekly by the designated team physician and certified athletic trainer. Any suspicious lesions were cultured for fungi.

RESULTS

No dermatophytes were grown from the swab specimens taken at the 8 schools, and no dermatophytes were isolated from a section of mat evaluated in optimal laboratory conditions.

CONCLUSIONS

It is unlikely that wrestling mats are a source of ringworm infections in wrestlers.

Fire injuries, disasters, and costs from cigarettes and cigarette lights: a global overview

BACKGROUND

Fires cause 1% of the global burden of disease. Fire (includes explosion) disasters have immense health, social, and environmental costs. We will provide initial estimates of overall U. S. and global fire tolls from smoking.

METHODS

We tabulated and summarized smoking-related fire and disaster tolls from published documents. We compared those tolls to U.S. fire, burn, and fire death rates per billion cigarettes extrapolated globally. Smoking-attributable percentages of adult and child access to cigarette lighter and match ignitions (lights), and resultant fires, burns, and deaths ignited by young children, were estimated from likely smoking-attributable lights usage. Cigarette plus cigarette lights fire tolls were multiplied times published and estimated fire costs.

RESULTS

Smoking is the leading cause of residential or total fire death in all eight countries with available statistics. Smoking is a leading cause of fires in many more countries. Cigarettes cause numerous fire disasters. Cigarette lights cause an estimated 100,000 U.S. and one million global, child-playing fires per year. Cigarette lights fire injuries likely rival U.S., and possibly global, cigarette fire injury numbers. Smoking causes an estimated 30% of U. S. and 10% of global fire death burdens. Smoking's estimated U.S. and global fire costs were $6.95 (sensitivity range $5.34-22.8) and $27.2 (sensitivity range $8.2-89.2) billion, respectively, in 1998 U. S. dollars.

CONCLUSIONS

Smoking likely causes large global fire tolls. U.S. fire tolls have fallen when smoking decreased. Further reducing smoking can substantially reduce fire and disaster tolls.

Fluconazole for the prevention and treatment of tinea gladiatorum

BACKGROUND

Tinea gladiatorum is a common problem in competitive wrestling. It impacts on a wrestler's ability to compete. Several methods have been advocated to prevent these infections; however, no well-designed study of pharmacologic prophylaxis has been conducted.

METHODS

In a double blind placebo-controlled trial during the 1998 to 1999 regular wrestling season, wrestlers were randomized to receive 100 mg of fluconazole once weekly or placebo once weekly. Those not involved in the study were treated as a second control group. The effects of prophylaxis were also examined by assessing treatment of clinical infections with fluconazole 200 mg weekly for 4 weeks.

RESULTS

There was a significantly smaller incidence of infection in those given fluconazole (6%) than in those receiving placebo (22%) and those not involved in the prophylaxis phase (18%) (P<0.05). There was also a significant reduction in the total number of infections in the fluconazole group (P<0.05). Prophylaxis with fluconazole did not impact on the severity of disease, if contracted, when compared with the placebo prophylaxis participants who contracted tinea corporis. Of 21 wrestlers with tinea infections and positive cultures, 14 were able to have their isolates identified as Trichophyton tonsurans.

CONCLUSIONS

Fluconazole is effective and safe for primary prevention of tinea gladiatorum. We must now define when and in what population prophylaxis would be warranted.

Sonographic studies of human soleus and gastrocnemius muscle architecture: gender variability

The purpose of this study was to establish if there are gender differences in muscle architecture in relaxed human soleus and gastrocnemius muscles of normal, live subjects. Ultrasonography was used to measure fiber bundle length, muscle thickness, and angles of pennation in a total of ten predetermined sites in the medial and lateral heads of gastrocnemius and the anterior and posterior soleus in 19 males and 16 females. Percentage differences between males and females for each parameter were recorded. Gender differences were statistically analyzed using multivariate analysis of variance. In the gastrocnemius and soleus muscles of males and females the differences between the overall fiber bundle length, angle of pennation and muscle thickness were statistically significant (P < 0.05). Overall, females were found to have longer average muscle fiber bundle length and males thicker muscles and larger angles of pennation. The greatest percentage differences of the architectural parameters between males and females were in the posterior soleus: 13% difference in fiber length and 26% difference in angle of pennation in the midline of posterior soleus and 26% difference in muscle thickness of the lateral part of posterior soleus. No correlation was found between leg length and fiber length, angle of pennation or muscle thickness. Fiber length (decreased), angle of pennation (greater) and muscle thickness (greater) of most parts of the gastrocnemius and soleus muscles were significantly different in males and females. Leg length of males and females did not correlate to these architectural parameters.

Smoking as a risk factor for accident death: a meta-analysis of cohort studies

This meta-analysis discusses the consistency, strength, dose-response, independence, and generalizability of published cohort data on accident death relative risks in smokers. To locate data, three authors independently searched MEDLINE, and bibliographies of the pertinent studies found, for data which allowed estimation of an appropriate cigarette smoker accident death relative risk (and 95% confidence interval). Relative risks and dose-response were summarized by fixed effects and Poisson modeling, respectively. Four pertinent cohort studies including eight populations were located. Cigarette smoking predicted summary accident death relative risks of 1.51 (95% confidence interval 1.27-1.78) versus never smokers and 1.35 (1.17-1.57) versus ex-smokers. Summary dose-response trends were significant (P = 0.0000) versus never or least smoking referents. In individual studies, the smoking/accident death association persisted after adjustment or, in effect stratification, for age, race, sex, and occupation; occupation and time period; or numerous cardiac risk factors. This meta-analysis found significant, consistent, dose-response, often strong and independent (of age, race, and sex), prospective associations of smoking with accident death, internationally. Further studies and warnings of the smoking/accident death associations seem merited.

Estimates of smoking-attributable deaths at ages 15-54, motherless or fatherless youths, and resulting Social Security costs in the United States in 1994

BACKGROUND

Deaths of parents often harm their children, taxpayers, and society, for decades. So we estimated the smoking-attributable (SA) counts and percentages (SA%) of U.S. 1994 deaths at child-rearing ages; youths (ages <18) left motherless or fatherless; and resulting Social Security Survivors Insurance taxes.

DESIGN

U.S. 1994 age/sex/education-specific total and SA death counts were estimated using death certificate data and standard CDC SAMMEC methods (with added injury mortality), respectively. We separately summed (a) total and (b) SA age/sex/education-specific death counts times their average number of youths per adult (cumulative fertility, adjusted for infant mortality). We then multiplied the SA and total bereft youth counts by their average duration of Survivors Insurance, and calculated the SA cost of youth Survivors Insurance.

RESULTS

In 1994, smoking caused an estimated 44,000 male and 19,000 female U.S. deaths at ages 15-54, leaving 31,000 fatherless and 12,000 motherless youths. On December 31, 1994, the SA prevalences [count (SA%)] of fatherless or motherless youths were an estimated 220,000 (17%) and 86,000 (16%), respectively. Resulting Survivors Insurance costs were about $1.4 (sensitivity range: $0.58-3.7) billion in 1994.

CONCLUSIONS

Smoking causes many U.S. deaths at ages 15-54, youth bereavements, and Survivors Insurance costs. Reductions in smoking may greatly reduce those deaths, bereavements, and taxpayer and societal costs.

Chronic recording of regenerating VIIIth nerve axons with a sieve electrode

A micromachined silicon substrate sieve electrode was implanted within transected toadfish (Opsanus tau) otolith nerves. High fidelity, single unit neural activity was recorded from seven alert and unrestrained fish 30 to 60 days after implantation. Fibrous coatings of genetically engineered bioactive protein polymers and nerve guide tubes increased the number of axons regenerating through the electrode pores when compared with controls. Sieve electrodes have potential as permanent interfaces to the nervous system and to bridge missing connections between severed or damaged nerves and muscles. Recorded impulses might also be amplified and used to control prosthetic devices.

Resolution of subdiaphragmatic gas

A woman experienced dehydration, nausea, and vomiting after laparoscopic ovarian cystectomy. Symptoms resolved with hydration and observation. Daily abdominal radiographs revealed persistence of subdiaphragmatic gas for 7 days. There were no signs of peritonitis at any time during the evaluation. When patients experience abdominal complaints after laparoscopy, a major concern is perforated bowel. Since subdiaphragmatic air can persist for up to 24 days, clinical decisions are generally made on the basis of other findings.

Air embolus associated with tubal insufflation

A patient underwent laparoscopy for a rectovaginal mass, dysmenorrhea, and infertility. After CO(2) pneumoperitoneum was established the laparoscope was placed without difficulty. Before the procedure was completed, the tubes were insufflated with air through a 20-ml syringe attached to a Cohen cannula. Tubes were patent. No other intraabdominal manipulation was performed at that time. During tubal insufflation the patient's end-tidal CO(2) decreased to 18%, partial pressure of oxygen decreased to 83%, and pulse increased to 130/minute. The CO(2) pneumoperitoneum was released, and the woman stabilized spontaneously. The CO(2) pneumoperitoneum was again established, with no further difficulty. The time relationship with tubal insufflation and lack of recurrence on reestablishing pneumoperitoneum suggest that air embolization during tubal insufflation occurred.

Endometriosis and pain

Endometriosis generally causes pain that is cyclic and generally responds to medication and/or surgery. When endometriosis is found coincidentally, it may need no treatment because many women have endometriosis as a self-limited disease. In other women, the biologic behavior is much more unpredictable. Severe dysmenorrhea, focal pelvic tenderness, and deep dyspareunia are suggestive of endometriosis. Diagnosis at laparoscopy includes concerns about subtle appearance, endometriosis hidden within adhesions, retroperitoneal disease, and intra-ovarian lesions. Negative laparoscopy results do not mean that patients have no endometriosis. In contrast, a response to GnRH agonists can occur in patients with no endometriosis because conditions other than endometriosis are estrogen sensitive. Coexistent disease can confuse the picture at the time of surgery. Some coexistent diseases also can cause pain that is similar to that of endometriosis. Distinguishing those patients who need no treatment from those who need intermediate or extensive treatment can be very difficult. Care is needed to ensure that patients are neither overtreated or undertreated. An integrated approach involving a multidisciplinary team is needed in some. Other patients respond to primary care techniques.

Timp-1 is important for epithelial proliferation and branching morphogenesis during mouse mammary development

The dynamic process of mammary ductal morphogenesis depends on regulated epithelial proliferation and extracellular matrix (ECM) turnover. Epithelial cell-matrix contact closely dictates epithelial proliferation, differentiation, and survival. Despite the fact that tissue inhibitors of metalloproteinases (Timps) regulate ECM turnover, their function in mammary morphogenesis is unknown. We have delineated the spatiotemporal expression of all Timps (Timp-1 to Timp-4) during discrete phases of murine mammary development. Timp mRNAs were abundant in mammary tissue, each displaying differential expression patterns with predominant localization in luminal epithelial cells. Timp-1 mRNA was unique in that its expression was limited to the stage at which epithelial proliferation was high. To assess whether Timp-1 promotes or inhibits epithelial cell proliferation we manipulated mammary Timp-1 levels, genetically and biochemically. Down-regulation of epithelial-derived Timp-1 in transgenic mice, by mouse mammary tumor virus promoter-directed Timp-1 antisense RNA expression, led to augmented ductal expansion and increased number of ducts (P < 0.004). In these transgenics the integrity of basement membrane surrounding epithelial ducts, as visualized by laminin-specific immunostaining, was breached. In contrast to these mice, ductal expansion was markedly attenuated in the proximity of implanted recombinant Timp-1-releasing pellets (rTIMP-1), without an increase in basement membrane deposition around migrating terminal end buds. Epithelial proliferation and apoptosis were measured to determine the basis of altered ductal expansion. Luminal epithelial proliferation was increased by 55% (P < 0.02) in Timp-1-reduced transgenic mammary tissue and, conversely, decreased by 38% (P < 0.02) in terminal end buds by implanted rTIMP-1. Epithelial apoptosis was minimal and remained unaffected by Timp-1 manipulations. We conclude that Timps have an integral function in mammary morphogenesis and that Timp-1 regulates mammary epithelial proliferation in vivo, at least in part by maintaining basement membrane integrity.

Comparison of topical and oral treatments for tinea gladiatorum

OBJECTIVE

Little has been published regarding treatment guidelines for tinea gladiatorum in the competitive wresting population, where outbreaks are commonplace. This study compares the efficacy of a first-line topical treatment regimen and an oral treatment regimen.

DESIGN

A randomized, prospective, open-label pilot study was conducted during the 1997 to 1998 interscholastic wrestling season.

SETTING

Training rooms at two suburban high schools.

PARTICIPANTS

Male high school wrestlers with culture-proven tinea corporis were included in the study. There were 22 wrestlers enrolled; 17 finished the study.

INTERVENTIONS

Wrestlers were randomized to receive either clotrimazole 1% cream applied twice daily or fluconazole 200 mg once weekly for a total treatment duration of 3 weeks.

MAIN OUTCOME MEASURES

Symptom scores, lesion measurements, and fungal cultures were followed to assess treatment efficacy.

RESULTS

Eleven wrestlers received clotrimazole and six wrestlers finished the full course of fluconazole. The extrapolated time to 50% improvement in symptom scores was 11.9 days in the clotrimazole group and 10.1 days in the fluconazole group. The extrapolated time to 50% lesion reduction was 18.7 days in the clotrimazole group and 17.2 days in the fluconazole group. The extrapolated time to 50% culture eradication was 22.7 days in the clotrimazole group and 11.1 days in the fluconazole group.

CONCLUSION

Both clotrimazole and fluconazole produce similar improvement in clinical parameters. Fluconazole showed arithmetically, but not statistically, superior culture eradication. Fluconazole in a weekly dosing schedule should be considered in the first-line treatment of tinea gladiatorum.

Amino acid substitutions at the subunit interface of dimeric Escherichia coli alkaline phosphatase cause reduced structural stability

The consequences of amino acid substitutions at the dimer interface for the strength of the interactions between the monomers and for the catalytic function of the dimeric enzyme alkaline phosphatase from Escherichia coli have been investigated. The altered enzymes R10A, R10K, R24A, R24K, T59A, and R10A/R24A, which have amino acid substitutions at the dimer interface, were characterized using kinetic assays, ultracentrifugation, and transverse urea gradient gel electrophoresis. The kinetic data for the wild-type and altered alkaline phosphatases show comparable catalytic behavior with k(cat) values between 51.3 and 69.5 s(-1) and Km values between 14.8 and 26.3 microM. The ultracentrifugation profiles indicate that the wild-type enzyme is more stable than all the interface-modified enzymes. The wild-type enzyme is dimeric in the pH range of pH 4.0 and above, and disassembled at pH 3.5 and below. All the interface-modified enzymes, however, are apparently monomeric at pH 4.0, begin assembly at pH 5.0, and are not fully assembled into the dimeric form until pH 6.0. The results from transverse urea gradient gel electrophoresis show clear and reproducible differences both in the position and the shape of the unfolding patterns; all these modified enzymes are more sensitive to the denaturant and begin to unfold at urea concentrations between 1.0 and 1.5 M; the wild-type enzyme remains in the folded high mobility form beyond 2.5 M urea. Alkaline phosphatase H370A, modified at the active site and not at the dimer interface, resembles the wild-type enzyme both in ultracentrifugation and electrophoresis studies. The results obtained suggest that substitution of a single amino acid at the interface sacrifices not only the integrity of the assembled dimer, but also the stability of the monomer fold, even though the activity of the enzyme at optimal pH remains unaffected and does not appear to depend on interface stability.

Rate-determining step of Escherichia coli alkaline phosphatase altered by the removal of a positive charge at the active center

Escherichia coli alkaline phosphatase catalyzes both the nonspecific hydrolysis of phosphomonoesters and a transphosphorylation reaction in which phosphate is transferred to an alcohol via a phosphoseryl intermediate. The rate-determining step for the wild-type enzyme is pH dependent. At alkaline pH, release of the product phosphate from the noncovalent enzyme-phosphate complex determines the reaction rate, whereas at acidic pH hydrolysis of the covalent enzyme-phosphate complex controls the reaction rate. When the lysine at position 328 was substituted with a cysteine (K328C), the rate-determining step at pH 8.0 of the mutant enzyme was altered so that hydrolysis of the covalent intermediate became limiting rather than phosphate release. The transphosphorylation activity of the K328C enzyme was selectively enhanced, while the hydrolysis activity was reduced compared to that of the wild-type enzyme. The ratio of the transphosphorylation to the hydrolysis activities increased 28-fold for the K328C enzyme in comparison with the wild-type enzyme. Several other mutant enzymes for which a positive charge at the active center is removed by site-specific mutagenesis share this characteristic of the K328C enzyme. These results suggest that the positive charge at position 328 is at least partially responsible for maintaining the balance between the hydrolysis and transphosphorylation activities and plays an important role in determining the rate-limiting step of E. coli alkaline phosphatase.

Finite element modeling of banded structures in Bombyx mori silk fibres

Transmission electron microscopy studies have shown curved bands of contrast in degummed Bombyx mori fibres. This contrast implies a molecular difference between the light and dark bands, which in turn implies a periodic variation in mechanical properties along the fibre axis. Finite element modeling was used to compare the mechanical behaviour of fibres with various banded geometries. Lateral, longitudinal and diagonal lamellae were compared with V-shaped and parabolic cupped lamellae. The simulation results from the lamellar models were compared to laminar composite theory. The cupped parabolic and V-shaped geometrics both showed a redistribution of the axial stresses from the centre toward the edge of the fibre. This redistribution allowed for a substantial increase in the toughness compared to simple lateral lamella as well as a moderate increase in the initial modulus without a significant change in the yield strength.

Association between percutaneous transluminal coronary angioplasty volumes and outcomes in the Healthcare Cost and Utilization Project 1993-1994

Studies from a variety of settings have indicated that outcomes for coronary angioplasty are improved when performed in institutions with high caseloads (> 400/year). The purpose of this investigation was to examine the volume outcome hypothesis for coronary angioplasty in a 20% stratified sample of acute care, non-federal hospitals in 17 states. Data were derived from the Nationwide Inpatient Sample from the Health Care Cost and Utilization Project releases 2 and 3. From these records, 163,527 angioplasties from 214 hospitals were selected. Outcomes included hospital mortality, same-admission coronary artery bypass surgery, and a combined end point of either death or same-admission surgery, or both. Hospital volumes were defined as low (< or = 200 cases/year), medium (201 to 400), and high (> 400). Analyses were conducted separately for patients with and without a principal discharge diagnosis of acute myocardial infarction (AMI). For both AMI and no-AMI groups, the rates of adverse outcomes were generally lower in high-volume institutions, and this finding was true in both univariate and multivariate analyses. Although 27% of hospitals were in the low-volume category, only 5% of all procedures were performed in these institutions. Projecting to all United States hospitals for the 2 years, if all procedures performed in low-volume centers had been done in high-volume institutions, 137 deaths could have been averted (90 AMIs, 47 no-AMIs) as well as 404 (46 AMIs, 358 no-AMIs) same-admission surgeries. The results of this study support the hypothesis that better results are obtained in higher volume institutions, but also show that in 1993 and 1994, relatively few patients had their procedures performed in low-volume institutions.

Transgenic TIMP-1 inhibits simian virus 40 T antigen-induced hepatocarcinogenesis by impairment of hepatocellular proliferation and tumor angiogenesis

Tissue inhibitors of metalloproteinases (TIMP) block proteolytic degradation of extracellular matrix and consequently impede tumor invasion and metastasis. In addition, we have previously reported that hepatic TIMP-1 modulation alters the susceptibility of the liver to oncogene (simian virus 40 T-antigen; TAg)-induced tumorigenesis in a double-transgenic mouse model. To identify the cellular processes by which TIMP-1 inhibits hepatocarcinogenesis, we examined the effects of TIMP-1 on four specific events that are important during tumorigenesis: hepatocellular proliferation, apoptosis, the stromal characteristics of the liver, and tumor vascularization. Transgenic mice with elevated or reduced hepatic TIMP-1 expression were bred independently with TAg transgenics. Liver tissue from littermates were analyzed by in situ hybridization with TIMP-1 cDNA probes; gelatin enzymography; immunohistochemistry for proliferating cell nuclear antigen, von Willebrand factor, and collagen type IV; reticulin histochemistry; and collagens type III and IV, laminin, fibronectin, and CD31 immunoblotting. We demonstrate that TIMP-1 overexpression significantly inhibited the proliferation of hepatocytes in TAg mice but did not affect their apoptotic index, the hepatic parenchymal architecture, or extracellular matrix composition, including collagens type III and IV, laminin, and fibronectin. Moreover, the hepatocellular carcinomas formed in TIMP-1-overexpressing mice had significantly reduced tumor vascularization; conversely, tumor vascularization was significantly increased in TIMP-1-reduced livers. These data indicate that TIMP-1 inhibits TAg-induced hepatocarcinogenesis by altering hepatocellular proliferation and tumor vascularization, without any effect on hepatocyte apoptosis and stromal composition. To our knowledge, this is the first in vivo demonstration that genetic modulation of TIMP-1 inhibits cellular proliferation and angiogenesis during hepatocarcinogenesis. This potentially extends the use of matrix metalloproteinase inhibitors in cancer beyond control of invasion and metastasis.

Sodium lactate and hypertonic sodium chloride induce equivalent panic incidence, panic symptoms, and hypernatremia in panic disorder

BACKGROUND

Although experimental induction of panic by infusion of 0.5 mol/L sodium lactate in persons with panic disorder was described three decades ago, the mechanism underlying this observation remains unclear. Here we asked if the rapid administration of the large sodium load contained in the 0.5-mol/L sodium lactate infusion might be involved in panic induction.

METHODS

We compared in panic disorder and healthy subjects behavioral, electrolyte, endocrine, and acid-base responses to three double-blind randomly ordered equal volume 20-min infusions: 0.5 mol/L sodium lactate, hypertonic saline (3% sodium chloride), and normal saline placebo.

RESULTS

Sodium lactate (0.5 mol/L) and hypertonic saline produced the same high incidence of panic and equivalent increases in panic symptoms, serum sodium, and plasma vasopressin in the panic disorder subjects. Neither hypertonic infusion increased cortisol or adrenocorticotropin. No normal subject experienced panic in any condition. The 0.5-mol/L sodium lactate infusion induced alkalosis, whereas hypertonic saline and normal saline induced a mild acidosis.

CONCLUSIONS

Hypertonic sodium solution containing either chloride or lactate anion induces panic in panic disorder. The large sodium loads delivered by hypertonic saline and 0.5 mol/L sodium lactate may be involved in the mechanism of panic induction.

Smoking as a risk factor for injury death: a meta-analysis of cohort studies

BACKGROUND

Injury and tobacco effects represent one-quarter of the global burden of disease. Understanding the causes of injury and the effects of smoking may help reduce those burdens. Some smokers have high risks of injury. We provide an initial meta-analysis of cohort associations between smoking and fatal injury.

METHODS

Three authors independently searched MEDLINE, and bibliographies of the pertinent studies found, for cigarette smoker-specific injury death data which allowed estimation of an appropriate relative risk (RR) and 95% confidence interval (CI). Relative risks and dose response were summarized by fixed effects and Poisson modeling, respectively.

RESULTS

Six studies covering 10 pertinent cohorts were located. Associations between smoking and injury death have been significant after adjustment or, in effect, stratification for age, race, sex, country, and, respectively, alcohol, marriage, education, and body mass; job and time period; job, alcohol, and exercise; etc. Summary dose-response trends were significantly positive (P < 0.00005). Cigarette smoking predicted summary injury death crude RRs of 1.61 (CI 1.44-1.81) vs never smokers and 1.39 (CI 1.25-1.55) vs ex-smokers.

CONCLUSIONS

Smoking has significant, consistent, dose-response, often strong and independent, prospective associations with injury death, internationally.

Perceived efficacy of pain clinics in the rehabilitation of injured workers

OBJECTIVE

To assess the perceived efficacy of pain clinics in the rehabilitation of injured workers among four groups of professionals.

DESIGN

A questionnaire was given to 351 subjects representing four professional groups: physicians, vocational rehabilitation counselors, staff at pain clinics, and employees of a workers compensation program. Subjects rated the effectiveness of pain clinics in eight specific functions, estimated the percentage of workers who return to work after pain clinic treatment, and indicated how soon after injury a worker should be referred to a pain clinic.

RESULTS

Pain clinic staff consistently gave the most favorable ratings and workers compensation employees the least favorable ones. There was good agreement across professional groups regarding the need for early referral of injured workers to pain clinics and the specific functions that pain clinics carry out relatively well. Clinics were ranked as most effective in reducing workers' use of opiates, and as least effective in reducing workers' pain. Return-to-work estimates varied significantly across professional groups. Within professional groups, subjects with high estimates gave more favorable overall ratings to pain clinics.

CONCLUSIONS

The results provide a profile of the perceived effectiveness of pain clinics in various functions and highlight the importance of getting accurate information about return to work rates following pain clinic treatment. They suggest that workers are not referred to pain clinics early enough.

Immunoassay of human Neisseria meningitidis serogroup A antibody

An enzyme immunoassay is described which quantitates antibodies to Neisseria meningitidis serogroup A capsular polysaccharide in human sera. Modifications of a previously developed two-day assay by Carlone et al. were made to permit analysis in one day and to be compatible with automation. The allowable variations in assay conditions and the areas in which stringent control must be maintained for consistent assay performance are described. Antigen-coating parameters, the kinetics of primary and secondary antibody incubation steps, the buffer compositions, including detergents, serum requirements, and the need for blocking steps were examined. Our modified one-day assay showed excellent agreement with the standardized method of Carlone, with a correlation coefficient between the two methods of 0.989. This assay is adaptable within a permissible range of parameters thus facilitating the implementation of the standardized assay. This will maximize the consistency of results from serum analysis for conjugate vaccine trials related to serotype A Neisseria meningitidis.

Host TIMP-1 overexpression confers resistance to experimental brain metastasis of a fibrosarcoma cell line

Within the tumor-stromal microenvironment a disrupted balance between matrix metalloproteinases (MMPs) and their inhibitors compromises the integrity of the extracellular matrix and promotes malignancy. Tissue inhibitors of metalloproteinases (TIMPs) have been linked to tumor suppression in studies of genetically altered tissue culture cells and in analyses of clinical specimens in situ. We generated transgenic mice as a model system to test the relationship between TIMP-1 levels in a host organ and susceptibility to experimentally targeted metastasis. Ectopically overexpressed TIMP-1 in the brain resulted in a tissue microenvironment with elevated protein levels of this natural MMP inhibitor. Metastatic challenge provided by lacZ-tagged fibrosarcoma cells permitted high-resolution analysis of metastatic load and pattern. We found that elevated host TIMP-1 imposed resistance to experimental metastasis of fibrosarcoma: In TIMP-1 overexpressing mice, brain metastases were significantly reduced by 75% compared to wild-type littermates. Our findings demonstrate that ectopic TIMP-1 expression efficiently exerts a suppressive effect on metastasizing tumor cells.