Trends in the incidence and mortality of infective endocarditis in high-income countries between 1990 and 2019.

BACKGROUND: Infective endocarditis (IE) remains a life-threatening disease with high morbidity and mortality. OBJECTIVES: To describe temporal trends in IE incidence, mortality and survival over the last 30 years. METHODS: Nineteen high-income countries (the 'EU 15+') were included. Age-standardised and sex-stratified incidence rates (ASIRs) and mortality rates (ASMRs) for IE were extracted from the Global Burden of Disease (GBD) database between 1990 and 2019, and mortality to incidence ratios (ASMIRs) were calculated. Trends were analysed using Joinpoint regression analysis. RESULTS: ASIRs were higher in males than females and increased in both sexes in all countries between 1990 and 2019. A recent steep rise in ASIRs was noted in several countries including the UK, the USA and Germany. ASMRs increased for both sexes in all countries except Finland and Austria. The largest increase in ASMR was observed in females in Italy (+246%). ASMIRs were generally higher in females compared to males, with large increases in ASMIRs (indicating worsening survival) at the end of the 20th century, but more recent stabilisation or decline across the study cohort. CONCLUSIONS: While the incidence and mortality of IE have increased over the last 30 years, recent data suggest that these trends have plateaued or reversed in most countries studied. However, a recent surge in incidence in several countries (including the USA and UK) is of concern, while unfavourable outcomes in females also merit attention. More encouragingly, this analysis provides the first indication of improving IE survival at population level, supporting recent advances in diagnosis and treatment.

A two-step risk assessment method for radiofrequency ablations of spine metastases.

BACKGROUND: Spine metastases (MTS) can be treated via Radiofrequency Ablation (RFA) electrodes. To bring these electrodes into vertebral MTS, pathways have to be created. This can be done via transpedicular hammering or drilling. However, this is challenging due to spatial constraints, and because MTS can alter bone density considerably. METHOD: In this work a two-step method is presented that intends to offer cognitive and physical assistance. Step 1 comprises two visualization methods that depict safety margins between and in risk structures. For Step 2, the correlation between Hounsfield Units (HUs) and drilling forces was analyzed to support manual and robot-assisted RFAs. RESULTS: In-depth descriptions of two clinical cases and detailed feedback from the local clinic of neuroradiology are used to present the capabilities of the proposed method. Furthermore, a stiffness criterion is presented to predict drilling force changes from the local distribution and homogeneity of HUs with an inaccuracy of less than 1 mm. CONCLUSIONS: The combination of visualization and drilling force prediction shows potential to support manual and robot-assisted spine RFAs. However, limitations have to be addressed in the future. For example, it has to be carefully evaluated to which extent the proposed method can speed up the planning process and increase intervention safety.

Apparent Diffusion Coefficient Histograms of Human Papillomavirus-Positive and Human Papillomavirus-Negative Head and Neck Squamous Cell Carcinoma: Assessment of Tumor Heterogeneity and Comparison with Histopathology.

BACKGROUND AND PURPOSE: Head and neck squamous cell carcinoma associated with human papillomavirus infection represents a distinct tumor entity. We hypothesized that diffusion phenotypes based on the histogram analysis of ADC values reflect distinct degrees of tumor heterogeneity in human papillomavirus-positive and human papillomavirus-negative head and neck squamous cell carcinomas. MATERIALS AND METHODS: One hundred five consecutive patients (mean age, 64 years; range, 45-87 years) with primary oropharyngeal (n = 52) and oral cavity (n = 53) head and neck squamous cell carcinoma underwent MR imaging with anatomic and diffusion-weighted sequences (b = 0, b = 1000 s/mm2, monoexponential ADC calculation). The collected tumor voxels from the contoured ROIs provided histograms from which position, dispersion, and form parameters were computed. Histogram data were correlated with histopathology, p16-immunohistochemistry, and polymerase chain reaction for human papillomavirus DNA. RESULTS: There were 21 human papillomavirus-positive and 84 human papillomavirus-negative head and neck squamous cell carcinomas. At histopathology, human papillomavirus-positive cancers were more often nonkeratinizing (13/21, 62%) than human papillomavirus-negative cancers (19/84, 23%; P = .001), and their mitotic index was higher (71% versus 49%; P = .005). ROI-based mean and median ADCs were significantly lower in human papillomavirus-positive (1014 ± 178 × 10-6 mm2/s and 970 ± 187 × 10-6 mm2/s, respectively) than in human papillomavirus-negative tumors (1184 ± 168 × 10-6 mm2/s and 1161 ± 175 × 10-6 mm2/s, respectively; P < .001), whereas excess kurtosis and skewness were significantly higher in human papillomavirus-positive (1.934 ± 1.386 and 0.923 ± 0.510, respectively) than in human papillomavirus-negative tumors (0.643 ± 0.982 and 0.399 ± 0.516, respectively; P < .001). Human papillomavirus-negative head and neck squamous cell carcinoma had symmetric normally distributed ADC histograms, which corresponded histologically to heterogeneous tumors with variable cellularity, high stromal component, keratin pearls, and necrosis. Human papillomavirus-positive head and neck squamous cell carcinomas had leptokurtic skewed right histograms, which corresponded to homogeneous tumors with back-to-back densely packed cells, scant stromal component, and scattered comedonecrosis. CONCLUSIONS: Diffusion phenotypes of human papillomavirus-positive and human papillomavirus-negative head and neck squamous cell carcinomas show significant differences, which reflect their distinct degree of tumor heterogeneity.

[The regional network ADAPTHERA : Rheumatology care through coordinated cooperation: comprehensive, trans-sectoral, covering all health insurance. Initial results]. / Das landesweite Netzwerk ADAPTHERA : Erste Ergebnisse einer flächendeckenden, krankenkassenübergreifenden und transsektoralen rheumatologischen Versorgung.

The aim of the rheumatology network ADAPTHERA ("risk-adapted rheumatology therapy") is to achieve a comprehensive improvement in rheumatology care by coordinating treatment in a regional, trans-sectoral network. Accompanying biomedical research projects, training concepts, and the construction of a rheumatology register (gathering data and biomaterials) should furthermore ensure the stable and sustainable optimisation of care. In the pilot phase (2012-2015) the focus of the ADAPTHERA network, required as a "regional key project" within the framework of the Initiative on Health Economy of Rheinland-Palatinate (RL-P), Germany, was placed on the optimisation of the early diagnosis of rheumatoid arthritis, where it is well-known that there is a significant care deficit.Through the intensive, stable, and coordinated cooperation of all health care partners in the field of rheumatology (registered general practitioners and orthopaedic specialists, registered core rheumatologists as well as the Association of Rheumatology of RL-P) a unique regional, comprehensive offer with verifiable care optimisation has been established in RL-P. The network is supported by outstanding collaboration with the Association of Statutory Health Insurance Physicians and the self-help organisation Rheumatology League.The aims that were established at the start of the project will be achieved by the end of the pilot phase:- significant improvement in the early diagnosis of rheumatoid arthritis (an average of 23.7 days until diagnosis by rheumatologists)- access covering all health insurance (regardless of the particular scheme the patients belong to)- comprehensive (verifiable participation of general practitioners from all over RL-P)- data and biomaterials collection, established as a basis for biomarker research, and a rheumatology register for RL-P.

[Provision of outpatient specialist care for mental disorders : Minor regional differences in treatment needs, major regional differences in availability]. / Ambulante fachärztliche Versorgung psychischer Störungen : Kleine regionale Unterschiede im Bedarf, große regionale Unterschiede in der Versorgungsdichte.

BACKGROUND: Due to the high burden attributed to mental disorders, an important purpose of a general healthcare system is to provide comprehensive medical specialist care that is both locally available and in line with demand; however, the density of outpatient physicians and psychotherapists significantly varies between regions in Germany. To verify if these variations reflect regional variations of morbidity rates, routine data of statutory health insurance companies are analyzed on a regular basis. But these administrative data directly depend on the actual regional health care supply. Hence, independent epidemiological data on prevalence rates of mental disorders could be a valuable supplement. METHODS: Analyses are based on prevalence rates of the representative epidemiological German health interview and examination survey and its mental health module (DEGS1-MH) as well as supplemental data from the German national and regional associations of statutory health insurance physicians. The associations between prevalence rates and density of outpatient physicians and psychotherapists were computed for the DEGS sample points, representing 139 different German districts. Transregional care provision for neighboring regions was taken into account. RESULTS: There were neither significant associations of regional density of outpatient physicians and psychotherapists with prevalence rates of mental disorders in general nor with prevalence rates of severe mental disorders; however, taking into account transregional care provision for neighboring regions the huge variability of provider density decreases. DISCUSSION: The regional inequality of physician and psychotherapist density cannot be explained by regional differences in treatment needs. The results indicate potential improvements in healthcare provision for mental disorders in Germany through the adaptation to actual morbidity rates; however, the definition of treatment needs in mental disorders requires further evaluation.

Measurement of wheelchair contact force with a low cost bench test.

In mechanical engineering, it is well established that contact between the tire and the ground is a key parameter in characterizing the dynamic behavior of vehicles and an important factor in design control. Therefore, it is an important part of dynamic simulation models for vehicles, including wheelchairs. This work presents a bench test designed to experimentally monitor and measure the forces transmitted to the ground by a moving wheel. The test bench is composed of a table and a track with a fixed wheel structure and powertrain system. The table is an integrated structure that measures the longitudinal and lateral forces produced by tire contact. This table allows characterization of the tire and tests the tire under varying loads at different slip and camber angles. Additionally, the test bench can also be used to evaluate other tires, such as caster tires. The performances of the new device are illustrated, and the results show the differences between tires, which are related to the dynamic behaviors of wheelchair model. Finally, preliminary experiments performed using the test bench have shown that it is able to monitor and measure the forces generated by the contact between the tire and the ground.

Safety assessment of [3S, 3'S]-astaxanthin--Subchronic toxicity study in rats.

Astaxanthin, a naturally occurring xanthophyll, is commercially used as a coloring agent in salmon feed, but also marketed as a dietary supplement. The objective of this study was to investigate the subchronic toxicity of synthetic [3S, 3'S]-Astaxanthin in rats. A powder formulation containing approximately 20% [3S, 3'S]-Astaxanthin was administered via the diet to groups of 10 male and 10 female Wistar rats at concentrations of 5000, 15,000 and 50,000 ppm for a period of 13 weeks. A formulation of comparable composition but without [3S, 3'S]-Astaxanthin served as a placebo control. There were no effects observed on survival, clinical examinations, clinical pathology, estrous cycle as well as on sperm parameters. At terminal necropsy, a macroscopically visible brown-blue discoloration of the gastrointestinal contents was noted which was considered to be secondary to the violet-brown color of the test material. No other significant or dose-related abnormalities were found in the tissues collected at termination. Our observations support that ingestion of [3S, 3'S]-Astaxanthin of up to 700-920 mg/kg bw/day in rats in a gelatin/carbohydrate formulation is without adverse effects.

Dual-energy CT-based assessment of the trabecular bone in vertebrae.

BACKGROUND: Osteoporosis can cause severe fractures of bone structures. One important indicator for pathology is a lowered bone mineral density (BMD) - conventionally assessed by dual-energy X-ray absorptiometry (DXA). Dual-energy CT (DECT) - being an alternative that is increasingly used in the clinics - allows the computation of the spatial BMD distribution. OBJECTIVES: Using DECT, the trabecular bone of vertebrae is examined. Several analysis methods for revealing the bone density distribution as well as appropriate visualization methods for detecting regions of lowered BMD are needed for computer-assisted diagnosis (CAD) of osteoporosis. The hypothesis that DECT is better suited than DXA for the computation of local BMD is investigated. METHODS: Building on a model of the interaction of X-rays with bone tissue, novel methods for assessing the spatial structure of the trabecular bone are presented. CAD of DECT image data is facilitated by segmenting the regions of interest interactively and with an Active Shape Model, respectively. The barycentric space of fractional volumes is introduced as a novel means for analyzing bone constitution. For 29 cadaver specimens, DECT as well as DXA has been examined. BMD values derived from both modalities are compared to local force measurements. In addition, clinical data from two patients who underwent DECT scanning for a different reason is analyzed retrospectively. RESULTS: A novel automated delineation method for vertebrae has been successfully applied to DECT data sets. It is shown that localized BMD measurements based on DECT show a stronger linear correlation (R² = 0.8242, linear regression) to local force measurements than density values derived from DXA (R² = 0.4815). CONCLUSIONS: DECT based BMD assessment is a method to extend the usage of increasingly acquired DECT image data. The developed DECT based analysis methods in conjunction with the visualization provide more detailed information for both, the radiologist and the orthopedist, compared to standard DXA based analysis.

A dedicated cardioversion unit for the treatment of atrial fibrillation. Reducing costs by optimizing processes.

BACKGROUND: Atrial fibrillation (AF) is the most frequent arrhythmia seen in man. Many patients are admitted to the hospital to undergo transesophageal echocardiography (TEE) for thrombus exclusion and subsequent electrical cardioversion (ECV) under deep sedation to restore sinus rhythm. The present study investigated prospectively how workflow optimization can contribute to reducing time and costs in AF patients scheduled for ECV in an outpatient setting. METHODS: A cardioversion unit (CU) was established and equipped to perform all ECV-associated procedures. Between November 2007 and January 2009, ECV was performed in 115 patients in an outpatient setting. Three different settings were tested for ECV: (1) usual care (n = 19): preparation/follow-up in the outpatient clinic, blood testing in the central hospital laboratory (CHL), TEE in the echocardiography laboratory, and ECV in the intensive care unit; (2) optimized process 1 (n = 41): preparation/follow-up, TEE + ECV during one sedation in the CU, blood testing in the CHL; (3) optimized process 2 (n = 55): preparation/follow-up, TEE + ECV and point of care (POC) blood testing in the CU. All procedure-related costs were listed and classified according to material, human resources, and infrastructure. RESULTS: From setting 1 to 3, there was a significant decrease in procedural time from 480 ± 105 min to 205 ± 85 min (p < 0.001). Likewise, ECV-associated costs could be reduced from 683 ± 104  to 299 ± 63  (p < 0.001). CONCLUSION: Establishing a CU for AF enables a more than 50% reduction in procedural time and costs. A combination of TEE and ECV in one sedation and POC testing in the CU were the major contributors to this time and cost reduction.

[Antibiotics in elderly patients: Impact of clinical practice evaluation]. / Antibiothérapie chez le sujet âgé : impact d'une démarche d'évaluation des pratiques professionnelles.

OBJECTIVE: Improving the use of antimicrobial drugs is a national objective. To this end an evaluation of clinical practice was implemented on prescribed antibiotics in elderly patients, in the Besançon Teaching Hospital. DESIGN: In 2005, a clinical audit compared the adequacy of antibiotic prescriptions to national guidelines in 37 patients. An improvement plan was implemented, including the drafting of local guidelines (adapted national guidelines) "Antibiotic prescription in elderly patients" by a multidisciplinary team. The Antibiotics Committee approved it. A retrospective study compared antibiotic prescription of 62 patients to these guidelines. The methodology was based on Gyssen's algorithm. The assessment criteria were: relevance of the indication, absence of a better alternative, respect of recommended dose, duration, and timing. RESULTS: The rate of overall conformity was 26% in 2005, 57% in 2007. Antibiotic choice was adequate in 61% of cases in 2005, 78% in 2007. In 63% of cases, a more efficient alternative was advised in 2005, 10% of cases in 2007. Treatment duration, dose, and timing were adequate in 54 - 92 - 96% in 2005 respectively and 86 - 92 - 100% of cases in 2007. Ciprofloxacin was prescribed in first line for 42% of urinary infections in 2005, 0% in 2007. CONCLUSIONS: This approach improved antibiotic prescriptions because of better guideline observance by physicians. The main improvement concerned fluoroquinolones. It should be continued to confirm antibiotic good use and protect our hospital bacterial ecology.

Magnetic resonance imaging in the quantitative assessment of gouty tophi.

Measurements of tophus size can be important in monitoring the course of gout therapy, as tophus resolution is proposed as one measure of success of treatment. This multicentre study assessed the intra- and interreader reproducibility of quantitative tophus volume measurements from magnetic resonance images (MRI) in subjects with palpable gouty tophi. Subjects first underwent radiographic imaging of a selected tophus followed by MRI before and at

[Diagnostic procedure for uveitis patients: reduction of costs by a targeted assessment of laboratory tests based on clinical findings]. / Abklärung bei Uveitis: Kostenreduktion durch befundorientiertes diagnostisches Vorgehen.

BACKGROUND: Interdisciplinarity is an essential prerequisite for extensive and high-quality diagnostic work-up, therapy, and care of patients with inflammatory rheumatic disease. The ophthalmological status significantly narrows down the possible causes for the primary disease and facilitates an effective diagnostic approach. METHODS: We developed an assessment procedure according to the individual clinical findings to use as an ideal diagnostic strategy for an interdisciplinary center. To permit comparability we first introduced this new diagnostic tool in November 2002 (intervention), replacing the existing cost-intensive standard diagnostic procedure for uveitis patients. RESULTS: The average costs for laboratory tests (calculated according to GOA numbers, scale of fees for physicians) were reduced from 670+/-11 euros per patient before the intervention to 238+/-18 euros per patient after the intervention. Before intervention 16 of 31 (52%) could be assigned to a specified disease compared to 27 of 53 (51%) after the intervention. With our strategy we were able to obtain a 64% reduction of costs in the diagnostics of uveitis patients without a deterioration of our diagnostic quality. CONCLUSION: It is possible to reduce costs and still improve the care of uveitis patients by using a targeted assessment according to the individual clinical findings.

Analysis of myocardial deformation based on pixel tracking in two dimensional echocardiographic images enables quantitative assessment of regional left ventricular function.

OBJECTIVE: To evaluate whether myocardial strain and strain rate calculated from two dimensional echocardiography by automatic frame-by-frame tracking of natural acoustic markers enables objective description of regional left ventricular (LV) function. METHODS: In 64 patients parasternal two dimensional echocardiographic views at the apical, mid-ventricular and basal levels were obtained. An automatic frame-by-frame tracking system of natural acoustic echocardiographic markers was used to calculate radial strain, circumferential strain, radial strain rate and circumferential strain rate for each LV segment in a 16 segment model. Cardiac magnetic resonance imaging (cMRI) was performed to define segmental LV function as normokinetic, hypokinetic or akinetic. RESULTS: Image quality was sufficient for adequate strain and strain-rate analysis from two dimensional echocardiographic images obtained from parasternal views in 88% of segments. Obtained radial strain data were highly reproducible and analysis was affected by only small intraobserver (mean 4.4 (SD 1.6)%) and interobserver variabilities (7.3 (2.5)%). Each of the analysed strain and strain-rate parameters was significantly different between segments defined as normokinetic, hypokinetic or akinetic by cMRI (radial strain 36.8 (10.5)%, 24.1 (7.5)% and 13.4 (4.8)%, respectively, p < 0.001). Peak systolic radial strain enabled detection of hypokinesis or akinesis with a sensitivity of 83.5% and a specificity of 83.5% (cut off value 29.1%, receiver operating characteristic (ROC) curve area 0.905, 95% CI 0.883 to 0.923). Peak systolic radial strain analysis also enabled detection of akinesis versus hypokinesis with a sensitivity of 82.7% and a specificity of 94.5% (cut off value 21.0%, ROC curve area 0.946). Peak systolic radial strain-rate analysis was less accurate than peak systolic radial strain analysis to detect cMRI-defined segmental function abnormalities. The accuracy of peak systolic circumferential strain and strain rate was similar to that of corresponding radial parameters. CONCLUSIONS: Frame-by-frame tracking of acoustic markers in two dimensional echocardiographic images enables accurate analysis of regional systolic LV function.

Direct assessment and distribution of regional portal blood flow in the pig by means of fluorescent microspheres.

Measurement of regional organ blood flow by means of fluorescent microspheres (FM) is an accepted method. However, determination of regional portal blood flow (RPBF) cannot be performed by microspheres owing to the entrapment of the spheres in the upstream capillary bed of the splanchnic organs. We hypothesized that an adequate experimental setting would enable us to measure RPBF by means of FM and to analyze its distribution within the pig liver. A mixing chamber for the injection of FM was developed, and its capability to distribute FM homogeneously in the blood was evaluated in vitro. The chamber was implanted into the portal vein of six anesthetized pigs (23.5 +/- 2.9 kg body wt). Three consecutive, simultaneous injections of FM of two different colors into the chamber were performed. Reference portal blood samples were collected by means of a Harvard pump. At the end of the experiment, the liver was explanted and fixed in formalin before dissection. FM were isolated from the tissue samples by an automated process, and fluorescence intensity was determined. Comparison of 5,458 single RPBF values, determined by simultaneously injected FM, revealed good agreement (bias 2.5%, precision 12.7%) and high correlation (r = 0.97, r2 = 0,95, slope = 1.04, intercept = 0.05). Median RPBF was 1.07 +/- 0.78 ml x min(-1) x g(-1). Allocation of the blood flow values to the anatomic regions of the liver revealed a significantly higher RPBF (P = 0.01) in the liver tissue located close to the diaphragm compared with the rest of the organ and a significantly lower RPBF (P = 0.01) in the left liver lobe compared with the median and right lobes. The results show that the model presented makes it possible to measure RPBF by means of FM reliably and that RPBF is distributed heterogeneously in the porcine liver.

A continuous quality improvement approach to IL-372 documentation compliance in an academic emergency department, and its impact on dictation costs, billing practices, and average patient length of stay.

OBJECTIVE: To determine whether continuous quality improvement (CQI) methodology could improve and maintain IL-372 documentation compliance in an academic emergency department (ED). The impact on transcription costs, billing practices, and average patient length of stay was also analyzed. METHODS: Baseline IL-372 compliance data were collected and shared with staff during a multidisciplinary educational session. Faculty dictation became mandatory. Pocket-sized dictation templates were provided. A Documentation Improvement Committee monitored outcomes. Each month of the study period, a compliance officer reviewed approximately 100 records. The following indicators were monitored: IL-372 compliance rates, dictation rates, transcription costs, down-coding rates, percentage of billable records, and average patient length of stay. Individualized results were provided to faculty. RESULTS: During the ten-month study period, compliance rates increased from 60% to 100% (p-trend < 0.001), while dictation rates increased from 69% to 100% (p < 0.001). Rates of down-coding adjustments improved from 54% to 2% (p-trend < 0.001). The percentage of billable records increased from 65% to 100% (p-trend < 0.001). Transcription costs increased a modest 16%. The average patient length of stay remained unchanged. CONCLUSION: The application of CQI methodology, combined with the availability of dictation, resulted in sustained improvement in IL-372 compliance. This was associated with a parallel increase in dictation rates, although concurrent transcription costs increased only modestly. The percentage of billable records increased, while the number of charts requiring down-coding decreased, both beneficial outcomes. Average length of stay was not adversely impacted by this added documentation requirement.

Program description: a hospitalist-run, medical short-stay unit in a teaching hospital.

A hospitalist-run medical short-stay unit (MSSU) was created at a university-affiliated teaching hospital in Montreal in 1989. Its primary aim was to provide efficient and high-quality care to patients requiring a brief stay in hospital for short-lived medical conditions. After evaluation in the emergency department (ED), patients judged to have acute conditions requiring a short hospital stay are admitted directly to the MSSU. Conversely, patients with more complex conditions requiring a longer stay in hospital are admitted to a clinical teaching unit (CTU). Care in the MSSU is provided by a rotating group of hospitalists. Ensuring the admission of appropriate patients during non-daytime hours was the main difficulty identified. Preliminary evaluation of the MSSU suggested that ED consultants were effective at selecting suitable patients for admission to the MSSU, because only 1 in 5 patients later required transfer to other hospital wards. The 5 most common MSSU discharge diagnoses were asthma and chronic obstructive lung disease, pneumonia, congestive heart failure, urinary tract infection and cellulitis. MSSU patients had a shorter length of stay, lower rates of in-hospital complications and lower rates of readmission within 30 days of discharge compared with CTU patients. Our hospitalist-run MSSU appears to offer a workable system of health care delivery for patients with acute, self-limited illness requiring a brief stay in hospital. The MSSU appeared to promote the efficient use of hospital beds without compromising patient outcomes, however, further research is required to compare the efficiency and outcomes of care directly with that provided by the traditional CTU system.

Viability of cultured nerve grafts: An assessment of proliferation of Schwann cells and fibroblasts.

Previous studies demonstrated that the viability of nerve grafts had a positive effect on nerve regeneration, while the cold storage of nerve grafts obtained few viable cells at the later stage. The purpose of this study was to examine the cellular activities of Schwann cells and fibroblasts in cultured nerve grafts prior to transplantation. 2.5-cm long sciatic nerve grafts were harvested from 75 male Lewis rats. Two different media were utilized to culture the nerve grafts up to 3 weeks: Dulbecco's modified eagle medium (DMEM) only or DMEM supplemented with 2 microM forskolin and 10 microg/ml pituitary exact (mitogen medium for Schwann cells). In vivo predegenerated and normal nerve grafts were used as positive and negative controls, respectively. We employed a 5-bromo-2'-deoxyuridine (BrdU) incorporation method to evaluate the proliferating cells in the cultured nerve grafts. S-100 and vimentin immunostaining were used to estimate the presence of Schwann cells and fibroblasts in all nerve grafts at different intervals. The results showed that the proliferating cells increased progressively under culture conditions. The proliferating cells distributed evenly in small fascicles (average diameter 251 +/- 71.5 microm), whereas they appeared mainly in the margin of large fascicles (average diameter 624 +/- 87.3 microm). The mitogen medium stimulated Schwann cell multiplication more significantly in comparison with DMEM after 3 days of culture (P < 0.01), however, there were fewer fibroblasts present in the mitogen medium than in DMEM after 2 days of culture (P < 0.01). It is suggested that the viability of nerve grafts can be preserved under culture conditions. Furthermore, the cellular activity of the Schwann cells and fibroblasts in nerve grafts can be manipulated in in vitro Wallerian degeneration.

Diabetes and pregnancy. Preconception care, pregnancy outcomes, resource utilization and costs.

OBJECTIVE: To describe and compare pregnancy outcomes, resource utilization and costs among women with diabetes who receive and do not receive preconception care. STUDY DESIGN: A multicenter, prospective, observational study of women with type 1 diabetes who received preconception care (PC), became pregnant and delivered (PC women) and women with type 1 diabetes who received prenatal care (PC) only and delivered (PN women). RESULTS: As compared to PN women (n = 74), PC women (n = 24) were seen earlier in gestation and had significantly lower glycosylated hemoglobin levels. The combined number of outpatient visits for PC women was not greater than for PN women. PC women were hospitalized significantly less during pregnancy and tended to have shorter inpatient stays. The mean length of stay after delivery was significantly shorter for PC women. Intensity of care tended to be lower and length of stay shorter for infants of mothers who received PC care. The net cost saving associated with PC care was approximately $34,000 per patient. CONCLUSION: PC achieves its major intended health benefits and is associated with reduced resource utilization and substantially reduced costs. For both health and economic reasons, clinical practice and public policy should embrace PC.

Increased efficiency of analyses: cumulative logistic regression vs ordinary logistic regression.

The common practice of collapsing inherently continuous or ordinal variables into two categories causes information loss that may potentially weaken power to detect effects of explanatory variables and result in Type II errors in statistical inference. The purpose of this investigation was to illustrate, using a substantive example, the potential increase in power gained from an ordinal instead of a dichotomous specification for an inherently continuous response. Ordinary (OLR) and cumulative logistic regression (CLR) modeling were used to test the hypothesis that the risk of alveolar bone loss over 2 years is greater for subjects with poorer control of non-insulin-dependent diabetes mellitus (NIDDM) than for those who do not have diabetes or have better controlled NIDDM. There were 359 subjects; 21 of whom had NIDDM. Analysis of main effects using OLR for the dichotomous outcome (no change in radiographic bone loss vs any change) produced parameter estimates for better control and poorer control that were not statistically significant. CLR analysis of main effects using a 4-category ordinal specification for radiographic bone loss also produced a parameter estimate for better control that was not statistically significant, but which estimated poorer control to have a significant effect. The fit of this CLR model was significantly better at P < 0.05 than that for the OLR. While an OLR model testing the interaction between age and control status did not converge after 100 iterations, the CLR interaction model converged without difficulty and estimated a significant effect for interaction between age and poorer control. Results from the CLR analysis, in contrast to the OLR model, would lead one to conclude that the risk for more severe bone loss progression after 2 years is greater in subjects with poorer controlled NIDDM and that subjects with better controlled NIDDM may not have greater risk of bone loss progression than those without diabetes. The use of an ordinal instead of a dichotomous specification for an inherently continuous response provided increased power, more precise parameter estimates, and a significantly better fitting model. In estimating parameter estimates for odds ratios or risks, it is important to consider using ordinal logistic regression where the response is inherently continuous or ordinal.