Changes in testicular size, echotexture, and arterial blood flow associated with the attainment of puberty in Dorper rams raised in a subtropical climate.

There is a paucity of information on the relationships of testicular morphology, echotextural attributes, and blood flow dynamics with pubertal development of rams raised in a subtropical climate. Forty-five Dorper rams (24 rams aged 8-11 months and 21 rams aged 12-24 months) were examined using a portable ultrasound scanner connected to a 7.5-MHz transducer. Computer-assisted analyses of testicular ultrasonograms utilized commercially available Image ProPlus® analytical software. Spectral Doppler scans of testicular arteries were performed immediately after scrotal (B-mode) ultrasonography to determine peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI = [PSV-EDV]/PSV), and pulsatility index (PI = [SPV-EDV]/mean velocity) of the blood vessels. The length of the testes (9.7 ± 0.3 compared with 9.0 ± 0.2 cm) and scrotal circumference (33.3 ± 0.5 compared with 31.8 ± 0.4 cm) were greater (p < 0.05) but testicular depth (4.5 ± 0.1  compared with 4.9 ± 0.08 cm) was less (p < 0.05) in sexually mature compared with peripubertal rams. [Corrections added on 9 Jan 2019 after initial online publication: The testicular size values in the sentence were corrected.] There were no differences (p > 0.05) between the two age groups of Dorper rams in blood flow indices of testicular arteries. Mean numerical pixel values (100.5 ± 4.1 compared with 89.2 ± 4.8) and pixel heterogeneity (25.6 ± 0.6 compared with 23.6 ± 0.5) of testicular parenchyma were greater (p < 0.05) in peripubertal than in postpubertal rams. Semen volume was negatively correlated with PI of testicular arteries (r = -0.57, p = 0.04). In summary, the attainment of sexual maturity in the rams of the present study was associated with significant changes in testicular length and depth, scrotal circumference, and parenchymal echogenicity/hetrogeneity but not in testicular volume and blood perfusion rates. Testicular artery PI can be used to predict the volume of ejaculate in rams.

Acoustic radiation force impulse (ARFI) elastography to asses maternal and foetal structures in pregnant ewes.

The aim of this study was to evaluate the stiffness of foetal lungs, liver, kidneys and placentomes by acoustic radiation force impulse (ARFI) elastography in ovine and to correlate obtained findings with foetal development. Twenty-four ewes were included, and tissue stiffness of foetal lung, liver, kidney and placentome was measured beginning with 10th gestational week by qualitative-quantitative ARFI elastography. A total of 33 healthy lambs were born. Qualitative elastographic analysis permitted to classify maternal and foetal tissues elasticity in decreasing order as follows: placentome, kidney, liver and lung. Regarding quantitative ARFI elastography data, shear wave velocity (SWV) of foetal lung and liver varied. The lung SWV decreased gradually from the 16th to the 21st gestational week (R2  = 0.80; p < 0.001), while liver SWV increased gradually from the 14th to 21st gestational week (R2  = 0.80; p < 0.001). In contrast, the kidneys and placentomes SWV's remained constant through gestation (p = 0.076; and 0.34). ARFI elastography was shown feasible for evaluation of maternal and foetal tissues stiffness in the ovine model. It can be used to demonstrate pulmonary and hepatic stiffness modifications during foetal development.

Rate of EGFR mutation testing for patients with nonsquamous non-small-cell lung cancer with implementation of reflex testing by pathologists.

BACKGROUND: Testing for mutation of the EGFR (epidermal growth factor receptor) gene is a standard of care for patients with advanced nonsquamous non-small-cell lung cancer (nsclc). To improve timely access to EGFR results, a few centres implemented reflex testing, defined as a request for EGFR testing by the pathologist at the time of a nonsquamous nsclc diagnosis. We evaluated the impact of reflex testing on EGFR testing rates. METHODS: A retrospective observational review of the Web-based AstraZeneca Canada EGFR Database from 1 April 2010 to 31 March 2014 found centres within Ontario that had requested EGFR testing through the database and that had implemented reflex testing (with at least 2 years' worth of data, including the pre- and post-implementation period). RESULTS: The 7 included centres had requested EGFR tests for 2214 patients. The proportion of pathologists requesting EGFR tests increased after implementation of reflex testing (53% vs. 4%); conversely, the proportion of medical oncologists requesting tests decreased (46% vs. 95%, p < 0.001). After implementation of reflex testing, the mean number of patients having EGFR testing per centre per month increased significantly [12.6 vs. 4.9 (range: 4.5-14.9), p < 0.001]. Before reflex testing, EGFR testing rates showed a significant monthly increase over time (1.37 more tests per month; 95% confidence interval: 1.19 to 1.55 tests; p < 0.001). That trend could not account for the observed increase with reflex testing, because an immediate increase in EGFR test requests was observed with the introduction of reflex testing (p = 0.003), and the overall trend was sustained throughout the post-reflex testing period (p < 0.001). CONCLUSIONS: Reflex EGFR testing for patients with nonsquamous nsclc was successfully implemented at multiple centres and was associated with an increase in EGFR testing.

Chemical composition and evaluation of acute toxicological, antimicrobial and modulatory resistance of the extract of Murraya paniculata.

CONTEXT: Murraya paniculata (Linn) JACK (Rutaceae) is used in traditional medicine in the treatment of diabetes, inflammation, and microbial disorders. OBJECTIVE: This study determined the polyphenol composition and antimicrobial and acute toxicological activity of the hydroethanolic extract of M. paniculata leaves (EEMp). MATERIALS AND METHODS: Chemical composition was evaluated by the Folin-Ciocalteu and AlCl3 assays and by HPLC-DAD. Antibacterial and modulatory activity was determined by the microdilution method. Toxicity was assessed with a single dose of EEMp administered orally at doses of 2000 and 5000 mg/kg body weight/day in male and female Swiss mice. RESULTS: Total phenolic content of the EEMp samples varied from 66.5 to 396.8 mg gallic acid equivalent/g of extract and flavonoid content varied from 0.3 to 31.1 mg quercetin equivalent/g of extract. The principal component identified by HPLC-DAD assay was ellagic acid. The results of oral acute toxicity showed no mortality, changes in hematological parameters, or CNS and ANS toxicities in rats. Biochemical analysis showed a significant increase in glucose and glutamic oxaloacetic transaminase activity and reduction in triglycerides and cholesterol for 5000 and 2000 mg/kg doses, respectively, when compared with the control group. Histopathological evaluation showed no significant microscopic changes. EEMp showed essentially no antimicrobial activity, but when aminoglycosides were combined with EEMp their MIC was reduced. CONCLUSIONS: Significant effects were observed in the acute toxicity assay, but they had no clinical relevance. The results suggest that M. paniculata could be used as a source of natural products with antibacterial resistance-modifying activity, with lower toxicity.

Outcomes following surgery for perforating Crohn's disease.

BACKGROUND: The most common indications for surgery for patients with ileocolic Crohn's disease are fibrostenotic or perforating disease. The objective was to compare surgical outcomes of patients with perforating versus non-perforating disease following ileocolic resection. METHODS: This was a retrospective review of all patients who had their first ileocolic resection between 1990 and 2010, identified from a prospectively maintained inflammatory bowel disease database. Demographic information, preoperative medication, intraoperative findings and postoperative outcome data were collected. Outcomes in patients who had an abscess drained before surgery or were found to have a fistula or abscess at surgery or at pathology were compared with outcomes in all others. RESULTS: A total of 434 patients (56·2 per cent women) were included, 293 with perforating and 141 with non-perforating disease. Median age, tobacco use, and preoperative steroid and biological agent use were similar in the two groups. Forty patients (13·7 per cent) in the perforating group had abscesses drained before surgery and 251 patients had at least one fistula, most commonly to the sigmoid colon. Patients with perforating disease were more likely to require preoperative total parenteral nutrition, need another resection, have an ileostomy and a longer mean postoperative stay, and less likely to undergo a laparoscopic procedure. Patients in this group also developed more postoperative abscesses or leaks (4·8 versus 0 per cent; P = 0·006). The reoperation rate was similar (3·1 versus 0·7 per cent; P = 0·178). CONCLUSION: Patients with penetrating Crohn's disease are more likely to require a more complex procedure, and an ileostomy, and to a have longer postoperative stay.

Long-term outcome of colectomy and ileorectal anastomosis for Crohn's colitis.

BACKGROUND: Ileorectal anastomosis is an important surgical option for patients with Crohn's colitis with relative rectal sparing. OBJECTIVE: This study aimed to audit outcomes of ileorectal anastomosis for Crohn's and factors associated with proctectomy and reoperation. DESIGN: This retrospective study involved a chart review and contacting patients. SETTINGS: Patients with Crohn's colitis who had an ileorectal anastomosis were identified from the Mount Sinai Hospital Inflammatory Bowel Disease Database. PATIENTS: Demographics, operative and perioperative outcomes, and reoperative data were collected. MAIN OUTCOME MEASURES: Five- and 10-year Kaplan-Meier survival estimates and 95% confidence intervals were calculated for survival from proctectomy and Crohn's-related revisional surgery. Cox proportional hazards models were used to model the hazards of proctectomy and Crohn's-related revision on the clinical characteristics of patients. RESULTS: Eighty-one patients had an ileorectal anastomosis for Crohn's disease from 1982 to 2010. The most common indications for surgery were failed medical management (60/81, 74.1%) and a stricture causing obstruction (14/81, 17.3%). Seventy-seven percent (n = 62) had a 1-stage procedure, whereas 23% (n = 19) had a 2-stage procedure (colectomy followed by ileorectal anastomosis). The overall anastomotic leak rate was 7.4% (n = 6). Fifty-six patients had a functioning ileorectal anastomosis at the time of follow-up. At 5 and 10 years, 87% (95% CI: 75.5-93.3) and 72.2% (95% CI: 55.8-83.4) of individuals had a functioning ileorectal anastomosis. Eighteen patients required proctectomy for poor symptom control, whereas 11 patients required a small-bowel resection plus redo-ileorectal anastomosis. The mean time to proctectomy from the original ileorectal anastomosis was 88.3 months (SD = 62.1). Smoking was associated with both proctectomy (HR 3.93 (95% CI: 1.46-10.55)) and reoperative surgery (HR 2.12 (95% CI: 0.96-4.72)). LIMITATIONS: : This study was retrospective. CONCLUSIONS: Ileorectal anastomosis is an appropriate operation for selected patients with Crohn's colitis with sparing of the rectum. However, patients must be counseled that the reoperation rate and/or proctectomy rate is approximately 30%.

Predictive validity and measurement issues in documenting quit intentions in population surveillance studies.

INTRODUCTION: Discrete classification of smokers by intention to quit is desirable in many public health and clinical settings. METHODS: Two methodological studies examine measurement properties of measures of discrete-time intention to quit smoking used in population-based tobacco surveillance surveys: an ecological comparison of rates of positive intention in relation to the form of measure used and a prospective analysis examining predictive validity of self-reported quit intentions using multiple possible points of dichotomization of an ordinal measure of intention to quit. The prospective analysis used a repeated measures design and follow-up to 1 year for 2,047 smokers in the Ontario Tobacco Survey cohort. RESULTS: The estimated percent of smokers intending to quit was significantly higher using the Stages of Change intention measure, relative to another single question measure. Significant dose-response effects were found. The sooner one intended to quit the more likely one was to make an attempt or achieve at least 30 days abstinence in the next 6 months. Intending to quit in a month or later was not associated with cessation during follow-up among respondents without prior attempts. Examination of cutpoints revealed no value, which maximized both positive and negative prediction. Regardless of quit attempt history, greatest predictive validity was found where respondents stated that they had no intention at all. DISCUSSION: Measures of intentions quit smoking in specific time periods and expressed as dichotomies have limited psychometric properties but utility in applied research. Our findings suggest a possible measurement effect warranting caution in comparisons across studies.

Local α1-adrenergic blockers: An alternative for sheep cervix dilation?

To facilitate transcervical artificial insemination in sheep, the effects of local treatment with α1-adrenergic receptor antagonists on cervix dilation and hemodynamics were evaluated. Ewes (n = 7) were subjected to oestrous synchronisation every 40 days and assigned to treatments in a Latin square experimental design (seven animals × seven periods) with a factorial treatment arrangement (A × B), Factors A (prazosin or tamsulosin) and B (1, 2, or 4 mg/animal). Ewes of the six treatment groups (P1, P2, P4, T1, T2, and T4) were administered α1-adrenergic receptor antagonists while those of the control group (CG) were administered only α1-adrenergic antagonist carrier agent. Distance that the transcervical catheter penetrated without cervical resistance, mean arterial pressure, and uterine artery dopplerfluxometry were evaluated before and after 30 min, 1, 2, 4, 8, and 10 h of treatment. Catheter penetration distance was greater in ewes of the T4 and P4 groups (P < 0.01), with there being a positive correlation between dose and distance (r = 0.243). The penetration distance was similar (P = 0.84) for treated groups, with the greatest penetration occurring 2, 4, and 6 h after treatment (P < 0.01). The passage into the uterine lumen was greater (P = 0.013) in ewes of the P4 (17.9 %) and T4 (19.6 %) groups. There were no effects on blood pressure or uterine blood flow (P> 0.05). These preliminary results indicate there are benefits of treatment with 4 mg/animal of tamsulosin or prazosin in catheter passage through the sheep cervix 2-6 h after administration without hemodynamic effects.

Colorectal cancer surgery in elderly patients: presentation, treatment, and outcomes.

PURPOSE: This study was designed to characterize the presentation, care, and outcomes of persons older than 75 years, compared with persons 50 to 74 years of age, selected for colorectal cancer. METHODS: Patients over the age of 50 years who had surgery for colon or rectal cancer at the Mount Sinai Hospital between 1997 and 2006 were identified. Data were obtained from a colorectal cancer database and from office and hospital records. Patients were assigned to two groups: 50 to 74 years old and 75 years and older. RESULTS: There were 623 patients in the younger group (mean age, 62.6 years) and 275 in the older group (mean age, 81.5 years). The in-hospital mortality rate was 1% in the younger group compared with 4.2% in the older (P = 0.002). The overall five-year survival was 68.7% and 57.3% in the younger and older groups, respectively, whereas colorectal cancer-specific five-year survival was not significantly different (74.0% vs. 74.7%). There were significant differences between the two groups with respect to cancer location, American Society of Anesthesiologists' score, stage, proportion detected by screening, length of stay, and use of chemotherapy. CONCLUSIONS: Long-term colorectal cancer-related outcomes in the older group are similar to the outcomes in younger patients, suggesting that the decision to operate should not be based on age alone.

Origin and use of the 100 cigarette criterion in tobacco surveys.

Truly global standards and definitions will likely never exist for tobacco control surveillance. One difference across definitions of smoking status is whether or not a lifetime consumption of 100 cigarettes is a necessary criterion for ever and current smoking. Frequently asked questions about this measure demonstrate a need for information on its development and appropriateness in different settings. This commentary attempts to assemble information on the origin and adoption of this measure and provide some critical commentary on its usefulness. The question has been traced to Canadian and American mortality cohort studies from the mid-1950s. From there it has spread to inconsistent use in many settings. To our knowledge, it was not originally (or since) empirically defined as a threshold of exposure related to health consequences or future smoking risk when used in youth. Anecdotal evidence over several decades, however, shows the question has pragmatic utility in self-report data collection. It is a useful, if somewhat arbitrary, screener for "never regular" tobacco use among adults, where never smoking needs to be defined in data collection. Use of the criterion may lower prevalence estimates somewhat. Definitions must always be considered when creating time-trends or international comparisons. There are also circumstances where it is inappropriate to exclude individuals who do not meet this criterion from further data collection, or reports. For research in youth, the criterion typically should be used only with more detailed information about experimentation, but it may be a useful additional indicator of established smoking.

Experiences with rotavirus vaccines: can we improve rotavirus vaccine impact in developing countries?

Rotavirus vaccines have been introduced into over 95 countries globally and demonstrate substantial impact in reducing diarrheal mortality and diarrheal hospitalizations in young children. The vaccines are also considered by WHO as "very cost effective" interventions for young children, particularly in countries with high diarrheal disease burden. Yet the full potential impact of rotavirus immunization is yet to be realized. Large countries with big birth cohorts and where disease burden is high in Africa and Asia have not yet implemented rotavirus vaccines at all or at scale. Significant advances have been made demonstrating the impact of the vaccines in low- and lower-middle income countries, yet the modest effectiveness of the vaccines in these settings is challenging. Current research highlights these challenges and considers alternative strategies to overcome them, including alternative immunization schedules and host factors that may inform us of new opportunities.

Influence of estrous cycle and gestation on cardiovascular system of bitches.

The purpose of this study was to evaluate the consequences of the estrous cycle and gestation on the cardiovascular system of bitches evaluated through echocardiographic assessment. Fifteen healthy pregnant bitches aged 2 to 6 years and weighing 8.8 ±â€¯2.5 kg were included in the study. Heart rate and blood pressure were clinically evaluated. M-mode, spectral, and tissue Doppler-echocardiography assessments were performed during the anestrous and estrous stages, every 15 days during pregnancy (15, 30, 45, and 60 days), and 45 days postpartum. The data for evaluated variables were submitted for statistical analysis. Heart rate (P = 0.286) and systolic blood pressure (P = 0.686) were not changed as a result of pregnancy or estrus, while ejection fraction (P = 0.0016) and fractional shortening (P = 0.00004) changed. The variables transmitral flow, isovolumetric relaxation time, aortic and pulmonary flow, and some variables related to myocardium movement obtained via tissue Doppler assessment varied (P < 0.05) among the reproductive periods studied. In conclusion, gestation resulted in changes in echocardiography variables, and consequently, on maternal hemodynamics, with myocardial contractility increasing during pregnancy, resulting in greater systolic efficiency and ventricular compliance.

Visible and UVA light as a potential means of preventing Escherichia coli biofilm formation in urine and on materials used in urethral catheters.

Catheter-associated urinary tract infections are the most common hospital-acquired infection, for which Escherichia coli is the leading cause. This study investigated the efficacy of 385nm and 420nm light for inactivation of E. coli attached to the silicone matrix of a urinary catheter. Using urine mucin media, inactivation of planktonic bacteria and biofilm formation was monitored using silicone coupons. Continuous irradiance with both 385nm and 420nm wavelengths with starting cell density population 103CFU ml-1 reduced planktonic suspensions of E. coli to below the detection level after 2h and 6h, respectively. Bacterial attachment to silicone was successfully prevented during the same treatment. Inactivation by 385nm and 420nm was found to be dependent on media, cell density and oxygen, with less inhibition on planktonic suspensions when higher starting cell densities were used. In contrast to planktonic suspensions in PBS, continuous irradiance of pre-established biofilms showed a greater reduction in survival compared to urine mucin media after 24h. Enhanced inhibition for 385nm and 420nm light in urine mucin media was associated with increased production of reactive oxygen species. These findings suggest 385nm and 420nm light as a promising antimicrobial technology for the prevention of biofilm formation on urethral catheters.

Relationship between neurocognitive functioning and medication management ability over the first 6 months following allogeneic stem cell transplantation.

Although neurocognitive impairment has been established as a major issue among cancer survivors, the real-world consequences of this impairment are unclear. This study investigated the relationship between neurocognitive functioning and medication management ability over time among 58 patients treated with allogeneic hematopoietic stem cell transplantation (HCT). Participants completed a neuropsychological test battery and a simulated medication management task at three time points: pre-transplant (T0), Day 100 (T1) and 6 months post transplant (T2). Neurocognitively impaired participants performed worse on the medication management task than neurocognitively normal participants at each time point, and were more likely to score in the impaired range of medication management ability post transplant (72% vs 20%, P<0.001 at T1; 67% vs 23%, P=0.013 at T2). In multivariate analyses, worse performance in executive functioning/working memory consistently predicted impaired medication management ability, even when controlling for sociodemographic and clinical confounders (odds ratio=0.89, 95% confidence interval (0.80, 0.98), P=0.023). Lower physical symptom distress also predicted impaired medication management ability, but this effect decreased over time. Self-reported cognitive problems were not correlated with medication management ability at any time point. Findings suggest that poor neurocognitive functioning, particularly in the domain of executive functioning/working memory, is associated with worse medication management ability within the first 6 months after allogeneic HCT.

Gestational echobiometry in brachycephalic bitches using high-definition ultrasonography

ABSTRACT: The objective of the present study was to obtain echobiometric values for the most important canine maternal-fetal tissues using high-definition ultrasonography (HDUS) trying to update the formulas for predicting gestational age. Twelve healthy bitches of brachycephalic breeds weighing 7-13kg and aged one to four years were included. The fetuses were analyzed every day using conventional and high-definition ultrasonography from the eighth day after artificial insemination until the day of delivery, using the ACUSON S2000/SIEMENS ultrasound equipment and specific software. Embryonic and fetal structures; diameter of the embryonic vesicle; length of the embryo; biparietal diameter, abdominal length and kidney height; length of the femur, humerus, scapula, radius, and tibia; thickening of the stomach wall; adrenal length; and cardiac size were measured. These variables were correlated with gestational and adjusted tested according to regression models. The results obtained (P 0.001) for: lateral diameter of the gestational sac (R2=81.8%); length of the embryo (R2=85.7%); biparietal (R2=99.1%) and abdominal diameter (R2=97.2%); thickness of the gastric wall (R2=86.9%); length of the femur (R2=96.6%), radius (R2=97.5%), humerus (R2=96.5%), scapula (R2=95.8%) and tibia (R2=97.3%); kidney length (R2=95.8%) and height (R2=96.0%); adrenal length (R2=89.6%); heart length (R2=93.0%) and height (R2=91.5%) of the canine fetuses showed significant correlation with gestational days. This allowed monitoring fetal growth and estimation of age with high accuracy in different gestational periods.

RESUMO: O objetivo do presente estudo foi obter valores ecobiométricos para os tecidos materno-fetais caninos, usando a ultrassonografia de alta definição (HDUS), desenvolvendo fórmulas para prever a idade gestacional das cadelas. Doze cadelas saudáveis de raças braquicefálicas pesando 7-13kg e com idades entre um e quatro anos foram incluídas. Os fetos foram analisados diariamente com ultrassonografia convencional e de alta definição, do oitavo dia após a inseminação artificial até o dia do parto, utilizando o equipamento de ultrassom ACUSON S2000/SIEMENS e software específico. Estruturas embrionárias e fetais; diâmetro da vesícula embrionária; comprimento do embrião; diâmetro biparietal, comprimento abdominal e altura renal; comprimento do fêmur, úmero, escápula, rádio e tíbia; espessamento da parede do estômago; comprimento adrenal; e tamanho cardíaco foram medidos. Essas variáveis foram correlacionadas com o teste gestacional e ajustado de acordo com os modelos de regressão. Os resultados obtidos (P 0,001) para: diâmetro lateral do saco gestacional (R2=81,8%); comprimento do embrião (R2=85,7%); diâmetro biparietal (R2=99,1%) e abdominal (R2=97,2%); espessura da parede gástrica (R2=86,9%); comprimento do fêmur (R2=96,6%), rádio (R2=97,5%), úmero (R2=96,5%), escápula (R2=95,8%) e tíbia (R2=97,3%); comprimento do rim (R2=95,8%) e altura (R2=96,0%); comprimento adrenal (R2=89,6%); o comprimento do coração (R2=93,0%) e a altura (R2=91,5%) dos fetos caninos apresentaram correlação significativa com os dias gestacionais. Isso permitiu monitorar o crescimento fetal e estimar a idade com alta precisão em diferentes períodos gestacionais.

Gestational echobiometry in brachycephalic bitches using high-definition ultrasonography / Ecobiometria gestacional em cadelas braquicefálicas utilizando ultrassonografia de alta-definição

The objective of the present study was to obtain echobiometric values for the most important canine maternal-fetal tissues using high-definition ultrasonography (HDUS) trying to update the formulas for predicting gestational age. Twelve healthy bitches of brachycephalic breeds weighing 7-13kg and aged one to four years were included. The fetuses were analyzed every day using conventional and high-definition ultrasonography from the eighth day after artificial insemination until the day of delivery, using the ACUSON S2000/SIEMENS ultrasound equipment and specific software. Embryonic and fetal structures; diameter of the embryonic vesicle; length of the embryo; biparietal diameter, abdominal length and kidney height; length of the femur, humerus, scapula, radius, and tibia; thickening of the stomach wall; adrenal length; and cardiac size were measured. These variables were correlated with gestational and adjusted tested according to regression models. The results obtained (P<0.001) for: lateral diameter of the gestational sac (R2=81.8%); length of the embryo (R2=85.7%); biparietal (R2=99.1%) and abdominal diameter (R2=97.2%); thickness of the gastric wall (R2=86.9%); length of the femur (R2=96.6%), radius (R2=97.5%), humerus (R2=96.5%), scapula (R2=95.8%) and tibia (R2=97.3%); kidney length (R2=95.8%) and height (R2=96.0%); adrenal length (R2=89.6%); heart length (R2=93.0%) and height (R2=91.5%) of the canine fetuses showed significant correlation with gestational days. This allowed monitoring fetal growth and estimation of age with high accuracy in different gestational periods.(AU)

O objetivo do presente estudo foi obter valores ecobiométricos para os tecidos materno-fetais caninos, usando a ultrassonografia de alta definição (HDUS), desenvolvendo fórmulas para prever a idade gestacional das cadelas. Doze cadelas saudáveis de raças braquicefálicas pesando 7-13kg e com idades entre um e quatro anos foram incluídas. Os fetos foram analisados diariamente com ultrassonografia convencional e de alta definição, do oitavo dia após a inseminação artificial até o dia do parto, utilizando o equipamento de ultrassom ACUSON S2000/SIEMENS e software específico. Estruturas embrionárias e fetais; diâmetro da vesícula embrionária; comprimento do embrião; diâmetro biparietal, comprimento abdominal e altura renal; comprimento do fêmur, úmero, escápula, rádio e tíbia; espessamento da parede do estômago; comprimento adrenal; e tamanho cardíaco foram medidos. Essas variáveis foram correlacionadas com o teste gestacional e ajustado de acordo com os modelos de regressão. Os resultados obtidos (P<0,001) para: diâmetro lateral do saco gestacional (R2=81,8%); comprimento do embrião (R2=85,7%); diâmetro biparietal (R2=99,1%) e abdominal (R2=97,2%); espessura da parede gástrica (R2=86,9%); comprimento do fêmur (R2=96,6%), rádio (R2=97,5%), úmero (R2=96,5%), escápula (R2=95,8%) e tíbia (R2=97,3%); comprimento do rim (R2=95,8%) e altura (R2=96,0%); comprimento adrenal (R2=89,6%); o comprimento do coração (R2=93,0%) e a altura (R2=91,5%) dos fetos caninos apresentaram correlação significativa com os dias gestacionais. Isso permitiu monitorar o crescimento fetal e estimar a idade com alta precisão em diferentes períodos gestacionais.(AU)

Comparison of the ability of freeze etch and freeze substitution to preserve actin filament structure.

In order to test the ability of freeze substitution to accurately preserve the ultrastructure of the actin component of the cytoskeleton, the structure of rotary shadowed actin filaments was compared following preparation by glutaraldehyde fixation and freeze etch or freeze substitution. Freeze substituted actin filaments were further processed by either etching away frozen organic solvent or critical-point-drying before rotary shadowing. Comparison of filament diameters showed no significant difference between actin filaments that were directly etched and those that were freeze substituted and then etched. However, freeze substituted and then critical-point-dried filaments were significantly larger in diameter than filaments that were directly etched in water. The long pitch (right-handed) two start helix was not affected by the different methods of preparation. However, the left-handed "genetic" helical repeat that was prominent in actin filaments prepared by freeze etch was more difficult to detect in freeze substituted specimen, especially following critical-point-drying. Although the organization and distribution of actin filaments in extracted cells was similar in both freeze substituted and freeze etched specimens, there were some detectable differences. In cells that were freeze substituted and then critical-point-dried, filaments appeared to intersect at greater angles and seemed more "taut." These results suggest that freeze substitution can preserve the overall morphology of actin filaments, but some chemical or physical modification of macromolecular surface structure may occur during the substitution process and these changes may be further exaggerated by subsequent processing steps.

Immortalized cell lines from embryonic avian and murine otocysts: tools for molecular studies of the developing inner ear.

Recently, our studies have focused on genes expressed at the earliest stages of inner ear development. Our aim is to identify and characterize genes that are involved in determining the axes of the semicircular canals, in otic crest delamination and in early innervation of the inner ear. Many elegant studies of auditory development have been done in animal models. However, the need for large amounts of well-characterized embryonic material for molecular studies makes the development of otocyst cell lines with different genetic repertoires attractive. We have therefore derived immortalized otocyst cells from two of the most widely used animal models of ear development: avians and mice. Avian cell isolates were produced from quail otocysts (embryonic stage 19) that were transformed with temperature-sensitive variants of the Rous sarcoma virus (RSV). Among the individual transformed cells are those that produce neuron-like derivatives in response to treatment with 10(-9) M retinoic acid. Mammalian cell isolates were derived from otocysts, of 9 day (post coitus) embryos of the H2kbtsA58 transgenic mouse (Immortomouse), which carries a temperature-sensitive variant of the Simian Virus 40 Tumor antigen. The vast majority of cells of the Immortomouse are capable of being immortalized at 33 degrees C, the permissive temperature for transgene expression, in the presence of gamma-interferon. Several putative clones et these cells differentiated into neuron-like cells after temperature shift and withdrawal of gamma-interferon; another isolate of cells assumed a neuron-like morphology on exposure to brain-derived neurotrophic factor even at the permissive temperature. We describe also a cell isolate that expresses the Pax-2 protein product and two putative cell lines that express the protein product of the chicken equivalent of the Drosophila segmentation gene engrailed. These genes and their protein products are expressed in specific subpopulation of otocyst cells at early stages. Both mouse and quail immortalized cell lines will be used to study inner ear development at the molecular level.

Reported distribution of Ixodes scapularis and Ixodes pacificus (Acari: Ixodidae) in the United States.

Lyme disease, caused by infection with Borrelia burgdorferi, is the most frequently reported arthropod-borne disease in the United States. To develop a national map of the distribution of the vectors of B. burgdorferi to humans (Ixodes scapularis Say and Ixodes pacificus Cooley & Kohls ticks), we sent questionnaires to acarologists, health officials, and Lyme disease researchers; surveyed the 1966-1996 MEDLINE data base; and reviewed 1907-1995 National Tick Collection data. Tick collection methods cited included flagging and dragging, deer surveys, small- and medium-sized mammal surveys, CO2 baiting, and receipt of tick submissions. A total of 1,058 unique, county-specific I. scapularis and I. pacificus records was obtained. Tick populations were classified as "reported" (< 6 ticks and 1 life stage identified) or "established" (> or = 6 ticks or > 1 life stage identified). Established populations of I. scapularis were identified in 396 counties in 32 states in the eastern and central United States, whereas established populations of I. pacificus were found in 90 counties in 5 western states. Counties with established populations were most concentrated in the northeastern, upper northcentral, and west-coastal states but were also clustered in southeastern and Gulf-coastal states. A less concentrated distribution was found in the south-central states. Reports were notably missing from all but a few counties in Ohio, West Virginia, western Virginia and North Carolina, Kentucky, and Tennessee. They were absent in the Great Plains and Rocky Mountain regions and from large areas of western states east of the Cascade and Sierra Nevada cordilleras. These data are useful for identifying areas of Lyme disease risk, for targeting Lyme disease prevention strategies, and for monitoring trends in spatial distribution of Lyme disease vector ticks.