Mobile Distribution of COVID-19 Vaccines to Migrant Farmworkers in Minnesota

The COVID-19 pandemic has disproportionately impacted migrant farmworkers (MFWs). MFWs have experienced higher rates of infection and death than any other occupational group in the United States due to workplace exposure risks, overcrowded housing, and limited access to personal protective equipment. Barriers to accessing COVID-19 vaccines have also contributed to these disparities, especially in rural areas where the pandemic's impact has been devastating. Mobile health clinics, in partnership with community-based organizations, are an effective method for vaccine distribution to rural communities where many MFWs live and work. Between June 2021 and October 2022, the University of Minnesota's Mobile Health Initiative (MHI) organized health fairs in southern Minnesota to distribute vaccines to MFWs and their families. The success of these events can be attributed to partnering with trusted local organizations, bridging geographic barriers, ensuring language-concordant care, and offering multiple health services in one place. MHI's health fairs serve as a model for future mobile vaccination events. As the COVID-19 pandemic has ended as of this time, future pandemics may occur, and equitable vaccine access must be a priority for MFWs. Mobile health clinics are an essential tool to achieving this goal.

The Impact of a Handheld Ultrasound Device in a Rheumatic Heart Disease Screening Program in Ethiopia

Background: Rheumatic heart disease (RHD) affects 33 million people in low and middle income countries and is the leading cause of cardiovascular death among children and young adults. Penicillin prophylaxis prevents progression in asymptomatic disease. Efforts to expand echocardiographic screening are focusing on simplified protocols, non-physician ultrasonographers, and portable ultrasound devices, including handheld ultrasound. Recent advances support the use of single-view screening protocols. With the increasing availability and low cost of handheld devices, studies are needed to evaluate their performance in these settings. Methods: We conducted a retrospective study comparing the rate of screen positive ultrasounds before and after the use of a handheld ultrasound in an RHD screening program in Ethiopia. We also performed a cross-sectional device comparison in 19 at-risk school-children participating in the rheumatic heart disease screening program. Results: Between March of 2019 and January of 2022, 6631 children were screened for rheumatic heart disease of whom 4029 were screened after the introduction of a handheld device. Before the use of the handheld ultrasound device 291 (11.2%) children had a screen positive ultrasounds compared with 167 (4.1%) afterwards (p<0.001). We also compared non-expert to expert interpretation by device and found a significant difference in interpretation for the Lumify (p=0.025). There was a trend towards shorter jet length by color Doppler in the handheld ultrasound device for both expert and non-expert review. Conclusions: Our study highlights that the screen-positive rate in a RHD screening program is influenced by the device being used in the screening process.

Evaluation of remote radiologist-interpreted point-of-care ultrasound for suspected dengue patients in a primary health care facility in Colombia

BACKGROUND

Early identification of plasma leakage may guide treatment decisions in dengue patients. This study evaluated the value of point-of-care ultrasound (POCUS) to detect plasma leakage and predict hospitalization or referral to a higher level of care in suspected dengue patients under routine conditions at a primary care facility in Colombia.

METHODS

We conducted a cohort study between April 2019 and March 2020 in a primary care hospital in Cali, Colombia. We prospectively included and followed 178 patients who were at least 2 years old with fever of less than 10 days and clinician-suspected dengue. A trained general practitioner performed a standardized POCUS protocol. Images were quality-rated and overread by an expert radiologist, and her results and those of the general practitioner were compared using the Kappa index. Logistic regression was used to identify factors associated with plasma leakage at enrollment and explore its prognostic value regarding hospital admission or referral to a higher level of care.

RESULTS

Half (49.6%) POCUS images were of suitable quality to be interpreted. The proportion of plasma leakage reported by the radiologist was 85.1% (95% CI: 78.6-90.2%) and 47.2% by the study physician (Kappa = 0.25, 95% CI: 0.15-0.35). The most frequent ultrasound findings were ascites (hepatorenal 87.2%, splenorenal 64%, or pelvic 21.8%) and gallbladder wall thickening (10.5%). Plasma leakage was higher in subjects with thrombocytopenia (aOR = 4, 95% CI: 1.3-12.1) and lower in patients 30-59 years old (aOR = 0.1, 95% CI: 0.0-0.4) than in those 18 years old or younger. POCUS evidence of plasma leakage (aOR = 8.2, 95% CI: 2.2-29.9), thrombocytopenia (aOR = 6.3, 95% CI: 2.4-16.0) and pulse pressure (aOR = 1.1, 95% CI: 1.07-1.2) were associated with hospital admission or referral to a higher level of care.

CONCLUSIONS

Ultrasound is useful to detect plasma leakage in primary care and, challenges remain to guarantee high-quality images and diagnostic accuracy, for which a standardized dengue POCUS protocol and training program is needed.

Sabbaticals in US Medical Schools

BACKGROUND

Sabbaticals are an important feature of academia for faculty and their institutions. Whereas sabbaticals are common in institutions of higher learning, little is known about their role and utilization in US medical schools. This perspective piece examining sabbaticals in medical school faculty was undertaken at a time that well-being of health professionals was increasingly being recognized as a workforce health priority.

METHODS

We surveyed associate deans at US medical schools in 2021 about faculty who had taken sabbaticals within the past 3 years, the parameters of the sabbaticals, and institutional policies and respondents' predictions of future sabbatical use.

RESULTS

A total of 53% of respondents reported any faculty had taken sabbaticals in the past 3 years (M = 6.27; Median = 3; range = 1-60). Institutions rated enhancing research as the most important objective, while recognizing other benefits. Sabbaticals were more commonly taken by male, white, senior faculty PhDs. Details about sabbaticals, including eligibility, expectations, length, financial support, and benefits were reviewed. Most (54.8%) respondents expected no change in the number of faculty seeking sabbaticals. Nearly all anticipated the COVID-19 pandemic would not affect sabbatical policies.

CONCLUSION

In contrast to other institutions of higher learning, sabbatical-taking by medical school faculty is rare. We explore factors that may contribute to this phenomenon (eg, the tripartite mission, faculty clinical responsibilities, culture of medicine, and student debt). Despite financial and other barriers, a closer look at the benefits of sabbaticals is warranted as a mechanism that may support faculty well-being, retention, and mental health.

Responding to COVID-19 Through Interhospital Resource Coordination: A Mixed-Methods Evaluation

OBJECTIVES

The COVID-19 pandemic stressed hospital operations, requiring rapid innovations to address rise in demand and specialized COVID-19 services while maintaining access to hospital-based care and facilitating expertise. We aimed to describe a novel hospital system approach to managing the COVID-19 pandemic, including multihospital coordination capability and transfer of COVID-19 patients to a single, dedicated hospital.

METHODS

We included patients who tested positive for SARS-CoV-2 by polymerase chain reaction admitted to a 12-hospital network including a dedicated COVID-19 hospital. Our primary outcome was adherence to local guidelines, including admission risk stratification, anticoagulation, and dexamethasone treatment assessed by differences-in-differences analysis after guideline dissemination. We evaluated outcomes and health care worker satisfaction. Finally, we assessed barriers to safe transfer including transfer across different electronic health record systems.

RESULTS

During the study, the system admitted a total of 1209 patients. Of these, 56.3% underwent transfer, supported by a physician-led System Operations Center. Patients who were transferred were older (P = 0.001) and had similar risk-adjusted mortality rates. Guideline adherence after dissemination was higher among patients who underwent transfer: admission risk stratification (P < 0.001), anticoagulation (P < 0.001), and dexamethasone administration (P = 0.003). Transfer across electronic health record systems was a perceived barrier to safety and reduced quality. Providers positively viewed our transfer approach.

CONCLUSIONS

With standardized communication, interhospital transfers can be a safe and effective method of cohorting COVID-19 patients, are well received by health care providers, and have the potential to improve care quality.

Healthcare Worker Perspectives on COVID-19 Vaccines: Implications for Increasing Vaccine Acceptance among Healthcare Workers and Patients

Objective

To understand COVID-19 vaccine perspectives among healthcare workers serving diverse communities.

Methods

A dual English/Spanish survey was distributed to healthcare workers in the United States from 3/12/2021–4/22/2021 by the Migrant Clinicians Network, Society of Refugee Healthcare Providers, a Federally Qualified Healthcare Center, and social media advertisement to general primary care workers.

Results

517 responses were at least 50% complete and included in the analysis. Among these, 88% (457/517) indicated vaccine acceptance. Factors associated with acceptance included not reporting any vaccine concerns, identifying as male, ≥65 years of age, being a physician or advanced practice provider, and interacting directly with patients from refugee, immigrant, and migrant (RIM) communities. Participants identified educational information as most helpful for themselves when making a vaccine decision, but a healthcare provider’s recommendation as most helpful for their patients.

Conclusion

Healthcare workers, especially those serving RIM communities, are vaccine accepting. Tailoring vaccine-related information to healthcare workers may improve vaccine confidence for both themselves and patients who rely on them for information.

Global Is Local: Interprofessional Experiential Learning for Migrant Farmworker Health Equity

Purpose

Medical educators recognize the importance of addressing social determinants of health and providing opportunities for learners to work with diverse populations. Still, social, geographic, resource, and language barriers prevent institutions from connecting with globally diverse populations within their own communities. In this article, we describe the migrant farmworker health course at the University of Minnesota, the importance of longitudinal partnership with community-based organizations, and ways to increase access to care and educate health professional learners in health equity.

Methods

The migrant farmworker health course is a clinical rotation that combines didactic learning on social determinants of health with hands-on clinical experience. Learners work with community organizations to provide mobile health care while learning about a diverse and underserved rural population. Twenty-eight learners who participated in the course between 2015 and 2019 were surveyed about their experience, knowledge, and skills gained, and recommendations for improvement.

Results

Over 90% of participants rated their overall experience in the course as “good” or “outstanding.” Most learners increased confidence in the subjects that were covered during didactic sessions. Qualitative feedback provided insight on how the migrant farmworker health course shaped learners' understanding of social determinants of health and influenced their career trajectories.

Conclusion

The migrant farmworker health course has educated interprofessional learners and is expanding to include more opportunities for mobile health care. The feedback from this survey helped improve didactic teaching and will help deepen relationships with community partners. Learning through service with global populations locally in a “global is local” rotation is a rewarding way to engage in and learn about health equity.

COVID-19 Awareness and Preparedness of Minnesota and Wisconsin Dairy Farms

Dairy farms that had participated in previous and ongoing projects with the National Farm Medicine Center (NFMC), Migrant Clinicians Network (MCN), and Upper Midwest Agricultural Safety and Health Center (UMASH) were asked to participate in a 17-question survey by phone or email to investigate biosecurity principles on Minnesota and Wisconsin dairy farms in response to COVID-19 and the effects of the pandemic on the dairy industry. Three additional farms were recruited via a press release published in agricultural newsletters. Of 76 farms contacted, 37 chose to participate in this study from June to July 2020. In response to the COVID-19 pandemic, dairies have implemented or increased biosecurity measures and COVID-19 precautions. Dairies reported adequate personal protective equipment for their workers, though face masks were not required on most dairies (n = 32, 86%). Producers were concerned about the safety of their families, maintaining a healthy workforce, and keeping their farms profitable. Access to healthcare was not perceived to be an issue for their workers. One-quarter of dairies reported COVID-19 infections on their farms. Even though the majority had an isolation protocol in place if someone on the farm were to become ill, less than half of respondents felt their farm was protected against COVID-19. Two-thirds of producers have not had to decrease production, and a majority of operations have not furloughed or terminated employees due to COVID-19. Our data suggest that dairy farms in Minnesota and Wisconsin have implemented biosecurity and safety measures in response to COVID-19. These measures can be improved. Farms would benefit from additional guidance and education on implementation of personal protective measures and disease prevention strategies to keep workers employed and safe.

Super fragmented: a nationally representative cross-sectional study exploring the fragmentation of inpatient care among super-utilizers

Background

Super-utilizers with 4 or more admissions per year frequently receive low-quality care and disproportionately contribute to healthcare costs. Inpatient care fragmentation (admission to multiple different hospitals) in this population has not been well described.

Objective

To determine the prevalence of super-utilizers who receive fragmented care across different hospitals and to describe associated risks, costs, and health outcomes.

Research design

We analyzed inpatient data from the Health Care Utilization Project’s State Inpatient and Emergency Department database from 6 states from 2013. After identifying hospital super-utilizers, we stratified by the number of different hospitals visited in a 1-year period. We determined how patient demographics, costs, and outcomes varied by degree of fragmentation. We then examined how fragmentation would influence a hospital’s ability to identify super-utilizers.

Subjects

Adult patients with 4 or more inpatient stays in 1 year.

Measures

Patient demographics, cost, 1-year hospital reported mortality, and probability that a single hospital could correctly identify a patient as a super-utilizer.

Results

Of the 167,515 hospital super-utilizers, 97,404 (58.1%) visited more than 1 hospital in a 1-year period. Fragmentation was more likely among younger, non-white, low-income, under-insured patients, in population-dense areas. Patients with fragmentation were more likely to be admitted for chronic disease management, psychiatric illness, and substance abuse. Inpatient fragmentation was associated with higher yearly costs and lower likelihood of being identified as a super-utilizer.

Conclusions

Inpatient care fragmentation is common among super-utilizers, disproportionately affects vulnerable populations. It is associated with high yearly costs and a decreased probability of correctly identifying super-utilizers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-06323-5.

Ensuring COVID-19 Vaccines for Migrant and Immigrant Farmworkers

Migrant and immigrant farmworkers are cornerstones to food security and production in many nations. In the United States, farmworkers have been disproportionately impacted by COVID-19. Because they are considered essential workers, vaccines may be made imminently available to them and offer an opportunity to reduce these COVID-19–related impacts. It is essential for a successful vaccination campaign to address the unique challenges arising from this workforce’s inherently mobile nature and limited access to healthcare. Proposed strategies to overcome these challenges include ensuring farmworkers are prioritized in vaccine allocation and provided cost-free vaccines at convenient locations through partnerships among health authorities, community- and faith-based groups, and health centers with trusted community relationships. Further, a portable immunization record should be used, and coordination of care continued when a farmworker moves to a new geographic location. If implemented well, vaccinating farmworkers can reduce the COVID-19 disease burden among these essential workers, improve public health, and protect food and agriculture production.

Bovine Tuberculosis: A Re-emerging Zoonotic Infection

Bovine tuberculosis is caused by Mycobacterium bovis (M. bovis), which infects both humans and cattle. In 2018, a dairy farm in Wisconsin was affected by M. bovis, including a farmworker with exposure to the affected herd. Largely eradicated by effective public health strategies in the United States, most cases are now associated with risk factors including occupational hazards, food consumption, and iatrogenic infections. M. bovis continues to cause disease worldwide affecting certain at-risk populations in the United States. Infections more often result in extrapulmonary sequelae and resistance to pyrazinamide is universal. Thus, successful treatment depends on early and correct identification of the mycobacterium species. A One Health approach to control this re-emerging disease is crucial.

A Noninvasive Rhizopus Infection With a Bladder Fungal Ball in a Patient With Poorly Controlled Diabetes Mellitus

Here we present the first reported case of a noninvasive Rhizopus fungal ball confined to the bladder of a patient with poorly controlled diabetes and right flank pain. The patient developed bilateral hydronephrosis after several hospital admissions for urinary tract infections with multiple failed courses of antibiotics. During cystoscopy to replace a ureteral stent, he was found to harbor a fungal ball in the bladder that was removed and grew Rhizopus in culture. Patient received treatment with amphotericin B and transitioned to long-term posaconazole therapy. This case highlights the importance of considering fungal agents in urinary tract infections, especially in persistent or refractory cases, and the role of the clinical microbiology laboratory in correct identification of the infectious source.

The impact of diet and arginine supplementation on pancreatic mass, digestive enzyme activity, and insulin-containing cell cluster morphology during the estrous cycle in sheep

To determine the effect of feed intake and arginine treatment during different stages of the estrous cycle on pancreatic mass, digestive enzyme activity, and histological measurements, ewes (n = 120) were randomly allocated to 1 of 3 dietary groups; control (CON; 2.14-Mcal metabolizable energy/kg), underfed (UF; 0.6 × CON), or overfed (OF; 2 × CON) over 2 yr. Estrus was synchronized using a controlled internal drug release device for 14 d. At controlled internal drug release withdrawal, ewes from each dietary group were assigned to 1 of 2 treatments; Arg (L-Arg HCl, 155-μmol/kg BW) or Sal (approximately 10-mL saline). Treatments were administered 3 times daily via jugular catheter and continued until slaughter on d (day) 5 and 10 of the second estrus cycle (early luteal phase, n = 41 and mid-luteal phase, n = 39; yr 1) and d 15 of the first estrus cycle (late luteal phase, n = 40; yr 2). A blood sample collected from jugular catheters for serum insulin analysis before slaughter. The pancreas was then removed, trimmed of mesentery and fat, weighed, and a sample snap-frozen until enzyme analysis. Additional pancreatic samples were fixed in 10% formalin solution for histological examination of size and distribution of insulin-containing cell clusters. Data were analyzed as a completely randomized design with a factorial arrangement of treatments. Diet, treatment, and diet × treatment were blocked by yr and included in the model with initial BW used as a covariate. Day of the estrous cycle was initially included in the model but later removed as no effects (P > 0.10) were observed for any pancreatic variables tested. Overfed ewes had the greatest (P < 0.001) change in BW, final BW, change in BCS, and final BCS. A diet × treatment interaction was observed for change in BW and final BW (P ≤ 0.004). Overfed and CON had increased (P < 0.001) pancreas weight (g) compared with UF ewes. Protein concentration (g/pancreas) was the lowest (P < 0.001) in UF ewes, whereas protein content (mg/kg BW) was greater (P = 0.03) in UF than OF ewes. Activity of α-amylase (U/g, kU/pancreas, U/kg of BW, and U/g protein) and trypsin (U/pancreas) was greater (P ≤ 0.003) in OF than UF ewes. Serum insulin was the greatest (P < 0.001) in OF ewes. No effects were observed for pancreatic insulin-containing cell clusters. This study demonstrated that plane of nutrition affected several measurements of pancreatic function; however, the dosage of Arg used did not influence pancreatic function.

US of the Inguinal Canal: Comprehensive Review of Pathologic Processes with CT and MR Imaging Correlation

Ultrasonography (US) has a fundamental role in the initial examination of patients who present with symptoms indicating abnormalities of the inguinal canal (IC), an area known for its complex anatomy. A thorough understanding of the embryologic and imaging characteristics of the contents of the IC is essential for any general radiologist. Moreover, an awareness of the various pathologic conditions that can affect IC structures is crucial to preventing misdiagnoses and ensuring optimal patient care. Early detection of IC abnormalities can reduce the risk of morbidity and mortality and facilitate proper treatment. Abnormalities may be related to increased intra-abdominal pressure, which can result in development of direct inguinal hernias and varicoceles, or to congenital anomalies of the processus vaginalis, which can result in development of indirect hernias and hydroceles. US is also helpful in assessing postoperative complications of hernia repair, such as hematoma, seroma, abscess, and hernia recurrence. In addition, it is often the modality initially used to detect neoplasms arising from or invading the IC. US is an important tool in the examination of patients suspected of having undescended testes or posttraumatic testicular retraction and is essential for the examination of patients suspected of having torsion or infectious inflammatory conditions of the spermatic cord. Online supplemental material is available for this article. ^©RSNA, 2016.

Effects of realimentation after nutrient restriction during mid- to late gestation on pancreatic digestive enzymes, serum insulin and glucose levels, and insulin-containing cell cluster morphology

This study examined effects of stage of gestation and nutrient restriction with subsequent realimentation on maternal and foetal bovine pancreatic function. Dietary treatments were assigned on day 30 of pregnancy and included: control (CON; 100% requirements; n = 18) and restricted (R; 60% requirements; n = 30). On day 85, cows were slaughtered (CON, n = 6; R, n = 6), remained on control (CC; n = 12) and restricted (RR; n = 12), or realimented to control (RC; n = 11). On day 140, cows were slaughtered (CC, n = 6; RR, n = 6; RC, n = 5), remained on control (CCC, n = 6; RCC, n = 5) or realimented to control (RRC, n = 6). On day 254, the remaining cows were slaughtered and serum samples were collected from the maternal jugular vein and umbilical cord to determine insulin and glucose concentrations. Pancreases from cows and foetuses were removed, weighed, and subsampled for enzyme and histological analysis. As gestation progressed, maternal pancreatic α-amylase activity decreased and serum insulin concentrations increased (p ≤ 0.03). Foetal pancreatic trypsin activity increased (p < 0.001) with advancing gestation. Foetal pancreases subjected to realimentation (CCC vs. RCC and RRC) had increased protein and α-amylase activity at day 254 (p ≤ 0.02), while trypsin (U/g protein; p = 0.02) demonstrated the opposite effect. No treatment effects were observed for maternal or foetal pancreatic insulin-containing cell clusters. Foetal serum insulin and glucose levels were reduced with advancing gestation (p ≤ 0.03). The largest maternal insulin-containing cell cluster was not influenced by advancing gestation, while foetal clusters grew throughout (p = 0.01). These effects indicate that maternal digestive enzymes are influenced by nutrient restriction and there is a potential for programming of increased foetal digestive enzyme production resulting from previous maternal nutrient restriction.

Carotid stent deformation: sonographic findings and CT correlation

Carotid artery dissection is a rare but potentially serious complication of endovascular procedures in the carotid arteries. Stent deformation or incomplete expansion may occur following endovascular repair of an iatrogenic carotid artery dissection and may mimic stent fracture. We report an unusual case of deformation of a common carotid artery open cell design stent following endovascular repair of an iatrogenic dissection, which resulted in persistent blood flow between the stent and the wall of the common carotid artery. Sonographic features are described and correlation with intravascular ultrasound and CT is provided.

Advances in transcranial Doppler US: imaging ahead

Transcranial Doppler ultrasonography (US) is a noninvasive, portable technique for evaluating the intracranial vasculature. It has found its most useful clinical application in the detection of vasospasm involving the cerebral vessels after subarachnoid hemorrhage due to aneurysm rupture. The technique has become an integral part of monitoring and managing patients with subarachnoid hemorrhage in the neurologic intensive care unit. In addition, it has proved useful for evaluating the intracranial vasculature in patients with sickle cell disease, stroke, or brain death. Transcranial US originated as a "blind" nonimaging study in which pulsed Doppler technology was used. Identification of the major intracranial vessels and evaluation of those vessels for vasospasm relied on spectral waveforms obtained in each vessel and was based on the depth of the vessel from the skull, the direction of blood flow, and the orientation of the transducer. Recent advances in US technology allow the use of gray-scale, spectral Doppler, and color Doppler flow imaging to directly visualize intracranial vessels, thereby simplifying flow velocity measurements and enhancing their accuracy for vasospasm detection. In particular, measurements of peak systolic velocity and mean flow velocity and calculation of the Lindegaard ratio facilitate the identification of vessels that may be in vasospasm and help differentiate vasospasm from physiologic conditions such as hyperemia and autoregulation. Thus, gray-scale and color Doppler flow imaging offer many advantages over the original pulsed Doppler technique for evaluating the intracranial vasculature.

Clinical review: Parathyroid localization and implications for clinical management

CLINICAL CONTEXT

The prevalence of hyperparathyroidism, especially primary hyperparathyroidism, has increased in recent decades due to improvements in diagnostic techniques with a corresponding surge in parathyroid surgery, leading to the development of focused, minimally invasive surgical approaches. Focused parathyroidectomy is predicated on preoperative localization of suspected parathyroid pathology. As a result, there has been a proliferation of parathyroid imaging modalities and protocols, resulting in confusion about their indications and applications.

EVIDENCE ACQUISITION

Bibliographies from clinical trials and review articles published since 2000 were reviewed and supplemented with targeted searches using biomedical databases. We also employed our extensive clinical experience.

EVIDENCE SYNTHESIS

The best-studied modalities for parathyroid localization are nuclear scintigraphy and sonography and are widely applied as initial studies. Multiple variations exist, and several additional noninvasive imaging techniques, such as computed tomography and magnetic resonance, are described. The exquisite anatomical detail of 4-dimensional computed tomography must be balanced with significant radiation exposure to the thyroid gland. Invasive venous PTH sampling and parathyroid arteriography have important roles in remedial cases. Due to considerable heterogeneity in imaging, multidisciplinary collaboration between endocrinologists, surgeons, and radiologists is beneficial.

CONCLUSIONS

Parathyroid localization is indicated in surgical candidates. Crucial considerations when selecting an imaging study include availability, cost, radiation exposure, local expertise, and accuracy. Additional factors include the patient's anticipated pathology and whether it is de novo or refractory disease. An approach to imaging for patients with primary hyperparathyroidism is presented.

Effects of plane of nutrition on in vitro fertilization and early embryonic development in sheep1

Nutrition has been shown to influence several reproductive functions, including hormone production, oocyte competence and fertilization, and early embryonic development. To determine the effects of maternal diet on in vitro fertilization (IVF) and early embryonic development, ewes (n = 18; 47.0 +/- 1.5 kg of initial BW) were divided into control and underfed (60% of control) nutritional planes for 8 wk before oocyte collection. Pelleted diets containing 2.4 Mcal of ME/kg and 13% CP (DM basis) were fed once daily. During the first 4-wk acclimation phase, control and underfed ewes were fed 1,000 and 600 g/d, respectively. From wk 4 to 8, control (adequate) ewes were fed to maintain BW and offered 720 g/d, whereas underfed ewes received 432 g/d (60% restricted). Synchronization of estrus was performed using progestagen sponges for 14 d. Follicular development was induced by twice daily injections of FSH on d 13 (5 units/injection) and 14 (4 units/injection) of the estrous cycle. Oocytes were collected from all visible follicles on d 15 of the estrous cycle. After IVF, the proportion of developing embryos was evaluated throughout an 8-d culture period. Under-nutrition decreased (P < 0.006) the rate of cleavage, number of blastocysts per ewe, and rate of blastocyst formation (from 79 to 64%; from 3.3 to 0.8; and from 31 to 8%, respectively). However, the number of visible follicles, total number of oocytes, number of healthy oocytes, percentage of healthy oocytes, number of cleaved oocytes, and morula formation per ewe were similar for control and underfed ewes. These data indicate that undernutrition of donor ewes, resulting in lower BW and BCS, has a negative effect on oocyte quality, which results in lower rates of cleavage and blastocyst formation.

Recruitment of TRADD, FADD, and caspase 8 to double-stranded RNA-triggered death inducing signaling complexes (dsRNA-DISCs)

Rapid elimination of virus-infected cells by apoptosis is an efficient anti-viral strategy. Double-stranded RNA (dsRNA), a viral product, is potently and rapidly apoptogenic in susceptible cells. Caspase 8 plays an important role in the dsRNA-induced apoptosis; however, the mechanisms of caspase 8 activation in response to dsRNA are unknown. We demonstrate here that, in HeLa cells, the dsRNA-triggered activation of caspase 8 is independent of ongoing proteins synthesis (and is, therefore, independent of changes in pro- and anti-apoptotic gene expression) and involves the formation of multiprotein dsRNA-triggered death inducing signaling complexes (dsRNA-DISCs). DsRNA-DISCs contain FADD, TRADD, and caspase 8; however, several experimental approaches suggest that death ligands and death receptors (such as Fas/Apo1 and DR4/Apo2) are not involved in the formation of dsRNA-DISCs.

A Modified Presynchronization Protocol Improves Fertility to Timed Artificial Insemination in Lactating Dairy Cows

To compare 2 hormonal protocols for submission of lactating dairy cows for timed artificial insemination (TAI), nonpregnant lactating Holstein cows (n = 269) >60 d in milk were randomly assigned to each of 2 treatments to receive TAI (TAI = d 0). Cows assigned to the first treatment (Ovsynch, n = 134) received 50 microg of GnRH (d -10), 25 mg of PGF2alpha (d -3), and 50 microg of GnRH (d -1) beginning at a random stage of the estrous cycle. Cows assigned to the second treatment (Presynch, n = 135) received Ovsynch but with the addition of 2 PGF2alpha (25 mg) injections administered 14 d apart beginning 28 d (d -38 and -24) before initiation of Ovsynch. All cows received TAI 16 to 18 h after the second GnRH injection. Ovulatory response after each GnRH injection for a subset of cows (n = 109) and pregnancy status 42 d after TAI for all cows were assessed using transrectal ultrasonography. Based on serum progesterone (P4) profiles determined for a subset of cows (n = 109), P4 concentrations decreased for Presynch cows after the first 2 PGF2alpha injections, and Presynch cows had greater P4 concentrations at the PGF2alpha injection on d -3 compared with Ovsynch cows. Although the proportion of cows ovulating after the first and second GnRH injections did not differ statistically between treatments (41.1 and 69.6% vs. 35.9 and 81.1% for Ovsynch vs. Presynch, respectively), pregnancy rate per artificial insemination (PR/AI) at 42 d post TAI was greater for Presynch than for Ovsynch cows (49.6 vs. 37.3%). Parity, DIM, and body condition score (BCS) at TAI did not affect PR/AI to TAI. These data support use of this presynchronization protocol to increase PR/ AI of lactating dairy cows receiving TAI compared with Ovsynch.

Effects of epidermal growth factor on early embryonic development after in vitro fertilization of oocytes collected from ewes treated with follicle stimulating hormone

Epidermal growth factor (EGF) has been shown to enhance the in vitro rate of blastocyst formation in several species. Follicular development was induced in ewes (n=15) by twice daily administration of FSH-P on Days 13 and 14 of the estrous cycle. Cumulus oocyte complexes (COCs) were collected from all visible follicles (n=25+/-2.4/ewe) on Day 15. COCs from each ewe were cultured separately for 24h in maturation medium (containing 10% serum, LH, FSH and estradiol) with (8.2+/-0.9 per ewe) or without (7.8+/-0.8 per ewe) EGF (10 ng/ml). Oocytes were then denuded by hyaluronidase treatment, and healthy oocytes were cultured in the presence of frozen-thawed semen in synthetic oviductal fluid (SOF) medium containing 2% sheep serum. After 18-20 h, zygotes were transferred to SOF medium without glucose and cultured for about 36 h until they reached the 4-8 cell stage. Embryos were transferred to SOF medium with glucose for further development. Medium was changed every other day until blastocyst formation on Day 8 of culture (Day 1=day of fertilization). The rate of embryonic development was evaluated throughout the culture period. After maturation, cumulus cells were more expanded in the presence than in the absence of EGF. The rates of fertilization (overall 75.7+/-3.9%) and morula formation (overall 40.6+/-7.1%) were similar (P>0.05) for COCs cultured with or without EGF. However, EGF increased (P<0.01) the number of blastocysts (1.4+/-0.1 versus 0.6+/-0.2 per ewe) and tended to increase (P<0.1) the rate of blastocyst formation (21.0+/-6.6% versus 13.4+/-4.3% per ewe). These data demonstrate that EGF increases blastocyst formation in FSH-treated ewes. Therefore, EGF is recommended as a supplement to maturation medium to enhance embryonic development in vitro in FSH-treated sheep.

Effects of follicle stimulating hormone (FSH) on follicular development, oocyte retrieval, and in vitro fertilization (IVF) in ewes during breeding season and seasonal anestrus

Administration of FSH increases the number of developing follicles, and affects oocyte health and cleavage rate. To determine the optimal level of FSH treatment, studies were conducted during the normal breeding season and seasonal anestrus. In Experiment 1, ewes were implanted with SyncroMate-B (SMB; norgestomet) for 14 days during the breeding season. Beginning on day 12 or 13 after SMB implantation, ewes were treated with saline (control; n=10), or treated with FSH for two days (2D; n=9) or three days (3D; n=10). In Experiment 2, conducted during seasonal anestrus, ewes were implanted with SMB for 14 days (n=23) or were not implanted (n=26). The SMB-implanted and nonimplanted ewes were assigned to one of three treatments as in Experiment 1: control (n=13), 2D (n=21) or 3D (n=15). In Experiments 1 and 2, ewes were laparotomized to count the number of follicles < or = 3 mm and > 3 mm and to retrieve oocytes. Healthy oocytes from each treatment were used for IVF. In Experiment 3, ewes (n=6) were implanted twice with SMB for 14 days during seasonal anestrus. Ewes were injected with FSH for 2 days, and the oocytes were collected and fertilized as in Experiments 1 and 2. In Experiment 1, FSH-treatment increased (P < 0.05) the number of follicles > 3 mm, the number of oocytes retrieved from follicles < or = 3 mm and > 3 mm, the proportion of healthy oocytes, and the number of oocytes used for IVF. Oocytes from control and 2D ewes had greater (P < 0.01) cleavage rates than 3D ewes (68% and 71% vs. 42%). In Experiment 2, implanted and nonimplanted ewes had similar (P > 0.05) numbers of follicles, total oocytes, and healthy oocytes; therefore, data were combined. The FSH treatment increased (P < 0.01) the number of follicles > 3 mm, and the number of oocytes recovered from follicles > 3 mm. The recovery rate of oocytes and the percentage of healthy oocytes were similar for control and FSH-treated ewes. The cleavage rate in Experiment 2 ranged from 4 to 16%. In Experiment 3, the cleavage rate for ewes treated twice with SMB was 27% which tended to be greater (P < 0.07) than for the 2D ewes that received one SMB implant in Experiment 2. These data indicate that FSH increased the number of developing follicles and the number of healthy oocytes retrieved from ewes during the breeding season and seasonal anestrus. However, cleavage rates during seasonal anestrus were lower than during the normal breeding season in both FSH-treated and control ewes. Treatment of ewes for 2 days with FSH resulted in a greater cleavage rate than treatment of ewes for 3 days.

Effect of crambe meal on performance, reproduction, and thyroid hormone levels in gestating and lactating beef cows

Crambe meal was compared to a combination of sunflower and soybean meal as a protein supplement for mature beef cows in two experiments. In Exp. 1, cows (n = 80, average BW 651+/-14.4 kg) were fed crambe meal at 9.86% of dry matter intake (DMI) during the last trimester of gestation. No differences (P < .05) were detected due to treatment for cow weight, condition score, thyroid hormones, calf birth weight, or calving interval. In Exp. 2, cows (n = 100, average BW 566+/-6.82 kg) were fed crambe meal at 7.44% of DMI during the last trimester of gestation and at 8.33% of DMI during early lactation (53+/-6 d of lactation). Gains were greater during gestation (P = .09) and throughout the supplementation period (P = .06), and days to first estrus were reduced (P < .01) for cows fed crambe meal. During lactation, serum triiodothyronine (T3) concentrations did not decline as much (P = .03) in cows fed crambe meal as in cows fed sunflower-soybean meal-based supplements. No differences (P > .10) were apparent for condition score, birth weight, calf growth rate, weaning weight, thyroid hormones during gestation, or calving interval. These data indicate that crambe meal fed at the levels used in this experiment can be used as a protein supplement for beef cows without negatively affecting cows' performance.

Undegraded intake protein supplementation: II. Effects on plasma hormone and metabolite concentrations in periparturient beef cows fed low-quality hay during gestation and lactation

Hereford x Angus cows (n = 36; initial wt 568+/-59 kg) were used to evaluate the effects of undegradable intake protein (UIP) supplementation on plasma hormone and metabolite concentrations. Treatments were control (unsupplemented) or one of three protein supplements. Supplements were fed at 1.3 kg DM/d and included UIP at low, medium, or high levels (53, 223, or 412 g UIP/kg supplement DM, respectively). Supplements were formulated to be isocaloric (1.77 Mcal NEm/kg) and to contain equal amounts of degradable intake protein (DIP; 211 g DIP/kg supplement DM). Prairie hay (5.8% CP) was offered for ad libitum consumption. Jugular blood samples were collected daily from each cow during six 7-d collection periods (corresponding to mo 7, 8, and 9 of gestation and to mo 1, 2, and 3 of lactation). Plasma glucose concentrations were similar between control and supplemented cows during mo 2 and 3 of lactation; however, the low UIP treatment group had consistently higher plasma glucose (P< or =.02) than cows fed medium or high UIP supplements during gestation and the last month of lactation. During gestation, cows fed the high UIP supplement had higher (P< or =.08) plasma glucose than cows fed the medium UIP supplement. During gestation, plasma insulin concentration was increased (P = .01) by supplementation; insulin also increased (P<.01; mo 8 and 9) as supplemental UIP increased. During lactation, plasma insulin was greater (P = .01) in supplemented than in control cows. During mo 2 and 3 of lactation, insulin was lower (P< or =.04) in cows fed low UIP supplement compared with cows fed medium or high UIP supplements. Growth hormone concentration was higher (P< or =.03) in control cows than in supplemented cows in all periods measured except mo 7 of gestation. Plasma nonesterified fatty acid concentrations were higher (P< or =.03) in control cows than in supplemented cows in all periods measured except the 1st mo of lactation. These data are interpreted to suggest that protein supplementation and level of UIP can alter plasma concentrations of hormones and metabolites in gestating and lactating beef cows consuming low-quality hay.

Nondestructive tablet hardness testing by near-infrared spectroscopy: a new and robust spectral best-fit algorithm

A new algorithm using common statistics was proposed for nondestructive near-infrared (near-IR) spectroscopic tablet hardness testing over a range of tablet potencies. The spectral features that allow near-IR tablet hardness testing were evaluated. Cimetidine tablets of 1-20% potency and 1-7 kp hardness were used for the development and testing of a new spectral best-fit algorithm for tablet hardness prediction. Actual tablet hardness values determined via a destructive diametral crushing test were used for construction of calibration models using principal component analysis/principal component regression (PCA/PCR) or the new algorithm. Both methods allowed the prediction of tablet hardness over the range of potencies studied. The spectral best-fit method compared favorably to the multivariate PCA/PCR method, but was easier to develop. The new approach offers advantages over wavelength-based regression models because the calculation of a spectral slope averages out the influence of individual spectral absorbance bands. The ability to generalize the hardness calibration over a range of potencies confirms the robust nature of the method.

Injection of MK-801 affects ocular dominance shifts more than visual activity

Kittens were given intramuscular injections of the N-methyl--aspartate (NMDA) antagonist MK-801 twice daily (morning and midday) during the peak of the period of susceptibility for ocular dominance changes. They were then exposed to light with one eye closed for 4 h after each injection. The ocular dominance of these kittens was shifted significantly less than that of kittens injected with saline and exposed to light over the same period at the same age. After recording a sample of cells for an ocular dominance histogram, the kittens were injected with the same dose of MK-801 that was used during rearing to observe its effect on the activity of single cells in the visual cortex. In the majority of cells (7/13) there was no significant change in activity. Positive evidence for a reduction in activity was seen in only a minority (3/13) of cells. In a separate series of experiments, dose-response curves were measured for cells in the visual cortex in response to iontophoresis of NMDA or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), and the effect of an injection of MK-801 on these curves was measured. MK-801, at doses similar to those used in the ocular dominance experiments, had a significant effect on the dose-response curves for NMDA, but little effect on the dose-response curves for AMPA, or the visual responses of the cells. We conclude that ocular dominance shifts can be reduced significantly by a treatment that has little effect on the level of activity of cells in the visual cortex but does specifically affect the responses of the cells to NMDA as opposed to the responses to AMPA.

Time-course of the uterine response to estradiol-17beta in ovariectomized ewes: uterine growth and microvascular development

The time-course of uterine growth, cell proliferation, and microvascular development was evaluated during the first 72 h after implanting estradiol-17beta (E2) into ovariectomized (OVX) ewes. Uterine fresh weight increased 2.3-fold by 24 h and increased further (3.3-fold) by 48 h. The majority (approximately 75%) of this growth response was associated with tissue growth rather than a change in the tissue dry weight:fresh weight ratio. Both uterine cell number (DNA content) and cell size (RNA:DNA ratio) increased from 0 to 24 h (1.8-fold and 1.7-fold, respectively). Cell proliferation also increased dramatically between 8 h and 24 h after E2 implantation. Endometrial microvascular volume density (percentage of tissue volume occupied by microvessels) increased approximately 1.8-fold by 24 h and then remained constant or declined slightly through 72 h. The total endometrial microvascular volume, however, increased approximately 5-fold from 0 to 24 h and increased further by 72 h. Thus, treatment of OVX ewes with E2 caused a dramatic increase in uterine fresh and dry weights by 24 h, due primarily to hyperplasia and hypertrophy, with only a relatively small change in tissue dry weight:fresh weight ratio. This dramatic uterine growth was associated with a profound increase in endometrial microvascular volume.

Time-course of the uterine response to estradiol-17beta in ovariectomized ewes: expression of angiogenic factors

Uterine expression of angiogenic factors (vascular endothelial growth factor [VEGF] and basic fibroblast growth factor [bFGF]) was evaluated in ovariectomized ewes at 0, 2, 4, 8, 24, 48, or 72 h after estradiol (E2) treatment. Endometrial VEGF mRNA increased more than 5-fold from 0 to 4 h, remained elevated at 8 h, and then declined through 72 h after E2 treatment. In contrast, endometrial bFGF mRNA remained constant from 0 to 4 h, increased 2.2-fold from 4 to 8 h, remained elevated at 24 h, and then declined through 72 h. Immunostaining for VEGF was present in myometrial and endometrial microvessels (arterioles, venules, and/or capillaries) and also in myometrial smooth muscle; the pattern of VEGF immunostaining followed that of mRNA expression, being elevated at 4 and 8 h after E2 treatment. Immunostaining for bFGF was present exclusively in uterine glands; the pattern of bFGF immunostaining also followed that of its mRNA, being elevated at 8 and 24 h after E2. On the basis of these observations, we suggest that VEGF and bFGF are probably important factors responsible for the dramatic uterine microvascular response that occurs 8 to 24 h after E2 treatment in ovariectomized ewes.

Gap junctional intercellular communication of bovine luteal cells from several stages of the estrous cycle: effects of prostaglandin F2 alpha, protein kinase C and calcium

Cellular interactions mediated by both contact-dependent and contact-independent mechanisms are probably important to maintain luteal function. The present studies were performed to evaluate the effects of luteotropic and luteolytic hormones, and also intracellular regulators, on contact-dependent gap junctional intercellular communication (GJIC) of bovine luteal cells from several stages of luteal development. Bovine corpora lutea (CL) from the early, mid and late luteal phases of the estrous cycle were dispersed with collagenase and incubated with no treatment, LH, PGF or LH + PGF (Experiment 1), or with no treatment, or agonists or antagonists of protein kinase C (TPA or H-7) or calcium (A23187 or EGTA; Experiment 2). After incubation, media were collected for determination of progester-one concentrations. Then the rate of GJIC was evaluated for small luteal cells in contact with small luteal cells, and large luteal cells in contact with small luteal cells by using the fluorescence recovery after photobleaching technique and laser cytometry. Luteal cells from each stage of the estrous cycle exhibited GJIC, but the rate of GJIC was least (P < 0.05) for luteal cells from the late luteal phase. LH increased (P < 0.05) GJIC between small luteal cells from the mid and late but not the early luteal phase. PGF increased (P < 0.05) GJIC between small luteal cells from the mid luteal phase and diminished (P < 0.05) LH-stimulatory effects on GJIC between small luteal cells from the late luteal phase. Throughout the estrous cycle, TPA decreased (P < 0.05) the rate of GJIC between large and small, and between small luteal cells, and A23187 decreased (P < 0.05) the rate of GJIC between large and small luteal cells. LH and LH + PGF, but not PGF alone increased (P < 0.05) progesterone secretion by luteal cells from the mid and late luteal phases. Agonists or antagonists of PKC or calcium did not affect progesterone secretion by luteal cells. These data demonstrate that both luteal cell types communicate with small luteal cells, and the rate of communication depends on the stage of luteal development. LH and PGF affect GJIC between small luteal cells during the fully differentiated (mid-luteal) and regressing (late luteal) stages of the estrous cycle. In contrast, at all stages of luteal development, activation of PKC decreases GJIC between small and between large and small luteal cells, whereas calcium ionophore decreases GJIC only between large and small luteal cells. Luteotropic and luteolytic hormones, and intracellular regulators, may be involved in regulation of cellular interactions within bovine CL which likely is an important mechanism for coordination of luteal function.

Gap junctional intercellular communication of bovine luteal cells from several stages of the estrous cycle: effects of cyclic adenosine 3',5'-monophosphate

Cellular interactions mediated by both contact-dependent and contact-independent mechanisms are probably important to maintain luteal function. The objective of the present study was to evaluate the role of cAMP in regulation of contact-dependent gap junctional intercellular communication (GJIC) of bovine luteal cells from several stages of luteal development. In experiment 1, corpora lutea (n = 5) from the mid-luteal phase of the estrous cycle were dissociated with collagenase, and cells were preincubated in a medium with serum. Then the medium was changed to serum-free media containing a cAMP agonist (dbcAMP; 1 mM) or antagonist (Rp-cAMPS; 0, 3, 10, 30, or 100 microM). In experiment 2, corpora lutea from the early (n = 7), mid- (n = 6), and late (n = 6) luteal phases of the estrous cycle were dissociated and preincubated as in experiment 1, and luteal cells were then incubated with no treatment, LH (100 ng/ml), dbcAMP (1 mM), forskolin (1 microM), Rp-cAMPS (100 microM), or LH+Rp-cAMPS. After incubation of luteal cells with treatments for 18-24 h, media were collected for determination of progesterone and cAMP concentrations. Then the rate of GJIC was evaluated for selected cells (small luteal cells in contact with small luteal cells, and large luteal cells in contact with small luteal cells) by using the fluorescence recovery after photo-bleaching technique and laser cytometry. In experiment 1, dbcAMP increased (p < 0.01) but Rp-cAMPS (p < 0.05) decreased GJIC between small luteal cells and between large and small luteal cells. In addition, dbcAMP stimulated (p < 0.01) but Rp-cAMPS did not affect progesterone secretion. In experiment 2, treatments affected (p < 0.05) GJIC and progesterone production of luteal cells from the mid- and late but not from the early luteal phase of the estrous cycle. GJIC between small luteal cells was increased (p < 0.01) by LH, dbcAMP, and forskolin. GJIC between large and small luteal cells was increased (p < 0.05) by dbcAMP and forskolin. Rp-cAMPS decreased (p < 0.01) GJIC between small luteal cells (mid-luteal phase) and between large and small luteal cells (mid- and late luteal phases). In addition, Rp-cAMPS inhibited (p < 0.05) the stimulatory effects of LH on GJIC between small luteal cells from the mid- and late luteal phases of the estrous cycle. For luteal cells from the mid- and late luteal phases, progesterone production was increased (p < 0.05) by LH, dbcAMP, forskolin, and LH+Rp-cAMPS, but was not affected by Rp-cAMPS. Across all stages of the estrous cycle, cyclic AMP accumulation in media was greater (p < 0.05) in LH- and forskolin-treated cultures than in control cultures and was greater (p < 0.01) in forskolin-treated than in LH-treated cultures. These data demonstrate that small and large luteal cells communicate with each other and that the rate of GJIC is modulated by LH and cAMP, as has been shown previously for other cell types. Thus, cAMP appears to be involved in the regulation of GJIC within the bovine corpus luteum, which probably is an important mechanism for coordinating luteal cell function.

Near-infrared spectroscopic monitoring of the film coating process

PURPOSE

The purpose of this study was to investigate the potential of near-infrared (near-IR) spectroscopy for non-destructive at-line determination of the amount of polymer coat applied to tablet cores in a Wurster column.

METHODS

The effects of coating composition on the near-IR spectroscopic determination of ethylcellulose (Aquacoat ECD-30) or hydroxypropylmethylcellulose (HPMC)-based (Spectrablend) coating were evaluated, as were the performance of several chemometric techniques.

RESULTS

Tablets were coated with up to 30% ethylcellulose or 22% HPMC, and samples were pulled at regular intervals during each coating run. Near-IR reflectance spectra of the intact tablets were then collected. The spectra were preprocessed by multiplicative scatter correction (MSC) or second derivative (D2) calculations, and calibrations developed using either principal components (PCs) or multiple spectral wavelengths. The near-IR method provided predictions of film applied with standard errors of 1.07% w/w or less.

CONCLUSIONS

Near-IR spectroscopy can be profitably employed in a rapid and non-destructive determination of the amount of polymer film applied to tablets, and offers a simple means to monitor the film coating process.

Transient immunoglobulin-like molecules are present in the subplate zone and cerebral cortex during postnatal development

A monoclonal antibody (mAb SP-1) labels subplate neurons of the cat visual cortex but does not stain the remnants of the subplate neuronal population that comprise the interstitial cells of adult cortical white matter. mAb SP-1 was shown previously to recognize a cytosolic polypeptide of 56 kDa (Naegele et al., 1991). We have now characterized the distribution of SP-1 immunoreactive neurons in the visual cortex and carried out additional biochemical studies at a range of postnatal ages in various tissues. Brain, liver and serum were found to contain the previously identified 56 kDa polypeptide. This polypeptide was also recognized by a cat immunoglobulin antiserum. The epitope recognized by mAb SP-1 was present on cat IgG Fc fragment but not cat IgG Fab fragment. By 4 weeks postnatal, levels of the 56 kDa antigen decreased in cortex and an additional higher molecular weight SP-1 reactive polypeptide of 75 kDa was detected. In the mature cortex, both polypeptides were absent from cytosolic fractions. Immunocytochemical staining comparing the distributions of SP-1 (SP-1+) and anti-IgG (Ig+) immunoreactive neurons showed complete colocalization in subplate neurons beneath primary visual cortex. By 4 weeks, some pyramidal neurons in cortical areas 17 and 18 were weakly positive for SP-1 but negative for IgG. At subsequent ages, the immunoreactive staining became progressively fainter until it was no longer detectable in white or gray matter of adult cat visual cortex.

Determination of film-coated tablet parameters by near-infrared spectroscopy

Near-infrared (near-IR) spectroscopy was used in the determination of three parameters of theophylline tablets film-coated with ethylcellulose. Spectra of individual intact tablets were collected on two near-IR spectrometers: a grating-based spectrometer, and an acousto-optic tunable filter spectrometer. Calibrations were developed for the prediction of the time to 50% dissolution (t50%) of theophylline for tablets of varying coat thickness, for the determination of the thickness of the ethylcellulose coat applied, and for the prediction of the hardness of coated tablets. Principal component analysis was performed on the spectra prior to calibration development. The standard errors of calibration (SEC) and prediction (SEP) for determination of dissolution rates were 2.8 and 6.6 min, respectively. The SEC for the coating thickness calibration was 0.0002 inches, with an SEP of 0.00024 inches, and the SEC and SEP for the determination of tablet hardness were 0.54 and 0.62 kilopons, respectively.

Carotid artery occlusion: positive predictive value of duplex sonography compared with arteriography

PURPOSE

Duplex ultrasonography is an accurate, noninvasive method for diagnosing, characterizing, and classifying atherosclerotic stenoses of the extracranial carotid artery system. To date, however, no large series has studied the predictive value of duplex sonography in the diagnosis of carotid artery occlusion, an important consideration, given the marked difference in clinical treatment between patients with high-grade stenosis (surgical therapy) and those with occlusive disease (nonsurgical therapy).

METHODS

We retrospectively reviewed 158 patients with 174 occluded carotid artery segments (examined over a 6 1/2-year period) to determine the predicative value of duplex sonography in differentiating carotid artery occlusion from high-grade stenosis.

RESULTS

All patients had arteriographic correlation. Duplex ultrasonography had a positive predictive value of 92.5% (7.5% false-positive rate; 95% confidence interval, 3.6% to 11.4%) in establishing a diagnosis of carotid artery occlusion. Further analysis revealed no significant improvement in the false-positive rate with the addition of color Doppler flow imaging to high-resolution B-mode scanning and pulsed Doppler spectral analysis. Predictive value increased to 96.7% (95% confidence interval, 90.7% to 99.3%) over the last 2 years of the study, a statistically significant improvement.

CONCLUSIONS

We believe that duplex ultrasonography is an acceptably accurate method for diagnosing carotid arterial occlusion in most patients. Arteriography should be reserved for patients with symptoms who are surgical candidates to identify those who may still have a surgically correctable high-grade stenosis.

Injection of doxorubicin into rabbit eyelid does not result in loss of facial motor neurons

In both laboratory and clinical studies, injection of doxorubicin directly into the eyelid results in permanent muscle loss of the majority of fibers within treated eyelids. A first clinical trial of this technique in blepharospasm and hemifacial spasm patients has been performed. All patients who completed a full course of doxorubicin treatment showed a permanent decrease in eyelid strength, with over 50% of these patients requiring no further treatment. Doxorubicin is known to be carried by retrograde axonal transport to the brain and is a known neurotoxin. This raises the question of the effect of these treatments on the facial neurons which innervate the orbicularis oculi muscle in the eyelids. The effect on the number of facial neurons present after injection of doxorubicin into the eyelid of rabbits was determined using both HRP and diI retrograde labeling techniques. Despite the extensive and permanent muscle loss caused by the doxorubicin treatments, there was no measurable loss of facial neurons on the doxorubicin treated sides. DiI was shown to be myotoxic at high concentrations and amplified the myotoxic effect of doxorubicin. Lack of neuronal loss may offer assurance of clinical safety to the facial motor neurons of muscle spasm patients who receive doxorubicin injections into their eyelids.

Studies of FSH-P induced follicular growth in cows

Because cow ovaries do not contain a dominant follicle before Day 3 of the estrous cycle, we hypothesized that gonadotropin treatment early in the estrous cycle would induce growth of multiple follicles and could be used to induce superovulation. In Experiment 1, when 16 cows were treated with FSH-P beginning on Day 2 of the estrous cycle and were slaughtered on Day 5, all cows responded to gonadotropin treatment by exhibiting a large number ( approximately 19) of estrogenactive follicles >/= 6 mm. In Experiment 2, in response to FSH-P treatment from Day 2 to Day 7, and fenprostalene treatment on Day 6, 11 of 15 cows exhibited estrus and had a mean ovulation rate of 23.7 +/- 1.5. In Experiment 3, an FSH-P treatment regimen identical to that used in Experiment 2 was administered to cows beginning either on Day 2 (Day-2 cows; n=14) or Day 10 (Day-10 cows; n=11) of the estrous cycle. Twelve of 14 Day-2 cows and all Day-10 cows exhibited estrus after fenprostalene treatment. Day-2 cows exhibited 34.3 +/- 7.0 ovulations, which was less (P < 0.05) than that exhibited by Day-10 cows (48.3 +/- 4.4). However, the proportion of embryos recovered per corpus luteum was about 2-fold greater (P < 0.05) for Day-2 cows than for Day-10 cows (0.49 +/- 0.08 vs 0.27 +/- 0.06). These data indicate that beginning gonadotropin treatment early in the estrous cycle, when a dominant follicle is not present, provides an efficacious means to induce growth of multiple follicles and superovulation in cows. However, when FSH was administered for 6 d, beginning the treatment on Day 10 also resulted in a consistent and efficacious response.

Production of mitogenic factors by cell types of bovine large estrogen-active and estrogen-inactive follicles

This study investigated whether large follicles (estrogen-active and estrogen-inactive) of cows produce factors with mitogenic activity. Large, preovulatory follicles (greater than or equal to 9 mm in diameter) were classified as estrogen-active or -inactive based on ratio of estrogen: progesterone concentrations in follicular fluid. After incubation of granulosa cells and thecal tissues from follicles, granulosa cell conditioned media (GCM), thecal conditioned media (TCM) and follicular fluid (FFL) were evaluated for effects on proliferation of bovine aortic endothelial (BAE) and BALB/3T3 (3T3) cells. Pools of GCM, TCM and FFL stimulated proliferation of BAE and 3T3 in a dose-dependent fashion. Across all follicles (n = 20), GCM had greater stimulatory effect on proliferation of BAE than on proliferation of 3T3 (135 vs 115% of unconditioned media controls), whereas TCM stimulated proliferation of BAE and 3T3 to a similar extent (128 and 128%). Across type (GCM and TCM) of conditioned media, estrogen-active follicles stimulated proliferation of BAE more than proliferation of 3T3 (137 vs 121% of unconditioned media controls), whereas estrogen-inactive follicles stimulated proliferation of BAE and 3T3 to a similar extent (120 vs 122%). As observed for GCM, FFL across all follicles had a greater stimulatory effect on proliferation of BAE than on proliferation of 3T3 (159 vs 141%). Granulosa-conditioned media stimulated proliferation of BAE and 3T3 only when obtained from estrogen-active follicles; mitogenic activities of TCM and FFL were not influenced by type of follicle. These data demonstrate that granulosa cells of large preovulatory bovine follicles secrete a mitogenic factor(s) that is more stimulatory for proliferation of BAE than for 3T3.(ABSTRACT TRUNCATED AT 250 WORDS)

Growth and in-vitro metabolism of placental tissues of cows from day 100 to day 250 of gestation

Weight of placental tissues of cows increased exponentially from Day 100 to Day 250 of gestation, but at much slower relative and absolute rates than fetal weight. In addition, growth rate of fetal placental tissues was less than that of maternal placental tissues. Concentrations of DNA, RNA and protein, however, increased in fetal placental but not in maternal placental tissues. Fetal placental tissues therefore exhibited hyperplasia, which probably contributes to increased functional capacity of the placenta during late gestation. The rate of O2 uptake in vitro was greatest for maternal placental tissues, suggesting that the maternal portion of the placenta accounts for most of the large rate of placental O2 utilization in vivo. Compared with other placental tissues, rate of secretion of macromolecules by intercaruncular endometrium was high, but decreased from Day 100 to 250, suggesting that uterine glandular secretory activity may decrease as gestation advances. Rate of secretion of macromolecules also was high for intercotyledonary tissues and increased with day of gestation, suggesting a role for secretory products of chorioallantois in gravid uterine function.

Prostaglandin F2 alpha, oxytocin and progesterone secretion by bovine luteal cells at several stages of luteal development: effects of oxytocin, luteinizing hormone, prostaglandin F2 alpha and estradiol-17 beta

Bovine luteal cells from Days 4, 8, 14 and 18 of the estrous cycle were incubated for 2 h (1 x 10(5) cells/ml) in serum-free media with one or a combination of treatments [control (no hormone), prostaglandin F2 alpha (PGF), oxytocin (OT), estradiol-17 beta (E) or luteinizing hormone (LH)]. Luteal cell conditioned media were then assayed by RIA for progesterone (P), PGF, and OT. Basal secretion of PGF on Days 4, 8, 14 and 18 was 173.8 +/- 66.2, 111.1 +/- 37.8, 57.7 +/- 15.4 and 124.3 +/- 29.9 pg/ml, respectively. Basal release of OT and P was greater on Day 4 (P less than 0.01) than on Day 8, 14 and 18 (OT: 17.5 +/- 2.6 versus 5.6 +/- 0.7, 6.0 +/- 1.4 and 3.1 +/- 0.4 pg/ml; P: 138.9 +/- 19.5 versus 23.2 +/- 7.5, 35.4 +/- 6.5 and 43.6 +/- 8.1 ng/ml, respectively). Oxytocin increased (P less than 0.01) PGF release by luteal cells compared with control cultures irrespective of day of estrous cycle. Estradiol-17 beta stimulated (P less than 0.05) PGF secretion on Days 8, 14 and 18, and LH increased (P less than 0.01) PGF production only on Day 14. Prostaglandin F2 alpha, E and LH had no effect on OT release by luteal cells from any day. Luteinizing hormone alone or in combination with PGF, OT or E increased (P less than 0.01) P secretion by cells from Days 8, 14 and 18. However on Day 8, a combination of PGF + OT and PGF + E decreased (P less than 0.05) LH-stimulated P secretion. These data demonstrate that OT stimulates PGF secretion by bovine luteal cells in vitro. In addition, LH and E also stimulate PGF release but effects may vary with stage of estrous cycle.

Angiogenic activity of maternal and fetal placental tissues of ewes throughout gestation

In Study 1, explants of caruncular and intercaruncular endometrium and fetal membrane were collected from ewes (5-6/day) on Days 11-13, 16-18 and 21-23 after mating and Days 10-12 after oestrus, and incubated for 24 h. Explant-conditioned media were evaluated for their effects on endothelial cell proliferation. Both caruncular and intercaruncular endometrium secreted factor(s) which stimulated endothelial cell proliferation, and which appeared to be greater than 100 x 10(3) Mr and heat-labile. In Study 2, conditioned media from explant incubations of caruncular and intercaruncular endometrium, cotyledon and intercotyledonary fetal membrane obtained from ewes (6-7/day) on Days 40, 65, 90, 115 and 140 after mating were evaluated for their effects on endothelial cell proliferation. Caruncular and intercaruncular endometrium and intercotyledonary fetal membrane secreted factor(s) which inhibited endothelial cell proliferation. Media from cotyledonary explants tended to stimulate endothelial cell proliferation on Day 115. Conditioned media from cotyledonary explants obtained from 3 additional ewes at Day 120 of gestation stimulated endothelial cell proliferation, and this activity also appeared to be greater than 100 x 10(3) Mr. Placental angiogenesis in ewes therefore appears to be modulated by both maternal and fetal placental tissues via stimulatory and inhibitory factors.

CT diagnosis of traumatic pericardium rupture

A case of traumatic rupture of the pericardium secondary to a motor vehicle accident is presented. Diagnosis of this condition was made prior to surgery by CT.

Angiogenic activity of bovine corpora lutea at several stages of luteal development

Samples from corpus haemorrhagicum, mid-cycle corpus luteum (CL) and late-cycle CL were tested for their abilities to stimulate neovascularization of chorioallantoic membranes (CAM) of developing chicks. Responses were graded from 0 to 4 (4 being the greatest response). Luteal tissue implants from each stage of the oestrous cycle stimulated growth of CAM blood vessels, and vascular responses increased with age of CL. Implants from late-cycle CL were typically graded 3 or 4. Luteal tissues from several stages of development were also incubated for 6 h in serum-free medium containing no hormone, LH, PGF-2 alpha or both hormones. Media conditioned by luteal tissues were assayed for progesterone and tested for their ability to stimulate mitogenesis and migration of bovine aortic endothelial cells in vitro. All media conditioned by luteal tissues stimulated mitogenesis and migration of endothelial cells, but media from late-cycle CL exhibited the greatest activity. Luteinizing hormone significantly increased in-vitro secretion of a factor(s) that stimulated migration of endothelial cells. PGF-2 alpha alone had no effect on production of endothelial cell mitogen or migration-stimulating factor(s) from luteal incubations; however, the ability of LH to enhance secretion of the migration-stimulating factor(s) was blocked by PGF-2 alpha. This study demonstrates that angiogenic activity of bovine luteal tissues increases with age of the CL and in-vitro secretion of angiogenic factor is responsive to hormones known to regulate luteal function.

Angiogenic activity of placental tissues of cows

In Exp. 1, maternal (caruncle) and fetal (cotyledon) portions of the placenta as well as uterine endometrium were obtained from cows at mid-gestation and evaluated for angiogenic activity by placing tissue samples on chick chorioallantoic membranes (CAM). Only caruncular tissues exhibited angiogenic activity in the CAM assay. In Exp. 2, lyophilized homogenates of caruncular tissues obtained from cows at mid-gestation were evaluated for angiogenic activity on CAM and for their ability to stimulate mitosis of bovine aortic endothelial cells in vitro. Homogenates of caruncular tissues again were angiogenic on the CAM and also were mitogenic for endothelial cells. In Exp. 3, maternal (caruncle and endometrium) and fetal (cotyledon and fetal membrane) portions of the placenta were obtained from cows at mid-gestation and fine minces (explants) of each were cultured for 24 h. Explant-conditioned media were then tested for angiogenic activity by their abilities to stimulate mitosis and migration of bovine aortic endothelial cells in vitro. Conditioned media from caruncular explants, but not from explants of other tissues, exhibited both mitogenic and migration-stimulating activities. When pools of caruncular explant-conditioned media were fractionated by ultrafiltration, mitogenic activity was not present in fractions of Mr less than 10,000, less than 30,000 and less than 100,000, but was retained in fractions of Mr greater than 10,000, greater than 30,000 and greater than 100,000. Mitogenic activity was not observed in any fractions subjected to heat treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

The postweaning rise of tonic luteinizing hormone secretion in anestrous cows is not prevented by chronic milking or the physical presence of the calf

The objective of the following study was to examine the ability of frequent milking, the physical presence of the calf, and their combination to prevent a postweaning rise in tonic luteinizing hormone (LH) secretion, estrus, and ovulation. Thirty Hereford cows were allowed to suckle their calves ad libitum until 17-21 days post partum and confirmed as anestrus. They were then assigned alternately by order of calving to 1 of 5 treatment groups: (1) Suckled (S) ad libitum; (2) Nonsuckled (NS)--calf removed for 102 h; (3) Nonsuckled--calf present (NSC)--calf remained with cow, but muzzled to prevent suckling for 102 h; (4) Nonsuckled--milked 8 times a day (NSM)--calf removed for 102 h and cow hand-milked for 10 min every 2 h from 0700 to 2100 h; (5) Nonsuckled--calf present--milked 8 times a day (NSMC)--combination of 3 and 4. Luteinizing hormone secretion patterns, estrous activity, and ovulation were monitored throughout the experiment. Prior to treatment (Day 0), mean pulse frequency (pulses/6 h), mean concentrations (ng/ml), and median concentrations (ng/ml) of LH did not differ (p greater than 0.45) between groups, and were 0.7 +/- 0.15, 2.8 +/- 0.14, and 2.6 +/- 0.11, respectively. Marked rises (p less than 0.01--p less than 0.03) in LH pulse frequency were observed in all groups except S between 48 and 54 h after onset of treatment. Mean and median concentrations of LH were lower (p less than 0.02) in S cows than in all other groups at 48-54 h.(ABSTRACT TRUNCATED AT 250 WORDS)