A randomized trial to compare smooth monofilament suture vs. barbed suture using the three-layer continuous closure technique in canine ovariohysterectomy in a high-quality high-volume spay/neuter clinic

The primary objective of this study was to compare time efficiency and complication rates between smooth monofilament suture (SMS) and barbed suture (BS) using the three-layer continuous incisional closure pattern after ovariohysterectomy in a high-quality high-volume spay/neuter clinic. The study was designed as a randomized controlled trial enrolling 71 adult female dogs. Dogs were randomly assigned to SMS or BS treatments. The effect of closure with BS or SMS on closure time was tested through multilevel, multivariable linear regression in a generalized linear mixed model. Body condition score, weight, and pre-closure incision length were tested as covariates. Surgeon was included in the model as a random effect. Pre-closure incision length (p = 0.01) and method (p ≤ 0.0001) were associated with closure time. Adjusting for pre-closure incision length, the average time for closure with SMS was 6.5 min (range 3.70-10.31 min), and the average time for closure with BS was 4.91 min (range 3.05-8.05 min). Accounting for the closure method, the closure time increased by 39 s for each additional centimeter of incision length. BS was more efficient than SMS when performing the three-layer continuous suture pattern. No short-term telemedicine-assessed complications were noted with either treatment method. BS can improve efficiency in surgical closures, especially considering large volumes of animals, and appears to have a similar short-term, telemedicine-assessed complication rate when compared to SMS.

Epidemiology's Adoption of System Dynamics is a Natural Extension of Population Thinking

Epidemiologists have adopted systems thinking as an approach to understanding why health conditions occur in animal populations beyond the knowledge of simple linear relationships. Beef production systems are complex adaptive systems and decisions and policies throughout the system can positively or negatively affect the health of cattle. Those decisions may occur far removed in time or place from the health event and may be logical in the context of other factors in the system. Causal loop diagrams and stock and flow models are tools for sharing and testing thoughts about the ways systems might behave.

Sedation with dexmedetomidine is associated with transient gallbladder wall thickening and peritoneal effusion in some dogs undergoing abdominal ultrasonography

Background

Dexmedetomidine often is used for sedation before or during abdominal ultrasonography. The effect of dexmedetomidine on gallbladder wall thickness is unknown.

Hypothesis/Objectives

To investigate the relationship between dexmedetomidine administration and gallbladder wall thickening in dogs. The hypothesis was that sedation with dexmedetomidine will cause transient gallbladder wall thickening. Gallbladder wall thickness will be associated with duration of sedation and recumbency position.

Animals

Seventy‐nine client owned dogs and 10 healthy research dogs.

Methods

A prospective observational study (n = 79) was used to establish the prevalence of gallbladder wall thickening (> 2.0 mm) after sedation with dexmedetomidine. A randomized, crossover study (n = 10) was used to evaluate the effect of time and recumbency position on the development of gallbladder wall thickening. Linear mixed models were used.

Results

The proportion of client‐owned dogs that developed gallbladder wall thickening was 24.05% (19/79; 95% confidence interval [CI], 15.1%‐35.0%) with a median dose of dexmedetomidine of 5.0 μg/kg (range, 2.0‐12.5 μg/kg). After sedation, the proportion of research dogs that developed gallbladder wall thickening in left lateral (5/10, 50%; 95% CI, 18.7%‐81.3%) and dorsal (7/10, 70%; 95% CI, 34.8%‐93.3%) recumbency did not differ significantly (P = .45). Gallbladder wall thickening developed within 20 to 40 minutes. Duration of sedation was significantly associated with thickening of the gallbladder wall (P < .001). Five dogs developed 9 instances of peritoneal effusion in both lateral (5) and dorsal (4) recumbency.

Conclusions and Clinical Importance

Sedation with dexmedetomidine is associated with gallbladder wall thickening (> 2.0 mm) and peritoneal effusion that could be confused with pathologic etiologies.

Factors associated with rabies vaccination of dog shelter staff in the United States

US animal shelters house and care for dogs with unknown medical histories. Such unknown medical backgrounds pose concern for zoonotic transmission of diseases to the shelter staff. One important zoonotic exposure is to rabies virus which is almost always fatal after the onset of symptoms. The objective of this study was to identify the characteristics of dog shelters associated with the probability that the shelter had a policy to vaccinate shelter personnel against rabies. Five states with an established shelter registry were selected from each geographic region of the United States. A list of shelters within those states was developed from the registry list, through Internet searches and comparisons with other known lists. At least two forms of direct communication were used to ensure that humane organizations met the study definition of a dog shelter. In total, 342 of 461 (73%) shelters that met the study definition were visited by a team of students. Forty-two of 332 (13%) shelters responding to the question required staff to be vaccinated against rabies. Logistic regression was utilized to test shelter characteristics for association with the probability that they have a rabies vaccination policy for shelter staff. Municipally funded shelters were more likely to vaccinate staff for rabies than shelters funded privately (OR = 3.0, 95% CI = 1.40-6.39). These results demonstrate that shelter funding source may influence rabies control programmes in shelters.

Sharp transection of the suspensory ligament as an alternative to digital strumming during canine ovariohysterectomy

OBJECTIVE

To compare time efficiency and nociceptive input between digital strumming (DS) and sharp transection (ST) of the suspensory ligament during ovariohysterectomy (OVH).

STUDY DESIGN

Randomized controlled trial.

ANIMALS

30 adult female dogs.

METHODS

Dogs were randomly assigned to ST or DS procedures. Measures of nociception were assessed through measurements of preoperative and intraoperative heart rate during manipulation of the suspensory ligament. Measures of pain were assessed through preoperative and postoperative pain scores by using the short form Glasgow Composite Pain Scale. Time efficiency was measured through total surgical time and the time to release each suspensory ligament.

RESULTS

After body weight was accounted for, the total surgical time was 1.1 minutes (P = .06) faster for ST than for DS, and each additional kilogram of body weight increased total surgical time by 0.1 minutes (P = .02). Digital strumming had 30.6-fold greater odds of taking greater than 1 minute compared with ST (P = .001). The heart rate from baseline to peak was 7.4 beats per minute lower in the ST group than in the DS group (P = .06). No complications were observed, and there was no difference in postoperative pain scores between treatments.

CONCLUSION

Sharp transection was faster and generated less intraoperative acceleration in heart rate but did not differ in postoperative outcomes compared with DS.

CLINICAL SIGNIFICANCE

Sharp transection is a viable alternative to DS for breakdown of the suspensory ligament during canine OVH. Sharp transection may improve surgical efficiency, especially when performing large volumes in the spay/neuter setting and could influence veterinary student training.

Clinically Prepared Veterinary Students: Enhancing Veterinary Student Hands-on Experiences and Supporting Hospital Caseload Using Shelter Medicine Program

Referral-level medicine is important in the veterinary curriculum, however veterinary students also need a solid base knowledge of clinically relevant, routine surgical and diagnostic skills to be clinically prepared after graduation. Exposure to a referral-only, or primarily referral caseload, does not always provide veterinary students with the routine hands-on experiences and competencies expected by the American Veterinary Medical Association Council on Education, the Royal College of Veterinary Surgeons, the Australian Veterinary Boards Council, or prospective employers. The aim of this descriptive study was to assess how a shelter medicine program can fill the companion animal caseload gap and create the necessary hands-on experiences considered essential in the veterinary curriculum. Pedagogical frameworks, course curriculum and design, student experiences, and student assessments were described for three core curricular areas (surgery, medical days, population medicine) of the Shelter Medicine Program at Mississippi State University. The shelter surgery experience provided a high-quality, high-volume spay/neuter environment where fourth-year students averaged 65 sterilization surgeries in two weeks and demonstrated a quantifiable decrease in surgical time. The shelter surgery experience added on average 9,000 small animal cases per year to the overall hospital caseload. Shelter medical days, where students provide veterinary care during on-site shelter visits, created opportunities for third-year students to directly interact with shelter animals by performing physical examinations and diagnostic testing, and to gain experience in developing treatment protocols and recommendations for commonly encountered problems. The shelter medical days experience averaged over 700 small animal cases per year and over 1,500 diagnostic procedures. Finally, students participated in 15 onsite shelter consultations where they obtained a working knowledge of biosecurity at a population level, including how to minimize the risk of infectious diseases spreading to healthy populations. Despite several challenges, results from this curricular program assessment support the aim that animal shelters and humane organizations offer opportunities that can be mutually beneficial for both animal organizations and veterinary students. The primary care caseload for the teaching institution was positively impacted, and students were better prepared to meet potential employers’ expectations and fulfill required core competencies in veterinary medical education.

Retroviral-mediated gene transfer of CSF-1 into op/op stromal cells to correct defective in vitro osteoclastogenesis

Colony-stimulating factor-1 (CSF-1) released by stromal cells in the bone microenvironment is essential for the proliferation of osteoclast progenitors. In op/op mutant mice, a thymidine insertion in the coding sequence of the CSF-1 gene results in CSF-1 deficiency that in turn leads to decreased osteoclast production and osteopetrosis. Because the osteopetrotic defect is due to the failure of stromal cells to produce CSF-1, we determined if retroviral-mediated gene transfer of the wild-type CSF-1 cDNA into op/op stromal cells would restore their ability to support osteoclast formation in vitro. A retroviral vector, L-CSF-1-SN, was constructed by inserting 1,867 bp of the wild-type CSF-1 cDNA into pLXSN. After transduction with L-CSF-1-SN or LXSN constructs, a stable PA31 7 packaging cell line that produced a high viral titre was isolated. Viral supernatant from this line was used to infect op/op bone marrow stromal cells. Stable L-CSF-1-SN op/op stromal clones overexpressed CSF-1 mRNA and released CSF-1 into conditioned medium, compared with no CSF-1 released by LXSN op/op stroma. The amount of CSF-1 produced by two clones was similar to the physiologic level released by normal littermate stroma. Southern blot analysis confirmed the presence of intact proviral sequences in transduced cells. In coculture assays, L-CSF-1-SN, but not LXSN, op/op stromal cells supported the formation of TRAP-positive multinucleated cells in the absence of exogenous CSF-1. These findings indicate that genetically engineered stromal cells may be used to improve defective osteoclastogenesis and suggest that targeting stromal cells to bone is a potentially useful therapeutic modality for treating bone disorders.

Inhibition of mesangial cell proliferation by platelet factor 4

Platelet factor 4(PF4), an abundant platelet secretory product, is a strong candidate for modulating glomerular pathology. Because PF4 might be released from platelets and influence intrinsic cell growth during glomerular injury, the effect of PF4 on fetal calf serum- and platelet-derived growth factor (PDGF)-induced mesangial cell mitogenesis was examined. Mitogenesis was measured as the amount of 3H-thymidine incorporated into acid-precipitable material as well as by autoradiography. The effect of PF4 on mesangial cell expression of mRNA for PDGF A chain and transforming growth factor-beta (TGF-beta 1) was also examined. Fetal calf serum (10%)- and PDGF (10 ng/mL)-stimulated increases in mesangial cell 3H-thymidine incorporation were inhibited by incremental concentrations of PF4 (1 to 25 micrograms/mL) showing a maximum reduction of approximately 80% at 25 micrograms/mL of PF4. PF4 was effective when added 24 h before and 1, 4, and 8 h, but not 16 h after the addition of PDGF, indicating that inhibition occurred at delayed events in cell-cycle regulation. PF4 inhibited PDGF-induced increments in mRNA encoding PDGF A chain and TGF-beta 1. Also, PF4 did not interfere with PDGF receptor binding. The results of this study show that PF4 is a negative regulator of mesangial cell proliferation and suggest an interference in cell growth by pathways associated with modulation of the autocrine growth factors PDGF and TGF-beta 1.

Characterization and regulation of the latent transforming growth factor-beta complex secreted by vascular pericytes

Transforming growth factor-beta (TGF-beta) stimulates the accumulation of extracellular matrix in renal and hepatic disease. Kidney glomerular mesangial cells (GMC) and liver fat-storing cells (FSC) produce latent of inactive TGF-beta. In this study, we characterized the latent TGF-beta complexes secreted by these cells. Human FSC produce a single latent TGF-beta complex, predominantly of the TGF-beta 1 isoform, whereas GMC secrete multiple complexes of latent TGF-beta, containing beta 1 and beta 2 isoforms. At least four forms were identified in GMC using ion exchange chromatography, including a peak not previously described in other cell types which eluted at 0.12 M NaCl, and predominantly of the beta 2 isoform. Both cell types secrete the latent TGF-beta 1 binding protein of 190 kDa, as part of a high molecular weight TGF-beta complex. Epidermal growth factor stimulates the secretion of latent TGF-beta and latent TGF-beta binding protein in both cell types. Secretion of latent TGF-beta in both cell types was found to be associated with secretion of decorin. This study shows that vascular pericytes from the kidney and the liver have distinctly different profiles of latent TGF-beta complexes, with GMC secreting a unique form of latent TGF-beta 2. The regulatory effect of epidermal growth factor and platelet-derived growth factor has potential implication for the pathophysiology of liver regeneration and chronic liver and kidney diseases.

Cell type-specific activity of the N-myc promoter in human neuroblastoma cells is mediated by a downstream silencer

The N-myc oncogene is actively transcribed in many neuroblastoma tumors, but is not expressed in mature, normal tissue of any type. Chloramphenicol acetyl transferase (CAT) assays of constructs containing N-myc sequence transfected into N-myc expressing LA-N-5 neuroblastoma cells or non-expressing HeLa carcinoma cells have revealed a 201 base pair (bp) regulatory region mediating the cell type-specific activity of the promoter. While located downstream from 5' mRNA cap sites, the region appears to function by preventing transcriptional initiation. This downstream region is capable of suppressing promoter activity independently of position, and contains an element having 100% homology with the 9 bp consensus sequence of a transcriptional silencer found in the upstream region of the lysozyme gene. DNA gel retardation assays have shown that this sequence is involved in a specific DNA-protein interaction with nuclear extract from HeLa cells that is distinct from that occurring with extract from LA-N-5 cells. These results suggest that the N-myc promoter's cell type-specific activity is regulated by a downstream silencer, and that differential binding of regulatory protein from that present in non-expressing cells may result in the constitutive N-myc expression seen in neuroblastoma.

In situ demonstration of mature oligodendrocytes and their processes: an immunocytochemical study with a new monoclonal antibody, rip

This paper introduces "Rip" a monoclonal antibody that produces relatively complete staining of oligodendrocytes and their processes in the adult central nervous system (CNS). The distribution of Rip immunoreactivity coincides with that of myelinated axons in both the spinal cord and the cerebellum. In addition, double-immunolabeling experiments demonstrate that Rip stains processes containing myelin basic protein but does not stain processes that express glial fibrillary acidic protein. These results indicate that Rip selectively stains oligodendrocytes but not astrocytes. Moreover, individual Rip-stained oligodendrologial somata and their cytoplasmic processes were observable at both the light microscopic and electron microscopic level when the staining of myelin was reduced. This was accomplished by omitting detergents from antibody incubation steps. Rip-stained oligodendrocytes have multiple processes of varying thickness, some of which end in close proximity to myelin sheaths. These immunostained profiles, reminiscent of those observed in oligodendrocytes stained by Golgi methods, are unique to Rip and indicate that its immunoreactivity is distinct from that of existing serological markers for oligodendrocytes.

Treatment of cancer with heavy charged particles

A clinical radiotherapeutic trial using heavy charged particles in the treatment of human cancers has accrued over 400 patients since 1975, 378 of whom were treated with particles and 28 with low LET photons as control patients. Heavy charged particle radiotherapy offers the potential advantages of improved dose localization and/or enhanced biologic effect, depending on particle selected for treatment. Target sites have included selected head and neck tumors, ocular melanomata, malignant gliomata of the brain, carcinoma of the esophagus, carcinoma of the stomach, carcinoma of the pancreas, selected juxtaspinal tumors and other locally advanced, unresectable tumors. A Phase III prospective clinical trial has been started in carcinoma of the pancreas using helium ions. Phase I-II studies are underway with heavier particles such as carbon, neon and argon ions in order to prepare for prospective Phase III trials. Silicon ions are also under consideration for clinical trial. These studies are supported by the United States Department of Energy and National Institutes of Health.