The canine baculum: the structure and mechanical properties of an unusual bone.

The baculum is an extraskeletal bone located in the penis of a few species in several orders of mammals such as carnivores, insectivores, rodents, bats and primates. This study aims to describe the structure, architecture and mechanical properties of the canine baculum. To this end canine bacula from castrated and uncastrated dogs were collected and examined by light microscopy, micro-computed tomography (microCT) scanning, histological staining, and mechanical testing. Their mineral density and mechanical properties were compared with those of a typical skeletal bone (the radius) in the same dog. Furthermore, a numerical model of a representative baculum was created and its mechanical performance analyzed using the finite element method, in order to try to elucidate its function. Examination of light microscopy images of transverse sections shows that the baculum consists of a typical sandwich structure, with two cortical plates separated, and joined, by loose cancellous bone. MicroCT scans reveal that the mineral density is lower in the baculum than in the radius, both in castrated as well as in uncastrated dogs, resulting in much lower stiffness. Castration was found to decrease the mineral density in both the baculum and the radius. The most likely function of the baculum of the dog is to stiffen the penis to assist intromission, and its much lower mineral density compared to that of the radius may be a mechanism designed to decrease the stiffness somewhat, and thus reduce the risk of fracture during copulation.

Mycobacterium bovis BCG Danish Strain 1331 isolated from a periarticular lesion in a domestic cat.

A 7-year-old male neutered domestic shorthair outdoor cat was referred for chronic left forelimb lameness, which had been treated with intra-articular injections of triamcinolone acetonide. A soft tissue swelling around the elbow joint, extending from the distal humerus to the proximal ulna, was surgically explored and biopsy samples obtained. Mycobacterium bovis was cultured from samples from the soft tissue and bone. The mycobacteria from the media were killed and the DNA extracted and tested on a multiplex real-time PCR for the absence of specific genes and the presence of mycobacterial genus markers. The PCR revealed bacillus Calmette-Guérin Danish Strain 1331; this was also isolated from the prescapular lymph node, muscle and bone, obtained at post mortem examination. Badgers had been vaccinated with the bacillus Calmette-Guérin vaccine SSI (Statens Serum Institute) in the area where the cat lived, in the spring and autumn of the previous year. To the authors' knowledge, this is the first report of infection with M. bovis bacillus Calmette-Guérin Danish Strain 1331 in a domestic cat, potentially associated with annual vaccination of badgers in the proximity of the cat's home.

Biochemical identification of homogentisic acid pigment in an ochronotic egyptian mummy.

Roentgenograms of an Egyptian mummy, dating from 1500 B.C., showed extensive calcification of the intervertebral discs and articular narrowing in both hip and knee joints. Biopsy cores from the right hip showed parallel black zones in the region of the articular surfaces, leading to a clinical diagnosis of ochrinosis. The black pigment was extracted, analyzed, and compared to an air-oxidized homogentistic acid polymer. The two substances apparently were identical. The chemical evidence thus confirms the clinical finding of ochronosis, an autosomal recessive disorder. This is, so far as known, the earliest verified case of this disorder.

Initial investigation of mortality rates and prognostic indicators in horses with colic in Israel: a retrospective study.

REASONS FOR PERFORMING STUDY: Initial assessment of the mortality rates and prognostic indicators in horses with colic presented to a referral hospital in Israel. OBJECTIVES: To determine mortality rates and to identify potential prognostic indicators in horses undergoing treatment for colic. METHODS: The medical records of 208 colic cases were reviewed and mortality rates calculated including 95% confidence intervals. Mortality rates in surgical cases were calculated separately for strangulating and nonstrangulating lesions as well as for lesions of the large and small intestines. Potential prognostic indicators were identified and evaluated by Student's t test or chi2 test, where appropriate. Those found to be significant (P < 0.05) were evaluated in 2 logistic regression models; one including all horses with colic and one for surgical cases only. RESULTS: The overall mortality rate was 51/208 (25%); 5/72 (7%) in medically treated cases, 46/136 (34%) in surgical cases, 30/50 (60%) in strangulating lesions and 15/85 (18%) in nonstrangulating lesions, 17/27 (63%) in cases involving small intestinal lesions and 28/108 (26%) in cases with large intestinal lesions. Clinical parameters found to be significantly associated with death by univariate analysis were medical/surgical treatment, location of lesion, severity of lesion, mucous membrane colour (MM), capillary refill time (CRT) and heart rate. Using a multivariate logistic regression model, including all cases, medical/surgical treatment, CRT and MM were found to be prognostic indicators and when using the surgical cases alone, only CRT and lesion severity remained related to mortality. CONCLUSIONS: Mortality rates were similar or better than those previously reported in most cases, however, studies from the USA and the UK published better success rates for small intestinal surgeries. Cultural attitudes toward euthanasia may be associated with mortality rates. POTENTIAL RELEVANCE: These results assist clinicians in providing an immediate prognosis based on clinical findings at presentation and contribute to an international database that may aid future research in improving treatment of colic.

A proposed technique for one-step preputial reconstruction in the dog.

OBJECTIVE: To describe a reverse axial pattern flap based on the superficial branch of the dorsal penile artery and describe its use in preputial reconstruction. MATERIALS AND METHODS: Ten penises were harvested from canine cadavers; five were used to describe the dermatome supplied by the superficial branch of the dorsal artery of the penis and five to show perfusion of the skin flap. The superficial branch of the dorsal artery of the penis was identified fluoroscopically by injecting contrast material into the dorsal artery of the penis. This artery was then catheterised and injected with methylene blue to identify the perfused area. A skin flap was created by making a full thickness skin incision at the level of the fornix, along the circumference of the penis. The flap was developed by pulling the cut end toward the tip of the penis while undermining the skin. The flap was considered long enough when the cut end of the flap reached the level of the urethral opening. We also describe a case of preputial resection and reconstruction using this flap. RESULTS: Injection of methylene blue demonstrated the arterial supply to the skin flap. This flap was successful in treating the clinical case following resection of a mast cell tumour on the prepuce, although a small area of full thickness flap necrosis, which healed by second intention, developed postoperatively. CLINICAL IMPORTANCE: This technique may be useful for single step preputial reconstruction.

Surgical management of sand colic impactions in horses: a retrospective study of 41 cases.

OBJECTIVE: A retrospective review of the medical records of 41 horses requiring abdominal surgery for sand colic. RESULTS: The diagnosis of sand colic was made when sand was found to be the cause of impaction of the gastrointestinal tract during surgical exploration. The most common clinical signs at presentation were abdominal pain, abdominal distension and diarrhoea. A statistically significant association was found between the respiratory rate on arrival and short-term survival. Sand impaction at multiple locations was detected in one-third of the horses. Concurrent pathology was detected in half of the horses. Four horses were euthanased during surgery; of those that recovered from surgery, 35/37 (95%) were discharged from hospital. Short- and long-term complications were similar to those previously reported. Long-term (1 year) survival of the horses discharged was 100%. CONCLUSION: The good prognosis for horses undergoing surgery for the treatment of sand impaction supports early surgical intervention in cases where large amounts of sand are suspected.

Successful management of bilateral patellar tendon rupture in a dog.

A seven-year-old, 41 kg, intact, cross breed dog, was presented with a history of bilateral hind limb lameness after falling from a height of 1 m. Clinical and radiographic findings were consistent with bilateral patellar tendon rupture. Surgical repair was performed bilaterally. The tendons were sutured primarily, and an internal splint of nylon leader was added. Good apposition of the severed tendon ends had been achieved intraoperatively; however, post operative radiographs showed supra-trochlear displacement of both patellae. The casts used to immobilize the stifle joints slipped distally and three days post operatively the tendon repair had broken down, bilaterally. Revision surgery was undertaken and the tendons were re-sutured. Nylon leader was placed through holes that had been drilled in the patellae and tibiae. The stifle joints were immobilized with type I external skeletal fixators (ESFs). Both freeform polymethylmethacrylate (PMMA) connecting bars were found to be broken at the level of the stifle joints two days later, without any disruption of the primary tendon repair. Each connecting bar was replaced with two connecting bars of PMMA reinforced with 3 mm steel wire. The dog was fully weight-bearing with a reduced range of motion in flexion immediately after removal of the ESFs at six weeks and was still sound 18 months post-operatively. Primary tendon repair in combination with adequate immobilization allowed for an excellent outcome in a complicated bilateral pathology.

Bacterial infective arthritis of the coxofemoral joint in dogs with hip dysplasia.

The objective of this study was to describe seven cases of unilateral bacterial infective coxarthritis from a total of 19 cases of bacterial infective arthritis (BIA), presenting over a two year period. We recorded the history, clinical signs, diagnostic process, treatment and clinical outcome in these cases. The data were obtained from medical records, review of the radiographs, and telephone follow-up with the owners. All of the dogs in this study had severe chronic osteoarthritis secondary to hip dysplasia, which caused periodic hind limb lameness. They were all admitted with severe acute hind-limb lameness. Pelvic radiographs were performed under general anaesthesia shortly after presentation, followed immediately by arthrocentesis of the affected joint. The synovial fluid was evaluated microscopically by direct smear and a sample was sent for culture and sensitivity. An attempt was not made to drain or lavage the affected joint during the course of treatment. The initial choice of antibiotics was empiric and subsequently modified, as required, based on the sensitivity results. Four of the dogs showed a rapid return to weight-bearing after the initiation of antibiotic treatment, and all of the patients returned to their pre-BIA level of function. Neither recurrent infections nor any adverse sequela requiring further intervention were reported by the owners on telephone follow-up.

Optically pumped Si nanocrystal emitter integrated with low loss silicon nitride waveguides.

We describe the integration of optically pumped silicon nanocrystals (Si-ncs) embedded in SiO(2) with low loss silicon nitride slab waveguides. An emission waveguide containing Si-ncs with a broad band emission centered at 850 nm, together with a low loss transmission silicon nitride waveguide forms a two section device. The waveguides are fabricated via the deposition of SiO(x) and silicon nitride using ECR-PECVD. Incorporation of hydrogen through annealing, while beneficial to emission from the Si-ncs, is found to increase material absorption in silicon nitride. This is reconciled by annealing at low temperature. This work shows clearly the potential for this material system as a means for the integration of optical emission and waveguiding using a wholly VLSI compatible processing technology. We further suggest that immediate applications exist in particular in the field of evanescent sensing.

Observations on Levitt's "new theory of transport".

Levitt (1974) (Biochim. Biophys. Acta 373, 115--131) has recently developed a "New Theory of Transport for Cell Membrane Pores" based on the supposition that equivalent pores in the red cell membrane are so small that water and small solute molecules such as urea can not pass each other. Levitt's concept is based on the implicit assumption that urea and water are spherical molecules. We have shown, using a scale model, that Levitt's supposition is not in agreement with the actual molecular shapes. Levitt has further asserted that there is a serious methodological error in measurements reported fifteen years ago by Goldstein and Solomon (1960) (J. Gen. Physiol. 44, 1--17). We have shown that the supposed "methodological error" lies in the fact that Levitt made his mathematical analysis of the appropriate equations under conditions significantly different from those employed by Goldstein and Solomon. A computer solution of the equations under the actual conditions used shows that Levitt's assertion is not justified.

Nonelectrolyte diffusion across lipid bilayer systems.

The permeability coefficients of a homologous series of amides from formamide through valeramide have been measured in spherical bilayers prepared by the method described by Jung. They do not depend directly on the water:ether partition coefficient which increases regularly with chain length. Instead there is a minimum at acetamide. This has been ascribed to the effect of steric hindrance on diffusion within the bilayer which increases with solute molar volume. This factor is of the same magnitude, though opposite in sign to the effect of lipid solubility, thus accounting for the minimum. The resistance to passage across the interface has been compared to the resistance to diffusion within the membrane. As the solute chain length increases the interface becomes more important, until for valeramide it comprises about 90% of the total resistance. Interface resistance is also important in urea permeation, causing urea to permeate much more slowly than an amide of comparable size, after allowance is made for the difference in the water:ether partition coefficient. Amide permeation coefficients have been compared with relative liposome permeation data measured by the rate of liposome swelling. The ratios of the two measures of permeation vary between 3 and 16 for the homologous amides. The apparent enthalpy of liposome permeation has been measured and found to be in the neighborhood of 12 kcal mol-1 essentially independent of chain length. Comparison of the bilayer permeability coefficients with those of red cells shows that red cell permeation by the lipophilic solutes resembles that of the bilayers, whereas permeation by the hydrophilic solutes differs significantly.

Aminopeptidase N gene expression and abundance in caprine mammary gland is influenced by circulating plasma peptide.

This study examined the localization and the effect of circulating peptides on the expression of aminopeptidase N (EC 3.4.11.2) in caprine mammary gland. Four lactating goats in mid to late lactation were used in a crossover design and were subjected to 2 dietary treatments. Abomasal infusion of casein hydrolysate was used to increase the concentration of peptide-bound amino acid in the circulation. Samples of mammary gland tissue from each goat were taken by biopsy at the end of each treatment period to measure gene and protein expression of aminopeptidase N in the tissue. There were no measurable effects on feed intake and milk production for any of the treatments. Western blot analysis showed that aminopeptidase N is located on the basolateral side of parenchymal cells and not on the apical membranes. Abomasal infusion of casein hydrolysate caused a marked change in the profile of arterial blood free amino acids and peptide-bound amino acids smaller than 1500 Da. Abundance of aminopeptidase N mRNA and protein increased by 51 and 58%, respectively, in casein hydrolysate-infused goats compared with the control treatment. It was concluded that aminopeptidase N is one candidate actively involved in the mammary gland to support protein synthesis and milk production. In accordance with the nutritional conditions in the current experiment, it is suggested that aminopeptidase N expression is partly controlled by the metabolic requirements of the gland and postabsorptive forms of amino acids in the circulation.

Long-term outcome of transendoscopic oesophageal mass ablation in dogs with Spirocerca lupi-associated oesophageal sarcoma.

Oesophageal sarcoma is a potential sequel of Spirocerca lupi infection. Oesophageal mass excision can be performed by open chest surgery. The objectives of this observational study were to evaluate the feasibility, short-term morbidity and long-term outcome of transendoscopic oesophageal mass ablation in dogs with spirocercosis-associated oesophageal neoplasia. A 9 mm video-endoscope and laser or electrocauterisation were used to debulk the oesophageal mass. Long-term follow-up was done by telephonic interviews. Fifteen dogs were included. The median tumour size was 5 cm (range 3.5-9). The median procedure time was 75 minutes (range 35-165) and was deemed successful in 12/15 dogs (80 per cent). Recovery was uneventful in all dogs. Immediate complications included oesophageal damage (two dogs) oesophageal perforation (one dog) and a focal thermal damage (one dog). The median hospitalisation time of all dogs was less than one day, with all but two discharged on the procedure day. The median survival time, available in nine dogs that were followed, was 202 days (range 51-691). Four of these dogs (44 per cent) survived more than six months, of which three survived more than one year. In conclusion, transendoscopic oesophageal mass ablation might be considered an alternative, palliative procedure for open-chest oesophageal surgery. It has comparable long-term survival, lower morbidity, short hospitalisation time and relatively low cost.

Minimally invasive unilateral arytenoid lateralization in dogs: A cadaveric study.

The aim of this study was to develop a minimally invasive thyroarytenoid lateralization technique (MITAL). Eleven unilateral MITAL procedures were performed on 11 canine cadavers. Two hypodermic needles were passed through the skin into the lumen of the larynx, penetrating the thyroid and arytenoid cartilages. Suture material was passed through the needles to lateralize the arytenoid cartilage. A rigid endoscope was used to visualize needle insertion and suture material placement. A key-hole approach to the larynx was performed and the suture material was knotted on the lateral aspect of the thyroid cartilage. The change in the rima glottidis area was recorded as were the duration of the procedure and complications encountered. The landmarks for needle insertion were easily palpated, and a significant increase in the area of the rima glottidis was documented after performing unilateral MITAL. In conclusion, unilateral MITAL is a quick, minimally invasive procedure which increases the area of the rima glottidis in cadaveric dogs.

Hemophilic bleeding evaluated by blood pool scanning.

The technique of blood pool scanning was used to examine 15 hemophilic subjects. Employing an in vivo method for erythrocyte labeling with Technetium-99 m, a dynamic perfusion sequence is obtained using a scintillation camera positioned over the area to be examined. This demonstrates the vascularity of the tissue. Subsequently, equilibrium blood pool images of the area are obtained and analyzed with a densitometer to assess relative regional blood volume. In patients who were not bleeding but had chronic arthropathy, vascularity was not increased, and the blood volume of comparable joints was similar. By contrast, marked increases in vascularity and image density were observed in studies of acutely bleeding joints. Chronic hemarthroses were associated with persistent, but less marked increases in joint perfusion. Transient increases in joint vascularity were demonstrated after insertion of knee prostheses. In a patient with a thigh hematoma, the dimensions of the hemorrhage were clearly delineated. Since only a tracer dose of nuclide is infused intravenously, there are no allergic reactions or other side effects of the procedure. Blood pool scanning is a safe, non-invasive technique that augments clinical and radiographic evaluations, and provides a new dimension in the assessment of the hemophilic patient.

Synovial osteochondromatosis: a histopathological study of thirty cases.

In thirty cases of synovial osteochondromatosis studied clinically and pathologically, the process appeared to follow a temporal sequence characterized by three recognizable phases (1) active intrasynovial disease only, with no loose bodies; (2) transitional lesions with both active intrasynovial proliferation and free loose bodies; and (3) multiple free osteochondral bodies with no demonstrable intrasynovial disease. If gross examination at the time of surgery shows that the disease is in the third phase, it would appear that synovectomy may not be necessary. However, extrasynovial intra-articular cartilaginous lesions may persist after synovectomy in the other two phases and may grow, causing recurrence of clinical symptoms in the absence of new intrasynovial disease.

Osteopetrosis. A morphological study of twenty-one cases.

Twenty-one patients, two months to seventy-eight years old, with clinically diagnosed osteopetrosis showed radiographic and histological variations in the formation of radiodense skeletal tissue at all ages. Pathologically the abnormal tissue was composed of both lamellar bone and calcified cartilage. We deduced that the abnormality or abnormalities of osteoclast function that cause the observed changes vary in severity from time to time in individual patients. Periods of remission in the less severely affected patients apparently had permitted the formation of bone-marrow spaces and allowed hematopoietic tissue to form in these patients. The patients who died of the disease did so because of anemia or its resulting complications. Some children with a lethal form of the disease had rickets and epiphyseal fractures in addition to the osteopetrosis. Focal areas of osteomalacia were observed in two specimens from adults. Traumatic and stress fractures were frequent complications at all ages.

Osteoarthritic changes at the severely degenerative disc in humans.

A series of postmortem spine specimens demonstrated new osteophytic cartilage production at levels of severe disc degeneration. This tissue is related to the cartilage found within the intervertebral disc. The sequence of pathologic changes occurring within these discs is shown radiographically and histopathologically. A cleft occurred between adjacent vertebral bodies, and recognizable disc material was absent at the cleft. The adjacent bone showed sclerosis, even extending deep within the bodies. Cartilage changes near the two end-plates resemble the histology of degenerative arthritis of hyaline cartilage of a synovial joint.

Unusual arthroscopic knee lesions: case report of an intra-articular lipoma.

Intra-articular lipoma is a rare benign tumor that should be considered in the differential diagnosis of a smooth lobular synovial mass. This article reports a patient who presented with right knee pain, locking, and swelling. At surgery, an intra-articular lipoma was found.