Management of feline distal tibial fractures using a hybrid external skeletal fixator.

OBJECTIVE: To document the results of management of feline distal tibial fractures with circular-linear hybrid external skeletal fixators. METHODS: Retrospective examination of case records and radiographs of cats with distal tibial fractures managed with hybrid external skeletal fixators. Signalment, pre-operative fracture conformation, post-operative fracture reduction, implant complications, time to tibial and fibular fracture healing and time to hybrid external skeletal fixators removal were analysed. RESULTS: Case records of eight cats were reviewed and included three closed fractures and five type 1 open fractures. Post-operative fracture reduction was considered appropriate in all cases. Healing of five tibial fractures was complete and hybrid external skeletal fixators were removed within a mean of 13 weeks. Healing of the fibular fracture was complete within a mean of 12 · 1 weeks. Three tibial fractures demonstrated non-union and were revised after a mean duration of 24 weeks. All three non-union fractures were open on presentation. CLINICAL SIGNIFICANCE: Feline distal tibial fractures may be managed with hybrid external skeletal fixators, however, non-union still occurs. In this study type I open feline distal tibial fractures appeared more likely to develop non-union.

Carpal canal lipoma causing lameness in a dog.

Carpal canal syndrome, or carpal tunnel syndrome, is the most common entrapment neuropathy in humans and is caused by compression of the median nerve as it courses through the carpal canal. A similar condition has been reported in horses, however there have not been any reported cases of a dog showing lameness secondary to compression within the carpal canal. This report describes the case of a dog exhibiting lameness secondary to a lipoma within the carpal canal. Lameness improved after surgical removal of the mass. This case highlights the need to consider compression of the tendons and nerves in the carpal canal as a cause of forelimb lameness in dogs when pain is localised to the carpus.

Propagation of a partial incomplete ossification of the humeral condyle in an American cocker spaniel.

A hypoattenuating lesion in the left humeral condyle of an American cocker spaniel consistent with partial incomplete ossification of the humeral condyle was observed on computed tomography. Left forelimb lameness developed over the following three weeks at which time repeat computed tomography examination confirmed propagation of the lesion. Lameness resolved following placement of a transcondylar positional screw, suggesting that lameness was secondary to condylar instability. To the authors' knowledge this is the first report of propagation of an intracondylar lesion in a dog.

Preliminary results of five feline total hip replacements.

Five feline total hip replacements (including one case of staged bilateral total hip replacement) for management of proximal femoral physeal fractures are reported. The surgical procedure was a modified version of that widely used in dogs. Craniodorsal luxation was the only major complication encountered. Subjectively outcomes appeared to be good in all cases.

Delayed spinal cord injury following microchip placement in a dog.

A three-year-old female, entire Yorkshire Terrier dog was examined because it had progressive non-weight-bearing left forelimb lameness and tetraparesis of two weeks duration. Clinical signs were first observed following mating. Examination confirmed non-weight-bearing left forelimb lameness and tetraparesis. Left forelimb muscle atrophy was also noticed. Survey radiography revealed a metallic foreign body consistent with a microchip in close proximity to the left articular facets between the fifth and sixth cervical vertebrae. Computed tomography identified the exact location of the foreign body encroaching on the left dorsolateral vertebral canal, and osteolysis of the lamina of the sixth cervical vertebra. Surgical removal of the foreign body was performed via a dorsal approach to the caudal cervical vertebral column. Two weeks following surgery the dog showed return of left forelimb function and resolving tetraparesis. Microchip implantation had been performed three years previously.

Small heat shock proteins (sHSPs) as potential drug targets.

Small heat shock proteins (sHSPs) belong to a family of 12- to 43-kDa proteins that are ubiquitous and are largely conserved in amino acid sequence among all organisms. The principal heat-shock proteins that have chaperone activity (that is, they protect newly made proteins from misfolding) belong to five conserved classes: HSP100, HSP90, HSP70, HSP60 and the small heat-shock proteins (sHSPs). The sHSPs (which include alpha crystallin) can form large multimeric structures and have a wide range of cellular functions, including endowing cells with thermotolerance in vivo and being able to act as molecular chaperones in vitro; sHSPs do this by forming stable complexes with folding -or unfolding--intermediates of their protein substrates, probably the molten globule. This paper includes: a brief survey of the chaperone family, the small heat shock protein superfamily, transcription of sHSPs, sequence comparisons and structural models of small heat shock proteins--structural elements as potential drug targets, sHSPs as chaperone-like proteins, alpha crystallin chaperone-like activity, conformational diseases--the role of alpha crystallin small heat shock protein superfamily proteins, post-translational modification and useful pharmacological agents. Functionality of small heat shock proteins--targets and diseases where pharmacologically active agents are of importance, alpha crystallin--small heat shock proteins and prion diseases: specific targets for diagnostic tests and drug development, details of some specific small heat shock proteins as drug targets, structural and functional implications for treatment.

Chaperone function of mutant versions of alpha A- and alpha B-crystallin prepared to pinpoint chaperone binding sites.

A major stress protein, alpha-crystallin, functions as a chaperone. Site-directed mutagenesis has been used to identify regions of the protein necessary for chaperone function. In this work we have taken some of the previously described mutants produced and assessed their chaperone function by both a traditional heat-induced aggregation method at elevated temperature and using enzyme methods at 37 degrees C. In general the different assays gave parallel results indicating that the same property is being measured. Discrepancies were explicable by the heat lability of some mutants. Most mutants had full chaperone function showing the robust nature of alpha-crystallin. A mutant corresponding to a minor component of rodent alpha A-crystallin, alpha Ains-crystallin, had decreased chaperone function. Decreased chaperone function was also found for human Ser139--> Arg, Thr144-->Arg, Ser59-->Ala mutants of alpha B-crystallin and double mutants Ser45-->Ala/Ser59-->Ala, Lys103--> Leu/His104-->Ile, and Glu110-->His/His111-->Glu. A mutant Phe27-->Arg that was the subject of previous controversy was shown to be fully active at physiological temperatures.

Management of cervical spondylopathy-associated intervertebral, disc protrusions using metal washers in 78 dogs.

Intervertebral 7.5 mm (n = 75) and 6.0 mm (n = 22) metal washers were used to distract intervertebral spaces in 78 consecutive cases of canine cervical spondylopathy-associated disc protrusions, where myelography had demonstrated traction-responsive spinal cord compression. Nineteen dogs had compressive lesions at two sites. Fifty lesions were evaluated myelographically on immediate postoperative radiographs; of these, 32 compressions had been eliminated and 18 had been reduced. Euthanasia was performed in nine dogs within six months of surgery and 15 dogs had varying degrees of neck pain during this period. Long-term follow-up information was available on 65 dogs nine to 70 months following surgery (median 32 months). Sixty-three of these dogs improved postoperatively. Neurological function subsequently deteriorated in 17 dogs 10 to 59 months following surgery (median 34 months). Eight of these 17 cases had further myelographic investigations and all had additional disc protrusions with no evidence of cord compression at the previous sites of surgery. The remaining nine cases had a deterioration in hindlimb function but were not investigated further.

Laminectomy for 34 dogs with thoracolumbar intervertebral disc disease and loss of deep pain perception.

The case details and the results of treatment of 34 dogs with thoracolumbar intervertebral disc disease, without deep pain perception, that had been treated by laminectomy and fenestration, are presented. The association of a number of potential prognostic factors with the neurological outcome is examined. Twenty-one dogs (62 per cent) recovered neurological function, seven (21 per cent) failed to recover neurological function and three (9 per cent) developed progressive myelomalacia postoperatively, while three dogs (9 per cent) were euthanized intraoperatively because of diffuse myelomalacia. Twenty of the dogs that recovered neurological function showed a return of deep pain perception within two weeks of decompressive surgery. Statistical analysis showed significant differences in the outcome between dogs that took less than one hour to lose the ability to ambulate and dogs with a longer duration of onset of inability to ambulate. The extent of spinal cord swelling determined by myelography was not found to be a useful prognostic indicator.

Maintenance of chaperone-like activity despite mutations in a conserved region of murine lens alphaB crystallin.

PURPOSE: To understand the relationship between certain conserved residues in alphaB crystallin and the chaperone-like function of the protein. METHODS: In alphaB crystallin, residues H101 to R120 are highly conserved between alphaB crystallin and alphaA crystallin (85% identity), and between alphaB crystallin and the small heat shock protein hsp 27 (80% identity). We made three substitution mutants of alphaB crystallin: the single mutant F118A, and the double mutants K103L/H104I, and E110H/H111E. RESULTS: Polyacrylamide gel electrophoresis revealed no decrease in aggregate size or measureable structural changes between them and the native structure. Using the insulin aggregation assay, all three mutants had identical chaperone-like activity to the wild-type recombinant alphaB crystallin. CONCLUSIONS: Despite the high conservation in this area of sequence between alphaB crystallin, alphaA crystallin, and the small heat shock protein hsp 27, mutations F118A, K103L/H104I, and E110H/H111E did not significantly alter chaperone-like activity.

Clinical experience over 48 years with pheochromocytoma.

OBJECTIVE: To analyze the presentation, localization, surgical management, pathology, and long-term outcome of a large series of patients with pheochromocytomas. SUMMARY BACKGROUND DATA: There are several areas of controversy pertaining to pheochromocytomas. Although many studies report a higher rate of malignancy for extraadrenal pheochromocytomas than for adrenal pheochromocytomas, the number of patients with the former tumor are small and statistical analysis is lacking. There has also been recent debate as to whether microscopic features of the tumor may be predictive of future behavior. METHODS: From 1950 to 1998, the authors observed 108 pheochromocytomas in 104 patients. The outcome of these patients has been followed prospectively. The medical records of these patients were reviewed for data on the presentation, localization, surgical management, pathology, and outcome. Patient survival was analyzed using Kaplan-Meier survival distributions. RESULTS: This study included 66 female patients and 38 male patients. The average age at surgery was 42.3 years. Sporadic cases accounted for 84% of the patients; the other 16% had multiple endocrine neoplasia type 2, von Recklinghausen's disease, von Hippel-Lindau disease, or Carney's syndrome. Of 64 adrenal tumors, 55 were initially considered benign, 6 had microscopic malignant features, and 3 had malignant disease. Mean patient follow-up was 12.6 years. To date, in five additional patients (none with microscopic disease) malignant disease developed (13% overall rate of malignancy). Recurrence occurred as late as 15 years after resection. Of 26 extraadrenal pheochromocytomas, 14 were initially considered benign, 8 had microscopic malignant features, and 4 had malignant disease. Thus, 46% of patients had either malignant disease or tumors with malignant features. Mean patient follow-up was 11.5 years. In one patient with benign disease and in one patient with malignant features, malignant disease developed (23% overall rate of malignancy). The difference in the rate of malignancy was not statistically significant between adrenal and extraadrenal pheochromocytomas. Patients with adrenal and extraadrenal pheochromocytomas also had similar rates of survival (p = NS). CONCLUSIONS: The data suggest that patients with extraadrenal pheochromocytomas have the same risk of malignancy and the same overall survival as patients with adrenal pheochromocytomas. Lifelong follow-up of these patients is mandatory.

Effect of mutations of murine lens alphaB crystallin on transfected neural cell viability and cellular translocation in response to stress.

We examined the influence of over-expressed native and mutant murine lens alphaB crystallin on the response of a murine neural cell line to heat and ionic strength shock. Native and mutant (F27R and KK174/175LL) murine alphaB crystallin amplicons were subcloned into a Lac-Switch IPTG-inducible RSV promoter eukaryotic vector, and transfected into N1E-115 cells using lipofectin. Expression was induced maximally 8 h after addition of IPTG (optimal final concentration 1 mM) to the medium. Cells grew normally after transfection with native and mutant murine alphaB crystallin. We demonstrated expression of the protein using specific anti-alpha crystallin antibodies. Viability under severe heat and ionic strength stress increased when cells had been transfected with native alphaB crystallin, but not with mutants F27R or KK174/175LL. Heat shock caused translocation of both native and mutant alphaB crystallins into the central region of the cells. These results show that mutations in alphaB crystallin that effect its chaperone-like activity may also influence viability of N1E-115 neural cells under stress, while not influencing the distribution of the protein within the cell.

Hemilaminectomy for the treatment of thoracolumbar disc disease in the dog: a follow-up study of 40 cases.

A study was made of dogs with Hansen type I thoracolumbar disc extrusions that had been treated by hemilaminectomy and fenestration of the affected disc. Follow-up information was available for 40 dogs undergoing treatment over a five-year period. The follow-up period ranged from 12 to 72 months (mean 34 months). The case details and the results of treatment of these 40 dogs are presented. All dogs were graded according to the degree of neurological dysfunction at the time of initial presentation and at the conclusion of the study period. Twenty-seven dogs (68 per cent) had no detectable signs of neurological dysfunction or thoracolumbar pain at the final assessment and a further eight dogs (20 per cent) had mild ambulatory paraparesis but were regarded by their owners as functional pets. Recurrence of neurological signs consistent with thoracolumbar disc disease was seen in five dogs (13 per cent) and was successfully resolved completely in one of three dogs that were treated.

Fibro-cartilaginous embolism in a cat.

A nine-year-old cat was presented with a history of an acute onset of paraplegia. On the basis of the neurological examination, the lesion was localised between the fourth lumbar and third sacral segments (L4 to S3) of the spinal cord. Investigations included radiography, myelography, cerebrospinal fluid analysis, routine haematology and biochemistry, feline leukaemia virus testing and urinalysis. A definitive diagnosis was not achieved and the cat was euthanased 12 days after presentation. Post mortem examination revealed infarction of the spinal cord secondary to fibrocartilaginous embolisation. This is the first reported case of fibrocartilaginous embolism in the cat in the UK.

Hypermagnesemia-induced paralytic ileus.

Hypermagnesemia is a well-known cause of hypotension and cardiac dysfunction but not well recognized is the induction of paralytic ileus. This report details the second and third adult patients reported with hypermagnesemia-induced paralytic ileus. The first patient was a 65-year-old white woman with normal renal function, who had consumed large amounts of magnesium citrate and milk of magnesia. As magnesium blood level fell from 5.1 mg/dl on admission to 2.4 mg/dl on day 3, the vomiting, obstipation, and abdominal distension resolved. The second patient was a 67-year-old woman with mild renal insufficiency, who consumed a large amount of Epsom salts containing magnesium sulfate to treat her constipation. Magnesium levels of 8.1 mg/dl on admission fell to below 3.1 mg/dl on the third hospital day and the paralytic ileus resolved. Mechanical obstruction was ruled out by colonoscopy, gastrographin enema, and barium small bowel series in both patients. Although the clinical findings of muscle weakness, flaccid paralysis, respiratory muscle paralysis or cardiac arrest due to hypermagnesemia are well described in the literature, intestinal smooth muscle dysfunction leading to paralytic ileus has only been reported in one other adult patient. The laboratory and clinical course of these two patients strongly suggest a causal relationship between hypermagnesemia and paralytic ileus.

Heterogeneity of personality traits in massive obesity and outcome prediction of bariatric surgery.

The search for heterogeneity of personality characteristics amongst the massively obese is extended to a larger sample (n = 215) of both males (n = 83) and females (n = 132). The Minnesota Multiphasic Personality Inventory standard scales serve as the data base for a cluster analysis which has yielded four clusters: cluster 1 (n = 36) where all scales fell well within normal limits; cluster 2 (n = 112) was coded as 3-1 and was also within normal limits; cluster 3 (n = 44) was coded as spike 4; and cluster 4 (n = 23) was coded as 2-1-7-3-8-4. Cluster membership was not related to surgeons' four-year follow-up overall outcome rating. Discriminant function analysis yielded two variables (patient age and MMPI scale 1 T-score) which were significant predictors of subsequent outcome. The results suggest that there is heterogeneity of personality traits among the massively obese and offer encouragement to the search for variables that are even more effective predictors of the outcome of bariatric surgery.

Jejunoileal bypass arthritis.

Although intestinal bypass procedures are no longer performed, important lessons have been learned concerning clinical arthritides resulting from bacterial overgrowth and immune complex deposition. This information is of considerable value in patients who present with the clinical picture of intestinal bypass arthritis on the basis of other bowel abnormalities. Furthermore, the pathogenetic mechanisms involving bacterial overgrowth, release of bacterial antigens, and immune complex deposition may be pertinent to many types of inflammatory arthritis.