Omentalisation in the treatment of sublumbar abscessation: long-term outcome in 10 dogs.

The objectives of this study were to report the technique of omentalisation for the management of sublumbar abscessation associated with suspected migrating plant material, the intraoperative and postoperative complications that occurred and the long-term outcome of the cases. A retrospective case series of dogs (n=10) with sublumbar abscessation managed by exploration and drainage combined with omentalisation of the abscess cavity is reported in this study. The sublumbar area was approached through a ventral midline coeliotomy, the abscess was explored, drained, debrided and subsequently packed with omentum. One dog sustained an aortic rupture during exploration of the abscess, the aorta was repaired; there were no postoperative complications. There was long-term (>12 months) resolution of clinical signs in all dogs. Drainage and omentalisation of sublumbar abscesses resulted in complete resolution of signs in all dogs and was associated with a low incidence of complications. Omentalisation is an effective treatment for dogs presenting with sublumbar abscesses associated with suspected migrating plant material.

Diagnostic value of MRI in dogs with inflammatory nasal disease.

OBJECTIVES: To determine the value of low-field magnetic resonance imaging in differentiating sino-nasal aspergillosis from lymphoplasmacytic rhinitis in dogs. METHODS: A retrospective study of 41 dogs (25 with lymphoplasmacytic rhinitis and 16 with sino-nasal aspergillosis) that underwent magnetic resonance imaging scan of the nasal cavity was conducted. On magnetic resonance imaging, turbinate destruction was classified as mild, moderate or severe. The cribriform plate and vomer destruction were classified as present or absent. The intensity of fluid accumulation and turbinates was classified on T1-weighted and T2-weighted images as hypointense, hyperintense and isointense based on the brightest area on the same slice. RESULTS: Turbinate destruction was significantly (P=0·005) associated with sino-nasal aspergillosis. On T1-weighted images, sino-nasal aspergillosis was associated with turbinate hyperintensity, while lymphoplasmacytic rhinitis was significantly (P=0·007) associated with hypointensity. On T2-weighted images, this feature was shown not to be relevant. CLINICAL SIGNIFICANCE: This study has demonstrated that turbinate destruction is the most reliable feature to differentiate sino-nasal aspergillosis from lymphoplasmacytic rhinitis and that T1-weighted image was the most useful sequence.

Mediastinectomy for management of chronic pyogranulomatous pleural disease in dogs.

The medical records of 12 dogs with chronic pyogranulomatous pleural disease unresponsive to medical management were reviewed retrospectively. Resection of the mediastinal pleura (mediastinectomy) was performed through a median sternotomy to remove all diseased and surgically accessible mediastinal pleural tissue. Dogs were re-examined two weeks postoperatively, and long-term outcome was evaluated by contacting owners by phone. Twelve dogs underwent mediastinectomy; additional surgeries included subtotal pericardiectomy (8), lung lobectomy (4) and partial diaphragmatic resection (2). Histology of resected tissue consistently revealed neutrophilic, pyogranulomatous cellulitis/serositis. Foreign material was evident in the mediastinal tissue of five dogs and microorganisms were recovered from three dogs. Two dogs developed pneumothorax immediately postoperatively; one dog developed haemothorax one month postoperatively and was euthanased. Median follow-up time was eight months (range: 6-43 months); eleven dogs were alive and considered to be symptom-free by their owners. Mediastinectomy resulted in complete resolution of symptoms in most dogs (92 per cent) and was associated with a low incidence of major complications. The results of this study indicated that mediastinectomy results in favourable outcome for dogs with chronic pleural pyogranulomatous pleural disease unresponsive to medical management.

STIR muscle hyperintensity in the cervical muscles associated with inflammatory spinal cord disease of unknown origin.

OBJECTIVES: To assess the relation of a distinctive pattern of short tau inversion recovery muscle hyperintensity with inflammatory cerebrospinal fluid result in dogs. METHODS: All dogs that had a short tau inversion recovery sequence performed in addition to other magnetic resonance sequences of the cervical spine and concurrent cerebrospinal fluid evaluation during the study period were included. All magnetic resonance studies were anonymised and reviewed by a board certified radiologist and board certified neurologist. A board certified pathologist examined the cerebrospinal fluid and the results were reviewed. RESULTS: Forty-nine cases fulfilled the inclusion criteria. Repeatable patterns of short tau inversion recovery hyperintensity were identified in 20 dogs. The clinical diagnosis in all these 20 cases was of meningoencephalomyelitis of unknown origin. This diagnosis was confirmed by inflammatory cerebrospinal fluid changes in 18 and suspected from clinical presentation and response to therapy in the remaining 2. CLINICAL SIGNIFICANCE: In this study, the short tau inversion recovery changes identified were restricted to cases with inflammatory spinal cord disease. The short tau inversion recovery change had a sensitivity of 78%, and a specificity of 92% in predicting inflammatory cerebrospinal fluid, suggesting that short tau inversion recovery sequences are a useful addition to the investigation of suspected inflammatory spinal cord disease.

Prognostic significance of specific magnetic resonance imaging features in canine nasal tumours treated by radiotherapy.

OBJECTIVES: To investigate the prognostic significance of the magnetic resonance (MR) findings of meningeal hyperintensity of the olfactory bulbs and tumour extension into the caudal nasal recess (CNR) in dogs with nasal tumours treated by radiotherapy. METHODS: MR images of 41 dogs with nasal tumours treated with radiotherapy were reviewed. The occurrence of neurological signs and survival of patients with and without meningeal hyperintensity of the olfactory bulbs and tumour extension into the CNR were analysed together with possible confounding factors including intracranial extension and patient age. RESULTS: There was no significant association between the presence of meningeal hyperintensity or CNR involvement and the occurrence of neurological signs. Although there was a tendency towards shorter survival in dogs with tumour extension into the CNR, multivariable analysis showed no significant difference in survival between dogs with/without CNR involvement, meningeal hyperintensity or intracranial tumour extension (P=0.12, 0.50 and 0.57, respectively). CLINICAL SIGNIFICANCE: In dogs with nasal tumours treated with radiotherapy, tumour extension into the cranium is not necessarily associated with shorter survival in patients without neurological signs at time of diagnosis. Although a definite influence of CNR involvement on case outcome could not be demonstrated, studies with a larger population are warranted.

What is the significance of vortex vein invasion in uveal melanoma?

PURPOSE: To correlate vortex vein invasion with established prognostic factors for uveal melanoma. METHODS: Enucleated eyes with a confirmed histopathological diagnosis of uveal melanoma with vortex vein invasion were identified, over a 10-year period. Established uveal melanoma prognostic factors, with tumour genetics were correlated with vortex vein invasion and patient survival. RESULTS: Microscopic vortex vein involvement was present in 29 of 244 (11.9%) uveal melanomas. Of 29, 6 (20.7%) tumours had macroscopic evidence of vortex vein invasion. Of 29, 14 (48.3%) tumours also showed evidence of non-vortex vein, 'direct' scleral invasion. 23 (79.3%) of 29 melanomas involved only the choroid. The mean maximum diameter of tumours with vortex vein invasion was 15.8 mm and the mean thickness was 9.7 mm. The uveal melanoma was a discrete nodule in 27 of 29 (93.1%) cases. Histologically, 8 of 29 tumours (27.6%) were spindle cell, 19 of 29 (65.5%) were mixed cell, and 2 of 29 (6.9%) were epithelioid cell type. Of 29, 22 (75.9%) uveal melanomas with vortex vein invasion contained extracellular matrix networks and loops. Genetic abnormalities correlated with poor prognosis were seen in 25 of 29 (86.2%) tumours with vortex vein invasion. Liver metastasis was confirmed in 19 of 29 (65.5%) patients with vortex vein invasion. No patients with uveal melanomas showing vortex vein invasion suffered orbital recurrence of disease following enucleation. CONCLUSIONS: The trends show that vortex vein invasion is associated with a choroidal location, large tumour size, spindle cell bias, presence of extracellular matrix loops/networks and genetic markers. A higher proportion of patients with vortex vein invasion progress to develop liver metastasis compared with the general uveal melanoma population.

The development of a self-report measure to assess the location and intensity of pain in people with intellectual disabilities.

The performance of a target group of 20 people with intellectual disability (ID) and a comparison group of 20 people who did not have ID was investigated on a series of tasks involving the judgement of the location of pain (on a bodymap) and the intensity of pain (on an analogue colour scale) in response to a series of photographs of simulated painful experiences. The results of the study indicated that: (1) there were no differences between the target and comparison groups in judging pain location for 93% of test items; (2) the performance of the target group in judging pain location was stable over time; (3) people with ID rated the pain images as more intense than the comparison group on all the 'mild' pain stimuli and 36% of the 'severe' pain stimuli; (4) the performance of the target group in judging pain intensity was logically consistent for 65% of comparisons (clear trends towards significance being apparent for a further 10% of items); (5) the performance of the target group in judging pain intensity was stable over time; and (6) the performance of the target group was unrelated to indicators of cognitive ability.

Counselling implications of chromosomal abnormalities other than trisomy 21 detected through a maternal serum screening programme.

OBJECTIVE: To identify counselling requirements, we reviewed the frequency and type of non-trisomy 21 chromosome abnormalities found at amniocentesis after maternal serum screening for Down's syndrome. DESIGN: The study involved a review of the cytogenetic results of amniocenteses performed because of a raised maternal serum screening risk. SETTING: The maternal serum screening and amniocenteses were performed at hospitals in the Yorkshire region. SAMPLE: 1715 amniocenteses were performed as a result of a raised maternal serum screening risk for the period 1990 to 1993. METHODS: The cytogenetic results were classified into the main categories of numerical and structural chromosomal abnormalities. MAIN OUTCOME MEASURES: The nature and frequency of abnormal cytogenetic results were identified in which parental samples were required in order to determine if the abnormal finding was de novo or familial and/or for which specialist genetic counselling was required. RESULTS: Sixty-nine pregnancies of 1715 amniocenteses were identified with a chromosomal abnormality (4.0%): 35 (2.0%) with trisomy 21 and 34 (2.0%) with another chromosomal abnormality. For 20 of these 34 abnormalities, parental karyotypes were required and in 29 of the 34 specialist genetic counselling was required. CONCLUSIONS: Women undergoing maternal serum screening and, in particular, those proceeding to amniocentesis, should be informed that there is an equal chance that a chromosomal abnormality other than trisomy 21 will be found at amniocentesis, the nature of which usually requires parental samples and specialist counselling.

Is there an increased prevalence of severe learning disabilities among British Asians?

Age-specific prevalence rates for learning disabilities among the Asian communities in three Metropolitan Boroughs in the North of England are presented. These data indicate that: (1) below school age there is little difference in the apparent prevalence of severe learning disabilities between the Asian and non-Asian communities; (2) between 5 and 34 years of age, however, the apparent prevalence of severe learning disabilities is approximately three times higher among the Asian community when compared with the non-Asian community.

An unusual tricentric X chromosome detected prenatally.

We describe a female fetus with a de novo X chromosome rearrangement detected prenatally in both chorion villi and a pleural effusion. Chromosome painting showed the chromosome to be composed entirely of X chromosome material, while G-banding indicated a duplication of X short arms, four copies of the proximal long arm, and deletion of the distal long arm of the X. C-banding showed the presence of one active and two inactive centromeres and X-inactivation studies demonstrated the tricentric chromosome to be late replicating in all cells examined. The origin of this complex de novo rearrangement appears to have involved two separate breakage events, the first leading to the production of a dicentric X chromosome and the second generating the tricentric X.

Two 46,XX,t(X;Y) females with linear skin defects and congenital microphthalmia: a new syndrome at Xp22.3.

We describe two females with de novo X;Y translocations, who presented at birth with irregular linear areas of erythematous skin hypoplasia involving the head and neck, along with eye findings that included microphthalmia, corneal opacities, and orbital cysts. The features in these children are similar to but distinct from those seen in females with Goltz syndrome and incontinentia pigmenti. Cytogenetic analysis has shown the X chromosome breakpoint in both females to be at Xp22.3. We suggest that this syndrome is the result of a deletion or disruption of DNA sequences in the region of Xp22.3.

Duplication of distal 17q from a maternal translocation: an additional case with some unique features.

A female with multiple dysmorphic features was found to have an unbalanced karyotype with duplication of the distal long arm of chromosome 17 and deletion of the terminal region of the short arm of chromosome 12. This was derived from a reciprocal translocation in the mother, 46,XX,t(12;17)(p13.3;q23). Clinical findings are presented and comparison with other reported cases of distal 17q duplication shows several unique features in our case.

Calcium-independent stimulation of glycogenolysis by arginine vasotocin and catecholamines in liver of the axolotl (Ambystoma mexicanum) in vitro.

Arginine vasotocin (AVT) caused a concentration-dependent increase of glycogen phosphorylase alpha activity, breakdown of glycogen and release of glucose, when added to pieces of axolotl liver in organ culture. The concentration causing half-maximal response (EC50) was about 1 nmol/l. These actions of AVT were unaffected by the adrenergic antagonists propranolol, yohimbine and prazosin, but were blocked by equimolar amounts of d(CH2)5Tyr(Me)AVT, a synthetic antagonist of vasopressin. Arginine vasotocin similarly caused glycogenolysis in isolated perfused axolotl liver where the EC50 was about 0.1 nmol/l. The glycogenolytic action of AVT (10 nmol/l) was sustained for at least 3 h in Ca2+-free perfusion and longer in organ culture. No increase in Ca2+ concentration in the effluent perfusion medium was apparent during AVT-induced glucose release. Omission of Ca2+ from the medium, together with addition of EGTA (2.5 mmol/l) to the organ culture, had only a slight inhibitory effect upon the rate of glycogenolysis brought about by AVT and did not inhibit the glycogenolytic action of catecholamines. Addition of the calcium ionophore A23187 (5 mumol/l) neither caused glucose release nor abolished the glycogenolytic action of AVT added subsequently. Nevertheless, A23187 caused increased loss of 45Ca from Ca2+-loaded liver pieces whereas AVT was without effect. There was a slight accumulation of cyclic AMP (cAMP), but not cGMP, in axolotl liver pieces cultured in the presence of 0.1 mumol AVT/l and this was accentuated in the presence of phosphodiesterase inhibitors. We conclude that, in contrast to the position in mammals, Ca2+ is not involved in the glycogenolytic actions of AVT or catecholamines in axolotl liver. Preliminary experiments suggest that the same is true in the carp and we suggest that the involvement of Ca2+ in regulation of hepatic glucose release may not have evolved until after the amphibians separated from the ancestors of the mammals.

The effects and interactions of angiotensin and vasopressin on the heart of unanaesthetized sheep.

The effects of infusions of angiotensin and vasopressin, in stepwise concentrations, on the cardiac baroreflex and on cardiac output were studied in seven adult unanaesthetized sheep and compared with those obtained with infusions of phenylephrine. Six animals were treated with the beta-adrenoceptor blocking drug, propranolol (in order to inhibit the effects of the sympathetic nervous system on the heart). One animal was not treated with propranolol. In those animals in which arterial pressure increased during infusion of vasopressin, the slope of the systolic pressure-pulse interval relation was greater than that seen when phenylephrine was used to increase arterial pressure. Compared with the cardiac response to pressor doses of phenylephrine, infusions of angiotensin were associated with a lesser degree of cardiac slowing and a lesser reduction in cardiac output. The effects of combined infusions of angiotensin and vasopressin on the cardiac baroreflex were studied. In five sheep which were infused with a pressor dose of angiotensin (1.1 microgram/min), the stimulatory effect of vasopressin (1.0 u./min) on pulse interval and its depressant effect on cardiac output were attenuated. In seven sheep infused with 0.5 u./min of vasopressin, I.V. infusion of angiotensin (0.2-5.0 micrograms), produced a progressive decrease in pulse interval and increase in cardiac output as the dose was increased. Therefore, angiotensin can offset the cardioinhibitory effects of vasopressin. Since cardiac sympathetic activity was blocked and neither drug has any direct chronotropic effect on the heart, it would appear that these interactions between the two drugs affect the cardiac vagus either at a peripheral or central level.

Potentiation of cardiac vagal action by cold.

The effect of cold on vagal action at the heart was studied in sheep, dogs and an isolated guinea pig atrial preparation. During cardiac output measurements in unanaesthetized sheep, by the thermodilution method, bradycardia was evoked on injection of cold indicator in eight of 12 sheep studied. This bradycardia was consistently evoked when blood pressure was increased, but not at normal blood pressure levels. In the guinea pig atrial preparation, which has one vagus nerve attached, bradycardia was evoked by electrical stimulation of the vagus nerve. When the preparation was cooled this bradycardia was potentiated. In anaesthetized dogs, the cut peripheral end of one vagus was stimulated electrically at different frequencies. The linear relationship between pulse interval and vagal frequency was then compared at deep body temperatures of 35, 37, 39 and 41 degrees C. This comparison showed that the vagus prolonged pulse interval more effectively when the animal was cool (35 degrees C) than when it was warm (41 degrees C).

Genetic evidence that a Y-linked gene in man is homologous to a gene on the X chromosome.

The mammalian sex chromosomes are thought to be related to each other by sharing a common origin. That is, the X and Y chromosomes originally evolved from a pair of chromosomes that only differed at the locus determining sexual differentiation. For example, this evolutionary relationship is reflected during meiosis in chromosomal pairing between the tip of the human X chromosome short arm and the Y chromosome which presumably implies sequence homology. However, compelling genetic evidence for functional homology between the mammalian X and Y chromosome is lacking. We describe here the localization of a gene to the tip of the short arm of the human X chromosome and evidence for a related gene on the Y chromosome.

Hormonal control of glycogenolysis and the mechanism of action of adrenaline in amphibian liver in vitro.

In in vitro cultures of liver from Ambystoma mexicanum glycogenolysis was stimulated by adrenaline, glucagon, and vasopressin in a dose-dependent manner. Maximum activity was seen at 10(-6) M hormone while 10(-9) M was without effect. Dibutyryl cyclic AMP (10(-3) M) stimulated glycogenolysis maximally although 10(-5) M had no effect. The glucose release brought about by adrenaline was blocked by the beta-adrenergic antagonist propranolol but not by prazosin or yohimbine which are alpha 1- and alpha 2-adrenergic antagonists. Cyclic AMP concentrations in liver were elevated within 1 min of administration of adrenaline and remained elevated for at least 60 min. Phosphorylase a activity was elevated 10 min after addition of adrenaline and remained elevated for at least 6 hr. The rise in hepatic cyclic AMP concentration and phosphorylase a activity was largely blocked by propranolol. These findings are consistent with adrenaline acting via a beta-adrenergic receptor in A. mexicanum. Glycogenolysis in A. mexicanum liver was stimulated by isoprenaline and phenylephrine and in each case the stimulation was reduced in the presence of propranolol but unaffected by phentolamine. High concentrations of methoxamine, a specific alpha 1-agonist, had no effect upon glycogenolysis. These findings suggest that alpha-adrenergic receptors play no role in regulation of glycogenolysis in A. mexicanum.

A high incidence of abdominal pregnancy in the Djungarian hamster (Phodopus sungorus).

Eight animals with abdominal fetuses were found in a relatively small colony of Djungarian hamsters. All the fetuses were macerated. Some had remains of an amniotic sac with an umbilical attachment to a placenta adherent to the peritoneum, but others were without placental remains. Gross and histological examinations failed to reveal any ruptures of the uterus or oviducts. It was not possible to decide whether the abdominal pregnancies were primary or secondary.