Recurrent Papillary Bladder Tumors in a Boy With Lynch Syndrome

Lynch syndrome (LS) is an autosomal dominant genetic disorder defined by germline mutations in one of four mismatch repair genes including PMS2, MLH2, MSH1, MSH2, or deletion in the EPCAM gene.1 The most common urologic manifestation of LS is upper tract urothelial carcinoma, which occurs in up to 20% of patients with LS.2 While data are scarce, there is growing evidence of an increased relative risk of bladder malignancy in patients with LS.3,4 Bladder tumors in children are a rare entity and the link between pediatric bladder tumors and LS has not been previously reported to our knowledge.

Retrospective study to estimate the prevalence and describe the clinicopathological characteristics, treatments received, and outcomes of HER2-low breast cancer

BACKGROUND

Approximately 80% of all breast cancers (BCs) are currently categorized as human epidermal growth factor receptor 2 (HER2)-negative [immunohistochemistry (IHC) 0, 1+, or 2+/in situ hybridization (ISH) negative]; approximately 60% of BCs traditionally categorized as HER2-negative express low levels of HER2. HER2-low (IHC 1+ or IHC 2+/ISH-) status became clinically actionable with approval of trastuzumab deruxtecan to treat unresectable/metastatic HER2-low BC. Greater understanding of patients with HER2-low disease is urgently needed.

PATIENTS AND METHODS

This global, multicenter, retrospective study (NCT04807595) included tissue samples from patients with confirmed HER2-negative unresectable/metastatic BC [any hormone receptor (HR) status] diagnosed from 2014 to 2017. Pathologists rescored HER2 IHC-stained slides as HER2-low (IHC 1+ or IHC 2+/ISH-) or HER2 IHC 0 after training on low-end expression scoring using Ventana 4B5 and other assays at local laboratories (13 sites; 10 countries) blinded to historical scores. HER2-low prevalence and concordance between historical scores and rescores were assessed. Demographics, clinicopathological characteristics, treatments, and outcomes were examined.

RESULTS

In rescored samples from 789 patients with HER2-negative unresectable/metastatic BC, the overall HER2-low prevalence was 67.2% (HR positive, 71.1%; HR negative, 52.8%). Concordance was moderate between historical and rescored HER2 statuses (81.3%; κ = 0.583); positive agreement was numerically higher for HER2-low (87.5%) than HER2 IHC 0 (69.9%). More than 30% of historical IHC 0 cases were rescored as HER2-low overall (all assays) and using Ventana 4B5. There were no notable differences between HER2-low and HER2 IHC 0 in patient characteristics, treatments received, or clinical outcomes.

CONCLUSIONS

Approximately two-thirds of patients with historically HER2-negative unresectable/metastatic BC may benefit from HER2-low-directed treatments. Our data suggest that HER2 reassessment in patients with historical IHC 0 scores may be considered to help optimize selection of patients for treatment. Further, accurate identification of patients with HER2-low BC may be achieved with standardized pathologist training.

Palliative Cytoreductive Surgery With or Without Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Carcinomatosis: Is It Safe and Effective?

INTRODUCTION

Palliation is a controversial indication for cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Patients with peritoneal carcinomatosis (PC) are living longer, and the roles of palliative CRS and HIPEC are increasingly challenged. The purpose of this study is to evaluate indications, morbidity, and symptom improvement from CRS/HIPEC in advanced PC.

METHODS

A retrospective review of patients undergoing CRS and/or HIPEC with a palliative intent at a single institution from February 2008 to February 2018 was performed. Main end points included symptom improvement, symptom-free interval, and overall survival.

RESULTS

Two hundred and seventy seven patients were referred for CRS/HIPEC during the study period and 17 underwent 20 palliative procedures. Appendiceal (n = 6) and colorectal cancers (n = 6) were the most common malignancies. Ascites (n = 8) and bowel obstruction (n = 8) were the most common indications for intervention. The postoperative complication rate was 50% and major complication rate was 20%. Partial symptom improvement or resolution of symptoms was achieved in 18 (90%) cases. A durable symptom control at 90 d was achieved in 13 (65%) cases. The median time to symptom recurrence was 5.1 mo (interquartile range: 2-11.4), and the median overall survival was 11.6 mo (interquartile range: 3.8-28.5).

CONCLUSIONS

Palliative CRS and/or HIPEC achieve symptom improvement in patients with advanced PC. Risk assessment and expected time to recovery from surgery remain paramount for patient selection.

Preoperative Diabetes Optimization Program

IN BRIEF "Quality Improvement Success Stories" are published by the American Diabetes Association in collaboration with the American College of Physicians, Inc., and the National Diabetes Education Program. This series is intended to highlight best practices and strategies from programs and clinics that have successfully improved the quality of care for people with diabetes or related conditions. Each article in the series is reviewed and follows a standard format developed by the editors of Clinical Diabetes. The following article describes a successful effort to improve glycemic control in presurgical patients with an A1C >8%.

Language barriers and paediatric burns: Does education make a difference?

A focused first aid education campaign was conducted in Sydney in 1996 for parents of children from Non-English speaking backgrounds (NESB) to improve their knowledge of correct burns first aid treatment (BFAT). This study sought to determine the correlation, if any, between the reported beneficial results of this education campaign and the subsequent severity of burns in children. A retrospective review of all patients admitted to the state Burns Unit at The Children's Hospital at Westmead (CHW) over a 7-year period from January 1995 to December 2001 was performed. Number of patients, language spoken at home (English, Chinese, Arabic, Vietnamese or Other) and the rate of burns requiring skin grafting was assessed. A total of 1,283 patients were admitted over 7 years. Skin grafting was required in 544 (42%). NESB children required grafting in up to 88% of cases prior to the first aid education campaign, reducing to a minimum of 37% at 1 year and 65% at 5 years following the campaign. This compared to 40 and 36%, respectively, for English speaking children. While the initial decrease in grafting requirements may reflect an effective education campaign, the subsequent rise suggests the need for reinforcement.

Telemedicine diagnosis for fetal alcohol syndrome - The Manitoba experience

The diagnosis of fetal alcohol syndrome has been possible, with increasing precision, since the original descriptions in the 1970s. Multidisciplinary diagnostic approaches have been recognized as most appropriate, although they are often not available. Telemedicine has been used in Canada over the same time period for a variety of diagnositc applications.Since 1999, funding by the Manitoba government has allowed the consolidation of services for children with prenatal alcohol exposure in Manitoba, and has allowed the development of a format for diagnosis using telemedicine.This paper describes the authors' experience with the above and offers observations that may be helpful to other programs that are focused on developing this format for the diagnosis of fetal alcohol syndrome.

Pharmacodynamics of flunixin and ketoprofen in mallard ducks (Anas platyrhynchos)

Flunixin (FLX) and ketoprofen (KET) are potent nonsteroidal anti-inflammatory drugs (NSAIDs) used to alleviate pain and decrease inflammation. These drugs block access of arachidonic acid to its binding site on the cyclooxygenase enzyme, thus preventing conversion to thromboxane A2 and subsequent degradation to thromboxane B2 (TBX). Consequently, plasma TBX may be used to estimate duration of NSAID action. Sixteen adult mallard ducks (Anas platyrhynchos) were randomly assigned to three treatment groups: control (n = 4), FLX 5 mg/kg (n = 6), or KET 5 mg/kg (n = 6). Blood samples were taken 1 hr prior to and just before (0 hr) injection and 0.25, 0.5, 1, 2, 4, 6, 12, 24, 36, and 48 hr after injection. Plasma samples were analyzed for corticosterone and TBX. The feces were tested for the presence of hemoglobin and the ducks were euthanized for complete necropsy at the end of the study. Samples of muscle, kidney, liver, proventriculus, and intestine were taken for histologic analysis. Thromboxane was suppressed significantly in all birds following administration of either FLX or KET for 4 hr and decreased for approximately 12 hr compared with baseline samples (-1 and 0 hr). In the control group, TBX gradually declined over time. None of the ducks showed evidence of gastrointestinal bleeding, but the FLX group had muscle necrosis present at injection sites. FLX and KET likely exert pharmacological effects for at least 12 h. Although degree of TBX inhibition cannot be correlated absolutely with degree of analgesia or anti-inflammatory effects, it is possible that these effects are present during this time. This work suggests that FLX and KET can potentially be used as anti-inflammatory and analgesic agents in waterfowl. However, because of muscle necrosis at the injection site, we do not recommend parenteral use of FLX in ducks.

Ethanol utilization by sulfate-reducing bacteria: an experimental and modeling study

A mixed culture of sulfate-reducing bacteria containing the species Desulfovibrio desulfuricans was used to study sulfate-reduction stoichiometry and kinetics using ethanol as the carbon source. Growth yield was lower, and kinetics were slower, for ethanol compared to lactate. Ethanol was converted into acetate and no significant carbon dioxide production was observed. A mathematical model for growth of sulfate-reducing bacteria on ethanol was developed, and simulations of the growth experiments on ethanol were carried out using the model. The pH variation due to sulfate reduction, and hydrogen sulfide production and removal by nitrogen sparging, were examined. The modeling study is distinct from earlier models for systems using sulfate-reducing bacteria in that it considers growth on ethanol, and analyzes pH variations due to the product-formation reactions.

Microbial sulfate reduction in a liquid-solid fluidized bed reactor

A liquid-solid fluidized bed reactor was used to carry out sulfate reduction with a mixed culture of sulfate reducing bacteria. The bacteria were immobilized on porous glass beads. Stable fluidized bed operation with these biofilm-coated beads was possible. The low specific gravity of the hydrated beads allowed operation at low liquid recirculation rates. H(2)S level in the reactor was controlled by N(2) sparging, which also served as the location for liquid feed and removal. Ethanol was used as the electron donor/carbon source for the bacteria. Sulfate reduction rates up to 6.33 g sulfate L(-1) day(-1) were attained in the reactor at a hydraulic retention time of 5.1 h. The effect of hydraulic retention time and biomass loading on the beads, on reactor performance, and efficiency were examined. The efficiency of sulfate reduction increases considerably as the hydraulic retention increases, until the bacteria became very strongly substrate-limited at 55h HRT. The effect of bead biomass loading on bed expansion at various liquid superficial velocities was studied. A model for the reactor was developed. Simulations of the continuous flow experiments indicate that the model can describe the system well, and thus could be used in the design/scale-up of such reactors. The model suggests that a significant increase in the sulfate reduction capacity of the system is possible by increasing the volume of the bed relative to the total liquid volume of the system.

Mechanism of action of nonsteroidal anti-inflammatory drugs

After more than a century of use, pharmacologists thought they had discovered the mechanism of action of nonsteroidal anti-inflammatory drugs (NSAIDs) when their inhibitory action on the production of prostaglandins was described. This action was located at the inhibition of the enzyme responsible for the conversion of arachidonic acid to prostaglandins, namely cyclo-oxygenase. More recently, it has been recognized that more than one isoform of the enzyme exists. The two forms of cyclo-oxygenase described are widely different in their location, activity, and role, especially because the COX-1 isoenzyme seems to be mainly a constitutive enzyme whereas the COX-2 isoenzyme is inducible. This separation of activity appears to be correlated with the separation of function of the various prostaglandins, whereas the constitutive form is associated with "physiologic" functions and the inducible form with inflammatory responses. Recent advances have included the development of drugs with a high specificity toward the inducible enzyme (COX-2) to focus on the anti-inflammatory actions, because many of the unwanted side effects of NSAIDs have been associated with inhibition of the constitutive isoform (COX-1). Other recent developments in studies of the NSAIDs have included potential therapeutic actions in other degenerative conditions.

If the gut works use it

Using education and increased monitoring, a nutritional support team lowered parenteral nutrition days from 84 to 5 per quarter, increased the proportion of patients meeting their nutritional requirements from 75% to 97%, and saved money.

An extractive membrane biofilm reactor for degradation of 1,3-dichloropropene in industrial waste water

A bacterial biofilm, capable of mineralising a technical mixture of cis- and trans-1,3-dichloropropene (DCPE), was enriched on the biomedium side of an extractive membrane biofilm reactor (EMBR). The membrane separates the biomedium from the industrial waste water, in terms of pH, ionic strength and the concentration of toxic chemicals. The biofilm, attached to a silicone membrane, is able to mineralize DCPE after its diffusion through the membrane. Five bacterial strains with degradation capabilities were isolated from the metabolically active biofilm and further investigated in batch experiments. Two of them, Rhodococcus erythropolis strains EK2 and EK5, can grow with DCPE as the sole carbon source. Pseudomonas sp. EK1 uzilizes cis-3-chloroallylalcohol and cis-3-chloroacrylic acid, whereas the metabolite trans-3-chloroacrylic acid represents a dead-end product of the pathway of this strain. The other two strains, Delftia sp. EK3 and EK4, although unable to grow with DCPE as the carbon source, can transform DCPE and its upper-pathway intermediates at reasonable conversion rates. They may represent helper functions of the biofilm consortium, which mineralised up to 12.5 mmol DCPE per hour per gram of biomass protein. Higher feed rates in the EMBR (up to 15 mmol per hour per 100-l bioreactor volume) and shock loads corresponding to concentrations up to 1.8 mmol l-1 led to a significant increase in the freely floating bacterial biomass in the reactor medium (OD546 = 0.2). At the standard operating feed rate of 1.8 mmol h-1, the free biomass concentration was very low (OD546 = 0.04).

Measurement of mechanical thresholds, plasma cortisol and catecholamines in control and lame cattle: a preliminary study

The threshold response to a mechanical nociceptive stimulus was significantly lower on the lame hind limb of lame cows than on the same limb of sound cows. There were no significant differences between the concentrations of cortisol, noradrenaline, adrenaline or dopamine in the blood plasma of the sound and lame cows.

Single dose pharmacokinetics of medetomidine in sheep

The pharmacokinetics of medetomidine hydrochloride (Domitor) administered at a single dose of 15 micrograms/kg i.v. in sheep are described. Plasma medetomidine concentrations were determined using a sensitive radioreceptor assay technique, capable of also measuring metabolites which would bind to alpha 2 adrenergic receptors. Medetomidine was rapidly distributed, with a half-life of distribution of 4.65 +/- 0.65 min. The apparent volume of distribution was 2.69 +/- 0.62 L/kg, while elimination half-life was 37.85 +/- 2.84 min. Total body clearance varied between 16.29 and 151.81 mL/min.kg. Pharmacological effects of medetomidine paralleled its plasma concentration.

Central sensitization as a result of surgical pain: investigation of the pre-emptive value of pethidine for ovariohysterectomy in the rat

The development of central hypersensitivity as a result of a routine surgical procedure, midline ovariohysterectomy, was investigated in rats using the paw pressure test (PPT) and tail-flick latency (TFL) tests of spinal reflex activity. In addition, the modulating effect of pre-emptive versus post-operative administration of pethidine (a short-acting pure mu-opioid agonist) on the development of central hypersensitivity was studied. Initial experiments indicated that pethidine (15 mg/kg, i.m.) gave sub-maximal increases in thresholds for 60 min, and also that the administration of an anaesthetic did not unduly prolong the action of pethidine. Subsequently, 24 female Wistar rats were allocated to 1 of 4 treatment protocols: (1) anaesthesia without analgesics; (2) anaesthesia and surgery (midline ovariohysterectomy) without analgesics; (3) anaesthesia and surgery with pre-operative administration of pethidine; (4) anaesthesia and surgery with post-operative administration of pethidine. Thirty-five minutes after the end of anaesthesia thermal and mechanical nociceptive thresholds were measured at stepwise increasing intervals for 480 min. Changes were expressed as percentage changes from baseline (PPT) or deviation from expected values (TFL). Area under the threshold versus time response curves (AUCs) were also calculated for the following time sectors: 30-90, 90-150, 150-270, 270-390 and 390-510 min post-anaesthetic. Results of the TFL testing did not indicate the development of any significant hyperalgesia in any groups, but the results of the PPT did. In the time sectors 150-270 and 270-390 min post-anaesthetic, the AUCs in rats subjected to anaesthesia and surgery with either post-operative administration of pethidine or surgery with no analgesic drug administration, were significantly lower than the AUCs in rats given analgesics pre-operatively or those subjected to general anaesthesia alone (P < 0.01), Mann-Whitney). In summary, it appears that pethidine, in this protocol, prevented the development of surgically induced hyperalgesia when it was given pre-emptively.

A field study of the effect of lameness on mechanical nociceptive thresholds in sheep

Threshold responses to a mechanical pressure test were measured in two groups of adult female sheep taken from 27 flocks in north Devon. The first group consisted of 470 healthy sheep and the second of 139 sheep suffering from obvious lameness, clinically diagnosed as foot rot. The lame sheep were assessed for the severity of the lesion and the level of lameness and assigned a score. In flocks with sheep with a severe degree of lameness, the sheep had a significantly lower threshold to a mechanical nociceptive stimulus than their matched sound controls and their thresholds remained low when tested three months later, after the apparent resolution of the foot rot lesion. In flocks where the lame sheep were less severely affected there was no difference in the threshold responses to a mechanical stimulus between the sound and lame sheep.

The effects of opioid and alpha 2 adrenergic blockade on non-steroidal anti-inflammatory drug analgesia in sheep

The analgesic effects of the non-steroidal anti-inflammatory drugs (NSAIDs) flunixin and dipyrone were assessed in healthy sheep with no pre-existing inflammation, and in sheep with a chronic inflammatory lesion, using a mechanical noxious stimulus. Saline and dexamethasone were given as controls. Blood taken from healthy sheep after NSAID administration was assayed for thromboxane B2 (TxB2) to compare the ability of these drugs to inhibit cyclo-oxygenase. Both flunixin and dipyrone produced a small but statistically significant rise in pain thresholds (18% and 21% of maximum possible effect respectively) in the healthy sheep which peaked at 30 min and had returned to pre-drug values by 2-3 h. In the lame sheep a similar effect occurred but the response was smaller, much more variable and tended to be prolonged. Saline and dexamethasone had no effect on thresholds over 6 h in either group of sheep. The rise in thresholds was prevented by pre-treatment with naloxone (an opioid antagonist) or atipamezole (an alpha 2-adrenergic antagonist) in the healthy sheep. Naloxone and atipamezole had no effect on thresholds when given alone to healthy sheep. Both NSAIDs inhibited the production of TxB2 to a similar extent. These results indicate that central mechanisms may be involved in NSAID analgesia.

Radioreceptor assay for determination of xylazine and medetomidine in sheep plasma

A radioreceptor assay technique is described for the measurement of xylazine and medetomidine in sheep plasma. The assay was based on the displacement of tritiated clonidine from a2-adrenoceptors in a rat brain homogenate by xylazine or medetomidine extracted from plasma. Plasma samples from sheep which had been given xylazine and medetomidine were treated with alumina to remove endogenous catecholamines which would otherwise have bound to alpha 2-adrenoceptors and interfered with the assay. The drugs were then extracted using chloroform, reconstituted in buffer and used to displace [3H]clonidine. The concentration of alpha 2-agonist was calculated by reference to standard curves. The method had a detection limit of 2.5 ng/mL for xylazine and 0.24 ng/mL for medetomidine. The assay could also be used to detect metabolites capable of binding to alpha 2-receptors.

Antinociceptive activity of midazolam in sheep

The purpose of this study was to examine the effects of midazolam on the nociceptive threshold responses in sheep. The intravenous administration of midazolam (0.1-0.3 mg/kg) produced a significant dose-dependent elevation of the mechanical and thermal nociceptive thresholds. The intravenous administration of flumazenil (20 micrograms/kg) markedly attenuated the antinociceptive activity of midazolam in the mechanical nociceptive test, whereas intravenous naloxone (0.2 mg/kg) had no significant effect on midazolam-mediated analgesia. The intrathecal administration of midazolam (1 mg), via chronically implanted cervical subarachnoid catheters, produced a significant elevation in the mechanical threshold responses. These results indicate that midazolam has antinociceptive actions in the sheep and suggest that this effect is, at least partially, mediated at the spinal level.

Effect of chronic pain associated with lameness on plasma cortisol concentrations in sheep: a field study

Plasma cortisol concentrations were measured in two groups of sheep taken from 29 flocks in north Devon. The first group were healthy adult females and the second group were adult females suffering from footrot in one forefoot. These sheep were assessed for the severity of the lesion and the level of lameness and assigned a score. The plasma cortisol concentration was significantly higher in the lame sheep than in the healthy sheep and remained so for up to three months after the apparent resolution of the clinical lesion. There was no correlation between the severity of the footrot and the concentration of plasma cortisol.

Antinociceptive effects of combining low doses of neuroleptic drugs and fentanyl in sheep

Effects of low doses of the neuroleptic drugs droperidol and zuclopenthixol, combined with a subanalgesic dose of the opioid mu-agonist, fentanyl, on mechanical nociceptive thresholds were evaluated in sheep. Intravenously administered droperidol (5 micrograms/kg of body weight) did not induce any change in the nociceptive thresholds when administered alone, but caused marked increase in threshold responses when combined with a subanalgesic dose of fentanyl (5 micrograms/kg). Similarly, a combination of i.v. administered zuclopenthixol (100 micrograms/kg) and fentanyl induced significant (P < 0.05) antinociceptive effects, whereas zuclopenthixol administered i.v. alone had no effect on the threshold responses. Intrathecal administration of a low dose of droperidol (5-micrograms total dose) combined with i.v. administered fentanyl also increased mechanical thresholds significantly (P < 0.05). These results indicate that interactions exist between dopaminergic and opioid systems in the processing of nociceptive information and that these effects may, at least partially, be mediated spinally.

Endocardial pacing, cardioversion and defibrillation using a braided endocardial lead system

The clinical efficacy and safety of a second-generation braided endocardial pacing, cardioversion and defibrillation lead system was evaluated in 25 patients with ventricular tachycardia (VT) or ventricular fibrillation (VF). The lead system consisted of two 8Fr active fixation endocardial leads each with pacing and defibrillation electrodes and a thoracic patch electrode. Monophasic and biphasic shocks were delivered using a triple-electrode configuration with a right ventricular common cathode and right atrial and thoracic patch anodes. VT and VF were electrically induced. Rapid VT (rate > or = 180 beats/min) and VF were initially terminated by 20 J (550 V) shocks and slow VT (rate < 180 beats/min) by 10 J (400 V) shocks. One hundred fourteen episodes (rapid VT/VF 73, slow VT 41) were treated with 128 shocks (monophasic 80, biphasic 48). Mean ventricular pacing threshold was 0.7 +/- 0.5 ms before and 0.9 +/- 0.5 ms after endocardial shock delivery (p > 0.2). Mean ventricular electrogram amplitude in sinus rhythm was 11.9 +/- 5.7 mV before and 11.4 +/- 5.1 mV after shock delivery (p > 0.2). Simultaneous monophasic endocardial shocks terminated 53% of VF episodes at < or = 20 J. Simultaneous biphasic shocks terminated 94% of all VF episodes at < or = 20 J (p < 0.03). Efficacy of > or = 10 J shocks for rapid VT/VF was greater for biphasic (92%) versus monophasic (74%) shocks (p < 0.05) at lower average shock energy (15 +/- 7 J vs 19 +/- 7 J, respectively, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

The spinal antinociceptive activity of the alpha 2-adrenoceptor agonist, xylazine in sheep

1. The intrathecal administration of xylazine (100 micrograms), via a chronic indwelling, cervical intrathecal catheter, produced a marked elevation of the mechanical nociceptive thresholds in the sheep. This antinociceptive effect was abolished by the prior intrathecal administration of the alpha 2-adrenoceptor antagonist, idazoxan. 2. The intrathecal administration of the selective alpha 2-antagonists, idazoxan (100 micrograms) and RX811059 (33 micrograms), significantly attenuated the antinociceptive activity of intravenous xylazine, with a 60-65% reduction in the area under the antinociceptive curve. The intrathecal administration of the antagonists alone had no significant effect on nociceptive thresholds. 3. Examination of the distribution of tritiated idazoxan (25 microCi in 100 microliters) indicated that the site of action of the drug was limited to the cervical spinal cord after intrathecal administration. 4. These studies demonstrate that a significant proportion of the antinociceptive effect of systemically administered xylazine is mediated by spinal alpha 2-adrenoceptors.

A technique for recording from spinal neurones in awake sheep

A technique is described for implanting a chamber on 1 or 2 vertebrae of the spinal column of the sheep. This chamber protrudes permanently through the dorsal skin of the back and is covered by a light bandage. Between recording sessions the chamber houses an inner cap sealing the hole that gives access to the cord. During recording sessions this cap is removed and a miniature manipulator inserted instead. This manipulator can accept a motor drive that holds a glass-coated tungsten microelectrode. The drive has a hole through which an arthroscope tube can be passed so that insertion of the electrode can be performed under visual control. Extracellular recordings have been made of single spinal neurones for up to 4 h in animals that are drug-free, untrained and only lightly restrained. Recording sessions can be repeated on a daily basis for several weeks until the dura and/or arachnoid becomes too thickened to permit electrode penetrations. Animals remain healthy and their behaviour remains normal throughout this time.

Analgesic effects of detomidine in thoroughbred horses with chronic tendon injury

This study was undertaken to assess the analgesia provided by detomidine (20 micrograms kg-1 intravenously) in thoroughbred horses. Pain thresholds to a mechanical noxious stimulus were measured before and after a period of mild chronic pain in one foreleg. Detomidine was a good analgesic in control animals; their pain thresholds were significantly elevated for about 60 minutes. After injury, the injured leg had a significantly lower pain threshold and the intensity and duration of analgesia provided by detomidine were significantly reduced. The analgesia in the opposite (sound) leg was also reduced, indicating that there were both central and peripheral aspects to this increased sensitivity to painful stimuli. Detomidine deserves to be considered as a potent analgesic in the horse rather than a sedative with analgesic side effects.

Effects of clinically occurring chronic lameness in sheep on the concentrations of plasma noradrenaline and adrenaline

Plasma adrenaline (AD) and noradrenaline (NA) concentrations were measured by high performance liquid chromatography with electrochemical detection in blood samples from control and lame sheep. The lame sheep suffered from naturally occurring foot rot and showed behavioural characteristics normally associated with chronic pain. The lame sheep were scored both for impairment of gait and pathology of the foot and divided into mild and severely affected groups. Both the mildly and severely lame group showed a significant increase in plasma AD and plasma NA which tended to persist even after clinical resolution of the condition. The measurement of plasma AD and NA may provide information which can be used to assess animals experiencing chronic pain, when taken in conjunction with other parameters, such as nociceptive thresholds and plasma hormone levels.

Dietary impact on biliary lipids and gallstones

Although dietary factors influence bile lithogenicity and gallstone formation, the main dietary effect appears to be indirect, depending on an interaction between caloric consumption and gender-specific aspects of lipoprotein metabolism. Excessive energy intake elicits its detrimental effect by altering lipoprotein and hepatic cholesterol metabolism in association with hyperinsulinemia. Factors, dietary and genetic, that favor elevated hepatic cholesterol synthesis and production of a bile acid profile in which chenodeoxycholic acid predominates appear to be associated with lithogenic bile. An inconsistent effect of dietary fat saturation on gallstones is that polyunsaturates possibly increase risk in men and decrease risk in women. Vegetable protein may reduce the risk of cholelithiasis. Whereas both the amount and type of dietary fiber influence cholesterol and bile lipid metabolism, specific associations between fiber and gallstones in humans remain elusive.

Venom immunotherapy: 10 years of experience with administration of single venoms and 50 micrograms maintenance doses

For the past 10 years, we have administered venom immunotherapy with single venoms, whenever it is possible, and maintenance doses of 50 micrograms. The choice of venoms was based on clinical history, skin test reactions, and a knowledge of venom cross-reactivity. There have been 258 re-stings in 108 patients with only three systemic reactions (2.7% per patient; 1.2% per sting). Two of these re-stings reactions were very mild, hives and facial edema, in patients who had had initial severe anaphylaxis. Five other patients had transient ill-defined symptoms, not considered allergic after re-stings. The patients covered a wide age range. Twenty-seven patients, nine under age 16 years, had initial dermal reactions only, and 44 patients had severe anaphylaxis. Most patients had multiple positive skin tests. Seventy-five patients received single venoms (yellow jacket, 58; honeybee, 15; hornet, 2), and 30 patients received two venoms. Re-stings occurred from 1 month to 8 years, (mean, 2 years) after starting treatment. Results indicate that this approach with 50 micrograms top doses and single venom immunotherapy may be sufficient in most patients with an associated decrease in the cost as well as possible increased morbidity associated with the use of multiple venom antigens.

Chronic intrathecal catheterization in the sheep

This paper describes a relatively simple and noninvasive method for the chronic implantation of intrathecal catheters in the sheep. The technique has been carried out on 17 occasions in nine sheep, with 60% of attempted catheterizations producing a correctly positioned, functional catheter. The placement and integrity of the catheters were confirmed by radiography using a contrast medium. Correctly placed catheters have been maintained for up to 16 months without problems.

The autoradiographic binding of [3H] quinuclidinyl benzilate to muscarinic receptors in the spinal cord of the sheep

Autoradiography of [3H] quinuclidinyl benzilate was used to demonstrate the distribution of muscarinic acetylcholine binding in the spinal cord of sheep. Binding was confined to the grey matter of the cord, and was most densely distributed in the substantia gelatinosa region of the dorsal horn, the lamina X region around the central canal, the intermediolateral columns and in various regions of the ventral horn. The use of specific M1 and M2 receptor subtype ligands, pirenzipine and 4-DAMP indicated that both receptor subtypes were present in most regions of dense binding.

Further studies on the antinociceptive activity and respiratory effects of buprenorphine in sheep

The thermal and mechanical analgesic profile of buprenorphine at a dose rate of 1.5 micrograms/kg i.v. was investigated in five sheep. This dose produced significant analgesia for 40 min against the thermal stimulus, but no mechanical antinociception. A higher dose rate of 12 micrograms/kg also failed to produce antinociception to a mechanical stimulus. In addition, the effect of the drug (6 micrograms/kg) on respiratory gas tensions was determined and no significant changes were observed.

Effects of chronic lameness on the concentrations of cortisol, prolactin and vasopressin in the plasma of sheep

Plasma cortisol, prolactin and vasopressin concentrations were measured by radioimmunoassay in blood samples from control and lame sheep. The lame sheep were all suffering from naturally occurring clinical cases of footrot and showed all the behavioural characteristics of chronic pain; they were scored for impairment of gait and pathology of the foot and divided into mild and severely lame groups. The severely lame sheep had increased plasma prolactin and decreased plasma cortisol concentrations. Plasma vasopressin was variable and showed no consistent changes with lameness. The relationships between plasma cortisol, prolactin and vasopressin may be a useful index in the assessment of animals experiencing chronic pain, when taken in conjunction with other measurements.

Analgesic activity and respiratory effects of butorphanol in sheep

The analgesic drug butorphanol tartrate has proved useful clinically in horses and dogs but its analgesic profile had not yet been investigated in sheep. This study was initiated to determine the thermal and mechanical antinociceptive activity of butorphanol (at the dose rates 0.05, 0.1 and 0.2 mg kg-1) in sheep. The drug produced significant analgesia in the thermal test system, the duration of which was dose related but no significant elevation in mechanical pressure thresholds could be detected. In a further set of experiments the dose rate was increased to 0.4 mg kg-1 and mechanical testing was repeated. There was still no clinically significant elevation in pressure thresholds. At a dose rate of 0.2 mg kg-1 the drug had no detectable effect on respiratory blood gas tensions. Behavioural changes were severe if a dose rate of 0.2 mg kg-1 was exceeded.

The influence of chronic pain on the analgesic effects of the alpha 2-adrenoceptor agonist, xylazine, in sheep

A comparison of the analgesic potency of the alpha 2-adrenoceptor agonist, xylazine, in control healthy sheep and sheep suffering chronic pain from footrot, indicated that the analgesic effectiveness of xylazine was significantly reduced in the animals experiencing chronic pain. This was measured by recording the threshold to a mechanically applied pressure stimulus. Furthermore, when the condition was apparently resolved, by conventional treatment over a period of 2 to 3 weeks, the decreased analgesic effectiveness of the alpha 2-agonist was still apparent although the animals were clinically cured of the footrot.