4-[4-[(2-Hydroxybenzoyl)amino]phenyl]butyric acid as a novel oral delivery agent for recombinant human growth hormone

A series of N-acetylated, non-alpha, aromatic amino acids was prepared and shown to promote the absorption of recombinant human growth hormone (rhGH) from the gastrointestinal tract. Seventy compounds in this family were tested in vivo in rats. Of the compounds tested, 4-[4-[(2-hydroxybenzoyl)amino]phenyl]butyric acid was identified as a preclinical candidate and was used to demonstrate the oral delivery of rhGH in primates. A significant positive correlation was found between the relative log k' of the delivery agents, as determined by HPLC on an immobilized artificial membrane (IAM) column, and serum rhGH concentrations following oral or colonic dosing in rats. Structure-activity relationships have also been developed on the basis of electronic effects and hydrogen-bonding characteristics of the aromatic amide substituents.

Toxicologic evaluation of a high-selenium hay diet in captive pronghorn antelope (Antilocapra americana)

Five captive-raised pronghorn antelope (Antilocapra americana) were fed an alfalfa-grass hay diet containing 15 ppm total dietary selenium (Se) for 164 days. Four additional captive-raised pronghorns fed a similar diet containing approximately 0.3 ppm total dietary Se served as controls. None of the pronghorns had clinical signs attributable to the high Se hay. Plasma Se increased more rapidly than blood Se concentrations, from baseline concentrations (< 0.15 g/ml) to > 0.40 g/ml within the first 50 days on the high selenium diet, but thereafter declined to approximately 0.30 microgram/ml. Mean primary antibody response to hen egg albumin was less in pronghorn on Se hay. No significant gross or histological lesions attributable to selenosis were found, nor was there any evidence of dystrophic hoof growth. The greatest Se tissue concentrations were found in liver and kidney (5.67 to 10.4 micrograms/g and 2.36 to 3.14 micrograms/g, respectively) from experimental animals; liver and kidney from the controls contained considerably less (< or = 0.52 microgram/g and < or = 0.61 microgram/g, respectively). Exposure of pronghorns for more than 5 mo to a diet containing 15 ppm Se caused significant increases in plasma, liver and kidney Se concentrations, in the absence of clinical disease or pathologic lesions due to selenosis. Based on these results, we propose that pronghorns are less susceptible to selenosis than previously reported and that diagnostic criteria for the disease should be modified.

Myositis, lameness, and paraparesis associated with use of an oil-adjuvant bacterin in beef cows

Right hind limb lameness, progressing to bilateral paraparesis, was observed in 56 of 610 (9%) beef cows. Lameness began 6 days to 4 weeks after vaccination in the right longissimus lumborum (loin) muscle with an Escherichia coli/Campylobacter bacterin in an oil adjuvant. Postmortem examination of 5 affected cows revealed a large inflammatory mass at the site of vaccination. In each cow, the mass spread through adjacent intervertebral foramina into the vertebral canal and compressed the lumbar portion of the spinal cord. Microbiologic procedures did not reveal a microbial agent in affected tissues or in an unopened bottle of bacterin from the same lot used in the herd. Histologic examination revealed pyogranulomatous inflammation of the vaccination site and adjacent epidural tissue, with inflammatory nodules centered around large clear spaces that probably represented remnant emulsion from the oil adjuvant in the bacterin. As evident in these cows, IM injection of irritating products may cause severe myositis. Vaccination into paravertebral muscles is risky because of possible extension of inflammation through intervertebral foramina.

Investigation of sheep-associated malignant catarrhal fever virus infection in ruminants by PCR and competitive inhibition enzyme-linked immunosorbent assay

Development of control measures for the gammaherpesviral disease of cattle known as sheep-associated malignant catarrhal fever (SA-MCF) has been hampered by a lack of accurate diagnostic tests either for the causative virus or for antibody against that virus. A recently developed competitive-inhibition enzyme-linked immunosorbent assay (CI-ELISA) for the detection of antibody to malignant catarrhal fever (MCF) virus (MCFV) in ruminants based on a monoclonal antibody to a widely conserved epitope of MCFV (H. Li, D. T. Shen, D. P. Knowles, J. R. Gorham, and T. B. Crawford, J. Clin. Microbiol. 32:1674-1679, 1994) and a PCR assay based on previously reported primers (S. I. F. Baxter, I. Pow, A. Bridgen, and H. W. Reid, Arch. Virol. 132:145-159, 1993) were used to detect anti-MCFV antibody and SA-MCFV DNA in sheep and other ruminants. The PCR amplified a specific 238-bp SA-MCFV genomic DNA fragment from peripheral blood lymphocytes of adult sheep and other ruminants with clinical MCF. Of 144 samples from randomly selected healthy adult sheep, 143 (99%) were positive by PCR and 136 (94%) were positive by CI-ELISA. The agreement between the two assays exceeded 95%. Of nine samples collected from cattle and deer with clinical MCF of apparent sheep origin, seven were CI-ELISA positive and all 9 were PCR positive. Among 59 serum samples from presuckling lambs, none contained antibody detectable by CI-ELISA. After suckling, maternal anti-MCFV antibody was detectable for about 10 +/- 3 weeks. Although all colostrum and milk samples from infected ewes were strongly PCR positive, the appearance of detectable SA-MCFV DNA in lambs was correlated generally with antibody patterns, which suggests that the natural infection event in sheep may not occur during the perinatal period but occurs sometime later in life.

Pathology of experimentally induced chronic selenosis (alkali disease) in yearling cattle

Prolonged oral exposure of cattle to elevated dietary selenium (Se) in forage and seleniferous plants in seleniferous areas of the western United States is associated historically with 2 clinical syndromes: alkali disease and "blind staggers." The potential for Se-induced disease in cattle and other species is considerable in areas with seleniferous shales, Se-accumulating plants, arid climates, and alkaline soils. These 2 Se-associated conditions were defined in the 1930s and 1940s, and the nosology of blind staggers is questionable. Seventeen yearling steers fed 0.15, 0.28, and 0.8 mg Se/kg body weight as selenomethionine or selenite for 120 days were euthanized and examined postmortem. Significant lesions were confined to 4 steers in the medium- and high-dose selenomethionine group and to 1 steer in the high-dose selenite group. Grossly, dystrophic hoof lesions developed in 2 steers, 1 of which had extensive separation of horn from lamellar and coronary epidermis and also lost hair from the tail switch. Histologically, tubules in the stratum medium of hooves from these 5 steers were replaced by islands of parakeratotic cellular debris, separated by more normal hoof matrix. Two of the 5 steers also had hyperplasia, acanthosis, parakeratosis, and disorganized germinal epithelium of varying severity in hoof epithelium, particularly at the tips of epidermal lamellae. These changes may distinguish the hoof lesions of chronic selenosis from those of chronic laminitis in cattle, in which dermal (chorial) changes predominate. In skin from the distal part of the tail of the animal that lost its switch, most follicles were atrophic and devoid of hairshafts and displayed dyskeratosis and mild superficial follicular keratosis. No significant lesions developed in tissues other than integument. Autometallographic staining for catalytic Se bonds in various tissues, including skin, liver, and kidney, revealed no positive staining of hair shafts; the correlation between stain intensity and dose group was poor. These findings indicate that dietary exposure for 4 months to 0.28 and 0.8 mg Se/kg in the form of selenomethionine and to 0.8 mg Se/kg in the form of sodium selenite reproduces in some cattle mild (subclinical) to severe (clinical) forms of alkali disease. No significant neurological, renal, or hepatic lesions developed, supporting the contention that blind staggers is caused by factors other than excessive dietary selenium.

Iatrogenic compressive lumbar myelopathy and radiculopathy in adult cattle following injection of an adjuvanted bacterin into loin muscle: histopathology and ultrastructure

Compressive lumbar myelopathy is a recognized iatrogenic complication of injecting water-in-oil vaccines into paravertebral sites of laboratory animals and chickens. Herein, we report the histologic and ultrastructural features of a similar complication in a herd of cattle. Iatrogenic posterior paresis developed over 34 days in 56 of 610 cows (9.2%) following injection of a commercial bacterin 11-34 days earlier into M. longissimus lumborum. The bacterin was composed of inactivated Escherichia coli and Campylobacter fetus ssp. venerealis in a proprietary adjuvant. Tissues were collected for histopathology from 9 affected cattle that died or were euthanized after clinical signs lasting 6-38 days. A range of tissues, including the injection site lesion and lumbar spinal nerve roots, was obtained for ultrastructural examination from a cow with paresis of 31 days duration. There was locally extensive pyogranulomatous myositis with fibrosis and necrosis in right M. longissimus lumborum. Extension of the lesion into the vertebral canal via spinal nerve foramina resulted in focal pyogranulomatous inflammation in epidural fat and in adjacent dura mater. There was axonal degeneration in dorsal, lateral, and ventral columns and chromatolysis of spinal motor neurons in lumbar spinal cord, secondary to compression. A distinctive histologic and ultrastructural feature of pyogranulomata was the presence of osmiophilic material at the center of inflammatory foci, surrounded by macrophages and giant cells that contained intracytoplasmic lipid droplets. Ultrastructural examination of entrapped spinal nerves revealed axonal degeneration and loss of myelinated and unmyelinated fibers, segmental demyelination with remyelination, axonal spheroid formation, and early axonal regeneration.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic generalized obliterative arteriopathy in cattle: a sequel to sheep-associated malignant catarrhal fever

Malignant catarrhal fever (MCF) in cattle is generally associated with a short clinical course and a high case fatality rate (90-95%). The lesions in cattle that survive acute MCF for a prolonged period or appear to recover have not been documented. In a naturally occurring outbreak of MCF in a herd of beef cattle in Wyoming, 7 of 84 yearling heifers (8.3% of replacement herd) and 2 of 230 cows (0.9% of cow herd) developed clinical signs of pyrexia, mucopurulent discharge, bilateral keratitis, and weight loss following contact with ewes that had lambed 34-62 days earlier. Six of 9 affected cattle were examined postmortem following clinical signs (CS) that developed 2-150 days earlier. Three cattle with CS for < or = 39 days had lesions of regional lymphadenopathy and widespread severe segmental lymphoid arteritis-phlebitis that were typical of acute MCF, and proliferative intimal lesions were present in a small proportion of arteries at days 20 and 39 of CS. By contrast, 3 cattle that survived to 90, 105, and 150 days after clinical onset had distinctive arterial lesions in multiple organs, characterized by proliferative concentric fibrointimal plaques, disrupted inner elastic lamina, focally atrophic tunica media, and vasculitis of variable severity. Immunohistochemical and ultrastructural examination of intimal plaques identified the predominant cellular component to be smooth muscle cells with a contractile phenotype. No viral structures were seen. Serologic studies, using a competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA) that detects antibody to an epitope broadly conserved among isolates of the MCF virus, found that 2 chronically affected cattle were serologically positive between days 42 and 100 of CS, with seroconversion in 1 animal between days 52 and 73 of CS. Seroprevalence was 7.9% in the 76 remaining healthy animals of the replacement heifer herd and 40% (75% in adult sheep and 4% in lambs) in the in-contact sheep flock 77 days after onset of CS in the index case. This episode suggests that, in addition to the common and well recognized acute form of MCF in cattle, this viral infection encompasses a disease spectrum that includes chronic disease and partial to "complete" clinical recovery, and in recovered animals chronic obliterative arteriopathy is the preeminent lesion.

Alcohol and the physiological detection of deception: arousal and memory influences

Eighty male volunteers participated in an analogue study of the effects of alcohol intoxication at the time of a crime on the physiological detection of deception using control question and guilty knowledge techniques. Sixty-four of the subjects committed a mock crime and half of these were intoxicated during the crime. Sixteen subjects committed no crime and served as innocent controls. We found that intoxication at the time of the crime had no significant effect on polygraph test outcomes, although it did affect anticipatory arousal before the crime and subsequent memory for crime details. Manipulations designed to influence memory for crime details and arousal during the crime had differential effects for the two polygraph tests. On the guilty knowledge test, primed subjects who rehearsed specific details following the crime were more detectable than unprimed subjects. On the control question test, primed subjects were also more detectable, but only when arousal during the crime was high.

Ultrastructural pathology of an inherited lower motor neuron disease of pigs

The ultrastructural features of a recently described inherited lower motor neuron disease were studied in 5 affected pigs. Clinical signs comprised progressive ataxia and paresis of variable severity. Affected pigs, 6, 7, 15, 15, and 19 weeks of age, and 2 unrelated healthy pigs, 9 and 15 weeks of age, were anesthetized and their tissues were fixed by whole body perfusion with mixed aldehydes. From 1 or more affected pigs, samples of cervical and lumbar spinal ventral horn, lateral and ventral spinal columns, dorsal and ventral lumbar spinal nerve roots, 2 peripheral nerves (Nn. phrenicus and fibularis communis), and 2 skeletal muscles (Mm. diaphragma and tibialis cranialis) were examined ultrastructurally. There was widespread degeneration of myelinated axons in peripheral nerves and in lateral and ventral columns of lumbar and cervical segments of spinal cord. Axonal degeneration was present in ventral spinal nerve roots and was absent in dorsal spinal nerve roots sampled at the same lumbar levels. Unmyelinated axons in peripheral nerves and spinal nerve roots were unaffected. In 4 of 5 affected pigs, there were atrophic alpha motor neurons in cervical spinal cord that contained dense, round osmiophilic perikaryal inclusions up to 4 microns in diameter and round swollen mitochondria. Axonal regeneration was present in N. phrenicus of the 19-week-old affected pig that had clinical signs of longest duration (10 weeks). There was no morphologic evidence of axonal degeneration or spinal neuronal atrophy in either control pig. The ultrastructural features of this motor neuron disease distinguish it from other reported progressive spinal neuropathies of pigs.

An inherited lower motor neuron disease of pigs: clinical signs in two litters and pathology of an affected pig

A chronic progressive neurodegeneration, called hereditary porcine neuronal system degeneration (HPNSD), was recognized in a swine herd in Devon, England. Adult pigs that were presumed carriers of the dominantly inherited trait for HPNSD were transferred from England, where a breeding colony was maintained for 9 years, to the Wyoming State Veterinary Laboratory (WSVL) for study. Two litters of affected piglets were born to 2 carrier sows at the WSVL. Clinical signs of muscular tremors, paresis, or ataxia developed at 12-59 days of age in 4 of 6 liveborn pigs. Three other pigs were stillborn. In the 4 affected liveborn pigs, clinical signs progressed and included symmetrical (3 pigs) or asymmetrical (1 pig) posterior paresis, bilateral knuckling of metatarsal-phalangeal or carpal joints, poor exercise tolerance, and in 1 pig, marked hind limb hypermetria. A 34-kg gilt exhibiting clinical signs of muscular tremors and posterior paresis and clinical signs for 22 days was euthanized and examined postmortem at 83 days of age. Apart from decubitus ulcers, gross lesions were absent. Microscopically, perikaryal vacuolation and osmiophilic lipid droplets were observed in atrophic alpha motor neurons in the spinal cord. There was axonal (Wallerian) degeneration in sulcomarginal and dorsal spinocerebellar tracts. Axonal degeneration also involved ventral but not dorsal spinal nerve roots, and was present in eight peripheral nerves sampled for histopathology. Changes in skeletal muscles were consistent with denervation atrophy and were most pronounced in M. tibialis cranialis of the 6 muscles sampled. Immunohistochemical staining of spinal cord for phosphorylated and nonphosphorylated neurofilaments did not reveal abnormal patterns, unlike some well-characterized inherited motor neuron diseases in other species.

Immunohistochemistry of parasitic subepidermal vesiculobullous disease in American badgers (Taxidea taxus)

Some populations of free-ranging American badgers (Taxidea taxus) develop a distinctive seasonal dermatitis due to the subcutaneous filariid Filaria taxideae. Subepidermal vesicles that contain filarial ova develop in thinly haired skin of the inguinal area, proximal thigh, and ventral abdomen. The purpose of this study was to establish by immunohistochemistry whether basement membrane components colocalized with the roof or floor of vesicles and to confirm that filarial ova occur in intradermal vessels. Samples of skin with characteristic F. taxideae-induced subepidermal vesicles were collected from 10 adult male (n = 8) and female (n = 2) badgers. Samples were fixed in formalin for 1-4 days and processed routinely into paraffin wax. Immunohistochemical staining for basement membrane was attempted with anti-collagen IV antibodies (AM168-5M, AR079-5R, AB748) and antilaminin antibodies (MA078-5C, AR078-5R, L-9393). Optimal results in skin from badgers were obtained using a biotin-streptavidin technique and AR079-5R (anti-human collagen IV) and AR078-5R (anti-murine laminin). There was positive staining of the floor of vesicles in 5 of 6 badgers tested with antibodies to laminin and collagen IV. In 5/10 badgers, filarial ova and first stage F. taxideae larvae were found in dilated vascular channels of the upper dermis, and these vessels stained positively for factor VIII-related antigen. The results suggest that F. taxideae-induced subepidermal separation occurs consistently in the lamina lucida portion of the basal lamina and that filarial ova occur in dermal vessels.

Buccal prochlorperazine as an antiemetic for day care surgery

This study compares the antiemetic effect of prochlorperazine in a buccal preparation with a control group as a preoperatively administered antiemetic. Fifty-two female day care patients undergoing gynaecological surgery or breast biopsy were studied. Patients were randomly allocated to two groups. Patients in group one received no antiemetic, while those in group two received 6mg buccal prochlorperazine one hour before surgery. Nausea was assessed with a visual nausea scoring system and interview similar to those used in previous series. Assessment times were before surgery and at one, four and 24 hours after surgery. Patient demographics and type of surgery were similar for the groups. The incidence of postoperative nausea and vomiting for the groups one and two was 57.7% and 15.4% respectively, p < 0.05. Most of the patients who experienced nausea in group one and two (86.7% and 50%) gave it a score less than five, indicating mild nausea. The majority of patients did not require treatment for postoperative nausea. The postoperative antiemetic and narcotic requirements were similar in the two groups. This study demonstrates that prochlorperazine at the dose used is effective in preventing postoperative nausea in the patient population studied.

Pathology of renal dysplasia and bladder aplasia-hypoplasia in a flock of sheep

Congenital renal disease was detected in a flock of sheep in the English Midlands over 2 successive years (1982 and 1983). A Suffolk ram was removed from the flock and test mated to unrelated Suffolk ewes in another flock; 14 of the resulting 43 lambs born in 1984 had an identical congenital renal disease. Kidneys were examined microscopically from 60 clinically affected neonatal lambs. Kidneys from 7 of the 60 clinically affected neonatal lambs (1, 1983; 6, 1984) were examined ultrastructurally and compared with kidneys from 3 healthy unrelated neonatal lambs. Most affected lambs examined (52/60) had bilaterally small kidneys (< or = 2 g) with fine intracortical cysts and distinct cortical and medullary zones. Kidneys were either grossly normal (3/60 lambs) or multicystic and of normal size to markedly enlarged (5/60 lambs). The bladder was absent or vestigial in most lambs. Microscopically, poorly differentiated ("primitive") tubules were present in renal cortex and medulla. Proximal convoluted tubules, where present, were formed by epithelial cells with distinctive round weakly autofluorescent intracytoplasmic inclusions with the ultrastructural appearance of atypical lysosomes. Loops of Henle, distal convoluted tubules, and juxtaglomerular-peripolar cell complexes were largely absent. Glomerular changes were minimal. Cystic dilatation of nephrons was restricted to proximal convoluted tubules lined by vacuolated epithelium. This distinctive congenital renal dysplasia of sheep was most likely inherited as a dominant trait with complete penetrance.

Subepidermal vesiculobullous filarial dermatitis in free-ranging American badgers (Taxidea taxus)

Skin and superficial lymph nodes from the 65 juvenile (< 1 year old) and adult free-ranging American badgers (Taxidea taxus) of both sexes that were killed from late July to late October 1991 as part of the recovery program for the endangered black-footed ferret (Mustela nigripes) were examined for evidence of Filaria taxideae. Fifty-one badgers (51/64, 80%) were infected. Both adult badgers (30/32, 94%) and juvenile badgers (21/32, 67%) were infected by adult filarial worms, which occurred most commonly in subcutaneous tissues of the inguinal area, proximal thigh, and ventral abdomen. Sections of formalin-fixed skin and, from many badgers, subcutaneous lymph nodes were stained with hematoxylin and eosin, Jones' methenamine silver (for basement membrane), and an avidin biotin peroxidase complex method (for factor VIII-related antigen). Superficial dermatitis attributable to embryonated filarial ova and larvae was present in 26/64 badgers (41%), all of them adult (> 1 year old). Acute lesions consisted of multifocal vesiculobullous dermoepidermal separation and superficial perivascular dermatitis. Ultrastructural examination and Jones' silver-stained sections revealed separation between basal keratinocytes and the basal lamina (subepidermal vesiculation). Older lesions consisted of ulcerative superficial granulomatous dermatitis associated with ova and larvae. Multifocal granulomatous endolymphangitis, which involved afferent lymphatics of subcutaneous lymph nodes, was associated with viable as well as degenerative ova and larvae. Adult filarial worms were found in the subcutis alone and did not provoke an inflammatory reaction.

Ovine myeloencephalitis-leukomyelomalacia associated with a Sarcocystis-like protozoan

Bilateral pelvic limb paresis developed in 7 of 15 10-month-old Blueface Leicester ram lambs on a mixed enterprise farm in the North of England. Clinical signs were principally mild to severe paresis of the pelvic limbs. Two mildly affected lambs recovered. Multifocal spinal cord white matter edema and necrosis, glial nodules, and mild to moderate nonsuppurative encephalomyelitis were the principal findings in 3 severely paretic lambs examined histologically. Protozoan bodies (12.7-23.0 microns) that stained immunocytochemically for Sarcocystis epitopes were in spinal cord glial cells of 2 of 3 lambs. Protozoa did not react immunocytochemically with anti-Toxoplasma gondii or Neospora canium antisera. Serology indicated there was recent exposure to Sarcocystis spp. in some surviving lambs. These cases resembled those in previous reports of paresis due to an unidentified Sarcocystis-like protozoan in sheep (ovine protozoan myeloencephalitis) in the British Isles, the USA, France, Australia, and New Zealand.

Naturally occurring selenosis in Wyoming

A review of Wyoming State Veterinary Laboratory records for 1947-1987 revealed no substantiated cases of naturally occurring selenosis. However, older reports attributed thousands of animal deaths to selenium each year in this area. Beginning in August 1988, cases of suspected selenosis and selenium deficiency were solicited from veterinarians and producers by announcements in various statewide livestock publications. As of August 1991, 4 cases (all horses) of naturally occurring selenosis have been confirmed. Clinical signs were most often referable to epithelial damage, e.g., hoof lesions and loss of mane and tail. None involved neurologic signs. Sources of selenium included native range and grass hay.

Sudden acquired retinal degeneration ('silent retina syndrome') in two dogs

Two unrelated adult dogs developed idiopathic, acute-onset, bilateral total blindness. The ophthalmoscopic changes were minimal and no electroretinographic response could be detected in either dog. The retinas were examined ultrastructurally 10 days (dog 1) and two-and-a-half months (dog 2) after they became blind. There was widespread loss of the outer segments of rod and cone photoreceptors. Where the outer segments persisted, there was marked tubulovesicular change with loss of normal orientation in their lamellae. Second order neurons (bipolar cells) and ganglion cells were unaffected. The cause of this selective and massive disruption of rod and cone endings was not established, but acute toxicity is proposed as a possible mechanism.

The microbial flora of in-use blood pressure cuffs

The capacity of blood pressure cuffs to act as vehicles of hospital infection has been recognised. We describe the microbial flora of in-use DINAMAP blood pressure cuffs used in the operating theatres and one recovery room in a teaching hospital. Our results show significant microbial contamination of in-use blood pressure cuffs.

Pathogenicity of experimental infection with 'pneumotropic' porcine coronavirus

Virus localisation and lesions were studied in 14 one-week-old piglets following combined intranasal-oral inoculation with a British isolate of ‘pneumotropic’ porcine coronavirus (pcv) and were compared with the effects of transmissible gastroenteritis virus (tgev) infection in five piglets. Unlike TGEV-infected piglets, all pcv-inoculated piglets remained clinically healthy. Seroconversion was detected at seven days after inoculation. Mild bronchointerstitial pneumonia involving terminal airways was consistently present at two days after infection and thereafter. Both pcv and tgev infected bronchiolar epithelium and alveolar macrophages but, unlike tgev, replication by pcv in villous enterocytes was limited and did not cause villous atrophy.

Pathogenicity of experimental infection with 'pneumotropic' porcine coronavirus

Virus localisation and lesions were studied in 14-one-week-old piglets following combined intranasal-oral inoculation with a British isolate of 'pneumotropic' porcine coronavirus (PCV) and were compared with the effects of transmissible gastroenteritis virus (TGEV) infection in five piglets. Unlike TGEV-infected piglets, all PCV-inoculated piglets remained clinically healthy. Seroconversion was detected at seven days after inoculation. Mild bronchointerstitial pneumonia involving terminal airways was consistently present at two days after infection and thereafter. Both PCV and TGEV infected bronchiolar epithelium and alveolar macrophages but, unlike TGEV, replication by PCV in villous enterocytes was limited and did not cause villous atrophy.

Radial and tibial nerve pathology of two lactating ewes with "kangaroo gait"

Radial and tibial nerves of two ewes with clinical signs of chronic "kangaroo gait" were examined by qualitative and quantitative techniques and compared to the same nerves of a clinically normal ewe in late lactation. In affected ewes, there was extensive axonal degeneration of myelinated fibres in the radial nerve. Large and small myelinated fibres were affected equally and unmyelinated fibres were normal. Nerve fibre regeneration was present. In contrast, tibial nerve changes in the "kangaroo gait" ewes were minimal. The chronic nature of the radial nerve pathology was consistent with the clinical time course of "kangaroo gait". Regeneration may account for gradual improvement with eventual recovery in most chronically affected ewes. An episode of bilateral severe compression of a proximal radial nerve site is proposed as an explanation for the neuropathy, although the specific mechanism of this trauma is not known.

Interscalene brachial plexus blockade with lidocaine in chronic renal failure--a pharmacokinetic study

Plasma lidocaine concentrations, latency of onset, and duration of anaesthesia, were determined after interscalene brachial plexus block in 16 patients presenting for elective upper limb surgery. Eight patients had normal renal function and eight had chronic renal failure, as determined by creatinine clearance. Significantly higher plasma lidocaine levels were recorded ten minutes after infiltration in patients with chronic renal failure (p less than 0.05). Cmax plasma levels for normal patients (5.6 +/- 1.1 micrograms.ml-1) and for patients with chronic renal failure (6.6 +/- 1.6 micrograms.ml-1) were not significantly different. The latency of onset and duration of anaesthesia were similar in both groups. One per cent lidocaine solution may be administered to patients with normal and impaired renal function to provide effective brachial plexus blockade for short surgical procedures.

Chronic myofascial pain: management by low-output helium-neon laser therapy

Therapeutic benefits of low-output helium-neon laser therapy have not been established, but laser therapy has been suggested as an effective means of treating many acute and chronic musculoskeletal pain syndromes. Although not released for general clinical use by the FA, the helium-neon laser has been promoted to physical therapists and athletic trainers as potentially useful for the treatment of pain syndromes. In particular, it has been proposed that it may be more effective than conventional measures such as medication and conventional physical therapy in the treatment of myofascial pain syndromes (fibrositis, fibromyalgia). The citations in the literature include only case reports. Sixty-two patients were treated by using acupuncture points. Two sessions of five treatments were given six weeks apart. A crossover double-blind technique was used in the treatments. The clinical responses were assessed using portions of the McGill Pain Questionnaire. No statistical difference between the treatment and the placebo groups could be determined.

A genetic, pathological and virological study of congenital hypotrichosis and incisor anodontia in cattle

Two Friesian cows, half-sibs by a common dam, produced four bull calves with severe congenital hypotrichosis and incisor anodontia and three normal heifers by six unrelated Holstein, Friesian, Devon and Hereford bulls. The two dams, and their dam, had coats of a short, stubbly nature and the pigmented areas appeared rusty grey rather than black. Pathological examination of skin samples taken from multiple standardised sites from two of the affected calves showed a reduction in the number of large first-formed hair follicles. Smaller calibre hair follicles were present but, unlike those of normal neonatal calves, all were in the telogen (inactive) phase. Although the herd was infected with bovine virus diarrhoea virus there was no convincing evidence that the virus was implicated in the pathogenesis of these cases of congenital hypotrichosis with incisor anodontia. The family breeding information on the few severely affected and normal progeny and mildly affected and normal parents may be explained by the genetic hypothesis of an X-linked incompletely dominant gene.

Immunocytochemistry of ovine sporozoan encephalitis and encephalomyelitis

An indirect immunoperoxidase procedure was developed to detect Sarcocystis spp meronts in paraffin wax sections of infected ovine tissues. Ten rabbits seronegative to Sarcocystis spp and Toxoplasma gondii were injected intradermally or subcutaneously over 2 months with varying quantities (150 to 750 micrograms) of purified soluble cystozoite antigen derived from ovine heart microcysts. Serum from each rabbit was tested against paraffin wax preparations of S. ovicanis cysts, second generation S. ovicanis meronts and T. gondii cysts. Sera from three rabbits reacted with S. ovicanis meronts without any cross reaction to T. gondii antigens. Toxoplasma gondii and Sarcocystis spp-specific sera were used to identify the sporozoa in six cases of naturally-occurring ovine encephalitis or encephalomyelitis. Sarcocystosis was diagnosed in four lambs and toxoplasmosis in one lamb. The generic identity of the sporozoan in the sixth case was not established as meronts reacted with both Sarcocystis spp- and T. gondii-specific sera. The study demonstrates the value of the immunohistological technique of visualizing sparsely distributed meronts in naturally-infected tissues and shows that sporozoa of the genus Sarcocystis and T. gondii, and possibly also sporozoa the identity of which is as yet unclear, are associated with encephalitis of sheep in Britain.

Congenital sporozoan encephalomyelitis in a calf

Protozoan encephalomyelitis was diagnosed post mortem in a five-day-old Friesian calf which had shown nervous signs from birth. The lesion was a subacute necrotising multifocal encephalomyelitis associated with protozoan bodies (6 X 6 microns to 16 X 30 microns). Ultrastructurally these bodies corresponded to apicomplexan meronts composed of eight to 89 merozoites which reproduced by internal budding to form paired daughter cells (endodyogeny). The merozoites were indistinguishable from Toxoplasma gondii; they reacted weakly with anti-Sarcocystis species serum and did not cross react with anti-T gondii serum. The generic identity of the sporozoan was not established, but it is unlikely to have been either Sarcocystis species or T gondii.

Experimental ovine sarcocystosis: sequential ultrastructural pathology in skeletal muscle

Six lambs inoculated with 70,000 Sarcocystis oocysts were killed at 14, 25, 33, 42, 60 and 81 days post-inoculation (pi). Tissue changes and developing cysts in one muscle (left M. semimembranosus) were studied by transmission electron microscopy. Perivascular macrophages contained intracytoplasmic merozoites at 25 and 33 days pi. Cysts with metrocytes were established at 42 days pi, at which time cyst wall zones were simple without surface projections. At 60 days pi, cysts contained metrocytes, some in division, and immature cystozoites. Cylindrical cyst surface projections were 1.55 microgram tall, 0.45 microgram wide and had specialized tip and base zones. Cysts at 81 days pi contained metrocytes and mature cystozoites. Cyst surface projections had a regular association with mitochondria of the parasitized myocyte. A mild or moderate myositis developed during both meront (25 to 33 days pi) and cyst-forming (42 to 81 days pi) stages. Initially histiocytic, the exudate eventually consisted of plasma cells and macrophages. A small minority of parasitized myocytes attracted a local inflammatory reaction. Following macrophage invasion of the sarcoplasm, the cyst wall zone degenerated and underwent phagocytosis and cystozoites became pyknotic. With advanced cyst degeneration there was local destruction of the host muscle fibre.

Experimental microcyst sarcocystis infection in lambs: pathology

Six 34- to 42-day-old lambs raised in coccidia-free conditions were inoculated with 70,000 sporocysts derived from sheep heart with microscopic sarcocysts. Fever and mild anorexia occurred between 25 and 33 days after inoculation. A transient anaemia was most marked 32 days after inoculation. Lambs were killed and examined 14, 25, 33, 42, 60 and 81 days after inoculation. Gross lesions were absent. First and second generation meronts were present in endothelial cells at 25 and 33 days after inoculation. Meronts were most numerous in kidney glomeruli. Developing sarcocysts were rare at 42 days after inoculation. Sarcocysts with a primary cyst wall 2 to 3 micron thick composed of palisade projections were common at 60 and 81 days after inoculation in striated muscle and brain. Mild to severe striated muscle myositis and non-suppurative encephalitis or encephalomyelitis with glial nodules were observed 25 to 81 days after inoculation. Sarcocyst frequency varied considerably; it was highest in myocardium, M vastus intermedius, M vastus medialis, M extensor carpi radialis and tongue muscle and was lowest in M masseter.

Retinal dysplasia of English springer spaniel dogs: light microscopy of the postnatal lesions

The histologic features of retinal dysplasia were studied in 26 English springer spaniel dogs of one day to four years of age. Dysplastic lesions in neonatal pups occurred predominantly in the peripapillary tapetal area of sensory retina. They consisted of complex linear folds and rosettes which were composed of hyperplastic neuroblasts. Dysplasia usually was not associated with incomplete differentiation of the outer neuroblastic layer. The outer limiting membrane was absent locally and numerous patent subretinal capillaries existed in the region of folds. The dysplastic features may be related to aberrant development of Muller cells and of retinal capillaries. In adolescent dogs, dysplastic lesions were less complex and usually were not accompanied by aberrant capillaries. Focal or complete retinal separation was present in some adolescent dogs. In adult dogs, features of retinal atrophy were found within dysplastic areas. No significant histologic lesions were found in the extraocular tissues of 12 affected dogs which were surveyed extensively.