Renal allograft tolerance in DLA-identical and haploidentical dogs after nonmyeloablative conditioning and transient immunosuppression with cyclosporine and mycophenolate mofetil.

BACKGROUND: Canine models of bone marrow and renal transplantation have provided important preclinical data relevant to developing novel therapeutic protocols for hematopoietic and solid organ transplantation in human beings. Nonmyeloablative transplantation has been shown to induce stable mixed hematopoietic chimerism in normal dogs and correct the phenotype of canine pyruvate kinase deficiency and Glanzman's thrombasthenia. In this study, we investigated the potential for inducing renal allograft tolerance using a nonmyeloablative bone marrow transplantation strategy that induces mixed chimerism in DLA-identical dogs. METHODS: Reciprocal renal allografts were performed in 4 DLA-identical and 4 DLA-haploidentical dogs with nonmyeloablative conditioning (200 cGy total body irradiation [TBI]) and transient immunosuppression with cyclosporine (CSP) and mycophenolate mofetil (MMF) with and without simultaneous bone marrow transplantation. Two DLA-identical control dogs received reciprocal renal allografts without TBI or immunosuppression with CSP and MMF. Serum creatinine (Cr) concentration was monitored to assess renal allograft function. RESULTS: The renal allografts were acutely rejected in the 2 DLA-identical dogs without TBI or immunosuppression. There was long-term (>1 year) renal allograft survival as evidenced by a normal (<2.0 mg/dL) serum Cr concentration in both the DLA-identical and DLA-haploidentical dogs that underwent 200 cGy TBI and transient immunosuppression with CSP and MMF either with or without simultaneous bone marrow transplantation. CONCLUSIONS: Nonmyeloablative conditioning (200 cGy TBI) and transient immunosuppression with CSP and MMF induce renal allograft tolerance in DLA-identical and DLA-haploidentical dogs without donor/host mixed hematopoietic chimerism. These findings suggest it may be possible to induce tolerance to solid organ transplants without the need for chronic immunosuppressive therapy or stable hematopoietic chimerism in the setting of both DLA-matched and haploidentical transplants.

Disseminated infection with Phialemonium obovatum in a German shepherd dog.

A 4-year-old spayed female German Shepherd Dog was evaluated because of left forelimb lameness. A fungal granuloma on the distal portion of the radius was determined to be the cause of the lameness; the infecting organism was identified as Phialemonium obovatum. Despite aggressive treatment with amphotericin B, itraconazole, and ketoconazole and curettage of the local area, the dog developed systemic disease and was euthanatized 5 months after initial evaluation. Immune dysfunction may have played a role in development of disseminated disease, because although serum concentrations of total IgG, IgA, and IgM were within or greater than reference ranges, results of lymphocyte proliferation assays were abnormal, which indicated cellular immune dysfunction. Infection with Phialemonium obovatum should be considered as a differential diagnosis when branching fungal organisms are detected during histologic, cytologic, or microbiologic evaluation of tissue specimens.

Identification of the major water/salt insoluble wheat proteins involved in cereal hypersensitivity.

BACKGROUND: Several studies have investigated water/salt soluble proteins which comprise 50% of the proteins in wheat. The remaining 50% of wheat proteins, are water/salt insoluble proteins of which there is limited information on their role in cereal hypersensitivity. OBJECTIVES: To investigate the allergenicity of the water/salt insoluble gliadin and glutenin proteins (prolamins). METHODS: RAST, electrophoresis and Western blotting were used to identify water/salt insoluble wheat allergens. Competitive RAST inhibition was conducted to investigate cross-reactivity between prolamins and water/salt soluble wheat proteins. RESULTS: Specific IgE to alpha-gliadin and to total glutenins were detected in all sera. IgE to beta-, gamma-, fast omega-, and slow omega-gliadin were present in lower numbers of sera. Prolamin allergens of 90-11 kDa were identified by immunoblotting. Water/salt soluble proteins crossreacted with alpha-gliadin and total glutenins. CONCLUSIONS: Individuals who are hypersensitive to water/salt soluble wheat proteins produce specific IgE to water/salt insoluble wheat proteins. Western blotting has shown that gliadins, glutenins and proteins with similar molecular weights as the endogenous water/salt soluble wheat enzyme inhibitors are important allergens. Alpha and fast omega- are the most allergenic gliadins. The water/salt insoluble proteins share cross-reacting epitopes with water/salt soluble proteins. These data show that the numbers of proteins involved in the development of cereal hypersensitivity is greater than previously believed and that the development of specific IgE to alpha-gliadin may in part depend on the presence of cross-reacting antibodies to water/salt soluble flour allergens.

Effect of combined administration of insulin-like growth factor and platelet-derived growth factor on the regeneration of transected and anastomosed sciatic nerve in rats.

OBJECTIVE: To evaluate the efficacy of combined administration of platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF-I) on the regeneration of transected and anastomosed sciatic nerves. ANIMALS: 25 male Lewis rats. PROCEDURE: Transection and anastomosis was performed of the left sciatic nerve of all rats. At the time of surgery, treatment group rats received a combination of PDGF (0.75 microgram) and IGF-I (1.5 micrograms) along with vehicle (2% methyl cellulose gel) at the anastomosis site. Control rats received vehicle alone. Evaluation consisted of motor evoked potentials and nerve conduction velocity, quantitative histologic examination, sciatic functional index, and visual assessment of repair organization (lesion scores). RESULTS: Significant differences in motor evoked potential latency, nerve conduction velocity, axon number, sciatic functional index, or lesion scores were not found between groups. CONCLUSIONS: Combined administration of PDGF and IGF-I did not enhance peripheral nerve regeneration in a transection and anastomosis model as determined 6 weeks after surgery. CLINICAL RELEVANCE: These findings support the assumption that mechanical, versus trophic, effects predominate when nerve ends are closely apposed.

The intraosseous blood supply of the canine radius: implications for healing of distal fractures in small dogs.

The intraosseous vascular anatomy of the radius was studied in 12 pairs of canine cadaver limbs. Six pairs of specimens were obtained from small-breed dogs (less than 6 kg) and six pairs were obtained from large-breed dogs (18 to 30 kg). All specimens were studied after arterial injection with India ink. Samples were fixed, frozen, then sectioned and processed using a modified Spalteholz technique. In all specimens, the intraosseous blood supply arose from the nutrient artery with its associated branches and the metaphyseal arteries. In small-breed dogs, there was decreased vascular density at the distal diaphyseal-metaphyseal junction compared with large-breed dogs. The reduced vascularity corresponded to the region associated with a poor prognosis for fracture healing in small-breed dogs. This regional association suggests that a decreased vascular supply in the distal radius may contribute to a higher frequency of delayed union and nonunion in smaller dogs.

Partial regeneration of the sciatic nerve in rats enhances motor excitability to magnetic stimulation.

Motor-evoked potentials elicited from transcranial magnetic stimulation were recorded from both cranial tibial muscles of 10 Lewis rats. One sciatic nerve was then transected and surgically reanastomosed and allowed to regenerate for 6 weeks. Walking function was tested weekly using a footprint test giving a functional sciatic nerve index. At the end of the study motor-evoked potentials were again performed, as were nerve conduction velocities and supramaximal stimulation of operated and unoperated sciatic nerves. The nerve was evaluated for myelinated axon numbers. Functional sciatic index, numbers of myelinated axons, nerve conduction velocities, and supramaximal stimulation demonstrated the regenerated nerve to be functional, but to a lesser extent than the unoperated nerve. In all cases the amplitude of the compound muscle action potential evoked from transcranial magnetic stimulation of the motor cortex was greater in the operated motor pathway. This finding demonstrates hyperexcitability of the motor pathway to magnetic stimulation during peripheral nerve regeneration.

Peripheral nerve injury.

Inadequate peripheral nerve regeneration as a result of trauma contributes greatly to the morbidity of surgical patients. Animals admitted as an emergency often have concurrent orthopaedic injuries that impair mobility and may mask peripheral nerve dysfunction if a thorough neurological examination is not performed. This article reviews the pertinent anatomy of the peripheral nervous system as well as the degenerative and regenerative responses that occur in traumatized nerves. Physical examination and electrodiagnostic techniques that characterize the extent of nerve impairment are described. The management of peripheral nerve lacerations for open and closed wounds is detailed, as well as the presenting clinical signs and prognosis for brachial plexus avulsions, sciatic nerve damage, and sacrococcygeal injury.

Investigation of possible adverse allergic reactions to mycoprotein ('Quorn').

Mycoprotein ('Quorn') is a food produced for human consumption from Fusarium graminearum. Crossreactivity studies showed that mycoprotein shared multiple common allergenic determinants with Aspergillus fumigatus and Cladosporium herbarum and some with Alternaria alternata. There is, therefore, a potential for mould allergic patients to react adversely to inhaled or ingested mycoprotein. Mycoprotein RAST screening of mycoprotein production workers was made during a 2 year period. Two of the production workers had specific RAST binding > or = 2% but none reported symptoms. Two of 10 patients referred to hospital following vomiting and diarrhoea after ingestion of mycoprotein had a mycoprotein skin-prick test weal > or = 2 mm but none had a significantly raised RAST. These largely negative results are important and reassuring because consumption of the product in the U.K. is now widespread and increasing.

Staff nurses' experiences as co-investigators in a clinical research project.

This article discusses the development of a clinical research project that was initiated by staff nurses and ultimately received funding from the Center for Nursing Research, National Institutes of Health (NIH) in 1988. Staff nurses from a large children's hospital in the midwest generated the clinical question and worked through the maze and mechanics of developing and implementing a team research project in the clinical setting.

Effect of colostrum or medium-chain triglyceride supplementation on the pattern of plasma glucose, non-esterified fatty acids and survival of neonatal pigs.

A total of 48 neonatal pigs were used to determine whether intubation with colostrum or medium-chain triglyceride (MCT) would enhance glucose homeostasis and survival. Pigs were removed from the sow prior to nursing and alloted to three treatment groups. Fasted pigs received only water for 30 h, whereas those allotted to supplemented groups received either 30 ml of colostrum or 15 ml of MCT at 6 and 16 h after birth (t6 and t16). Supplementation with MCT (t6) resulted in a 2.4-fold elevation in plasma non-esterified fatty acid (NEFA) concentration compared with fasted pigs (260 vs 109 microEq/liter at t8; P less than .05). This difference increased following the second MCT dose (436 vs 117 microEq/liter at t18; P less than .05). Colostrum supplementation also elevated plasma NEFA (201 and 259 microEq/liter at t8 and t18, respectively); however, less triglyceride fatty acid was presented via colostrum compared with MCT. Supplementation with MCT resulted in a greater increase in plasma glucose concentration, relative to fasting levels (75 vs 56 mg/ml at t8; 76 vs 62 mg/ml at t18), than was obtained with colostrum (68 and 65 mg/ml at t8 and t18, respectively). Residual effects of supplementation to t30 were evident for both MCT and colostrum pigs in NEFA levels, but only the MCT group had a greater (P less than .05) concentration of plasma glucose at t30 compared with the fasted group (63 vs 49; P less than .05). This regimen of MCT supplementation was employed in an experiment with nursing pigs to determine whether MCT would improve glucose status and survival of less-competitive pigs.(ABSTRACT TRUNCATED AT 250 WORDS)