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[Orthotopic liver transplantation in miniature pigs: some technical considerations in recipient].

We compared temporary aortic occlusion technique (TAO) with venous bypass in anhepatic phase of the recipient in the liver transplants in miniature pig, using cuff technique in connecting the portal vein and/or the inferior vena cava. Twenty four hour survival rate after liver transplant by TAO in anhepatic phase was almost the same as that by venous bypass. There was no difference in the posttransplant changes of serum transaminase and coagulating factors between the two groups above. Profound hypotension and metabolic acidosis were encountered on the release of occluded aorta. Rapid blood transfusion and fluid infusion were necessary with the administration of bicarbonate to keep the blood pressure constant. Though we had to take special care to stabilize the general condition during the operation, the operation technique with TAO was quite simple. The hemodynamic state of the venous bypass group was also stable, but the operation was more complex and troublesome. Cuff technique was useful in connecting veins and recipients' survival rate with cuff technique was better than that with suturing method but the anastomosis by cuff technique always resulted in chronic stenosis and our new method, temporary cuff technique, was effective to prevent chronic stenosis.

Animals↗

Bone marrow transplantation in miniature swine. III. Graft-versus-host disease and the effect of T cell depletion of marrow.

Graft-versus-host disease (GVHD) has been evaluated in partially inbred miniature swine in order to study this complication of allogeneic bone marrow transplantation (BMT) in a major histocompatibility complex (MHC) genetically defined large animal model. Bone marrow from MHC homozygous ("parental") swine was injected into irradiated (900 rads total-body irradiation) MHC heterozygous ("F1") swine that shared one haplotype with the donor. All 18 animals successfully engrafted with donor bone marrow, and 17 of these developed skin rash of varying intensity depending on the extent of T cell depletion of infused marrow. Of 18 animals, 8 received undepleted bone marrow from exsanguinated donors and 2 also received additional peripheral blood lymphocytes (PBL) as a source of mature T cells. All 8 showed a moderate-to-severe rash, and the 2 pigs that received additional donor PBL developed the most severe rash. The cutaneous eruption seen in this model clinically, histologically, and immunologically resembled human GVHD. Two protocols of T cell depletion of donor bone marrow by antiporcine T cell monoclonal antibodies plus complement were tested for their effect on development of GVHD. The combination of two monoclonal antibodies, 74-12-4 (PT4) and 76-2-11 (PT8), had a marginal effect on the subsequent development of cutaneous manifestations of GVHD. However, treatment of the donor marrow by a combination of three monoclonal antibodies--PT4, PT8, and MSA4 (PT11)--effectively decreased the severity of the GVHD skin rash. These results indicate that (1) the GVHD associated with allogeneic bone marrow transplantation in swine is dependent on T cells in the marrow; (2) effective T cell depletion of donor marrow by monoclonal antibodies and complement does not prevent engraftment; and (3) this swine GVHD model, which allows study with F1 and homozygous parental combinations in an MHC genetically defined large animal, is particularly useful for the understanding of GVHD pathogenesis, prevention, and treatment.

Animals↗

[Quantitative estimation of synaptic acetylcholinesterase inhibition with galanthamine using parameters of miniature endplate currents].

Miniature end-plate currents (MEPC) were recorded in voltage clamped muscle fibers of the rat diaphragm at different degrees of acetylcholinesterase (AChE) inhibition with galanthamine. A model has been suggested connecting the increase in MEPC amplitude with the concentration of a competitive reversible AChE inhibitor. Using the model suggested, the changes in the junctional AChE activity inhibited with different concentrations of galanthamine were estimated. The calculated value of the inhibitory galanthamine constant is 2.8 X 10(-7) M.

Acetylcholinesterase↗

Factor XII deficiency and von Willebrand's disease in a family of miniature poodle dogs.

The simultaneous occurrence of factor XII deficiency and von Willebrand's disease (VWD) is described in a family of Miniature Poodles affected concurrently with a familial non-spherocytic hemolytic anemia. Although there was a dominant distribution of factor XII deficiency in this family of dogs, only the dogs suffering from non-spherocytic hemolytic anemia had concurrent VWD gene expression. Neither the factor XII deficient dogs nor the VWD carrier dogs displayed bleeding tendencies.

Animals↗

A miniaturized cell-mediated cytotoxicity assay with human effector mononuclear cells.

A miniaturized method (Microtest, MIT) for detecting natural killer (NK) and antigen-elicited cell-mediated cytotoxicity has been developed. It retains the sensitivity and the efficiency of conventional macroassay (Macrotest, MAT). In comparison with the standard MAT, MIT provides a 5-fold reduction in the number of effector and target cells without changing the final reaction volume. This avoids the excessive relative evaporation that could occur in microassays employing limited reaction volumes. Moreover the use of V-bottom microtiter plates allows the recovery of 0.15 ml of supernatant, thus increasing the efficiency of 51Cr recovery. MIT was adopted for the evaluation of the NK activity of untreated or interferon (IFN)-treated human mononuclear cells (MNC) and for cold-inhibition and cytotoxic T-lymphocyte (CTL) assays. In the experiments performed with both macro and micro assays, comparable values of the percentage of specific lysis and of the number of lytic units were found. The slopes of the curves obtained with MIT are generally slightly lower than those detectable with MAT. The Pearson coefficient r2 is generally better for the macroassay although it can be considered acceptable in the microassay. The MIT described here appears to be a useful method, especially for providing information on natural resistance and cytotoxic T-lymphocyte systems in a number of pathological conditions characterized by a small recovery of effector cells from standard blood collection for analytical purposes.

Cell Line↗

Identification of Mycobacterium bovis, using miniaturized thin-layer chromatography and morphologic characteristics.

Lipid analysis was performed on 204 isolates of mycobacteria, using miniaturized thin-layer chromatography (MTLC). A previously described lipid component was found in 92 (96.8%) of 95 isolates of Mycobacterium bovis and in 2 (1.8%) of 109 isolates of other mycobacteria. Using MTLC, an isolate could be identified as M bovis 3 to 4 weeks earlier than by use of conventional biochemical techniques. Examination of isolates for colonial and cellular morphologic characteristics was a useful adjunct in the identification of M bovis by use of MTLC.

Animals↗

[Nonspecific resistance in germ-free and E. coli monocontaminated miniature piglets].

Phagocytic activity of leukocytes, as well as the complement, properdin, and lysozyme levels in the blood serum of miniature piglets, germfree and monocontaminated with E. coli 055 and E. coli 083, were studied. E. coli 055 phagocytosis was decreased in the presence of autologous serum and complement and increased under the effect of specific opsonins (antibodies to E. coli 055). Complement, properdin, and lysozyme levels were decreased in the germfree, in comparison with conventional animals. In the E. coli contaminated piglets properdin and complement production was stimulated most, and lysozyme formation--less. No antibodies to E. coli 055 were revealed in monocontaminated piglets. The highest lysozyme levels were found in the ex-germfree animals, this indicating the participation of factors other than E. coli contamination in lysozyme stimulation. It is concluded that microbial contamination played an important role in the development of cellular and humoral factors of the organism resistance.

Animals↗

Arthrodesis of the scapulohumeral joint in a miniature horse.

Scapulohumeral arthrodesis was performed successfully as treatment for severe degenerative arthritis in a 62-kg miniature horse. Using an approach similar to that used for a dog, this horse's scapulohumeral joint was opened, the cartilage was removed, and the site was stabilized, using an 11-hole narrow dynamic compression plate. Fusion was uncomplicated. The stallion became a successful pasture-breeding animal.

Animals↗

Miniature thermoluminescent dosimeter absorbed dose measurements in tumor phantom models.

Miniature teflon-imbedded CaSO4:Dy thermoluminescent dosimeter(s) (TLD) have been sized and cut to fit inside a syringe needle. These dosimeters have been shown to be linear in response to beta and high energy gamma radiation. This allows for their direct implantation into tumor-bearing animals undergoing radioimmunotherapy and subsequent measurement of dose deposition on a per organ basis. In order to perform these radiolabeled antibody dose measurements with sufficient accuracy, static calibration data must first be generated. Consequently, phantom models were constructed with artificial tumors of diameters ranging from 3-30 mm contained in a surrounding tissue equivalent medium. The TLD were used to characterize dose distributions in a radial direction from the center of the cylindrical tumor volumes containing 131I, 32P, or 90Y radionuclides. Absorbed dose measurements in the boundary region between tumor and outer medium were found to be dependent on the: tumor specific activity, average range of the beta radiation, and radial tumor dimensions.

Antibodies, Monoclonal↗

Continuous intravenous insulin therapy with a miniaturized open-loop system.

For the continuous intravenous application of insulin, a portable open-loop system was developed consisting of a delivery unit with a miniaturized pump and an insulin reservoir which is connected with an electronic control unit. The infusion rates were either preprogrammed or patient-controlled. Blood glucose control with both systems was tested in eight juvenile-type diabetics, among them two of the brittle type. Diabetic control during a 1-2-day pre-infusion period was compared with 2-3 days of continuous insulin infusion; as judged by the mean blood glucose value (MBG), the mean amplitude of glycemic excursions (MAGE), and glucosuria, all patients were significantly better controlled by the open-loop systems than by conventional therapy with subcutaneous insulin. The use of portable open-loop systems offers a promising approach to an improvement of metabolic control in insulin-requiring diabetics.

Adult↗

Technological problems of miniaturized insulin dosing devices and some approaches to clinical trials.

With the long-term goal of developing implantable insulin dosing devices, we have since 1971 developed various types of programme-controlled units for clinical research. In the initial stage, a 24-hour, fixed-programme bed-side device has been in clinical use since 1973. The good results with even labile diabetics has supplied the basis for the further development of sensorless units. Via intermediate stages, two types of miniaturized portable devices were constructed: fixed-programme and demand-programme devices. The essential equipment components have been optimized with a view to later implantability: hermetically sealed capsule for the dosing device, refilling membrane for the insulin reservoir, bubble-free drawing off of the insulin via a wick from a collapsible silicone reservoir, the stepping motor-driven roller pump of approx. 9 cm3 volume, an energy consumption of about 50 mu W, and electronic safety and alarm circuits. Because of stability problems of the insulin, the neutral insulin U-1000 used initially was changed to acid insulin U-100 (both from Hoechst).

Animals↗

Degenerative myelopathy in an adult miniature poodle.

Degenerative myelopathy was diagnosed at necropsy of an adult Miniature Poodle with a 33-month history of progressive pelvic limb ataxia and proprioceptive deficit. Microscopic examination of the cord revealed diffuse degenerative myelopathy. Degenerative myelopathy is usually seen in adult, large-breed dogs and progresses over a period of months. In this case, the myelopathy progressed slowly and the degree of paralysis became more extensive than usually seen.

Animals↗

Effect of laser photocoagulation on oxygenation of the retina in miniature pigs.

A large area of the posterior pole of the retina of the miniature pig was photocoagulated, and 2-3 wk later the PO2 in the preretinal vitreous was mapped with O2-sensitive microelectrodes. In the control retina, the PO2 was highly heterogeneous being much higher close to an artery than opposite an intervascular zone. After photocoagulation, PO2 opposite an intervascular zone was found to be significantly increased. A quantitative histologic analysis showed that in the photocoagulated areas more than 28% of the outer retina was destroyed. The authors conclude from these results that photocoagulation, by partially destroying the pigment epithelium-photoreceptor complex, causes an increase of the oxygenation of the retina.

Animals↗

Development of a miniaturized, improved nucleic acid precursor incorporation assay for chemosensitivity testing of human solid tumors.

Two technological problems limit the usefulness of chemosensitivity assays: low success rates (generally 30-60%); and the requirement for large numbers of tumor cells (5 X 10(5)/dish). To solve these problems, we developed a miniaturized, improved, nucleic acid precursor incorporation assay (MINI-assay). In this new assay, 0.3-1.5 X 10(5) tumor cells were plated in double-layer agarose in 16-mm wells of a Costar (No. 3524) 24-well cluster dish. After 72 h of incubation, 5 microCi [3H]thymidine were added to each well. After an additional 24 h of incubation, the trichloroacetic acid-precipitable material was collected and counted by liquid scintillation. We found that 280 of 351 (80%) human solid tumors gave evaluable chemosensitivity results. Labeling efficiency was optimum when the plating density was between 1.5 and 3 X 10(4) cells/well. Radioisotope uptake was less efficient in 35-mm Petri dishes and in the 7-mm wells. The MINI-assay was particularly suitable for small specimens (less than 1 g) and for tumor types that usually yield small numbers of viable tumor cells (19 of 30 breast cancers and 56 of 71 sarcomas were evaluable). The artifacts of colony counting (cell clumps, debris, clots) were also eliminated with this assay. With high evaluability rates, the requirement of fewer cells, a short duration (5 days), and ease of quantitation, the MINI-assay is widely applicable to chemosensitivity testing in human tumors.

Agar↗

The electrocardiogram of conventional and miniature swine (Sus scrofa).

Standard, augmented limb leads and lead V(10) (representing the Z axis) taken in sequence and three semi-orthogonal leads (I, aVF, and V(10)) taken simultaneously were recorded from 43 healthy pigs. Records were analyzed for rate, rhythm, interval duration and component amplitudes. The wave form of QRS complexes were analyzed in all leads studied. P, QRS, and T vectors were calculated for the mean dorsal (frontal), sagittal, and transverse planes. study of orthogonal leads in right sternal recumbency indicated that ventricular activation is spatially oriented dorsad, sinistrad and slightly caudad. No essential difference was noticed in the conventional and miniature swine. Ventricular fibrillation induced electrically in four older pigs was a progressive, terminal event; in two newborn piglets, ventricular fibrillation induced several times was terminated in each case by spontaneous recovery to sinus rhythm.

Animals↗

Serum biochemical and hematological parameters of Sinclair(S-1) miniature sows during gestation and lactation.

Venous blood samples were collected from 29 Sinclair(S-1) miniature sows at 14, ten, six and two weeks prior to parturition and two, four and six weeks postpartum to determine the effect of pregnancy and lactation upon 19 serum biochemical and 12 hematological parameters. During gestation, the levels of serum cholesterol, blood urea nitrogen and alpha(1)-globulin, as well as packed cell volume and hemoglobin concentration, decreased; whereas, the level of serum beta-globulin increased. During lactation, the concentrations of serum glucose, total protein, albumin, beta-globulin, calcium, sodium and hemoglobin, as well as packed cell volume, decreased; whereas, the concentration of serum cholesterol and the activity of serum alkaline phosphatase increased.

Alkaline Phosphatase↗

[Cross-sectional anatomy of miniature "Shiba" goat].

The anatomical relations of visceral organs and other tissues in the thoracic, abdominal and pelvic cavities of the male miniature "Shiba" goat are illustrated as thirteen semi-diagramatic representations of cross sections.

Animals↗