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At least 631 records · Page 35Linked to original sources
PubMed1979

Cardiovascular function in anesthetized miniature swine.

Miniature swine anesthetized with pentobarbital were studied with respect to their cardiovascular function under control conditions and in response to catecholamines, baroreceptor inhibition, bilateral vagotomy and vagal nerve stimulation. Measurements included aortic pressure, heart rate, intraventricular pressure and its maximum rate of rise during contraction, carotid blood flow and resistance, femoral blood flow and resistance, and renal blood flow and resistance. The cardiovascular actions of norepinephrine, epiniphrine and isoproterenol were similar to those in other mammals, and the adrenergic receptor mechanisms also were susceptible to blockade with phentolamine or propranolol. Inhibition of the carotid baroreceptors was accompanied by elevation of aortic pressure, reflex bradycardia and increased femoral and renal resistances. Bileteral vagotomy was followed by hypertension, tachycardia and increased renal resistance. Changes in femoral resistance to these procedures differed between the two strains of miniature swine studied. Stimulation of the peripheral end of either vagus nerve was accompanied by bradycardia without hypotension.

Anesthesia↗
PubMed1979

Malignant melanoma in the Sinclair miniature swine: an autopsy study of 60 cases.

Sinclair miniature swine spontaneously develop multiple cutaneous melanomas which have the ability to metastasize and regress. This study, based on 60 necropsies, documents the similarity of the pathology of the cutaneous malignant melanomas and the organ distribution of metastasis to human melanoma. The invasive cutaneous melanomas have an intraepidermal component analogous to human superficial spreading melanoma. The pathology of the spontaneous regression, characterized by a series of cellular events beginning with a mononuclear inflammatory infiltrate and leading to depigmentation and fibrosis, is likewise similar to cutaneous regression in human melanoma. Just as with human melanoma,metastasis was correlated with deeply invasive cutaneous tumors. Because of both the biologic and histologic similarity of this animal model to human melanoma, the Sinclair miniature swine should serve as an important resource in continuing the study of melanoma.

Animals↗
PubMed1979

A method to provide secure attachment of miniature electric connectors in free-moving animals.

A connection assembly for miniature electric plug and socket systems used in the recording and stimulation of the brain in free-moving animals was constructed from sew-on dress snaps. Two male portions of the snaps were cemented to the miniature electric socket or the dental acrylic mound that attached the socket to the skull. The female portions of the snaps were sewn to the ends of an elastic band. The wires that lead to the commutator passed through a hole in the elastic band. The plug and socket were securely attached to one another by snapping the elastic band to the skull.

Animals↗
PubMed1968

Ethiopian cardiovascular studies. Case-finding by mass miniature radiography.

No large series of patients with cardiovascular disease has yet been reported from Ethiopia, where only limited means for investigation are at present available. The authors therefore studied the types of heart disease detected by mass miniature radiography in a largely self-selected population at the Addis Ababa Tuberculosis Centre, and examined the value of this method of cardiac case-finding. Rheumatic heart disease occurred in 34.8% of patients, but syphilitic aortitis, hypertension, "cardiomyopathy" and tuberculous pericarditis were also common. Endomyocardial fibrosis was not seen; this may be a further significant fact in the search for its cause. Mass miniature radiography is valuable for detecting symptomatic patients with the cardiovascular diseases mentioned above. The technique described in this paper could be used in other developing countries as it uses a single method of screening for 2 groups of diseases.

Adolescent↗
PubMedDate not supplied

[Biochemical typing of salmonellae by a miniaturized system (API - 50 E) (author's transl)].

The biochemical properties of clinical isolates of Salmonella have been studied by means of a commercially available miniaturized system (API - 50 E), which permit an easier examination of 50 chemical reactions. This miniaturized system seems to be helpfull not only in epidemiological researches but also in characterization of "atypical strains".

Computers↗
PubMed1978

Rapid miniaturized chromatographic quality control procedures for iodinated radiopharmaceuticals.

A rapid, miniaturized chromatographic system was developed to determine the labeling efficiency of iodinated radio-pharmaceuticals including I-131 orthoiodohippurate, I-131 rose bengal, I-125 RISA, and I-131 19-iodocholesterol. The system consists of three specific chromatography strips (Whatman 31ET paper chromatography, silica gel and silicic acid instant thin-layer chromatography) and three solvents (chloroform:glacial acetic acid in a 1.00:0.05 v/v mixture, absolute methanol, and 0.9% sodium chloride). The strips are color-coded, miniaturized, and appropriately labeled. The chromatographic quality control procedures are easy to use, rapid, and can be incorporated easily in a routine quality control program.

Chromatography↗
PubMed1980

Test for 'miniature flies' following exposure of Drosophila melanogaster larvae to diagnostic levels of ultrasound.

An attempt has been made to replicate an experiment which reported the appearance of 'miniature flies' after exposure of Drosophila melanogster larvae to the field of a pulsed diagnostic ultrasound unit. No effects were observed with 1.5 mW temporal average acoustic power, the level of the original report. However, when temporal peak powers were increased by a factor of 10, approximately one fourth of the larvae failed to survive to the imago stage. No miniature flies were seen in the entire study.

Animals↗
PubMed1982

A technique for bioinstrumentation of the thorax of miniature swine.

A surgical technique for sternal thoracotomy was developed for use in miniature swine. An incision was made from the midpoint of the neck to the tip of the xiphoid cartilage. The thorax was entered by dividing the sternum along its long axis with an electric oscillating saw. The thoracotomy was closed with 3-mm wide polyester fiber umbilical tapes placed around each sternebrae to appose the cut surfaces. The technique provided good access to the cranial vena cava, both atria and appendages, both ventricles, great cardiac veins, coronary sinus, ascending aorta and arch, and the pulmonary artery. Miniature swine tolerated this procedure well. It appeared to be less painful than lateral approaches and produced fewer pleural adhesions because only the mediastinum was entered.

Animals↗
PubMed1982

Cell mediated immune response in miniature Sinclair swine bearing cutaneous melanomas.

Miniature Sinclair swine bearing cutaneous melanomas and nonmelanoma bearing littermate controls were tested for lymphocyte blastogenic response in a microculture assay. Lymphocytes were assayed for 3H-thymidine incorporation following stimulation with concanavalin A, phytohemagglutinin or pokeweed mitogen. Treatment with all mitogens revealed a significantly (p less than 0.05) reduced proliferative capacity in melanoma swine as compared to littermate controls. These results lend further support for the use of miniature Sinclair swine as a research model for human melanoma.

Animals↗
PubMed1980

Hereditary esophageal dysfunction in the Miniature Schnauzer dog.

Miniature Schnauzers maintained in a colony for 9 years were used to study the inheritance of esophageal dysfunction (canine achalasia, megaesophagus). All dogs were evaluated radiographically, using a barium swallow contrast technique which clearly distinguished normal and affected pups. At 4 to 6 months of age, all affected dogs had recovered clinically except one, and radiographic evidence of dysfunction was markedly diminished. None of the affected dogs required a special feeding regimen. Analysis of breeding pairs revealed a ratio of 9 affected/11 normal dogs when an affected male was mated with a normal female, and a 13/3 ratio was observed when two affected dogs were mated. These ratios were compatible with a simple autosomal dominant or a 60% penetrance autosomal-recessive mode of inheritance. Outbreeding to an affected Miniature Schnauzer/Poodle crossbred dog resulted in only two of 30 affected pups, indicating a polygenic mode of inheritance in outbred populations.

Animals↗
PubMed1980

The effects of egg yolk diet on serum lipids, aortic atherosclerosis and connective tissue in male miniature pigs.

The effects of feeding an experimental diet consisting of 16.25% (w/w) dry powdered egg yolk and 30.8% total fat (20% from lard) was compared with an isocaloric amount of control (stock) regimen in male Hormel miniature pigs. The experimental diet was started at 30 weeks of age. The serum lipids (cholesterol and triglycerides) were determined at 5- week intervals until 55 weeks of age. At 55 weeks, the pigs were sacrificed and aortae evaluated for fatty streaks and atherosclerotic lesions. The ingestion of egg yolk diet resulted in hypercholesterolemia as the final serum fold over its initial value. Initial and final serum cholesterol levels of the controls were not statistically different. Triglyceride concentrations were nof influenced by an egg yolk regimen. It was observed that thoracic and abdominal atherogenesis was markedly increased in pigs fed the experimental diet as compared to the controls. No lesions were observed in the coronary arteries. There were no significant changes in the percent of collagen, elastin or C/E ratio in the thoracic and abdominal aortae as well as the coronary arteries. These results indicate that feeding miniature pigs an egg yolk : larg diet produced hypercholesterolemia, increased fatty streaking and atherosclerosis in the aortae.

Animals↗
PubMed1981

[Genetic characteristics of the 1st Soviet miniswine, Minisibs (miniature Siberian swine). I. The breeding of Minisibs and their morphophysiological properties].

The first form of laboratory mini-pigs "Minisibs" (miniature siberian swine) in USSR is the result of the distant hybridization and of the system of complex crosses between domestic and wild pigs of European and Asiatic origin (Sweden Landrace, Black Vietnamese, Sus scrofa ferus, Sus scrofa nigripes). "Minisibs" have a very small size, their live weight at birth is 517.16 +/- 6.48 g, at the age of two months--4.72 +/- 0.13 kg, at the age of 6 months when sexual maturity is achieved--19.02 +/- 0.89 kg and at the age of 12 months when they are adult males--29.75 +/- 2.98, females--35.35 +/- 0.01 kg. More than 88% of "Minisibs" are white, they have calm behaviour, are omnivorous, tolerant to a wide range of ecological conditions. "Minisibs" have a set of immunogenetical and cytogenetical features, in which they differ from other known miniature pigs. One of these features is the chromosome polymorphism: "Minisibs" have a 2n = 38, 37 and 36 karyotypes. "Minisibs" are very similar to a man in morphological and physiological parameters of many organs, and in the course of various pathological processes. For these reasons, mini-pigs "Minisibs" can be efficiently used as the best adequate model in the large scope of medical and biological programmes.

Animals↗
PubMed1981

Transplantation in miniature swine. IX. Swine histocompatibility antigens: isolation and purification of papain-solubilized SLA antigens.

Histocompatibility antigens have been purified by papain treatment of crude cellular membranes obtained from spleen and mesenteric lymph nodes of individual miniature swine that are homozygous at the major histocompatibility complex. The purification protocol included ultracentrifugation, gel filtration, ion-exchange chromatography, and in some instances preparative isoelectric focusing. This procedure was applied to the preparation of sLA antigens from the 3 haplotypes available in our partially inbred miniature swine herd. The purity of the SLAdd molecules was evidenced by: 1) a single activity peak of approximately 50,000 daltons on gel-permeation chromatography; 2) the antigen elution as a symmetrical peak from ion-exchange resins and from isoelectric focusing columns; 3) the presence of 2 predominant polypeptide chains on SDS-PAGE at apparent m.w. 43,000 and 13,000 daltons; and 4) specific immunoprecipitations by alloantisera and by anti-beta 1 microglobulin antisera. The antigenic activity of SLA products was analyzed by inhibition of complement-mediated cytotoxicity and by removal on anti-beta 2-microglobulin affinity columns. Heavy and light chains were separated by gel-filtration on Sephacryl S-200 in 6 molar guanidine. These SLA products, which have thus been shown to be pure by a variety of criteria, are now readily available for structural analysis and for analysis of biologic activity.

Animals↗
PubMed1981

Genetic selection for small body size in Yucatan miniature pigs.

Yucatan miniature swine exhibiting smaller than average size and weight were selected as foundation stock for a miniaturization program. The F1 progeny from four matings of parent stock were evaluated based on weight through 24 months of age. Those animals with a mature weight at least 20% below the average of the population were selected as breeding stock for the succeeding generations. The selected F1 boars, when compared in size to the mean weight of unselected adult boars, were significantly lighter (p less than 0.01). Selected F1 sows were significantly lighter (p less than 0.001) compared to unselected sows of a comparable age.

Animals↗
PubMed1981

A method for quantitation of hepatic, pancreatic, and intestinal function in conscious Yucatan miniature swine.

A right laparotomy was performed in anesthetized miniature swine. A hepatic vein was catheterized through the diaphragmatic surface of the left lateral lobe of the liver or through the cut surface of the right lateral lobe following a partial lobectomy. Continuous wave Doppler flow cuffs were applied to the hepatic artery and portal vein. Portal vein catheterization was accomplished through a stab incision made through the center of a preplaced purse string suture. Catheters and flow cuff wires exited the abdomen at the dorsal limit of the incision and were placed in nylon packs. Sterile surgery of the right ventro-lateral cervical region allowed catheterization of the right external jugular vein and carotid artery. These catheters were passed subcutaneously to the dorsum of the neck and inserted into another nylon pack. This method allowed repetitive experiments on conscious miniature swine after recovery from surgery. It allowed accurate quantitative determination of hepatic extraction of hormones as well as extraction of production of metabolites. Rates of intestinal absorption and pancreatic hormone secretion also could be assessed.

Animals↗
PubMed1980

Granulomatous interstitial pneumonia in a miniature swine associated with repeated intravenous injections of Tc-99m human serum albumin: concise communication.

Albumin lung-scanning agents have a proven high degree of safety, with the only contraindication to their use being allergic hypersensitivity. We have used these agents to investigate the physiologic effects of high Gz acceleratory forces on pulmonary perfusion using the miniature swine. Multiple doses of human macroaggregated albumin and human-albumin microspheres were given to a miniature swine at various levels of centrifugal acceleration over a 6-wk period. The dosages given were the same per kilogram as those used for routine clinical human studies. The animal subsequently died from a severe granulomatous interstitial pneumonia. The granulomatous lesions suggest that the pathogenesis may have involved a cell-mediated delayed hypersensitivity. This interstitial pneumonia may represent the end point in a chronic hypersensitivity response to the human-albumin lung-scanning agents.

Animals↗
PubMed1980

Experimental induction of struvite uroliths in miniature schnauzer and beagle dogs.

Urease positive staphylococcal urinary tract infection was experimentally induced in 13 dogs. Eight dogs developed cystic and/or urethral struvite calculi in 2 to 8 weeks. No abnormalities in systemic cell mediated immunity were detected in dogs before or after the establishment of the urinary tract infection. Miniature schnauzers whose ancestors had developed stones seemed to be no more susceptible to experimental urinary tract infection and stone formation than miniature schnauzers or beagles whose ancestors did not develop stones.

Animals↗
PubMed1980

Coronary blood flow during +Gz stress in +Gz conditioned adult miniature swine.

Four female adult miniature swine were acceleration conditioned for a period of 1 month using repeated acute exposure to simulated aerial combat maneuver profiles which exposed the animals to an average of +4.5G, for 106s. This period of conditioning produced adaptation as evidenced by decreased maximal heart rates during +Gz and by the absence of any +Gz induced gross cardiac pathology. Coronary blood flow was measured in these conditioned animals with the radiolabeled microsphere technique. Blood flows were measured under resting conditions, during 60s exposures to +3Gz and +5Gz and 10 min after +5Gz exposure. Coronary flow was increased 2-3 fold during +3Gz and +5Gz. The regional distribution of coronary blood flow during +Gz was similar to that under resting control conditions. There were no significant differences between coronary blood flows during +Gz in these conditioned animals and the values previously reported from the initial exposure of miniature swine to similar levels of +Gz. These results indicate that 1 month of acceleration conditioning of the types used in these studies has no significant effect on the response of coronary blood flow to +3Gz and +5Gz stress.

Acceleration↗