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PubMed2004

Leukocyte filtration and miniature perfusion during arrested heart CABG on a Jehovah's Witness patient.

Bloodless surgery and a reduction in the use of allogeneic blood products has long been the standard of care in medicine. Many individuals in our communities have demanded this form of surgical treatment for personal and religious reasons. On 6 December 2002, a 72-year-old male patient was admitted to our institution as a critical air flight transfer. The patient's height was 190.5 cm and weight was 59.3 kg (body surface area 1.83 m2). His preliminary diagnosis was chest pain with myocardial infarction as evidenced by elevated blood cardiac isoenzymes. His principle diagnosis was subendocardial infarction with paroxysmal ventricular tachycardia. Cardiac catheterization was performed and demonstrated severe triple vessel disease with an ejection fraction of 30%. He was evaluated and accepted as a candidate for coronary artery bypass grafting. Multidisciplinary consultation concluded that a safe and effective method of perioperative treatment would involve the use of arrested heart support with cold blood cardioplegia using a low prime miniature perfusion circuit as no blood products would be considered for use. Additionally, the combined modalities of perfusion interventions to minimize hemodilution consisted of intraoperative autologous blood collection totaling 500 mL and rapid autologous priming of the miniature perfusion circuit. The miniature perfusion system was a low prime Cardiovention (Santa Clara, CA) CORx device which includes a hollow-fiber oxygenator and integral centrifugal pump with a surface area of 1.2 m2. This system also incorporates an air sensing solenoid which triggers rapid air evacuation in a bolus range of 1 mL or greater. Kinetic venous drainage is another feature of this device as the centrifugal pump is integrated into the oxygenator. We believed that a miniature extracorporeal circuit would enhance the desired clinical outcome as opposed to the risk of: (1) off-pump coronary artery bypass (OPCAB) approach and the concern of emergent transition to an on-pump procedure and (2) use of larger surface area with conventional systems that impose a greater hemodilutional effect. Leukocyte filtration was employed as the patient had a significant past medical history of chronic obstructive pulmonary disease. We herein report our clinical experience with this method of treatment on a patient who refused the use of blood products in his surgical treatment. It is our belief that the multiple modalities utilized in combination during this procedure resulted in positive clinical outcomes as demonstrated by an intubation time of 8 hours 35 min with a discharge on the fifth postoperative day.

Aged↗
PubMed2006

Induction of estrus by prostaglandin F2alpha administration in the vaginal vestibules of miniature pigs.

Estrus induction is an important step in embryo production. It has been difficult to induce estrus in miniature pigs by intramascular (i.m.) injection of prostaglandin F2alpha (PGF2(2alpha)) in the early luteal stage of the estrous cycle. In the present study, we injected two different doses of PGF2(2alpha) i.m. and into the submucosa of the vaginal vestibule (i.ves.) of miniature pigs, and examined the effect of these treatments on estrus induction. Fifteen miniature pigs were divided into five experimental groups (control, saline injected i.m.; PGF2alpha treated, 1.0 or 1.5 mg of PGF2alpha injected twice i.m. or i.ves.), and the estrus length and concentrations of 17beta-estradiol (E2) and progesterone (P) in the blood were examined. Estrus length was significantly shortened by a large amount of PGF2alpha injected i.ves. In addition, the concentration of P in the blood significantly decreased after two injections of PGF2alpha (i.m. or i.ves.). These results suggest that in miniature pigs, administration of at least 3.0 mg of PGF2alpha is required for the induction of luteolysis and injection of PGF2alpha into the vaginal vestibule is a useful method of estrus induction.

Administration, Intravaginal↗
PubMed2001

Pharmacokinetics of phenylbutazone and its metabolite oxyphenbutazone in miniature donkeys.

OBJECTIVE: To describe the pharmacokinetics of phenylbutazone and oxyphenbutazone after IV administration in miniature donkeys. ANIMALS: 6 clinically normal miniature donkeys. PROCEDURE: Blood samples were collected before and 5, 10, 20, 30, 45, 60, 90, 120, 180, 240, 300, 360, and 480 minutes after IV administration of phenylbutazone (4.4 mg/kg of body weight). Serum was analyzed in triplicate by use of high-performance liquid chromatography for determination of phenylbutazone and oxyphenbutazone concentrations. The serum concentration-time curve for each donkey was analyzed separately to estimate model-independent pharmacokinetic variables. RESULTS: Serum concentrations decreased rapidly after IV administration of phenylbutazone, and they reached undetectable concentrations within 4 hours. Values for mean residence time ranged from 0.5 to 3.0 hours (median, 1.1 hour), whereas total body clearance ranged from 4.2 to 7.5 ml/kg/min (mean, 5.8 ml/kg/min). Oxyphenbutazone appeared rapidly in the serum; time to peak concentration ranged from 13 to 41 minutes (mean, 26.4 minutes), and peak concentration in serum ranged from 2.8 to 4.0 mg/ml (mean, 3.5 microg/ml). CONCLUSION AND CLINICAL RELEVANCE: Clearance of phenylbutazone in miniature donkeys after injection of a single dose (4.4 mg/kg, IV) is rapid. Compared with horses, miniature donkeys may require more frequent administration of phenylbutazone to achieve therapeutic efficacy.

Animals↗
PubMed2002

Detection of a genetic mutation for myotonia congenita among Miniature Schnauzers and identification of a common carrier ancestor.

OBJECTIVE: To develop a molecular genetic test to detect the mutant skeletal muscle chloride channel (CIC-1) allele that causes myotonia congenita in Miniature Schnauzers and to analyze the relationship of affected and carrier dogs. ANIMALS: 372 Miniature Schnauzers from the United States, Canada, Australia, and Europe that were tested between March 2000 and October 2001. PROCEDURE: The sequence surrounding the mutation in the CIC-1 allele was amplified by use of a unique pair of primers. Polymerase chain reaction (PCR) products were digested with the restriction enzyme Hpy CH4 III and separated on a 6% polyacrylamide gel. Pedigrees from all available carrier and affected dogs were analyzed, and a composite pedigree was established. RESULTS: Enzyme digestion of PCR products of the normal CIC-1 allele resulted in 3 fragments of 175, 135, and 30 bp, whereas PCR products of the mutant allele resulted in fragments of only 175 and 165 bp. Of the 372 Miniature Schnauzers, 292 (78.5%) were normal, 76 (20.4%) were carriers, and 4 (1.1%) were affected (myotonic) dogs. Frequency of the mutant allele was 0.113. Pedigree analysis revealed that a popular sire, documented to be a carrier, was a common ancestor of all carriers and affected dogs. CONCLUSIONS AND CLINICAL RELEVANCE: A PCR-based enzyme digestion DNA test was developed. The mutant allele for this disease is frequent in Miniature Schnauzers that are related to a common carrier ancestor. Breeding dogs should be tested by this specific DNA test to help limit the spread of this deleterious mutation.

Animals↗
PubMed1992

An analysis of miniature synaptic events recorded from locust muscle--variations in amplitude and time courses.

A study of miniature post-synaptic potentials (min. e.p.s.p.'s) in metathoracic extensor tibiae muscle fibres at neuromuscular junctions of adult locusts (Schistocerca gregaria) has been undertaken. Extracellular min. e.p.s.p.'s recorded from single junctional sites and their "marked" intracellular min. e.p.s.p. counterparts varied both in time course and amplitude and at many sites a small proportion of abnormal miniatures were observed, i.e., of large amplitude and/or of long duration. Positive correlations between the rise times and 1/2-decay times of the extracellular min. e.p.s.p.'s and between rise times and amplitudes and 1/2-decay times and amplitudes of "marked" intracellular events were found. Comparison of results obtained from differently innervated muscle fibres demonstrates that the occurrence of abnormal miniatures is independent of the type of innervation i.e., "fast" or "slow" excitatory motoneurons. Mechanisms that lead to the occurrence of abnormal miniatures are discussed in relation to the presence of large vesicles in the terminals of the excitatory motoneurons but the occurrence of these events could equally well be explained by the "post-synaptic saturation hypothesis".

Animals↗
PubMedDate not supplied

[Amplitude of miniature potentials of motor neurons in the frog Rana ridibunda].

Miniature synaptic potentials have been recorded from motoneurones of the isolated spinal cord of the frog Rana ridibunda. In normal Ringer's solution, their frequency varied from 5 to 50/sec, whereas their amplitude reached 2-5 mV. Only 50-300 microV (rarely 0.5-1.5 mV) potentials persisted when TTX was added to Ringer's solution and/or Ca was replaced by Mn. However, in Ca-free solution, TTX in combination with Mn did not decrease the amplitude of miniature potentials, provided the initial values varied within 50-300 microV. Noise fluctuations did not exceed 40-50 microV, and the ratio of the number of miniature potentials of 50 microV to the number of 50 microV noise potentials was about 10:1. The observed miniature potentials with an amplitude of 50-100 microV coincide with the quantal units calculated by other authors from statistical analysis of the unitary EPSPs evoked by primary afferents or by ventrolateral tract fibers.

Animals↗
PubMed2002

Miniaturized capillary isoelectric focusing in plastic microfluidic devices.

We report the demonstration of miniaturized capillary isoelectric focusing (CIEF) in plastic microfluidic devices. Conventional CIEF technique was adapted to the microfluidic devices to separate proteins and to detect protein-protein interactions. Both acidic and basic proteins with isoelectric points (pI) ranging from 5.4 to 11.0 were rapidly focused, mobilized, and detected in a 1.2 cm long channel (50 microm deep x 120 microm wide) with a total analysis time of 150 s. In a device with a focusing distance of 4.7 cm, the separation efficiency for a basic protein, lysozyme, was achieved as high as 1.5 x 10(5) plates, corresponding to 3.2 million plates per meter. We also experimentally confirmed that IEF resolution is essentially independent of focusing length when the applied voltage is kept the same and within a range that it does not cause Joule heating. Further, we demonstrated the use of miniaturized CIEF to study the interactions between two pairs of proteins, immunoglobulin G (IgG) with protein G and anti-six histidine (anti-6xHis) with 6xHis-tagged green fluorescent protein (GFP). Using this approach, protein-protein interactions can be detected for as little as 50 fmol of protein. We believe miniaturized CIEF is useful for studying protein-protein interactions when there is a difference in pI between a protein-protein complex and its constitutent proteins.

Electrophoresis, Capillary↗
PubMed1999

Analysis of protein-peptide interaction by a miniaturized fluorescence polarization assay using cyclin-dependent kinase 2/cyclin E as a model system.

As a result of the increasing size of chemical libraries, more rapid and highly sensitive strategies are needed to accelerate the process of drug discovery without increasing the cost. One means of accomplishing this is to miniaturize the assays that enter high-throughput screening (HTS). Miniaturization requires an assay design that has few steps, has a large degree of separation between the signal and background, and has a low well to well signal variation. Fluorescence polarization (FP) is an assay type that, in many cases, meets all of the above requirements. FP is a homogenous method that allows interactions between molecules to be measured directly in solution. This article demonstrates the application of FP in a miniaturized HTS format, using 1536-well plates, to measure direct binding between cyclin-dependent kinase 2/cyclin E complex (CDK2/E) and an 8-mer-peptide kinase inhibitor. The data indicate that low variability and high specificity allow rapid and precise identification of antagonist compounds affecting CDK2/E-peptide interactions.

CDC2-CDC28 Kinases↗
PubMed2000

Evaluation of silica resins for direct and efficient extraction of DNA from complex biological matrices in a miniaturized format.

For DNA purification to be functionally integrated into the microchip for high-throughput DNA analysis, a miniaturized purification process must be developed that can be easily adapted to the microchip format. In this study, we evaluate the effectiveness of a variety of silica resins for miniaturized DNA purification and gauge the potential usefulness for on-chip solid-phase extraction. A micro-solid-phase extraction (muSPE) device containing only nanograms of silica resin is shown to be effective for the adsorption and desorption of DNA in the picogram-nanogram mass range. Fluorescence spectroscopy as well as capillary electrophoresis with laser-induced fluorescence detection is employed for the analysis of DNA recovered from solid-phase resins, while the polymerase chain reaction (PCR) is used to evaluate the amplifiable nature of the eluted DNA. We demonstrate that DNA can be directly recovered from white blood cells with an efficiency of roughly 70%, while greater than 80% of the protein is removed with a 500-nl bed volume muSPE process that takes less than 10 min. With a capacity in the range of 10-30 ng/mg of silica resin, we show that the DNA extracted from white blood cells, cultured cancer cells, and even whole blood on the low microliter scale is suitable for direct PCR amplification. The miniaturized format as well as rapid time frame for DNA extraction is compatible with the fast electrophoresis on microfabricated chips.

Adsorption↗
PubMed1994

Distribution of forebrain diffuse axonal injury following inertial closed head injury in miniature swine.

Diffuse axonal injury (DAI) is one of the most frequently encountered types of brain damage resulting from closed head injury. This study was designed to verify whether DAI could be produced in miniature swine by rapid acceleration and deceleration of the head in the coronal plane. Hanford miniature swine (16-19 kg) were anesthetized with 3% isoflurane and their heads accelerated rapidly once through a 60-105 degrees arc in the coronal plane, producing only transient post-traumatic unconsciousness without prolonged coma. All animals made a good recovery and were sacrificed between 6 h and 10 days after injury. The response of forebrain projection systems to this injury was studied using neurofilament immunohistochemistry with antisera to nonphosphorylated (SMI-32) and phosphorylated (SMI-31) epitopes common to heavy (200 kDa) and medium (160 kDa) neurofilament proteins. In 9 of 12 animals, lesions characterized by foci of SMI-32 positive axonal retraction balls were present at the white matter/gray matter junction at the crests of gyri in the dorsolateral regions of the frontal, parietal, and temporal cortices and along margins of the lateral ventricles. A high density of pyramidal neuron perikarya in layers III and V within cortical gyri associated with subcortical DAI were intensely positive for SMI-31 immunohistochemistry. These results validate the use of miniature swine in studies of axonal injury and demonstrate that axonal injury analogous to that seen in the mildest form of DAI (grade I) can be produced in these animals without producing prolonged coma.

Animals↗
PubMed1985

A six month dermal irritation test with anthralins in the Göttingen miniature swine.

Anthralins, especially dithranol, have been used for the treatment of chronic dermatoses for many years. Unfortunately dithranol stains the skin yellow or brown. It also irritates healthy skin more than psoriatic areas. A new anthralin derivative, butantrone may be tolerated better. Because the skin of the swine resembles human skin in many respects, the Göttingen miniature swine was selected as the test animal for the present study. 12 Göttingen miniature swines of the uncoloured line were randomized into three groups. The two anthralin derivatives were spread in three separate bases (ointment, stick and gel) and in three concentrations each on the allocated skin sites on the flanks of the animals. The responses of the skin were evaluated daily (except Sundays) for six months. Because there was a separate group for the control animals (bases only), for dithranol and butantrone, it was possible to make observations on systemic toxicity, too. Butantrone and dithranol turned out almost equally irritating to the skin of the miniature swine. The mean primary irritation scores in the butantrone group were slightly higher than in the dithranol group. On the other hand, the concentrations of butantrone were higher. It is possible that the release of the drugs from the gel formula was poorer than from the ointment and stick bases.

Animals↗
PubMed2006

Potentially implantable miniature batteries.

All presently used batteries contain reactive, corrosive or toxic components and require strong cases, usually made of steel. As a battery is miniaturized, the required case dominates its size. Hence, the smallest manufactured batteries are about 50 mm3 in size, much larger then the integrated circuits or sensors of functional analytical packages, as exemplified by implantable glucose sensors for diabetes management. The status of the miniaturization of the power sources of such implantable packages is reviewed. Three microcells, consisting only of potentially harmless subcutaneously implantable anodes and cathodes, are considered. Because their electrolyte would be the subcutaneous interstitial fluid, the cells do not have a case. One potentially implantable cell has a miniature Nafion-coated Zn anode and a biocompatible hydrogel-shielded Ag/AgCl cathode. The core innovation on which the cell is based is the growth of a hopeite-phase Zn2+ conducting solid electrolyte film on the discharging anode. The film blocks the transport of O2 to the Zn, preventing its corrosion, while allowing the necessary transport of Zn2+. The second cell, with the same anode, would have a bioinert hydrogel-shielded wired bilirubin oxidase-coated carbon cathode, on which O2 dissolved in the subcutaneous fluid would be electroreduced to water. In the third cell, the glucose of the subcutaneous interstitial would be electrooxidized to gluconolactone at an implanted wired glucose anode, similar to that tested now for continuous glucose monitoring in diabetic people, and O2 in the subcutaneous fluid would be electroreduced to water on its wired bilirubin oxidase cathode.

Electricity↗
PubMed1999

Miniature laparoscopy: quo vadis? The basic parameters of image relay and display systems.

BACKGROUND: Endoscopy created a new epoch in gynecology and general surgery. After a decade of learning experiences and expansion of laparoscopic surgery in a variety of areas, the need to further miniaturize the endosurgical approach surfaced. This, however, requires a better knowledge about the tools that surgeons must or wish to employ in minimal access surgery. For miniaturization, the quality of the image on the TV monitor is critical. METHODS: We examined two miniature optical systems: the quartz-fiber (2.0-2.2 mm) and the rod-lens (3.3-mm) relay technologies. RESULTS: The smaller quartz telescope image was found to be brighter but lacking in other important features that are important in diagnosis and surgical manipulations. CONCLUSIONS: Because the detail, clarity, and the color display affect decision making and the course taken, the brand of telescope has to be selected according to the particular application. By following this guideline, a number of diagnostic and therapeutic procedures can be performed using smaller instruments with the patient under local anesthesia with sedation or under general anesthesia in an outpatient setting.

Endoscopes↗
PubMed2005

Towards miniaturization of a structural genomics pipeline using micro-expression and microcoil NMR.

In structural genomics centers, nuclear magnetic resonance (NMR) screening is in increasing use as a tool to identify folded proteins that are promising targets for three-dimensional structure determination by X-ray crystallography or NMR spectroscopy. The use of 1D 1H NMR spectra or 2D [1H,15N]-correlation spectroscopy (COSY) typically requires milligram quantities of unlabeled or isotope-labeled protein, respectively. Here, we outline ways towards miniaturization of a structural genomics pipeline with NMR screening for folded globular proteins, using a high-density micro-fermentation device and a microcoil NMR probe. The proteins are micro-expressed in unlabeled or isotope-labeled media, purified, and then subjected to 1D 1H NMR and/or 2D [1H,15N]-COSY screening. To demonstrate that the miniaturization is functioning effectively, we processed nine mouse homologue protein targets and compared the results with those from the "macro-scale" Joint Center of Structural Genomics (JCSG) high-throughput pipeline. The results from the two pipelines were comparable, illustrating that the data were not compromised in the miniaturized approach.

Gene Expression Regulation↗
PubMed1989

Diffusion of O2 in the retina of anesthetized miniature pigs in normoxia and hyperoxia.

Intraretinal oxygen tension (pO2) and local electroretinogram (ERG) were simultaneously measured in miniature pigs using double-barreled recess type microelectrodes. Transretinal pO2 profiles were recorded during normoxia and hyperoxia in areas close to (juxta-arteriolar) or far from (intervascular) retinal arterioles. In normoxia, in both areas, the pO2 decreased from the inner retina and the choroid towards the middle of the retina. In the inner retina the gradient of the juxta-arteriolar pO2 profile was steeper than that of the intervascular profile. This characteristic persisted during the breathing of 100% O2. Analysis of the pO2 profiles shows that, even in hyperoxia, the choroid cannot supply O2 to the whole retina. The results also support the conclusions of previous work (Riva, Pournaras and Tsacopoulos, 1986) indicating that in the normal retina it is not the O2 diffusing from the choroid to the retinal arterioles the induces vasoconstriction of these vessels. In the miniature pig this constriction appears to maintain inner retina tissue pO2 at a constant level during hyperoxia. From the pO2 transretinal profiles and previously published choroidal O2 fluxes and pO2 values near retinal vessels an explanatory working hypothesis is formulated according to which O2 consumption (qO2) of the outer retina increases during hyperoxia in the miniature pig.

Animals↗
PubMed1985

Direct synthesis of low-density lipoprotein apoprotein B in the miniature pig.

The metabolism of apoprotein B (apo B) was investigated in five miniature pigs following the injection of radiolabeled, very low-density lipoproteins (VLDL). The fractional catabolic rate (FCR) for VLDL apoprotein B was 0.71 +/- 0.10 h-1 (mean +/- SE), the rate of flux was 0.77 +/- 0.05 mg h-1 kg-1, and the pool size of apoprotein B averaged 1.26 +/- 0.20 mg kg-1. Examination of precursor-product relationships between VLDL and low-density lipoprotein (LDL) apoprotein B illustrated that a significant proportion (greater than 80%) of LDL apo B was derived from some source other than VLDL catabolism. In further experiments (n = 4), 125I-VLDL and 131I-LDL were simultaneously injected into miniature pigs. The fractional catabolic rate of LDL apo B averaged 0.055 +/- 0.008 h-1 and the flux rate 0.73 +/- 0.07 mg h-1 kg-1. These dual-label studies allowed us to calculate that an average of 16% of VLDL apoprotein B was converted to LDL and thus the remainder was cleared directly from the circulation. Simultaneous injection of radiolabeled homologous and human VLDL indicated that the catabolism of the two tracers was qualitatively similar. However, human VLDL apo B exhibited a slower fractional catabolic rate (0.42 v 0.71 h-1 P less than 0.05) and reduced rate of conversion to LDL. Therefore, low-density lipoproteins in the pig are largely produced by direct secretion into the circulation, independent of VLDL catabolism. Apo B metabolism in miniature pigs is similar to that of cynomologous and squirrel monkeys, and rats, but differs from normal humans in whom all LDL apo B is derived from VLDL catabolism.

Animals↗
PubMed1991

Experimental Isospora suis infections in miniature swine.

Clinical responses to experimental Isospora suis infections were compared in Sinclair miniature pigs and cross-bred conventional pigs. Pre-patent periods, fecal consistencies, oocyst excretion dynamics, trends in surviving pig weights and lesions were similar in infected miniature and conventional pigs. The results indicate that the susceptibility of miniature pigs to I. suis is similar to that of conventional pigs. These findings should encourage their use as models for the study of neonatal coccidiosis.

Animals↗
PubMed1988

Lipid composition of miniature pig platelets.

1. Analyses of platelet lipid composition were carried out on material pooled from male and female miniature pigs. 2. The cholesterol/phospholipid molar ratio was 0.6. 3. Phosphatidylcholine represents the major class of phospholipids (47%) and phosphatidylinositol the minor (2%). 4. The main fatty acids of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol and sphingomyelin were: palmitic, stearic, oleic, linoleic and arachidonic acids. 5. The ratios of saturated to unsaturated fatty acids were: sphingomyelin, 1.7; phosphatidylcholine, 1.2; phosphatidylserine, 0.9; phosphatidylethanolamine and phosphatidylinositol, 0.6. 6. Our results suggests that human and miniature pig platelet lipids bear several characteristics in common. This fact would allow miniature pig to be used as a new experimental model.

Animals↗