Urinary retention in diabetic patients.
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Aged↗
Biomedical subjects
S Fink
Publications and source records attributed to S Fink.
Physiologic considerations in radionuclide imaging of the extrahepatic biliary tract.
Scintigraphy of the biliary system using 99mTc-labeled radiopharmaceuticals enables the clinician to assess kinetics of bile flow through the gallbladder, common bile duct, and sphincter of Oddi. We review some aspects of biliary tract physiology and imaging which may be of interest to the physicians ordering and performing these studies.
Cholecystokinin↗
Clues to gallbladder dysfunction in patients with diabetic neuropathy.
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Diabetic Neuropathies↗
Some new methods for affixing sections to glass slides. I. Aqueous adhesives.
As a new aqueous adhesive to affix sections to glass slides, hydrolyzed vinyltriethoxysilane--either pure, in combination with polyvinyl alcohol or with specially prepared aqueous polyacrylate solutions--was applied. The silane proved to be very effective in enhancing bonding to the glass surface. As a general aqueous adhesive, a solution of 2% polyvinyl alcohol (m.w. 108,000; 99.7% hydrolyzed) with 0.2% hydrolyzed vinyltriethoxysilane is recommended. This stock solution is diluted 1:10 to 1:50 and used directly to float sections onto slides on a warming plate.
Adhesives↗
Some new methods for affixing sections to glass slides. II. Organic-solvent based adhesives.
Adhesion of various organic-solvent based adhesives to glass slides could be greatly improved by first priming the slide with a copolymer of allyl methacrylate and methacryloxypropyltrimethoxysilane. The use of different solvents and types of adhesives with these slides is discussed. Cellulose nitrate in different esters of acetic acid proved to be an effective adhesive for varied sections at room temperature and in the cryostat. Carbowax sections as a special case preferably were affixed with polyisobutylene in petroleum ether. Most of the attachments formed resisted even boiling water.
Adhesiveness↗
Some new methods for affixing sections to glass slides. III. Pressure-sensitive adhesives.
A variety of polymeric formulations have been evaluated for use as pressure-sensitive adhesives in affixing sections of fresh or frozen tissues for histochemistry and other purposes. The best adhesive with respect to water resistance, refractive index, and low temperature tack was polyisobutylene. In mixtures of different molecular weights this adhesive is specially suited for room temperature or cryostat use. Slides coated with this adhesive should only be used with staining or incubation solutions which have been filtered and degassed. Mounting cannot be performed with xylene-containing media, UV-curable monomeric media being favored. For anhydrous processing or nonpermanent preparations, polyethyleneimines, which are soluble in water but insoluble in xylene, may be used. Mixtures of polydimethylsiloxanes can be applied for subsequent temporary mounting with water or aqueous media.
Adhesives↗
Ceftriaxone effect on bilirubin-albumin binding.
The effect of ceftriaxone on bilirubin-albumin binding was measured in vitro using the peroxidase method with human serum albumin and a dialysis rate method with adult and newborn serum. Ceftriaxone competes with bilirubin for binding to human serum albumin; the displacement constant is 1.5 X 10(4) L/mol. Therapeutic levels of ceftriaxone decrease the reserve albumin concentration in newborn serum by 39%. These results indicate that ceftriaxone may increase the risk of bilirubin encephalopathy in jaundiced premature infants.
Adult↗
Enzyme-substrate interactions in the hydrolysis of peptide substrates by thermitase, subtilisin BPN', and proteinase K.
Peptide substrates of the general structure acetyl-Alan (n = 2-5), acetyl-Pro-Ala-Pro-Phe-Alan-NH2 (n = 0-3), and acetyl-Pro-Ala-Pro-Phe-AA-NH2 (AA = various amino acids) were synthesized and used to investigate the enzyme-substrate interactions of the microbial serine proteases thermitase, subtilisin BPN', and proteinase K on the C-terminal side of the scissile bond. The elongation of the substrate peptide chain up to the second amino acid on the C-terminal side (P'2) enhances the hydrolysis rate of thermitase and subtilisin BPN', whereas for proteinase K an additional interaction with the third amino acid (P'3) is possible. The enzyme subsite S'1 specificity of the proteases investigated is very similar. With respect to kcat/Km values small amino acid residues such as Ala and Gly are favored in this position. Bulky residues such as Phe and Leu were hydrolyzed to a lower extent. Proline in P'1 abolishes the hydrolysis of the substrates. Enzyme-substrate interactions on the C-terminal side of the scissile bond appear to affect kcat more than Km for all three enzymes.
Chymotrypsin↗
A new integrated concept for the improved preparation of sections of fresh or frozen tissue for light microscope histochemistry.
In order to obtain thin sections of plant tissues which combined good morphological preservation and the preservation of the substances and enzyme activities in the tissues, a concept of section preparation by external stabilization was developed. The main components are as follows: appropriate supporting medium; surface coating before each sectioning process, the coating being either non-permanent, permanent, or semi-permanent; suitable techniques for affixing the coated sections to the slides using either pressure-sensitive adhesive or solvent-based adhesive; and mounting media with defined refractive indices (preferably UV-curable, water-soluble monomers). By this approach, sections exhibiting excellent morphological and physiological preservation were obtained using either a cryostat at -30 degrees C or a rotary microtome at room temperature.
Adhesives↗
Diabetic secondary impotence: neuropathic factor as measured by peripheral motor nerve conduction.
Fifty-six type II diabetic males (mean age 52) were studied. Nineteen (33.9%) were diagnosed as having secondary impotence (SI); there was no correlation with age, diabetic control, and the use of insulin versus oral antidiabetic agents. Positive correlation was found between slow (less than 42 M/sec) motor nerve conduction velocity (MNCV) and SI at p less than 0.02, amounting to 58 per cent of the 19 cases. SI did not correlate with a standard list of peripheral neuropathic symptoms alone in the absence of slow MNCV. Correlation with SI was greatest when slow MNCV coexisted with neuropathic symptoms (p less than 0.04). MNCV testing may improve diagnosis and cost-effectiveness in assessing diabetic men with impotence.
Diabetic Neuropathies↗
Cardiorespiratory and conjunctival oxygen tension monitoring during resuscitation from hemorrhage.
Placement of an unheated miniaturized oxygen electrode against the palpebral conjunctiva permits noninvasive measurement of tissue oxygen tension. In this study, the relationship between conjunctival oxygen tension (PcjO2) and standard cardiorespiratory variables was examined during a sequential resuscitation protocol after acute hemorrhage. Anesthetized dogs were rapidly bled to a mean arterial pressure of 40 mm Hg and then retransfused with the shed blood in a stepwise fashion. PcjO2 fell to 2% of control values after hemorrhage and did not return to prehemorrhage values until more than 90% of the shed blood had been reinfused. PcjO2 was among the last set of cardiorespiratory variables to return to control values during resuscitation and was the last noninvasive variable to normalize. The ratio of PcjO2 to arterial oxygen tension decreased from a prehemorrhage value of 0.76 +/- 0.05 (SEM) to 0.02 +/- 0.003 after hemorrhage, and did not increase to values greater than 0.50 until resuscitation was more than 90% complete. Conjunctival oxygen monitoring may play an important role in assessing the adequacy of resuscitation after acute hemorrhage.
Animals↗
Effect of nifedipine on gastric emptying.
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Gastric Emptying↗
Continuous measurement of intravascular pH with a fiberoptic sensor.
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Animals↗
Oxygen transport and utilization in hyperoxia and hypoxia: relation of conjunctival and transcutaneous oxygen tensions to hemodynamic and oxygen transport variables.
A device to measure surface oxygen tension of the palpebral conjunctiva (PcjO2) was developed and tested in 12 mongrel dogs subjected to normoxia, hyperoxia, and hypoxia. Intravascular pressure, hemodynamic, and bulk oxygen transport variables were measured simultaneously with PcjO2 and transcutaneous O2 (PtcO2) and CO2 (PtcCO2). PcjO2 closely paralleled PaO2 as the fractional inspired O2 concentration was changed from 0.21 up to 1.0 and down to 0.05; the correlation coefficient, r, was 0.95 for 305 data sets. During hyperoxia there were no significant hemodynamic or bulk O2 transport changes, but during hypoxia, the cardiac output and O2 extraction increased while PaO2, PtcO2 and PcjO2 fell; O2 delivery and O2 consumption were maintained until just before death.
Animals↗
Effect of hemorrhagic shock on conjunctival and transcutaneous oxygen tensions in relation to hemodynamic and oxygen transport changes.
To evaluate possible physiologic mechanisms in hemorrhagic shock, sequential hemodynamics, O2 transport, conjunctival O2 (PcjO2), transcutaneous blood gases (PtcO2, PtcCO2), and core and conjunctival temperature (Tcore, Tcj) were measured during a control period, after hemorrhage, after reinfusion of the shed blood, and subsequently during terminal normovolemic shock in eight anesthetized dogs. The PtcO2 sensor requires surface heating to 44 degrees or 45 degrees C, whereas the PcjO2 sensor measures surface temperature but does not heat the tissue, thus avoiding heat-induced artifacts. Shortly after onset of hemorrhage, hemodynamic variables, bulk O2 transport, and tissue O2 tensions decreased abruptly. Prolongation of hemorrhage further deteriorated these variables. Reinfusion of the shed blood returned all values except PcjO2 to the normal range. In the terminal stage, all variables except PaO2 again deteriorated; decreased O2 transport impaired oxygen consumption, which in turn reduced both central and peripheral heat production. Lowered oxygen consumption, Tcore and Tcj reflect decreases in total-body and local tissue metabolism. These data are consistent with the concept that tissue O2 tension represents the balance between O2 supply and O2 demand and thus reflects overall O2 metabolism, which may be rate-limited by circulatory deficiencies.
Animals↗
Lack of effect of indomethacin on gastric emptying in old men.
Indomethacin, widely prescribed in the elderly, has a potential for affecting concomitant absorption of other drugs by changing gastric emptying time. A study of basal and post-indomethacin gastric emptying times (GET) in ten patients aged 69-86 (mean age 77) shows no significant change in GET after indomethacin administration. The data suggest that drugs whose potencies can be altered by gastric retention may be taken concomitantly with indomethacin.
Aged↗
Stimulatory effect of lymphocytes from Chagas' patients on spontaneously beating rat atria.
The aim of this work was to study the effect of lymphocytes from individuals infected with Trypanosoma cruzi (Chagas' patients) on the contractile behaviour of living heart tissue. Chagas' lymphocytes (ChL) reacted with isolated rat atria preparations increasing the isometric development tension (IDT) and frequency of contractions (FC) in a dose-dependent manner. The maximal stimulatory effect was reached after 30-40 min of contract. In contrast, normal lymphocytes (NL) did not alter the basal IDT and FC values. beta-adrenergic antagonists, anti-histamine agents and inhibitors of the synthesis and action of arachidonic acid (AA) products were used to study the mechanisms of the reaction. (-)-propranolol (10(-7)M) and pyrilamine (10(-6)M) had no effect ruling out the participation of beta-adrenergic agonists or histamine. However, indomethacin (10(-6)M) and acetylsalicylic acid (1.8 X 10(-4)M) enhanced the effect of ChL. Inhibitors of the lipoxygenase pathway (5,8,11,14-eicosatetraynoic acid, 10(-7)M; nordihydroguairetic acid, 10(-5)M) and FPL55712, an antagonist of one of its terminal products: the slow reacting substance of anaphilaxis (SRS-A), abolished the reaction. Therefore, a fundamental role for SRS-A in the production of the stimulatory effect is postulated. Lymphocytes of the T cell lineage (E rosette forming cells, ERFC) are the effector cells involved in this reaction, whereas non-rosetting ChL depressed IDT. T ascertain if effector cells could be replaced by soluble factors, ChL were reacted with homogenates of rat atria and the cell free supernatants were added to beating rat atria. Positive ino- and chronotropic effects were obtained, indicating that soluble factors generated during the reaction can substitute for the intact effector cells. On the other hand if the effector cells were purified from Chagas' patients that had been treated 1 month to 6 years before the assay with trypanocidal drugs (3-methyl-4-(5'-nitrofurfurylidene-amino)-tetrahydro-4H-1, 4-tiazine-1, 1-dioxide, nifurtimox or N-benzyl-2-nitro-imidazolacetamide, benznidazole) only depressor effects were found. The depressor inotropic action of lymphocytes from treated patients (tr-ChL) was abolished with indomethacin and acetyl salicylic acid indicating that products of the cyclooxygenase pathway of AA were involved. While this work provides additional evidence for the hypothesis that lymphocytes from T. cruzi infected patients may react with heart tissue and alter its contractile behaviour, the results should not be extrapolated to the in vivo situation.(ABSTRACT TRUNCATED AT 400 WORDS)
5,8,11,14-Eicosatetraynoic Acid↗
The eye as a peripheral sensor.
The eye is no longer an organ onto itself, but is now being used as a sensor for the rest of the body. The development, clinical uses, and future applications of conjunctival capillary monitoring are presented.
Adult↗