Search PubMed⌕ Search

Biomedical subjects

R E Kane

Publications and source records attributed to R E Kane.

At least 55 records · Page 3Linked to original sources

Metolazone and spironolactone in cirrhosis and the nephrotic syndrome.

Eighteen patients with hepatic cirrhosis or nephrotic syndrome and having edema and/or ascites were treated during successive periods with metolazone 5 to 40 mg/day, spironolactone 100 mg/day, and with both diuretics concurrently. Metolazone alone produced a marked diuresis, natriuresis, and weight loss in 8 patients. Spironolactone alone had little effect, but the addition of metolazone renewed diuresis and natriuresis and resulted in additional substantial weight losses in all patients responsive to metolazone alone. Concurrent spironolactone and metolazone also induced moderate diuretic effects in some patients who failed to respond to either drug alone. The drugs were well tolerated; the administration of spironolactone with metolazone prevented decreases in serum potassium, which had occurred during treatment with metolazone alone.

Adult↗

Long-term diuretic therapy with metolazone of renal failure and the nephrotic syndrome.

The effects of the new diuretic metolazone were studied in ten patients with chronic renal insufficiency and ten with nephrotic syndrome. Patients were maintained on metolazone for up to 44 months. Beneficial effects of treatment included loss of edema and improved control of blood pressure. The natriuretic effect of metolazone facilitated the use of sodium bicarbonate to treat acidosis in several patients. Concurrent administration of metolazone and furosemide produced a dramatic diuresis in one patient resistant to either diuretic alone. Adverse effects of metolazone therapy were those characteristic of other effective diuretics, Including serum electrolyte losses and hyperuricemia. Initial treatment produced small increases in serum creatinine among patients with renal insufficiency, suggesting that GFR was decreased secondary to diuresis-induced volume depletion. The study demonstrates that metolazone is both safe and effective over long periods of time.

Adult↗

Actin polymerization and interaction with other proteins in temperature-induced gelation of sea urchin egg extracts.

The gel which forms on warming the extracts of the cytoplasmic proteins of sea urchin eggs has been separated into two fractions, one containing F-actin and the other containing two proteins of 58,000 and 22,000 mol wt. When combined in 0.1 M KCl, even at 0 degrees C, these components will form gel material identical to that formed by warming extracts. This gel is a network of laterally aggregated F-actin filaments which are in register and which display a complex cross-banding pattern generated by the presence of the other two proteins. Low concentrations of calcium block the assembly of these proteins to form this complex structure, which may play some cytoskeletal role in the cytoplasm. This association of F-actin with the other proteins to form a gel is very likely the last step fo the process occurring in warmed extracts. At low temperatures, gelation of extracts is limited by the relative absence of F-actin, as demonstrated by the inability to sediment it at 100,000 g and also by the fact that gelation occurs immediately if exogenous F-actin is added to cold extracts. The transformation of the G-actin present in the extract to the F-form is apparently repressed at low temperatures. This is shown directly by the failure of added G-actin to polymerize at low temperatures in the presence of extract. These observations resemble those which have been reported on preparations from amoeboid cells and may be significant in the involvement of actin and these other proteins in cell division and later developmental processes.

Actins↗

Preparation and purification of polymerized actin from sea urchin egg extracts.

Isotonic extracts of the soluble cytoplasmic proteins of sea urchin eggs, containing sufficient EGTA to reduce the calcium concentration to low levels, form a dense gel on warming to 35-40 degrees C. Although this procedure is similar to that used to polymerize tubulin from mammalian brain, sodium dodecyl sulfate-polyacrylamide gel electrophoresis shows this gel to have actin as a major component and to contain no tubulin. If such extracts are dialyzed against dilute salt solution, they no longer respond to warming, but gelation will occur if they are supplemented with 1 mM ATP and 0.020 M KCl before heating. Gelation is not temperature reversible, but the gelled material can be dissolved in 0.6-1 M KCl and these solutions contain F-actin filaments. These filaments slowly aggregate to microscopic, birefringent fibrils when 1 mM ATP is added to the solution, and this procedure provides a simple method for preparing purified actin. the supernate remaining after actin removal contains the other two components of the gel, proteins of approximately 58,000 and 220,000 mol wt. These two proteins plus actin recombine to form the original gel material when the ionic strength is reduced. This reaction is reversible at 0 degrees C, and no heating is required.

Actins↗

Serological similarity of flagellar and mitotic microtubules.

An antiserum to flagellar axonemes from sperm of Arbacia punctulata contains antibodies which react both with intact flagellar outer fibers and with purified tubulin from the outer fibers. Immunodiffusion tests indicate the presence of similar antigenic determinants on outer-fiber tubulins from sperm flagella of five species of sea urchins and a sand dollar, but not a starfish. The antibodies also react with extracts containing tubulins from different classes of microtubules, including central-pair fibers and both A- and B-subfibers from outer fibers of sperm flagella, an extract from unfertilized eggs, mitotic apparatuses from first cleavage embryos, and cilia from later embryos. Though most tubulins tested share similar antigenic determinants, some clear differences have been detected, even, in Pseudoboletia indiana, between the outer-fiber tubulins of sperm flagella and blastular cilia. Though tubulins are "actin-like" proteins, antitubulin serum does not react with actin from sea urchin lantern muscle. On the basis of these observations, we suggest that various echinoid microtubules are built of similar, but not identical, tubulins.

Animals↗

Some properties of hyalin: the calcium-insoluble protein of the hyaline layer of the sea urchin egg.

The principal protein component of the hyaline layer of sea urchin eggs is the calcium-insoluble protein first described by Kane and Hersh. The protein hyalin is abnormally high in acidic amino acids, almost devoid of basic amino acids, and characteristically rich in valine and proline. Essentially all of the cysteine present is found in the disulfide form; no evidence points to intermolecular disulfide linkages. Hyalin from several species has a minimal subunit weight of about 100,000, though evidence exists for a particle three times this weight in urea or guanidine hydrochloride from one species. Optical rotatory dispersion measurements indicate no alpha-helix content, though the dispersion has unique characteristic features. Addition of small quantities of calcium causes hyalin to gel to a birefringent fibrous form. The fibrous, birefringent form of hyalin is rendered isotropic upon addition of EDTA, but the birefringence is restored with re-addition of divalent cation.

Animals↗

Direct isolation of the hyaline layer protein released from the cortical granules of the sea urchin egg at fertilization.

Treatment of the eggs of the sea urchin with a 1 M solution of glycerol at fertilization allows the recovery from this solution of the protein released from the cortical granules, including that which would normally give rise to the hyaline layer. The calcium-gelable protein previously extracted from whole eggs and from isolated cortical material was found to be present in the glycerol solution, confirming its localization in the cortical granules and its role in the hyaline layer. Quantitative measurements on the eggs of two Hawaiian species, Colobocentrotus atratus and Pseudoboletia indiana, which have the widest variation in the gel protein content, demonstrated that a proportionate amount of this material was released at fertilization in these species, which correlates with the thickness of the hyaline layer in the two cases. In addition, the calcium-insoluble fraction of Sakai can be extracted from these eggs after removal of the hyaline protein by glycerol, showing that this is a different material. A simple method for the separation of the hyaline protein from the calcium-insoluble fraction in solution is provided.

Animals↗

A comparative study of the isolation of the cortex and the role of the calcium-insoluble protein in several species of sea urchin egg.

A comparative study was made of the isolation of the cortex in the eggs of several sea urchin species. Since the isolation method developed by Sakai depends on the presence of magnesium in the medium, the protein composition of the cortex was investigated to determine whether the protein component of the egg described by Kane and Hersh which is gelled by divalent ions, is present in these cortices. Isolation of the cortex was found to require the same divalent ions at the same concentrations as protein gelation, and in the eggs of some species much of the gel protein of the cell was found in the isolated cortical material. In the eggs of other species a smaller fraction of this protein was found in the isolated cortex, although it was more concentrated there than in the endoplasm, and in one species this protein appeared to be uniformly distributed throughout the cell. These results indicate that this protein is localized in the cortical region of the eggs of some species of sea urchin, possibly in the cortical granules, but also point up the fact that results from one species cannot be uncritically extrapolated to others.

Animals↗

The mitotic apparatus. Identification of the major soluble component of the glycol-isolated mitotic apparatus.

Mitotic apparatuses (MA) isolated from metaphase sea urchin eggs in 12% hexylene glycol at pH 6.4 can be dissolved rapidly in 0.6 M KCl, and more than one-half of the total protein of the MA is soluble under these conditions. In the phase-contrast microscope, the fibrous structure of the MA can be seen to disintegrate in KCl solution, leaving only granular material which, in the electron microscope has been seen to be largely vesicular, with no evidence of microtubules or other fibrous elements. The KCl-soluble material thus must contain the soluble components of the microtubules and consists of one major, homogeneous component with a sedimentation coefficient of 22 Svedbergs, and a much smaller amount of more heterogeneous material sedimenting at 4-5S. A component similar to the 22S component can be identified in extracts of unfertilized eggs, where it forms approximately 8% of the total cell protein. The amount of this protein present in the cell is considerably in excess of that involved in the MA, as can be shown by its presence in the soluble supernate from a mitotic apparatus isolation. This protein must form part of, or be associated with, the fibrous structure of the MA in some fashion that allows its release only upon the dissolution of the mitotic apparatus.

Animals↗

The mitotic apparatus. Structural changes after isolation.

The fibrous structure of the mitotic apparatus (MA) isolated from dividing sea urchin eggs undergoes no changes visible in phase contrast during extended storage, but the solubility of the MA rapidly decreases after isolation. Polarization microscopy shows that a decrease in the birefringence of the MA also occurs after isolation and is correlated with the loss of solubility. This loss of birefringence indicates that some structural change takes place during this period, and such a change was demonstrated by means of electron microscopy. The tubular filaments which form the spindle of the intracellular MA and of the freshly isolated MA were found to break down during storage to rows of dense granules, this loss of continuity presumably accounting for the loss of birefringence. The interrelations of the observed changes and the significance of these observations for investigations on the isolated MA are discussed.

Animals↗

Regulation of bile salt sulfotransferase isoenzymes by gonadal hormones.

We studied the regulation of hepatic bile salt sulfotransferase activity by gonadal hormones and the effect of gonadal hormones on two bile salt sulfotransferase isoenzymes. Bile salt sulfotransferase enzyme activity was three times greater in the female than in the male rats. Oophorectomy significantly decreased bile salt sulfotransferase activity in the female, but orchidectomy had no effect on bile salt sulfotransferase activity in the male. Estrogen treatment of intact as well as orchidectomized males markedly stimulated the enzyme activity, while testosterone treatment of intact or oophorectomized females did not effect bile salt sulfotransferase activity. We concluded that the 3-fold greater activity in female rats is due to the striking stimulatory effect of estrogen on bile salt sulfotransferase activity, and the testosterone has little or no role in the sexually related differences in bile salt sulfotransferase activity in mature rats. These sex-related differences in bile salt sulfotransferase activity were investigated further using DEAE-Sephadex A50 ion-exchange chromatography of rat hepatic cytosol. Two bile salt sulfotransferase isoenzymes were identified both with an approximate molecular weight of 130,000. Bile salt sulfotransferase I eluted with 0.05 M NaCl, had an isoelectric point at pH 6.8, was stimulated by estrogen, and was responsible for 90% of total bile salt sulfotransferase activity in the mature female. Bile salt sulfotransferase II eluted with 0.14 M NaCl, had an isoelectric point at pH 5.3, was unresponsive to estrogen, and accounted for 75 to 80% of bile salt sulfotransferase activity in the mature male.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

An examination of the relationship between race, skin color and a series of autonomic nervous system measures.

In the total population of 75 subjects, the skin albedo correlated significantly with skin resistance, a relationship which was not maintained when the total population was separated into its component subgroups of whites, blacks and Indians. The Indians, "anthropologically Caucasians" but skin color more akin to the blacks, exhibited mean skin reflectance and skin resistance intermediate to that obtained in the black and white groups respectively. Other differences and significant correlations between the autonomic functions in the three groups indicated a higher level of sympathetic tone in the Indians, although this could be attributed to the older age of this group. It was suggested from the results that skin color rather than race has a greater influence on skin resistance.

Acoustic Stimulation↗

Comparison of low, medium, and high carbohydrate formulas for nighttime enteral feedings in cystic fibrosis patients.

This study examined whether the increase in CO2 production (VCO2) and ventilatory demands by carbohydrate loading with different formulas during nighttime enteral feedings could be detrimental in young adult cystic fibrosis patients with moderate to advanced lung disease. Ten patients age 17 to 24 (mean 21.4 years) received 1000 kcal/M2 of a low (Pulmocare), medium (Ensure Plus), and high (Vivonex HN) carbohydrate formula in random order. Eight patients had severe, and two moderate obstructive pulmonary disease; nine used nighttime oxygen therapy. Basal energy expenditure (BEE) without feedings averaged 120% of that predicted by the Harris-Benedict equation. The metabolic expenditure by indirect calorimetry during nighttime feedings was 25 to 36% greater than the BEE. Oxygen consumption (VO2) increased 21 to 27% during nighttime feedings with no difference between formulas. VCO2 increased 29% for Pulmocare, 46% with Ensure Plus, and 53% with Vivonex HN. The increase in VCO2 with Pulmocare was significantly less than Ensure Plus (p less than 0.05) and Vivonex HN (p less than 0.005). The respiratory quotient (RQ) (VCO2-/VO2) for Pulmocare (0.88) was the same as the BEE, but increased with Ensure Plus (1.00), and Vivonex HN (1.08). The 41% increase in minute ventilation with Vivonex HN was greater than the 25 to 28% increase observed for Pulmocare and Ensure Plus (p less than 0.05). Transcutaneous oxygen saturation fell no more than 2% with all formulas. PCO2 changed +/- 5 torr during enteral feedings with similar changes in any patient with all formulas.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗