The effect of solvents on nucleotide regulation of glycogen phosphorylase.

The activity of glycogen phosphorylase is controlled by two nucleotide sites. We have found that organic solvents affect the regulatory properties of phosphorylase by altering the binding at these two sites. At the activator site, the Ka for AMP is lowered 10-fold in the presence of 10% 1,2-dimethoxyethane while, at the inhibitor site, the Ki for caffeine is increased 6-fold. The stimulation of activity by organic solvents is highly dependent on the enzyme's activity state. Phosphorylase b, which has a requirement for a nucleotide activator, loses this requirement in the presence of organic solvents, while the active form of the enzyme, phosphorylase a, is only slightly stimulated by organic solvents. The activation profile obtained with rabbit liver phosphorylase suggests that differences in the properties of this enzyme from rabbit muscle phosphorylase might be explained by a change in the relative affinity for AMP at the two nucleotide sites. The results also suggest that 1,2-dimethoxyethane may be useful to determine accurately the activities of different forms of liver phosphorylase.


The activity of eukaryotic initiation factor eIF-2 in ternary complex formation with GTP and Met-tRNA.

Ternary complex formation between [3H]Met-tRNAf, [14C]H3-eIF-2, and GTP was measured on nitrocellulose filters. It is shown that [3H]Met-tRNAf and [14C]H3-eIF-2 are present on the filter in equimolar amounts when ATP, creatine phosphate, and creatine kinase are included in the reaction mixture. Under these conditions the factor is 100% active. With small amounts of factor significant losses occur due to adsorption to the wall of the reaction vessels, resulting in seemingly low activities of eIF-2. These losses can be prevented by the presence of "stimulatory" proteins, which enhance the recovery of both [3H]Met-tRNAf and [14C]H3-eIF-2 on the filter but do not alter their ratio.


Functional consequences of agonist-mediated state transitions in the cholinergic receptor. Studies in cultured muscle cells.

Parameters associated with activation and desensitization of the nicotinic receptor in the BC3H-1 muscle cell line have been compared with the state transitions that result upon combination with agonist. 125I-labeled cobra alpha-toxin is found to bind to an apparent single class of surface nicotinic receptors on the cells in situ with a rate constant of 1.15 x 10(5) M-1 s-1. The competition between cholinergic ligands and alpha-toxin reveals that agonists, but not classical antagonists, will promote a slow conversion to a receptor state where the affinity for agonists is enhanced. Moreover, agonists such as carbamylcholine elicit a permeability increase to 22Na+ ions that slowly decrements at a rate and to an extent closely paralleled by the conversion of the receptor to the high affinity state. Upon removal of the agonist, both the affinity increase and the diminished permeability change are completely reversible and again exhibit similar kinetics for their return to the original state. A comparison of the capacity of full agonists to compete with alpha-toxin binding and elicit a permeability change suggests that in the absence of agonist, receptor predominates in a low affinity activatable state. Binding of agonists to the low affinity state exhibits little if any cooperativity (n = 0.97 to 1.31), while the corresponding permeability change appears more cooperative (n = 1.31 to 1.52). By contrast, when receptors have been previously equilibrated with agonists, occupation of the receptor occurs over a 3- to 5-fold lower concentration range. Binding following equilibration closely correlates with a concomitant decrease in activatable receptor resulting from equivalent exposure to agonist. Furthermore, under equilibrium conditions, the binding of full agonists is typified by a moderate degree of homotropic cooperativity (1.25 to 1.44), enabling the receptor to desensitize over a narrow range of agonist concentration. Simultaneous measurement of occupation and activation parameters has enabled us to compare a state function for desensitization which is generated from binding parameters with the reduction in permeability seen in the desensitization process. A scheme describing the association of agonist with two functionally distinct receptor states is developed to account for the cooperative relationship between agonist binding and desensitization of the receptor.


A deoxyribonucleic acid binding protein from KB cells which inhibits deoxyribonuclease activity on single-stranded DNA.

A deoxyribonuclease inhibitor has been purified from KB cells by chromatography on single-stranded DNA-cellulose. Polyacrylamide gel electrophoresis showed the purified preparation to contain two major polypeptides in sodium dodecyl sulfate, with molecular weights of 72,000 and 65,000, but only one major band (with a molecular weight of approximately 140,000) after electrophoresis under nondenaturing conditions. The protein inhibits the hydrolysis of single-stranded DNA by KB DNase, DNase I, DNase II, and nuclease S1, but has no effect on the hydrolysis of double-stranded DNA by these enzymes. The inhibitor causes a reduction in the rate of hydrolysis of DNA by the deoxyribonuclease, probably by reducing the effective concentration of substrate.


Characterization of the nicotinic acetylcholine receptor isolated from goldfish brain.

We have studied the binding of alpha-bungarotoxin to a particulate fraction of goldfish brain enriched in synaptosomes. The binding is specific and saturable and exhibits the pharmacological properties of a nicotinic cholinergic receptor. Equilibrium binding measurements yield a single dissociation constant (KD) of 0.92 nM. Kinetic analysis revealed one association rate constant and two dissociation rate constants. Dissociation constants calculated from kinetic measurements were 1.9 nM and 12.5 pM. The toxin . receptor complex is readily solubilized in nonionic detergent. The isoelectric point of the toxin . receptor complex was found to be 5.00 +/- 0.01. Sedimentation velocity analysis in sucrose/H2O and sucrose/D2O gradients in conjunction with Sepharose 4B chromatography and diffusion experiments yielded a sedimentation constant of 11.45, a partial specific volume of 0.79 cm3/g for the toxin . receptor . detergent complex, and a molecular weight of approximately 340,000 for the toxin . receptor complex.


Partial amino acid sequence of the glutamate dehydrogenase of human liver and a revision of the sequence of the bovine enzyme.

The glutamate dehydrogenase from a single human liver has been studied. The subunit size was found to be 55,200 +/- 1,500 by sedimentation equilibrium. The partial specific volume is 0.732 as calculated from the amino acid composition. The sequence was determined by isolation of peptides after cyanogen bromide (CNBr) cleavage; the fraction containing the largest peptides was hydrolyzed by trypsin after maleylation. Studies on these peptides accounted for 454 residues of the 505 residues that are presumably present in the protein. For the 51 residues that were not represented in isolated peptides, we have tentatively assumed that the sequence is the same as that of the bovine enzyme. Methionine and arginine residues in these peptides could be placed on the basis of the specificity of cleavage by CNBr or trypsin. In all, 349 residues were placed in sequence, and were aligned by homology with the corresponding peptides of the bovine and chicken enzymes. From the present information, there are 24 known differences in sequence between the human and bovine enzymes and 41 between the human and chicken enzymes. In addition, the human enzyme contains 4 additional residues at the NH2 terminus as compared to the bovine enzyme. In a peptide from the human enzyme, an additional residue, isoleucine 385, was detected by automated Edman degradation. Reinvestigation of the bovine sequence demonstrated that this residue is also present in the bovine enzyme (and presumably in the chicken enzyme also). Residue 384 of the bovine enzyme, previously reported as Glx has now been shown to be glutamine.


The export of glutathione from human diploid cells in culture.

The export of glutathione from cultured human diploid fibroblasts into the surrounding medium was found by isotopic labeling experiments using [35S]cystine and by enzymatic measurements. The major part of the glutathione exported from the cells was found in normal culture medium as mixed disulfide of glutathione and cysteine. Radioactivity of 35S, mostly derived from cellular glutathione, was mainly located in glutathione moiety, not in cysteine moiety, of the mixed disulfide. Export of free glutathione was found when cystine-free medium was used. It was, therefore, concluded that mixed disulfide of glutathione and cysteine was formed in the medium by exported glutathione and medium cystine via sulfhydryl-disulfide exchange reaction. Amount of total glutathione exported from the cells was measured by enzymatic method and it was found that more than 10% of normal cellular glutathione was exported within 2 h. Apparent concentration of glutathione in the medium after a day of culture reached 3 to 4 micrometer, which was comparable to that observed in normal plasma by the same enzymatic method.


Effect of endogenous heme generation on delta-aminolevulinic acid synthase activity in rat liver mitochondria.

This study examined the possibility that generation of heme within mitochondria may provide a local concentration sufficient to inhibit the activity of delta-aminolevulinic acid (ALA) synthase, the enzyme that catalyzes the rate-limiting step in hepatic heme biosynthesis. This was accomplished by simultaneously running ALA synthase and heme synthase activities in intact mitochondria isolated from rat liver. Radiochemical assays were used to measure the enzyme activities. ALA synthase activity did not decrease as the rate of heme formation was increased by varying the concentration of substrates for heme synthase. Even at a rate of heme generation estimated to be at least 75 times the rate occuring in vivo, ALA synthase activity was unchanged. We conclude that end product inhibition of ALA synthase activity by heme is not an important physiological mechanism for regulation of hepatic heme biosynthesis.


Two crystal forms of Azotobacter ferredoxin.

Two crystal forms of Azotobacter vinelandii (4Fe-4s)2 ferredoxin I (Fd I) have been grown which are suitable for high resolution x-ray diffraction studies. Tetragonal crystals grow as square bipyramids from ammonium sulfate and Tris buffer using a temperature gradient. The space group is P41212 (or P43212) with a = 55.3, c = 95.9 A and 1 molecule/asymmetric unit. Triclinic crystals grow as plates or laths from ammonium sulfate and phosphate buffer at constant temperature. The space group is P1 with a = 46.8, b = 58.7, c = 64.3 A, alpha = = 105 degrees 05 min, beta = 82 degrees 30 min, gamma = 110 degrees 30 min and 4 or 5 molecules/unit cell. Both crystal forms are stable to x-ray irradiation and diffract beyond 3.0 A resolution.


Peptide maps of the myosin isoenzymes of Acanthamoeba castellanii.

Extracts of Acanthamoeba castellanii contain four myosin-like ATPases (Maruta, H., Gadasi, H., Collins, J.H., and Korn, E.D. (1979) J. Biol. Chem. 254, 3624-3630): double-headed Acanthamoeba myosin II and single-headed Acanthamoeba myosins IA, IB, and IC, which have heavy chains of 170,000, 130,000, 125,000, and 130,000 daltons, respectively, as well as different light chains. In the accompanying paper, evidence is presented that suggests that Acanthamoeba myosin IC is the same molecule as Acanthamoeba myosin IA plus a regulatory 20,000-dalton peptide. This conclusion is confirmed by the identity of the peptide maps obtained by limited proteolysis of the heavy chains of Acanthamoeba myosins IA and IC by Staphylococcus aureus V8 protease. However, peptide maps of the heavy chains of Acanthamoeba myosins IA, IB, and II obtained by limited proteolysis by the Staphylococcus protease and chymotrypsin and by chemical cleavage by cyanogen bromide and cyanylation have few, if any, peptides in common. From this evidence, and the enzymatic and subunit data in the accompanying paper, it is concluded that the three Acanthamoeba myosin isoenzymes, IA (IC), IB, and II, are products of different genes.


Isolation of estrogen receptor in complex with a discrete nuclear subfraction from hen oviduct.

A nuclear subfraction containing bound estrogen receptor in presumed complex with its nuclear acceptor site has been partially purified from hen oviduct. Sucrose density gradient ultracentrifugation was used to separate mechanically sheared chromatin (i.e. lysed nuclei) into several fractions which differed in protein to DNA ratio as well as in vitro template activity. Gradient fractions were then examined for the presence of bound estrogen receptors. Care was taken to use physiological ionic strength buffers when preparing nuclei since the number of estrogen receptors per nucleus decreased from 5600 to 1600 when nuclei prepared in low ionic strength (mu = 0.013 M) were compared with nuclei prepared in physiological ionic strength (mu = 0.2 M). [3H]Estradiol was introduced into nuclear estrogen receptors by exposing minced oviduct to labeled hormone in tissue culture or by exchanging nuclear estrogen receptor complexes formed in vivo with labeled hormone. In all cases, receptor was found in a fast sedimenting nuclear subfraction of low in vitro template activity. Sodium dodecyl sulfate-gel electrophoresis revealed no differences between proteins from receptor-containing and slower sedimenting fractions. Hybrdization experiments using a cDNA probe made from ovalbumin mRNA indicated no enrichment of this gene in DNA from receptor-containing nuclear material. Salt-extracted nuclear estrogen receptor was shown to partially aggregate to fast sedimenting species of heterogeneous size when sedimented in gradients containing low salt concentrations. Bound receptors were distinguished from such receptor aggregates using a novel electrophoresis technique. In addition, receptor aggregates could be disrupted in high salt, while bound receptors were resistant to this treatment. The number of exchangeable nuclear estrogen receptors in immature chicks given secondary estrogen stimulation was compared with birds that had been withdrawn from hormone. The number of receptors per nucleus was shown to be higher in animals given secondary stimulation, and these receptors were associated exclusively with fast sedimenting nuclear material.


Detergent properties of water-soluble choline phosphatides. Selective solubilization of acyl-CoA:lysolecithin acyltransferase from thymocyte plasma membranes.

Several analogs of lysolecithin were found to solubilize human erythrocyte ghosts comparably or even better than other detergents. Derivatives with aliphatic chains of 12 to 14 carbons were most effective. The phosphorylcholine detergents apparently possess low protein-denaturing properties, since they, for the first time, allowed the solubilization of enzymatically active acyl-CoA:lysolecithin acyltransferase from thymocyte plasma membranes. The solubilized enzyme was not sedimented at 177,000 x g for 60 min and penetrated into Sepharose 6B gels. Low detergent concentration resulted in a selective extraction of the acyltransferase (about 70%) as compared to alkaline phosphatase, nucleotide pyrophosphatase, gamma-glutamyltransferase or Mg2+-ATPase (30 to 40%). The selectivity was reflected in sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns of soluble and sedimentable membrane fractions; three bands of approximately 53, 84, and 94 x 10(3) daltons were enriched in the supernatants, whereas one band of about 68 x 10(3) daltons was concentrated in the pellet. The preferential extraction of acyltransferase may be related to particularly high affinity of lysolecithin analogs for this enzyme, which at higher concentrations was competitively inhibited by these detergents. The inhibitor constants ranged from 1400 micron for the C10 analog (ET-10-H) to 80 micron for the compound with 16 carbons (ET-16-H) per aliphatic chain.


Reaction of vaginal tissue of rabbits to inserted sponges made of various materials.

Sponges of the same size made of collagen (CS), polyurethane (PU), polyvinylalcohol (PVA) and acetylcellulose (AC) were inserted for 10 days in the vaginas of 22 rabbits. Light and scanning electron microscopy of the vaginal wall and its mucosal lining showed signs of cytotoxicity only with PU and AC while CS and PVA picture did not differ from sham controls. In order to explain the reasons for the toxic effects, all sponges were extracted into aqueous or organic solvent media and analyzed by gas liquid chromatography. Only several minute peaks in organic solvents were found. Extracts of all sponges tested for cytotoxicity in fibroblast cultures showed significant inhibition of H3-thymidine uptake. Nevertheless, extract of collagen sponge was significantly less cytotoxic than the extracts of all other sponges.


Implant site infection rates with porous and dense materials.

The infection rate of implant sites bearing porous and dense implants was studied in mice. In the first model (acute infection) the mice were injected with Staphylococcus aureus subcutaneously at the implant site at the time of implantation. In the second (chronic) model the implants were left in place for four weeks for encapsulation or invasion to occur and then the organisms were inoculated. In the acute model the infection rate with the porous materials was greater. In the chronic model after tissue invasion the infection rate with the dense materials was greater. This supports the hypothesis that microorganisms can evade host defense mechanisms if they enter the pores of the implant before tissue invasion, but that once the implant is invaded with host tissue the bacteria are less apt to establish infection.


A method for toxicity screening of biomaterials using cells cultured on millipore filters.

In the present paper a tissue culture technique is described whereby the toxicity of setting and solid materials may be evaluated. A cell monolayer was established on a millipore filter which was placed on an agar medium, cell side down. Test specimens were placed on top of the millipore filter and were allowed to influence the cells through the filter for two hours. The cell reaction was assessed by incubating the cells, still adherent to the filter, for the demonstration of succinate dehydrogenase activity. Materials with a cytotoxic effect caused a zone of inhibited enzyme activity in the cell-material contact area. The filters were examined macroscopically and scores from 0 to 3 were given to grade the severity of the cell response. Unset and set silicate cement, zinc phosphate cement and an acrylic resin were tested. The results obtained were consistent and in accordance with those of previous reports. The method was simple and rapid and appeared suitable for the assay of larger test series.


A study of the reaction of human tissue to proplast.

The femoral stems of Thompson prostheses coated with a polytetrafluoroethylene/carbon fiber composite (proplast) were studied using conventional histological examination, scanning electron microscopy and electron probe microanalysis in "successful" firm implants and in a "loose" clinically unsuccessful implant. Ingrowth was found throughout the coatings of the successful prostheses. In the most firmly fixed prosthesis the ingrowth consisted of fibrous tissue with abundant giant cells; however, no bone ingrowth was detected. There was less composite pore infilling in the unsuccessful implant. From both clinical, radiological and the studies described above, it is concluded that fibrous tissue ingrowth was a secondary stabilizing phenomenon in the proplast-coated prostheses studied.


Monomer release from methacrylate bone cements during simulated in vivo polymerization.

The release of monomer from methylmethacrylate bone cements was studied during immersion in an aqueous environment intended to simulate in vivo polymerization of the material. Monomer release from disk-shaped specimens into an aqueous environment was assayed by gas chromatography. The simulated intracorporal polymerization was carried out under a variety of conditions intended to encompass possible clinical variables. The majority of monomer release occurred within the first 15 min of immersion. Under conditions generally recommended for commercial cements the release into aqueous media was always less than 3% of the total monomer weight. Clinically feasible options of delaying the time from onset of mixing of the cement to insertion into the host resulted in only a 0.7 wt % difference in the amount of released monomer. Measurements for a variety of monomer/powder ratios demonstrated a minimum in the amount of released monomer at a ratio of about 0.4 ml/g. In terms of unit area covered, thin specimens released less monomer than thick specimens.


A correlation between abrasion resistance and other properties of some acrylic resins used in dentistry.

This investigation studies the relationship of hardness, elastic modulus and scratch width as dependent variables to the abrasion resistance of twenty-three dental acrylic resins. The multiple correlation R, when all three variables are used as predictors, is 0.727. Because of the significant intercorrelations between the variables themselves a stepwise multiple regression analysis showed hardness as a redundant variable. Abrasive wear can be estimated from the following equation  Abrasive wear = 806.1 - 0.1498 modulus + 0.681 scratch width (R = 0.725; standard deviation of estimate +/- 50.8)  The deletion of scratch width does not appreciably reduce the standard deviation of the estimate: Abrasive wear = 1063.4 - 0.2055 modulus (r = 0.683; standard deviation of estimate +/- 50.3)  The method of curing the specimens conformed to the respective manufacturers' instructions. Abrasion and scratch tests were performed using methods developed by the authors and previously described in the literature, whereas the hardness and elastic modulus results were devised from standard test procedures. Further research is currently in progress to improve the predictive power of abrasion resistance with additional new variables.


In vitro corrosion of Ti-6Al-4V and type 316L stainless steel when galvanically coupled with carbon.

In vitro corrosion experiments were conducted employing potentiostatic polarization techniques, a saline environment and candidate biomaterial alloy/carbon combinations. Corrosion currents and potentials of carbon/metal couples were predicted by mixed-potential theory utilizing the polarization curves generated. The alloys examined were annealed ELI grade Ti-6A1-4V and cold-worked 316L stainless steel while the types of carbon examined were LTI pyrolytic carbon and vapor-deposited carbon. It was determined that galvanic couples of carbon to cold-worked 316L stainless steel with carbon/metal area ratios of 10:1 to 100:1 produced coupled corrosion potentials in the range of the observed breakdown potential of the stainless steel. It was therefore predicted that localized corrosion in the form of pitting could occur on the cold-worked stainless steel when coupled to carbon with area ratios of 10:1 or greater. The titanium alloy did not exhibit a breakdown potential up to a potential of 1.2 V. Therefore, accelerated corrosion was not predicted for the titanium alloy to carbon galvanic couples under these experimental conditions. Direct carbon/alloy coupling experiments were conducted to verify the corrosion currents and potentials predicted from mixed-potential theory and polarization curve analysis. The experimental and theoretical values showed good agreement.


Application of Auger electron spectroscopy for surface chemical analysis of Avcothane.

The effect of the exposure to air or to the substrate during the solvent casting process on the surface chemical composition of Avcothane, a blood compatible biomaterial, was studied by employing Auger electron spectroscopy. The surface layer of 10-15A thickness was analyzed without sputtering, but for the studies probing a deeper layer, argon ion sputtering at a low enough voltage to prevent artifacts was utilized. It is found that the air facing surface which is the blood contact surface contains a greater amount of silicone polymer and a much lower amount of the urethane hard segment in the first 10-15A-deep layer than in the comparably thick layer of the substrate surface. However, the depth-composition profile obtained by sputtering indicate that, probably at a deeper depth, the chemical compositions in terms of silicone polymer and hard segment is comparable both in the air side and the substrate side.


Direct anchorage of Al2O3-ceramic hip components: three years of clinical experience and results of further animal studies.

The biocompatibility of high-purity dense Al2O3-ceramics had been shown to open the possibility of direct cement-free anchorage of joint endoprostheses. Three years of clinical experience with ceramic-metal composite total hip prostheses confirm the biomechanical design criteria used for the acetabular components. They also allow for additional conclusions regarding the reaction of bone tissue towards a bioinert implant. Further research activities are directed towards a solution for biomechanically stable anchorage of the femoral component of hip prostheses.


Tissue reaction to ceramic implant material.

The biocompatibility of alumina ceramic was tested by means of macrophage cultures, intraperitoneal (i.p.) and intramuscular (i.m.) application of powdered particles in rats, and by implantation of solid samples in the paravertebral muscles and the condylus femur. No acute cytotoxicity was found in macrophage cultures. The i.p. and i.m. application of powdered particles in the beginning showed a granulocytic reaction, later followed by a histiocytic reaction. Also, the morphological changes in the organs of reticulo histiocytic system (RHS) are shown. In the solid samples implantation, the fibrogenetic stimulus is measured by morphological analysis of the connective tissue membrane around the sample. The importance of the individual cell observation by transmission-electron microscope (TEM) examination is evidenced. The experimental results are compared to the environmental reaction of smaller animal-adapted prostheses and prostheses having been implanted in human patients. Good biocompatibility is confirmed by these investigations; also regarding central position of the macrophages, the environmental reaction due to implant material is shown.


Investigations with bioactivated polymethylmethacrylates.

Compound bone cement on a PMMA base with an additive of bioactive glass ceramic particles in different portions and different particle sizes are tested in animal experiments. The tissue reactions to extracorporal polymerized specimens and to in situ polymerized specimens are observed. The experiments with an implantation period up to six months demonstrate a tight bonding between the newly formed osseous tissue and the glass ceramic particles at the interface. The inflammatory reactions in the vicinity of the implant are small. It is the objective of the investigations to improve the adherance of the bone cement at the interface to achieve a more durable anchorage of bone cement in the tissue.


ESCA studies of surface chemical composition of segmented polyurethanes.

Surface chemical analysis of two commercially available polyurethanes, i.e., Avcothane and Biomer was carried out by electron spectroscopy for chemical analysis (ESCA). The depth which is subject to analysis is in the range of 50-100 A. The variables studied in this study are the difference in exposure to air or to the mold substrate during the solvent casting process. Model compounds such as a pure polydimethylsiloxane, polyether soft segment and hard segment copolymer were used to identify and assign various ESCA peaks. The air facing surface of Avcothane which is the blood contacting surface is found to be covered mostly with polydimethylsiloxane polymer, with a small amount of polyether soft segment mixed with silicone. Therefore, the hard segment of the polyurethanes is hidden beneath the blood contact surface in Avcothane. In Biomer films, the air facing surface contains a greater concentration of polyether soft segment than the substrate surface. These results are consistent with our previous results obtained by Fourier transform IR internal reflection and Auger electron spectroscopy.


Surface charge in foreign body carcinogenesis.

The importance of surface charge in foreign body carcinogenesis was evaluated by implanting in C3H/HeJ male mice, bipolar polystyrene thermoelectrets formed in variously charged electrical fields. Charged electrets had tumor rates similar to control groups. The cumulative probability of tumor development was highest in the charged electret group being 0.58 at 133 weeks after implantation. The tumor rate for all charged electrets was 27% as compared to 17% and 6% for the control groups. The latent period of tumor induction varied little between groups and averaged approximately 700 days. No conclusions regarding the tumorigenic effect of electropositive versus electronegative sides of the electret were made although the majority of tumors arose on the electronegative (body) side of the electrets. An occasional tumor (2/25) arose on both sides of a single electret. The antigenicities of tumors tested by excise and challenge techniques were weak. The immunologic relationship between top and bottom growing tumors on a single electret could not be adequately determined because of the weak antigenicity.


Thermally induced time dependence of mechanical properties in biomedical grade polyurethanes.

The time dependence of the mechanical properties of segmented urethanes as well as urethane-urea systems were monitored after the materials had been given a short thermal treatment followed by rapid cooling. Both linear and crosslinked materials were studied but the major focus was on many of the common biomedical grade urethanes. As had been noted in earlier studies on nonmedical segmented urethanes from this laboratory, many of the biomedical grade materials also showed time-dependent changes in mechanical properties that can be directly related to time-dependent changes in the degree of domain structure (microphase separation) that may occur in these segmented copolymers. Interestingly, those systems possessing significant amounts of urea linkage show little or no significant time-dependent changes in structure or properties following thermal treatment. The effect of chemical cross-linking can also influence the domain formation process and its thermal stability. The ramifications of these time dependent effects may have bearing on the biomaterial applications of segmented urethane polymers.


In vitro evaluation of hemolytic and cell culture toxicity potential of residual ethylene oxide in selected medical materials.

The hemolytic potential of pure ethylene oxide in solution was evaluated as a function of initial ethylene oxide concentration in three test systems, diluted whole blood in isotonic saline, erythrocytes washed and resuspended in isotonic saline, and erythrocytes washed and resuspended in isotonic phosphate buffer. Concentrations of 2 mg/ml (2000 ppm) were necessary before cell lysis was observed in either of the isotonic saline systems. This value increased to 10 mg/ml 10,000 ppm) in the isotonic buffer system. Efforts have been made to correlate the hemolysis and cell culture toxicity of residual ethylene oxide in five medical materials to the toxicity of pure ethylene oxide. Only materials exhibiting a low order of inherent toxicity showed any correlation. In poly(vinyl chloride) tubing containing 1.8 and 2.1 mg ethylene oxide per gram of material, a small amount of toxicity was seen in the cell culture system but toxicity was absent in the hemolysis test.


Use of fracture mechanics theory in lifetime predictions for alumina and bioglass-coated alumina.

The fatigue behavior of alumina and bioglass-coated alumina was determined in air and biological test environments by the dynamic fatigue test technique in which strength is measured as a function of stressing rate. The good correlation found between the test data and fracture mechanics theory indicates that fatigue failure is controlled by the slow crack growth of preexisting flaws and that fracture mechanics theory can be used in making failure predictions for alumina and bioglass-coated alumina in biological environments. Thus, it is believed that lifetime predictions can be made for ceramic implants on the basis of short-term test data utilizing fracture mechanics principles.


Solution treatment behavior of Co-Cr-Mo alloy.

Current practice in the manufacture of Co-Cr-Mo alloy total hip prostheses is the use of a solution treatment to increase the ductility of the as-cast alloy. This study is concerned with the reactions encountered during solution treatment at temperatures between 1165-1270 degrees C. These reactions, including incipient melting, a carbide transformation from M23C6 to M6C and sigma-phase formation, have been examined using both qualitative and quantitative metallographic techniques, and are shown to influence the production of a single phase microstructure. As a result, an optimum temperature for solution treatment of 1220 degrees C has been determined. It is further proposed that a reduction in the carbon content of this alloy would improve its solution treatment behavior.


In vitro deformation failure analysis of dental amalgams.

The in vitro deformation failure behavior of the conventional and the recent high copper dental amalgams is studied under different strain rates. The conventional silver-tin amalgams exhibited significant slow compressive flow at low strain rates, but failed catastrophically at the higher loading rates. On the other hand, amalgams containing highest copper contents showed no compressive flow and failed catastrophically at all the loading rates. The slow compressive flow in the conventional dental amalgams indicate that dislocations may play an important role in the deformation process of the amalgams at the lower strain rates.


Bioevaluation of plasma polymerized films in skeletal muscle.

Plasma polymerized ethylene (PPE), styrene (PPS), and chlorotrifluoroethylene (PPCTFE) were synthesized by exposing the monomeric gases to an inductively coupled radio frequency "glow-discharge" field. The polymer films were deposited on poly(dimethyl) siloxane (medical grade Silastic), which was then surgically implanted in rat paravertebral muscle for periods up to 84 weeks. The biocompatibility of the plasma deposited films and uncoated Silastic was evaluated by qualitative (graded inflammatory cell response) and quantitative (connnective tissue capsule thickness) techniques as a function of time. The morphological features of the connective tissue capsule and the plasma polymerized films were examined by SEM after 75 weeks of implantation. Results showed that the acute inflammatory cell migration around PPS and PPCTFE was at a maximum in 2 weeks, decaying to control levels in 4 to 8 weeks. The PPE response was judged as less than the control response up to 4 weeks. After 8 weeks no qualitative difference could be detected between the plasma polymerized films and Silastic. On the other hand, a quantifiable change in fibrous capsule response as a function of time and material was noted until 24 weeks. From these data we conclude that these types of films do not elicit an untoward foreign body reaction at a skeletal muscle implant site in rats.


Thrombus formation and microaggregate removal during extracorporeal membrane oxygenation.

Contemporary microporous membrane oxygenators have adequate gas transfer capacity and even prolonged oxygenation is relatively atraumatic to the blood elements. However, even with adequate heparinization, thrombus formation still takes place, albeit to a lesser degree than in direct blood-gas contact devices. In this work, scanning electron microscopy of the dissected devices in the extracorporeal circuit was performed on devices used during four aorto-coronary bypasses and two cardiac valve replacements. Membrane surfaces remained free of major deposits although thrombotic material could still be observed in parts of the oxygenators and the filters. Blood filtration from the cardiotomy reservoir may be more critical as it removes surgical debris and cells injured by suction which appear to enhance thrombus formation within the oxygenator. The return line arterial filter appears more useful as a bubble remover; its value appears much diminished as microemboli do not leave the device in large quantities.


Epiphyseal stapling for angular deformity at the knee.

Fifty six patients with angular deformities of eighty-two knees were treated with epiphyseal stapling between 1954 and 1973 and followed until maturity. There were sixty-four knock-knees and eighteen bowlegs. In twelve patients with concurrent leg-length discrepancies, long legs were stapled asymmetrically. The deformities were allowed to overcorrect before the staples were removed, but the rebound phenomenon occurred in twenty-two patients with thirty-five deformities. In older children the staples were taken out when the legs looked straight. Exaggerated physiological deformities may correct spontaneously. They should not be stapled before the skeletal age of eleven in girls and twelve in boys. Secondary deformities are corrected earlier. There were no significant complications. Ten revisions of staples were necessary because of extrusion or shifting. The results were satisfactory or improved in 87 per cent of the deformities. When it is indicated epiphyseal stapling is a safe and effective method of correcting angular deformity at the knee in growing children.


Distal iliotibial-band transfer for anterolateral rotatory instability of the knee.

An operative procedure has been developed to prevent anterior subluxation of the proximal end of the tibia in patients with anterolateral rotatory instability of the knee. The results of this procedure in eighteen consecutive patients are reported. Ten (55.6 per cent) had had prior surgery on the involved knee. All patients had an additional pathological lesion and all were incapacitated for their sports prior to reconstruction. The shortest follow-up in this series was thirty-one months and the longest, forty-four months. Forty-four per cent had an excellent result, participating in sports without signs or symptoms, and 39 per cent had a good result, participating but with some modest problem. In 17 per cent the results were unsatisfactory.


Marmor modular knee in unicompartmental disease. Minimum four-year follow-up.

Fifty-six consecutive knees were operated on for single compartment disease using the Marmor modular knee with a minimum follow-up of four years. The information obtained indicates that single compartment replacement is valuable in restoring function and relieving pain in a high percentage of patients. There was no evidence of late degeneration of the successful results at the time of writing. No difference in the results obtained with medial or lateral compartment replacement has been noted. Degeneration of the compartment not operated on has not been a problem. Unicompartmental replacement is an excellent procedure in the elderly patient who has osteoarthritis of the knee with varus or valgus deformity.


Degenerative arthritis of the ankle secondary to long-standing lateral ligament instability.

Long-standing lateral ligament instability of the ankle results in unbalanced loading of the medial joint space and the possible development of degenerative arthritis. Thirty-six patients who had had lateral ankle instability for at least ten years and complaints of increasing ankle pain evidence degenerative changes of the articular cartilage over the medial half of the talar and tibial surfaces of the ankle joint. These changes were minimally apparent on roentgenograms unless weight-bearing roentgenograms were made, but arthroscopy of the joint accurately revealed the extent of degeneration. After reconstruction of the lateral ankle ligaments, fourteen of twenty-two patients with mild to moderate arthritic changes showed both symptomatic improvement and demonstrable widening of the medial joint space on weight-bearing roentgenograms. Four of five patients with severe degenerative arthritis subsequently had a total ankle replacement.


Pressures generated in the thigh muscles and under the thigh cast of an uninjured subject wearing a cast-brace.

Intrinsic pressures within the thigh muscles of a normal subject were recorded with the subject in five different postures before and after application of a cast-brace. The extrinsic pressures between the plaster cast and the underlying skin also were recorded. The intrinsic muscle pressures were significantly increased when the cast-brace was applied.


Pressure recordings in patients with femoral fractures in cast-braces and suggestions for treatment.

Five patients with femoral-shaft fractures were treated by cast-brace application and early ambulation. As fracture healing progressed, pressures between the thigh and the cast were recorded with the patients lying still, contracting the quadriceps while lying down, and in four weight-bearing postures. Control results were gained by application of a second cast-brace to three of the patients when they had recovered completely. Resting pressures averaging sixteen millimeters of mercury were recorded under the whole cast. Much higher values were recorded under the proximal two-thirds of the cast, and these increased as healing proceeded. Removal of the hip hinge, thereby eliminating fixed abduction, reduced pressure recordings significantly.


Risks of exposure to X-rays in patients undergoing long-term treatment for scoliosis.

Thirteen healthy teenage girls with idiopathic adolescent scoliosis were studied using multiple thermoluminescent dosimeters while undergoing standard diagnostic roentgenograms. Average organ doses for each anteroposterior and lateral examination were calculated for bone marrow, gastrointestinal tract, lungs, breast tissue, and gonads. Given an average of twenty-two roentgenograms over a three-year Milwaukee brace-treatment program, the increase in organ carcinogenic risk due to x-ray radiation ranged from 3.4 to fifteen per million (1.3 per cent to 7.5 per cent), except for breast tissue which increased from 140 to 290 per million (110 per cent). Using posteroanterior rather than anteroposterior exposures reduced the increased risk to 5.3 per million (3.8 per cent). The genetic risks of scoliosis roentgenographic studies were considered to be negligible, especially with gonadal shielding and infrequent roentgenograms made every three to four months. Good technique and judicious ordering of roentgenograms added significantly to the safety of the patient.


Closed biopsy of musculoskeletal lesions.

Five hundred and thirty-one closed biopsies have been done in our general hospital since 1967. Four hundred and eighty-four were for lesions of bone and forty-seven were for soft-tissue lesions. More than half of the lesions were infections or nonspecifically reactive. The procedure was done under local anesthesia in 73 per cent and roentgenographic or image-intensifier control was generally required. The Craig needle was used for cancellous bone near vital structures; the Michele trephine, for cortical or sclerotic bone at a distance from vital structures; and a special needle was used for soft tissue. Closed biopsy provided an adequate specimen that was accurately diagnosed in 66 per cent of bone lesions and in 76 per cent of soft-tissue lesions. This compared favorably with both aspiration and open-biopsy success rates reported by others, and was accompanied by a 1 per cent complication rate, mostly neural and mostly in association with vertebral lesions.


Overgrowth of the femur following fractures in children: influence of handedness.

Handedness was a more important factor in the amount of overgrowth following fractures of the femoral shaft in children in the present study than factors previously investigated. The lower limbs were measured and handedness was recorded in 112 children who had sustained their fractures fourteen to 101 months (mean, fifty-six months) before the study was undertaken. Fifty-two of these patients also had scanograms. The average overgrowth for all injured limbs was ten millimeters. The difference in the amount of overgrowth which was observed was this: when the fracture was on the same side as the dominant hand, the limb overgrew an average of eight millimeters, compared with fourteen millimeters when the fracture was on the side opposite the patient's dominant hand. This difference for the scanogram group was statistically significant (p less than 0.05). Overgrowth was significantly inhibited by overriding of fracture fragments and was enhanced by distraction. The age of the patient and the type and location of the fracture did not significantly affect overgrowth.


Experience with the McAtee olecranon device in olecranon fractures.

Treatment of olecranon fractures by prolonged immobilization often results in limited elbow motion. With the use of a compression screw apparatus, anatomical reduction was obtainable, and only a short period of immobilization was needed. In a series of eleven fractures there were no non-unions and an average decrease in elbow range of motion of only 8 degrees.


Gunshot wounds of the spine: the effects of laminectomy.

In a review of 185 patients with gunshot wounds of the spine from low-velocity missiles, 106 were found to have a complete lesion and seventy-nine, an incomplete lesion. Fifty-six patients with complete lesions underwent laminectomy and only one had a partial (sensory) return of function. The fifty patients with complete lesions who had no laminectomy also had no spontaneous improvement. There were forty-five patients with incomplete lesions who had laminectomy and thirty-two (71 per cent) of them showed measurable improvement. For comparison, thirty-four patients with incomplete lesions had no operative treatment and in twenty-six (76.5 per cent) there was some spontaneous return of neural function. Four wound infections and six spinal fistulae developed in the operative group (a complication rate of 10 per cent). Spinal instability developed in six patients because of the laminectomies.


Lipofibroma of the median nerve in the palm and digits of the hand.

Lipofibroma of the median nerve or its cutaneous branches is a rare benign tumor. The diagnosis is usually made at surgical exploration of a mass in the distal part of the forearm, the wrist, the palm, or the digits of the hand, which may be asymptomatic or associated with symptoms of carpal-tunnel syndrome. The diagnosis should be made when exploration reveals fusiform enlargement of a segment of the median nerve or its cutaneous branches without hypertrophy of the regional tissues. The tumor is limited to within the epineurial sheath, which is intact, shiny, orange-yellow, firm, thick, and non-resilient to dissection. The nerve tumor does not infiltrate the surrounding tissues nor do the surrounding tissues infiltrate the nerve. If the epineurium is opened, the nerve fibers are found to be inseparably infiltrated by fibrous and fatty tissues. Histologically, these are of epineurial, perineurial, and endoneurial origin. A forzen-section biopsy of a palmar cutaneous branch is suggested to confirm the diagnosis. Once the diagnosis is confirmed, the treatment should be limited to release of the fascia over the involved nerve. The tumorous part of the median nerve was partly or completely excised in seven of twenty-six cases reviewed in the literature and this report. It is to emphasize a conservative approach when such a tumor of the median nerve is encountered at surgery that we describe two more cases.


The role of the musculature in injuries to the medial collateral ligament.

With a knee-testing device we measured the valgus stiffness of the medial musculoligamentous complex of the knee in five volunteers. Tests were done with the muscles quiescent and with contraction of the sartorius and vastus medialis. Contraction of those muscles substantially increased the valgus stiffness. In eight subjects the voluntary reaction times were measured. With either a visual or a tactile impulse for prophylactic muscle contraction, the muscles acted too slowly to augment the stiffness of the knee so as to prevent injury. In fifty-one volunteers we applied the maximum torque to the leg, just short of eliciting pain, and showed that even then the muscle contraction would occur too late to protect the knee in typical sports situations.


A microbiological in-use comparison of surgical hand-washing agents.

Seven different surgical hand-scrub agents (one triclosan compound, two hexachlorophene compounds, and four iodophors) were evaluated under in-use conditions by five persons for efficacy in degerming the hands and forearms prior to performing a total of 215 total hip arthroplasties. With all of the compounds tested there was a significant reduction (p less than or equal to 0.001) of indigenous skin microflora from prescrub levels at both the post-scrub and postoperative points. The two hexachlorophene compounds in general revealed a bacteriostatic effect whereas the triclosan compound and the four iodophors did not. A hexachlorophene compound applied as a foam demonstrated excellent bacteriocidal and bacteriostatic action, was less time-consuming and easier to use than compounds applied as scrubs, and did not alter a low (0.47 per cent) in-use infection rate over a period of three years.


Metabolic activity of articular cartilage in osteoarthritis. An in vitro study.

Biochemical changes and in vitro rates of glycosaminoglycan synthesis were studied in thirty-seven samples of human articular cartilage from nineteen osteoarthritic and four normal control patients who were fifty to seventy-five years old. The samples were compared on the basis of histological grade of the arthritis, and subgroups based on the duration of disease, synovial pathological changes, joint studied, and sex were also compared. The osteoarthritic samples showed a progressive loss of glycosaminoglycans in the cartilage as the histological grade increased. In the early stages of the disease there was an increase in the chondroitin sulphate content as well as in the rate of glycosaminoglycan synthesis in several cases when the values for the osteoarthritic articular-cartilage samples were compared with those for the age-matched controls. In the late stages there was a progressive decrease in the rate of glycosaminoglycan synthesis and a relative decrease in chrondroitin sulphate synthesis compared with keratan sulphate synthesis, and these decreases were highly correlated with the histological grade.


Supracondylar fractures of the humerus. A comparative study of Dunlop's traction versus percutaneous pinning.

A retrospective comparative study was done of two groups of patients with displaced supracondylar fractures of the humerus. The patients in the first group were treated with Dunlop's traction, while those in the second group were treated by percutaneous pin fixation. There were thirty-six patients in the group treated with Dunlop's traction, of whom twenty-seven were seen in follow-up with an average time of 2.7 years. Twenty-eight patients were in the group treated with pin fixation, of whom twenty were seen in follow-up with an average time of 2.9 years. In each case the chart and roentgenograms were reviewed and the patient was examined. The results showed a 33 per cent incidence of cubitus varus (so-called gunstock deformity) in the patients treated with Dunlop's traction as compared with 5 per cent in those pinned percutaneously. The range of elbow motion was also slightly better in the group treated with pin fixation. Furthermore, the costs and hospital stays were significantly less in those treated by pinning. Complications in both groups were few.


Radiologic consultation to a remote Canadian hospital using Hermes spacecraft.

Access to medical services in north Canada is limited by geography, climate, communication and transportation. A geostationary spacecraft, Hermes, was used to provide dependable, high-quality communication between a remote nursing station, a base hospital and a health science centre. Teleradiology formed an important component of the telemedicine services. Remote supervision of radiography and fluoroscopy was made possible; consultation services were shown to be 90% effective.


A modular computer system for radiologists.

A computer system was developed for two private radiology offices, consisting of six modular components, a history file, registration file, assisted reporting module, appointment management module, accounting module and statistical module. Effectiveness and efficiency of patient care have been increased substantially.


Flow-chart for sequential cholecystography.

A protocol designed to integrate oral cholecystography with ultrasonography and scintiscanning of the gallbladder is presented. The planned use of these modalities will permit a 95% clinically useful assessment on a single visit to the x-ray department.


The ellipse sign--an aid in the diagnosis of acute ulcers.

When a persistent collection of barium is seen during a radiographic examination of the upper gastrointestinal tract, differentiation of acute ulceration from non-ulcerating entities (e.g. diverticulum, pseudodiverticulum, residual deformity of surgical intervention) is sometimes difficult. When, however, the persistent collection of barium has an ellipitical configuration, the orientation of the long axis of the ellipse can be an indicator of the nature of the pathologic process. If the long axis is perpendicular to the lumen, the collection represents a deformity without acute ulceration. If the long axis is parallel to the lumen, the collection represents an acute ulceration.


Neonatal skeletal fractures. Birth trauma or child abuse?

When a fracture is discovered in a newborn infant, it is important to decide whether it occurred at birth or after birth. Calcification around the fracture site gives a useful estimate of the age of the fracture. We reviewed films of 23 patients with fractures resulting from delivery. The fractures occurred at three different sites: the clavicle, the humerus, and the femur. Calcification could be seen as early as seven days after birth and was absent for as long as 11 days after birth. Six of seven femoral fractures occurred in infants with neuromuscular problems. Fracture at an unusual site or absence of calcification after 11 days should alert the radiologist to the possibility of abuse.


Giant-cell tumor of the sacrum. Clinical and radiologic features in 13 patients.

Thirteen patients were found to have giant-cell tumors during a study of 91 primary tumors of the sacrum. This tumor was second only to the chordoma in incidence. Giant-cell tumor is by far the commonest benign lesion of the sarcrum, yet it has a bad prognosis. Recurrences occurred in seven patients and five died of disease or a complication. All were histologically benign when first seen, but one developed a malignant giant-cell tumor and died within two years, and one developed a radiation-induced sarcoma 10 years following treatment. Computed tomography in two recent patients proved to be the most valuable single examination. Arteriography is helpful in showing the degree of vascularity of the tumor and the exact position of the large vessels, particularly important when surgical resection is planned.


Coarctation of the aorta: additional signs.

Rib notching and the figure-three configuration and the most often cited signs of coarctation of the thoracic aorta in the adult. In our experience, these so-called classic signs are absent in many patients. Abnormalities of the ascending aorta, aortic arch, and superior mediastinum are also major findings and indeed may be the only findings in coarctation. This has not been sufficiently emphasized in standard radiology texts. In order to elucidate these points, we reviewed the chest radiographs of 13 patients with adult-type coarctation of the aorta presenting to the Jewish General Hospital over a 10-year period. In addition, the chest radiographic findings of five patients with pseudocoarctation were compared to those of true coarctation.


Arterial dissection with use of catheter needle in retrograde femoral arteriography.

A retrospective study of 82 cases of peripheral vascular occlusive disease examined by retrograde femoral arteriography with a catheter needle technique showed a 6% incidence of retrograde arterial wall dissection involving the iliac arteries and the aorta. In one patient, the dissection re-entered the abdominal aorta near the renal arteries, producing an iatrogenic chronic dissection. The others did not demonstrate any permanent side effects. In 1974, in view of the appreciable risk in the use of a catheter needle, the technique was changed to percutaneous femoral catheterization of the abdominal aorta using a catheter with multiple side holes. No further cases of iatrogenic aortic dissection were observed. A veriety of mechanisms may have been responsible for the dissections.


Lower urinary tract trauma.

Twenty-eight patients with lower urinary tract injuries were reviewed at Hôtel-Dieu de Montréal. Eighteen involved the urethra and ten involved the bladder. Pelvic rami fractures are the main cause of bladder rupture, including almost all cases of extraperitoneal bladder rupture. Pelvic fractures are also the main cause of posterior and bulbo-menbranous urethra rupture. Endoscopy and indwelling catheter insertions follow in importance. Rupture of the bladder can be either extraperitoneal (80%) or intraperitoneal (20%). Ruptures of the urethra involve mainly the posterior and bulbo-membranous segments of the urethra. Post-traumatic strictures nevertheless affect the anterior segment more commonly. In all suspected cases of injury involving the lower urinary tract, retrograde urethrography should be done first, followed by retrograde cystography if indicated. A good knowledge of the relationship of the anatomic compartments is essential to the assessment of communicating injury.


A modification of the radiology teaching conference.

Radiographs are placed on display the day before each teaching conference. This improves the discussion and enhances the learning experience.


Radiopaque suppositories mimicking bladder calculi.

A paraplegic patient presented with radiopaque suppositories mimicking recurrent calculi. An unnecessary cystotomy resulted.


Physiologic myometrial thickening: a source of confusion.

Focal myometrial thickening, thought to represent a focal transient myometrial contraction, was observed to disappear during the course of an ultrasonic examination.


Diastematomyelia in a geriatric patient.

The discovery of diastematomyelia in a geriatric patient is a rare occurrence. A 76-year-old woman with this entity was not diagnosed until she developed superimposed motor neuron disease.


Variations in x-ray exposures to patients.

X-ray exposures to patients were measured in 30 rooms in Toronto hospitals. For a given procedure, the total exposure for a satisfactory examination differed from one room to another by as much as a factor of 30, skin exposures reaching 90 R and more for barium enemas and barium meals. The factors primarily responsible for these large differences in exposure were fluoroscopic exposure rate (0.65-12 R/min) and time 1.5-12 min), kVp and filtration (8:1), choice of screen-film combination (6:1) and attenuation of table tops and phototimers (4:1). The increase by a factor of 5 in exposure of pelvic organs, when using beams directed AP instead of PA, requires that remote-controlled GI machines be used cautiously, particularly on women of childbearing age. It is also important that these machines have tables with low attenuation. The use in some rooms of minimal fluoroscopic exposure rates and 70 mm fluorography at total exposures of less than 5 R shows that radiographic examinations can be made virtually "safe" with modern, properly adjusted equipment.


Osteoid osteoma in cancellous bone.

Osteoid osteoma in cancellous bone lacks the usual osteoblastic reaction that accompanies the classical cortical or juxtacortical osteoid osteoma. Familiarity with this type of presentation should instigate the appropriate diagnostic steps, including nuclear medicine studies using pin-hole collimation, and thin tomographic cuts.


Hypogammaglobulinemia and nodular lymphoid hyperplasia of the gut.

A 34-year-old female had longstanding hypogammaglobulinemia associated with extensive nodular lymphoid hyperplasia (NLH) of the small bowel, colon and gallbladder. The characteristic appearance in double contrast barium studies should alert the radiologist to the possibility of hypogammaglobulinemia.


Urinoma diagnosed on a bone scan.

A case of urinoma diagnosed on a bone scan is described. The administration of radiotracers excreted by the kidney is a useful, non-invasive, uncomplicated diagnostic procedure when leakage from the urinary tract is suspected.


Plethysmography during aorto-iliac surgery.

Cardiac output, arterial and central venous pressures and calf blood flow were used to monitor patients undergoing abdominal aortic surgery. Measurement of calf blood flow by means of venous occlusion plethysmography showed that measurable blood flow to the legs persisted after clamping of the aorta in patients with occlusive aortoiliac lesions and that the hyperaemic response following release of the clamp was reduced. Arterial hypotension after clamp release was of the same time course as the hyperaemia. Leg blood flow measurement was a valuable monitoring procedure.


Uncommon congenital anomalies of the aorta.

Two cases of atypical localization of an aortic coarctation are described. One patient was a hypertensive girl with a hypoplastic type of coarctation in the descending aorta. After insertion of a bypass graft the hypertension disappeared. The other patient was a hypertensive girl with a total aplasia of the distal abdominal aorta and a hypoplasia of a right renal artery. After right nephrectomy the blood pressure became normal. There were no symptoms or signs of ischemia of the legs. This is the second case, known in literature, with a total aplasia of the abdominal aorta. Some general considerations about atypical coarctations are made.


Is there a place for external grafting of arterial aneurysms in selected patients?

External grafting of aortic and iliac artery aneurysms has been accomplished in 33 highly selected poor risk patients over a period of eight years. This experience demonstrated that external grafting of aneurysms is a technically demanding operative procedure which is accompanied by significant early and late morbidity. The technique does effectively reduce the occurrence rate of late rupture of aneurysms, however, at least for the period of observation of this study. Thus, while external grafting certainly is not generally applicable, the procedure may be used to advantage in highly selected situations, possibly including: 1. Long segment aneurysms of the thoracic or thoraco-abdominal aorta. 2. Aneurysms involving the renal arteries in poor risk patients. 3. As reinforcement for dilated arterial segments adjacent to sites of vascular anastomosis.


Chemical data: an essential tool in the regulation of drugs.

How the Bureau of Drugs laboratories and offices obtain chemical data from the scientific literature, from user complaints and product defect reporting systems, from the drug manufacturers, from analyses of drug samples collected from the market, and from analytical research are described. The chemical data thus educed have been used successfully in developing new analytical methods, in establishing better specifications of drug quality, in removing adulterated drugs from the marketplace, in successfully prosecuting purveyors of substandard drugs, and in general assuring that consumers are provided with safe and effective drugs of high quality.


Recurrences after Linton flap operation.

Out of 112 patients who had a Linton flap operation recurrences developed in 13.3%. The most common causes of it were the incomplete first operation and deep venous thrombosis developing in the follow up period.


Aneurysms in a branch of the renal artery in the hilus: obliteration by means of surgical clips.

An aneurysm in a branch of the renal artery within the hilus of a 44 year old woman was successfully obliterated without affecting the circulation in the parenchyma. The surgical treatment consisted of applying Scoville clips designed for intracranial aneurysms to the neck of the sac of the aneurysm. Postoperatively the patient has remained free of her previous hypertension for over four years.


Sources of chemical information used in antibiotic certification.

Because of a legislative mandate requiring the predistribution testing and certification of each batch of antibiotics produced for human use in the U.S.A., the National Center for Antibiotics Analysis (NCAA) must utilize a wide variety of techniques for establishing its official methods. Methods adapted from material submitted by the manufacturers in Forms 5 and 6, as well as from other sources, such as literature searches, the NCAA reprint collection, and cross reference file are described.


Infections and anastomotic false aneurysms in reconstructive vascular surgery.

The authors report their experiences in two kinds of late complications of direct reconstructive surgery: infections and anastomotic false aneurysms. Such complications occurred after operations calling for the use of alloplastic prostheses, with an incidence of 2.8% out of all other operations in which prosthesic grafts have been used. All the patients have undergone second surgery with good results in 16 cases out of 19 (84.3%), 1 patient underwent amputation (5.2%) and 2 patients, suffering for infected false aneurysms of the aorta, died (10.5%).


Complete replacement of the ascending aorta and the aortic valve with coronary reimplantation.

In 6 patients with cystic medial necrosis of the ascending aorta and the aortic root complete elective replacement of these structures with coronary reimplantation was performed. Two patients died from postoperative left ventricular failure, 4 patients survived and were hemodynamically unaffected at follow-up. Also the heart size in these patients decreased postoperatively. Survival seemed mainly related to the degree of preoperative cardiac failure and cardiomegaly.


Pacemaker twiddler's syndrome: a note on its mechanism.

Two elderly women were given a bipolar endocardial ventricular inhibited demand pacing system. They developed total loss of capture on the 16th and 62nd post-operative day and sikagrams of chest revealed pull out of endocardial catheter due to formation of multi-twined loop in the loose and laxed subcutaneous pulse generator pockets. Various mechanisms of this unusual complication with suggestions for prevention have been discussed.


Coronary perfusion under general and selective cardiac hypothermia.

Experiments to assess left ventricular function in dogs during and after 2 hours of hypothermic cardioplegia are reported. During the experiment myocardial temperature was maintained between 15 degrees C and 18 degrees C by controlling the rate of flow of a cool cardioplegic solution into the coronary vessels. Before and after the period of hypothermia the left atrial pressure was gradually changed and the aortic flows and pressures that changed in response were recorded. The left ventricular stroke work (gm) was then calculated using the relationship: LVSM = (formula: see text) where: SV = stroke volume (ml), AP = arterial pressure (mmHg), LAP = left atrial pressure (mmHg). Comparison of the calculated values indicated that this method of maintaining cardiac hypothermia reduced cardiac function only slightly.


Cimetidine, a histamine H2 receptor antagonist, occupies androgen receptors.

The histamine H2 receptor antagonist cimetidine is in increasing usage in the medical management of peptic ulcer. In clinical trials, its most frequent side effect is gynecomastia. Such estrogenic/antiandrogenic manifestations are well known side effects of treatment with digitoxin or spirolactones. Both of these drugs share a common skeleton with the steroid hormones and have been shown to occupy estrogen and/or androgen receptors. Cimetidine has no measurable affinity for rat uterine estradiol receptors, but competes for tritiated dihydrotestosterone-binding sites in mouse kidney preparations with a displacement curve parallel to that for unlabeled dihydrotestosterone. Steroid receptor-mediated side effects, therefore, may not be confined to molecules with a common skeleton, such as steroids, spirolactones, and cardiac glycosides, but may extend to such apparently unrelated molecules as histamine antagonists and androgens.


Solubilization of human thyroid microsomal antigen.

The ability of detergents (Triton X-100 and deoxycholate), high ionic strength solution (3 M KC1), and proteolytic enzymes (papain and trypsin) to solubilize human thyroid microsomal antigen was studied. Antigenic activity released from thyroid microsomal preparation into the incubation mixture was separated by centrifugation at 143,000 x g for 90 min and measured using 125I-labeled human immunoglobulin G (IgG) with elevated antimicrosomal (anti-M) and undetectable anti-thyroglobulin antibodies (anti-M IgG). All solubilized materials were shown to bind [125I]anti-M IgG and to inhibit its binding to untreated thyroid microsomes. These effects were specific and dose related. Measurements of specific activity and total amount of solubilized antigen by an absorption technique showed that Triton X-100 was the most effective agent, followed by deoxycholate, papain, trypsin, and 3 M KC1 in decreasing order. Affinity chromatography with the deoxycholate-solubilized material coupled to Sepharose 4B resulted in a 15.6-fold purification of [125I]anti-M antibodies. The present results indicate that thyroid microsomal antigen may be solubilized by several agents and this can provide the basis for its identification and purification.


Carcinoma of the breast associated with hypercalcemia and the presence of parathyroid hormone-like substances in the tumor.

A woman with metastatic carcinoma of the breast developed hypercalcemia 39 months after mastectomy. The hypercalcemia remitted after treatment but recurred 12 months later, accompanied by elevated levels of serum immunoreactive parathyroid hormone (PTH). A urea/HC1 extract of hepatic metastases contained immunoreactive PTH, material which stimulated the resorption of fetal rat bone in tissue culture, and material which stimulated chick renal adenylate cyclase activity. These findings strongly suggest that this breast cancer produced a PTH-like substance.


Enhanced adrenal responsiveness to angiotensin II in patients with low renin essential hypertension.

The plasma aldosterone response to infused angiotensin II was determined in normal controls and in patients with normal renin and with low renin essential hypertension. The patients with low renin essential hypertension showed an enhanced plasma aldosterone response when compared to the other two groups. This finding may explain why plasma aldosterone levels remain within normal limits in the face of suppressed plasma renin and angiotensin II concentrations in low renin essential hypertension.


Comparative potency of subtilisin-cleaved and intact human growth hormone measured in growth hormone-deficient human subjects.

Eight GH-deficient subjects received both subtilisin-cleaved human GH (hGH-S) and intact hGH (hGH-I) during short term balance studies to compare the potency of these two forms of GH. Both forms caused nitrogen retention, calciuria, postassium retention, and elevation of blood glucose. The effects on plasma insulin concentrations were inconstant at the doses used. hGH-S was more potent than hGH-I, as measured by nitrogen and potassium retention, and the differences reached levels of statistical significance. hGH-S also caused greater calciuria and increases in fasting the postprandial blood glucose and in postprandial insulin in absolute terms, but these differences did not reach levels of statistical significance. In no instance was hGH-I significantly more potent than hGH-S. We conclude hGH-S, a two-chain form of hGH, caused significantly greater nitrogen and potassium retention in human subjects in short term balance studies than hGH-I.


Metabolic clearance rate and interconversion of androgens and the influence of the free androgen fraction.

Using the continuous infusion technique, the conversion ratios (CR) of testosterone (T) to androstenedione (A) and dihydrotestosterone (DHT) and of A to T and DHT were determined in 12 normal males (aged 31-72 yr), 10 normal postmenopausal women, and 4 amenorrheic women with idiopathic hirsutism; in 4 additional males these studies were performed during infusion of cold T to increase plasma T to supraphysiological levels. It was observed that besides the MCR of T and DHT, the blood conversion ratios (CRBB) of T in A and to a lesser extent of T in DHT were also significantly correlated with either the free or the nontestosterone-estradiol-binding globulin-bound T fraction but not with total plasma T. In postmenopausal women, plasma A was by far the most important precursor of plasma DHT; the CRA/DHTBB was significantly higher than CRT/DHTBB. It is suggested that total plasma A, but only nonspecifically bound T, freely gains access into the cells where these conversions occur and that plasma A might be an important parameter of androgenicity. Less than 50% of plasma DHT could be accounted for by peripheral conversion of either A or T. Whereas in males this may be explained by direct DHT secretion, in (postmenopausal) women conversion of other precursors to plasma DHT should be considered.


Effect of three serotonin antagonists on plasma prolactin response to suckling in puerperal women.

The effect of the acute administration of three serotonin antagonists on plasma PRL levels and on the PRL response to suckling was investigated in a group of puerperal women. A single oral dose of metergoline or methysergide induced a significant decrease of plasma PRL levels and abolished the PRL response to suckling. Cyproheptadine administration did not modify either the plasma PRL levels or the PRL response to suckling. These results are discussed in light of the known pharmacological properties of the three antiserotonergic drugs.


Gynecomastia as a physical finding in normal men.

The prevalence of palpable gynecomastia was determined in 306 normal adult men ranging in age from 17-58 yr. Palpable breast tissue was present in 36% and was bilateral in all but 7 subjects. In the great majority of cases, the gynecomastia was 4 cm or less in diameter. A diameter greater than 5 cm was distinctly unusual. With advancing age there was a progressive increase in the prevalence of gynecomastia. This increase was most striking in those over the age of 44 and in the 20- to 24-yr-old group compared to those 19 yr old or less. In those over the age of 44, the prevalence was 57%. These data indicate that palpable gynecomastic is common in normal adult men. This high prevalence must be taken into consideration when attributing gynecomastia to a drug or disease state.


Persistent effect of sustained hyperglucagonemia on glucose production in man.

In man prolonged infusions of glucagon cause a transient increase in glucose production. To determine whether this represents complete loss of effect of hyperglucagonemia on the liver or merely decreased hepatic responsiveness, glucagon (3 ng/kg/min) was infused in six normal subjects to produce sustained hyperglucagonemia for 180 min; at this time glucagon infusions were stopped for 60 min, then restarted at the same rate for 60 min and finally increased to 7.5 ng/kg/min for 30 min. Glucose production (Ra) and utilization (Rd) were measured isotopically. Initially glucagon infusion increased Ra transiently from 1.8 +/- 0.1 mg/kg/min to a maximum at 15 min of 2.5 +/- 0.2 mg/kg/min (p less than .01); Ra returned to basal values by 60 min and remained there until the glucagon infusion was stopped, whereupon it abruptly declined to a nadir of 1.4 +/- 0.1 mg/kg/min, a value significantly below baseline levels, p less than .005. Upon restarting the glucagon infusion, Ra increased to a similar extent as observed with the initial infusion and then returned to basal levels; when the glucagon infusion rate was increased to 7.5 ng/kg/min, Ra again increased. These results indicate that sustained hyperglucagonemia, despite apparent waning of its effect, continues to modulate hepatic glucose production.


Dried Staphylococcus aureus as a rapid immunological separating agent in radioimmunoassays.

A rapid (less than or equal to 60 seconds) immunological separation of antigen-antibody complexes from free antigen has been developed in radioimmunoassays (RIAs) of luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL) and beta-endorphin by using suspensions of dried Staphylococcus aureus rich in protein-A. In the systems tested parallel dose-response curves were obtained for protein-A and second antibody precipitations. The sensitivity of the protein-A method is equal to or higher than that of second antibody method. Tissue culture medium and serum hormone levels measured with RIAs using protein-A are similar to those detected with double antibody methods. The technique may be of general use in all RIAs utilizing antisera from species whose IgG are known to be bound by protein-A.


Atypical clinical course of ornithine transcarbamylase deficiency due to a new mutant (comparison with Reye's disease).

A male infant with ornithine transcarbamylase (OTC) deficiency is described who was relatively symptom free for 4 months, gradually developed severe spasticity due to cerebral atrophy, and died at 13 months of age. Liver OTC activity was 1.5% of the normal mean. The mutant OTC showed an increased apparent Km for ornithine and an increased pH optimum. These kinetic findings fail to explain the atypical clinical course. The clinical picture of patients with genetic OTC deficiency who present during acute exacerbations together with the elevation of serum glutamic oxaloacetic transaminase and microvesicular fat accumulation in liver, as seen in this case, may suggest Reye's syndrome; however, electronmicroscopic examination of this patient suggested that the normal appearance of mitochondria helps to distinguish the two.


Relationship of free and total calcium in hypercalcemic conditions.

An assessment of free and total calcium measurements was made in 691 patients with suspected hypercalcemia or disorders often associated with hypercalcemia. In 18.9% of the 1049 specimens analyzed from nine different patient groups, a different impression of hypercalcemia was obtained depending on whether the free or total calcium was considered. Analysis of the ratio of free to total calcium indicated that there are two main factors which influence the distribution of calcium in the serum of hypercalcemic patients: the concentrations of albumin and parathyroid hormone. A lowered albumin concentration accounted for the altered distribution of calcium in patients with malignancies and partially accounted for the altered distribution in patients postrenal transplantation. In patients with confirmed primary hyperparathyroidism a higher ratio of free to total calcium was found, which could not be explained by alterations in protein, albumin, pH, or CO2 content but was related to parathyroid hormone concentration. Free calcium appears to be a slightly better indicator of elevated calcium states than total calcium. Measurements of free calcium should be particularly useful in patients with altered albumin concentration, with multiple myeloma in whom a calcium-binding protein could be present, after renal transplantation, and with suspected hyperparathyroidism and normal or slightly elevated total calcium values.


Immunoglobulin G-insulin antibodies and immune region-associated alloantigens in insulin-dependent diabetes mellitus.

The present study was undertaken to determine the importance of immune region-associated alloantigens for susceptibility to insulin-dependent diabetes (IDD), their possible influence on immunoglobulin G-insulin antibody formation, and their clinical significance. Incidence of DRw3 and DRw4 (HLA D-related immune region-associated alloantigens; w, defined by sera dispensed during the Seventh International Histocompatibility Workshop) was found with significantly increased frequency in the IDD patients (n = 50) compared to healthy individuals (n = 107). Subjects positive for DRw3 carry a 4.5-fold increased risk and those positive for DRw4 carry a 2.5-fold increased risk of developing IDD. By analyzing immunoglobulin G-insulin antibody titers in DRw3-positive and DRw3-negative patients (all treated with conventional Lente insulin), a significant tendency for high insulin-binding capacity (IBC) was noted in the latter group, yielding a mean IBC of 2.24 in DRw3-negative and 0.74 in DRw3-positive diabetics (P less than 0.02). A significantly increased insulin dosage was needed for adequate metabolic control in those patients with high IBC (IBC greater than 3.0 U/liter). Patients with high IBC and high insulin requirements were predominantly found to be DRw3 negative. Our data demonstrate that IDD is more closely associated with DRw3 than with all hitherto described HLA A, B, and C locus alloantigens of the major histocompatibility complex. In addition, these immunogenetic factors seem to be of clinical importance by influencing the humoral antiinsulin immune response.


The cyclic relationship of estrogen sulfurylation to the nuclear receptor level in human endometrial curettings.

Human endometrial curettings were selected principally from patients undergoing tubal ligations for elective sterilization. Specimens were analyzed for the metabolism of 17beta-[6,7-3H]estradiol and Na2 35SO4; assayed for the nuclear receptor content with 17beta-[6,7-3H]estradiol; and examined for the cytosol receptor content with 17beta-[2,4,6,7-3H]estradiol. The results of these experiments demonstrated that a) estrogen sulfotransferase activity is greatly stimulated during the secretory phase; b) although estrogen dehydrogenase is active throughout the menstrual cycle, the formation of estrone is elevated in concert with sulfurylation; and c) this increased metabolism of 17beta-estradiol is accompanied by a decreased nuclear uptake of the estrogen receptor complex. The importance of this endometrial estrogen metabolism in the maintenance of a secretory tissue is discussed.


Radioiodine in the treatment of medullary carcinoma of the thyroid.

Medullary carcinoma (MC) of the thyroid, in contrast to papillary-follicular carcinoma, fails to concentrate iodine and thus has not been treated with radioactive iodine. We have successfully treated a 16-yr-old Mexican-American girl with residual MC after maximal thyroidectomy (Tx), utilizing radioiodine (131I) to deliver radiation to residual follicular cells in the tumor bed. Immediately after Tx, plasma thyrocalcitonin levels before and during calcium infusion were all elevated (640--1200 pg/ml). 131I (150 mCi) was administered 12 days after Tx after four daily im injections of bovine TSH. Three months after 131I therapy, thyrocalcitonin levels before and during calcium infusion were all normal (less than 50 pg/ml). Ten months after 131I therapy, thyrocalcitonin levels before and after iv pentagastrin were all normal (less than 60 pg/ml). These results suggest that parafollicular cells are radiosensitive, and that therapeutic levels of radiation can be delivered to these cells after Tx if iodine trapping by the remaining follicular cells is enhanced by high levels of circulating TSH. 131I may be the therapy of choice for MC after Tx, if disease has not spread beyond the area proximate to the thyroid gland.


Augmentation of puerperal lactation by oral administration of sulpiride.

The effect of oral administration of sulpiride on PRL secretion and initiation of puerperal lactation was studied in 130 randomly selected primiparous nursing mothers. Sixty-six women were given 50 mg sulpiride orally twice a day during the first 7 days of the puerperium (sulpiride group). Sixty-four women were given a placebo in the same way (control group). The mean (+/-SE) total milk yield during the first 5 postpartum days in the sulpiride group (1211.7 +/- 65.0 ml) was significantly greater than that in the control group (916.0 +/- 66.0 ml). Every other day determinations of serum PRL levels revealed significantly higher concentrations in the sulpiride group than in the control group. A single oral dose of 50 mg sulpiride raised serum PRL levels for 12 h, with a peak level at 2 h after dosing in 7 women on the second postpartum day. These data suggest that sulpiride given orally promotes the initiation of lactation in puerperal women by stimulating PRL secretion.


Diminished gastric inhibitory polypeptide response to oral glucose in late human pregnancy.

It has been shown that the incretin effect - i.e. the gastrointestinal potentiation of the insulin response to oral glucose - is reduced in late normal pregnancy. As evidence points to gastric inhibitory polypeptide (GIP) as mediator of at least part of the incretin effect, the GIP response was determined following a 50 g oral glucose load in 6 normal women in the last trimester of pregnancy and again post partum. Compared to post partum the GIP response to oral glucose was significantly impaired in late pregnancy. It is concluded that the diminished GIP response to oral glucose in late pregnancy might at least partly explain the impaired incretin effect found in this condition.


Reversible defect of neutrophil chemotaxis and random migration in primary hyperparathyroidism.

Chemotactic and random migrations of neutrophils derived from four patients with primary hyperparathyroidism were found to be defective. These abnormalities improved significantly in parallel with the decrease in serum calcium and parathormone and with the increase in serum phosphorus concentration after surgical removal of the adenoma. These observation suggest a possible role for parathormone phosphorus and calcium in the motility of neutrophils.


C-Peptide and insulin secretion in Pima Indians and Caucasians: constant fractional hepatic extraction over a wide range of insulin concentrations and in obesity.

Peripheral serum insulin and C-peptide concentrations during oral glucose tolerance tests were measured in 10 nondiabetic Pima Indians and 10 nondiabetic Caucasians with varying degrees of obesity. Although both insulin and C-peptide levels were elevated in the Indians compared to the Caucasians (p less than 0.05), hepatic insulin extraction, measured by comparing the C-peptide to insulin ratios, was similar over a wide range of insulin concentrations in both groups. The ratios of C-peptide to insulin were independent of the degree of obesity. These studies indicate that the peripheral hyperinsulinemia in Pima Indians and obese subjects is due in general to pancreatic hypersecretion rather than to diminished hepatic extraction of insulin.


Stimulation of aldosterone, renin, and cortisol by tryptophan.

Tryptophan administration was used to evaluate the possibility that serotonergic neurons are involved in regulating the release of cortisol, renin, and aldosterone. Eleven studies were undertaken using 2 or 10 g tryptophan administered to fasting patients in continued supine posture. Aldosterone rose significantly to 208% (range, 128-329%) of baseline in all seven studies using 10 g and in one of the four studies using 2 g. Renin rose significantly to 189% (range, 116-340%) of baseline in four of the seven studies using 10 g and in two of the four studies using 2 g. Cortisol rose from 10.1 +/- 3.3 to 20.0 +/- 3.7 micrograms/100 ml (P less than 0.001 by t test) in six of the seven studies using 10 g and three of the four studies using 2 g. In eight studies, there was a significant rise of more than one substance after tryptophan administration. In six of these, peak values of the responding hormones occurred at the same time or within a single 30-min sampling interval despite the absence of a constant relationship between their rises. The results suggest participation of the central serotonergic nervous system in the control of renin and aldosterone in addition to its previously postulated role in cortisol release.


Increased estrogen production in obese men.

Serum estrone (E1) and 17beta-estradiol (E2) were noted to be 2-fold elevated in a group of morbidly obese men. Urinary E1 and E2 production rates were elevated in proportion to the degree of obesity, with values as high as 127 and 157 micrograms/day, respectively. Although serum testosterone (T) concentrations were reduced in obese men, averaging 348 +/- 35 vs. 519 +/- 42 ng/dl in lean controls, the dialyzable T fractions were elevated and, hence, the calculated free T concentrations were normal in obese men. Further, the obese men exhibited normal serum LH, FSH, and T responses to clomiphene citrate, indicating intact hypothalamic-pituitary-Leydig cell axes. MCRs of T and peripheral conversion of T to E2 and androstenedione (delta) to E1 were all increased in obese men in proportion to the percentage above ideal weight. Although the obese mean exhibited increased blood levels and production rates of estrogens, there were no signs of feminization, increased T-estrogen-binding, globulin levels, or suppressed basal gonadotropin levels, suggesting a lack of biological effect. We postulate that obese men exhibit defective estrogen receptors, leading to decreased T-estrogen-binding globulin, increased clearance of androgenic hormones, and elevated estrogen production rates.


Isolation and culture of human endometrial glands.

A simple method for isolation of glands from human endometrium has been developed. The procedure involves collagenase digestion of the endometrial tissue and filtration through sieves of various pore sizes. Isolated glands retained on the sieves were washed and collected in culture dishes. Tubular organization of the isolated glands was ascertained by examination of the preparations under inverted microscope and light microscopy of stained sections. The appearance of the glands was found to reflect different functional states of the endometrium and, possibly, to reveal abnormalities. Growth of monolayers of epithelial cells derived from the glands was observed within 24 h of culturing. Electron microscopy of the cells in 7-day monolayer preparations from both proliferative and secretory endometrium revealed the characteristic features of human endometrial epithelial cells, viz. presence of microvilli and desmosome-like junctions. Nuclear bodies were observed in cells derived from both types of endometrium.


Absent growth hormone response to L-tryptophan in acromegaly.

In acromegaly, regulation of GH secretion by dopamine pathways appears to be qualitatively abnormal. To determine whether regulation of GH secretion by serotonin pathways is also abnormal in acromegaly, we administered L-tryptophan (5 g orally), the initial precursor of serotonin, to 10 patients with active acromegaly (9 treated and 1 untreated), 3 patients with cured acromegaly, and 8 normal subjects. The normal group showed a significant (P less than 0.05) increase in serum GH after L-tryptophan [peak value, 12.3 +/- 4.0 (se) ng/ml], though the magnitude of the response was highly variable. In contrast, subjects with active acromegaly did not show an increase in serum GH after L-tryptophan [mean integrated percentage change in serum GH, -25 +/- 25% (SE); P = NS]. One patient whose acromegaly had been surgically cured did show a GH rise after L-tryptophan. In acromegaly, the GH response to L-tryptophan is absent, suggesting that regulation of GH secretion by serotonin pathways might be qualitatively abnormal.


Acid-ethanol-extractable nonsuppressible insulin-like activity (NSILA-S) during pregnancy and the puererium, and in cord serum at term.

A longitudinal study of serum NSILA-S during normal human pregnancy and the puerperium has demonstrated that levels rose progressively during pregnancy and returned to nonpregnant values about 48 h after delivery. Low concentrations were defined within the feto-placental circulation at term. Cord arterial and venous levels were equivalent, but there was no significant correlation between these and matched maternal values.


Specific cytosol receptors for 1,25-dihydroxyvitamin D3 in human intestine.

Human intestine is shown to contain a specific, high affinity cytosol receptor or binding protein for 1,25-(OH)2-vitamin D3 [1,25 (OH)2D3]. This receptor is a protein which sediments at 3.5S on sucrose gradients containing 0.3 M KCL. The receptor binds 1,25 (OH)2D3 with a Kd of approximately 2 x 10(-10) M at 4 degrees C. Competition binding studies using structural analogs of 1,25 (OH)2D3 indicate that the relative specificity of the receptor is 1,25 (OH)2D3 greater than 1,24R,25(OH)3D3 greater than greater than 25OHD3 1 OHD3 greater than 24R,25(OH)2D3.


Effects of a dopamine antagonist on the release of gonadotropin and prolactin in normal women and women with hyperprolactinemic anovulation.

Administration of a dopamine (DA) antagonist, metoclopramide (MCP) resulted in dose-related acute increments of circulating levels of LH and FSH in patients with hyperprolactinemic anovulation due to pituitary microadenoma but not in normal cycling women during the early follicular phase. Concomitant PRL responses to MCP in hyperprolactinemic patients were 1/10 those observed in the cycling women. These findings suggest a relative DA excess at the hypothalamic LRF neurons and a relative DA deficiency at the adenoma lactotroph of hyperprolactinemic patients as compared to cycling women.


Increased ratio between changes in blood pressure and plasma norepinephrine in essential hypertension.

The pathogenic role of the sympathetic system in essential hypertension was evaluated by combined analysis of plasma catecholamine levels and the pressor sensitivity to endogenous norepinephrine. The latter was estimated indirectly by the ratio between changes in blood pressure and those in plasma norepinephrine after adrenergic neuronal blockage with debrisoquine (given orally for 6 weeks). Normal subjects and patients with borderline or established essential hypertension had comparable pretreatment levels of plasma norepinephrine and epinephrine. Debrisoquine lowered plasma norepinephrine by a similar degree (almost 50%) in these three groups; in contrast, blood pressure decreased only slightly in normal or borderline hypertensive subjects [-3.4 +/- 3.2% and -5.4 +/- 1.6% (SE), respectively] but fell significantly more (P less than 0.005) in patients with established essential hypertension (-20.7 +/- 3.9%). The ratio between percentile changes in blood pressure and those in endogenous norepinephrine levels was comparable in normal and borderline hypertensive subjects (0.03 +/- 0.08 and 0.17 +/- 0.04, respectively), but increased (P less than 0.001) in established essential hypertension (0.62 +/- 0.11). This suggests that essential hypertension may be maintained, at least partly, by the inappropriate association of normal plasma norepinephrine levels with increased norepinephrine pressor sensitivity.


Comparison of estimates of gonadotropin levels by isolated blood samples, integrated blood concentrations, and timed urinary fractions.

Gonadotropin levels in isolated blood samples, integrated plasma concentrations (IC), and timed urinary collections have been compared in 5 males with delayed puberty and 7 normal adult males. There was a significant correlation between urinary levels in 24-h collection and those in each of four shorter timed collections for both LH and FSH. Similarly, 24-h integrated plasma concentration and 4-h (0800--1200 h) integrated plasma concentration obtained on 10 additional subjects showed significant correlation. The 4-h integrated plasma concentrations correlated with single blood samples or the mean of three samples obtained at 0800, 1200, and 1600 h. These 4-h plasma samples also correlated significantly with all urine collections for FSH but only with the 2200--0800 h urine collection for LH. The study suggests that LH and FSH levels in urine samples collected over several hours correlate with 24-h urinary excretion and that levels in single blood samples estimate the 24-h plasma integrated concentration.


Urinary follicle-stimulating hormone during pregnancy: relationship to sex of fetus.

FSH excretion was determined by RIA in 111 urine samples from 23 pregnant women. The use of acetone extraction allowed a 20-fold concentration of urine and the accurate quantitation of hormone levels. Between 10 weeks of gestation and term, FSH secretion was consistently low, with a mean excretion of 18 mIU/h; this amount compares to levels found in other states of marked hCG excess (e.g. choriocarcinoma) and is considerably less than the FSH excretion by prepubertal children. Maternal levels of urinary FSH did not differ with sex, suggesting a primary maternal pituitary origin for pregnancy FSH.