A calcium-binding protein in bile and gallstones

Calcium salts are often present in the center of all types of gallstones. Matrix proteins are known to be essential for biomineralization and may therefore also be important in the formation and growth of gallstones. Other researchers have described an anionic peptide fraction of a biliary lipoprotein complex in bile and a low-molecular weight acidic glycoprotein present in gallstones. Our goal was to determine whether such a protein was present in bile and whether this protein has any calcium-binding properties. We identified a pigment-associated, highly acidic protein that precipitates from bile on addition of CaCl2 0.5 mol/L. In addition, the protein is selectively concentrated in cholesterol and pigment stones. We have, therefore, confirmed the findings of these other researchers, and we have extended the study of this protein's interactions with calcium. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrates a single band (molecular weight < or = 14 kD) that reacts positively with cationic stains. The protein was shown to inhibit the precipitation of CaCO3 from a supersaturated solution. The capacity to bind calcium was further confirmed by autoradiography with 45Ca++ and by a membrane adsorption-binding assay. Calcium-induced aggregation was demonstrated by equilibrium dialysis and by quasielastic light scattering studies. Protein measured by Lowry's assay method and amino acid analysis constitutes only 2% to 4% of the harvested material. We speculate that a substantial lipid component may also be present.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation of Caenorhabditis elegans mutants lacking alcohol dehydrogenase activity

Alcohol dehydrogenase (ADH) and the genes encoding this enzyme have been studied intensively in a broad range of organisms. Little, however, has been reported on ADH in the free-living nematode Caenorhabditis elegans. Extracts of wild-type C. elegans contain ADH activity and display a single band of activity on a native polyacrylamide gel. Reaction rate for alcohol oxidation is more rapid with higher molecular weight alcohols as substrate than with ethanol. Primary alcohols are preferred to secondary alcohols. C. elegans is sensitive to allyl alcohol, a compound that has been used to select for ADH-null mutants of several organisms. Allyl alcohol-resistant mutant strains were selected from ethylmethanesulfonate (EMS)-mutagenized nematode populations. ADH activity was measured in extracts from eight of these strains and was found to be low or nondetectable. These results form a basis for molecular and genetic characterization of ADH expression in C. elegans.

Evaluation of the stability of neuropsychological functioning after acute episodes of schizophrenia: one-year followup study

Few studies have evaluated the longitudinal stability of neuropsychological deficits in schizophrenia. In the present study, 39 inpatients with DSM-III-R schizophrenia were administered a comprehensive battery of neuropsychological tests after achieving sufficient clinical recovery to warrant discharge, and again 1 year after the first assessment during a nonacute period. Significant improvement in neuropsychological functioning from the first to the second assessment was observed on several tasks, including the following: Trails A and B, Digit Symbol, Judgment of Line Orientation, recognition memory on the Rey Auditory Verbal Learning Test, the Wisconsin Card Sort, and Finger Tapping. These improvements were unrelated to treatment history, and were similar in first episode and chronic cases. For many patients, the improvement in functioning brought test performance into line with normative scores from test standardization samples. These results indicate that considerable improvement in neuropsychological functioning can occur in schizophrenic patients over the months following an acute episode of illness, and that recovery of cognitive functioning can occur after substantial clinical recovery from an acute episode of illness has already been achieved.

Diode-pumped Cr:LiSrAlF(6) laser

A Cr:LiSrAlF(6) laser is diode pumped with both commercial 10-mW visible laser diodes and a higher-power 100-mW cw, 265-mW pulsed diode. Polarization combination of pump diodes to reach threshold is demonstrated with two low-power lasers. Pumping with the high-power diode produced powers of 19.9 mW cw and 78 mW pulsed. Details of the Cr:LiSrAlF(6) crystal growth and high-power diode architecture are presented, along with optical characterization data for the laser resonator. Passive losses in the crystal are less than 0.1% cm(-1).

Single-dose trospectomycin for chlamydial urethritis in men

Trospectomycin is an aminocyclitol analog of spectinomycin with significant in vitro activity against Chlamydia trachomatis. A single 1-g intramuscular dose was administered to 10 men with symptomatic, culture-positive chlamydial urethritis. Trospectomycin was well tolerated but failed to eradicate chlamydial infection, as determined by cultures obtained approximately 1 week after treatment.

Codon usage divergence of homologous vertebrate genes and codon usage clock

This paper is concerned with the divergence of synonymous codon usage and its bias in three homologous genes within vertebrate species. Genetic distances among species are described in terms of synonymous codon usage divergence and the correlation is found between the genetic distances and taxonomic distances among species under study. A codon usage clock is reported in alpha-globin and beta-globin. A method is developed to define the synonymous codon preference bias and it is observed that the bias changes considerably among species.

Effect of electric field on erythrocyte sedimentation rate. II. Dependence on electric current

We measured the electric current dependence of sedimentation curves of swine erythrocytes in a saline solution at the volume fraction of erythrocytes H = 0.091 and 0.220. The sedimentation curve fitted well to the exponential type equation l = a[1-exp(-bt)] at the upward initial electric current I0 = 0.50 mA, 1.01 mA and 1.50 mA, where l is the length of the medium layer at time t, and a and b are phenomenological parameters. The initial slope v0 of sedimentation curve was enhanced from 0.68 mm/hr at I0 = 0 mA to 2.85 mm/hr, 3.87 mm/hr and 5.50 mm/hr at I0 = 0.50 mA, 1.01 mA and 1.50 mA, respectively, for H = 0.220. We also made sedimentation measurements of erythrocytes in their own plasma at H = 0.220 and 0.316. Sedimentation curves coincided with the sigmoidal type equation l = l infinity/[1 + (t50/t)beta] at I0 = 0 mA and 0.50 mA, where l infinity is l at t----infinity, t50 is the time when the plasma level falls to l infinity/2 and beta is a constant. The maximum slope vmax of sedimentation curve increased from 13.29 mm/hr at I0 = 0 mA to 18.65 mm/hr at I0 = 0.50 mA for H = 0.220.

The impact of a resident dog on an institution for the elderly: effects on perceptions and social interactions

A longitudinal case study was made of a sub-unit of a nursing home to examine the perceptions and social interactions of patients and staff after introduction of a resident dog. A behavioral mapping procedure was used to determine staff and patient interactions 6 weeks before and 6 weeks and 22 weeks after the dog's arrival. Interviews were also conducted with patients and staff. Six weeks after the dog's arrival, a significant increase in frequency of interactive behaviors was seen for both staff and patients. By 22 weeks, behaviors for patients had reverted to base-line levels, while remaining high for staff.

Source of methyl groups in brain and nerve tissue in the rat

Previous studies that demonstrated that mouse brain accumulated significantly more radioactivity from subcutaneously administered 5-methyltetrahydrofolate labelled in the methyl group compared to the label in the folate moiety are open to two interpretations. The methyl group could have been transferred to another compound (probably methionine) prior to its transport into the brain. Alternatively, if plasma 5-methyltetrahydrofolate per se is significantly involved in the provision of methyl groups to brain and nerve tissue it would be expected that the folate moiety would be returned to the plasma to complete the cycle and thus would appear not to have been taken up. In this article, using competition experiments that exploit the differences in the mechanism of transport of methionine and 5-methyltetrahydrofolate into brain and nerve, evidence is presented that in the rat the methyl group of 5-methyltetrahydrofolate is transported after its conversion to methionine.

Interpretation of pulmonary artery wedge pressure and pullback blood gas determinations during positive end-expiratory pressure ventilation and after exclusion of the bronchial circulation in the dog

Left atrial pressure (LAP) and pulmonary artery wedge pressure (PWP) were measured at different heights during graded increases in positive end-expiratory pressure (PEEP). Six healthy anesthetized dogs were placed in lateral decubitus positions with a balloon-tipped pulmonary artery catheter inserted in each lung. PWP in the gravitationally superior lung overestimated LAP at 15 and at 20 cm H2O PEEP (p less than 0.05). PWP in the dependent lung was virtually identical to LAP at all degrees of PEEP. Wedge blood could be aspirated through the distal lumen of the pulmonary artery catheters during balloon inflation at all degrees of PEEP except for 3 attempts. PCO2 in wedge blood in both the nondependent and dependent lungs at all degrees of PEEP was consistently lower than PCO2 in arterial blood (p less than 0.05). Wedge blood was arterialized, i.e., oxygen saturation greater than 95%, in all but 4 specimens. Surgical elimination of the bronchial artery supply to the lung in 3 dogs did not affect PWP or blood gas measurements. We conclude that in this animal model: (1) the tip of a pulmonary artery catheter must be below the level of the left atrium, Zone III location, to accurately reflect LAP at high degrees of PEEP; (2) arterialization of wedge blood samples does not guarantee that PWP reflects LAP; (3) bronchial artery blood supply does not affect PWP or wedge blood gas measurements, even at high degrees of PEEP.

Extracellular matrix promotes the growth and differentiation of murine hematopoietic cells in vitro

We have developed a long-term culture system in which murine marrow cells are cultured on a complex extracellular matrix (ECM) that is derived from marrow and extracted with guanidine hydrochloride and dithiothreitol. Marrow cultures were established with fresh murine marrow cells and recharged at 2 wk (week 0). Phase microscopy showed a dramatically increased adherent cell layer development on ECM compared with controls within a week after recharge. By electron microscopy, this adherent layer was composed of numerous reticular cells apparently attached to the ECM which extended cytoplasmic projections to the surrounding hematopoietic cells. Adherent cellularity on ECM-coated dishes increased to 30 times the control values by week 2. Cumulative suspension cells on ECM dishes were eight times controls. ECM influenced both hematopoietic progenitor cell proliferation and differentiation. Adherent colony-forming unit-granulocyte/macrophage and colony-forming unit-megakaryocyte were greater than 30 and 15 times the control values, respectively, by week 2 (P less than or equal to 0.05). There were more mature granulocytic and megakaryocytic cells in ECM-coated dishes than in controls at all time points. This new culture system directly demonstrates that ECM is an important component of the hematopoietic microenvironment.

Lorazepam: a randomized, double-blind, crossover study of a new antiemetic in patients receiving cytotoxic chemotherapy and prochlorperazine

Lorazepam was compared to placebo to assess its control of nausea and vomiting in patients receiving cytotoxic chemotherapy and prochlorperazine. The study design was a randomized, double-blind crossover in which three consecutive chemotherapy courses were compared so that each patient acted as his or her own control. Of 107 patients entered, 80 were evaluable for analysis. Lorazepam significantly reduced the severity and duration of nausea, the severity of vomiting, and the number of vomiting episodes when compared to placebo. Anxiety was reduced during lorazepam courses but not significantly when compared to placebo. There was significantly more sedation with lorazepam courses. Overall, patients preferred lorazepam courses although this preference was significant only in the patient subset receiving doxorubicin and cyclophosphamide. Lorazepam is a useful adjunct to prochlorperazine in patients receiving cytotoxic chemotherapy.

Naltrexone: a short-term treatment for opiate dependence

The narcotic antagonist, naltrexone, was studied in 242 patients during a 6-year period. Although a large number of subjects discontinued naltrexone abruptly, treatment was related to a significant decrease in opiate and nonopiate drug use. Methods for improving retention during induction and maintenance are discussed and posttreatment outcome results are presented. The authors conclude that naltrexone may be a useful short-term treatment option for opiate dependence.

Psychiatric diagnosis of morbidly obese gastric bypass patients

Eighty morbidly obese patients who had had gastric bypass operations were interviewed for psychiatric diagnoses using DSM-III criteria. The lifetime prevalence of Axis I clinical psychiatric diagnoses was 47.5%, with depressive disorders occurring in 28.7% of the total sample. No other diagnosis exceeded a 2.5% prevalence. The authors believe there is no evidence of an increased prevalence of major psychiatric disorder in obese persons when strictly defined diagnostic criteria are used.

The technique and early results of high gastric reduction for obesity

The high gastric reduction operation has been performed on one hundred and nine obese patients over a sixteen-month period. Patient selection, preoperative care, operative technique and postoperative care are described. Our early results show that a satisfactory initial and continuing weight loss can be sustained for a twelve-month period with a low morbidity and mortality. Further follow-up of these patients is required before the ultimate place of this procedure is established.

Effects of contingent payment on compliance with a naltrexone regimen

The effects of several schedules of payment on duration and patterns of compliance with a naltrexone regimen were examined. Patients were paid under contingencies based on either number of doses ingested or on a fixed time schedule. Reinforcement schedules based on number of doses ingested produced more consistent treatment-oriented behavior than a time-based schedule. Covariation between behavior and alternating contingencies (A-B-A) indicated that the schedules contributed to increased duration of treatment compared to previous noncontingent payment. The issue of using extrinsic reinforcers such as monetary payment to enhance compliance is discussed and additional procedures are suggested.

Blood pressure recording in children

Blood pressure levels for 148 children aged 0-14 years were recorded. Two different methods of measurement (the standard sphygmomanometer and the random-zero machine) and two cuffs of varying size were used on each child. Measurements of arm size and pulse rate were taken, and an assessment was made of the emotional state of each child: no association was found between these factors and the recorded measurement of blood pressure. The experiment does however show that: (1) the effect of cuff size can be minimized by using the largest cuff that will fit the child, and then applying a standard correction to the measurement taken; and (2) the random-zero machine is a preferable method of measurement as it reduces observer bias, though measurements taken with a standard and a random-zero machine are not directly comparable.