The major neutral proteinase of Entamoeba histolytica

FPLC anion-exchange and chromatofocusing chromatography were used to purify the major neutral proteinase from secretions of axenically cultured Entamoeba histolytica trophozoites. HM-1 strain trophozoites, which were more proteolytically active than the less virulent HK-9 strain, were used for purification of the enzyme. It is a thiol proteinase with a subunit Mr of approximately 56,000, a neutral pH optimum, and a pI of 6. The importance of this enzyme in extraintestinal amoebiasis is suggested by its ability to degrade a model of connective tissue extracellular matrix as well as purified fibronectin, laminin, and type I collagen. The enzyme caused a loss of adhesion of mammalian cells in culture, probably because of its ability to degrade anchoring proteins. Experiments with a peptide substrate and inhibitors indicated that the proteinase preferentially binds peptides with arginine at P-1. It is also a plasminogen activator, and could thus potentiate host proteinase systems.

Clinical comparison of a new automated infrared blood culture system with the BACTEC 460 system

A new blood culture instrument, the BACTEC (Johnston Laboratories, Inc., Towson, Md.) NR-660, which utilizes infrared detection of carbon dioxide from microbial metabolism, was compared with the radiometric BACTEC 460 system. There were 1,554 isolates from 18,785 paired aerobic blood cultures. Of these isolates, 1,303 were isolated from the radiometric 6B medium, and 1,259 were isolated from the NR6A medium (P = 0.06). Analysis of the data indicated no significant differences in recovery when any individual species was considered. When organisms were considered as groups, there were no significant detection differences for gram-negative bacilli, yeasts, or anaerobes. For gram-positive cocci in aerobic medium, the BACTEC 460 detected 84.3% of the total isolates, and the BACTEC NR-660 detected 79.7% (P = 0.04). There were 891 isolates from 13,983 paired anaerobic blood cultures. Of these isolates, 725 were recovered from the radiometric 7D BACTEC medium, and 723 were recovered from the NR7A BACTEC medium (P greater than 0.9). In the anaerobic media there was no significant difference in detection of any organism group, including the gram-positive cocci. When the results of the aerobic and anaerobic media were combined, there was equivalence between the two systems for the detection of gram-positive cocci (P greater than 0.2) and other organism groups. When the ability to detect septic episodes was compared, there was no significant difference for any organism group (P = 0.12). For aerobic media, the mean times for detection were 30.5 and 29.5 h for the BACTEC 460 and NR-660, respectively. For anaerobic media, the mean times for detection were 39.8 and 41.6 h for the BACTEC 460 NR-660, respectively. Compared with the BACTEC 460, the BACTEC NR-660 system had a greater ease of operation, faster test cycle, computerized data base, and equally rapid detection of positive cultures.

Pharmacokinetics of lopamidol after intrathecal administration in humans

The kinetics of iopamidol, a new nonionic radiocontrast agent, were evaluated in 10 patients undergoing lumbar myelography. The doses of iopamidol administered intrathecally were 11 and 15 ml of a 200-mg iodine per ml solution in one and nine patients, respectively. Radiographs were made within 30 to 40 min and CTs were taken at about 1, 6, and 23 hr after iopamidol administration. The diagnostic quality and usefulness of the conventional and CT myelograms were considered excellent. In the lumbosacral subarachnoid space, the densitometry CT readings were maximal at 1 hr, whereas in the cervical subarachnoid space, peak CT values were reached at 6 hr. Plasma and urine samples were taken at frequent intervals up to 48 hr after the contrast agent was administered. Peak plasma levels of iopamidol were observed at 2.9 hr and were no longer detectable at 48 hr. The 48-hr urinary recovery for all patients averaged 66 +/- 8% of the dose. In all but one patient, iopamidol was cleared almost completely from the CSF within 24 hr. Side effects after iopamidol administration were transient and minor, and were not related to the CT readings or its systemic clearance.

Influence of the 30 degrees laterally inclined position and the 'super-soft' 3-piece mattress on skin oxygen tension on areas of maximum pressure--implications for pressure sore prevention

The measurement of the transcutaneous PO2 (tc PO2) demonstrates that localized pressure on skin sites under bony prominences (e.g., the sacral and trochanteric areas) decreases the tc PO2 at these skin positions to zero when subjects are lying motionless on a normal hospital mattress. This explains the high risk of pressure sore formation in elderly patients, who have a greatly reduced frequency of involuntary movements. Therefore, the first principle of pressure sore prevention is the elimination of localized pressure on both the trochanteric and sacral skin areas simultaneously. This can be achieved by bedding elderly patients who are at risk on a 'super-soft' mattress and by turning them regularly to the 30 degrees laterally inclined position. With healthy adults, placed in this position, both the skin areas over the trochanteric and sacral bony prominences remain almost free from pressure and thus normally oxygenated. In addition, the tc PO2 measurement allows an immediate assessment of the efficacy of a procedure for sore prevention.

Pharmacokinetics of low-dose 1-beta-D-arabinofuranosylcytosine given by continuous intravenous infusion over twenty-one days

The pharmacokinetic parameters of low dose 1-beta-D-arabinofuranosylcytosine (ara-C) infusions were studied in 11 patients, 6 males and 5 females, with a mean age of 68.5 +/- 13.8 (SD) years. The drug was infused to 4 patients with pre-leukemia (refractory anemia with excess blasts), 5 patients with acute myelogenous leukemia, and 2 patients with secondary leukemia due to chemotherapy, at a dosage of 20 mg/m2/day over 21 days. The patients' blood and urine were analyzed for ara-C content by radioimmunoassay. Mean steady state plasma levels of 7.7 +/- 4.7 ng/ml (31.7 +/- 19.3 nM) (n = 189) and a range 0.6 (2.5 nM) (lower limit of assay) to 29.7 ng/ml (122.1 nM), with significant inter- and intra-patient variations, were reached within about 2.7 h. The plasma levels of ara-C decreased rapidly, with a t1/2 alpha of about 12 min following discontinuation of the infusion, followed by a very slow t 1/2 beta of about 19 h. Other parameters (mean values of 10 or 11 patients) were: area under the curve, 182.1 +/- 64.8 ng X day/ml; total body clearance, 188.7 +/- 54.8 liters/h; renal clearance, 3.1 +/- 1.4 liters/h; volume of distribution at steady state, 53,913 +/- 17,626 liters; and recovery of ara-C in urine, 1.43 +/- 0.69% (n = 226) of daily administered ara-C. A linear relationship was observed with administered dose when the mean plasma levels of our study were compared with the ones reported for conventional ara-C infusions. Plasma clearance was comparable to that observed in conventional dose, when the observed values were extrapolated to the dose administered in this study.

Baseline hemodynamic state and response to hemodilution in patients with acute cerebral ischemia

Hemodynamic data were obtained in 9 patients (mean age 65 yrs) with carotid territory cerebral infarct within the preceding 24 hours (mean 14 +/- 8) as part of a pilot study testing the feasibility and safety of hypervolemic hemodilution. Pulmonary arterial catheters (PACs) were placed without complication in all patients, and after baseline measurements were obtained, up to 1500 cc of 6% hetastarch in 0.9% sodium chloride was administered the first day and up to 1000 cc per day the second and third days. Pulmonary wedge pressure (PWP) rose from 6.3 +/- 3.5 to 14.4 +/- 3.4 mm Hg (p less than 0.001) without development of congestive heart failure in any patient. This was accompanied by a drop in hematocrit (Hct) from 40.3 +/- 3.4 to 32.9 +/- 2.0 (p less than 0.001) and rise in cardiac output (CO) from 4.3 +/- 1.0 to 5.3 +/- 0.6 (p less than 0.05). Phlebotomy of 250 cc was performed in 2 patients and 500 cc in one in order to reduce Hct to desired levels. The volume of fluid needed to raise PWP to 15 was unpredictable (2361 +/- 1106 cc) and therefore PACs were necessary to monitor the rate and volume of fluid administration. The data show that PWP is sufficiently low and Hct sufficiently high following stroke in most patients that hemodilution by volume expansion with phlebotomy added if necessary can be undertaken safely with appropriate monitoring of hemodynamic function, and that this therapy results in optimal reduction of Hct and increased CO without risk of hypotension.

A comparison of Hexabrix and Renografin-60 in knee arthrography

Forty patients were randomized in a double-blind study to compare the safety and diagnostic quality of Hexabrix vs. Renografin-60 without epinephrine in knee arthrography. Hexabrix is a monoacidic dimer of meglumine and sodium salts of ioxaglic acid with a lower osmolality than conventional contrast agents of similar concentration (32% iodine). Initial films were of equally high diagnostic quality for both groups, but delayed films at 20 and 30 min significantly favored Hexabrix for diagnostic quality. Hexabrix proved to be a safe and effective contrast agent for knee arthrography.

Rapid enzymatic characterization of clinically encountered anaerobic bacteria with the API ZYM system

The purpose of this study was to determine if enzyme profiles of anaerobic bacteria, obtained with the API ZYM system, are sufficiently distinctive and reproducible to merit future development of the system and an expanded data base for the four major groups of clinically encountered anaerobes. Of the total 155 clinical isolates and reference strains that were tested, 88% had distinctive patterns. It was possible to differentiate between 89% of the anaerobic gram-negative bacilli, 64% of anaerobic cocci, 100% of anaerobic gram-positive non-sporeforming bacilli and 100% of the Clostridium spp. using only the API ZYM plus Gram reaction, morphology and relation to oxygen. Overall reproducibility for 1,330 enzyme-substrate reactions was 97%. It was concluded that the API ZYM could be a practical system for rapid identification of clinical anaerobe isolates provided that an expanded data base is developed and that certain additional recommended tests are used.

A rapid and safe method of estimating nanomole quantities of P, K+, Na+, Ca2+, and Mg2+ in plant material by perchloric acid digestion

A method for the determination of nanomole amounts of P and major cations in samples of dried plant tissue is described. Samples weighing 2-7 mg were digested by refluxing tissue in a mixture of perchloric and nitric acids, under conditions which minimized the hazards associated with perchloric acid digestion. In most tissues analyzed, reproducibility between triplicate samples was less than +/- 5%. However, where the amount of P in the tissue was very low (samples contained about 50 nmol P each), the variation between triplicates was greater.

Safety of contrast media in cerebral angiography: iopamidol vs. methylglucamine iothalamate

A randomized double-blind study was performed in 27 patients to compare the clinical safety, incidence of pain and warmth, and film quality produced by iopamidol and Conray-60 in selective cerebral angiography. No complications or adverse reactions occurred in either group. Iopamidol was significantly less painful than was methylglucamine iothalamate for common carotid artery injections and caused significantly less heat in both common carotid and internal carotid artery injections. Film quality and diagnostic accuracy were excellent in both groups. These results, when viewed in conjunction with laboratory data demonstrating the decreased neurotoxicity of nonionic contrast agents, suggest that iopamidol is an important advance in the development of angiographic contrast media.

Decubitus ulcer prevention: a new investigative method using transcutaneous oxygen tension measurement

Sacral skin oxygen tension, measured by a noninvasive technique in ten healthy subjects, remained in the normal range when they were lying on a "super-soft" mattress or in the 30 degrees lateral position. Therefore, these methods are effective in decubitus ulcer prevention. Skin oxygen tension measurement allows immediate assessment of the efficacy of measures to prevent decubitus ulcers.

A factor analytic study of screening scales of adjudicated delinquent males and females

Obtained a factor analysis of demographic and behavioral variables from self-ratings and observations of trained raters on a sample of 200 incarcerated delinquents, which resulted in eight identifiable factors with eigenvalues over 1.0. These were described as: The undersized youthful offender with emotional problems, the aggressive threatening offender, the drug subculture repeat offender, the neurotic polyabuse offender, the institutionally unadjusted offender, the bright offender, the immature neurotic offender, and the "established" psychopathic offender. Results provide understanding of the relationships and disparities between self-ratings, the ratings of others, and demographic variables.

A double-blind comparison of bupropion and amitriptyline in depressed inpatients

Bupropion and amitriptyline were compared in a double-blind study of depressed inpatients. Treatment ranged from 2 to 4 weeks: early responders (Hamilton Depression Scale scores less than 10) were often removed from treatment after 2 or 3 weeks. Twenty-two patients completed treatment with bupropion and 18 with amitriptyline. Doses ranged from 450 to 750 mg/day for bupropion and 75 to 225 mg/day for amitriptyline. Overall, bupropion and amitriptyline were equally effective, as measured by the Hamilton Depression and Anxiety scales, Clinical Global Impressions, Zung Depression scale, and the SCL-90. Differences in the side effect profile and in weight change are described.

A double-blind clinical trial of iopamidol versus metrizamide for lumbosacral myelography

A double-blind study was performed to compare metrizamide with the new iodinated water-soluble nonionic contrast medium, iopamidol, for conventional and computerized tomography lumbosacral myelography. Both contrast agents were used in 30 patients, and were equivalent in terms of image quality and clinical accuracy. Headaches and nausea were less severe using iopamidol. The most striking difference was found in adverse neurobehavioral reactions and associated electroencephalographic abnormalities, which were noted in 17% of the metrizamide group but were not seen with the use of iopamidol. Iopamidol appears to be superior to metrizamide for intrathecal applications. An explanation of the differential neurotoxicity is provided.

Iopamidol vs metrizamide: a double blind study for cervical myelography

A double-blind study was performed on 20 patients comparing the safety and efficacy of Iopamidol and Metrizamide in cervical myelography. The radiographic qualities of the Iopamidol and Metrizamide examinations were equivalent when using the same volume (12 to 13 ml), concentration (200 mg I/ml), and a C1-2 route of administration. The performance of a CT scan on selected patients in specified areas of interest provided additional diagnostic information in some patients (e.g syringomyelia, degenerative spondylosis). The adverse reactions were mild in the Iopamidol group with 4 of the 10 patients experiencing no adverse reactions. The more severe reactions, including disorientation, agitation, dysarthria, asterixis, hyperreflexia and EEG abnormalities were limited to the Metrizamide group with one or more occurring in 2 of the 10 patients studied. Only one Metrizamide patient experienced no adverse reactions. In this study containing a limited number of patients, Iopamidol was shown to be a diagnostically effective and safer contrast medium for performing cervical myelography.

Inhibition of two mitochondrial enzymes by gold (III) halo complexes. Evidence for a binding mechanism

Fumarase (EC 4.2.1.2) and mitochondrial L-malate dehydrogenase (EC 1.1.1.37) were both inhibited by NaAuCl4 and KAuBr4. The inhibition for both was measured as a function of gold complex concentration and aquation time, and the NaAuCl4 inhibition was also measured in the presence of 0.15 M NaCl. Regeneration of the enzyme activity after NaAuCl4 inhibition using L-cysteine, L-methionine and NaCN was also investigated. Sodium dodecyl sulfate (SDS) acrylamide gel electrophoresis and amino acid analysis was performed on the NaAuCl4 inhibited enzymes as well as on ribonuclease A (EC 3.1.26.2), lysozyme (EC 3.2.1.17) and liver alcohol dehydrogenase (EC 1.1.1.1). It was observed that the inhibition was proportional to the gold complex concentration but decreased markedly after aquation of the complex. In the presence of NaCl the initial rate of inactivation is essentially unaffected unless the complex has been aquated and then the initial rate is increased. Gel electrophoresis on gold complex-enzyme mixtures show polymerization for ribonuclease and lysozyme and amino acid analysis indicates that no oxidation has taken place. From these results, a binding mechanism is postulated for the inhibition of the dehydrogenases by direct displacement of a halide ligand, probably by two groups on the enzyme, at least one of which may be a sulfur containing acid.

Study of safety and tolerance of iopamidol in peripheral arteriography

Iopamidol, a non-ionic contrast agent, was evaluated during peripheral arteriography in 10 patients. All reported a sensation of warmth during injection. One described the procedure as moderately painful. All objectively tolerated the injections well, and there were no significant changes in clinical or laboratory findings. Vessel opacification was good to excellent in all cases. The authors suggest that non-ionic contrast agents replace ionic agents for peripheral arteriography.

A double-blind controlled evaluation of Actifed and its individual constituents in allergic rhinitis

Pseudoephedrine and triprolidine, administered every 6 hours as a combination, made separate and distinct contributions to the treatment of allergic rhinitis. Furthermore, the combination was perceived by the patients as being clinically superior to either of its components or placebo.

Comparison of complexes containing lysyl-tRNA synthetase from normal and virus-transformed cells

We compared the lysyl-tRNA synthetases from normal (Balb/3T3) and murine sarcoma virus-transformed (KA31) mouse fibroblasts. In agreement with several other reports of mammalian systems, the lysyl-tRNA synthetases from these cells occurred in very large postmicrosomal complexes as determined by gel filtration on agarose columns. Arginyl-, isoleucyl-, methionyl-, phenylalanyl-, and tyrosyl-tRNA synthetases also occurred as part of a large complex or complexes. Activity of glycyl- or leucyl-tRNA synthetase was not detected in a complex. The specific activities of arginyl- and methionyl-tRNA synthetases were three- and five-fold higher, respectively, in a complex from KA31 as compared with a complex from Balb/3T3. In contrast, the specific activity of lysyl-tRNA synthetase from the Balb/3T3 complex was 50% higher than that of the KA31 complex. tRNALys obtained from the complexes of Balb/3T3 and KA31 was fractionated into isoacceptors on columns of RPC-5. The relative amounts of lysine isoacceptors in total preparations of tRNA from normal whole cells and in tRNA obtained from the normal enzyme complex were the same. However, two isoacceptors were present in greater amounts and two were present in lesser amounts in the KA31 enzyme complex as compared with lysine isoacceptors in a total preparation of tRNA from KA31 cells.

Clinical trial of iopamidol for lumbosacral myelography

The results of the initial North American trial of the nonionic, water-soluble contrast medium iopamidol for lumbosacral myelography are reported. The iopamidol was easily visualized by fluoroscopy during introduction, and the radiographic quality of all 12 conventional myelographic examinations was excellent. The diagnoses were herniated nucleus pulposus (seven), traumatic dislocation (one), metastasis (one), and normal (three). One patient had a repeat myelogram with a different hydrosoluble contrast medium 2 months after his iopamidol examination and surgery and showed no radiographic evidence of arachnoiditis. The adverse reactions were all mild and transient: headache (four cases), nausea (two), and leg pain (one). There were no diaphoresis, fever, seizures, hallucinations, agitation, or vital sign changes. Electrocardiography, hematology, and blood chemistries were all normal. In two patients, electroencephalogram changes, three to four bursts of diffuse intermittent rhythmic delta activity with no spiking, were present at 6 hr with return to normal at 24 hr.

Anxiety and sleep after fosazepam

1 Six volunteers of mean age 59 years received placebo for week, then fosazepam (60 mg) nightly for 3 weeks, then placebo for 3 weeks. Subjective ratings and all-night electrophysiological recordings were made. 2 Fosazepam administration improved subjective sleep quality nut impaired feelings of morning vitality. Its withdrawal was associated with anxiety, impaired concentration and continuing impairment of morning vitality. Measured sleep duration increased on fosazepam, sleep was less broken, slow wave sleep stages 3 and 4 diminished in duration and so did REM sleep. 3 Despite the short-life of fosazepam some drug effects persisted for several days after withdrawal, suggesting action of a long half-life metabolite.

Mesoridazine and human sleep

1 Mesoridazine, a phenothiazine of short half-life, and potentially useful as an hypnotic, has here been investigated using volunteers of late middle age. 2 The electrophsiological recording of all-night sleep was studied in seven subjects for a 7-week period during which ther received mesoridazine (10 mg nightly) for 3 weeks. The drug reduced the frequency of transitions into wakefulness and stage 1 (drowsiness) and reduced the time spent in stage 1; there was a withdrawal rebound. Mesoridazine increased REM sleep above baseline levels and a rebound fall below baseline occurred on withdrawal. The drug did not alter the amount of stage 3 + 4 slow wave sleep. 3 Subjective self-ratings were assessed in a 6-week study of sixteen subjects. Sleep quality improved on mesoridazine (10 mg nightly) but there was diminution of zest and freshness 20 min after rising. Daytime concentration and anxiety were rated as not affected either by administration or withdrawal.