Regulation of L-arabinose transport in Salmonella typhimurium LT2

The inducible L-arabinose transport system was characterized in Salmonella typhimurium LT2. Only one L-arabinose transport system with a Km of 2 X 10(-4) M was identified. The results suggested that araE may be the only gene which codes for L-arabinose transport activity under the conditions tested. An araE-lac fusion strain was used to study the induction of the araE gene. No araE expression was detected when the L-arabinose concentration was lower than 1 mM. The expression of araE reached a maximum in the presence of 50 mM L-arabinose, and was significantly reduced in the presence of 50 mM L-arabinose, and was significantly reduced in the presence of D-glucose. Expression of the araBAD and araE genes was coordinately regulated. The concentration of L-arabinose that allowed maximum araBAD gene expression was 50-fold lower in an araE+ strain compared to an araE strain.

DNA sequence of the araBAD-araC controlling region in Salmonella typhimurium LT2

The araB and araC genes of Salmonella typhimurium have been cloned onto the plasmid pBR322. Restriction analysis and subcloning of restriction fragments localized these genes to a 4.4 kb DNA fragment. Complementation analysis revealed that the cloned araB and araC genes from S. typhimurium complemented araB and araC mutant strains of escherichia coli. Conversely, cloned araB and araC genes from E. coli complemented araB and araC mutant strains of Escherichia coli. Conversely, cloned araB and araC genes from E. coli complemented araB and ara C mutant strains of S. typhimurium. The DNA sequence was determined for the S. typhimurium araB and araC controlling region and for the initially translated portions of these genes. The nucleotide sequence of the araB promoter was 87% homologous with the same region in E. coli and contained no deletions or insertions relative to the E. coli sequence. The presumed AUG codon corresponding to the amino terminus of the S. typhimurium araC protein was in the same location as in E. coli. There was, however, considerable divergence for the E. coli sequence preceding the translation start site. The nucleotide sequence of the initial 237 bp in the open reading frame of the S. typhimurium araC gene was 78% homologous with the same sequence in E. coli. By comparison, the amino acid sequence for this region was 91% conserved.

Near-zero-frequency stimulated Raman gain spectroscopy in CS(2)

We have obtained the low-frequency dispersion of Im X((3)) in CS(2) by stimulated Raman gain technique with a simple low-power cw-pulsed laser system. The theoretical relationship between the nonlinear spectrum and the spontaneous spectrum is confirmed. The unique capability of the technique for low-frequency Raman measurements is well demonstrated with the detection of a weak near-zero-frequency mode.

Genetic characterization of the araE gene in Salmonella typhimurium lt2

Six L-arabinose transport-deficient mutants of Salmonella typhimurium LT2 were isolated on the basis of their inability to ferment low concentrations of L-arabinose. The mutations were localized between serA and lys on the S. typhimurium genetic map and assigned to the araE locus. An araE-lac fusion strain was constructed and used to determine that the direction of araE transcription was counterclockwise on the S. typhimurium genetic map. beta-Galactosidase activity was induced by L-arabinose in the araE-lac fusion strain, suggesting that araE expression is controlled at the level of transcription.

A clinical trial with cefoperazone in pneumonia and pyelonephritis

15 cases of pneumonia and 15 cases of pyelonephritis were included in a clinical trial of parenteral cefoperazone. The organisms isolated from patients with bacterial pneumonia were: Staphylococcus aureus (6), Klebsiella pneumoniae (5), Diplococcus pneumoniae (3), Pseudomonas species (2), and 6 others. Amongst those with pyelonephritis, Escherichia coli (12), Enterobacter (1), and 3 other pathogens, were isolated. All were sensitive to cefoperazone. The efficacy of cefoperazone in patients with pneumonia was: good in 11 (73%), fair in 3, and poor in 1. In pyelonephritis, 12 (80%) responded well and in the other 3 response was fair. There were no significant side effects or hypersensitivity reactions.

Ultraviolet laser excitation source

A new intense ultraviolet light source has been developed from an array of hypocycloidal pinch (HCP) devices. The basic unit of the array is constructed with three disk electrodes and is capable of producing dense plasmas at temperatures up to 10,000,000 K. Very high input power levels to the array are possible without significantly shortening its useful life, in strong contrast with conventional xenon flashlamps. The new light source, when operated with Ar and Xe gas mixtures at high pressures (~5 x 10(4) Pa), produced a light output of over 100 MW in the near-UV spectral range and successfully pumped an iodine photodissociation laser at 1.315 microm. A xenon recombination laser at 2.027 microm was also pumped in the HCP array.

Isolation of ara-lac gene fusions in Salmonella typhimurium LT2 by using transducing bacteriophage Mu d (Apr lac)

A specialized Mu transducing phage containing a gene encoding ampicillin resistance and the lac structural genes without the lac promotor [Mu d(apr lac)] has been constructed and used to create gene fusions in Escherichia coli (M. J. Cadadaban and S. N. Cohen, Proc. Natl. Acad. Sci. U.S.A. 76:4530--4533, 1979). Transposition of the Mu d(Apr lac) phage to chromosomal sites can result in lac expression being controlled by a chromosomal promoter. We have constructed an Escherichia coli K-12 strain in which the Mu d(Apr lac) phage is integrated into an F factor. The F+::Mu d(Apr lac) was then transferred by conjugation into a Salmonella typhimurium strain that was sensitive to L-arabinose. Strains containing gene fusions were selected as L-arabinose-resistant colonies after partial induction of the phage. Two classes of ara-lac fusion strains were isolated: (i) araC-lac fusions in which the expression of beta-galactosidase synthesis was constitutuve and not inducible by L-arabinose; and ((ii) fusion of the lac genes to the ara structural genes in which the expression of beta-galatosidase synthesis was induced 263-fold by L-arabinose.

Clonidine on the pressor response to raised intracranial pressure

We attemptedto clarify the mechanism of the pressor response to raised intracranial pressure (ICP) in urethane-anesthetized rabbits. Intraventricular clonidine inhibited the pressor response to raised ICP, and intraventricular phentolamine antagonized the inhibitory effect of clonidine on the pressor response. In reserpine-treated rabbits the pressor response to raised ICP was not observed. Following intraventricular norepinephrine, however, the pressor response was observed. Intraventricular clonidine inhibited the pressor response that could be observed in the reserpine-treated rabbits following the intraventricular norepinephrine. These results suggest that the central sympathetic neurons play an important role in producing the pressor response to raised ICP.

Effect of antiparkinsonian medication on plasma levels of chlorpromazine

Twenty-one chronic schizophrenics were stabilized with chlorpromazine therapy at their therapeutic dosage for one month. Trihexyphenidyl hydrochloride or identical placebo was then added according to a double-blind, split crossover design. The duration of each half of the crossover was 15 days. Steady state blood samples were drawn three times weekly during the experimental period and the amount of chlorpromazine was determined. The results indicated there were no differences in the levels obtained between the trihexyphenidyl and the placebo phases. A two-hour postdrug blood sample was also drawn at the end of each phase and again, there were no differences between the two conditions. The importance of these results is discussed.

A rating scale for tardive dyskinesia

A rating scale for tardive dyskinesia was developed, consisting of nearly all signs seen by two groups of investigators over a 5-year period. Thirty-four items were included in the scale with a possibility of writing in idiosyncratic signs. The scale was shown to have good reliability and validity in studies carried out by both the New York and Boston groups. It is recommended as a suitable instrument for describing the breadth of tardive dyskinesia syndrome and also for quantifying the disorder. A second scale, "the abbreviated dyskinesia scale", contains 13 items which are more global than the items in the original scale. It also has been shown to be both reliable and valid. Its use is suited to situations requiring less extensively detailed assessments.

Adequacy of endoscopic biopsy specimens for disaccharidase assays

Intestinal mucosa from 40 patients obtained by fiber-endoscopic biopsy was assayed for disaccharidases to determine suitability of this tissue for assay. The combined specimens from each patient provided 4.7-38.7 mg of tissue, adequate in all instances for duplicate determinations of protein, lactase, sucrase, and maltase. Tissue remained for assays of palatinase in 39 instances, trehalase and cellobiase in 37, and alkaline phosphatase in 22 cases. Twenty-four subjects had normal lactose tolerance tests and normal sucrase/lactase ratios. Thirteen patients with abnormal oral lactose tolerance tests were identified as having a primary low lactase activity on the basis of elevated sucrase/lactase ratios. This ratio was most helpful in making the diagnosis of a primary low lactase, since the mucosal specimens were not obtained from comparable areas. Tissue from three subjects with an abnormally low maltase was unsuitable for diagnosis. Endoscopic biopsy of mucosa appears to be satisfactory for disaccharidase assays in most instances.

Evaluation of a slow-release lithium carbonate formulation

A slow-release lithium preparation was compared with a standard formulation in normal volunteers and in patients. Pharmacokinetic parameters of normal volunteers were examined after a single dose of each form and the steady-state levels after a b.i.d. dose of the slow-release form. These initial single-dose data suggested that the two formulations are not bioequivalent. However, the area under the curve of the two forms was similar, and the essentially complete recovery of lithium from urine in steady state indicates equal bioavailability. The patients' steady-state levels for the two formulations essentially confirmed the normal subjects' data: with the slow-release form plasma lithium levels were slightly higher, and the postdose lithium level variability was decreased by as much as 50%.

Tardive dyskinesia and psychotropic drug history

The adult population of a large mental hospital was screened for tardive dyskinesia (TD). Approximately 11% of the hospital population showed signs of TD; females and the elderly were over-represented in the TD group. A representative sample of those with TD was selected and a control (non-TD) patient was chosen to match each of the TD subjects in age, sex, length of hospitalization, diagnosis, and race. The charts of these subjects were searched for any indices of brain damage and the complete psychotropic medication history was recorded. There was no difference between the TD and controls in the amount of psychotropics ingested, in the duration of administration, in the kinds of drugs, or in the organicity history. Women as a group, however, tended to have more polypharmacy than men. The role of neuroleptics in TD is discussed as well as other possible etiological factors.

Loxapine succinate as a neuroleptic agent: evaluation in two populations of elderly psychiatric patients

Loxapine succinate, a newly developed neuroleptic drug, was administered to two groups of geropsychiatric patients: (a) 12 with psychosis and organic brain syndrome, and (b) 14 with chronic schizophrenia. After a two-week baseline period, loxapine was given for 12 weeks. The moderate therapeutic effect of loxapine in the "responders" was similar to that of other neuroleptic drugs. The therapeutic dosage range was found to be from 10 to 80 mg daily--about half that used for younger patients. The chief side effects were drowsiness, mild extrapyramidal symptoms, and a slight increase in blood pressure.

High- and low-potency neuroleptics in elderly psychiatric patients

The efficacy and side effects of a low-potency neuroleptic, thioridazine hydrochloride, and those of a high-potency neuroleptic, fluphenazine hydrochloride, were compared in 30 elderly chronic schizophrenic patients. Through a crossover design, each patient received both drugs with an intervening washout period. Although both drugs produced a similar degree of improvement, their side effects differed. Fluphenazine caused slightly more extrapyramidal effects than thioridazine, though few occurred with use of either drug. Thioridazine caused weight gain, blood pressure decreases, and ECG changes. High-potency neuroleptic agents appear to be the drugs of choice for elderly schizophrenic patients.

Clinical and plasma level characteristics of intramuscular and oral loxapine

The intramuscular and oral forms of loxapine succinate were compared in their clinical, side effect, and blood level characteristics in ten hospitalized chronic schizophrenic patients. The first phase of the study determined the single dose that produced moderate sedation (i.e., the sedation threshold), and this dose was essentially the same for the two forms. Continuous administration of the two forms using the individualized sedation threshold dosage also failed to indicate any clinical or side effect differences in the two forms. The blood level characteristics, however, did differ between the two forms. The kinetic studies indicated that there was a larger are under the loxapine curve with the intramuscular form than with the oral form, while the 8-OH loxapine area was larger with the oral form. The steady-state studies also showed that the i.m. form had higher loxapine levels than the oral form. The significance of these findings, both clinically and in terms of the relative activity of loxapine and its metabolites, is discussed.