A comparison of the visual field restrictions with the M17 series protective mask and the MCU-2/P chemical-biological mask.

The U.S. Air Force and U.

Cytokine production and serum levels in systemic sclerosis.

Serum levels of various cytokines, tumor necrosis factor-alpha (TNF-alpha), interleukin 1-beta (IL1-beta), and interleukin 2 (IL2), and of soluble IL2 receptors (sIL2R) were determined in 30 patients with definite systemic sclerosis (SSc). Spontaneous and lipopolysaccharide-or mitogen-induced production of the cytokines, TNF-alpha, IL1-beta, and IFN-gamma, by peripheral blood mononuclear cells (PBMNC) of these SSc patients was measured by immunoassays. The patients were divided into three groups: 12 with limited cutaneous disease (lcSSc), 7 with diffuse cutaneous disease (dcSSc) < 3 years duration, and 11 with dcSSc > 3 years duration.

Fascia and perichondrium atrophy in tympanoplasty and recurrent middle ear atelectasis.

Fascia and perichondrium grafts to replace and reinforce thin, atrophic tympanic membranes (TMs) are recommended by several authors to correct middle ear atelectasis by forming a fibrous, collapse-resistant TM. This study reviewed the status of connective tissue grafts performed over the 10-year period from 1979 to 1988 to determine if these grafts would maintain sufficient strength and fibrous character to resist recurrent atelectasis. The author used fascia or perichondrium to repair 89 TM defects, and 63 ears were available for follow-up: 54 had cholesteatomas and 9 had perforations.

Lymphokine-activated killer cell and natural killer cell activities in patients with systemic sclerosis.

Objective: To determine the ability of T lymphocytes and natural killer (NK) cells from patients with systemic sclerosis (SSc) to respond to cytokines and to generate immune effector cells.

Methods: The numbers and percentages of peripheral blood T and NK cells were examined by 2-color flow cytometry, and NK and lymphokine-activated killer (LAK) cell function were measured in 4-hour 51Cr-release assays, in 34 patients with SSc. The patients were categorized into 3 subgroups: 10 had diffuse cutaneous disease of less than or equal to 3 years disease duration, 11 had diffuse cutaneous SSc of greater than 3 years duration, and 13 had limited cutaneous disease.

Missense substitutions lethal to essential functions of EF-Tu.

We have used a simple selection and screening method to isolate function defective mutants of EF-Tu. From 28 mutants tested, 12 different missense substitutions, individually lethal to some essential function of EF-Tu, were identified by sequencing. In addition we found a new non-lethal missense mutation.

Peptidyl-tRNA hydrolase is involved in lambda inhibition of host protein synthesis.

Escherichia coli rap mutants do not support vegetative growth of bacteriophage lambda and die upon transcription of lambda DNA bar sites. Bacteria harbouring a pth(ts) mutation synthesize thermosensitive peptidyl-tRNA hydrolase (Pth) and die at 42 degrees C from a defect in protein synthesis. We present evidence that both rap and pth(ts) mutations affect the same gene: (i) peptidyl-tRNA hydrolase activity was found to be defective in rap mutants; (ii) at a threshold temperature, pth cells, like rap mutants, prevented lambda growth and were killed by transcription of cloned bar sites; (iii) sequencing a 1600 bp DNA fragment comprising both loci revealed an ORF located within the limits set by a complementation analysis and encoding a putative polypeptide of 21 kDa; (iv) cloning and sequencing of rap and pth(ts) mutant DNAs both revealed single nucleotide transitions from the wild type ORF sequence, resulting in Arg134 to His and Gly101 to Asp changes respectively.

Visual field restrictions with the M17 series protective mask.

The restrictions on the central and peripheral visual fields, resultant from wearing a M17 series mask, were measured on a subject with normal field of vision. The results showed a decrease in visual field in all meridians, with the nasal area being the most dramatically restricted.

Temporomandibular joint dysfunction syndrome: a close association with systemic joint laxity (the hypermobile joint syndrome).

Sixty-two patients admitted for elective reconstructive surgery of the temporomandibular joint (TMJ) and eight seen as outpatients with a chief complaint of TMJ dysfunction during the same time interval were evaluated for possible etiologic factors contributing to the disease. All hospitalized patients had severe, end-stage degenerative changes within the TMJ, whereas outpatients had less severe disease and did not require surgery. TMJ dysfunction in some patients was said to be a result of established causes including bruxism, malocclusion, and trauma.

The nucleotide sequence of rpsL and its flanking regions in Salmonella typhimurium.

The ribosomal protein (r-protein)-encoding gene, rpsL, and regions flanking it, from Salmonella typhimurium, have been sequenced directly from polymerase chain reaction-amplified chromosomal DNA. The deduced amino acid sequence is identical to that of the Escherichia coli rpsL encoded r-protein. At the nucleotide level, the similarity is 98%, suggesting a strong pressure for the conservation of this important protein.

Mutant ribosomes can generate dominant kirromycin resistance.

Mutations in the two genes for EF-Tu in Salmonella typhimurium and Escherichia coli, tufA and tufB, can confer resistance to the antibiotic kirromycin. Kirromycin resistance is a recessive phenotype expressed when both tuf genes are mutant. We describe a new kirromycin-resistant phenotype dominant to the effect of wild-type EF-Tu.

Antihypertensive and haemodynamic properties of the potassium channel activating (-) enantiomer of cromakalim in animal models.

The present studies describe the blood pressure lowering, and some other haemodynamic effects, of the potassium channel activator, BRL 38227 ((-) enantiomer of cromakalim, CAS 94470-67-4) in various animal models. BRL 38227 was a potent antihypertensive agent following oral administration to conscious spontaneously hypertensive rats, SHR, (0.038, 0.

Suppression of a double missense mutation by a mutant tRNA(Phe) in Escherichia coli.

We report here the isolation of a mutant tRNAPhe that suppresses a double missense auxotrophic mutation in trpA of Escherichia coli, trpA218. The doubly mutant protein product differs from wild-type TrpA by the replacements of Phe22 by Leu and Gly211 by Ser. A partial revertant TrpA phenotype can be obtained from trpA218 by changing either Leu22 back to Phe or Ser211 back to Gly.

Codon context.

The analysis of coding sequences reveals nonrandomness in the context of both sense and stop codons. Part of this is related to nucleotide doublet preference, seen also in non-coding sequences and thought to arise from the dependence of mutational events on surrounding sequence. Another nonrandom context element, relating the wobble nucleotides of successive codons, is observed even when doublet preference, codon usage and bias in amino acid doublets are all allowed for.

A radioactive assay for the physiological activity of the tryptophan synthetase alpha subunit in crude extracts of Escherichia coli.

A modified assay has been devised for the physiological reaction, indole-3-glycerol phosphate to Trp, of the enzyme tryptophan synthetase. The assay may be applied to crude bacterial extracts, and is based on the measurement of incorporation of radioactivity from [3H]Ser into Trp. Comparison with previous colorimetric assays indicates an improvement in sensitivity of about 30-fold, and advantages in terms of sample economy and simplified manipulation.

Mutants of pheV in Escherichia coli affecting control by attenuation of the pheS, T and pheA operons. Two distinct mechanisms for de-attenuation.

Two mutants of pheV, a gene coding for tRNA(Phe) in Escherichia coli, were previously isolated because they affect attenuator control of the pheS, T operon when the mutant pheV genes are carried by the plasmid pBR322. We show that the two mutants (A44 and A46) affect attenuator control by different mechanisms. The effect of mutant A44 on pheS, T expression can be progressively decreased by overproduction of Phe-tRNA synthetase, consistent with the mutant tRNA acting as a competitive inhibitor of the enzyme.

Third position base changes in codons 5' and 3' adjacent UGA codons affect UGA suppression in vivo.

The base sequence around nonsense codons affects the efficiency of nonsense codon suppression. Published data, comparing different nonsense sites in a mRNA, implicate the two bases downstream of the nonsense codon as major determinants of suppression efficiency. However, the results we report here indicate that the nature of the contiguous upstream codon can also affect nonsense suppression, as can the third (wobble) base of the contiguous downstream codon.

Middle ear gas generation in myringoplasties.

No Gelfoam was used to support the vein in 10 simple underlay vein graft myringoplasties. Computed tomographic studies 24 hours postoperatively showed gas filling 75% to 100% of the middle ears in three ears. The epitympanum and mastoid were also evaluated.

CT and MR imaging of intralabyrinthine schwannoma: report of two cases and review of the literature.

Two cases of intralabyrinthine schwannoma were studied with computed tomography (CT) and magnetic resonance (MR) imaging. On CT scans, a soft-tissue mass was identified in the round window niche in both cases. Widening of the basilar turn of the cochlea and characteristic erosion of the promontory were noticed in one case.

Inhibition by glibenclamide of the vasorelaxant action of cromakalim in the rat.

1. In rat isolated thoracic aortic rings pre-contracted with noradrenaline (10(-6) M), cromakalim (3 x 10(-7)-3 x 10(-5) M) produced concentration-related relaxation. This effect was progressively inhibited by increasing concentrations of the anti-diabetic sulphonylurea drug, glibenclamide (10(-6)-10(-5) M).

Interactions between cells of the immune system and hyaluronate synthesis by human dermal fibroblasts.

Mitogen- or alloantigen-activated human peripheral blood mononuclear cells (MNC) produce a soluble factor which selectively stimulates up to twenty-fold the synthesis of glycosaminoglycan (GAG) by cultured normal human fibroblasts. Confluent fibroblast monolayers were incubated with active MNC supernatants and newly synthesized GAG was measured by the incorporation of [3H]glucosamine into cetylpyridinium chloride-precipitable material. The GAG-stimulatory factor (GAG-SF) was a product of T lymphocytes.

Systemic joint laxity (the hypermobile joint syndrome) is associated with temporomandibular joint dysfunction.

A consecutive series of 37 individuals admitted to the hospital for elective temporomandibular joint (TMJ) reconstructive surgery and 3 seen as outpatients with TMJ disease were evaluated for rheumatic disease or for another etiologic factor that might account for this problem. These 40 patients were screened by history, physical examination, and laboratory study. We soon noticed that many patients had generalized joint laxity.

Heterogeneous synthetic phenotype of cloned scleroderma fibroblasts may be due to aberrant regulation in the synthesis of connective tissues.

Clones of dermal fibroblasts from the skin of 4 normal subjects and 5 patients with progressive systemic sclerosis (PSS; scleroderma) were established, and their synthetic and proliferative characteristics were compared. A limiting-dilution assay was used to determine frequencies of cloning in the microcultures of dermal fibroblasts plated. The clones derived from single cells were expanded in vitro and examined (in passages C-H) for growth and synthesis of glycosaminoglycan (GAG) and collagenase-sensitive protein (CSP).

Patent eustachian tube in the underaerated middle ear: a paradox.

Secretory otitis media, middle ear atelectasis, and retraction type cholesteatomas are the most frequently occurring chronic middle ear diseases; and eustachian tube obstruction and the generation of negative or less than atmospheric middle ear pressure is said to be an essential factor in the pathogenesis of these diseases. It has been found that habitual sniffing causes high degrees of negative middle ear pressure in diseased ears; this finding demonstrates eustachian tube patency rather than obstruction. Ears intubated for chronic secretory otitis media, middle ear atelectasis, and cholesteatoma were examined to identify patent eustachian tubes.