Fluorine-19 NMR studies of the thermal unfolding of 5-fluorouracil-substituted Escherichia coli valine transfer RNA

19F NMR spectroscopy was used to monitor the thermal unfolding of E. coli tRNAVal labeled by incorporation of 5-fluorouracil (FUra). With rising temperatures, resonances in the 19F NMR spectrum of (FUra)tRNAVal gradually shift towards the central region of the spectrum and merge into a single broad peak above 85 degrees C. FU55 and FU12 are the first to shift, beginning at temperatures below 40 degrees C, which suggests that the initial steps of thermal denaturation of tRNAVal involve disruption of the tertiary interactions between the D- and T-arms. The acceptor stem and the FU64-G50 wobble base pair in the T-stem are particularly stable to thermal denaturation. A temperature-dependent splitting of the 19F resonance assigned to FU64, at temperatures above 40 degrees C, suggests that the T-arm of (FUra)tRNAVal exists in two conformations in slow exchange on the NMR time scale.

Radionuclide blood pool scintigraphy in a child with intestinal arteriovenous malformation (juvenile angiodysplasia). A case report and review of the literature

Arteriovenous (AV) malformation or angiodysplasia of the gastrointestinal tract is a very rare cause of bleeding in children. These lesions are congenital anomalies and thought to be of hamartomatous origin. We report on a 4-year-old child with an AV malformation of the distal ileum treated by local resection. A brief review of the relevant literature is included. The importance of radionuclide blood pool scanning in the evaluation of these patients is emphasized.

An unusual case of factitious arthritis

Factitious arthritis is an unusual manifestation of a factitious illness. We report a case of factitious arthritis after the self insertion of needles and fragments of metallic paper clips into the knee joint area. The case illustrates an unusual presentation of Munchausen's syndrome.

Schwannoma of the brachial plexus mimicking an apical lung tumor

Primary tumors of the brachial plexus are unusual. We describe a patient with a large schwannoma of the lower trunk of the brachial plexus that had the radiologic appearance of an apical lung mass. Use of a posterior subscapular approach as well as intraoperative nerve action potential recording permitted resection with spared function.

Improvement of psoriatic arthritis in a patient treated with bromocriptine for hyperprolactinemia

We describe a woman with psoriatic arthritis who experienced a remarkable improvement of her skin and joint disease while only taking bromocriptine therapy. She was treated with bromocriptine for primary infertility due to hyperprolactinemia. The improvement in joint symptoms appeared to parallel that of the skin. More studies are required to determine the reproducibility of this observation.

Recognition of Escherichia coli valine transfer RNA by its cognate synthetase: a fluorine-19 NMR study

Interactions of 5-fluorouracil-substituted Escherichia coli tRNAVal with its cognate synthetase have been investigated by fluorine-19 nuclear magnetic resonance. Valyl-tRNA synthetase (VRS) (EC 6.1.1.9), purified to homogeneity from an overproducing strain of E. coli, differs somewhat from VRS previously isolated from E. coli K12. Its amino acid composition and N-terminal sequence agree well with results derived from the sequence of the VRS gene [Heck, J.D., & Hatfield, G.W. (1988) J. Biol. Chem. 263, 868-877]. Apparent KM and Vmax values of the purified VRS are the same for both normal and 5-fluorouracil (FUra)-substituted tRNAVal. Binding of VRS to (FUra)tRNAVal induces structural perturbations that are reflected in selective changes in the 19F NMR spectrum of the tRNA. Addition of increasing amounts of VRS results in a gradual loss of intensity at resonances corresponding to FU34, FU7, and FU67, with FU34, at the wobble position of the anticodon, being affected most. At higher VRS/tRNA ratios, a broadening and shifting of FU12 and of FU4 and/or FU8 occur. These results indicate that VRS interacts with tRNAVal along the entire inside of the L-shape molecule, from the acceptor stem to the anticodon. Valyl-tRNA synthetase also causes a splitting of resonances FU55 and FU64 in the T-loop and stem of tRNAVal, suggesting conformational changes in this part of the molecule. No 19F NMR evidence was found for formation of the Michael adduct between VRS and FU8 of 5-fluorouracil-substituted tRNAVal that has been proposed as a common intermediate in the aminoacylation reaction.

Dead Sea bath salts for the treatment of rheumatoid arthritis

Thirty patients with classical or definite rheumatoid arthritis were randomly divided into two groups of fifteen patients each of similar age, sex, duration and severity of disease, and medical treatment. All patients were treated once a day with bath salts heated to 35 degrees C for twenty minutes. Group I received Dead Sea bath salts and Group II, the control group, received sodium chloride (NaCl). The study was double-blind and of two weeks' duration. All patients were evaluated by one rheumatologist both before treatment, and two weeks later at the end of the treatment period. Follow-up evaluations were made one and three months after conclusion of the treatments. The clinical parameters evaluated included duration of morning stiffness, fifteen meter walk time, hand-grip strength, activities of daily living, circumference of proximal interphalangeal joints, number of active joints, Ritchie index and the patient's own assessment of disease activity. The laboratory parameters evaluated included erythrocyte sedimentation rate and serum levels of amyloid A, rheumatoid factor, sodium, potassium, calcium and magnesium. A statistically significant improvement (p less than 0.01 or p less than 0.05) was observed in Group I only, in most of the clinical parameters assessed. Maximal therapeutic effect was obtained at the end of the treatment and lasted up to one month.

Sulphur bath and mud pack treatment for rheumatoid arthritis at the Dead Sea area

Forty patients with classical or definite rheumatoid arthritis in a stage of active disease were treated for two weeks at a spa hotel. The patients were divided into four groups of 10. Group I was treated with daily mud packs, group II with daily hot sulphur baths, group III with a combination of mud packs and hot sulphur baths, and group IV served as a control group. The patients were assessed by a rheumatologist who was blinded to the treatment modalities. Statistically significant improvement for a period of up to three months was observed in the three treatment groups in most of the clinical indices. Improvement in the control group was minor in comparison and not statistically significant. No significant improvement was observed in any of the laboratory variables measured. Except for three mild cases of thermal reaction there were no side effects.

Palindromic rheumatism in Israel--a disease entity? A survey of 34 patients

Over a period of 10 years 34 patients were diagnosed as suffering from palindromic rheumatism. Eighty-one percent of the patients were of North African origin. This is significantly higher (p = 0.01) than the age-adjusted origin of the general population in the region. Attacks were usually monoarthritic or oligoarthritic in nature. The joint most often involved was the knee. Prophylactic therapy with colchicine was ineffective. Gold salts brought about partial remission in three of six patients. Despite a relatively long average follow-up period of 9.3 years and the finding of a positive rheumatoid factor in 12% of the patients, not one of the patients developed rheumatoid arthritis. In 50% of the patients we detected an unexplained elevation in serum globulins and immunoglobulins. The possible association between this syndrome and Familial Mediterranean Fever is discussed.

Induction of de novo synthesis of crystalline lenses in aphakic rabbits

The mammalian lens, like other ectodermal tissues, can regenerate itself given the proper environment. Endocapsular phacoemulsification of adult rabbit lenses was performed. A lens capsular bag with posterior and anterior lens capsule relatively intact was left in the eye. Regrowth of material in the capsular bag was followed by slit lamp biomicroscopy and photography over a 12-month period. Histopathology of the new material showed regions of relatively normal epithelial cells and lens fibers as well as regions where growth was irregular. All major lens crystallin classes were present in the regenerated lens. Several specific crystallin subunits, known to arise by post-translational modification of primary gene products, were absent or present in abnormally low concentrations.

19F NMR of 5-fluorouracil-substituted transfer RNA transcribed in vitro: resonance assignment of fluorouracil-guanine base pairs

5-Fluorouracil is readily incorporated into active tRNA(Val) transcribed in vitro from a recombinant phagemid containing a synthetic E. coli tRNA(Val) gene. This tRNA has the expected sequence and a secondary and tertiary structure resembling that of native 5-fluorouracil-substituted tRNA(Val), as judged by 19F NMR spectroscopy. To assign resonances in the 19F spectrum, mutant phagemids were constructed having base changes in the tRNA gene. Replacement of fluorouracil in the T-stem with cytosine, converting a FU-G to a C-G base pair, results in the loss of one downfield peak in the 19F NMR spectrum of the mutant tRNA(Val). The spectra of other mutant tRNAs having guanine for adenine substitutions that convert FU-A to FU-G base pairs all have one resonance shifted 4.5 to 5 ppm downfield. These results allow assignment of several 19F resonances and demonstrate that the chemical shift of the 19F signal from base-paired 5-fluorouracil differs considerably between Watson-Crick and wobble geometry.

Linear scleroderma, hemiatrophy and systemic lupus erythematosus

A young woman, with linear scleroderma accompanied by body hemiatrophy since childhood, developed systemic lupus erythematosus. The rare coexistence of the 2 diseases is discussed.

All perforated ulcers are not alike

To determine if ulcer location and other clinical factors affect the hospital course and early outcome of patients with perforated peptic ulcers in the decade since the introduction of H2 receptor antagonists, the records of 80 patients with perforated peptic ulcers were analyzed. Demographic factors, clinical features, and the outcome of patients with duodenal ulcer perforation were similar to patients with prepyloric ulcer perforation. In contrast, patients with gastric ulcer perforation had differing characteristics from the group with perforated pyloroduodenal ulcers. Overall, NSAID use preceded perforation in one half of the patients; severe coexisting medical illness and a short interval of symptoms before perforation were seen in more than one half of patients. Gastric ulcer location, hemodynamic instability, greater degree of peritoneal contamination, and larger ulcer size were factors associated with increased rates of mortality. Overall mortality rate was 12.5% and rate of morbidity was 33%. Oversewing with or without omental patch was the operation most commonly employed by a diverse group of surgeons.

Interleukin 6 gene expression in normal and neoplastic B cells

In the present report we demonstrate that the IL-6 gene is expressed in anti-Ig-activated and neoplastic B cells. After activation with anti-Ig, splenic B cells rapidly expressed IL-6 mRNA with peak expression occurring at 4 h and declining rapidly thereafter. In an attempt to exclude that the IL-6 mRNA expression was in non-B cells, T cells and monocytes were extensively depleted. In this highly purified B cell population, IL-6 mRNA was retained, whereas the expression of the T cell- and monocyte-restricted CD2 and CD14 genes was nearly undetectable. These results are consistent with the conclusion that activated B cells express IL-6 mRNA. Because we found IL-6 mRNA expression in normal activated B lymphocytes, we examined the expression of IL-6 mRNA in B cell neoplasms. 11 of 25 non-Hodgkins B cell lymphomas and 4 of 4 myelomas and plasma cell leukemias expressed IL-6 mRNA, whereas only 1 of 19 B cell leukemias was positive. To exclude that IL-6 mRNA expression in neoplastic B cells was the result of contaminating non-B cells, T cells and monocytes were extensively depleted from the tumor specimens. In the three IL-6-positive tumor samples depleted of T cells and monocytes, IL-6 mRNA expression was retained in all cases. These observations provide support for the idea that the IL-6 gene is expressed in normal activated and neoplastic B cells.

Plasma atrial natriuretic peptide in patients with acute myocardial infarction: effects of streptokinase

Plasma concentrations of immunoreactive atrial natriuretic peptide (mean (SEM] were measured in 135 patients admitted to two coronary care units with myocardial infarction, ischaemic chest pain, or non-ischaemic chest pain. Concentrations were significantly higher in patients with acute myocardial infarction not treated with systemic thrombolysis (60.4 (14.3) pg/ml) than in patients with non-ischaemic chest pain (21.1 (4.3) pg/ml). Patients with ischaemic chest pain had intermediate values (39.3 (7.1) pg/ml). Patients with acute myocardial infarction treated with intravenous streptokinase had normal concentrations of plasma atrial natriuretic peptide (20.2 (3.6) pg/mg), which were significantly lower than those in patients with myocardial infarction not given streptokinase. These changes could not be explained by factors such as age, pre-existing hypertension, renal dysfunction, or cardiac failure, nor treatment other than streptokinase. Raised plasma concentrations of atrial natriuretic peptide in acute myocardial infarction may be a homoeostatic response acting to reduce atrial pressures by natriuresis, diuresis, and venodilatation. The lower concentrations of atrial natriuretic peptide in patients with acute myocardial infarction treated with streptokinase may reflect a short term beneficial haemodynamic effect of streptokinase.

Toxic waste: behavioral effects of an environmental stressor

This study examines the stress-related behavioral effects that may be associated with living near an ambient stressor: a toxic-waste landfill. Results are based on a telephone survey of 426 persons living in three distance strata from the landfill (within 1 1/2 miles, 1 1/2 to 5 miles, and 5 to 10 miles). The instrument was adapted from the Hopkins Life Checklist (SCL-90) and from surveys used by researchers studying the effects of the Three Mile Island nuclear accident. No significant differences were found across area or amount of stimuli exposure on the dependent variables of bodily effects, anger-hostility, and demoralization. Scattered effects across age, sex, educational level, and home ownership (v rental) occurred; however, these could not be attributed solely to the landfill.

Septal rupture: effect of oxygen administration

A patient with interventricular septal rupture as a complication of myocardial infarction was studied to determine whether varying the concentration of inspired oxygen would alter the magnitude of intracardiac shunt. A significant correlation was found showing that high concentration of inspired oxygen results in increased left to right shunting probably due to systemic vasoconstriction and pulmonary vasodilatation.

Dermabrasion of traumatic tattoos: simple, inexpensive, effective

In this article we describe the use of an electrosurgical cautery tip scratch pad for the treatment of traumatic (adventitious) tattoos. This inexpensive item is available in most surgical operating rooms. The pad is flexible yet firm and obviates the need for power equipment. Most important, the technique is simple, easy to learn, and highly effective.

Thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome in three siblings

Two brothers and one sister had three variants of thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome (the 'TTP-HUS' complex). The sister had a chronic fatal variant of thrombotic thrombocytopenic purpura with severe neurological manifestation. One brother had a chronic relapsing disease but the kidneys were not affected, and the other brother had haemolytic uraemic syndrome. This occurrence in one family supports the hypothesis that haemolytic uraemic syndrome and thrombotic thrombocytopenic purpura are actually two variants of the same disease.

Serum and synovial fluid levels of serum amyloid A protein and C-reactive protein in inflammatory and noninflammatory arthritis

Serum and synovial fluid (SF) levels of serum amyloid A (SAA) and C-reactive protein (CRP) were measured in 46 cases of various inflammatory arthritis (Group 1), and in 40 cases of noninflammatory arthritis: 18 cases of osteoarthritis (Group 2) and 22 cases of traumatic arthritis (Group 3). Serum and SF SAA levels were markedly elevated in Group 1: 126.4 micrograms/ml +/- 19.2 SEM and 46.4 micrograms/ml +/- 10.5 SEM, respectively; moderately elevated in Group 2: 10.1 micrograms/ml +/- 2.9 SEM, 4.0 micrograms/ml +/- 1.1 SEM and moderately elevated in Group 3: 10.4 micrograms/ml +/- 1.2 SEM, 4.0 micrograms/ml +/- 1.2 SEM, respectively. Serum/SF SAA ratios were similar in all 3 groups and ranged between 2.52-2.72. In comparison to SAA, the increment of serum and SF CRP above normal levels was moderate. A positive strong correlation was found between serum SAA and serum CRP: r = 0.64 (p less than 0.001) and between SF SAA and SF CRP: r = 0.59 (p less than 0.0001). SF SAA did not correlate with the number of SF white blood cells but did correlate with the percent of SF polymorphonuclear cells: r = 0.23 (p less than 0.05).

Partial assignment of resonances in the 19F nuclear magnetic resonance spectra of 5-fluorouracil-substituted transfer RNAs

Features of the 19F nuclear magnetic resonance (NMR) spectra of three purified 5-fluorouracil-(FUra-) substituted Escherichia coli tRNAs, tRNA(1Val), tRNA(mMet), and tRNA(fMet), are compared. Each of the tRNA species can be resolved into two isoaccepting forms, A and B, whose 19F NMR spectra differ in the shift of one peak from the 4.5 to 4.8 parts per million (ppm) range (FUra = O) in the spectrum of isoacceptor B upfield to ca. -15 ppm in that of isoacceptor A. Because the sequences of the two isoacceptors of each tRNA differ only at one position in the D loop, that normally occupied by a dihydrouridine residue, we assign the 4.5 ppm peak in the spectrum of fluorine-labeled tRNA(1Val) to FUra17 and the resonance at 4.6 ppm in the spectrum of fluorouracil-substituted tRNA(mMet) to FUra20. A reciprocal 19F[19F] nuclear Overhauser effect is observed between the downfield peaks A and B in the 19F NMR spectrum of 19F-labeled tRNA(1Val). Assuming that fluorine-labeled tRNA(1Val) has a structure similar to that of yeast tRNA(Phe), only FUra54 and -55 are close enough (4-5 A) to give an appreciable 19F homonuclear Overhauser effect. Peaks A and B have therefore been assigned to FUra54 and -55. As the temperature is raised from 30 to 45 degrees C, the intensity of peak B (6.6 ppm) in the spectrum of 19F-labeled tRNA(1Val) gradually shifts upfield to 6.4 ppm (Tm = 36 degrees C), indicating a temperature-dependent slow exchange of the corresponding 5-fluorouracil residue between two magnetically distinct environments.(ABSTRACT TRUNCATED AT 250 WORDS)

[Improvement of a chromosomal technic for trophoblast biopsy. Apropos of 200 cases]

The authors report their experience of 200 cases of prenatal diagnosis by biopsy of chorionic villi. Because they could not consistently obtain good quality chromosome banding, they propose a modification of the conventional direct method. The addition of methanol in sufficient proportions to the nuclear suspension makes it possible to obtain spontaneous spreading on slides heated to 65 degrees C and eliminates the problems of mechanical spreading.

Quinidine-induced lupus erythematosus-like syndrome: three case reports and a review of the literature

Three patients with an LE-like syndrome secondary to quinidine are described. Twenty-two similar cases are reviewed. The clinical picture is characterized mainly by polyarthritis, pleuritis, fever and dermatitis. The common laboratory findings are positive antinuclear antibodies, absence of anti-DNA antibodies, thrombocytopenia, leukopenia and abnormal liver function tests. This LE-like syndrome may appear within days or up to several years after the start of quinidine treatment and disappears completely a few weeks after discontinuation of the drug.

Cardiovascular manifestations of ankylosing spondylitis

In a retrospective study, 40 patients with ankylosing spondylitis were assessed for extraspinal manifestations. Cardiovascular complications were found in 17 patients (42.5%): 5 (12.5%) had aortic insufficiency, 3 (7.5%) had atrioventricular block and 5 (12.5%) had bundle branch block. Wolff-Parkinson-White syndrome was diagnosed in one case and short PR syndrome in another. Cardiovascular complications were more common in patients with longer disease duration. Ischemic heart disease was found in 17.5% of the cases and pulmonary fibrosis in 15%. Peripheral arthritis was found in 42.5% and its prevalence did not differ in patients with or without cardiac involvement.

Erythema nodosum in the Negev area--a survey of 50 patients

Fifty patients in the Negev area with erythema nodosum (EN) were studied retrospectively. The clinical picture and demographic characteristics did not differ markedly from those in the literature. In contrast to most European studies but like those from Egypt, we found streptococcal pharyngitis to be the major cause of EN. Conspicuously, sarcoidosis is a rare cause of EN in the Negev. The low incidence of EN in the Negev--2 cases/100,000 people per year--as opposed to Europe--14 cases/100,000 people per year--is hardly explained by the low occurrence of sarcoidosis in Israel. Other factors, unknown at present, may account for this low incidence.

19F nuclear magnetic resonance as a probe of anticodon structure in 5-fluorouracil-substituted Escherichia coli transfer RNA

The use of 19F nuclear magnetic resonance (n.m.r.) spectroscopy as a probe of anticodon structure has been extended by investigating the effects of tetranucleotide binding to 5-fluorouracil-substituted Escherichia coli tRNA(Val)1 (anticodon FAC). 19F n.m.r. spectra were obtained in the absence and presence of different concentrations of oligonucleotides having the sequence GpUpApX (X = A,G,C,U), which contain the valine codon GpUpA. Structural changes in the tRNA were monitored via the 5-fluorouracil residues located at positions 33 and 34 in the anticodon loop, as well as in all other loops and stems of the molecule. Binding of GpUpApA, which is complementary to the anticodon and the 5'-adjacent FUra 33, shifts two resonances in the 19F spectrum. One, peak H (3.90 p.p.m.), is also shifted by GpUpA and was previously assigned to FUra 34 at the wobble position of the anticodon. The effects of GpUpApA differ from those of GpUpA in that the tetranucleotide induces the downfield shift of a second resonance, peak F (4.5 p.p.m.), in the 19F spectrum of 19F-labeled tRNA(Val)1. Evidence that the codon-containing oligonucleotides bind to the anticodon was obtained from shifts in the methyl proton spectrum of the 6-methyladenosine residue adjacent to the anticodon and from cleavage of the tRNA at the anticodon by RNase H after binding dGpTpApA, a deoxy analog of the ribonucleotide codon. The association constant for the binding of GpUpApA to fluorinated tRNA(Val)1, obtained by Scatchard analysis of the n.m.r. results, is in good agreement with values obtained by other methods. On the basis of these results, we assign peak F in the 19F n.m.r. spectrum of 19F-labeled tRNA(Val)1 to FUra 33. This assignment and the previous assignment of peak H to FUra 34 are supported by the observation that the intensities of peaks F and H in the 19F spectrum of fluorinated tRNA(Val)1 are specifically decreased after partial hydrolysis with nucleass S1 under conditions leading to cleavage in the anticodon loop. The downfield shift of peak F occurs only with adenosine in the 3'-position of the tetranucleotide; binding of GpUpApG, GpUpApC, or GpUpApU results only in the upfield shift of peak H. The possibility is discussed that this base-specific interaction between the 3'-terminal adenosine and the 5-fluorouracil residue at position 33 involves a 5'-stacked conformation of the anticodon loop. Evidence also is presented for a temperature-dependent conformational change in the anticodon loop below the melting temperature of the tRNA.

Mobility of individual 5-fluorouridine residues in 5-fluorouracil-substituted Escherichia coli valine transfer RNA. A 19F nuclear magnetic resonance relaxation study

19F nuclear magnetic resonance (n.m.r.) relaxation parameters of 5-fluorouracil-substituted Escherichia coli tRNA(Val)1 were measured and used to characterize the internal mobility of individual 5-fluorouridine (FUrd) residues in terms of several models of molecular motion. Measured relaxation parameters include the spin-lattice (T1) relaxation time at 282 MHz, the 19F(1H) NOE at 282 MHz, and the spin-spin (T2) relaxation time, estimated from linewidth data at 338 MHz, 282 MHz and 84 MHz. Dipolar and chemical shift anisotropy contributions to the 19F relaxation parameters were determined from the field-dependence of T2. The results demonstrate a large chemical shift anisotropy contribution to the 19F linewidths at 282 and 338 MHz. Analysis of chemical shift anisotropy relaxation data shows that, relative to overall tumbling of the macromolecule, negligible torsional motion occurs about the glycosidic bond of FUrd residues in 19F-labeled tRNA(Val)1, consistent with the maintenance of base-base hydrogen-bond and/or stacking interactions at all fluorouracil residues in the molecule. The dipolar relaxation data are analyzed by using the "two-state jump" and "diffusion in a cone" formalisms. Motional amplitudes (theta) are interpreted as being due to pseudorotational fluctuations within the ribose ring of the fluorinated nucleoside. These amplitudes range from approximately 30 degrees to 60 degrees, assuming a correlation time (tau i,2) of 1.6 ns. By using available 19F n.m.r. assignment data for the 14 FUrd residues in 5-fluorouracil-substituted tRNA(Val)1, these motional amplitudes can be correlated directly with the environmental domain of the residue. Residues located in tertiary and helical structural domains show markedly less motion (theta approximately equal to 30 to 35 degrees) than residues located in loops (theta approximately equal to 45 to 60 degrees). A correlation between residue mobility and solvent exposure is also demonstrated. The amplitudes of internal motion for specific residues agree quite well with those derived from X-ray diffraction and molecular dynamics data for yeast tRNA(Phe).

Structure of tobacco genes encoding pathogenesis-related proteins from the PR-1 group

Infection of Samsun NN tobacco with tobacco mosaic virus (TMV) was found to induce the synthesis of mRNA encoding a basic protein with a 67% amino acid sequence homology to the known acidic pathogenesis-related (PR) proteins 1a, 1b and 1c. By Southern blot hybridization it was shown that the tobacco genome contains at least eight genes for acidic PR-1 proteins and a similar number of genes encoding the basic homologues. Clones corresponding to three of the genes for acidic PR-1 proteins were isolated from a genomic library of Samsun NN tobacco. The nucleotide sequence of these genes and their flanking sequences were determined. One clone was found to correspond to the PR-1a gene; the two other clones do not correspond to known TMV-induced PR-1 mRNA's and may represent silent genes. Compared to the PR-1a gene, these genes contain an insertion or deletion in the putative promoter region and mutations affecting the PR-1 reading frame.

Low serum antimycobacterial glycolipid antibody titers in the sera of patients with systemic lupus erythematosus associated with central nervous system involvement

Antibodies which bind to glycolipids derived from Mycobacterium tuberculosis were sought in the sera of patients with systemic lupus erythematosus (SLE), with and without neurological disease, patients with active tuberculosis and normal controls. A significantly lower activity against the mycobacterial glycolipids was detected in the sera of patients with SLE with neurological involvement compared to other patients with SLE or controls. We suggest that low antibody levels against mycobacterial glycolipids may be useful in the diagnosis of patients with SLE in whom involvement of the central nervous system is suspected.

Limited joint mobility and other rheumatological manifestations in diabetic patients

Limited joint mobility was diagnosed in 42.9% of Type I and 37.3% of Type II diabetic patients. Abnormally thick skin was detected in 31.4% of Type I and 33.7% of Type II diabetic patients. Skin abnormalities were observed mainly in patients with L.J.M. There was a high prevalence of hand flexor tendon abnormalities (18.6%). Decreased range of shoulders and hips and flexor tendon abnormalities were significantly more common in patients with LJM. No significant association was found between LJM and grip strength, joint complaints, family history of rheumatic diseases, hypoglycemic attacks, cardiovascular diseases and autonomic neuropathy.

Blood clearance of Streptococcus pneumoniae by C-reactive protein

C-reactive protein (CRP) has long been known to be an acute phase protein associated with infection and various forms of tissue damage. Recent studies have shown that human CRP can be used to passively protect mice from lethal infection with Streptococci pneumoniae. In this study we have undertaken a detailed examination of the ability of human CRP and rabbit CRP (CxRP) to mediate the blood clearance of pneumococci in mice. We have shown that the optimal activity of these acute-phase proteins requires a functioning complement system, and it can take place even in the xid mouse, which has virtually no naturally occurring anti-pneumococcal antibody in its serum. These studies provide additional evidence that CRP may play a protective role in pneumococcal infections, and it may help postpone the development of fatal levels of pneumococci in the blood, long enough for an effective anti-pneumococcal antibody response to be generated.

Blood clearance of Streptococcus pneumoniae by C-reactive protein

C-reactive protein (CRP) has long been known to be an acute phase protein associated with infection and various forms of tissue damage. Recent studies have shown that human CRP can be used to passively protect mice from lethal infection with Streptococci pneumoniae. In this study we have undertaken a detailed examination of the ability of human CRP and rabbit CRP (CxRP) to mediate the blood clearance of pneumococci in mice. We have shown that the optimal activity of these acute-phase proteins requires a functioning complement system, and it can take place even in the xid mouse, which has virtually no naturally occurring anti-pneumococcal antibody in its serum. These studies provide additional evidence that CRP may play a protective role in pneumococcal infections, and it may help postpone the development of fatal levels of pneumococci in the blood, long enough for an effective anti-pneumococcal antibody response to be generated.

Fluorine-19 nuclear magnetic resonance studies of the structure of 5-fluorouracil-substituted Escherichia coli transfer RNA

19F nuclear magnetic resonance has been used to study fully active Escherichia coli tRNA1Val in which 5-fluorouracil has replaced more than 90% of all uracil and uracil-derived modified bases. The 19F spectrum of the native tRNA contains resolved resonances for all 14 incorporated 5-fluorouracils. These are spread over a 6 ppm range, from 1.8 to 7.7 ppm downfield of the standard free 5-fluorouracil. The 19F resonances serve as sensitive monitors of tRNA conformation. Removal of magnesium or addition of NaCl produces major, reversible changes in the 19F spectrum. Most affected is the lowest field resonance (peak A) in the spectrum of the native tRNA. This shifts 2-3 ppm upfield as the Mg2+ concentration is lowered or the NaCl concentration is raised. Thermal denaturation of the tRNA results in a collapse of the spectrum to a single broad peak centered at 4.7 ppm. Study of the pH dependence of the 19F spectrum shows that five incorporated fluorouracils with 19F signals in the central, 4-5.5 ppm, region of the spectrum, peaks C, D, E, F, and H, are accessible to titration in the pH 4.5-9 range. All have pKa's close to that of free 5-fluorouridine (ca. 7.5). Evidence for a conformation change in the tRNA at mildly acidic pHs, ca. 5.5, is also presented. Four of the titratable 5-fluorouracil residues, those corresponding to peaks D, E/F, and H in the 19F spectrum of fluorine-labeled tRNAVal1, are essentially completely exposed to solvent as determined by the solvent isotope shift (SIS) on transfer of the tRNA from H2O to 2H2O. These are also the 5-fluorouracils that readily form adducts with bisulfite, a reagent that reacts preferentially with pyrimidines in single-stranded regions. On the basis of these results, resonances D, E, F, and H in the middle of the 19F spectrum are attributed to 5-fluorouracils in non-base-paired (loop) regions of the tRNA. Evidence from the ionic strength dependence of the 19F spectrum and arguments based on other recent studies with fluorinated tRNAs support earlier suggestions [Horowitz, J., Ofengand, J., Daniel, W. E., & Cohn, M. (1977) J. Biol. Chem. 252, 4418-4420] that the resonances at lowest field correspond to tertiary hydrogen-bonded 5-fluorouracils. Consideration of ring-current effects and the preferential perturbation of upfield 19F resonances by the cyclophotoaddition of 4'-(hydroxymethyl)-4,5',8-trimethylpsoralen, which is known to react most readily with pyrimidines in double-stranded regions, permits initial assignment of upfield resonances to 5-fluorouracils in helical stems.(ABSTRACT TRUNCATED AT 400 WORDS)

Morphological effects of gas compression on the cortical vitreous

We used scanning electron microscopy to study vitreous in normal and perfluorocarbon gas-treated eyes of cynomolgus monkeys. The cortical vitreous of the normal (control) eye appeared to be a lamellar structure composed of sheets of collagen mesh. In the gas-treated eye there was shrinking and tearing of the lamellae. At six and 12 weeks after gas injection there was membrane formation at the edges of the torn lamellae.

Cryoglobulinemia and hepatitis B markers in North African Jews with Raynaud's disease

Mixed cryoglobulinemia was discovered in 11 of 20 patients with Raynaud's disease. Hepatitis B surface markers were found in 10 of these patients with cryoglobulinemia. All patients with cryoglobulinemia were female, and 10 were of northern African origin. This study indicates that, in a population with a high prevalence of hepatitis B infection, mixed cryoglobulinemia is an important etiologic factor in Raynaud's disease.

Fluorine-19 nuclear magnetic resonance study of codon-anticodon interaction in 5-fluorouracil-substituted E. coli transfer RNAs

Codon-anticodon interaction was investigated in fully active 5-fluorouracil-substituted E. coli tRNAVal1 (anticodon FAC) by 19F NMR spectroscopy. Binding of the codon GpUpA results in the upfield shift of a 19F resonance at 3.9 ppm in the central region of the 19F NMR spectrum, whereas trinucleotides not complementary to the anticodon have no effect. The same 19F resonance shifts upfield upon formation of an anticodon-anticodon dimer between the 19F-labeled tRNA and E. coli tRNATyr2 (anticodon QUA). These results permit assignment of the peak at 3.9 ppm to the 5-fluorouracil at position 34 in the anticodon of fluorouracil-substituted tRNAVal1. The methionine codon ApUpG also causes a sequence-specific upfield shift of a peak in the central part of the 19F NMR spectrum of fluorinated E. coli tRNAMetm. However, ApUpG has no effect on the 19F spectrum of 19F-labeled E. coli tRNAMetf, indicating possible conformational differences between the anticodon loop of initiator and chain-elongating methionine tRNAs. 19F NMR experiments detect no binding of CpGpApA to the complementary FpFpCpG (replaces Tp psi pCpG) in the T-loop of 5-fluorouracil-substituted tRNAVal1, in the presence or absence of codon, suggesting that the tertiary interactions between the T- and D-loops are not disrupted by codon-anticodon interactions.