A partial double-blind, placebo-controlled study of electronic dental anaesthesia in children

This study was carried out to determine the effectiveness of electronic dental anaesthesia (EDA) in restorative dental treatment for children. Thirty children were allocated at random to three groups to receive either EDA, a placebo-EDA or anaesthesia by oral injection. One dentist, having introduced and administered these procedures, completed an occlusal restoration in a maxillary permanent first molar in each child. The results showed that the children changed the EDA controls in accordance with pain assessed by their reports and by their facial signs counted in video records by an observer. Both the children and the observer were 'blind' to the difference between EDA and placebo-EDA. There were no statistical differences in: (1) the number of additional oral injections required in all groups to complete treatment, (2) the depth of cavity prepared, (3) the frequency of disruptive activities, (4) the dentist's management behaviour, (5) the dentist's rating of the children's disruptiveness, (6) pain estimated by the children's reports and by facial signs. Treatment time was shortest in the oral injection group, but had no significant correlation with any measure of pain, disruptive behaviour or depth of cavity. It was concluded that EDA was no less effective than anaesthesia administered by injection but, being no more effective than a placebo-EDA, probably worked by distracting the patients.

Langerhan's cell histiocytosis complicating small bowel Crohn's disease

Langerhan's cell histiocytosis is a rare infiltrative disorder of unknown aetiology. A variety of tissues may be affected, but clinically evident intestinal involvement is unusual. An adult patient is described with Crohn's disease of the terminal ileum who subsequently developed Langerhan's cell histiocytosis with extensive infiltration of the small bowel.

Leukemia translocation gene, PLZF, is expressed with a speckled nuclear pattern in early hematopoietic progenitors

The PLZF gene was discovered by studying a rearrangement of the RAR alpha locus in a patient with acute promyelocytic leukemia and a t(11;17) chromosomal translocation. To understand further the potential role(s) of the PLZF gene product in hematopoiesis, we have examined its expression levels in a variety of murine tissues and in established cell lines that are representative of various stages of myeloid and lymphoid development. We show that murine PLZF(mPLZF) is expressed at the highest levels in undifferentiated, multipotential hematopoietic progenitor cells and that its expression declines as cells become more mature and committed to various hematopoietic lineages. Data obtained with established cell lines are corroborated by results showing the lack of human PLZF protein expression in mature peripheral blood mononuclear cells and high PLZF levels in the nuclei of CD34+ human bone marrow progenitor cells. Interestingly, unlike many transcription factors, PLZF protein in these cells possesses distinct punctate nuclear distribution, suggesting its compartmentalization in the nucleus. Taken together, our data suggest a role for PLZF protein in early hematopoiesis and the requirement of downregulation of its expression for proper differentiation of most hematopoietic lineages.

Antigen specificity of the ovine cytotoxic T lymphocyte response to bluetongue virus

Bluetongue virus (BTV), an arbovirus transmitted by midges, can cause serious disease in sheep. Both virus neutralizing antibody and cytotoxic T lymphocytes (CTL) have been shown to have a role in protective immunity. In this study, the antigen specificity of CTL from BTV-immune sheep has been determined using recombinant vaccinia viruses expressing individual BTV antigens. The results show that, in the sheep studied thus far, the serotype-specific outer coat protein, VP2, and the non-structural protein, NS1 are major immunogens for CTL, with VP5 (an outer coat protein) and NS3 being minor immunogens. No VP7 (a major group-reactive inner coat protein) specific CTL were detected. The CTL from sheep immunized with serotype 1 were cross-reactive and able to recognize target cells infected with other BTV serotypes. Further work demonstrated that the cross-reactive CTL recognized NS1, but not VP2.

A morbillivirus that caused fatal disease in horses and humans

A morbillivirus has been isolated and added to an increasing list of emerging viral diseases. This virus caused an outbreak of fatal respiratory disease in horses and humans. Genetic analyses show it to be only distantly related to the classic morbilliviruses rinderpest, measles, and canine distemper. When seen by electron microscopy, viruses had 10- and 18-nanometer surface projections that gave them a "double-fringed" appearance. The virus induced syncytia that developed in the endothelium of blood vessels, particularly the lungs.

Expression of the zinc-finger gene PLZF at rhombomere boundaries in the vertebrate hindbrain

To investigate the potential biological role(s) of the PLZF gene, discovered as a fusion with the RARA locus in a patient with acute promyelocytic leukemia harboring a t(11;17) chromosomal translocation, we have isolated its murine homologue (mPLZF) and studied its patterns of developmental expression. The levels of mPLZF mRNAs increased perinatally in the liver, heart, and kidney, but with the exception of the heart, they were either absent or very low in the adult tissues. In situ analysis of mPLZF expression in mouse embryos between 7.0 and 10.5 days of development revealed that mPLZF mRNAs and proteins were coexpressed in spatially restricted and temporally dynamic patterns in the central nervous system. In the hindbrain region, a segmental pattern of expression correlated with the development of the rhombomeres. From 9.0 days of development, starting first in rhombomeres 3 and 5, there was an ordered down-regulation of expression in the center of each rhombomere, so that 1 day later elevated levels of mPLZF mRNAs and proteins were restricted to cells surrounding the rhombomeric boundaries. The chicken homologue of the PLZF gene, which we have also cloned, demonstrated a similar segmental pattern of expression in the hindbrain. To date, PLZF represents the only example of a transcription factor with elevated expression at rhombomeric boundaries. The high degree of evolutionary conservation between the patterns of PLZF expression during mammalian and avian central nervous system development suggests that it has an important functional role in the regionalization of the vertebrate hindbrain, potentially regulating boundary cell interactions.

Detecting conserved regulatory elements with the model genome of the Japanese puffer fish, Fugu rubripes

Comparative vertebrate genome sequencing offers a powerful method for detecting conserved regulatory sequences. We propose that the compact genome of the teleost Fugu rubripes is well suited for this purpose. The evolutionary distance of teleosts from other vertebrates offers the maximum stringency for such evolutionary comparisons. To illustrate the comparative genome approach for F. rubripes, we use sequence comparisons between mouse and Fugu Hoxb-4 noncoding regions to identify conserved sequence blocks. We have used two approaches to test the function of these conserved blocks. In the first, homologous sequences were deleted from a mouse enhancer, resulting in a tissue-specific loss of activity when assayed in transgenic mice. In the second approach, Fugu DNA sequences showing homology to mouse sequences were tested for enhancer activity in transgenic mice. This strategy identified a neural element that mediates a subset of Hoxb-4 expression that is conserved between mammals and teleosts. The comparison of noncoding vertebrate sequences with those of Fugu, coupled to a transgenic bioassay, represents a general approach suitable for many genome projects.

Effects of SCH 34826, an orally active inhibitor of atrial natriuretic peptide degradation, in healthy volunteers

Atrial natriuretic peptide is cleared from plasma by clearance receptors and by enzymatic degradation by way of a neutral metalloendopeptidase. Inhibition of neutral metalloendopeptidase activity appears to provide an interesting approach to interfere with metabolism of atrial natriuretic peptide to enhance the renal and haemodynamic effects of endogenous atrial natriuretic peptide. In this study, the effects of SCH 34826, a new orally active neutral metalloendopeptidase inhibitor, have been evaluated in a single-blind, placebo-controlled study involving eight healthy volunteers who had maintained a high sodium intake for 5 days. SCH 34826 had no effect on blood pressure or heart rate in these normotensive subjects. SCH 34826 promoted significant increases in excretion of urinary sodium, phosphate, and calcium. The cumulative 5-hour urinary sodium excretion was 15.7 +/- 7.3 mmol for the placebo and 22.9 +/- 5, 26.7 +/- 6 (p less than 0.05), and 30.9 +/- 6.8 mmol (p less than 0.01) for the 400, 800, and 1600 mg SCH 34826 doses, respectively. During the same time interval, the cumulative urinary phosphate excretion increased by 0.3 +/- 0.4 mmol after placebo and by 1.5 +/- 0.3 (p less than 0.01), 1.95 +/- 0.3 (p less than 0.01), and 2.4 +/- 0.4 mmol (p less than 0.001) after 400, 800, and 1600 mg SCH 34826, respectively. There was no change in diuresis or excretion of urinary potassium and uric acid. The natriuretic response to SCH 34826 occurred in the absence of any change in plasma atrial natriuretic peptide levels but was associated with a dose-dependent elevation of urinary atrial natriuretic peptide and cyclic guanosine monophosphate.(ABSTRACT TRUNCATED AT 250 WORDS)

Pea convicilin: structure and primary sequence of the protein and expression of a gene in the seeds of transgenic tobacco

Convicilin, a trimeric globulin of pea (Pisum sativum L.) seeds, is closely related to vicilin and composed of polypeptides of 68.2 kilodaltons. A partial copy DNA (cDNA) clone encoding convicilin was isolated, sequenced, and used to select a convicilin gene from a pea genomic library. A part of the genomic clone was sequenced to obtain the coding sequences missing in the cDNA clone and a further 1 kilobase 5' to the start of transcription were also obtained. The entire sequence of convicilin was deduced from the combined genomic and cDNA sequences. The complete gene encoding convicilin was transferred to tobacco (Nicotiana tabacum L.) and the characteristics of its expression in the seeds of transgenic plants were studied. An unprocessed polypeptide, which was found only in the seeds of the transgenic plants, was identical in size to pea convicilin, and was recognized by vicilin antibodies. Convicilin, which does not undergo posttranslational cleavage in peas, was partially processed to polypeptides of a relative molecular mass (Mr) of approx. 50000 in transgenic tobacco seeds. There was a twofold variation in the level of convicilin accumulated by the mature seeds of a number of transgenic plants and this was well correlated with the number of gene copies incorporated in the different transformants. In the seeds of tobacco plants that contained a single copy of the transferred gene it was estimated that convicilin comprised up to 2% of the seed protein. Thus, using a combination of gene sequencing and expression in a heterologous host we believe we have characterized the gene corresponding to theCvc locus, whereas the gene described by D. Bown et al. (1988, Biochem J.,251, 717-726) probably encodes a minor convicilin-related protein.

Cleaning the people's home: recent developments in Sweden's addiction policy

Legislation has recently been passed in the Swedish parliament to criminalize drug use and widen the powers of the authorities to take adult alcoholics and drug addicts into care. The arguments and debates that have led to these measures are described, drawing on official reports, legislative proposals and parliamentary proceedings. The Swedish attempt to create a drug-free society is linked with recent economic problems, a temperance tradition, and a strong cultural desire for order. These have contributed towards a climate which two pressure groups in particular have manipulated to their advantage.

Kinetics of protein-mediated transfer of rat pancreatic microsomal phosphatidylinositol to liposomes

Pancreatic microsomes were isolated from fasted and pilocarpine-injected rats and the microsomal phosphatidylinositol radiolabelled with myo-[2-3H]inositol by isotopic exchange. A standard reaction mixture was established in which partially purified rat liver phosphatidylinositol exchange proteins sustain a maximal rate of phosphatidylinositol transfer from rat pancreatic microsomes to liposomes. Determination of the transfer kinetics shows (1) that pancreatic microsomal phosphatidylinositol is partitioned approximately equally between a non-exchangeable and a single exchangeable pool and (2) that cholinergic stimulation does not significantly change the relative sizes of the two pools nor the exchange half-life of the latter pool.

Effects of amiloride on oral glucose loading, serum potassium, renin, and aldosterone in diet-controlled diabetes

The effects of amiloride on oral glucose loading, serum potassium, renin, and aldosterone were evaluated in 10 patients with diet-controlled diabetes. Eight had mild hypertension, and 2 had normal blood pressure. Prior to receiving amiloride all were studied for renin and aldosterone responses while supine and after 2 hr ambulation. All had a normal response to change in position in the renin and aldosterone systems. Before administration of amiloride glucose tolerance tests were carried out, with simultaneous determinations for potassium and insulin. Amiloride 5 to 10 mg was given orally for 6 wk. Blood glucose and serum potassium levels were monitored weekly. After 6 wk renin and aldosterone responses were again determined, as were oral glucose tolerance and serum potassium and serum insulin levels. Amiloride did not induce hyperkalemia in these diabetic patients and did not alter the postamiloride relationship. It is concluded that amiloride is safe for patients with an intact renin aldosterone system, more especially those with normal renal function and diet-controlled diabetes mellitus.