CAG trinucleotide RNA repeats interact with RNA-binding proteins

Genes associated with several neurological diseases are characterized by the presence of an abnormally long trinucleotide repeat sequence. By way of example, Huntington's disease (HD), is characterized by selective neuronal degeneration associated with the expansion of a polyglutamine-encoding CAG tract. Normally, this CAG tract is comprised of 11-34 repeats, but in HD it is expanded to > 37 repeats in affected individuals. The mechanism by which CAG repeats cause neuronal degeneration is unknown, but it has been speculated that the expansion primarily causes abnormal protein functioning, which in turn causes HD pathology. Other mechanisms, however, have not been ruled out. Interactions between RNA and RNA-binding proteins have previously been shown to play a role in the expression of several eukaryotic genes. Herein, we report the association of cytoplasmic proteins with normal length and extended CAG repeats, using gel shift and UV crosslinking assays. Cytoplasmic protein extracts from several rat brain regions, including the striatum and cortex, sites of neuronal degeneration in HD, contain a 63-kD RNA-binding protein that specifically interacts with these CAG-repeat sequences. These protein-RNA interactions are dependent on the length of the CAG repeat, with longer repeats binding substantially more protein. Two CAG repeat-binding proteins are present in human cortex and striatum; one comigrates with the rat protein at 63 kD, while the other migrates at 49 kD. These data suggest mechanisms by which RNA-binding proteins may be involved in the pathological course of trinucleotide repeat-associated neurological diseases.

Assisted reproductive technology: a dilemma for the nursing profession

Assisted Reproductive Technology, despite poor outcomes in the treatment of infertility, is poised to take on a new supplementary role to genetic engineering. As an extreme example of medical/reductionist philosophy it is diametrically opposed to the emerging commitment to holism within the nursing profession. Nurses in Australia have been noticeably absent from the debate, research and decision making that has occurred about this technology, yet the implications for professional practice are far-reaching.

Mental rotation of a tactile layout by young visually impaired children

Mental rotation tasks have been used to probe the mental imagery both of sighted and of visually impaired people. People who have been blind since birth display a response pattern which is qualitatively similar to that of sighted people but tend to respond more slowly or with a higher error rate. It has been suggested that visually impaired people code the stimulus and its (or their own) motion in a different way from sighted people-in particular, congenitally blind people may ignore the external reference framework provided by the stimulus and surrounding objects, and instead use body-centred or movement-based coding systems. What has not been considered before is the relationship between different strategies for tactually exploring the stimulus and the response pattern of congenitally blind participants. Congenitally blind and partially sighted children were tested for their ability to learn and recall a layout of tactile symbols. Children explored layouts of one, three, or five shapes which they then attempted to reproduce. On half the trials there was a short pause between exploring and reproducing the layouts. In an aligned condition children reproduced the array from the same position at which they had explored it; in a rotated condition children were asked to move 90 degrees round the table between exploring and reproducing the layout. Both congenitally blind and partially sighted children were less accurate in the rotated condition than in the aligned condition. Five distinct strategies used by the children in learning the layout were identified. These strategies interacted with both visual status and age. We suggest that the use of strategies, rather than visual status or chronological age, accounts for differences in performances between children.

Preterm infant follow-up project: a multi-site field experiment of hospital and home intervention programs for mothers and preterm infants

This study was designed as a multi-site field experiment to test the efficacy of hospital and home visit interventions to improve interaction between mothers and preterm infants. Hospital intervention consisted of State Modulation (SM) treatment, which focused on teaching mothers to read the behavioral cues and modulate the states of consciousness of preterm infants during feedings. Home visit intervention was a field-tested program, Nursing Systems for Effective Parenting-Preterm (NSTEP-P), implemented during the first five months after the infant's hospital discharge. A hospital program on car seats (CS) and standard public health nursing home visits (PHN) served as comparison treatments. The sample consisted of 327 mothers and their preterm infants who were less than 36 weeks of gestational age at hospital discharge. Mothers were randomly assigned to intervention groups on the basis of their education. High education (HE) was > or = 13 years of education, while low education (LE) was < or = 12 years of education. HE mothers were only assigned to hospital programs, while LE mothers were assigned to combinations of hospital and home visit programs. Evaluations were conducted at 40 weeks conceptual age (expected date of birth), at 46 weeks conceptual age (1.5-months-corrected age), and 60 weeks conceptual age (5-months-corrected age). Comparisons were made within each educational group. For HE groups, SM infants gave significantly more clear cues during observations of feeding interactions at 1.5-months-corrected age and teaching interactions at 5-months-corrected age than infants in the CS group. During the teaching interaction, well-educated SM mothers provided significantly more social-emotional and cognitive stimulation than CS mothers. For LE groups, infants in the SM group combined with either PHN or NSTEP-P exhibited significantly more responsive behavior during feeding observations than those infants in the CS/PHN group at 1.5-months-corrected age. LE mothers in the SM/NSTEP-P group demonstrated more sensitivity and more stimulation during teaching interactions at 5-months-corrected age than mothers in the SM/PHN or CS/PHN groups. Findings suggest that State Modulation treatment is effective in influencing positive social interaction of infants regardless of the level of maternal education. State modulation treatment combined with NSTEP-P is most effective in improving the social interaction between preterm infants and mothers with limited formal education. Such treatment-specific programs suggest avenues for providing cost-effective care that complements the changing transactional needs of mothers and preterm infants.

The intricacies of beta-globin gene expression

Gene expression is an extremely complicated process in which several mechanisms are involved. Owing to its developmental and tissue-specific expression, the beta-globin gene is an excellent model for studying gene expression. beta-Globin gene expression involves an interplay between several different mechanisms. Chromatin structure is thought to be altered by the locus control region (LCR) located far upstream of the beta-globin gene locus. As well, multiple transcription factors come into play both in the LCR and in the individual promoters and enhancers of the beta-globin genes. The interaction between these then allows for delicate regulation of beta-globin gene expression. In the following review the elaborate system of beta-globin gene expression will briefly be examined.

Role of gamma delta T cells in murine collagen-induced arthritis

Murine collagen-induced arthritis (CIA) is a T cell-mediated disease which is induced by injection of type II collagen. Previous studies have shown that CD4+ cells which express particular V beta TCR genes are involved in the induction of arthritis in this model. In the present report we demonstrate that CD4-, CD8-, TCR gamma delta cells are present in arthritic joints, expanded in peripheral lymphoid tissue of DBA/1 lac J mice with CIA, and respond in vitro to the anti-TCR gamma delta mAb UC7-13D5 (13D5). In order to directly investigate the role of the gamma delta TCR in murine CIA, DBA/1 lac J mice were injected with 13D5 before or 40 days after injection of type II collagen. Our results demonstrate that i.p. injections of 13D5 initiated 1 day before injection of type II collagen significantly delays both the onset and severity of CIA compared with treatment with type II collagen alone. In contrast, anti-TCR gamma delta mAb injection of arthritic mice 40 days after collagen injection resulted in the rapid onset of severe arthritis which was accompanied by increased bone erosion and cell infiltration into inflamed joints compared with arthritic mice injected with either control hamster IgG or F(ab')2 fragments of 13D5. Arthritic mice injected with intact 13D5 rapidly lost weight, suggesting that 13D5 may induce a cytokine-mediated syndrome similar to that observed in mice and humans after the injection of anti-CD3. Flow cytometry analysis of joint cells isolated after collagenase digestion from arthritic mice demonstrated that 13D5 injection induces the accumulation of CD4-, CD8-, PgP-1 (CD44)+ cells within arthritic joints, whereas arthritic joints from mice injected with control hamster IgG contained cells with a CD4+, CD8- phenotype. CD3+ T cell lines which express the gamma delta TCR from inflamed joints of arthritic mice were established and examined for V gamma usage by the polymerase chain reaction. V gamma 2 rearrangements were predominant in both T cell lines established from inflamed synovium as well as freshly isolated synovial cells from arthritic mice, whereas synovial cells from nonarthritic mice did not demonstrate V gamma 2 rearrangements. Taken together, the results described in this report suggest a direct role for gamma delta TCR T cells in the pathogenesis of CIA in DBA/1 lac J mice.

Role of gamma delta T cells in murine collagen-induced arthritis

Murine collagen-induced arthritis (CIA) is a T cell-mediated disease which is induced by injection of type II collagen. Previous studies have shown that CD4+ cells which express particular V beta TCR genes are involved in the induction of arthritis in this model. In the present report we demonstrate that CD4-, CD8-, TCR gamma delta cells are present in arthritic joints, expanded in peripheral lymphoid tissue of DBA/1 lac J mice with CIA, and respond in vitro to the anti-TCR gamma delta mAb UC7-13D5 (13D5). In order to directly investigate the role of the gamma delta TCR in murine CIA, DBA/1 lac J mice were injected with 13D5 before or 40 days after injection of type II collagen. Our results demonstrate that i.p. injections of 13D5 initiated 1 day before injection of type II collagen significantly delays both the onset and severity of CIA compared with treatment with type II collagen alone. In contrast, anti-TCR gamma delta mAb injection of arthritic mice 40 days after collagen injection resulted in the rapid onset of severe arthritis which was accompanied by increased bone erosion and cell infiltration into inflamed joints compared with arthritic mice injected with either control hamster IgG or F(ab')2 fragments of 13D5. Arthritic mice injected with intact 13D5 rapidly lost weight, suggesting that 13D5 may induce a cytokine-mediated syndrome similar to that observed in mice and humans after the injection of anti-CD3. Flow cytometry analysis of joint cells isolated after collagenase digestion from arthritic mice demonstrated that 13D5 injection induces the accumulation of CD4-, CD8-, PgP-1 (CD44)+ cells within arthritic joints, whereas arthritic joints from mice injected with control hamster IgG contained cells with a CD4+, CD8- phenotype. CD3+ T cell lines which express the gamma delta TCR from inflamed joints of arthritic mice were established and examined for V gamma usage by the polymerase chain reaction. V gamma 2 rearrangements were predominant in both T cell lines established from inflamed synovium as well as freshly isolated synovial cells from arthritic mice, whereas synovial cells from nonarthritic mice did not demonstrate V gamma 2 rearrangements. Taken together, the results described in this report suggest a direct role for gamma delta TCR T cells in the pathogenesis of CIA in DBA/1 lac J mice.

Ibopamine. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic use in congestive heart failure

Ibopamine is an orally administered dopamine agonist which is rapidly converted to its active metabolite epinine by esterase hydrolysis. Ibopamine acts predominantly as a vasodilator and inhibitor of neuroendocrine activation in congestive heart failure, but also has mild positive inotropic effects at higher doses. The beneficial effects on cardiac and systemic haemodynamic parameters seen in short term studies have been maintained in predominantly noncomparative trials for up to 1 year, and improvements in New York Heart Association (NYHA) functional class and clinical symptoms have been observed in patients with congestive heart failure of varying severity. In double-blind studies conducted in small numbers of patients, the efficacy of ibopamine was comparable to that of digoxin, captopril, enalapril and hydrochlorothiazide. Ibopamine can successfully replace treatment with intravenous dopamine in patients with severe heart failure, and is effective and well tolerated when administered in combination with digoxin, diuretics and/or angiotensin converting enzyme (ACE) inhibitors. Ibopamine has shown no detrimental effects on renal function, few adverse effects on neurohormonal parameters and has demonstrated no significant proarrhythmic properties at therapeutic doses in patients with congestive heart failure. No adverse metabolic effects were observed during ibopamine therapy in patients with diabetes mellitus, nor did ibopamine have detrimental effects in patients with chronic obstructive pulmonary disease. While reliable evidence is required concerning effects on mortality before the role of ibopamine can be clearly defined, the drug appears to be a useful agent for combination with conventional therapies in treating patients with mild to severe congestive heart failure.

Are you ready for a CLIA inspection?

Despite talk within the Clinton administration of watering down the Clinical Laboratory Improvement Amendments (CLIA) of 1988, currently CLIA is the law of the land. Federal officials say that physicians shouldn't expect any significant changes in the law until 1995 at the earliest. Already, surveyors have begun inspecting physician office laboratories across the country. This article, written by staff from ASIM's Medical Laboratory Evaluation (MLE) program, explains how to prepare your lab for inspection. The article originally appeared in "Focus On ... Physician Office Laboratories," a newsletter for MLE participants. More information on MLE is available by calling (202) 835-2746, ext. 274.

The lack of long-term detrimental effects on liver allografts caused by donor-specific anti-HLA antibodies

Recent reports indicate a higher incidence of both acute and chronic liver allograft rejection when, at the time of transplantation, the recipients serum contains donor-specific anti-HLA antibodies. From 9/89 to 5/91, 133 liver allografts were performed at our institution. Thirteen liver recipients had donor-specific IgG anti-HLA antibodies (complement-fixing) at the time of transplantation. In eleven patients, antibodies reacted to donor class I antigens while in 1 patient the donor-specific antibody had class II reactivity. Twelve patients have been followed for a minimum of 12 months (median 18 months, range 28-12 months). No hyperacute rejection was seen in any of the cases and four patients had acute rejections. Thus far only one of the twelve patients has biopsy evidence suggestive of chronic liver injury. The remaining have normal liver enzymes and bilirubin. Three of these twelve patients died (one from a myocardial infarction and the others from sepsis) accounting for a one-year graft survival of 75%. There was no significant statistical difference in the one-year graft survival in those recipients without donor-specific antibodies (i.e., 80.5%). In eight of the twelve patients, pretransplant preformed antibody level (PRA) was > 50%. In six of the thirteen patients donor-specific antibody was present at dilutions greater than 1:64. As previously reported, the donor-specific antibody disappeared from the serum posttransplant within hours and did not reappear. In vitro studies demonstrated no factor in portal or hepatic artery blood that could inhibit rabbit complement mediated lysis of anti-HLA antibodies. We conclude that it is not a contraindication to do liver transplants in the presence of donor-specific anti-HLA antibodies.

mRNA structure, in situ, as assessed by microscopic techniques

The secondary and tertiary structure of RNA, in situ, is thought to be involved in distinct functions such as directing association of the RNA with the cytoskeleton, enzymatic activity of some RNAs, and the control of translation. In situ transcription (IST), a procedure by which cDNA is synthesized in situ, has been used to assess mRNA structure in situ using fixed cells or tissues. Distinct banding patterns were noted for mouse and rat POMC. Unique IST banding patterns were observed when an oligonucleotide complementary to a putative POMC stem-loop structure was used to prime IST. Indeed local changes in banding patterns could be elicited by pharmacological agents which modulate POMC translation. Inhibition of POMC synthesis with NaF or dexamethasone decreased the number of POMC mRNAs in the polysome fractions and increased the intensity of high molecular weight IST-derived bands. Forskolin, a stimulator of POMC synthesis, had the opposite effect. One mechanism by which translational control is thought to occur is by regulation of ribosome movement down the mRNA by specific binding of cytosolic proteins to RNA structure. Cytosolic protein fractions from AtT20 pituitary cells have been shown to specifically bind to the IST-predicted RNA structure. These findings suggest that 1) mRNA structure can be assessed in situ, 2) translation may be altered by the secondary and tertiary structure of mRNAs, and 3) a predicted stem-loop structure exists in situ in the 5'-end of POMC mRNA.

Sequences in the human c-myc P2 promoter affect the elongation and premature termination of transcripts initiated from the upstream P1 promoter

A conditional block to transcription elongation provides one mechanism for controlling the steady-state levels of c-myc RNA in mammalian cells. Although prematurely terminated c-myc RNAs are not detectable in mammalian cells, truncated c-myc RNAs with 3' ends that map near the end of the first exon are transcribed from human c-myc templates injected into Xenopus oocytes germinal vesicles. A series of linker scanner and deletion mutants within the c-myc P2 promoter was tested in the Xenopus oocyte injection assay to determine the potential contribution of promoter elements to the elongation or premature termination of c-myc transcription. Although this analysis failed to identify sequences in the P2 promoter that significantly affect the elongation or termination of P2-initiated transcripts, our results suggest that sequences within the P2 promoter contribute to the premature termination of transcripts initiated at the upstream P1 promoter. A subset of these sequences is essential for the efficient elongation of P1-initiated transcripts through intrinsic sites of termination at the end of exon 1. These sequences affect P1 elongation when they are downstream of the site of initiation, and we hypothesize that they may be analogous to a class of prokaryotic elements required for antitermination.

The T cell receptor in autoimmune diseases

Autoimmunity is likely the cause of a variety of diseases including systemic lupus erythematosus, rheumatoid arthritis and diabetes. Normally, the body's immune system serves as a defense against a variety of conditions, including, injury, infection and neoplasm. However, for reasons that are currently unclear, the normal regulation of the immune system can breakdown resulting in autoaggressive responses. T cells, especially CD4+ cells, appear to play a predominant role in most autoimmune diseases. We summarize our workshop which focussed on the role of the T cells in autoimmune diseases. We summarize our workshop which focussed on the role of the T cells in autoimmune diseases; the T cell receptor in autoantigen recognition (emphasizing the role of selective T cell receptor V regions in the autoimmune response); and a discussion of possible therapeutic interventions.

Complementary DNA synthesis in situ: methods and applications

In situ transcription is the synthesis of cDNA within cells. This chapter has illustrated some of the application of IST to the study of gene expression in complex cell environments. While the importance of transcription in modulating cellular activity has been long appreciated, the role of translational control mechanisms in regulating central nervous system functioning is just beginning to be recognized. Previous limitations in the availability of tissue have made it difficult to construct cDNA libraries from defined cell populations, to examine translational control, and to quantitate differences in the amount of mRNA for many distinct mRNAs in the same sample. In situ transcription facilitates all of these procedures, making it possible to characterize aspects of gene regulation that were previously difficult. Indeed, taken to its furthest extreme it is now possible to characterize gene expression in single live cells. This level of analysis allows basic questions, such as How different morphologically identical cells are at the level of gene expression, and How synaptic connectivity and glial interactions influence gene expression in single cells, to be experimentally approached. The ability to characterize gene expression in small amounts of tissue and single cells is critical to gaining an understanding of the contribution of specific cell types to the physiology of the central nervous system.

An improved method for the preparation of M13 plaques for amplification by the polymerase chain reaction

Images

Stargazer: a new neurological mutant on chromosome 15 in the mouse with prolonged cortical seizures

We report here the initial description of the inheritance pattern, linkage mapping, and electroclinical phenotype of a recessive mutation on mouse Chromosome 15, stargazer (stg), that produces epilepsy. The salient epileptic phenotype is a syndrome of spontaneous, prolonged, generalized spike-wave cortical discharges with behavioral arrest. A second, complex, seizure pattern featuring movements during the discharge can also appear. The stg/stg mutant phenotype confirms the general principal that inherited epilepsies sharing similar cortical excitability patterns can be transmitted by single gene loci residing on different chromosomes and provides new evidence that the severity of seizure expression depends on the specific mutant gene affected.

The development of 3- to 6-year-olds' map using ability: the relative importance of landmarks and map alignment

Previous research (e.g., Bluestein & Acredolo, 1979) has demonstrated that children as young as 3 or 4 years of age can use simple maps, if the maps are aligned, and has suggested that when such young children use a map, they rely on the information provided about landmarks. The support for this suggestion, however, comes from research with older children. Our experiment was designed to find out how 3- to 6-year-olds used a map and whether they could use maps that were not aligned. The children were asked to find a hidden toy in a mapped layout that showed the toy's position and included a single landmark. The maps were either aligned or rotated 90 degrees, 180 degrees, or 270 degrees relative to the layout. The results showed that young children could use the maps, even when they were not aligned with the layout, and that they relied on landmark information to do so.

Drugs and Iran after the Islamic revolution: prophesying the next quarter century

Prior to the Islamic revolution of 1979, research on Iran's long-standing drug use patterns had begun in clinic settings, but there were few data available on countrywide use. Opium, the traditional drug used in social settings and produced in quantity in the east of the country, was the first target of fierce antidrug measures in 1979. The course of future drug cultivation, use, treatment and, therefore, research needed on the drug problem is closely linked to political developments in Iran. Much will depend on whether Iran maintains an independent stance or rejoins the international agencies' efforts.

Immobilization of polar bears (Ursus maritimus) with Telazol in the Canadian Arctic

In 1986, 213 polar bears (Ursus maritimus) were immobilized with Telazol on the sea ice of the eastern Beaufort Sea during April and May, and 106 along the western coast of Hudson Bay near Churchill, Manitoba (Canada) in September. No animals died from handling. The efficacy of this drug at different seasons and the physiological responses of the immobilized bears were compared. A single injection of 8 to 9 mg of Telazol per kg of body weight gave a rapid full immobilization with satisfactory analgesia, and faster recovery than other drugs for which there is no antagonist. The reactions of the bears could be reliably and easily interpreted from a safe distance before the animal was approached. There was a wide range of tolerance to high dosages and bears appeared able to thermoregulate while immobilized. The mortality rate due to handling was lower than with any other drug used to date.

Measurement and analysis of intraservice work

The work that physicians perform represents a major resource input to medical services and procedures. In this article we describe the concepts of work and its dimensions, as well as the methods developed to measure them. We also describe the design and results of a national probability survey of physicians in 18 specialties. We present the results--estimated values of work and its dimensions--for selected services. Our findings indicate that physicians can give reliable and valid ratings of work and that we can model this work as a function of four dimensions: time, mental effort and judgment, technical skill and physical effort, and stress. Analyzing the complex functional relationship between work and these four dimensions shows that all four dimensions are important and statistically significant in predicting work. Time is a more important dimension in predicting work for medical specialties than for surgical specialties, with the estimated regression coefficients between .3 and .5 and .2 and .3, respectively. In contrast, technical skill is a more important dimension in predicting work in surgical specialties than for medical specialties, with the estimated regression coefficients between .3 and .5 and .2 and .3, respectively. Finally, we found that an exponential equation of the four dimensions precisely describes total work.

The relation of thyroid indices in the critically ill patient to prognosis and nutritional factors

Thyroid indices and nutritional assessment values were measured in 73 critically ill euthyroid patients within 48 hours of admission to the medical or surgical intensive care unit. Significantly increased rates of mortality were observed among patients with decreased T3 or T4 levels or elevated T3UR or rT3 values. Alterations in thyroid function tests were associated with changes in certain putative nutritional indices, including serum albumin and transferrin concentrations, triceps skin fold and skin test reactivity. The data indicated that thyroid parameters measured early in the critical phase of illness are predictive of subsequent outcome. The pathogenesis of altered thyroid hormone metabolism is unknown, but nutritional deprivation may be an important contributing factor.

Specificity of sensitive assays of thyrotropin (TSH) used to screen for thyroid disease in hospitalized patients

Thyrotropin (TSH) concentrations were measured in 1580 hospitalized patients and 109 normal persons. Using the mean +/- 3 SD limits of the log values for the controls (0.35-6.7 milli-int. units/L), the proportion of abnormal TSH results in the hospitalized patients was 17.2%. TSH was undetectable (less than 0.1 milli-int. unit/L) in 3.1% of patients, suggesting hyperthyroidism, and high (greater than 20 milli-int. units/L) in 1.6%, suggesting hypothyroidism. On follow-up of 329 patients, 62% with abnormal TSH (less than 0.35 or greater than 6.7 milli-int. units/L) and 38% with normal TSH concentrations, only 24% of those with undetectable TSH had thyroid disease: 36% of them were being treated with glucocorticoids and 40% had nonthyroidal illness (NTI). Although half the patients with TSH greater than 20 milli-int. units/L had thyroid disease, 45% of patients had high TSH values associated with NTI. TSH concentrations usually returned towards normal when patients' therapy with glucocorticoids was discontinued or they recovered from NTI. TSH test sensitivity appeared good when the mean +/- 3 SD limits of the reference population were used, i.e., no cases of hyper- or hypothyroidism, as identified by free thyroxin index (FT4I), were missed. However, TSH test specificity was inferior to that of the FT4I test (90.7% vs 92.3%), although specificity could be improved to 97.0% if the wider TSH reference limits of 0.1 to 20 milli-int. units/L were used--limits considered pathological if applied to outpatients. Evidently, different reference intervals for TSH are needed for hospitalized and nonhospitalized patients. We conclude that a "sensitive TSH assay" is not a cost-effective thyroid screening test for hospitalized patients as compared with the FT4I.

Specificity of sensitive assays of thyrotropin (TSH) used to screen for thyroid disease in hospitalized patients

Thyrotropin (TSH) concentrations were measured in 1580 hospitalized patients and 109 normal persons. Using the mean +/- 3 SD limits of the log values for the controls (0.35-6.7 milli-int. units/L), the proportion of abnormal TSH results in the hospitalized patients was 17.2%. TSH was undetectable (less than 0.1 milli-int. unit/L) in 3.1% of patients, suggesting hyperthyroidism, and high (greater than 20 milli-int. units/L) in 1.6%, suggesting hypothyroidism. On follow-up of 329 patients, 62% with abnormal TSH (less than 0.35 or greater than 6.7 milli-int. units/L) and 38% with normal TSH concentrations, only 24% of those with undetectable TSH had thyroid disease: 36% of them were being treated with glucocorticoids and 40% had nonthyroidal illness (NTI). Although half the patients with TSH greater than 20 milli-int. units/L had thyroid disease, 45% of patients had high TSH values associated with NTI. TSH concentrations usually returned towards normal when patients' therapy with glucocorticoids was discontinued or they recovered from NTI. TSH test sensitivity appeared good when the mean +/- 3 SD limits of the reference population were used, i.e., no cases of hyper- or hypothyroidism, as identified by free thyroxin index (FT4I), were missed. However, TSH test specificity was inferior to that of the FT4I test (90.7% vs 92.3%), although specificity could be improved to 97.0% if the wider TSH reference limits of 0.1 to 20 milli-int. units/L were used--limits considered pathological if applied to outpatients. Evidently, different reference intervals for TSH are needed for hospitalized and nonhospitalized patients. We conclude that a "sensitive TSH assay" is not a cost-effective thyroid screening test for hospitalized patients as compared with the FT4I.

Time course and frequency dependence of synaptic vesicle depletion and recovery in electrically stimulated sympathetic ganglia

The mammalian superior cervical sympathetic ganglion has been extensively used to study the kinetics of ACh metabolism and release. The present investigation examined the time course of changes in the number of synaptic vesicles and abundance of plasma membrane at preganglionic nerve terminals using stimulation protocols similar to those used in previous biochemical and electrophysiological studies. Continuous stimulation of the preganglionic trunk to the cat superior cervical ganglion in vivo produced an initially rapid fall in the number of clear synaptic vesicles followed by a subsequent plateau. Reciprocal changes in plasma membrane occurred with a similar time course. The plateau phase is interpreted as a steady-state where vesicle exocytosis is balanced by the rate of vesicle reformation from plasma membrane. During quiescent recovery, restoration of normal resting ultrastructure is initially rapid but slows with time as vesicle number and plasma membrane abundance approach pre-stimulation values, indicating that the rate of vesicle reformation at the end of stimulation is high and proportional to the number of vesicles incorporated into the plasma membrane. These results are interpreted as consistent with the 'vesicle hypothesis' of neurotransmitter release.

The relationship between phosphate status and photosynthesis in leaves : Effects on intracellular orthophosphate distribution, photosynthesis and assimilate partitioning

Photosynthesis, assimilate partitioning and intracellular distribution of orthophosphate (Pi) in barly (Hordeum vulgare L.) leaves were measured in plants grown with either 25, 1 or 0 mmol· 1(-1) nutrient phosphate supply. Phosphate deficiency resulted in a significant decrease in the leaf Pi, diminished rates of photosynthesis and a decrease in the sucrose/starch ratio in the leaves. Changes in the cytoplasmic Pi content were relatively small in comparison with the large variations in vacuolar Pi. The cytoplasmic Pi concentration was slightly higher in the leaves of plants grown at 25 mmol·l(-1) Pi than in those grown at 1 mmol·l(-1) Pi and was decreased in the phosphate-deficient plants in which photosynthesis was inhibited. With barley plants grown in phosphate-deficient media, very little, if any, Pi was present in the vacuole. All of the cellular Pi was in the cytoplasm. Barley, spinach (Spinacia oleracea L.) and soya (Glycine max L.) plants were grown to a comparative stage of phosphate deficiency as measured by leaf Pi levels. These species showed a uniform response to phosphate deficiency by increasing starch synthesis relative to sucrose but the accompanying limitation on photosynthetic capacity varied considerably among the species. Interspecific differences in assimilate partitioning between starch and sucrose were maintained over a wide range of Pi supply.

Treatment of degenerative spondylolisthesis

The purpose of this article is to evaluate three surgical approaches to the treatment of degenerative spondylolisthesis. A review of 107 surgically treated cases were used to select a group of patients who met the following criteria: No previous spine surgery, no involvement in litigation, and no significant lesions at other levels of the spine. Adequate follow-up. The selected group of 47 surgically treated cases of degenerative spondylolisthesis had follow-up of 2-7 years. Three surgical approaches to the treatment of degenerative spondylolisthesis were analyzed. A relatively small patient group with a wide posterior decompression, at the level of the slip, sacrificing the articular processes had good to excellent results in only 33% of the cases. A second group with a midline posterior decompression with preservation of the articular processes had 80% good to excellent results after 2 years. The third group with a midline decompression and preservation of the articular processes had an added intertransverse process fusion between the olisthetic levels. This group had 90% good to excellent results. The conclusion is that a posterior decompression with preservation of the articular processes plus a transverse process fusion at the involved level is the preferred method of treatment for degenerative spondylolisthesis without regard to age.

A comparative study of metabolite levels in plant leaf material in the dark

Metabolite levels have been compared in the dark and during photosynthesis in leaves and protoplasts from spinach, pea, wheat and barley. In protoplasts the subcellular distribution was also studied. The levels of triose phosphates and sugar bisphosphates were high in the light and low in the dark. The hexose phosphates and 3-phosphoglycerate levels in the dark were very variable depending on the plant material. In most conditions, hexose phosphates and triose phosphates were mainly in the extrachloroplast compartment, while 3-phosphoglycerate and the sugar bisphosphates were mainly in the chloroplast compartment. Leaves always had a very low triose phosphate: 3-phosphoglycerate ratio in the dark, but in protoplasts this ratio was higher. Detailed studies with spinach showed that metabolite levels were very dependent on the availability of carbohydrate in the leaf, particularly starch. Starch mobilisation is not controlled just by the availability of inorganic phosphate and accumulation of phosphorylated intermediates. Hydrolysis of starch may provide precursors for sucrose synthesis while phosphorolysis leads to provision of substrates for respiration. Starch breakdown generates high enough levels of hexose phosphate to support substantial rates of sucrose synthesis in the dark. Respiration is not greatly increased when metabolite levels are high during starch mobilisation. Higher levels of metabolites shorten the length of the induction phase of photosynthesis.

Drug addicts seeking treatment after the Iranian Revolution: a clinic-based study

A sample survey of 200 addicts attending the Rehabilitation Centre at Shiraz was conducted after the 1979 Iranian Revolution had disrupted both drug supply and addict treatment programmes. The study showed that clinics were, after the revolution, seeing a broader social range of addicts than before; and that action by the authorities was bringing many recently-addicted individuals to clinics. Heroin use predominated among those who were urban residents, whilst villagers were more likely to be opium users. The survey also sought the addicts' perceptions of the reasons for their initiation and addiction.

Exploring the use and non-use of marijuana as reasoned actions: an application of Fishbein and Ajzen's methodology

Fishbein and Ajzen's methodology can predict behaviour on the basis of questionnaire measures of attitudes toward the specific act and the subjective norms with respect to that behaviour which the individual experiences. In the present study this methodology was used to differentiate between the non-users, experimenters, occasional users and regular users of marijuana in a student population. It is argued that Fishbein's approach enables each of these groups' behaviour to be seen as a reasoned action; also discriminant analysis shows how particular evaluative beliefs and social norms interact to predict and explain the individual's drug-user status.

Transient effect of L-5-hydroxytryptophan on pituitary function in men and women

To further elucidate the role of serotonin in the secretion of pituitary hormones, a loading dose of 0.8 mg/kg for 1 h, following by a maintenance dose of 0.1 mg/kg . h of L-5-hydroxytryptophan (5-HTP) for 23 h were administered iv to five normal men and five normal women. Five additional men received repeated loading doses of 5-HTP 4 and 6 h after the initial one, with or without the maintenance dose. The initial studies demonstrated a significant, but transient, increase in plasma PRL, GH, cortisol (P less than 0.01) and TSH (P less than 0.05) in the five man and a consistent and significant transient increase only in PRL and cortisol in the five women. Plasma LH and FSH values were not affected by 5-HTP administration. The constant administration of 5-HTP revealed a blunting effect on the nocturnal rise of TSH in men. The continuous administration of 5 HTP failed to maintain the rise induced by the loading dose. Individuals receiving additional loading doses of 5-HTP demonstrated a subsequent increase in GH and cortisol, but not in serum PRL. This study suggests that endogenous serotonin may exert its stimulatory effect on pituitary hormone secretion primarily by sporadic release, rather than by continuous secretion.

Beliefs and opinions about drugs and their users as predictors of drug-user status of adolescents in post-revolutionary Iran

In a sample survey of 712 Iranian male adolescents, aged 14-18, it was found that drugs users differed in only some of theirs beliefs about drug substances and their use from their non-drug-using contemporaries; and that both sub-samples had, in their agreement about the drug problem in post-revolutionary Iran, been equally influenced by the information presented in the media. Similarly, there was general agreement about the characteristics of regular drug users. The major factor predictive of drug-user status in this sample was the extent of the individual's exposure to models of drug use; such models being more likely to be adult family members than the adolescent's age-peers, a reversal of the situation usually found in Europe and America.

Social background, personal relationships, and self-descriptions as predictors of drug-user status: a study of adolescents in post-revolutionary Iran

Iranian adolescents who have ever used drugs exhibit significant differences from their non-using peers in terms of their lowered educational aspirations, reported health and sense of well-being; and they would be more likely to rely upon friends' rather than parents' support if in serious trouble. But, unlike many studies of European, American and South-East Asian adolescents, the present sample of drug users show few other signs of rebelliousness or alienation: they report themselves as religious as the non-users, and their school performance is little depressed. The drug user sub-sample contains a disproportionately high number of children from both the richest and the poorest families in society.

Patterns of drug use among secondary school children in post-revolutionary Iran

A sample survey of 712 Iranian youths aged 14 - 18 years, attending secondary schools in the city of Isfahan, indicated that 11% had had experience of drug abuse. The most common pattern was the experimental use of opium, with a minority of users having also used hashish or heroin. No other drugs were reported, but a significant association between the use of opium and of cigarettes and, to a lesser extent, alcohol was observed. However, given a relatively early peak in initiation to opium smoking, it seems that the initiation to the use of cigarettes and alcohol is contemporary with, rather than preceding the initiation to opium. Drug migration patterns described in Western samples and in some areas of South East Asia are not applicable to more traditional societies.

Cardiovascular effects of phenelzine and amitriptyline in depressed outpatients

Blood pressure and ECG changes were monitored in depressed outpatients treated for 6 weeks with amitriptyline, 150 mg/day, or phenelzine, 60 mg/day, as part of an ongoing double-blind study. Phenelzine produced significant decreases in blood pressure and a significant increase in orthostatic fall in pressure. Amitriptyline produced little overall change in blood pressure. The degree of MAO inhibition in phenelzine-treated patients was significantly correlated with blood pressure. Tricyclic plasma concentrations were also related to some blood pressure measures. Reported dizziness/faintness did not correlate with blood pressure changes in either group. Amitriptyline significantly increased heart rate, while phenelzine produced slowing. Amitriptyline was associated with significant prolongation of QRS and QTc but not PR intervals. Phenelzine produced significant shortening of the QTc interval.

Observations on the phosphate status and intracellular pH of intact cells, protoplasts and chloroplasts from photosynthetic tissue using phosphorus-31 nuclear magnetic resonance

Individual pools of intracellular inorganic phosphate (Pi) can be observed in the dark in intact cells, protoplasts and chloroplasts from photosynthetic tissue by using 31P nuclear magnetic resonance (n.m.r.). Estimates for the pH of vacuolar and extravacuolar compartments are reported although it is shown that intracellular pH is determined by the pH of the suspending medium. Mannose treatment of asparagus (Asparagus officinalis) cells and spinach (Spinacia oleracea) protoplasts results in the inhibition of photosynthesis. The mechanism of mannose phosphate sequestration of free Pi is supported by the 31P n.m.r. spectra of mannose-treated tissue. There is a fundamental difference in 31 P n.m.r. spectra of mannose-treated spinach protoplasts and asparagus cells, reflecting a difference in the availability of vacuolar Pi for cellular metabolism in these species. The 31P n.m.r. spectrum of intact spinach chloroplasts is reported.

Critical appraisal of complement dependent microlymphocytotoxicity assay for detecting donor-specific alloantibody pretransplant--importance of indirect immunofluorescence as a superior alternative

The ability of complement-dependent microlymphocytotoxicity assay (CdL) to detect and discriminate between the various types of donor-specific alloantibodies was reevaluated. Data obtained with the CdL assay on purified B and T lymphocytes at warm and cold temperatures was compared to other modes of antibody-detection, i.e., indirect immunofluorescence (IF) and the noncomplement-dependent antibody-dependent cellular cytotoxicity (ADCC). Additionally, the significance of antibodies as detected by CdL and IF was ascertained by correlating with kidney transplant outcome. It became apparent that the CdL assay identified weakly reactive HLA-ABC alloantibodies as being B cell specific. Such weakly reactive HLA-ABC antibodies were also not appreciated in the presence of the cold reactive IgM antibody. Accelerated rejections were the rule in the presence of weakly reactive HLA-ABC alloantibodies indicating that their detection was highly important. The IF assay could discriminate between the antibody class, could detect weakly reactive HLA-ABC alloantibodies, and could detect noncomplement fixing antibodies (ADCC). Further, use of IF prevented us from unnecessarily denying transplants to certain recipients when a positive CdL assay resulted from an IgM antibody or poor cell viability.

Legal sanctions and information about drugs as influences upon the decision by adolescents whether to use illicit drugs

Although those Malaysian secondary schoolchildren who have never used drugs are consistent in their support for legal and social sanctions against drug use, it is argued that such sanctions are a relatively unimportant factor in the decision whether or not to use drugs. Non-drug users inhabit a social world separated from their drug-using contemporaries; they rely on information from public rather than direct social sources, and claim to have been little interested in information received. However, there is evidence that, for a minority of the drug-using sub-sample, public information campaigns have made them more rather than less interested in experimenting with drug substances.

Social attitudes, self-description and perceived reasons for using drugs: a survey of the secondary school population in Malaysia

The present paper is the third and concluding part of a study of the secondary school population of two of Malaysia's thirteen states, Penang and Selangor. Since completion of the two earlier papers, the research team has investigated the pattern and nature of drug use among the equivalent population in a third state, Kelantan, and has again found essentially the same pattern of results: youthful drug use is most clearly related to precocious self-assertion, and a set of beliefs and attitudes about drugs and drug taking, and is largely unrelated to indicators of social deprivation or personal problems. The significance of this repeated finding in Kelantan is that, in this much more rural and traditional state, adult and established patterns of drug use had historically differed considerably from those found in the two more urban and cosmopolitan states of Penang and Selangor. Our findings indicate that the new pattern of drug use by youth has transcended the older cultural differences between the states, and is in turn explained by a more universally familiar set of characteristics in adolescent development.

Social background and attitudes towards drugs as predictors of drug use among Malaysian students

Those Malaysian secondary schoolchildren who have ever used an illicit drug do not differ significantly in terms of social class background, ethnicity or rural/urban location, from the majority of their contemporaries who have not used drugs. The cross-sectional data show a rapid secular trend towards the sexes being equally involved in drug use. Significant differences between ever and never users are, however, found in their attitudes towards drug taking and their beliefs about the properties of drugs, although both groups share the same rather negative image of the typical drug user. Thus, drug users have accepted some of the attitudes towards drug issues which are normative in the non-user group, whilst developing other attitudes which are consistent with their continuing use. It is argued that adolescent drug abuse in Malaysia is not to be linked specifically with social deprivation, but should be seen as being part of the life style of particular groups in all strata of society.