Multifunctionality and diversity within the plant MYB-gene family

MYB proteins constitute a diverse class of DNA-binding proteins of particular importance in transcriptional regulation in plants. Members are characterised by having a structurally conserved DNA-binding domain, the MYB domain. Different categories of MYB proteins can be identified depending on the number of imperfect repeats of the MYB domain they contain. It is likely that single MYB-domain proteins, a class of expanding importance in plants, bind DNA in a different way than two-repeat or three-repeat MYB proteins, and these groups are therefore likely to have different functions. The two-repeat (R2R3) MYB family is the largest family characterised in plants, and there are estimated to be over 100 members in Arabidopsis. Functions of MYB proteins in plants include regulation of secondary metabolism, control of cellular morphogenesis and regulation of meristem formation and the cell cycle. Although functional similarities exist between R2R3 MYB proteins that are closely related structurally, there are significant differences in the ways very similar proteins function in different species and also within the same organism. Therefore, despite the large number of R2R3 MYB proteins in plants, it is unlikely that many are precisely redundant in their functions, but more likely that they share overlapping functions.

Strength of discourse context as a determinant of the subordinate bias effect

Two experiments examined the influence of strength of discourse bias on lexical ambiguity resolution. Short passages were constructed to bias polarized ambiguous words (homonymous) strongly or weakly toward the dominant or subordinate meanings. Using a self-paced reading task in Experiment 1, it was demonstrated that in strongly biased discourse, reading times for homonyms in dominant discourse did not differ from those in subordinate discourse. However, when the discourse was weakly biased, homonyms were read faster in dominant discourse than in subordinate discourse. Experiment 2 combined the reading paradigm with a naming task in order to provide an assessment of specific word-meaning activation. Reading times on ambiguous words replicated the results of Experiment 1. In addition, naming latencies for probe words revealed that only the contextually appropriate sense of a homonym was activated in strongly biased discourse. In contrast, both contextually appropriate and inappropriate senses were activated following a weakly biased subordinate discourse, whereas only the dominant sense was activated following weakly biased dominant discourse. The results demonstrate (1) an immediate influence of prior discourse information on lexical processing; and (2) that the strength of discourse constraints can play a governing role in lexical ambiguity resolution. The results were interpreted within the framework of a context-sensitive model of lexical ambiguity resolution.

Passive expiratory flow-volume curve is not an accurate method to measure the respiratory time constant in rabbits

BACKGROUND

In mechanically ventilated patients, inspiration is forced by an externally applied positive pressure whereas expiration remains passive and depends on the time constant of the total respiratory system (tau), which constitutes an important determinant of mechanical ventilation. The end-inspiratory occlusion technique is one of the easiest methods to obtain tau values in ventilated patients, especially infants, but its accuracy is not well established. The aim of this study was to compare in anesthetized, paralyzed rabbits tau values given by the end-inspiratory occlusion technique (tau(rs)) to tau values obtained by references methods for measurements (i.e. the product of static lung compliance by airway resistance: tau(ref)) during carbachol-induced bronchospasm eliciting marked modifications of the respiratory mechanics.

METHODS

Comparisons were made in the basal state and after carbachol-induced bronchoconstriction in seven New Zealand adult rabbits. This procedure resulted in a wide range of expiratory time constants. A pneumotachograph was used to measure expiratory flow and volume before and after end-inspiratory occlusion. The slope of the flow volume curve gave tau(rs). Then tau(rs) was compared with tau(ref) (which ranged from 0.30 to 1.96 s).

RESULTS

Statistical analysis revealed a weak correlation between the two methods, and a size-dependent bias of tau(rs) measurements.

CONCLUSIONS

The end-inspiratory occlusion technique leads to a systemic bias in measurements of respiratory time constant, especially when the resistance of the respiratory system is elevated.

NOS2-derived nitric oxide regulates the size, quantity and quality of granuloma formation in Mycobacterium avium-infected mice without affecting bacterial loads

Granuloma formation in response to mycobacterial infections is associated with increased expression of inducible nitric oxide synthase (NOS2) within granuloma macrophages and increased levels of nitrate/nitrite in the sera of infected mice. Continuous treatment with 5 mm or 10 mm l-N6-(1-imino-ethyl)-lysine (L-NIL), a selective NOS2-inhibitor, in acidified drinking water for up to 7 weeks consistently reduced infection-induced nitrate/nitrite to background levels in mycobacteria-infected BALB/c mice. Oral treatment with 5 mm L-NIL initiated at the time of infection significantly exacerbated growth of Mycobacterium tuberculosis, but had no effect on Mycobacterium avium colony-forming unit development in the liver, spleen and lungs of intravenously infected mice. In order to examine the role of nitric oxide in mycobacteria-induced granulomatous inflammation in the absence of any effect on the bacterial load, M. avium-infected mice were treated with 5 mm L-NIL from day 1 through 38 and the development of granulomatous lesions in the liver was assessed by histology, immunohistology and reverse-transcription-polymerase chain reaction (RT-PCR). Computer- and video-assisted morphometry performed at 4 and 7 weeks post-infection showed that treatment with L-NIL led to markedly increased number, cellularity and size of granulomatous lesions in infected mice regardless of the virulence of the M. avium isolate used for infection. Immunohistology of the liver revealed that in mice treated with L-NIL, the numbers of CD3+ T cells, CD21/35+ B cells, CD11b+ macrophages and RB6-8C5+ granulocytes associated with granulomatous lesions was increased. RT-PCR of the liver showed that in L-NIL-treated mice infected with M. avium, mRNA levels of tumour necrosis factor, interleukin-12p40, interferon-gamma, interleukin-10 and interferon-gamma-inducible protein-10 (IP-10) were up-regulated, while mRNA levels of interleukin-4, monocyte chemotactic protein-1 (MCP-1) and MCP-5 were similar to those in untreated control infected mice. When M. avium-infected mice were treated with 5 mm L-NIL between the 5th and 12th weeks of infection, similar changes in granuloma number and size were found in the absence of any effect on the bacterial load. These findings demonstrate that nitric oxide regulates the number, size and cellular composition of M. avium-induced granulomas independently of antibacterial effects by modulating the cytokine profile within infected tissues.

Characterization of a periplasmic ATP-binding cassette iron import system of Brachyspira (Serpulina) hyodysenteriae

The nucleotide sequence of the pathogenic spirochete Brachyspira hyodysenteriae bit (for "Brachyspira iron transport") genomic region has been determined. The bit region is likely to encode an iron ATP-binding cassette transport system with some homology to those encountered in gram-negative bacteria. Six open reading frames oriented in the same direction and physically linked have been identified. This system possesses a protein containing ATP-binding motifs (BitD), two hydrophobic cytoplasmic membrane permeases (BitE and BitF), and at least three lipoproteins (BitA, BitB, and BitC) with homology to iron periplasmic binding proteins. These periplasmic binding proteins exhibit lipoprotein features. They are labeled by [(3)H]palmitate when tested in recombinant Escherichia coli, and their signal peptides are typical for substrates of the type II secretory peptidase. The FURTA system and Congo red assay indicate that BitB and BitC are involved in iron binding. The Bit system is detected only in B. hyodysenteriae and is absent from B. innocens and B. pilosicoli.

Primary association of a TNF gene polymorphism with susceptibility to multiple sclerosis

The associations of three promoter polymorphisms in the tumor necrosis factor (TNFA) gene have been studied in 238 patients and 324 control subjects. A significant correlation was found between MS susceptibility and the TNFA-376 polymorphism. This association was independent of the human leukocyte antigen (HLA) class II association and the combined inheritance of HLA-DRB1*1501 and the TNFA-376A allele more than additively increased susceptibility to MS.

Posttraumatic subgaleal hematoma: a case report and review of the literature

INTRODUCTION

A subgaleal hematoma or subaponeurotic hemorrhage occurs infrequently and is usually seen in pediatric patients, especially in the neonatal period. It may be associated with coagulation disorders.

CASE REPORT

We report on a previously healthy 19-month-old patient who presented with an extensive subgaleal hematoma and significant anemia secondary to a fall.

DISCUSSION

A literature review was conducted, and the etiology, diagnosis, and treatment of the subgaleal hematoma are discussed.

CONCLUSION

Conservative treatment, except in select severe cases, is recommended for this condition.

Function search in a large transcription factor gene family in Arabidopsis: assessing the potential of reverse genetics to identify insertional mutations in R2R3 MYB genes

More than 92 genes encoding MYB transcription factors of the R2R3 class have been described in Arabidopsis. The functions of a few members of this large gene family have been described, indicating important roles for R2R3 MYB transcription factors in the regulation of secondary metabolism, cell shape, and disease resistance, and in responses to growth regulators and stresses. For the majority of the genes in this family, however, little functional information is available. As the first step to characterizing these genes functionally, the sequences of >90 family members, and the map positions and expression profiles of >60 members, have been determined previously. An important second step in the functional analysis of the MYB family, through a process of reverse genetics that entails the isolation of insertion mutants, is described here. For this purpose, a variety of gene disruption resources has been used, including T-DNA-insertion populations and three distinct populations that harbor transposon insertions. We report the isolation of 47 insertions into 36 distinct MYB genes by screening a total of 73 genes. These defined insertion lines will provide the foundation for subsequent detailed functional analyses for the assignment of specific functions to individual members of the R2R3 MYB gene family.

Office ergonomics. Measurements for success

The successful implementation of an ergonomics program requires collecting data on worksite history repetitive motion injuries and assessing the corporate ergonomic needs. It is important to solicit management, department, and employee support. Program success depends on creating process, training program, skilled assessors, and an accountability method. A thorough understanding and application of neutral posture and the three seated chair positions is essential. Evaluation of the entire individual work-space is essential. Precise measurements of the individual, the office chair, and the work surfaces should be completed, and heights adjusted to meet individual needs. Functional, totally adjustable office chairs are a necessity. Vendor selection criteria and vendor contracts for chairs and office equipment assure consistent specifications and cost control.

What guides the selection of alternate foot placement during locomotion in humans

Our goal was to understand the bases for selection of alternate foot placement during locomotion when the normal landing area is undesirable. In this study, a light spot of different shapes and sizes simulated an undesirable landing area. Participants were required to avoid stepping on this spot under different time constraints. Alternate chosen foot placements were categorised into one of eight choices. Results showed that selection of alternate foot placement is systematic. There is a single dominant choice for each combination of light spot and normal landing spot. The dominant choice minimises the displacement of the foot from its normal landing spot (less than half a foot length). If several response choices satisfy this criterion, three selection strategies are used to guide foot placement: placing the foot in the plane of progression, choosing to take a longer step over a shorter step and selecting a medial rather than lateral foot placement. All these alternate foot-placement choices require minimal changes to the ongoing locomotor muscle activity, pose minimal threat to dynamic stability, allow for quick initiation of change in ongoing movement and ensure that the locomotor task runs without interruption. Thus, alternate foot-placement choices are dependent not only on visual input about the location, size and shape of the undesirable surface, but also on the relationship between the characteristics of the undesirable surface and the normal landing area.

Project DARE: no effects at 10-year follow-up

The present study examined the impact of Project DARE (Drug Abuse Resistance Education), a widespread drug-prevention program, 10 years after administration. A total of 1,002 individuals who in 6th grade had either received DARE or a standard drug-education curriculum, were reevaluated at age 20. Few differences were found between the 2 groups in terms of actual drug use, drug attitudes, or self-esteem, and in no case did the DARE group have a more successful outcome than the comparison group. Possible reasons why DARE remains so popular, despite the lack of documented efficacy, are offered.

Changes in the expression of myometrial ryanodine receptor mRNAs during human pregnancy

Uterine contraction is triggered by a rise in intracellular free Ca(2+) concentration ([Ca2+]i), and although ryanodine-sensitive Ca(2+) release channels (RyRs) play a key role in the regulation of [Ca(2+)](i) in skeletal and cardiac muscle, much less is known about their role in smooth muscle. In this study, we investigated the expression of RyR mRNAs (ryr1-3) during human pregnancy by examining myometrial samples (n=18) taken, with informed consent and ethical approval, from non-pregnant patients undergoing hysterectomy, and patients undergoing elective caesarean section (at term, prior to or following the onset of labour). Ca(2+) release channel expression was determined both qualitatively and quantitatively, using reverse transcription-polymerase chain reaction (RT-PCR) analysis, RNase protection assays, and in situ mRNA hybridisation. RT-PCR analysis demonstrated that all three ryr genes, as well as the gene encoding the type I inositol 1,4,5-trisphosphate receptor (InsP(3)RI), are expressed in human myometrium. Quantitation by RNase protection assays showed that ryr3 and InsP(3)RI mRNAs are the most abundant, while ryr2 mRNA is barely detectable. In situ mRNA hybridisation confirmed that ryr3 and InsP(3)RI mRNAs are both localised to myometrial smooth muscle cells. The expression of ryr2 and ryr3 mRNA is down-regulated at the end of pregnancy compared to non-pregnant myometrium, indicating that ryanodine-sensitive Ca(2+) release channels are differentially expressed. The relative conservation of ryr1 expression is consistent with a role for Ca(2+) release from ryanodine-sensitive stores in the mechanism of uterine contractility during labour.

[When and how to research anxiety disorders in children?]

From the epidemiological evidence, anxiety disorders appear frequent in childhood and adolescence. Because anxiety has normal adaptative forms through development, the identification of pathology may sometimes pose difficulty. Child and adolescent anxiety disorders are defined in modern classifications with diagnostic criteria nearby of those used for adulthood. Behavioural symptoms of anxiety often alert relatives or teachers of the children. This paper reviews the main behavioural signs found in anxiety disorders (shyness, school refusal, sleep disorders, somatic distress, slowness, domestic tyranny).

Interaction with amylopectin influences the ability of granule-bound starch synthase I to elongate malto-oligosaccharides

This paper examines the properties in soluble form of two isoforms of starch synthase. One of these, granule-bound starch synthase I (GBSSI), is responsible for the synthesis of amylose inside the amylopectin matrix of the starch granule in vivo. The other, starch synthase II (SSII), is involved in amylopectin synthesis. Both isoforms can use amylopectin and malto-oligosaccharide as substrates in vitro. As well as acting as a substrate for GBSSI, amylopectin acts as an effector of this isoform, increasing the rate at which it elongates malto-oligosaccharides and promoting a processive rather than distributive mode of elongation of these compounds. The affinity of GBSSI for amylopectin as an effector is greater than its affinity for amylopectin as a substrate. The rate and mode of elongation of malto-oligosaccharides by SSII are not influenced by amylopectin. These results suggest that specific interaction with amylopectin in the matrix of the starch granule is a unique property of GBSSI and is critical in determining the nature of its products.

Effects of norepinephrine plus dobutamine or norepinephrine alone on left ventricular performance of septic shock patients

OBJECTIVE

To determine the hemodynamic effects of the combination of norepinephrine-dobutamine in adult patients with septic shock. Specifically, we tested the hypothesis that norepinephrine in addition to dobutamine would improve cardiac index (CI) and stroke volume index (SVI) and increase left-ventricular afterload.

DESIGN

Prospective, descriptive, interventional study with no control group.

SETTING

Intensive care unit of a university hospital.

PATIENTS

Fourteen patients (group 1) were transferred to the intensive care unit from other wards with septic shock not responsive to dobutamine infusion, low blood pressure (systolic blood pressure of <90 mm Hg), clinical and laboratory signs of infection, clinical signs of poor organ perfusion, and blood lactate of >2.0 mmol/L. They were enrolled and treated by the addition of norepinephrine, while the dose of dobutamine remained constant. Three of these patients required additional fluid loading to achieve adequate ventricular filling (pulmonary capillary wedge pressure [PCWP], 12-15 mm Hg). These patients were compared with 12 patients with septic shock with high CI (CI > 5/min/m2, and other signs as outlined previously) who were treated with norepinephrine alone (group 2).

INTERVENTIONS

Patients in group 1 were maintained with the same dobutamine dose, and norepinephrine was added (initial dose, 0.5 microg/kg/min, and increments of 0.3 microg/kg/min) until the correction of mean arterial blood pressure (MAP > or =75 mm Hg). Patients in group 2 received norepinephrine following the same protocol.

MEASUREMENTS AND MAIN RESULTS

At study entry, group 1 patients receiving dobutamine had similar MAPs but were significantly older and had significantly lower CIs and SVIs and higher systemic vascular resistance than group 2 patients. In group 1 norepinephrine, in addition to dobutamine, significantly increased MAP, CI, SVI, left ventricular stroke work index (LVSWI), and systemic vascular resistance (SVR). No change in heart rate or PCWP was observed. In group 2, norepinephrine used alone did not modify CI or SVI and it significantly improved MAP, LVSWI, and SVR. No changes in heart rate or PCWP were observed. Blood lactate was significantly decreased in both groups. Comparing the two groups, in response to norepinephrine titrated to increase MAP to a similar concentration, patients with dobutamine-resistant septic shock had a statistically significantly greater increase in CI and SVI than patients treated with norepinephrine alone. There were no other significant differences in hemodynamic and metabolic responses to norepinephrine between groups 1 and 2.

CONCLUSION

The addition of norepinephrine to treatment of patients with septic shock unresponsive to dobutamine significantly improves MAP, CI, SVI, and LVSWI. A different pattern of evolution was observed if norepinephrine was used alone in younger patients with higher CI at study entry, increases in MAP and LVSWI, and no concomitant change in CI or SVI. The use of norepinephrine in dobutamine-resistant septic shock may have some beneficial implications for the treatment of patients with inadequate myocardial performance associated with low SVR.

Early-onset autosomal dominant Alzheimer disease: prevalence, genetic heterogeneity, and mutation spectrum

To determine the prevalence of early-onset Alzheimer disease (EOAD) and of autosomal dominant forms of EOAD (ADEOAD), we performed a population-based study in the city of Rouen (426,710 residents). EOAD was defined as onset of disease at age <61 years, and ADEOAD was defined as the occurrence of at least three EOAD cases in three generations. Using these stringent criteria, we calculated that the EOAD and ADEOAD prevalences per 100,000 persons at risk were 41.2 and 5.3, respectively. We then performed a mutational analysis of the genes for amyloid precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2) in 34 families with ADEOAD ascertained in France. In 19 (56%) of these families, we identified 16 distinct PSEN1 missense mutations, including 4 (Thr147Ile, Trp165Cys, Leu173Trp, and Ser390Ile) not reported elsewhere. APP mutations, including a novel mutation located at codon 715, were identified in 5 (15%) of the families. In the 10 remaining ADEOAD families and in 9 additional autosomal dominant Alzheimer disease families that did not fulfill the strict criteria for ADEOAD, no PSEN1, PSEN2, or APP mutation was identified. These results show that (1) PSEN1 and APP mutations account for 71% of ADEOAD families and (2) nonpenetrance at age <61 years is probably infrequent for PSEN1 or APP mutations.

Utilization of alcohol, drug, and mental health treatment services among American Indian adolescent detainees

OBJECTIVE

To describe the relationship between psychiatric status and the use of alcohol, drug, and mental health (ADM) services among a sample of American Indian (AI) juvenile detainees.

METHOD

A structured diagnostic and service use interview was administered to 150 AI youths detained in a juvenile detention center located on a Northern Plains reservation.

RESULTS

Forty percent of AI youths with a diagnosed substance use disorder and 34.1% with a diagnosed anxiety, mood, or disruptive behavior disorder reported lifetime use of services for substance use and emotional problems, respectively. While services for substance use problems were most commonly provided in residential settings, services for emotional problems were most commonly provided in outpatient settings. Traditional healers and pastoral counselors provided services to 23.7% and 29.6% of youths who received services for substance use and emotional problems, respectively. Detained youths were more likely to receive ADM services than AI adolescents living at--large in another, comparable Northern Plains reservation community. Still, the vast majority of youths in detention who suffered from psychiatric disorders did not report use of ADM services.

CONCLUSIONS

Detention facilities serving AI adolescents need to screen carefully for the presence of psychiatric disorders and facilitate the use of ADM services.

Molecular characterization of mycobacteria isolated from seals

Tuberculosis (TB) was diagnosed in 10 seals from three species (Arctocephalus australis, Arctocephalus tropicalis and Otaria flavescens) found in South America. The mycobacteria isolated from these cases belonged to the Mycobacterium tuberculosis complex, as determined by RFLP using an IS6110 probe, spoligotyping, analysis of the 16S rRNA gene sequence and by PCR-restriction analysis of hsp65. Polymorphisms in gyrA, katG, oxyR and pncA were investigated in some of the isolates, as well as the presence of the MPB70 antigen. The insertion sequence IS6110 was present in three to seven copies in the genome of the mycobacteria isolated from seals. Using the IS6110 probe, six patterns (designated A, B, C, D, E and F) were identified from 10 different isolates. Patterns A and B were found for the mycobacteria isolated from two and four seals, respectively, indicating an epidemiological relationship between isolates grouped according to their IS6110 RFLP. The mycobacteria isolated from seals shared the majority of their IS6110 DNA-containing restriction fragments, and nine isolates had an identical spoligotype; only one isolate showed a minor difference in its spoligotype. In addition, none of these spoligotypes were found in other M. tuberculosis complex strains. These results suggest that the isolates from seals constitute a unique group of closely related strains. The mycobacteria isolated from seals showed polymorphisms at gyrA codon 95 and katG codon 463, as do group 1 M. tuberculosis, and M. bovis. Group 1 mycobacteria are associated with cluster cases. The spoligotypes found in the mycobacteria isolated from seals lack spacers 39-43, as does M. bovis, but the MPB70 antigen, which is highly expressed in M. bovis and minimally expressed in M. tuberculosis, was not detected in these mycobacteria. The mycobacteria isolated from seals also showed oxyR and pncA polymorphisms specific to M. tuberculosis. In conclusion, the mycobacteria that cause TB in seals in the South-Western Atlantic are a related group, and based on the combination of genetic characteristics, belong to a unique genotypic group within the M. tuberculosis complex.

Craniotomy for tumor treatment in an intraoperative magnetic resonance imaging unit

OBJECTIVE

The complex three-dimensional anatomic features of the brain and its vulnerability to surgical intervention make the surgical treatment of intracranial tumors challenging. We evaluated the surgical treatment of supratentorial tumors using intraoperative magnetic resonance imaging (MRI), which provides real-time guidance, allows localization of intracranial tumors and their margins, and facilitates continuous assessment of surgical progress.

METHODS

Sixty patients underwent craniotomies for tumor treatment in the General Electric intraoperative MRI unit at the Brigham and Women's Hospital (Boston, MA) during a 1-year period. The patients selected were those with intracranial tumors that were considered difficult to resect because of their locations or previous incomplete operations. Twenty-nine low-grade and 19 high-grade gliomas, 8 metastatic lesions, 2 meningiomas, 1 pineoblastoma, and 1 astroblastoma were resected.

RESULTS

Tumors were accurately localized and targeted, and the extent of resection, as well as any intraoperative complications, could be immediately assessed during surgery. Marked brain shifting occurred during the procedures, and repeated intraoperative imaging allowed surgical accommodation for this shifting. In more than one-third of the cases, intraoperative imaging showed residual tumor when resection appeared complete on the basis of surgical observation alone.

CONCLUSION

Intraoperative MRI is a revolutionary tool for the surgical treatment of brain tumors, providing observation of the procedure as it is being performed. With intraoperative MRI, tumor resection is safer, the extent of resection can be directly evaluated, and intraoperative complications can be noted if they occur. Outcomes after resection depend on minimizing injury to normal brain tissue and achieving maximal tumor resection. The use of intraoperative MRI directly affects these factors.

An exploration of the sequence of a 2.9-Mb region of the genome of Drosophila melanogaster: the Adh region

A contiguous sequence of nearly 3 Mb from the genome of Drosophila melanogaster has been sequenced from a series of overlapping P1 and BAC clones. This region covers 69 chromosome polytene bands on chromosome arm 2L, including the genetically well-characterized "Adh region." A computational analysis of the sequence predicts 218 protein-coding genes, 11 tRNAs, and 17 transposable element sequences. At least 38 of the protein-coding genes are arranged in clusters of from 2 to 6 closely related genes, suggesting extensive tandem duplication. The gene density is one protein-coding gene every 13 kb; the transposable element density is one element every 171 kb. Of 73 genes in this region identified by genetic analysis, 49 have been located on the sequence; P-element insertions have been mapped to 43 genes. Ninety-five (44%) of the known and predicted genes match a Drosophila EST, and 144 (66%) have clear similarities to proteins in other organisms. Genes known to have mutant phenotypes are more likely to be represented in cDNA libraries, and far more likely to have products similar to proteins of other organisms, than are genes with no known mutant phenotype. Over 650 chromosome aberration breakpoints map to this chromosome region, and their nonrandom distribution on the genetic map reflects variation in gene spacing on the DNA. This is the first large-scale analysis of the genome of D. melanogaster at the sequence level. In addition to the direct results obtained, this analysis has allowed us to develop and test methods that will be needed to interpret the complete sequence of the genome of this species. Before beginning a Hunt, it is wise to ask someone what you are looking for before you begin looking for it. Milne 1926

Malignant degeneration of an osteochondroma with unusual intra-bursal invasion

Multiple hereditary osteochondromatosis is an uncommon autosomal dominant condition in which patients are predisposed to the development of chondrosarcoma. We report a case of a patient who developed a secondary low-grade chondrosarcoma in this setting. The tumor was associated with an unusual multinodular invasive growth pattern into a pre-existing bursa that was present overlying the osteochondroma.

Gonadotrophin and testosterone suppression by 7alpha-methyl-19-nortestosterone acetate administered by subdermal implant to healthy men

The synthetic androgen 7alpha-methyl-19-nortestosterone (MENT) is a potent suppressor of gonadotrophin that has several advantages for long term administration to normal or hypoandrogenic men. The aim of this study was to examine MENT serum concentrations following subdermal insertion of MENT acetate (MENT Ac) implants and their effects on gonadotrophins, testosterone, dihydrotestosterone (DHT), sex hormone-binding globulin, prostate specific antigen and insulin-like growth factor-1 serum concentrations in normal men. A total of 45 healthy men were recruited at three clinics. Each subject received one, two or four implants for 28 days. Serum samples were obtained before insertion and on days 8, 15, 22, 29, 36 and 43 after implant insertion. The average daily dose delivered in vivo by one implant was approximately 500 microg. One, two or four MENT Ac implants produced dose dependent and sustained serum MENT concentrations for the entire duration of treatment of 0.7 +/- 0.1, 1.2 +/- 0.1 and 2.0 +/- 0.1 nmol/l respectively. This treatment induced a dose dependent decrease in gonadotrophin and androgen serum levels. Two and four implants induced maximal suppression that was maintained throughout treatment and was completely reversed after removal of the implants. The mean decreases were 93 +/- 1% for testosterone, 80 +/- 3% for DHT, 97 +/- 1% for luteinizing hormone and 95 +/- 1% for follicle stimulating hormone. No serious adverse reactions were reported by the volunteers and no consistent changes in clinical chemistry and haematology were found. These results indicate that MENT Ac implants are an efficient way of MENT administration and confirm the potent gonadotrophin and androgen suppressive effect of this drug.