Specific factors predict the response to pulsatile gonadotropin-releasing hormone therapy in polycystic ovarian syndrome

Ovulation induction is particularly challenging in patients with polycystic ovarian syndrome (PCOS) and may be complicated by multifollicular development. Pulsatile GnRH stimulates monofollicular development in women with anovulatory infertility; however, ovulation rates are considerably lower in the subgroup of patients with PCOS. The aim of this retrospective study was to determine specific hormonal, metabolic, and ovarian morphological characteristics that predict an ovulatory response to pulsatile GnRH therapy in patients with PCOS. Subjects with PCOS were defined by chronic amenorrhea or oligomenorrhea and clinical and/or biochemical hyperandrogenism in the absence of an adrenal or pituitary disorder. At baseline, gonadotropin dynamics were assessed by 10-min blood sampling, insulin resistance by fasting insulin levels, ovarian morphology by transvaginal ultrasound, and androgen production by total testosterone levels. Intravenous pulsatile GnRH was then administered. During GnRH stimulation, daily blood samples were analyzed for gonadotropins, estradiol (E(2)), progesterone, inhibin B, and androgen levels, and serial ultrasounds were performed. Forty-one women with PCOS underwent a total of 144 ovulation induction cycles with pulsatile GnRH. Fifty-six percent of patients ovulated with 40% of ovulatory patients achieving pregnancy. Among the baseline characteristics, ovulatory cycles were associated with lower body mass index (P < 0.05), lower fasting insulin (P = 0.02), lower 17-hydroxyprogesterone and testosterone responses to hCG (P < 0.03) and higher FSH (P < 0.05). In the first week of pulsatile GnRH treatment, E(2) and the size of the largest follicle were higher (P < 0.03), whereas androstenedione was lower (P < 0.01) in ovulatory compared with anovulatory patients. Estradiol levels of 230 pg/mL (844 pmol/L) or more and androstenedione levels of 2.5 ng/mL (8.7 nmol/L) or less on day 4 and follicle diameter of 11 mm or more by day 7 of pulsatile GnRH treatment had positive predictive values for ovulation of 86.4%, 88.4%, and 99.6%, respectively. Ovulatory patients who conceived had lower free testosterone levels at baseline (P < 0.04). In conclusion, pulsatile GnRH is an effective and safe method of ovulation induction in a subset of patients with PCOS. Patient characteristics associated with successful ovulation in response to pulsatile GnRH include lower body mass index and fasting insulin levels, lower androgen response to hCG, and higher baseline FSH. In ovulatory patients, high free testosterone is negatively associated with pregnancy. A trial of pulsatile GnRH therapy may be useful in all PCOS patients, as E(2) and androstenedione levels on day 4 or follicle diameter on day 7 of therapy are highly predictive of the ovulatory response in this group of patients.

A technical approach for optimizing surveillance of patients with unstable coronary syndromes: continuous vectorcardiography ischemic monitoring

Continuous vectorcardiography ischemic monitoring (VCG) is a noninvasive technique which has contributed much to our understanding of the dynamics of acute coronary syndromes. For risk assessment of patients with unstable angina pectoris or non-Q-wave myocardial infarction, VCG shows important prognostic power which is further enhanced by its combination with the measurement of highly sensitive and specific biochemical markers of myocardial injury. VCG surveillance after revascularization therapy of Q-wave myocardial infarction is widely accepted because of its potential of assessing vessel patency, of estimating infarct size, and of revealing residual myocardial ischemia. Valuable prognostic information is available in real time with VCG, and treatment strategies may be based upon more reliable grounds. In this survey, the VCG technique is presented together with the most frequently used vectorcardiographic variables. Further, the use of the method for risk stratification of patients with unstable coronary syndromes is also described.

Obstacles to residents' conducting research and predictors of publication

Internal medicine residents at one school identified barriers to and predictors of publishing their research. Insufficient time was the key obstacle to completing research. Residents with previous research experience, senior residents, and men were more likely to publish.

Hyperkinetic movement disorder in an 11-year-old child treated with bilateral pallidal stimulators

Pallidal stimulation is widely used in the treatment of movement disorder in adults but is less well reported in the treatment of dystonia in children. Despite inconsistent results in the past, its use in dystonia in Parkinson's disease is again attracting interest with promising results. Bilateral as well as unilateral pallidotomies have been performed and are felt to be required in some cases of dystonia. Use of depth electrodes to provide long-term electrical stimulation to pallidum and other basal ganglia structures has recently become more widespread. This technique is felt to have a lower morbidity, especially in bilateral procedures. Here we present the case of an 11-year-old boy with severe hyperkinetic movement disorder who showed sustained improvement after bilateral pallidal stimulation implantation.

Determination of optimal peat type to potentially capture copper and cadmium from solution

The focus of this study was to determine the optimum type of peat for application as a medium to capture dissolved metals from aqueous solution. Seventeen media were examined, including eleven Irish peat samples from various locations and stages in processing, a Northern Ireland lignite, peat and lignite chars, a commercial-grade bone char, and two commercial-grade granular activated carbons. Considerable variation in sorption capacity was found with a ratio of 20:1 between the best-performing (bone char) and the poorest-performing (peat char) samples. Among the 14 varieties of peat, the best-performing sample outperformed the commonly investigated sphagnum moss by a ratio of 4:1. A correlation has been established between cation exchange capacity, the presence of adsorbed calcium, and the uptake capacity of different peats. This correlation will be a valuable tool in choosing peat type for filter media for metals removal applications.

Clinical implications of rhinoceros reproductive tract anatomy and histology

Reproductive tracts or tissues from five male black rhinoceroses (Diceros bicornis), two male white rhinoceroses (Ceratotherium simum), two male one-horned Asian rhinoceroses (Rhinoceros unicornis), seven female black rhinoceroses, and six female white rhinoceroses from multiple institutions were examined to characterize their anatomy and histology. Some observations and measurements were obtained from in situ tracts of intact animals before or during necropsy. Formalin-fixed tissues were dissected and examined histologically. Retrospective reproductive data from each rhinoceros was obtained from the institutions of origin. Reproductive histology of these species was similar to that of other mammals. Male accessory gland structure varied among species, and the Asian rhinoceros epididymis was more loosely attached and had larger duct diameters than did the epididymides of the African species. Although histology was typically mammalian, rhinoceros reproductive morphology combined characteristics of several different mammals. Defining this unique morphology of rhinoceroses may help in understanding their reproductive physiology and will effect the development of appropriate reproductive techniques.

Early reperfusion assessment and repeated thrombolysis in acute myocardial infarction estimated by repeated standard electrocardiography. A randomised, double-blind, placebo-controlled pilot study

Thrombolytic therapy with streptokinase (SK) in acute myocardial infarction (AMI) does not result in early reperfusion in approximately 25% of patients. We hypothesized that early repeated thrombolysis with rt-PA in patients with early failed reperfusion would result in myocardial reperfusion. Fifty-nine AMI patients with a symptom delay of <6 h, treated with SK were included. ECG was taken on admission and after 90 and 180 min. An ST recovery of > or =25% at 90 min was interpreted as successful reperfusion. Sixteen patients had failed reperfusion at 90 min and were randomized to repeated thrombolysis with rt-PA or placebo. At 180 min from SK start, ST recovery was higher in the placebo group than in the rt-PA group (71 vs. 40%, p = 0.05). No serious bleeding complications were observed. Due to the limited sample size it was not possible to draw prominent conclusions.

Evaluating the efficacy of amikacin in low-clearance unilamellar liposomes in a s. Aureus local infection model

Traditional therapies for Staphylococcal infections such as osteomyelitis or localized abscesses have a difficult time penetrating into tissue sites. To effectively ameliorate these infections, prolonged therapy and/or high doses of antibiotics are frequently required. Aminoglycosides, such as amikacin, are not routinely utilized for treating local infections due to poor efficacy associated with ineffective tissue penetration, toxicity, and poor penetration in an acid millieu. We postulated that a formulation of amikacin in small unilamellar liposomes might readily be engulfed by inflammatory macrophages facilitating drug delivery to the site of infection. This increased drug load to the site of bacterial infection may result in enhanced bactericidal action compared to conventional aminoglycosides. Tissue drug concentrations were determined for liposomal amikacin (L-AN) and conventional amikacin (AN). Plasma amikacin levels were determined for L-AN. The L-AN was very effective at concentrating at the site of infection compared to AN. Following confirmation of adequate tissue drug levels, a rodent subcutaneous abscess infection using S. aureus as the bacterial challenge agent was evaluated. Sprague-Dawley rats were intravenously administered L-AN every other day due to its prolonged half-life, while the comparator agent, AN, was administered daily. Abscess size, weights, severity, histology, and tissue colony counts were examined. In efficacy studies, L-AN was superior to AN in reducing colony counts.

Antibiotic resistance as a stress response: complete sequencing of a large number of chromosomal loci in Staphylococcus aureus strain COL that impact on the expression of resistance to methicillin

Tn551 inactivation has identified several determinants--fem or auxiliary genes--that, in addition to the mecA gene, are also critical for the expression of high-level and homogeneous resistance to methicillin. Genetic and/or biochemical analysis has shown that of the nearly dozen aux mutations described so far most are in genes involved in cell wall synthesis (murE, pbp2, glmM, glnR, femA/B, llm, etc.) or in complex regulatory functions (sigmaB), suggesting that optimal expression of resistance may involve the cooperative functioning of a number of genes in cell wall metabolism as well as stress response. The exact mechanism of these functions is not known. In an attempt to explore this unusual aspect of methicillin resistance more fully, a Tn551 transposon library, constructed in the background of the highly and homogeneously methicillin-resistant Staphylococcus aureus strain COL, was screened for all independent insertional mutants in which the level of methicillin resistance of the parental strain (MIC, 1,600 microg/ml) was reduced by at least 15-fold and up to 500-fold. We now describe the sequencing of 21 Tn551-inactivated genes and their vicinities in 23 new auxiliary mutants that have been studied before. Using the inverted polymerase chain reaction (IPCR), we amplified fragments corresponding to the right and left junction of the Tn551 insertions, which were then sequenced by primer walking. The two largest groups of these new auxiliary genes encoded either proteins of unknown functions (6 genes) or showed homology with genes encoding proteins involved with putative sensory/regulatory activities (7 genes: protein kinases, ABC transporters, and a catabolite control protein). Sequencing upstream and downstream allowed the identification of a number of additional open reading frames, some of which may also include functions relevant for the expression of antibiotic resistance.

Liposomal lurtotecan (NX211): determination of total drug levels in human plasma and urine by reversed-phase high-performance liquid chromatography

Lurtotecan (GI147211; LRT) is a semisynthetic and water-soluble analogue of the topoisomerase I inhibitor camptothecin. To determine whether the therapeutic efficacy of LRT in patients could be improved, the drug was encapsulated in liposomes (NX211; Gilead Sciences). In order to allow accurate description of the pharmacokinetic behavior of NX211 in cancer patients, we have developed sensitive RP-HPLC assays with fluorescence detection (lambdaex=378 nm; lambdaem=420 nm) for the determination of total LRT levels in human plasma and urine. Sample pretreatment involved deproteinization with 10% (w/v) aqueous perchloric acid-acetonitrile (2:1, v/v), and chromatographic separations were achieved on an Inertsil-ODS 80A analytical column. The lower limit of quantitation (LLQ) was established at 1.00 ng/ml in plasma (200-microl sample) and at 100 ng/ml in urine (200 microl of 40-fold diluted sample). The within-run and between-run precisions were <7.5%. LRT concentrations in urine of <100 ng/ml were determined by a modified procedure comprising a single solvent extraction with n-butanol-diethyl ether (3:4, v/v). In this assay, the fluorescence signal of LRT was increased 14-fold prior to detection by post-column exposure to UV light (254 nm) in a photochemical reaction unit. The LLQ of this assay was 0.500 ng/ml (150-microl sample) and the within-run and between-run precisions were <10%.

Development and preliminary evaluation of an instrument designed to assess dental students' communication skills

The aim of this study was to develop, and assess the inter-observer reliability of an instrument for evaluating dental students' communication skills. Methods used were process-tracking of interactions between experienced practitioners and patients, development of the instrument and its simultaneous use by two researchers observing 43 third year dental students prior to communication skills training. The results found that the instrument was appropriate for the purpose for which it was designed, and was easy to utilise. There were no significant differences between observers' total scores. Item-specific weighted kappa scores showed almost perfect agreement between observers for all but four of the 31 items. The lowest interobserver weighted kappa score was for the measurement of eye contact (k = 0.60). In conclusion, assessment of communication skills is now a necessity in the undergraduate curriculum. Preliminary analysis of an instrument of communication skills in the dental surgery indicates that it may be possible to do this reliably.

Cloning, genomic organization and expression of a putative human transmembrane protein related to the Caenorhabditis elegans M01F1.4 gene

A novel human transcript CG-2 (C9ORF5), was isolated from the familial dysautonomia candidate region on 9q31 using a combination of cDNA selection and exon trapping. CG-2 was detected as a relatively abundant 8kb transcript in all adult and fetal tissues with the exception of adult thymus. Genomic analysis of CG-2 identified 18 exons that span more than 110kb. The gene encodes a 911-amino-acid protein with a predicted molecular weight of 101kDa and a hypothetical pI of 9.03. Sequence analysis of CG-2 indicates that it is likely to encode a transmembrane protein. Here, we assess CG-2 as a candidate for familial dysautonomia.

BCL10 is rarely mutated in human prostate carcinoma, small-cell lung cancer, head and neck tumours, renal carcinoma and sarcomas. MPT Collaborators, St George's Hospital Collaborators

We have used single-strand conformation polymorphism (SSCP) analysis to screen for mutations in the BCL10 gene in 81 primary prostate carcinomas, 20 squamous cell cancers of the head and neck, 15 small-cell lung cancer cell lines, 24 renal carcinoma cell lines and 13 sarcoma cell lines. We failed to find evidence of somatically acquired mutations of the BCL10 gene suggesting that BCL10 does not play a major role in the development of these malignancies.

Cloning, mapping, and expression of two novel actin genes, actin-like-7A (ACTL7A) and actin-like-7B (ACTL7B), from the familial dysautonomia candidate region on 9q31

Two novel human actin-like genes, ACTL7A and ACTL7B, were identified by cDNA selection and direct genomic sequencing from the familial dysautonomia candidate region on 9q31. ACTL7A encodes a 435-amino-acid protein (predicted molecular mass 48.6 kDa) and ACTL7B encodes a 415-amino-acid protein (predicted molecular mass 45. 2 kDa) that show greater than 65% amino acid identity to each other. Genomic analysis revealed ACTL7A and ACTL7B to be intronless genes contained on a common 8-kb HindIII fragment in a "head-to-head" orientation. The murine homologues were cloned and mapped by linkage analysis to mouse chromosome 4 in a region of gene order conserved with human chromosome 9q31. No recombinants were observed between the two genes, indicating a close physical proximity in mouse. ACTL7A is expressed in a wide variety of adult tissues, while the ACTL7B message was detected only in the testis and, to a lesser extent, in the prostate. No coding sequence mutations, genomic rearrangements, or differences in expression were detected for either gene in familial dysautonomia patients.

Precise genetic mapping and haplotype analysis of the familial dysautonomia gene on human chromosome 9q31

Familial dysautonomia (FD) is an autosomal recessive disorder characterized by developmental arrest in the sensory and autonomic nervous systems and by Ashkenazi Jewish ancestry. We previously had mapped the defective gene (DYS) to an 11-cM segment of chromosome 9q31-33, flanked by D9S53 and D9S105. By using 11 new polymorphic loci, we now have narrowed the location of DYS to <0.5 cM between the markers 43B1GAGT and 157A3. Two markers in this interval, 164D1 and D9S1677, show no recombination with the disease. Haplotype analysis confirmed this candidate region and revealed a major haplotype shared by 435 of 441 FD chromosomes, indicating a striking founder effect. Three other haplotypes, found on the remaining 6 FD chromosomes, might represent independent mutations. The frequency of the major FD haplotype in the Ashkenazim (5 in 324 control chromosomes) was consistent with the estimated DYS carrier frequency of 1 in 32, and none of the four haplotypes associated with FD was observed on 492 non-FD chromosomes from obligatory carriers. It is now possible to provide accurate genetic testing both for families with FD and for carriers, on the basis of close flanking markers and the capacity to identify >98% of FD chromosomes by their haplotype.

Telomerase repressor sequences on chromosome 3 and induction of permanent growth arrest in human breast cancer cells

BACKGROUND

Activation of the enzyme telomerase, which has been associated with cellular immortality, may constitute a key step in the development of human cancer. Telomerase is repressed in most normal human somatic cells. This study was conducted, using a genetic complementation approach, with the aim of identifying and mapping the genes responsible for repressing telomerase and, simultaneously, to establish the effect of experimentally induced telomerase repression on human tumor cell growth.

METHODS

Individual human chromosomes isolated from normal diploid cells and tagged with bacterial antibiotic resistance genes (for later selection) were introduced into cells of the human breast carcinoma cell line 21NT by means of microcell transfer. Selected hybrid clones were screened for telomerase activity by use of the polymerase chain reaction-based telomere repeat amplification protocol (TRAP) assay, and the proliferative fate of the hybrid clones was determined. Regions of the introduced chromosomes associated with telomerase repression were mapped using segregant hybrids and a deletion analysis that employed microsatellite DNA markers.

RESULTS

Strong repression of telomerase was observed following transfer of human chromosome 3 into 21NT cells but not after transfer of chromosomes 8, 12, or 20. The vast majority of hybrid clones with repressed telomerase entered permanent growth arrest after 10-18 population doublings. Deletion analysis of nonrepressed segregant monochromosome 3 hybrids indicated two regions on the short arm of chromosome 3 (3p21.3-p22 and 3p12-21.1) where telomerase regulator genes may be located.

CONCLUSIONS

Telomerase in human breast cancer cells is efficiently repressed by a gene or genes on normal human chromosome 3p, and this repression is associated with permanent growth arrest of the tumor cells.

Linkage analysis of chromosome 1q markers in 136 prostate cancer families. The Cancer Research Campaign/British Prostate Group U.K. Familial Prostate Cancer Study Collaborators

Prostate cancer shows evidence of familial aggregation, particularly at young ages at diagnosis, but the inherited basis of familial prostate cancer is poorly understood. Smith et al. recently found evidence of linkage to markers on 1q, at a locus designated "HPC1," in 91 families with multiple cases of early-onset prostate cancer. Using both parametric and nonparametric methods, we attempted to confirm this finding, in 60 affected related pairs and in 76 families with three or more cases of prostate cancer, but we found no significant evidence of linkage. The estimated proportion of linked families, under a standard autosomal dominant model, was 4%, with an upper 95% confidence limit of 31%. We conclude that the HPC1 locus is responsible for only a minority of familial prostate cancer cases and that it is likely to be most important in families with at least four cases of the disease.

The complete genome sequence of the hyperthermophilic, sulphate-reducing archaeon Archaeoglobus fulgidus

Archaeoglobus fulgidus is the first sulphur-metabolizing organism to have its genome sequence determined. Its genome of 2,178,400 base pairs contains 2,436 open reading frames (ORFs). The information processing systems and the biosynthetic pathways for essential components (nucleotides, amino acids and cofactors) have extensive correlation with their counterparts in the archaeon Methanococcus jannaschii. The genomes of these two Archaea indicate dramatic differences in the way these organisms sense their environment, perform regulatory and transport functions, and gain energy. In contrast to M. jannaschii, A. fulgidus has fewer restriction-modification systems, and none of its genes appears to contain inteins. A quarter (651 ORFs) of the A. fulgidus genome encodes functionally uncharacterized yet conserved proteins, two-thirds of which are shared with M. jannaschii (428 ORFs). Another quarter of the genome encodes new proteins indicating substantial archaeal gene diversity.

Fusion of splicing factor genes PSF and NonO (p54nrb) to the TFE3 gene in papillary renal cell carcinoma

We demonstrate that the cytogenetically defined translocation t(X;1)(p11.2;p34) observed in papillary renal cell carcinomas results in the fusion of the splicing factor gene PSF located at 1p34 to the TFE3 helix-loop-helix transcription factor gene at Xp11.2. In addition we define an X chromosome inversion inv(X)(p11.2;q12) that results in the fusion of the NonO (p54nrb) gene to TFE3. NonO (p54nrb), the human homologue of the Drosophila gene NonAdiss which controls the male courtship song, is closely related to PSF and also believed to be involved in RNA splicing. In each case the rearrangement results in the fusion of almost the entire splicing factor protein to the TFE3 DNA-binding domain. These observations suggest the possibility of intriguing links between the processes of RNA splicing, DNA transcription and oncogenesis.

Ticlopidine-associated pancytopenia: implications of an acetylsalicylic acid alternative

Ticlopidine is an antiplatelet agent that has been proven efficacious in preventing vascular events in patients with a history of vasculopathy. Neutropenia is a significant adverse effect and pancytopenia is rarely reported. A fatal case of pancytopenia associated with unmonitored use of ticlopidine is presented. A 59-year-old woman presented with severe pneumonia and profound neutropenia (absolute neutrophil count 0%). She deteriorated with development of acute respiratory distress syndrome and a marked reduction in trilineage hematopoiesis. Despite prompt marrow response to granulocyte macrophage colony-stimulating factor (GM-CSF) and cessation of ticlopidine, appropriate antibiotics and other supportive therapy, she died 17 days after admission. Hematological monitoring is imperative to identify potential complications: if discovered late, there may be a role for GM-CSF for marrow support. Ticlopidine is indicated for patients intolerant of or nonresponsive to acetylsalicylic acid therapy. As the use of ticlopidine increases, clinicians must be aware of potential life-threatening complications associated with its use and monitor appropriately.

The complete genome sequence of the gastric pathogen Helicobacter pylori

Helicobacter pylori, strain 26695, has a circular genome of 1,667,867 base pairs and 1,590 predicted coding sequences. Sequence analysis indicates that H. pylori has well-developed systems for motility, for scavenging iron, and for DNA restriction and modification. Many putative adhesins, lipoproteins and other outer membrane proteins were identified, underscoring the potential complexity of host-pathogen interaction. Based on the large number of sequence-related genes encoding outer membrane proteins and the presence of homopolymeric tracts and dinucleotide repeats in coding sequences, H. pylori, like several other mucosal pathogens, probably uses recombination and slipped-strand mispairing within repeats as mechanisms for antigenic variation and adaptive evolution. Consistent with its restricted niche, H. pylori has a few regulatory networks, and a limited metabolic repertoire and biosynthetic capacity. Its survival in acid conditions depends, in part, on its ability to establish a positive inside-membrane potential in low pH.

Satisfaction with nursing care: a comparison of patients with HIV/AIDS, non-HIV/AIDS infectious diseases, and medical diagnoses

The purpose of this study was to describe patients' perceptions of nursing care and compare those perceptions based on patients' diagnoses (HIV/AIDS, non-HIV/AIDS infectious diseases, and medical diagnoses). One hundred forty-two patients on five units in a major medical center were surveyed using the Patient Satisfaction Instrument. In addition, 126 staff nurses completed the AIDS Vulnerability Survey. Results of data analysis indicated a statistically significant difference in patient satisfaction with nursing care among patients in the medical group compared to patients in the HIV/AIDS group, with the medical group being more satisfied with their nursing care. Further, there was a statistically significant difference across units between nurses' knowledge, attitude, and fear. In spite of their knowledge base related to HIV/AIDS, nurses felt vulnerable when providing care to this population, thus perpetuating fear and negative attitudes. Additional research into the dynamics of these relationships is imperative as we continue to see increases in the number of patients with HIV/AIDS.

Traumatic subarachnoid-pleural fistula

BACKGROUND

Traumatic subarachnoid-pleural fistula is a very uncommon but important condition. Only 21 cases have been reported so far in the world literature.

METHODS

We encountered 2 cases of subarachnoid-pleural fistula, both in pediatric patients presenting without any neurologic deficit. Whereas our first patient presented with recurrent, rapidly filling clear pleural effusions with an obscure cause, posing a diagnostic problem for the pediatricians, the second patient had trauma to the pleura and dura mater by the sharp edge of Kirschner wire, with impending risk of injury to spinal cord and infection.

RESULTS

Surgical intervention was undertaken after we had a strong suspicion of subarachnoid-pleural fistula in both cases. A subarachnoid-pleural fistula was found at the level of the eleventh thoracic vertebra in the first patient and at the level of the eighth thoracic vertebra in the second patient. Autogenous tissues (mediastinal pleural flap and hammered intercostal muscle covered with methylcellulose) were used to repair the fistula. The subarachnoid space was decompressed with a lumbar drain in the second patient.

CONCLUSIONS

The diagnosis of subarachnoid-pleural fistula is difficult when it is not associated with any neurologic deficit. We found that a high degree of suspicion and early surgical intervention to repair the fistula are rewarding.

The t(X;1)(p11.2;q21.2) translocation in papillary renal cell carcinoma fuses a novel gene PRCC to the TFE3 transcription factor gene

The specific chromosomal translocation t(X;1)(p11.2;q21.2) has been observed in human papillary renal cell carcinomas. In this study we demonstrated that this translocation results in the fusion of a novel gene designated PRCC at 1q21.2 to the TFE3 gene at Xp11.2. TFE3 encodes a member of the basic helix-loop-helix (bHLH) family of transcription factors originally identified by its ability to bind to microE3 elements in the immunoglobin heavy chain intronic enhancer. The translocation is predicted to result in the fusion of the N-terminal region of the PRCC protein, which includes a proline-rich domain, to the entire TFE3 protein. Notably the generation of the chimaeric PRCC-TFE3 gene appears to be accompanied by complete loss of normal TFE3 transcripts. This work establishes that the disruption of transcriptional control by chromosomal translocation is important in the development of kidney carcinoma in addition to its previously established role in the aetiology of sarcomas and leukaemias.

Regulation of intracellular level of Na+, K+ and glycerol in Saccharomyces cerevisiae under osmotic stress

The intracellular level of Na+ and K+ ofS. cerevisiae strain AB1375 revealed that under KCl as well as sorbitol stress, the cationic level was comparable to the level under no stress conditions. On the other hand, there was a sharp drop in the intracellular K+ content and increase in the Na+ content on addition of NaCl to the medium. However, the total cationic level was close to that under control conditions. In addition to changes in the cationic level, an enhanced production and accumulation of glycerol were also observed under osmotic stress. A regulatory mechanism co-ordinating the intracellular concentration of glycerol as well as Na+, K+ content under osmotic stress conditions has been proposed.

Interphase fluorescence in situ hybridization and reverse transcription polymerase chain reaction as a diagnostic aid for synovial sarcoma

Identification of the t(X;18)(p11.2;q11.2) that is associated with a high proportion of synovial sarcoma can be a useful diagnostic aid. The translocation results in fusion of the SYT gene on chromosome 18 to either the SSX1 or the SSX2 gene, two homologous genes within Xp11.2. Two-color interphase fluorescence in situ hybridization and reverse transcription polymerase chain reaction were assessed as approaches to identify the rearrangement in well characterized cases. The presence of the translocation, and the specific chromosome X gene disrupted, were inferred from the configuration of signals from chromosome-specific centromere probes, paints, and markers flanking each gene in preparations of interphase nuclei. Rearrangement was found in two cell lines and eight of nine tumor samples, including analysis of five touch imprints. This was consistent with cytogenetic data in four cases and reverse transcription polymerase chain reaction analysis using primers known to amplify both SYT-SSX1 and SYT-SSX2 transcripts. The transcripts were distinguished by restriction with LspI and SmaI. Contrary to previous suggestions, there was no obvious correlation between histological subtype and involvement of the SSX1 or SSX2 gene. These approaches could also be applied to the identification of tumor-free margins and metastatic disease.

Reference ranges and sources of variability of CD4 counts in HIV-seronegative women and men

BACKGROUND

CD4 lymphocyte counts are used to monitor immune status in HIV disease. An understanding of the variability of CD4 counts which occurs in the absence of HIV infection is essential to their interpretation. The sources and degree of such variability have not been extensively studied.

OBJECTIVES

To establish reference ranges for CD4 counts in HIV-seronegative women and heterosexual men attending a genitourinary medicine (GUM) clinic, and to identify possible differences according to gender and cigarette smoking and, in women, any effect of the menstrual cycle, oral contraceptive use and cigarette smoking.

DESIGN

Female and heterosexual male patients attending a GUM clinic and requesting an HIV-antibody test were recruited prospectively. Results from an earlier study of CD4 counts in homosexual men were available for comparison.

METHODS

Lymphocyte subpopulation analysis on whole blood by flow cytometry.

RESULTS

The absolute CD4 count and percentage of CD4 cells (CD4%) were significantly higher in women (n = 195) than heterosexual men (n = 91) [difference between the means 111 x 106/1 (95% CI 41, 180) and 3.1% (1.30, 4.88)]. The absolute CD4 count and CD4% were also significantly higher in smokers (n = 143) than non-smokers (n = 140) [difference 143 (79, 207) and 2.1% (0.43, 3.81)]. Reference ranges for absolute CD4 counts (geometric mean +/- 2SD) were calculated on log transformed data as follows; female smokers 490-1610, female non-smokers 430-1350, heterosexual male smokers 380-1600, heterosexual male non-smokers 330-1280. Among other variables examined, combined oral contraceptive pill use was associated with a trend towards a lower absolute CD4 count. Changes were seen in CD4% with the menstrual cycle. CD4 counts and CD4% did not differ significantly between heterosexual men and homosexual men (n = 45).

CONCLUSION

There is a significant gender and smoking effect on CD4 counts. The effects of oral contraceptive use and the menstrual cycle warrant further investigation.

Fusion of the EWS gene to CHN, a member of the steroid/thyroid receptor gene superfamily, in a human myxoid chondrosarcoma

The specific chromosomal translocation t(9;22)(q22-31;q11-12) has been observed in the myxoid variant of human chondrosarcoma. In agreement with this observation we report that the EWS gene located at chromosome band 22q12 becomes fused to CHN, a member of the steroid/thyroid receptor gene superfamily located at 9q22-31, in a skeletal myxoid chondrosarcoma. CHN appears to be the human homologue of the rat gene NOR1, which was recently identified as a sequence overexpressed in rat brain cells undergoing apoptosis. Our results also indicate that the chimaeric EWS-CHN gene encodes a EWS-CHN fusion protein in which the C-terminal RNA-binding domain of EWS is replaced by the entire CHN protein, comprising a long N-terminal domain, a central DNA binding domain and a C-terminal ligand-binding/dimerisation domain.

c-Src regulates the simultaneous rearrangement of actin cytoskeleton, p190RhoGAP, and p120RasGAP following epidermal growth factor stimulation

Analysis of C3H10T1/2 murine fibroblasts overexpressing wild type and dominant negative variants of c-Src has demonstrated a requirement for c-Src in EGF-induced mitogenesis. Correlating with the ability of c-Src variants to potentiate or inhibit EGF-dependent DNA synthesis is the phosphotyrosine content of multiple cellular proteins, including p190-RhoGAP, a protein thought to regulate growth factor-induced actin cytoskeleton remodeling by modulating the activity of the small GTP binding protein, Rho. Because the in vivo phosphotyrosine content of p190 varies with the level of active c-Src and not with EGF treatment, p190 is considered to be a preferred substrate of c-Src. To determine whether tyrosyl phosphorylation of p190 (by c-Src) could influence EGF-dependent actin remodeling, we used conventional and confocal immunofluorescence microscopy to examine the intracellular distribution of p190, actin, and p120RasGAP in EGF-stimulated or unstimulated 10T1/2 Neo control cells and cells that stably overexpress wild-type (K+) or kinase-defective (K-) c-Src. We found that in all cell lines, EGF induced a rapid and transient condensation of p190 and RasGAP into cytoplasmic, arclike structures. However, in K+ cells the rate of appearance and number of cells exhibiting arcs increased when compared with control cells. Conversely, K- cells exhibited delayed arc formation and a reduction in number of cells forming arcs. EGF-induced actin stress fiber disassembly and reassembly occurred with the same kinetics and frequency as did p190 and RasGAP rearrangements in all three cell lines. These results, together with the documented Rho-GAP activity intrinsic to p190 and the ability of Rho to modulate actin stress fiber formation, suggest that c-Src regulates EGF-dependent actin cytoskeleton reorganization through phosphorylation of p190.

Fusion of SYT to two genes, SSX1 and SSX2, encoding proteins with homology to the Kruppel-associated box in human synovial sarcoma

We demonstrate that the cytogenetically defined translocation t(X;18)(p11.2;q11.2) found in human synovial sarcoma results in the fusion of the chromosome 18 SYT gene to either of two distinct genes, SSX1 or SSX2, at Xp11.2. The SSX1 and SSX2 genes encode closely related proteins (81% identity) of 188 amino acids that are rich in charged amino acids. The N-terminal portion of each SSX protein exhibits homology to the Kruppel-associated box (KRAB), a transcriptional repressor domain previously found only in Kruppel-type zinc finger proteins. PCR analysis demonstrates the presence of SYT-SSX1 or SYT-SSX2 fusion transcripts in 29 of 32 of the synovial sarcomas examined, indicating that the detection of these hybrid transcripts by PCR may represent a very useful diagnostic method. Sequence analysis has demonstrated heterogeneity in the fusion transcripts with the formation of two distinct SYT-SSX1 fusion junctions and two distinct SYT-SSX2 fusion junctions.

Fusion of the EWS gene to a DNA segment from 9q22-31 in a human myxoid chondrosarcoma

Southern blot analyses revealed a rearrangement of the EWS gene in a skeletal human myxoid chondrosarcoma. Interphase fluorescence in situ hybridization (FISH) studies, using cosmid clones F7 and G9 that flank the EWS locus on 22q12, confirmed the presence of this EWS gene abnormality. Cloning the rearranged EWS DNA fragment and mapping by FISH demonstrated that the EWS gene is joined to DNA sequences localised in 9q22-31. These findings are consistent with previous cytogenetic reports of a recurrent t(9;22)(q22-31;q11-12) in the myxoid variant of chondrosarcoma and reveal involvement of the EWS gene in a fourth type of human sarcoma.

The human SB1.8 gene (DXS423E) encodes a putative chromosome segregation protein conserved in lower eukaryotes and prokaryotes

We report that the human gene SB1.8 (DXS423E) encodes a protein of 1233 amino acids that is highly homologous (30% identity) to the essential yeast protein SMC1 which is required for the segregation of chromosomes at mitosis. Both SB1.8 and SMC1 contain an N-terminal NTP binding site, a central coiled-coil region and a C-terminal helix-loop-helix domain, and have structural features in common with the force generating proteins myosin and kinesin. SB1.8 also exhibits regions of homology and overall structural similarity to the prokaryote (Mycoplasma hyorhinis) protein 115p. Thus SB1.8 and SMC1 are members of a highly conserved and ubiquitous family of proteins that appear to have a fundamental role in cell division. In addition we show that SB1.8 (DXS423E) maps to a cosmid contig that lies centromeric to the OATL2 locus at chromosome Xp11.2.

Mapping the X chromosome breakpoint in two papillary renal cell carcinoma cell lines with a t(X;1)(p11.2;q21.2) and the first report of a female case

A t(X;1)(p11.2;q21.2) has been reported in cases of papillary renal cell tumors arising in males. In this study two cell lines derived from this tumor type have been used to indicate the breakpoint region on the X chromosome. Both cell lines have the translocation in addition to other rearrangements and one is derived from the first female case to be reported with the t(X;1)(p11.2;q21.2). Fluorescence in situ hybridization (FISH) has been used to position YACs belonging to contigs in the Xp11.2 region relative to the breakpoint. When considered together with detailed mapping information from the Xp11.2 region the position of the breakpoint in both cell lines was suggested as follows: Xpter-->Xp11.23-OATL1-GATA1-WAS-TFE3-SY P-t(X;1)-DXS255-CLCN5-DXS146-OATL2- Xp11.22-->Xcen. The breakpoint was determined to lie in an uncloned region between SYP and a YAC called FTDM/1 which extends 1 Mb distal to DXS255. These results are contrary to the conclusion from previous FISH studies that the breakpoint was near the OATL2 locus, but are consistent with, and considerably refine, the position that had been established by molecular analysis.

Patterns of practice analysis for acute myocardial infarction

OBJECTIVE

To assess the level of use of acetylsalicylic acid (ASA), beta-blockers and thrombolytic therapy--proven efficacious therapies in the management of acute myocardial infarction (AMI)--in contemporary patients admitted with AMI, and to assess the role of contraindications and other patient-specific factors in the use or nonuse of these treatments.

DESIGN

The demographics and treatment course of patients admitted with a diagnosis of AMI were reviewed. Specifically targeted therapies were ASA, beta-blockers and thrombolytic therapy. Rates of use were calculated as 'gross utilization' (overall use) and 'adjusted utilization' (accounting for late presentation to hospital, initially equivocal diagnosis or contraindications).

SETTING

Tertiary care hospital in suburban Vancouver, British Columbia.

PATIENTS

A total of 372 consecutive patients admitted to Royal Columbian Hospital between September 1, 1990 and September 1, 1991.

INTERVENTIONS

None.

MAIN RESULTS

Gross utilization of ASA, beta-blockers and thrombolytic therapy was 71, 31 and 21%, respectively. The adjusted utilization rates for early (6 h or less) treatment with ASA was 66%; with early beta-blockers, it was 18% and was 100% for thrombolytic therapy. Adjusted late (more than 6 h, to hospital discharge) use of ASA and beta-blockers was 84 and 57%, respectively.

CONCLUSIONS

With the exception of thrombolytic therapy, proven efficacious medical therapies for AMI appear underused at the study hospital. Ongoing educational efforts and continuing patterns of practice analyses are needed.

Identification of novel genes, SYT and SSX, involved in the t(X;18)(p11.2;q11.2) translocation found in human synovial sarcoma

Human synovial sarcomas contain a recurrent and specific chromosomal translocation t(X;18)(p11.2;q11.2). By screening a synovial sarcoma cDNA library with a yeast artificial chromosome spanning the X chromosome breakpoint, we have identified a hybrid transcript that contains 5' sequences (designated SYT) mapping to chromosome 18 and 3' sequences (designated SSX) mapping to chromosome X. An SYT probe detected genomic rearrangements in 10/13 synovial sarcomas. Sequencing of cDNA clones shows that the normal SYT gene encodes a protein rich in glutamine, proline and glycine, and indicates that in synovial sarcoma rearrangement of the SYT gene results in the formation of an SYT-SSX fusion protein. Both SYT and SSX failed to exhibit significant homology to known gene sequences.

Identification of variability of ribosomal DNA spacer from Pseudomonas soil isolates

The polymerase chain reaction was used to amplify the spacer region located between the 16S and 23S ribosomal RNA genes of strains of Pseudomonas fluorescens and Pseudomonas putida isolated from peat bog, canola field, or arctic plants. Some of spacer region of four of the P. fluorescens strains examined, strains 64-3, 63-28, QP5, and R17-FP2, was about 515 base pairs (bp) in length, and contained the genes for tRNA(Ile) and tRNA(Ala). The DNA sequences of two strains from canola, 64-3 and 63-28, differed at only two positions. The sequences of the peat bog strains QP5 and R17-FP2 were identical. However, differences were noted between the DNA sequence common to the pair of strains 64-3 and 63-28 and the corresponding common sequence for strains QP5 and R17-FP2. These differences were mainly concentrated in two DNA segments of 10 and 19 bp, respectively. A probe for the 19-bp variable segment that occurs in the ribosomal spacer of strains QP5 and R17-FP2 recognized total DNA from these two strains, but not DNA from other bacteria of different origins. These results suggest the existence of a limited degree of variability within the 16S-23S ribosomal DNA spacer region, and that this variability may be useful to the recognition of particular Pseudomonas strains from environmental samples.

Abnormalities of the p53 MDM2 and DCC genes in human leiomyosarcomas

In this study we have screened a series of 29 primary leiomyosarcomas for abnormalities of both the p53 gene and the MDM2 gene, which encodes a p53-associated protein. SSCP (single-strand conformation polymorphism) analysis and direct sequencing of polymerase chain reaction (PCR)-amplified DNA were used to establish that 6/29 tumours possessed point mutations of the p53 gene. Using a monoclonal antibody that recognises the p53 protein in immunohistochemical staining experiments, we observed overexpression of the p53 protein in five of the six tumours containing point mutations in the p53 gene. Southern analysis of tumour DNA revealed that 2/29 tumours demonstrated amplification of the MDM2 gene. When considered together, these results indicate that alterations in both the p53 gene and MDM2 gene are important in the development of a significant minority of leiomyosarcomas. In addition, we have demonstrated a significant association between the presence of abnormalities of the p53 gene or MDM2 genes in leiomyosarcomas and a more advanced clinicopathological stage (P = 0.03). We have also examined the role of the DCC tumour-suppressor gene in the development of human soft-tissue tumours in a variety of histological types. Except for evidence of a rearrangement in a single leiomyosarcoma cell line, SK-UT-1, we have found no direct evidence to support a role for mutation of the gene in the development of human soft-tissue tumours.

The t(X;18)(p11.2;q11.2) translocation found in human synovial sarcomas involves two distinct loci on the X chromosome

A high proportion of synovial sarcomas contain the reciprocal translocation t(X;18)(p11.2;q11.2). We have previously localized the breakpoint on the X chromosome between the X chromosome marker DXS255 and an ornithine aminotransferase (OAT) pseudogene region designated OATL2. Subsequently by fluorescence in situ hybridization (FISH) we provided evidence that YACs corresponding to the OATL2 locus spanned the break-point. In order to confirm the position of this breakpoint cosmids corresponding to the OATL2 region were isolated. Most of these cosmids mapped to four cosmid contigs designated C1-C4. Analysis of two contigs, C1- and C4, using FISH established that in four of six synovial sarcomas examined the breakpoint occurs between these two contigs: C1 lies distal to the break-point while C4 is proximal. In contrast we provide evidence that the breakpoint in the remaining two tumours mapped to a second pseudogene region called OATL1 that is telomeric to the OATL2 locus. This heterogeneity of the breakpoint position on the X chromosome explains why in previous mapping studies there have been discrepancies between the results obtained by different laboratories.

Induction of osteopontin mRNA expression during activation of murine NK cells

Osteopontin (OPN) is an extracellular phosphorylated glycoprotein expressed in bone, kidney, nervous tissue, bone marrow, and granulated metrial gland (GMG) cells in murine decidua. We recently demonstrated that GMG cells are differentiated natural killer (NK) lineage cells that share phenotypic, functional, and morphologic characteristics with adherent interleukin-2 (IL-2)-activated NK cells. We now show that conditions that induce resting splenic NK cells to develop into adherent, activated cells induce the expression of opn mRNA. Nonstimulated NK cells did not express opn mRNA detectable by Northern analysis. However, expression was evident by day 1-2 of culture of NK cells with IL-2, increased to high levels by day 4, and was maintained at high levels thereafter. Thus, expression of mRNA for OPN, a secreted protein associated with cell adhesion, embryonic development, tissue remodeling, and immune regulation, is up-regulated during the activation of NK cells.

Hamster monoclonal antibodies to murine natural killer cells

To further the study of natural killer (NK) cells we have produced hamster monoclonal antibodies (MAbs) with reactivities to mouse NK cells. MAbs 4A2 and 3C2 were obtained by fusing spleen cells from Syrian hamsters immunized with IL-2-activated NK cells with Fox-NY myeloma cells. 4A2 antigen was expressed by bone marrow (BM)-derived IL-2-responsive NK cell precursors, by mature NK cells of the BM, and by a highly lytic subset of splenic NK cells, in addition to IL-2-activated NK cells. 3C2 antigen was also expressed by BM-derived NK cell precursors, by mature NK cells in the BM, at low levels by splenic NK cells, and at high levels by IL-2-activated NK cells. These MAbs are likely to provide useful reagents for the study of the life history and functional significance of NK cells.

Thrombolysis in acute myocardial infarction. The implementation of thrombolytic therapy in a coronary care unit in 1992

In order to describe the execution of thrombolytic therapy in acute myocardial infarction (AMI) in a coronary care unit, case records of 427 admissions in 1992 due to definite or possible AMI were reviewed: 32% received thrombolytic therapy while 68% did not because of contraindications, delayed admission, advanced age or nondiagnostic ECG changes. Among cases otherwise eligible for thrombolytic therapy according to the instructions of the department, 32% did not receive thrombolytic treatment solely because of nondiagnostic ECG changes. There is an obvious need for implementation of improved early diagnostic tools in the decision-making of thrombolysis as for instance newer, sensitive biochemical markers and continuous vectocardiography.

Home administration of intravenous antibiotics to children with cystic fibrosis

In examining the home administration of intravenous antibiotics to children with cystic fibrosis, this article concentrates on the role and responsibilities of the nurse in the support and education of the parents and children.

Help at hand for nurse placement

After reading about the problems encountered by Annette Millage in her quest to further her children's nurse training (Information exchange, October 7), I suggest that anybody in a similar position may obtain help by contacting the Nurse Teachers Group of the British Association of British Paediatric Nurses.

Is the cervical spine clear? Undetected cervical fractures diagnosed only at autopsy

Undetected cervical-spine injuries are a nemesis to both trauma surgeons and emergency physicians. Radiographic protocols have been developed to avoid missing cervical-spine fractures but are not fail-safe. Three case reports of occult cervical fractures documented at autopsy in the face of normal cervical-spine radiographs and computerized tomography scans are presented.