Regional mapping of the gene encoding dihydroorotate dehydrogenase,an enzyme involved in UMP synthesis,electron transport,and superoxide generation,to human chromosome region 16q22

De novo UMP synthesis is a critical metabolic pathway for nucleic acid synthesis and for a variety of metabolic pathways. The pathway is a target for many widely used cancer chemotherapy agents, several of which are pyrimidine analogs. Humans and cattle have been described with mutations in UMP synthesis that lead to serious inborn errors of metabolism. Dihydroorotate dehydrogenase (EC 1.3.3.1) (DHODH) carries out the fourth committed step in the pathway and may also be important for mitochondrial electron transport and oxygen radical metabolism. We report here that the gene encoding this enzyme in humans is located in the chromosomal region 16q22. With the mapping of DHODH, the mapping of all the steps of UMP synthesis is complete. All three genes involved map to different human chromosomes. This information is important in consideration of regulation of UMP synthesis in mammals, including humans.     

Effects of placental tissue on immunological responses

Using in vivo assays for alloreactivity, the responsiveness of maternal lymph node cells was shown to be increased when cells were harvested from both syngeneically and allogeneically pregnant mice. In addition, foetal liver and thymus cells induced a state of delayed type hypersensitivity to alloantigens whereas trophoblastic tissue, in the form of 12 to 15 day metrial glands, did not.

The influence of mouse placenta on in vitro immune responses was tested using 7-day ectoplacental cones as sources of trophoblastic tissue. Ectoplacental cones increased a T cell dependent but not a T cell independent antibody response, whereas T cell dependent cytotoxicity was reduced. The findings reported in this paper suggest that murine ectoplacental cones are a particularly useful tissue with which to study both specific and non-specific immunological activities of the trophoblast in syngeneic and allogeneic pregnancies.

     

Relationship of angiotensin-converting enzyme gene polymorphism to carotid wall thickness in middle-aged men

The insertion/deletion (I/D) polymorphism of the human angiotensin-converting enzyme (ACE) gene is a major determinant of circulating ACE levels. The D allele has been suggested to be a potent risk factor for coronary artery disease; however, the effect of the ACE gene on carotid atherosclerosis remains controversial. We therefore studied the relationship between the ACE gene I/D polymorphism and carotid artery intima-media thickness (IMT). A random sample of 300 men aged 50-59 years living in southern Finland were selected, and 233 agreed to participate (74%). Data were collected in 219 subjects. Quantitative B-mode ultrasonography was used to measure the maximum near and far wall IMT of right and left common, bifurcation, and internal carotid artery. The mean maximum IMT (overall mean) was calculated as the mean of 12 maximum IMTs at 12 standard sites. Patients with an IMT higher than 1.7 mm in at least one of 12 standard sites were assumed to have carotid atherosclerosis. The I/D polymorphism was determined by polymerase chain reaction. Overestimation of the frequency of the DD genotype was eliminated by insertion-specific primer and the inclusion of 5% dimethylsulfoxide. No significant differences were found in carotid wall thickness between the three genotypes; the overall mean IMT were 1.18 +/- 0.30, 1.22 +/- 0.24, and 1.08 +/- 0.40 mm in genotypes of II, ID, and DD, respectively. Similarly, the ACE genotypes and allele frequencies did not differ significantly between the subjects with and those without carotid atherosclerosis. There was no association in the subgroups among only nonsmoking subjects or subjects without chronic medication. The present data indicate that the I/D polymorphism of the ACE gene is not related to carotid IMT and is unlikely to play a major role in carotid atherosclerosis.     

Listening to patients' needs to improve their subjective quality of life

BACKGROUND: Subjective quality of life has gained a crucial role as a global measure of outcome in mental health care. This study aimed to investigate the impact of meeting needs for care, as assessed by both patients and mental health professionals, to improve the subjective quality of life in a sample of patients receiving community-based psychiatric care. METHOD: The study was conducted using a 4-year prospective longitudinal design. A cohort of patients from the South-Verona Community-based Mental Health Service (CMHS) was assessed at baseline and follow-up using, among other social and clinical measures, the Camberwell Assessment of Need (both staff and patient versions) and the Lancashire Quality of Life Profile. Predictors of changes of subjective quality of life were explored using block-stratified multiple regression procedures. RESULTS: Improvement in patients' clinical conditions as well as the reduction in patient-rated unmet needs in the social domain predicted an increase in subjective quality of life over 4 years; changes in staff-rated needs did not show any association with changes in subjective quality of life. CONCLUSIONS: Meeting self-perceived social needs, beyond symptoms reduction, seems to be of particular importance for ensuring a better quality of life for people with mental disorders. If the main goal of mental health care is to improve the quality of life of users, a policy of actively addressing patient-rated needs should be implemented.     

Dissociated effects of diazepam and lorazepam on short-latency afferent inhibition

Peripheral nerve inputs have an inhibitory effect on motor cortex excitability at short intervals (short-latency afferent inhibition, SAI). This can be tested by coupling electrical stimulation of peripheral nerve with transcranial magnetic stimulation (TMS) of the motor cortex. SAI is reduced by the anticholinergic drug scopolamine, and in patients with Alzheimer's disease. Therefore, it is possible that SAI is a marker of central cholinergic activity important for memory function. The benzodiazepine lorazepam also reduces SAI. Since benzodiazepines impair memory formation, but do not do so uniformly, with a maximum amnesic effect after lorazepam but less or no effect after diazepam, we were interested in testing in this non-behavioural study to what extent the effects of lorazepam and diazepam on circuits involved in SAI could be dissociated. In addition, and for control, we tested the effects of lorazepam and diazepam on short-interval intracortical inhibition (SICI), a motor cortical inhibition mediated through the GABA_A receptor. Lorazepam markedly reduced SAI, whereas diazepam slightly increased it. In contrast, both benzodiazepines uniformly increased SICI. Our findings demonstrate opposite effects of lorazepam and diazepam on SAI, an inhibition modulated by central cholinergic activity, but the same effects on SICI, a marker of neurotransmission through the GABA_A receptor. This dissociation suggests, for the first time, that TMS measures of cortical inhibition provide the opportunity to segregate differences of benzodiazepine action in human central nervous system circuits.     

Chemokine receptor CXCR4 expression in breast cancer as a potential predictive marker of isolated tumor cells in bone marrow

Interactions between the CXCR4 chemokine receptor in breast cancer cells and the ligand CXCL12/SDF-1α are thought to play an important role in breast cancer metastases. In this pilot study, CXCR4 expression along with other biomarkers including HER2-neu and EGFR, were measured in primary tumor samples of patients with operable breast cancer to test whether any of these biomarkers alone and in combination could indicate breast cancer with high likelihood of metastasizing to bone marrow. Cytokeratin (CK) positive cells in bone marrow were identified by flow-cytometry following enrichment with CK 7/8 antibody-coupled magnetic beads. Primary tumors (n = 18) were stained with specific antibodies for CXCR4, HER2-neu, EGFR, and PCNA using an indirect avidin–biotin horseradish peroxidase method. The majority of the patients had T2/T3 tumors (72%), or lymph node involvement (67%) as pathologic characteristics that were more indicative of high-risk breast cancer. High CXCR4 cytoplasmic expression was found in 7 of 18 patients (39%), whereas 6 of 18 patients (33%) were found to have CK positivity in bone marrow. The median number of CK⁺ cells was 236 (range, 20–847) per 5 × 10⁴ enriched BM cells. The presence of CK⁺ cells in bone marrow was found to be associated with increased expression of CXCR4 alone or in addition to EGFR and/or HER2-neu expression (P = 0.013, P = 0.005, and P = 0.025, respectively) in primary tumors. Furthermore, three patients with high CK positivity (>236 CK⁺ per 5 × 10⁴ enriched bone marrow cells) in bone marrow exclusively expressed high levels of CXCR4 with EGFR/HER2-neu (P = 0.001). Our data suggest that high CXCR4 expression in breast cancer may be a potential marker in predicting isolated tumor cells in bone marrow. CXCR4 coexpression with EGFR/HER2-neu might further predict a particular subset of patients with high CK positivity in bone marrow.     

Depressed type 1 cytokine synthesis by superantigen-activated CD4+ T cells of women with human papillomavirus-related high-grade squamous intraepithelial lesions

Carcinoma of the cervix is causally related to infection with the human papillomavirus (HPV), and T cells play a pivotal role in the immune response of the host to rid itself of HPV infection. Therefore, we assessed the T-cell function of women with HPV-related cervical neoplasia against a superantigen, Staphylococcus enterotoxin B (SEB). Each woman provided a cervical brush specimen for HPV DNA testing and Papanicolaou (Pap) smears for the staging of cervical lesions. They also provided a blood specimen for determination of the ability of CD4(+) T and CD8(+) T cells to synthesize Th1 (interleukin-2 [IL-2], gamma interferon [IFN-gamma], and tumor necrosis factor alpha [TNF-alpha]) and Th2 (IL-10) cytokines in response to activation with SEB. Compared with control subjects with self-attested negative Pap smears, women with high-grade squamous intraepithelial lesions (HSIL) had significantly lower percentages of activated CD4(+) T cells that produced IL-2 (P = 0.045), IFN-gamma (P = 0.040), and TNF-alpha (P = 0.015) and a significantly lower percentage of activated CD8(+) T cells that produced IL-2 (P < 0.01). These data indicate that women with HPV-related cervical HSIL show a decrease in Th1 cytokine production by activated CD4(+) T cells and suggested that compromised T-helper functions may negatively impact the function of cytotoxic CD8(+) T cells.     

Osteointegration of hydroxyapatite-coated and uncoated titanium screws in long-term ovariectomized sheep.

This study was designed to evaluate the osteointegration of HA-coated and uncoated titanium screws in the cortical bone of long-term (24 months) ovariectomized sheep (OVX group) compared to sham-aged sheep (Control group). At 12 weeks after implantation, the screws were tested biomechanically (extraction torque) and histomorphometrically (affinity index: AI) in both femoral and tibial diaphyses. Cancellous bone status was assessed by iliac crest biopsy. BMD of the L5 vertebra and a histomorphological study of the femoral and tibial shafts were performed to acquire data on cortical bone. A significant difference was found between the OVX and Control groups for BMD (p<0.0005), and a significant reduction in the cancellous bone area was observed in the OVX group. Femoral and tibial cortical bone parameters showed significant differences between the groups. The type of material selected (femurs: p<0.0005; tibiae: p<0.0005) and ovariectomy (femurs: p<0.005; tibiae: p<0.005) had a significant effect on the extraction torque. AI results were related to the presence or absence of ovariectomy (p<0.05) and strictly depended on the material implanted in the femur and tibia (p<0.0005). In conclusion, at implantation OVX sheep showed a significant loss of trabecular and cortical bone versus sham-aged sheep. The biomechanical and histomorphological results achieved suggest employing HA-coated screws in the presence of osteopenic cortical bone.     

The otter annotation system

With the completion of the human genome sequence and genome sequence available for other vertebrate genomes, the task of manual annotation at the large genome scale has become a priority. Possibly even more important, is the requirement to curate and improve this annotation in the light of future data. For this to be possible, there is a need for tools to access and manage the annotation. Ensembl provides an excellent means for storing gene structures, genome features, and sequence, but it does not support the extra textual data necessary for manual annotation. We have extended Ensembl to create the Otter manual annotation system. This comprises a relational database schema for storing the manual annotation data, an application-programming interface (API) to access it, an extensible markup language (XML) format to allow transfer of the data, and a server to allow multiuser/multimachine access to the data. We have also written a data-adaptor plugin for the Apollo Browser/Editor to enable it to utilize an Otter server. The otter database is currently used by the Vertebrate Genome Annotation (VEGA) site (http://vega.sanger.ac.uk), which provides access to manually curated human chromosomes. Support is also being developed for using the AceDB annotation editor, FMap, via a perl wrapper called Lace. The Human and Vertebrate Annotation (HAVANA) group annotators at the Sanger center are using this to annotate human chromosomes 1 and 20.     

XX true hermaphroditism in Southern African Blacks: Exclusion of SRY sequences and uniparental disomy of the X chromosome

A molecular investigation of 16 Bantu-speaking Black XX true hermaphrodites was undertaken in an attempt to determine the cause of the disorder. Y-specific sequences, including sequences mapping to the sexdetermining region of the Y, were shown to be absent from lymphocyte tissue of all 16 patients tested. Y chromosome sequences were also absent from the ovarian and testicular components of both ovotestes of a single XX true hermaphrodite, thus excluding gonadal mosaicism involving Y chromosome sequences. Since there is evidence for Xp genes involved in testis determination/differentiation, uniparental disomy of the X chromosome was investigated in 14 XXTH families. Uniparental disomy was excluded in 12 of the 14 families, and isodisomy was excluded in the remaining two cases. © 1995 Wiley-Liss, Inc.