The use of reaction time measures to evaluate nonword reading in primary progressive aphasia

We reported on a subject with nonfluent primary progressive aphasia (PPA), NL, who demonstrated an impaired ability to make rhyme judgments (Dowhaniuk, Dixon, Roy, Black, & Square, in press). Our hypothesis was that these deficits represent a precursor to phonological alexia. However, no definitive evidence supported the existence of a phonological reading impairment as NL made relatively few errors reading nonwords. To further evaluate NL's nonword reading, nonword and real word reaction times were compared. NL's reaction times were significantly longer for only nonwords compared to the slowest control subject. We then assessed the first two stages of processing involved in nonword reading (Coltheart, 1996). NL did not demonstrate deficits with graphemic parsing or phoneme assignment. His continuing problems with auditory rhyme judgments support the presence of a phonological processing deficit not specific to reading. We conclude that reaction time measures allow for the detection of subtle nonword reading deficits.

Characterization of the human and mouse HEY1, HEY2, and HEYL genes: cloning, mapping, and mutation screening of a new bHLH gene family

Many basic helix-loop-helix (bHLH) transcription factors are known as key regulators of embryonic development or differentiation in various species. We have isolated and characterized three new hairy-related bHLH transcription factor genes from mouse and human (hairy and Enhancer-of-split related with YRPW motif; HEY1, HEY2, and HEYL). All three HEY genes have a similar genomic structure with five exons. Together with a highly related Drosophila homologue, they form a new bHLH gene subfamily that is different from both hairy and the known vertebrate Hes and Her genes. While the overall structure with the bHLH domain, Orange domain, and WRPW motif is similar, the last motif is changed to KPYRPWG in Hey1/2 and absent in HeyL. This and other sequence features suggest Hey proteins to have unique functional properties. The genes were mapped by fluorescence in situ hybridization and RH mapping to the following human chromosomes: (HEY1) 8q21, (HEY2) 6q21, and (HEYL) 1p34.3. Based on expression patterns and map location, HEY genes are candidates for several human or mouse disease loci. However, initial screening of DNA from affected individuals for two human disorders and four mouse mutants did not reveal any diagnostic alterations in the coding regions.

Sex and relationships following childbirth: a first report from general practice of 131 couples

Changes in a couple's sexual relationship following childbirth may be more significant than previous studies have suggested. Around 50% of first-time parents in this study described their sex life as 'poor' or 'not very good' eight months after the birth of their baby, and one in five said that they would like help for this. First-time parents rating their general relationship as 'poor' or 'not very good' rose from 1% before pregnancy to 20% eight months after childbirth. Changes in the general relationship and the quality of sex life were associated in these couples.

Heterogeneity of Porphyromonas gingivalis strains in the induction of alveolar bone loss in mice

These experiments examine alveolar bone loss in a model in which specific pathogen-free mice are exposed orally with Porphyromonas gingivalis. Alveolar bone loss was induced as a result of a specific infection with P. gingivalis, rather than other environmental antigens. Infection with live P. gingivalis was required, as significant bone loss did not follow gavage with formalin-killed P. gingivalis. The virulence of different strains of P. gingivalis was compared. Two laboratory strains of the bacteria (ATCC 53977 and W50) and a mutant strain lacking the 43-kDa fimbrillin (strain DPG3) induced bone loss. P. gingivalis 381, however, did not induce bone loss. There was a strong immunoglobulin G (IgG) antibody response to infection with each strain but a significant serum IgA response only to strain 381. These studies show that in mice with a background oral microflora bone loss is induced by a specific infection with P. gingivalis and that bacterial strain variation is important in determining whether alveolar bone loss will ensue.

Molecular, genetic and physiological analysis of Cladosporium resistance gene function in tomato

Characterization of the DNA sequence of 4 tomato leaf mould disease resistance genes (Cf-2, Cf-4, Cf-5 and Cf-9) leads to the prediction that they encode C-terminally membrane anchored glycopeptides with many extracytoplasmic leucine rich repeats (LRRs). The N terminal LRRs are variable between the Cf-genes, suggesting a role in specificity, and the C terminal LRRs are more conserved, suggesting a role in signal transduction. Genetic analysis has revealed several Rcr genes that are required for Cf-gene function; their isolation will help us understand how Cf-genes work. Cf-9 confers responsiveness to pathogen-encoded Avr9 peptide on introduction to tobacco. Tobacco suspension cultures carrying the Cf-9 gene produce reactive oxygen species in response to Avr9 peptide, whereas untransformed cultures do not. The significance of these observations is discussed.

Iliac vascular injuries during elective laparoscopic surgery

Although it is extremely uncommon, iliac vascular injury is a serious complication of laparoscopic surgery. We performed a retrospective review of five patients who sustained injury to the iliac vessels during elective laparoscopic surgery. We reviewed the mechanism and location of injury for each case and examined ways in which such complications can be prevented. There were four women and one man; their mean age was 32 years. Three patients were undergoing laparoscopy at our institution, and two patients were transferred from outlying facilities soon after the injuries occurred. There were a total of seven iliac vascular injuries among our five patients. Three cases involved injury caused by the insufflation needle; the other two were injured by trocar introduction. Postoperative sequelae included decreased lower-extremity pulses in two patients and lower-extremity edema in three patients. The incidence of iliac vascular injury can be significantly reduced by proper insertion technique, the use of an open (Hasson) approach rather than the percutaneous insufflation needle, and a thorough knowledge of the vascular anatomy in the pelvic region.

Choice of management strategy for colorectal cancer based on a diagnostic immunohistochemical test for defective mismatch repair

BACKGROUND

Despite intensive research into the molecular abnormalities associated with colorectal cancer (CRC), no diagnostic tests have emerged which usefully complement standard histopathological assessments.

AIMS

To assess the feasibility of using immunohistochemistry to detect replication error (RER) positive CRCs and determine the incidence of RER positivity within distinct patient subgroups.

METHODS

502 CRCs were analysed for RER positivity (at least two markers affected) and/or expression of hMSH2 and hMLH1.

RESULTS

There were 15/30 (50%) patients with metachronous CRCs, 16/51 (31%) with synchronous CRCs, 14/45 (31%) with a proximal colon carcinoma, and 4/23 (17%) who developed a CRC under the age of 50 showed RER positivity. However, 0/54 patients who developed a solitary carcinoma of the rectum/left colon over the age of 50 showed RER positivity. Immunohistochemical analysis revealed that 66/66 (100%) RER positive carcinomas were associated with complete lack of expression of either hMSH2 or hMLH1. This correlation was confirmed using a further 101 proximal colon carcinomas. Patients with a mismatch repair defective carcinoma showed improved survival but a 5.54 times relative risk of developing a metachronous CRC. A prospective immunohistochemical study revealed 13/117 (11%) patients had a mismatch repair defective carcinoma. A fivefold excess of hMLH1 defective cases was noted.

CONCLUSIONS

All RER positive carcinomas were identified by the immunohistochemical test. This is the first simple laboratory test which can be performed routinely on all CRCs. It will provide a method for selecting patients who should be investigated for HNPCC, offered long term follow up, and who may not respond to standard chemotherapy regimens.

Serum antibody response to oral infection precedes but does not prevent Porphyromonas gingivalis-induced alveolar bone loss in mice

The purpose of this study was to determine whether humoral immunity prevents bacterially induced alveolar bone loss. BALB/cByJ mice were orally infected with the human periodontopathic bacterium Porphyromonas gingivalis, and were compared with sham-infected mice. Specific serum antibody titers to P. gingivalis were measured by enzyme-linked immunosorbent assay. Alveolar bone levels were measured as the distance from the cementoenamel junction to the alveolar bone crest and bone loss was defined as a change in bone levels over time or between infected and sham-infected animals. The specific humoral response was predominantly of the IgG isotype, although low levels of specific serum IgA were also present. Antibody titers in the infected animals were significantly different from those in the sham-infected animals by 18 days and remained at maximal levels at 47 days. Bone loss became significant by 26 days and continued to progress at 47 days. Thus the serum antibody response to oral infection with P. gingivalis preceded detectable bone loss and remained elevated while bone loss increased. The presence of specific antibody did not prevent the onset or progression of bone loss.

CD4(+) T cells and the proinflammatory cytokines gamma interferon and interleukin-6 contribute to alveolar bone loss in mice

In this study, we used a mouse model to examine the role of the adaptive immune response in alveolar bone loss induced by oral infection with the human gram-negative anaerobic bacterium Porphyromonas gingivalis. Severe combined immunodeficient mice, which lack B and T lymphocytes, exhibited considerably less bone loss than did immunocompetent mice after oral infection, suggesting that lymphocytes contribute to this process. Bone loss after oral infection was decreased in mice deficient in major histocompatibility complex (MHC) class II-responsive CD4(+) T cells, but no change in bone loss was observed in mice deficient in MHC class I-responsive CD8(+) T cells or NK1(+) T cells. Mice lacking the cytokine gamma interferon or interleukin-6 also demonstrated decreased bone loss. These results suggest that the adaptive immune response, and in particular CD4(+) T cells and the proinflammatory cytokines that they secrete, are important effectors of bone loss consequent to P. gingivalis oral infection. The studies also reinforce the utility of the mouse oral infection model in dissecting the pathobiology of periodontal disease.

Inhibition of rat hepatocyte proliferation by transforming growth factor beta and glucagon is associated with inhibition of ERK2 and p70 S6 kinase

Stimulation of hepatocyte proliferation by epidermal growth factor (EGF) and insulin is inhibited by transforming growth factor beta (TGF-beta) and by glucagon. It is also suppressed by inhibitors of various protein kinases, including rapamycin, which blocks activation of p70 S6 kinase (p70(S6k)), PD98059, which inhibits the activation of extracellular-regulated kinase (ERK), and SB 203580, an inhibitor of the p38 mitogen-activated protein kinase (p38 MAPK). In this study, we investigated whether the inhibition of proliferation by TGF-beta involves these protein kinase cascades. Culture of hepatocytes with TGF-beta for 16 hours decreased the stimulation by EGF of ERK2 and p70(S6k) (by 50% and 35%, respectively), but did not affect the stimulation of either p38 MAPK, c-jun NH2-terminal kinase (JNK), or protein kinase B (PKB). Culture of hepatocytes with glucagon for 16 hours also inhibited the stimulation by EGF of activation of ERK2 and p70(S6k) (by approximately 50%). The inhibitory effects of glucagon were observed when the hormone was added either 10 minutes or 60 minutes before EGF addition, whereas no effects of TGF-beta were observed after 10-minute or 60-minute incubation. These results suggest that the inhibition of hepatocyte proliferation by TGF-beta may be in part mediated by inhibition of ERK2 and p70(S6k), but does not involve PKB, JNK, or p38 MAPK. Unlike glucagon, the effects of TGF-beta are not elicited in response to short-term treatment.

Inferring sublexical correspondences from sight vocabulary: evidence from 6- and 7-year-olds

We report an experiment designed to investigate 6-to-7-year-old children's ability to acquire knowledge of sublexical correspondences between print and sound from their reading experience. A computer database containing the printed word vocabulary of children taking part in the experiment was compiled and used to devise stimuli controlled for grapheme-phoneme correspondence (GPC) frequency and rime neighbourhood consistency according to the children's reading experience. Knowledge of GPC rules and rime units was compared by asking children to read aloud three types of nonword varying in regularity of GPC and consistency of rime pronunciation. Results supported the view that children can acquire knowledge of both GPC rules and rime units from their reading experience. GPC rule strength affects the likelihood of a GPC response; rime consistency affects the likelihood of a rime response.

Doctors as managers

In order that a hospital function efficiently, it is imperative that the management use its skills to best effect. On this subject, Dr Dixon discusses 'organizational bonding', a bonding which, among other things, will improve planning, budgetary control and quality control and speed up decision-making, by means of decentralization. '... the vertical divisions between different professional groups and hierarchies', she concludes, 'have to be replaced by horizontally integrated service units.'

Distribution of neuregulin-1 (nrg1) and erbB4 transcripts in embryonic chick hindbrain

Interrhombomeric signalling has a role in development of the chick hindbrain. We have examined the transcript distributions of neuregulin-1 (nrg1), a signalling molecule with effects on nervous system development, and of one of its receptors, erbB4. Expression patterns of these two molecules are, in contrast to the situation in mouse, not consistent with a role in interrhombomeric signalling, but are consistent with a role in signalling between dorsal and ventral territories within individual rhombomeres. Other areas of potential nrg1-erbB4 signalling are the cerebellum, the caudal rhombic lip, and dorsolateral mantle in the caudal hindbrain. nrg1 is additionally expressed in motor neurons and erbB4 in rostral rhombic lip plus a subset of rhombic lip derivatives. Both molecules are also expressed in other parts of the nervous system and in nonneuronal tissue. The expression data presented will facilitate interpretation of future functional studies on nrg1-erbB4 signalling during hindbrain development.

Frequent allelic loss and homozygous deletion in chromosome band 8p23 in oral cancer

Frequent loss of heterozygosity on chromosome 8p in a variety of human malignancies, including head and neck cancers, has suggested the presence of a tumor suppressor gene (or genes) associated with the pathogenesis of these cancers. To test the role of genetic alterations at 8p23 in oral carcinogenesis, we studied 51 squamous cell carcinomas of the head and neck and 29 oral squamous cell carcinoma cell lines for allelic loss using 7 microsatellite markers spanning approximately 5 cM of chromosome band 8p23. Twenty-three of 51 tumors (45%) and 23 of 29 cell lines (79%) showed allelic loss at 1 or more loci. Three cell lines showed homozygous deletion of loci within a 3 cM region defined by the markers D8S1781 and D8S262. Our results suggest that a tumor suppressor gene (or genes) is located in 8p23 and is associated with the development and/or progression of oral carcinomas.

EYA4, a novel vertebrate gene related to Drosophila eyes absent

We have isolated a family of four vertebrate genes homologous to eyes absent (eya), a key regulator of ocular development in Drosophila. Here we present the detailed characterization of the EYA4 gene in human and mouse. EYA4 encodes a 640 amino acid protein containing a highly conserved C-terminal domain of 271 amino acids which in Drosophila eya is known to mediate developmentally important protein-protein interactions. Human EYA4 maps to 6q23 and mouse Eya4 maps to the predicted homology region near the centromere of chromosome 10. In the developing mouse embryo, Eya4 is expressed primarily in the craniofacial mesenchyme, the dermamyotome and the limb. On the basis of map position and expression pattern, EYA4 is a candidate for oculo-dento-digital (ODD) syndrome, but no EYA4 mutations were found in a panel of ODD patients.

Trauma deaths in a rural area

This study was undertaken in order to clarify the causes of death amongst rural trauma victims in Union County, Arkansas. Over a five-year time interval, seventy-two percent (n = 60) of the trauma deaths occurred at the geographical site of injury before the arrival of any emergency medical services. Thus, prolonged time to discovery of trauma victims accounts for the most significant factor leading to trauma deaths in Union County. Education regarding injury prevention must continue to be emphasized to the public.