Will Rogers revisited: prospective observational study of survival of 3592 patients with colorectal cancer according to number of nodes examined by pathologists

To investigate the relationship between survival in colorectal cancer patients and the number of lymph nodes examined by a pathologist, previously attributed to stage migration, we used data from a cohort of 5174 colorectal cancer patients recruited between September 1991 and August 1994, and followed-up for 5 years. We selected cases with data present on all prognostic variables, and stratified them into three groups by number of nodes examined. We made a multivariate survival comparison using a Cox regression model. In all, there were 3592 cases with data present on all prognostic variables. Patients who had >10 nodes identified had a significant survival advantage over those who had 5–10 identified, who had in turn a similar advantage over those with 0–4 identified (P<0.001). This effect was present in the whole group and at all Dukes' stages, although statistically significant only in stages B (P=0.004) and C (P=0.019). The effect remained after adjustment in a Cox regression model in which the mean number of nodes taken out by each surgical firm did not predict survival. In a sub-group with data on lymphocytic infiltration into the primary tumour a survival advantage was noted in those with prominent rather than mild infiltration (P<0.001): the former also tended to have more nodes found (P=0.015). Stage migration alone cannot explain these results, as survival advantages are noted across the whole population independent of stage. Lymphocytic infiltration into the primary tumour is prognostically important, and is associated with the number of nodes found. Reactive enlargement of lymph nodes in the mesentery may make them easier to find, reflect immune response to the tumour, and thus indirectly impact upon survival.

Change in lean body mass is a major determinant of change in areal bone mineral density of the proximal femur: a 12-year observational study

Our objective was to assess the contribution of lean body mass (LBM) and fat body mass (FBM) to areal bone mineral density (aBMD) in women during the years surrounding menopause. We used a 12-year observational design. Participants included 75 Caucasian women who were premenopausal, 53 of whom were available for follow-up. There were two measurement periods: baseline and 12-year follow-up. At both measurement periods, bone mineral content and aBMD of the proximal femur, posterior-anterior lumbar spine, and total body was assessed using dual-energy X-ray absorptiometry (DXA). LBM and FBM were derived from the total-body scans. General health, including current menopausal status, hormone replace therapy use, medication use, and physical activity, was assessed by questionnaires. At the end of the study, 44% of the women were postmenopausal. After controlling for baseline aBMD, current menopausal status, and current hormone replacement therapy, we found that change in LBM was independently associated with change in aBMD of the proximal femur (P = 0.001). The cross-sectional analyses also indicated that LBM was a significant determinant of aBMD of all three DXA-scanned sites at both baseline and follow-up. These novel longitudinal data highlight the important contribution of LBM to the maintenance of proximal femur bone mass at a key time in women's life span, the years surrounding menopause.

Adoption of Security Systems By Dairy Farms to Address Bioterrorist Threats in the Intermountain United States

Data generated from a survey of western dairy farms was used to determine the characteristics of dairy farmers who have undertaken to improve security measures on their farms during the past 2 or 3 yr. The findings suggest that decisions to improve on-farm security are influenced by the producer's awareness of how to develop a security policy, and by the size of the dairy operation. The results also support the notion that farms may be vulnerable to bioterrorist attacks because most farmers do not believe it is important to establish on-farm security policies.

Comparison of a camera-software system and typical farm management for detecting oestrus in dairy cattle at pasture

AIM

To compare the sensitivity, specificity, predictive values and accuracy of detection of oestrus using a novel oestrus detection strip (ODS) and a camera-software device (CSD) with typical farm management practices of visual observation and use of tail paint in dairy cattle at pasture.

METHODS

Dairy cows (n = 480) in a seasonal-calving herd managed at pasture under typical commercial conditions in New Zealand were stratified by age, body condition score and days in milk, then randomly allocated to one of two groups prior to the planned start of mating (PSM). Tail paint was applied to all cows and oestrus detected by visual observation of oestrous behaviour and removal of paint, by farm staff. One group (n = 240) was fitted with ODS and also monitored for signs of oestrus using a CSD, while the Control group (n = 240) was monitored using tail paint and visual observations only. Cows detected in oestrus were artificially inseminated (AI), and pregnancy status determined using rectal palpation and ultrasonography, 51-52 days after the end of a 55-day A period. Results of pregnancy diagnosis were used to confirm the occurrence of oestrus, and the sensitivity, specificity, predictive value and accuracy of detection of oestrus compared between oestrus detection methods.

RESULTS

The sensitivity and accuracy of oestrus detection in the Control group, using visual observation and tail paint, were low. Compared with the Control group, detection of oestrus using the ODS and CSD resulted in greater sensitivity (85% vs 78%; p = 0.006), specificity (99.6% vs 98.0%; p < 0.001), positive predictive value (PPV; 88% vs 51%; p < 0.001) and overall accuracy (99.0% vs 98.0%; p < 0.001). Negative predictive value (NPV) did not differ significantly between groups (99.4% vs 99.3%; p = 0.28). Pregnancy rate to first service was higher in the CSD group than in the Control group (72% vs 39%; p < 0.05). Use of the CSD significantly increased the cumulative proportion of cows pregnant to AI over the breeding period (p = 0.044).

CONCLUSION AND CLINICAL RELEVANCE

The ODS and CSD was satisfactory for detection of oestrus in seasonal calving dairy herds grazing on pasture and could improve the sensitivity and accuracy of detection of oestrus in herds where these are low.

Immunoglobulin and T-cell receptor gene rearrangement in Castleman's disease: molecular genetic analysis

AIMS

Castleman's disease (CD) is a rare heterogeneous disorder that is associated with an increased risk of developing lymphoma. Whether CD is primarily hyperplastic or neoplastic in origin is not yet clear. The aim of this study was to investigate CD further by determining the clonality status of its lymphocyte populations.

METHODS AND RESULTS

We reviewed 20 patients with CD, 15 with the hyaline-vascular type and five with the plasma cell type. Immunoglobulin (JH) and T-cell receptor (TCR) gene rearrangements were examined using polymerase chain reaction and Southern blotting techniques. B-lymphocyte clonality was also assessed by flow cytometry (FC) and by immunohistochemistry (IHC). The age range of the patients was 15-66 years: nine female and 11 male. Monoclonal rearrangement of the immunoglobulin (JH) gene was detected in only one case. No cases were positive for monoclonal rearrangement of the TCR gene. All of the cases except one were negative for immunoglobulin light chain restriction by both FC and IHC.

CONCLUSIONS

The lymphoid cells in CD are most commonly polyclonal in origin, which supports a non-neoplastic origin. However, rare cases may show lymphocyte monoclonality, which could represent the development of a neoplastic population. The latter cases should be followed closely.

Effect of process standards on survival of patients with head and neck cancer in the south and west of England

The aim of the study was to compare standards for the process of care and 2-year survival between two cohorts of patients with head and neck cancer in the south and west of England. A total of 566 and 727 patients presented in 1996–97 and 1999–2000, respectively. The median number of cases treated per surgeon was 4 (1997, range 1–26) and 4 (2000, 1–23) and per radiotherapist was 10 (1–51) and 19 (1–70). For all ‘nontemporal’ standards, the overall standard increased, without reaching minimum high targets, while most ‘waiting times’ increased. Overall 2-year survival was 64.1% in 1997 and 65.1% in 2000. There was no difference in survival between networks (range 56–68, 1997, log-rank test 4.1, P=0.4; 62–69, 2000, log-rank test 1.26, P=0.69). Patients assessed by a multidisciplinary clinic exhibited improved survival (1997: P=0.1; 2000: hazard ratio 0.7, P=0.02), as did those with a pretreatment chest X-ray (hazard ratio 0.7, P=0.03). Despite an increased incidence, standards for the process of care for patients with head and neck cancer improved between 1996 and 2000, while waiting times increased and 2-year survival rates remained unaltered. Two out of five networks demonstrated centralisation of services between audits. Being seen in a multidisciplinary clinic correlated strongly with patient survival.

The quantitative assessment of photodensity of the third carpal bone in the horse

AIM

To determine whether variation in x-ray-beam angle significantly affected photodensity of the third carpal bone (C3) in the horse using the tangential radiographic view, and indirectly determine whether radioabsorptiometry (RA) could be used to assess differences in bone mineral density (BMD) of C3 between exercised and non-exercised horses.

METHODS

The left distal carpal row was isolated post-mortem from 2-year-old Thoroughbred horses that had been either exercised (n=7) for up to 14 weeks using a standard training regimen for racehorses, or not exercised (n=7). The effect of variation in x-ray-beam angle on photodensity was determined on these isolated carpal bones in vitro. Image analysis was used to assess photodensity (compared to a known thickness of aluminium) of four regions of interest (ROI) in C3 and one ROI in the fourth carpal bone (C4) of 14 isolated distal rows of carpal bones of the horse. The isolated carpal bones were placed fl at on a x-ray cassette and radiographed at 90 degrees (i.e. with the x-ray beam perpendicular to the cassette). The x-ray-beam angle was varied in the dorsal sagittal plane by 5 degrees increments to a total of 15 degrees from 90 degrees and from a base angle of 60 degrees (the x-ray-beam angle at which the tangential view is taken in clinical cases).

RESULTS

Variation in beam angle of <10 degrees from 90 degrees significantly affected photodensity, and photodensity was significantly affected when the angle was varied <5 degrees from 60 degrees . When taken at an x-ray-beam angle of 60 degrees , the abaxial aspect of the radial facet of C3 had a consistently higher photodensity than the rest of C3 and C4. The photodensity of the third and fourth carpal bones was higher in exercised horses than in non-exercised horses.

CONCLUSION

As variation in x-ray-beam angle significantly affected photodensity, RA using the tangential view is not considered clinically applicable for assessing BMD of C3 and the accuracy of subjective assessment of BMD of C3 using the tangential view in horses is questionable.

The binding interface database (BID): a compilation of amino acid hot spots in protein interfaces

SUMMARY

To make information about protein interactive function easily accessible, we are mining the primary scientific literature for detailed data about protein interfaces. The Binding Interface Database (BID) organizes the vast amount of protein interaction information into tables, graphical contact maps and descriptive functional profiles. Currently data on 170 interacting protein pairs are available with over 1300 mutations described.

AVAILABILITY

The BID database is freely available at http://tsailab.org/BID/ To have your protein of interest entered, contact Tiffany Fischer (tiffbrink@neo.tamu.edu) or Jerry Tsai at the email below

Site-specific molecular design and its relevance to pharmacogenomics and chemical biology

The emergence of the new discipline of pharmacogenomics reflects the growing convergence of chemical and genomic space. The massive information-driven growth in both computational chemistry and structural biology is leading to unprecedented opportunities in both chemical and biological design. In this paper we relate current opinion in structural biology to recent developments in computational drug design. Sequence information now permits protein structure prediction and, together with experimental protein structure determination, a complete database of ligand-binding sites and protein-protein interactions can be assembled. When aligned with site exploration and virtual screening, this information provides a foundation for structure-based pharmacogenomics. In association with chemical genomics, structure-based design will allow major new insights into a compound's biological and pharmaceutical properties.

Metastatic neuroendocrine tumor presenting as spinal cord compression--a case report and brief comment

Gastrointestinal neuroendocrine tumors are derived from the diffuse neuroendocrine system of the gastrointestinal tract which is composed of amine and acid producing cells with different hormonal profiles, depending on the site of origin. The tumors they produce can be divided into carcinoid tumors and pancreatic endocrine tumors. We believe this to be only the fourth case in the literature of a patient presenting with cord compression as a result of a metastatic neuroendocrine tumor (MEDLINE 1966-2000).

Structural analysis of the polysaccharide from the lipopolysaccharide of Porphyromonas gingivalis strain W50

The lipopolysaccharide (LPS) of Porphyromonas gingivalis is an important pro-inflammatory molecule in periodontal disease and a significant target of the host's specific immune response. In addition, we recently demonstrated using monoclonal antibodies that the Arg-gingipains of P. gingivalis are post-translationally modified with glycan chains that are immunologically related to an LPS preparation from this organism. In the present investigation, we determined the structure of the O-polysaccharide of P. gingivalis W50 that was fully characterized on the basis of 1D and 2D NMR (DQF-COSY, TOCSY, NOESY, ROESY, 1H-13C HSQC and 1H-31P HXTOCSY) and GC-MS data. These data allowed us to conclude that the O-polysaccharide is built up of the tetrasaccharide repeating sequence: -->6)-alpha-D-Glcp-(1-->4)-alpha-L-Rhap-(1-->3)-beta-D-GalNAc-(1-->3)-alpha-D-Galp-(1--> and carries a monophosphoethanolamine residue at position C-2 of the alpha-rhamnose residue in a nonstoichiometric (approximately 60%) amount. These data indicate that the O-polysaccharide of P. gingivalis LPS is composed of an unusually modified tetrasaccharide repeating unit.

Triterpenoid saponins from Acacia victoriae (Bentham) decrease tumor cell proliferation and induce apoptosis

This report describes the isolation and partial purification of novel triterpenoid saponins [Fraction 35 (F035)] and two pure biologically active derivatives (termed avicins D and G) from Acacia victoriae, an Australian desert tree of the Leguminosae family. F035 and the avicins markedly inhibited the growth of several tumor cell lines with minimum growth inhibition in human foreskin fibroblasts, mouse fibroblasts, and immortalized breast epithelial cells at similar concentrations. F035 and the avicins induced cell cycle (G1) arrest of the human MDA-MB-453 breast cancer cell line and apoptosis of the Jurkat (T-cell leukemia) and the MDA-MB-435 breast cancer cell line. The triterpenoid saponins also partially inhibited phosphatidylinositol 3-kinase activity in Jurkat T cells in a time-dependent manner and phosphorylation in the downstream protein Akt, whereas no affect was seen on the Ras/mitogen-activated protein kinase cascade. These observations as well as other work from our laboratory demonstrating mitochondrial perturbation, chemoprevention, and inhibition of nuclear factor kappaB suggest that triterpenoid saponins from A. victoriae have potential as novel anticancer agents. Recent work linking Akt signaling with glucose metabolism, stress resistance, and longevity suggests other potential applications of these compounds.

Models of acculturation and health behaviors among Latino immigrants to the US

A basic premise of much of the health research conducted with immigrant groups is that culturally based behaviors change over time as a result of acculturation, i.e., interaction with the mainstream US culture. However, models of acculturation have not taken into account how group-specific characteristics and the varying social and political contexts immigrant groups face may impact the acculturation process. In this study of 150 families, we examined the inter-relationship of indicators of acculturation among two Latino groups to discern the impact of gender and country of origin on the relationship between variables. Results indicated that increased years of residence in the United States had the predictable impact of increased competence in English and increased use of English, but had differing impact by country of origin on the cultural orientation of the respondents' environment and on ethnic identification. Also, gender was associated with differing levels of English language use and with perceived social acceptance, such that males used more English and reported less social acceptance than females. Loading separately from the language and cultural behavior variables, this factor, perceived social acceptance, merits research as a predictor of service use given that respondents understood non-acceptance as resulting from being identified as Latino. not from behaving differently from the mainstream. The differing patterns of association by country of origin and by gender and the measurement issues these raise, highlight the importance of specifying more complex models of a cculturation than is done typically in research with Latinos.

Avicins: triterpenoid saponins from Acacia victoriae (Bentham) induce apoptosis by mitochondrial perturbation

Anticancer agents target various subcellular components and trigger apoptosis in chemosensitive cells. We have recently reported the tumor cell growth inhibitory properties of a mixture of triterpenoid saponins obtained from an Australian desert tree (Leguminosae) Acacia victoriae (Bentham). Here we report the purification of this mixture into two biologically pure components called avicins that contain an acacic acid core with two acyclic monoterpene units connected by a quinovose sugar. We demonstrate that the mixture of triterpenoid saponins and avicins induce apoptosis in the Jurkat human T cell line by affecting the mitochondrial function. Avicin G induced cytochrome c release within 30-120 min in whole cells and within a minute in the cell-free system. Caspase inhibitors DEVD or zVAD-fmk had no effect on cytochrome c release, suggesting the direct action of avicin G on the mitochondria. Activation of caspase-3 and total cleavage of poly(ADP-ribose) polymerase (PARP) occurred between 2 and 6 h posttreatment with avicins by zVAD-fmk. Interestingly, in the treated cells no significant changes in the membrane potential preceded or accompanied cytochrome c release. A small decrease in the generation of reactive oxygen species (ROS) was measured. The study of these evolutionarily ancient compounds may represent an interesting paradigm for the application of chemical ecology and chemical biology to human health.

Power output of legs during high intensity cycle ergometry: influence of hand grip

Traditionally, leg cycle ergometry is used to assess the power output of the lower limbs. However, it is suspected that the upper body makes a significant, albeit as yet unknown, contribution to the measured power output, and as such, the lean mass of the whole body should be considered during ergometric assessment. To test this idea, indices of mechanical power output were obtained from 11 subjects during high intensity leg cycle ergometry tests (20 second duration; 75 grams per kilogram total body mass) using two protocols: one with a standard handle-bar grip (with grip) and one with supinated wrists (without-grip). Peak mechanical power, mean mechanical power, fatigue index and total mechanical work values were calculated for each subject during each test and the sample mean differences associated with the two protocols were compared using paired Student t-tests. The with-grip protocol yielded significantly greater peak mechanical power output than the without-grip protocol (886+/-124 W and 815+/-151 W, respectively), suggesting a significant upper body contribution to the maximum power output measured for the legs. As a first step towards quantifying the upper body involvement during leg cycle ergometry, surface electromyography of the forearm musculature was measured in a twelfth subject whilst performing each of the test protocols. During the with-grip ergometer tests, the intensity of electrical activity in the forearm musculature was similar, if not greater than, the intensity of electrical activity recorded for the forearm musculature during 100% maximum voluntary hand grip-dynamometer contractions, suggesting maximum isometric-type forearm muscle contraction during the with-grip leg ergometry tests. These findings suggest that the performance of traditional-style leg cycle ergometry requires a muscular contribution from the whole body. As such, researchers should be mindful of this, both in terms of the allocation of ergometer loads, and in the analysis of blood-borne metabolites.

Glycosylation of immunoglobulin light chains associated with amyloidosis

AL amyloidosis is a fatal disease caused by deposition of immunoglobulin light chains in a fibrillarforin (AL) in various organs. By searching the Kabat database of immunoglobulin sequences using the KabatMan software, we have shown that there is a preponderance of the consensus glycosylation sequon (AsnXxxSer/Thr) in the framework regions of amyloid light chains. We have characterised by computer graphics simulations, NMR spectroscopy and carbohydrate biochemistry the structure and conformation of the oligosaccharide from amyloid protein AL MS (lamba1) and from the amyloid associated Bence Jones protein of patient MH (kappa1). These proteins have glycosylation in the hypervariable complementarity-determining region versus framework region, respectively. Both contained a 2-6 sialylated core fucosylated biantennary chain mostly with bisecting GIcNAc. Together our results suggest that light chain glycosylation may be one of several modifications which may render the protein more prone to amyloid formation.

Fetal alcohol syndrome (FAS) primary prevention through fas diagnosis: II. A comprehensive profile of 80 birth mothers of children with FAS

A 5-year, fetal alcohol syndrome (FAS) primary prevention study was conducted in Washington State to: (1) assess the feasibility of using a FAS diagnostic and prevention clinic as a centre for identifying and targeting primary prevention intervention to high-risk women; (2) generate a comprehensive, lifetime profile of these women; (3) identify factors that have enhanced and/or hindered their ability to achieve abstinence. The results of this study are presented in two parts. Objective 1 is summarized in the preceding paper and objectives 2 and 3 are summarized here. Comprehensive interviews were conducted with 80 women, who had given birth to a child diagnosed with FAS, to document their sociodemographics, reproductive and family planning history, social and healthcare utilization patterns, adverse social experiences, social support network, alcohol use and treatment history, mental health, and intelligence quotient (IQ). These high-risk women were diverse in racial, educational and economic backgrounds, were often victims of abuse, and challenged by mental health issues. Despite their rather harsh psychosocial profile, many demonstrated the ability to overcome their alcohol dependence over time. Relative to the women who had not achieved abstinence, the women who had achieved abstinence had significantly higher IQs, higher household incomes, larger more satisfactory social support networks, were more likely to report a religious affiliation, and were more likely to be receiving mental health treatment for their mental health disorders. The rate of unintended pregnancies and alcohol-exposed pregnancies was substantial. Key barriers to achieving effective family planning were maternal alcohol and drug use, lack of access to birth control and lack of support by their partner to use birth control. A FAS diagnostic and prevention clinic can be used to identify women at high risk for producing children damaged by prenatal alcohol exposure. Primary prevention programmes targeted to this population could lead to measurable reductions in the incidence of FAS.

Fetal alcohol syndrome (FAS) primary prevention through FAS diagnosis: I. Identification of high-risk birth mothers through the diagnosis of their children

A 5-year, fetal alcohol syndrome (FAS) primary prevention study was conducted in Washington State to: (1) assess the feasibility of using a FAS diagnostic and prevention clinic as a centre for identifying and targeting primary prevention intervention to high-risk women (namely women who had given birth to a child with FAS); (2) generate a comprehensive, lifetime profile of these women; (3) identify factors that have enhanced and/or hindered their ability to achieve abstinence. The results of this study are presented in two parts: work on objective 1 is summarized in the present paper; whereas that on objectives 2 and 3 is summarized in the accompanying paper. This project demonstrated that a multidisciplinary FAS Diagnostic and Prevention Network (FAS DPN) clinic could successfully attract and meet the diagnostic and treatment planning needs of patients presenting with prenatal alcohol exposure. One out of every three patients evaluated in the FAS DPN clinics was diagnosed with FAS or static encephalopathy/alcohol exposed. The birth mothers of one out of every three of these children diagnosed with FAS or static encephalopathy/alcohol exposed could be located and directly contacted. Half of the birth mothers directly contacted were still at risk for producing more children damaged by prenatal alcohol exposure. Thus, one out of every 18 children evaluated in the FAS DPN clinics had a birth mother who could be found and was at risk of producing more children damaged by prenatal alcohol exposure. Primary prevention programmes targeted to this high-risk population could lead to measurable, cost-effective reductions in the incidence of FAS. Using this approach, the cost of raising a child with FAS would be roughly 30 times the cost of preventing FAS in the child. The benefit to the children, their mothers, and society would be immeasurable.

Real-time transmission of full-motion echocardiography over a high-speed data network: impact of data rate and network quality of service

With high-resolution network transmission required for telemedicine, education, and guided-image acquisition, the impact of errors and transmission rates on image quality needs evaluation.

METHODS

We transmitted clinical echocardiograms from 2 National Aeronautics and Space Administration (NASA) research centers with the use of Motion Picture Expert Group-2 (MPEG-2) encoding and asynchronous transmission mode (ATM) network protocol over the NASA Research and Education Network. Data rates and network quality (cell losses [CLR], errors [CER], and delay variability [CVD]) were altered and image quality was judged.

RESULTS

At speeds of 3 to 5 megabits per second (Mbps), digital images were superior to those on videotape; at 2 Mbps, images were equivalent. Increasing CLR caused occasional, brief pauses. Extreme CER and CDV increases still yielded high-quality images.

CONCLUSIONS

Real-time echocardiographic acquisition, guidance, and transmission is feasible with the use of MPEG-2 and ATM with broadcast quality seen above 3 Mbps, even with severe network quality degradation. These techniques can be applied to telemedicine and used for planned echocardiography aboard the International Space Station.

Performance and standards for the process of head and neck cancer care: South and West audit of head and neck cancer 1996-1997 (SWAHN I). South and West Regional Cancer Organisation Tumour Panel for Head and Neck Cancer

Evidence suggests wide variation in cancer care between different hospitals in the UK. To establish bench-marking data, we designed a prospective, 1 year regional study comparing key performance measures with established standards for the 28 hospital Trusts in the South and West of England involved in head and neck cancer care. 566 sequential patients with a newly-diagnosed head and neck cancer were included. Numbers referred and treated per hospital Trust were 1-58 and 1-65 respectively. 59% of patients received a pretreatment chest X-ray (standard 95%). 45% of patients were seen in a multidisciplinary clinic pretreatment (standard 95%), and this was proportional to the frequency of clinics held (P<0.0001). Median number of cases treated per surgeon was 4 (1-26), and by radiotherapist was 10 (1-51). Times between parts of the process of oral cancer care were closer to the standards than those for laryngeal cancer. Two patients were entered into a clinical trial. One had a quality-of-life score. Thus, in 1996-1997, in the South and West of England, there were major discrepancies between actual performance and established standards in many fundamental aspects of head and neck cancer care. Re-audit is essential to determine if the implementation of the Calman-Hine report has resulted in improvements.

Cushing's syndrome associated with a chemodectoma and a carcinoid tumour

We present a case of Cushing's syndrome where 111In-octreotide scanning provided evidence for the presence of two neuroendocrine tumours. Uptake in the right neck corresponded to a chemodectoma, but there was no change in the clinical condition or fall in ACTH levels following surgical resection. Uptake in the left chest was assumed to relate to a bronchial carcinoid, but a tumour could not initially be localized on magnetic resonance imaging (MRI), spiral CT scanning or on selective venous sampling. A 1 cm bronchial carcinoid tumour was identified post-mortem which immunostained for ACTH. This case demonstrates that 111ln-octreotide scanning is a useful technique for identifying the source of ectopic ACTH production in difficult cases of Cushing's syndrome. Reliance should not be placed solely on standard imaging techniques to localize the tumour prior to surgery. Although rare, the possibility of a non-ACTH secreting neuroendocrine tumour should also be considered in patients with ectopic ACTH syndrome, who have positive 111In-octreotide scans.

Association of beta 1 integrin with focal adhesion kinase and paxillin in differentiating Schwann cells

Schwann cells (SCs) differentiate into a myelinating cell when simultaneously adhering to an axon destined for myelination and basal lamina. We are interested in defining the signaling pathway activated by basal lamina. Using SC/sensory neuron (N) cocultures, we identified beta1 integrin and F-actin as components of a pathway leading to myelin gene expression and myelination (Fernandez-Valle et al., 1994, 1997). Here, we show that focal adhesion kinase (FAK) and paxillin are constitutively expressed by SCs contacting axons in the absence of basal lamina. Tyrosine phosphorylation of FAK and paxillin increases as SCs form basal lamina and differentiate. FAK and paxillin specifically coimmunoprecipitate with beta1 integrin in differentiating SC/N cocultures but not SC-only cultures. Paxillin coimmunoprecipitates with FAK and fyn kinase in differentiating SC/N cocultures. A subset of tyrosine-phosphorylated beta1 integrin, FAK, and paxillin molecules reside in the insoluble, F-actin-rich fraction of differentiating cocultures. Cytochalasin D, an actin depolymerizing agent, decreases tyrosine phosphorylation of FAK and paxillin and their association with beta1 integrin and causes a dose-dependent increase in the abundance of insoluble FAK and paxillin complexes. Collectively, our work indicates that beta1 integrin, FAK, paxillin, and fyn kinase form an actin-associated complex in SCs adhering to basal lamina in the presence of axons. This complex may be important for initiating the process of SC differentiation into a myelinating cell.

Dorsal thoracic cord compression from a spinal angiolipoma: case report and brief comment

Angiolipomas are benign tumors usually found in the forearms of young adults. To the best of our knowledge only 63 cases of spinal angiolipomas have been reported in the literature up until 1999 (MEDLINE 1966-1999). We report a case of a spinal angiolipoma causing dorsal cord compression in a 44-year-old woman presenting with subacute lower limb paresthesias, in the absence of sensory or motor findings, which mimicked multiple sclerosis by history. Operative intervention was curative.

Conformational studies of the glycopeptide Ac-Tyr-[Man5GlcNAc-beta-(1-->4)GlcNAc-beta-(1-->Ndelta)]-Asn-Leu-Thr-Se r-OBz and the constituent peptide and oligosaccharide

Glycopeptides of desired structure can be conveniently prepared by the coupling of reducing oligosaccharides to aspartic acid of peptides via their glycosylamines formed in the presence of saturated aqueous ammonium hydrogen carbonate. The resulting oligosaccharide chains are N-linked to asparagine as in natural glycoproteins, allowing different peptide oligosaccharide combinations to be analysed for conformational effects. In the present paper, a pentapeptide of ovalbumin was coupled to Man5GlcNAc2 oligosaccharide and the glycopeptide and the two parent compounds compared by NMR ROESY experiments and molecular dynamics simulations. Despite the small size of the peptide, conformational effects were observed suggestive of the oligosaccharide stabilising the peptide in solution and of the peptide influencing oligosaccharide conformation. These effects are relevant to the function of glycosylation and the enzymic processing of oligosaccharide chains.

Patterns of shaker family gene expression in single identified neurons of the American lobster, Homarus americanus

The patterns of expression of voltage gated potassium channel genes of the Shaker family have been mapped in identified neurons of the lobster (Homarus americanus) ventral nerve cord using a single cell reverse transcriptase polymerase chain reaction procedure. Using specific oligonucleotides derived from the sequences of the shaker, shab, and shaw genes of the spiny lobster, Panulirus interruptus, we detected the corresponding potassium channel DNA fragments from Homarus americanus. The Homarus DNA fragments are 87-98% identical at the nucleotide level to the Panulirus DNA fragments. We used the Panulirus primers to measure the complement of RNAs for shaker, shab, and shaw in single identified cells that use GABA, glutamate, octopamine or serotonin as chemical messengers. Shaker and shaw RNAs were found in all four identified neuron types but shab RNA was not detected in serotonin cells under the present experimental conditions. All cells expressed alpha-tubulin RNA, which serves as an internal control suggesting that cells are intact after dissection. In glial cells that surround the neuronal cell bodies, the potassium channel genes are expressed at low to non-detectable levels.

Ischemic colitis associated with pseudoephedrine: four cases

OBJECTIVE

There is one previously reported case linking ischemic colitis and orally administered nasal decongestants containing pseudoephedrine (MEDLINE 1974-1998). We aimed to document an association between pseudoephedrine ingestion and ischemic colitis.

METHODS

We reviewed the cases of four women (ages, 37-50 yr) who presented with the sudden onset of colicky abdominal pain followed by hematochezia. Three patients had used medicine containing pseudoephedrine daily for approximately 1 wk before admission. The fourth patient had used pseudoephedrine chronically for 6 months. Two patients had no significant past medical history. One woman had presented 6 months earlier with ischemic colitis while taking both pseudoephedrine and hormone replacement therapy. This time she presented with ischemic colitis while not taking hormone replacement therapy, but still taking decongestants. Another woman had a history of ulcerative colitis, which had been quiescent for 10 yr. One patient had been a smoker; however, like the other patients she had no evidence of systemic vascular disease. On colonoscopy, all four patients had colitis, primarily affecting the splenic flexure in the anatomical watershed area. Other causes of segmental colitis, including infectious colitides, pseudomembranous colitis, and Crohn's disease, were not evident. Colonoscopic biopsies were consistent with ischemic injury.

RESULTS

All cases responded to abstinence from pseudoephedrine and medical supportive therapy. None has had a relapse since discontinuing the pseudoephedrine (8-12 months).

CONCLUSIONS

The vasoconstrictive action of pseudoephedrine may predispose susceptible patients to develop ischemic colitis in the watershed area of the splenic flexure. Perimenopausal women may be especially susceptible because of irregular ovulation. This may result in relative vasoconstriction when estrogen levels are low or a hypercoagulable state when estrogen levels are excessive.

A tyrosine-phosphorylated protein that binds to an important regulatory region on the cool family of p21-activated kinase-binding proteins

The p21-activated kinases (Pak) are major targets of the small GTPases Cdc42 and Rac. We, and others, recently identified a family of proteins termed Cool/Pix, which interact with Pak3. In cells, p50(Cool-1) suppresses Pak activation by upstream activators; p85(Cool-1) has a permissive effect on Pak activation, and we now show that the closely related Cool-2 stimulates Pak kinase activity. To understand the differential regulation of Pak by Cool proteins, we screened for Cool-interacting proteins by affinity purification and microsequencing. This has led to the identification of two closely related proteins called Cat (Cool-associated, tyrosine phosphorylated), which contain a zinc finger followed by three ankyrin repeats. Cat-1 is identical to the recently identified binding partner for the beta-adrenergic receptor kinase (betaARK or GRK-2), which was shown to have Arf-GAP activity. Cat-1 and Cat-2 both bind to the COOH-terminal region of p85(Cool-1) and p85(Cool-2) but do not bind to p50(Cool-1). Cat-1 is tyrosine-phosphorylated in growing NIH 3T3 fibroblasts, and its tyrosine phosphorylation is increased following cell spreading on fibronectin, decreased in cells arrested in mitosis, and increased in the ensuing G(1) phase. Cat proteins are tyrosine-phosphorylated when co-expressed in cells with the focal adhesion kinase Fak and Src. These findings suggest that in addition to playing a role in Cool/Pak interactions, Cat proteins may serve as points of convergence between G protein-coupled receptors, integrins, Arf GTPases, cell cycle regulators, and Cdc42/Rac/Pak signaling pathways.

Needle-in-a-haystack detection and identification of base substitution mutations in human tissues

Background and induced germline mutagenesis and other genotoxicity studies have been hampered by the lack of a sufficiently sensitive technique for detecting mutations in a small cluster of cells or a single cell in a tissue sample composed of millions of cells. The most frequent type of genetic alteration is intragenic. The vast majority of oncogenic mutations in human and mammalian cancer involves only single base substitutions. We have developed universally applicable techniques that not only provide the necessary sensitivity and specificity for site specific mutagenesis studies, but also identify the point mutation. The exponential amplification procedures of polymerase chain reaction (PCR) and ligase chain reaction (LCR) have been combined with restriction endonuclease (RE) digestion to enable the selective enrichment and detection of single base substitution mutations in human oncogenic loci at a sensitivity of one mutant in more than 10(7) wild type alleles. These PCR/RE/LCR procedures have been successfully designed and used for codons 12 and 248 of the Ha-ras and p53 genes, respectively, both of which contain a natural MspI restriction endonuclease recognition sequence. These procedures have also been adapted for the detection and identification of mutations in oncogenic loci that do not contain a natural restriction endonuclease recognition sequence. Using PCR techniques, a HphI site was incorporated into the codons 12/13 region of the human N-ras gene, which was then used for the selective enrichment of mutants at this oncogenic locus. These PCR/RE/LCR procedures for base substitution mutations in codon 12 of the N-ras gene were found to have the sensitivity of detection of at least one mutant allele in the presence of the DNA equivalent of 10(6) wild type cells. Only one peripheral blood leukocyte DNA specimen out of nine normal individuals displayed an observable Ha-ras mutation that was present at frequency between 10(-5) and 10(-6). These PCR/RE/LCR techniques for detecting and identifying base substitution mutations are universally applicable to almost any locus or base site within the human or animal genome. With the added advantage of the adjustability of both the amount of DNA (number of genomes) to be tested and the sensitivity (10(-2) to 10(-7)) of the assay selection or enrichment procedures, these PCR/RE/LCR techniques will be useful in addressing a broad range of important questions in mutagenesis and carcinogenesis.

Chromosomal deletions occur in restricted regions of 5q in testicular germ cell cancer

Since the biologic behavior and molecular genetic changes observed in testicular germ cell cancer differ from those seen in more common epithelial tumors, it is likely that hitherto uncharacterized genes play a role in the development of germ cell tumors. Our previous work on testicular germ cell cancer suggested that chromosome 5q might contain one or more novel tumor suppressor genes that play a role in this malignancy. In this study, we performed a high resolution loss of heterozygosity (LOH) study of testicular cancer using 37 informative markers on chromosome 5. We detected allelic losses in 20/48 (42%) specimens and identified three common sites of loss on chromosome 5q14, 5q21 and 5q34-qter, defined respectively by minimal regions of deletion of < or = 1 cM, 10 cM and approximately 20 (cM). Using an overlapping series of YACs and radiation hybrid mapping, we have constructed a physical map of the 5q14 deletion that should aid in the isolation and characterization of the putative tumor suppressor gene located therein.

Characterization and distribution of an oncofetal antigen (M2A antigen) expressed on testicular germ cell tumours

M2A antigen is an oncofetal antigen associated with germ cell neoplasia, present in testis on fetal gonocytes and re-expressed on carcinoma in situ (CIS) and germ cell tumours. We developed a panel of monoclonal antibodies (mAb), M2A (IgG2a), D1-26 (IgG2b) and D2-40 (IgG1), to this antigen in order to characterize its structure and study its distribution among germ cell tumours. M2A antigen was purified by sequential lectin and antibody affinity chromatography and characterized as a monomeric M, 40 000 surface sialoglycoprotein, extensively glycosylated with O-linked carbohydrate structures, but devoid of N-linked sugars. Terminal sialic acid residues were required for reactivity with mAb M2A and D1-26, but not D2-40. Sections of 69 testicular germ cell tumours, fixed in formalin and embedded in paraffin, were stained with mAb D2-40 to examine the distribution of M2A antigen. Uniform membrane staining was observed in seminomas, and focal staining in 69% of embryonal carcinomas, 29% of teratomas and 25% of yolk sac tumours. CIS in the vicinity of all germ cell tumours also displayed uniform membrane staining. The characterization of M2A antigen, and the development of mAb which react with it in conventionally preserved archival specimens, provide important initiatives to study the origin and progression of germ cell neoplasia.

Identification of the cerebral loci processing human swallowing with H2(15)O PET activation

Lesional and electrophysiological data implicate a role for the cerebral cortex in the initiation and modulation of human swallowing, and yet its functional neuroanatomy remains undefined. We therefore conducted a functional study of the cerebral loci processing human volitional swallowing with 15O-labeled water positron emission tomography (PET) activation imaging. Regional cerebral activation was investigated in 8 healthy right handed male volunteers with a randomized 12-scan paradigm of rest and water swallows (5 ml/bolus, continuous infusion) at increasing frequencies of 0.1, 0.2, and 0.3 Hz, which were visually cued and monitored with submental electromyogram (EMG). Group and individual linear covariate analyses were performed with SPM96. In five of eight subjects, the cortical motor representation of pharynx was subsequently mapped with transcranial magnetic stimulation (TMS) in a posthoc manner to substantiate findings of hemispheric differences in sensorimotor cortex activation seen with PET. During swallowing, group PET analysis identified increased regional cerebral blood flow (rCBF) (P < 0.001) within bilateral caudolateral sensorimotor cortex [Brodmann's area (BA) 3, 4, and 6], right anterior insula (BA 16), right orbitofrontal and temporopolar cortex (BA 11 and 38), left mesial premotor cortex (BA 6 and 24), left temporopolar cortex and amygdala (BA 38 and 34), left superiomedial cerebellum, and dorsal brain stem. Decreased rCBF (P < 0.001) was also observed within bilateral posterior parietal cortex (BA 7), right anterior occipital cortex (BA 19), left superior frontal cortex (BA 8), right prefrontal cortex (BA 9), and bilateral superiomedial temporal cortex (BA 41 and 42). Individual PET analysis revealed asymmetric representation within sensorimotor cortex in six of eight subjects, four lateralizing to right hemisphere and two to left hemisphere. TMS mapping in the five subjects identified condordant interhemisphere asymmetries in the motor representation for pharynx, consistent with the PET findings. We conclude that volitional swallowing recruits multiple cerebral regions, in particular sensorimotor cortex, insula, temporopolar cortex, cerebellum, and brain stem, the sensorimotor cortex displaying strong degrees of interhemispheric asymmetry, further substantiated with TMS. Such findings may help explain the variable nature of swallowing disorders after stroke and other focal lesions to the cerebral cortex.

Reversion of the differentiated phenotype and maturation block in Sertoli cells in pathological human testis

To study the relationship between abnormal Sertoli cell differentiation and spermatogenic impairment, we examined the expression of Sertoli cell markers normally lost at puberty, cytokeratin 18 (CK18), anti-Müllerian hormone (AMH) and M2A antigen, in three children (aged 1-2 years), 50 adults (aged 19-45 years) with obstructive or non-obstructive azoospermia or oligozoospermia, and six patients (aged 1-18 years) with 5 alpha-reductase deficiency. There was CK18 and/or AMH expression, but never M2A antigen expression, associated with spermatogonial arrest or Sertoli cell-only (SCO) syndrome in infertile men. Loss of M2A antigen suggests the transition of Sertoli cells to an adult phenotype, while CK18 and/or AMH expression may be a manifestation of de-differentiation of Sertoli cells. In 5 alpha-reductase deficiency, there was a sequential loss of CK18, M2A antigen and AMH around puberty, associated with partial spermatogenesis. The persistence of immature Sertoli cells expressing M2A antigen was associated with prepubertal seminiferous cords and SCO syndrome. Therefore, 5 alpha-reductase deficiency may prevent the maturation of Sertoli cells, resulting in impairment of spermatogenesis, and loss of M2A antigen expression coincides with a critical step in the Sertoli cell maturation. High follicle stimulating hormone concentrations due to failure of normal Sertoli cell differentiation indicate a normal development pattern of the hypothalamic-pituitary-gonadal axis.

Characterization of oligosaccharides from an antigenic mannan of Saccharomyces cerevisiae

Mannans of the yeast Saccharomyces cerevisiae have been implicated as containing the allergens to which bakers and brewers are sensitive and also the antigen recognized by patients with Crohn's disease. A fraction of S. cerevisiae mannan, Sc500, having high affinity for antibodies in Crohn's patients has been characterized by NMR spectroscopy followed by fragmentation using alkaline elimination, partial acid hydrolysis and acetolysis. The released oligosaccharides were separated by gel filtration on a Biogel P4 column and analyzed by fluorescence labeling, HPLC and methylation analysis. The relationship between structure and antigen activity was measured by competitive ELISA. The antigenic activity of the original high molecular weight mannan could be ascribed to terminal Manalpha1-->3Manalpha1-->2 sequences which are rarely found in human glycoproteins but were over-represented in Sc500 compared to other yeast mannans.

A guide to finding and evaluating best practices health care information on the Internet: the truth is out there?

BACKGROUND

The advent of virtually free Internet access has opened large vistas of health care information to those willing to invest a small amount of time and energy learning how to perform searches using browser software. Health care providers, organizations, and professional associations, among many others, publish "best practices" information for both administrative and clinical audiences, making these recommendations among the fastest-growing types of health care information appearing on the World Wide Web. The problem is how to find best practices among the wealth of resources on the Internet and then how to separate the proverbial wheat from the chaff. WHO IS SEEKING BEST PRACTICES ON THE INTERNET? Best practice describes a process or technique whose employment results in improved patient and/or organizational outcomes. Health care providers, managed care organizations, administrators, payers, and policy analysts are all interested in improving the quality of health care and are likely to be customers of best practices informational resources. HOW TO EVALUATE THE QUALITY OF BEST PRACTICES INFORMATION? Once the information is available on the Internet, the problem for the searcher shifts from one of quantity to quality. The best practices information seeker should stop and ask a number of questions about the quality of information, its sources, and the methods used to obtain it.

CONCLUSION

The "truth" may be out there some-where in cyberspace, but locating best practices information and evaluating its quality require new skills and patience and time to practice and develop them to the point of efficiency.