Functional Pdgfra fibroblast heterogeneity in normal and fibrotic mouse lung

Aberrant fibroblast function plays a key role in the pathogenesis of idiopathic pulmonary fibrosis, a devastating disease of unrelenting extracellular matrix deposition in response to lung injury. Platelet-derived growth factor α-positive (Pdgfra+) lipofibroblasts (LipoFBs) are essential for lung injury response and maintenance of a functional alveolar stem cell niche. Little is known about the effects of lung injury on LipoFB function. Here, we used single-cell RNA-Seq (scRNA-Seq) technology and PdgfraGFP lineage tracing to generate a transcriptomic profile of Pdgfra+ fibroblasts in normal and injured mouse lungs 14 days after bleomycin exposure, generating 11 unique transcriptomic clusters that segregated according to treatment. While normal and injured LipoFBs shared a common gene signature, injured LipoFBs acquired fibrogenic pathway activity with an attenuation of lipogenic pathways. In a 3D organoid model, injured Pdgfra+ fibroblast-supported organoids were morphologically distinct from those cultured with normal fibroblasts, and scRNA-Seq analysis suggested distinct transcriptomic changes in alveolar epithelia supported by injured Pdgfra+ fibroblasts. In summary, while LipoFBs in injured lung have not migrated from their niche and retain their lipogenic identity, they acquire a potentially reversible fibrogenic profile, which may alter the kinetics of epithelial regeneration and potentially contribute to dysregulated repair, leading to fibrosis.

A distinct innate lymphoid cell population regulates tumor-associated T cells

Antitumor T cells are subject to multiple mechanisms of negative regulation. Recent findings that innate lymphoid cells (ILCs) regulate adaptive T cell responses led us to examine the regulatory potential of ILCs in the context of cancer. We identified a unique ILC population that inhibits tumor-infiltrating lymphocytes (TILs) from high-grade serous tumors, defined their suppressive capacity in vitro, and performed a comprehensive analysis of their phenotype. Notably, the presence of this CD56+CD3- population in TIL cultures was associated with reduced T cell numbers, and further functional studies demonstrated that this population suppressed TIL expansion and altered TIL cytokine production. Transcriptome analysis and phenotypic characterization determined that regulatory CD56+CD3- cells exhibit low cytotoxic activity, produce IL-22, and have an expression profile that overlaps with those of natural killer (NK) cells and other ILCs. NKp46 was highly expressed by these cells, and addition of anti-NKp46 antibodies to TIL cultures abrogated the ability of these regulatory ILCs to suppress T cell expansion. Notably, the presence of these regulatory ILCs in TIL cultures corresponded with a striking reduction in the time to disease recurrence. These studies demonstrate that a previously uncharacterized ILC population regulates the activity and expansion of tumor-associated T cells.

Incidence and outcomes of ventral hernia repair after robotic retropubic prostatectomy: A retrospective cohort of 570 consecutive cases

BACKGROUND

Robotic retropubic prostatectomy (RRP) has become one of the most commonly performed robotic procedures in the United States. Ventral hernia (VH) has been increasingly recognized as an important complication after laparoscopic procedures, in general. However, data related to VH after robotic procedures is relatively scarce, especially after RRP. With increasing popularity of RRP, the purpose of this study was to look at the incidence of VH and outcomes of ventral hernia repair (VHR) after RRP.

METHODS

All patients who underwent RRP at a single institution between January 2012 and June 2014 were studied retrospectively using electronic medical records.

RESULTS

A total of 570 patients underwent RRP, of which 33 (5.8%) developed VH during the study period. Fourteen (42%) patients were obese and five (15%) had diabetes. One patient (3%) had a surgical site infection after RRP and two (6%) patients were on immunomodulators/steroids. Median duration to develop VH after RRP was 12 (1-25) months. Out of the 33 patients with VH, ten (33%) underwent VHR; five laparoscopic and five open. Median size of hernia defect and mesh used was 25 (1-144) cm² and 181 (15-285) cm², respectively. Median length of hospital stay and follow up was 0 (0-4) days and 12 (1-14) months, respectively. One patient who had initial VHR done at an outside institution had a recurrence. Thirty-two (97%) patients were alive at their last follow up. One patient died secondary to progression of prostate cancer. There was no significant 30 day morbidity (surgical site infection, fascial dehiscence, pneumonia, acute kidney injury, myocardial infarction). Of patients who decided non-operative management of VH (n = 23, 67%), none developed a complication requiring emergent surgical intervention.

CONCLUSION

The incidence of VH after RRP is likely underreported in prior studies. Repair, either laparoscopic or open, is safe and effective in experienced hands. Patients who decide on watchful waiting can be followed with minimal risk of incarceration/strangulation. Further studies are needed to analyze the extraction techniques after RRP and correlate with incidence of VH.

The difficult gall bladder: Outcomes following laparoscopic cholecystectomy and the need for open conversion

INTRODUCTION

Surgery for the difficult gallbladder (DGB) is associated with increased risk compared to more routine laparoscopic cholecystectomies (LC). Laparoscopic "damage control" methods including cholecystostomy, fundus-down approach and subtotal cholecystectomy (SC) have been proposed to avoid conversion to open. We hypothesized that a Total LC (TLC) for DBG can be completed safely with an acceptably low conversion rate.

MATERIAL AND METHODS

All patients that underwent LC from January 2005-June 2015 were retrospectively reviewed. Cases met criteria for DGB if they were necrotic/gangrenous, involved Mirizzi syndrome, had extensive adhesions, were converted to open, lasted more than 120 min, had prior tube cholecystostomy or known GB perforation.

RESULTS

A total of 2212 patients underwent LC during the study time period, of which 351 (15.8%) met criteria for DGB. Of these cases, 213 (60.7%) were admitted from the emergency department and 67 (19.1%) underwent urgent/emergent cholecystectomy (within 24 h). Additionally 18 (5.1%) had pre-operative tube cholecystostomies. Seventy patients (19.9%) were converted to open. Indications for conversion included severe inflammation/adhesion (n = 31, 46.3%), difficult anatomy (n = 14, 20.9%) and bleeding (n = 6, 9.0%). Predictors for conversion included urgent/emergent intervention (OR, 0.80; 95% CI 0.351-0.881, p = 0.032), previous abdominal surgery (OR, 2.18; 95% CI, 1.181-4.035, p = 0.013) and necrotic/gangrenous cholecystitis (OR, 1.92; 95% CI, 1.356-4.044, p = 0.033). Comparing the TLC and the conversion groups, mean operative time and length of hospital stay were significantly different; 147 ± 47 min vs 185 ± 71 min; p < 0.005 and 3 ± 2 days vs 5 ± 3 days; p = 0.011, respectively. There was no significant difference in postoperative hemorrhage, subhepatic collection, cystic duct leak, wound infection, reoperation and 30 day mortality. There was no bile duct injury in either group.

CONCLUSION

Total laparoscopic cholecystectomy can be safely performed in difficult gallbladder situations with a lower conversion rate than previously reported. Possible predictors of conversion include urgency, necrotic gallbladder and history of prior abdominal surgeries. For patients converted to open, similar morbidity and mortality can be expected.

Nomogram to predict perioperative blood transfusion for hepatopancreaticobiliary and colorectal surgery

Background

Predictive tools assessing risk of transfusion have not been evaluated extensively among patients undergoing complex gastrointestinal surgery. In this study preoperative variables associated with blood transfusion were incorporated into a nomogram to predict transfusion following hepatopancreaticobiliary (HPB) or colorectal surgery.

Methods

A nomogram to predict receipt of perioperative transfusion was developed using a cohort of patients who underwent HPB or colorectal surgery between January 2009 and December 2014. The discriminatory ability of the nomogram was tested using the area under the receiver operating characteristic (ROC) curve and internal validation performed via bootstrap resampling.

Results

Among 4961 patients undergoing either a HPB (56·3 per cent) or colorectal (43·7 per cent) resection, a total of 1549 received at least 1 unit of packed red blood cells, giving a perioperative transfusion rate of 31·2 per cent. On multivariable analysis, age 65 years and over (odds ratio (OR) 1·52), race (versus white: black, OR 1·58; Asian, OR 1·86), preoperative haemoglobin 8·0 g/dl or less (versus over 12·0 g/dl: OR 26·79), preoperative international normalized ratio more than 1·2 (OR 2·44), Charlson co-morbidity index score over 3 (OR 1·86) and procedure type (versus colonic surgery: major hepatectomy, OR 1·71; other pancreatectomy, OR 2·12; rectal surgery, OR 1·39; duodenopancreatectomy, OR 2·65) were associated with a significantly higher risk of transfusion and were included in the nomogram. A nomogram was constructed to predict transfusion using these seven variables. Discrimination and calibration of the nomogram revealed good predictive abilities (area under ROC curve 0·756).

Conclusion

The nomogram predicted blood transfusion in major HPB and colorectal surgery.

Development and validation of the Australian Aboriginal racial identity and self-esteem survey for 8-12 year old children (IRISE_C)

INTRODUCTION

In Australia, there is little empirical research of the racial identity of Indigenous children and youth as the majority of the current literature focuses on adults. Furthermore, there are no instruments developed with cultural appropriateness when exploring the identity and self-esteem of the Australian Aboriginal population, especially children. The IRISE_C (Racial Identity and Self-Esteem of children) inventory was developed to explore the elements of racial identity and self-esteem of urban, rural and regional Aboriginal children. This paper describes the development and validation of the IRISE_C instrument with over 250 Aboriginal children aged 8 to 12 years.

METHODS

A pilot of the IRISE C instrument was combined with individual interviews and was undertaken with 35 urban Aboriginal children aged 8-12 years. An exploratory factor analysis was performed to refine the survey and reduce redundant items in readiness for the main study. In the main study, the IRISE C was employed to 229 Aboriginal children aged 6-13 years across three sites (rural, regional and urban) in Western Australia. An exploratory factor analysis using Principal axis factoring was used to assess the fit of items and survey structure. A confirmatory factor analysis was then employed using LISREL (diagonally weighted least squares) to assess factor structures across domains. Internal consistency and reliability of subscales were assessed using Cronbach's co-efficient alpha.

RESULTS

The pilot testing identified two key concepts - children's knowledge of issues related to their racial identity, and the importance, or salience, that they attach to these issues. In the main study, factor analyses showed two clear factors relating to: Aboriginal culture and traditions; and a sense of belonging to an Aboriginal community. Principal Axis Factoring of the Knowledge items supported a 2-factor solution, which explained 38.7% of variance. Factor One (Aboriginal culture) had a Cronbach's alpha of 0.835; Factor 2 (racial identity) had a Cronbach's alpha of 0.800, thus demonstrating high internal reliability of the scales.

CONCLUSION

The IRISE_C has been shown to be a valid instrument useful of exploring the development of racial identity of Australian Aboriginal children across the 8-12 year old age range and across urban, rural and regional geographical locations.

Shp1 regulates T cell homeostasis by limiting IL-4 signals

Absence of the phosphatase Shp1 in T cells does not affect the TCR signaling threshold but results in IL-4 sensitivity and memory phenotype cells.

The protein-tyrosine phosphatase Shp1 is expressed ubiquitously in hematopoietic cells and is generally viewed as a negative regulatory molecule. Mutations in Ptpn6, which encodes Shp1, result in widespread inflammation and premature death, known as the motheaten (me) phenotype. Previous studies identified Shp1 as a negative regulator of TCR signaling, but the severe systemic inflammation in me mice may have confounded our understanding of Shp1 function in T cell biology. To define the T cell–intrinsic role of Shp1, we characterized mice with a T cell–specific Shp1 deletion (Shp1^fl/fl CD4-cre). Surprisingly, thymocyte selection and peripheral TCR sensitivity were unaltered in the absence of Shp1. Instead, Shp1^fl/fl CD4-cre mice had increased frequencies of memory phenotype T cells that expressed elevated levels of CD44. Activation of Shp1-deficient CD4⁺ T cells also resulted in skewing to the Th2 lineage and increased IL-4 production. After IL-4 stimulation of Shp1-deficient T cells, Stat 6 activation was sustained, leading to enhanced Th2 skewing. Accordingly, we observed elevated serum IgE in the steady state. Blocking or genetic deletion of IL-4 in the absence of Shp1 resulted in a marked reduction of the CD44^hi population. Therefore, Shp1 is an essential negative regulator of IL-4 signaling in T lymphocytes.

Molecular programming of steady-state dendritic cells: impact on autoimmunity and tumor immune surveillance

Dendritic cells are master regulators of immunity. Immature dendritic cells are essential for maintaining self-tolerance, while mature dendritic cells initiate a variety of specialized immune responses. Dendritic cell quiescence is often viewed as a default state that requires exogenous stimuli to induce maturation. However, recent studies have identified dendritic cell quiescence factors that actively program dendritic cells to an immature state. In the absence of these factors, dendritic cells spontaneously become immunogenic and can induce autoimmune responses. Herein we discuss two such factors, NF-κB1 and A20, that preserve dendritic cell immaturity through their regulation of NF-κB signaling. Loss of either of these factors increases dendritic cell immunogenicity, suggesting that they may be important targets for enhancing dendritic cell-based cancer immunotherapies. Alternatively, defects in molecules critical for maintaining steady-state DCs may provide novel biomarkers that identify patients who have enhanced natural antitumor immunity or that correlate with better responses to various immunotherapies.

Inguinal hernia repair in women: is the laparoscopic approach superior?

PURPOSE

Laparoscopic inguinal hernia repair is associated with reduced post-operative pain and earlier return to work in men. However, the role of laparoscopic hernia repair in women is not well reported. The aim of this study was to review the outcomes of the laparoscopic versus open repair of inguinal hernias in women and to discuss patients' considerations when choosing the approach.

METHODS

A retrospective chart review of all consecutive patients undergoing inguinal hernia repair from January 2005 to December 2009 at a single institution was conducted. Presentation characteristics and outcome measures including recurrence rates, post-operative pain and complications were compared in women undergoing laparoscopic versus open hernia repair.

RESULTS

A total of 1,133 patients had an inguinal herniorrhaphy. Of these, 101 patients were female (9 %), with a total of 111 hernias. A laparoscopic approach was chosen in 44 % of patients. The majority of women (56 %) presented with groin pain as the primary symptom. Neither the mode of presentation nor the presenting symptoms significantly influenced the surgical approach. There were no statistically significant differences in hernia recurrence, post-operative neuralgia, seroma/hematoma formation or urinary retention between the two approaches (p < 0.05). A greater proportion of patients with bilateral hernias had a laparoscopic approach rather than an open technique (12 vs. 2 %, p = 0.042).

CONCLUSIONS

Laparoscopic herniorrhaphy is as safe and efficacious as open repair in women, and should be considered when the diagnosis is in question, for management of bilateral hernias or when concomitant abdominal pathology is being addressed.

HIV delays IFN-α production from human plasmacytoid dendritic cells and is associated with SYK phosphorylation

Plasmacytoid dendritic cells (pDC) are the major producers of type I interferons (IFNs) in humans and rapidly produce IFN-α in response to virus exposure. Although HIV infection is associated with pDC activation, it is unclear why the innate immune response is unable to effectively control viral replication. We systematically compared the effect of HIV, Influenza, Sendai, and HSV-2 at similar target cell multiplicity of infection (M.O.I.) on human pDC function. We found that Influenza, Sendai, HSV-2 and imiquimod are able to rapidly induce IFN-α production within 4 hours to maximal levels, whereas HIV had a delayed induction that was maximal only after 24 hours. In addition, maximal IFN-α induction by HIV was at least 10 fold less than that of the other viruses in the panel. HIV also induced less TNF-α and MIP-1β but similar levels of IP-10 compared to other viruses, which was also mirrored by delayed upregulation of pDC activation markers CD83 and CD86. BDCA-2 has been identified as an inhibitory receptor on pDC, signaling through a pathway that involves SYK phosphorylation. We find that compared to Influenza, HIV induces the activation of the SYK pathway. Thus, HIV delays pDC IFN-α production and pDC activation via SYK phosphorylation, allowing establishment of viral populations.

Distribution of bluetongue in the United States of America, 1991-2002

Bluetongue virus (BTV) distribution in the United States of America (USA) is limited by the range of the vector Culicoides spp. Regional differences exist with the north-eastern states being free of BTV, while the central and north-western states are seasonally free of virus. Activity of the virus can be observed throughout the year in the southern USA. Serological evidence defining the distribution of BTV in selected regions of the USA is gathered regularly through serological surveys conducted on samples from slaughter cattle. From 1991 to 2002, ten serological surveys were completed. Results from Alaska, Hawaii, Michigan, Minnesota, New York, Wisconsin and New England consistently demonstrated a seropositive rate of less than 2%, confirming BTV-free status. Antibody against BTV was sporadically detected in cattle originating from states contiguous to the BTV-free regions. Additional information on BTV distribution in the USA is obtained through identification of BTV or BTV RNA in diagnostic, surveillance and export specimens submitted to the National Veterinary Services Laboratories. Results confirm that BTV serotypes 2, 10, 11, 13 and 17 are present in the USA.

Characterizing the influence of structure and route of exposure on the disposition of dithiocarbamates using toluene-3,4-dithiol analysis of blood and urinary carbon disulfide metabolites

Differences in the toxicities observed for dithiocarbamates have been proposed to result from the influence of nitrogen substitution, oxidation state, and route of exposure. To better characterize the fate of dithiocarbmates in vivoas a function of structure and route of exposure, rats were administered equimolar doses of carbon disulfide (CS2), N-methyldithiocarbamate, pyrrolidine dithiocarbamate, N,N-diethyldithiocarbamate, or disulfiram daily for five days, either po or ip, and sequential blood samples obtained. Protein dithiocarbamates formed by the in vivo release of CS2, parent dithiocarbamate, and protein-bound mixed disulfides were assessed in plasma and hemolysate by measuring toluene trithiocarbonate generated upon treatment with toluene-3, 4-dithiol (TdT). To aid in determining the bioavailability of CS2 from the administered dithiocarbamates, the urinary CS2 metabolites, 2-thiothiazolidine-4-carboxylic acid (TTCA) and 2-thiothiazolidin-4-ylcarbonylglycine (TTCG), were also determined. The levels of TdT-reactive moieties detected depended upon both the compound administered and the route of exposure. Parent dithiocarbamates, with the exception of disulfiram, were eliminated from blood within 24 h; but protein associated TdT-reactive moieties persisted and accumulated with repeated exposure, regardless of the route of exposure. N-Methyldithiocarbamate demonstrated the greatest potential to produce intracellular globin modifications, presumably through its unique ability to generate a methylisothiocyanate metabolite. Urinary excretion of TTCA and TTCG was more sensitive than TdT analysis for detecting dithiocarbamate exposure, but TdT analysis appeared to be a better indicator of in vivo release of CS2 by dithiocarbamates than were urinary CS2 metabolites. These data suggest that CS2 is a more important metabolite, following oral exposure, than are other routes of exposure, e.g., inhalation or dermal. In addition, data also suggest that acid stability, nitrogen substitution, and route of exposure are important factors governing the toxicity observed for a particular dithiocarbamate.

Stable recombinant expression and characterization of the two haemophilic factor VIII variants C329S (CRM(-)) and G1948D (CRM(r))

In haemophilia A, the functional defect at the molecular level of most factor VIII (FVIII) missense mutations remains unknown. Site-directed mutagenesis of B domain-deleted FVIII cDNA (FVIIISQ) was used to introduce two mutations associated with severe cross-reacting material (CRM)-negative (FVIII-C329S) or mild/moderate CRM-reduced (FVIII-G1948D) haemophilia A. Wild-type (FVIIISQ-WT) and variant FVIIISQ proteins were successfully expressed after stable transfection in Chinese hamster ovary (CHO) cells, and partially characterized at the intracellular, molecular and functional levels. Reverse transcription polymerase chain reaction analysis confirmed that both transcription and mRNA processing appeared normal in CHO cells transfected with both the wild-type and two variant constructs. In contrast to FVIIISQ-WT, immunofluorescence analysis of both CRM(-) and CRM(r) variants showed intracellular FVIII accumulation within the rough endoplasmic reticulum, suggesting secretion defects in transfected CHO cells. Immunoblot analysis of the FVIIISQ variant proteins that were secreted showed that they were expressed as mixed populations of uncleaved 170 kDa polypeptides, processed 90 kDa heavy chains and 80 kDa light chains, similar to FVIIISQ-WT. Phenotypic analysis of the B domain-deleted FVIIISQ variants expressed in CHO cells correlated well with the patients' reduced FVIII activity and, in addition, surface plasmon resonance studies demonstrated that both missense mutations were associated with increased rates of A2 domain dissociation following thrombin activation. We conclude that the mutations found are responsible for the haemophilia A phenotype, through intracellular retention and decreased stability of the active cofactor FVIIIa.

Can costs be measured and predicted by modeling within a cooperative clinical trials group? Economic methodologic pilot studies of the radiation therapy oncology group (RTOG) studies 90-03 and 91-04

PURPOSE

To (1) measure radiation therapy costs for patients in randomized controlled clinical trials, (2) compare measured costs to modeling predictions, (3) examine cost distributions, and (4) assess feasibility of collecting economic data within a cooperative group.

METHODS

The Radiation Therapy Oncology Group conducted economic pilot studies for two Phase III studies that compared fractionation patterns. Expected quantities of Current Procedural Terminology (CPT) codes and relative value units (RVU) were modeled. Institutions retrospectively provided procedure codes, quantities, and components, which were converted to RVUs used for Medicare payments. Cases were included if the radiation therapy quality control review judged them to have been treated per protocol or with minor variation. Cases were excluded if economic quality review found incomplete economic data.

RESULTS

The median and mean RVUs were within the range predicted by the model for all arms of one study and above the predicted range for the other study.

CONCLUSION

The model predicted resource use well for patients who completed treatment per protocol. Actual economic data can be collected for critical cost items. Some institutions experienced difficulty collecting retrospective data, and prospective collection of data is likely to allow wider participation in future Radiation Therapy Oncology Group economic studies.

Detection of North American West Nile virus in animal tissue by a reverse transcription-nested polymerase chain reaction assay

A traditional single-stage reverse transcription-polymerase chain reaction (RT-PCR) procedure is effective in determining West Nile (WN) virus in avian tissue and infected cell cultures. However, the procedure lacks the sensitivity to detect WN virus in equine tissue. We describe an RT-nested PCR (RT-nPCR) procedure that identifies the North American strain of WN virus directly in equine and avian tissues.

Equine West Nile encephalitis, United States

After the 1999 outbreak of West Nile (WN) encephalitis in New York horses, a case definition was developed that specified the clinical signs, coupled with laboratory test results, required to classify cases of WN encephalitis in equines as either probable or confirmed. In 2000, 60 horses from seven states met the criteria for a confirmed case. The cumulative experience from clinical observations and diagnostic testing during the 1999 and 2000 outbreaks of WN encephalitis in horses will contribute to further refinement of diagnostic criteria.

Bcl-2 accelerates multistep prostate carcinogenesis in vivo

The impact of bcl-2 proto-oncogene expression on the pathogenesis and progression of prostate cancer was examined in a transgenic mouse model. Probasin-bcl-2 transgenic mice were crossed with TRAMP (TRansgenic Adenocarcinoma Mouse Prostate) mice that express the SV40 early genes (T/t antigens) under probasin control. Prostate size, cell proliferation, apoptosis, and the incidence and latency of tumor formation were evaluated. The double transgenic, probasin-bcl-2 X TRAMP F1 (BxT) mice exhibited an increase in the wet weight of the prostate. This was associated with an increase in proliferation, attributable to T/t antigens, and a decrease in apoptosis attributable to bcl-2. The latency to tumor formation was also decreased in the BxT mice compared to the TRAMP mice. The incidence of metastases was identical in both the TRAMP and BxT mice. Lastly, the incidence of hormone-independent prostate cancer was reduced in the BxT mice compared to the TRAMP mice. Together, these results demonstrate that bcl-2 can facilitate multistep prostate carcinogenesis in vivo.

Routine, single-item screening to identify abusive relationships in women

BACKGROUND

Abusive relationships are associated with several demographic factors and many clinical problems in women. However, practices often do not screen for abuse.

METHODS

This is a descriptive study of 1526 women aged 19 to 69 years who completed a health survey in 31 office practices. The 53-item survey included a question designed to screen for an abusive relationship. Our analysis compared self-reported measures of symptoms (N = 13) and functional limitations (n = 6) of women who had abusive relationships with those who did not. We also examined the utility of using a constellation of clinical problems to identify risk for abuse.

RESULTS

Women in abusive relationships were more likely to be poor (37% vs 14%; P < .001) and young (87% were younger than 51 years versus 69% of those who were not in such relationships; P < .001). They had twice as many bothersome symptoms (3.1 vs 1.7; P < .001) and functional problems (1.6 vs 0.8; P < .001). Approximately 40% (36/89) of low-income women with emotional problems were at risk for abuse versus only 6% (64/1025) of women with adequate financial resources and no emotional problems. However, because so many women were at low risk, almost twice as many in this group (n = 64) reported abusive relationships than in the high-risk group (n = 36).

CONCLUSIONS

Women in abusive relationships have many symptoms and functional limitations. However, symptoms and clinical problems provide insufficient clues for abuse. It is better just to ask. A single-item screening question appears adequate for this purpose.

Validation of a reverse transcriptase multiplex PCR test for the serotype determination of U.S. isolates of bluetongue virus

Bluetongue (BT) is an arthropod-borne viral disease affecting ruminants primarily in tropical and temperate regions of the world. Of the 24 serotypes of BT virus (BTV) identified worldwide, five have been found in the United States. Serotype identification of BTV isolates is important to the epidemiology of the virus, but current methods are cumbersome. A single-tube multiplex reverse transcriptase polymerase chain reaction (mRT-PCR) assay, previously developed for the serotype determination of U.S. BTV isolates, was evaluated. The determination of serotype was based on the size of the resultant amplified product. The procedure was evaluated using all 24 serotypes of BTV and nine serotypes of epizootic hemorrhagic disease virus (EHDV), a closely related orbivirus. Only the five U.S. serotypes of BTV were detected by the mRT-PCR. The assay was further tested using 132 BTV isolates originating from 24 western and southern states of the United States, from several different host species, spanning a period of 24 years. The serotypes of the isolates were determined by both a virus neutralization (VN) procedure and the mRT-PCR. Comparison of the mRT-PCR to the standard VN showed that the mRT-PCR successfully identified the serotypes of 130 of the isolates and was shown to be more reliable and specific than the VN assay.

The impact of bcl-2 expression and bax deficiency on prostate homeostasis in vivo

Prostatic glandular epithelial cells undergo apoptosis in response to androgen-deprivation. The molecular determinants of androgen-responsiveness in these cells are incompletely understood. Recent evidence suggests that bcl-2 gene family members may be important in this context. We used the probasin promoter to target a human bcl-2 transgene specifically to the prostate in order to assess its impact on conferring resistance to androgen withdrawal in, otherwise sensitive, prostatic glandular epithelial cells in vivo. We examined the contribution of bax to mediating androgen-responsiveness in prostatic glandular epithelial cells using bax knockout mice. The histologic appearance of the prostates from probasin-bcl-2 transgenic mice or bax-/- mice did not differ from those of control littermates. There was no evidence of hyperplastic or neoplastic growth. There was no difference between probasin bcl-2 transgenic mice, bax-/- mice, and control littermates in steady-state levels of apoptosis. Following castration our findings suggest that both bax and bcl-2 may each contribute to the androgen-responsiveness of prostatic glandular epithelial cells. It is apparent from these results, however, that bax is not required to mediate cell death in prostatic glandular epithelial cells following castration. A comparison between the apoptotic indices in the ventral prostate from the probasin-bcl-2 and bax-/- mice following castration suggests that the presence of bcl-2 may be a more important indicator of androgen-sensitivity than a deficiency of bax.

Telephone care as an adjunct to routine medical follow-up. A negative randomized trial

CONTEXT

In 1992, a randomized trial at one outpatient clinic demonstrated that making telephone appointments part of routine medical follow-up could save money and reduce hospitalization.

OBJECTIVE

To ascertain the effects of telephone care in other clinics.

DESIGN

Consenting patients of 20 physicians were randomly assigned to receive telephone care or usual care.

SETTING

Veterans Affairs General Medical Clinics in Denver, Colorado, and Sioux Falls, South Dakota.

PATIENTS

512 predominately male elderly veterans (mean age, 68 years) who had a broad range of chronic medical conditions.

INTERVENTION

At the intake clinic visit, the recommended revisit interval (e.g., return in 3 months) for telephone care patients was doubled (e.g., return in 6 months) and three intervening telephone appointments were scheduled. Three telephone appointments were also scheduled at all subsequent clinic visits.

MAIN OUTCOME MEASURES

Utilization of services and self-reported health status.

RESULTS

More than 2000 calls were made during the 2-year study period. Although the revisit interval was longer for telephone care patients after the intake visit (as was expected), it was the same for both telephone care and usual care patients after all subsequent visits, despite the scheduling of three telephone appointments for telephone care patients. The intervention had no effect on self-reported health status, hospital admission, or number of deaths. The intervention also had no effect on the total number of clinic visits, outpatient laboratory tests, or radiologic tests. Telephone care patients had fewer unscheduled visits than did usual care patients (2.0 vs. 2.8 visits/patient; P = 0.01).

CONCLUSION

Telephone care had little effect in this study. Instead of providing a way to maintain contact with patients without requiring them to appear in clinic frequently, telephone appointments became simply an additional service.

Building an idealized measurement system to improve clinical office practice performance

The aim of this article is to introduce key concepts and approaches for building a better practice-based measurement. Physicians are being challenged to produce measurably higher quality of services, lower costs, and better clinical outcomes to remain viable. In the absence of provider-driven practice improvements and independent measurement systems, office practices will remain dependent on performance data from external forces as drivers of change. Three key questions will be addressed in our pursuit of better measurement systems for continuous improvement and competitive advantage: (1) What do we want a measurement system to tell us in the first place? (2) What might an idealized measurement system look like if we had one? (3) What are some of the challenges that office practices face in closing the gap between building an idealized measurement system and the current state of office practice measurement?

Crystal structure of active site-inhibited human coagulation factor VIIa (des-Gla)

Factor VIIa (FVIIa) is a crucial haemostatic protease consisting of four distinct domains termed the Gla, epidermal growth factor-1 (EGF-1), EGF-2, and protease domains (from N- to C-terminus). The crystal structure of human FVIIa inhibited at the active site with 1, 5-dansyl-Glu-Gly-Arg-chloromethyl ketone and lacking the Gla domain has been solved to a resolution of 2.28 A. The EGF-2 and protease domains were well resolved, whereas no electron density for the EGF-1 domain was observed, suggesting a flexible arrangement or disorder within the crystal. Superposition of the protease domain of the present structure with that previously resolved in the tissue factor (TF)/FVIIai complex revealed that although overall the domain structures are similar, the EGF-2 domain is rotated by 7.5 degrees relative to the protease domain on binding TF. A single cleavage in the protease domain was found, between Arg315 and Lys316 (chymotrypsin numbering 170C-170D) in a FVII-specific insertion loop: this cleavage appeared to be essential for crystallisation. Insertion of the heavy chain N-terminal Ile153 is essentially identical in the two structures, as is the geometry of the active site residues and the inhibitor C-terminal arginine residue. Some differences are seen in the cleaved loop, but changes in TF-contact residues are generally minor. This structure supports the hypothesis that TF binding enables spatial domain arrangements in the flexible FVIIa molecule necessary for procoagulant function and furthermore that active site occupancy induces FVIIa active conformation via N-terminal insertion.

Streamlining nutritional care for the physician's office

OBJECTIVE

Nutritional care needs are overlooked in clinical practice. We review nutritional needs and describe an approach for improving nutritional care in clinical practice.

DESIGN

Data from a controlled trial and several population cohorts.

SETTING

Primary care practices and a population survey in New Hampshire and Vermont, USA.

SUBJECTS

The controlled trial involved 1651 persons aged 70+years. The cohorts include information from 1879 persons aged 12+.

INTERVENTION

All patients completed standard surveys which included information about nutritional needs. 22 practices participated in the trial.

RESULTS

The higher the BMI, the less healthy the population. 15 30% of patients report problems or concerns with eating/weight and nutrition. Patients with problems or concerns are often bothered by other health and social problems. Patients who have productive interactions with clinicians have improved nutritional care and are more likely to report help with eating problems (68% vs 86%; Odds ratio 5.0 (95% CI: 0.9-27.0).

CONCLUSIONS

Nutritional issues are common and complex. A productive provider-patient interaction can improve the nutritional care of patients. Essential elements for a productive interaction include an informed, educated patient and a provider (or clinical team) prepared to assess and manage the broad range of issues that are important to the patient. Technology facilitates necessary feedback between patient and provider.

Crystallization and preliminary X-ray analysis of active site-inhibited human coagulation factor VIIa (des-Gla)

Human coagulation factor VIIai that lacks the Gla domain (residues 1-44) has been prepared, purified, and crystallised. First, recombinant factor VII was activated to form factor VIIa, the active site was then inhibited with 1,5-dansyl-Glu-Gly-Arg-chloromethyl ketone, and finally the Gla domain was removed by chymotryptic digestion, yielding factor VIIai (des-Gla). After further purification single crystals suitable for x-ray analysis were obtained by vapour diffusion. Crystals of factor VIIai (des-Gla) belong to the tetragonal space group P41212 or P43212 with unit cell dimensions a = b = 94.85 A, c = 114.30 A, contain one molecule per asymmetric unit, and diffract to 2.3-A resolution when exposed to synchrotron radiation.

A computerized school-based health assessment with rapid feedback to improve adolescent health

Adolescent health problems are often undetected in physicians' offices. The Dartmouth Primary Care Cooperative Information Project has developed a validated and reliable approach to identify adolescent health problems and initiate education in a school setting. A self-administered, anonymous, 26-item questionnaire was given to 204 students in a rural high school. Responses were scanned into PC-based software. Within one working day students were given individualized letters identifying their problem health issues as detected by the questionnaire and recommendations for education. Ninety-nine percent of students participated. Six weeks later 49% of a sample of 41 students reported reading the information and 50% planned to change behavior. This standardized, validated strategy of adolescent health assessment, feedback, and education was feasible for use in schools. The school responded to the data by employing a psychologist to address mental health needs.

Development of a head and neck companion module for the quality of life-radiation therapy instrument (QOL-RTI)

PURPOSE/OBJECTIVE

A review of available head and neck quality of life (QOL) instruments reveals them to inadequately address important radiation related side effects, or to be too cumbersome for routine use. The purpose of this study was to develop a head and neck disease specific module as a companion to the previously developed quality of life - radiation therapy instrument (QOL-RTI). The goal was to create a more complete, yet concise, head and neck site-specific module geared toward patients receiving radiation therapy for head and neck cancer.

METHODS AND MATERIALS

This exploratory study included 34 consecutive patients undergoing definitive radiotherapy over a 6-7 week course (60-79.8 Gy). We developed and administered a 14-item questionnaire to all eligible patients treated with radiotherapy for head and neck cancer who were not already registered in another research study assessing quality of life (e.g., RTOG). During the treatment period, the QOL-RTI general tool and the head and neck (H&N) module were administered as follows: at baseline, at week four (for test-retest), and at the end of the treatment period. For validation purposes the QOL-RTI/H&N was compared to the functional assessment cancer tool head and neck (FACT-H&N) questionnaire. The FACT-H&N was administered one time at week 4, on the same day as the QOL-RTI/H&N. This report includes the treatment phase of the study (during the course of radiation).

RESULTS

Mean age was 62 years (range 40-75). Internal consistency of the module was satisfactory (Chronbach's alpha = 0.85). Test-retest yielded a correlation coefficient of 0.90 (p < 0.001). Concurrent validity, established by comparing the module to the FACT/H&N , yielded a correlation coefficient of 0.85. Significant changes in quality of life scores during a course of radiation was noted for both general quality of life tool and the site specific module. For the head and neck module, the difference in the mean baseline (7.17) and end of treatment scores (4.20) was 2.94, or 42% change (p < 0.0001). A smaller, yet still significant, difference in scores was seen in the general QOL tool (22 % change, p = 0.001). Item analysis of the module revealed statistically significant (p < 0.05) worsening in quality of life scores in the following areas: pain in throat, swallowing difficulty (meat/bread and liquids), changes in mucous and saliva, changes in taste, difficulty chewing, trouble with coughing, and speech difficulties. Items that were not significant were pain in the mouth, and appearance.

CONCLUSION

These initial results suggest that the H&N companion module to the QOL-RTI is a valid and reliable tool that is responsive to changes in QOL during a course of H&N radiation therapy. This tool differs from existing H&N tools by including specific assessments of mucous, saliva, taste, cough, and local pain in a concise format. Significant changes in QOL scores were noted in all of these items. Evaluation of the tool in the post-treatment period (follow-up) is ongoing.

The solution structure of human coagulation factor VIIa in its complex with tissue factor is similar to free factor VIIa: a study of a heterodimeric receptor-ligand complex by X-ray and neutron scattering and computational modeling

Factor VIIa (FVIIa) is a soluble four-domain plasma serine protease coagulation factor that forms a tight complex with the two extracellular domains of the transmembrane protein tissue factor in the initiating step of blood coagulation. To date, there is no crystal structure for free FVIIa. X-ray and neutron scattering data in solution for free FVIIa and the complex between FVIIa and soluble tissue factor (sTF) had been obtained for comparison with crystal structures of the FVIIa-sTF complex and of free factor IXa (FIXa). The solution structure of free FVIIa as derived from scattering data is consistent with the extended domain arrangement of FVIIa seen in the crystal structure of its complex with sTF, but is incompatible with the bent, less extended domain conformation seen in the FIXa crystal structure. The FVIIa scattering curve is also compatible with a subset of 317 possible extended structures derived from a constrained automated conformational search of 15 625 FVIIa domain models. Thus, the scattering data support extended domain models for FVIIa free in solution. Similar analyses showed that the solution scattering derived and crystal structures of the FVIIa-sTF complex were in good agreement. An automated constrained search for allowed structures for the complex in solution based on scattering curves showed that only a small family of compact models gave good agreement, namely those in which FVIIa and sTF interact closely over a large surface area. The general utility of this approach for structural analysis of heterodimeric complexes in solution is discussed. Analytical ultracentrifugation data and the modeling of these data were consistent with the scattering results. It is concluded that in solution FVIIa has an extended or elongated domain structure, which allows rapid interaction with sTF over a large surface area to form a high-affinity complex.

Coagulation factor VII Gln100 --> Arg. Amino acid substitution at the epidermal growth factor 2-protease domain interface results in severely reduced tissue factor binding and procoagulant function

We have used recombinant mammalian expression and purification of the factor VII (FVII) variant Gln100 --> Arg (Q100RFVII) to study FVII deficiency in subjects with this mutation. Q100RFVII was secreted poorly in comparison with wild-type FVII (WTFVII) in a stable mammalian expression system, and purified variant protein was found to have undetectable clotting activity. Following activation by immobilized factor Xa, Q100RFVIIa had amidolytic activity similar to WTFVIIa in the absence of soluble tissue factor (sTF); however, unlike WTFVIIa no typical increase in activity was seen after addition of sTF. In a factor X activation assay using relipidated transmembrane truncated tissue factor (residues 1-243), Q100RFVIIa showed less than 5% of the ability of WTFVIIa to activate factor X. We performed direct binding analysis of WT and Q100RFVII/FVIIa to immobilized sTF using surface plasmon resonance, and severely reduced binding of both non-activated and activated Q100RFVII to sTF was seen, indicating a pronounced defect in tissue factor (TF) interaction with this variant. In the sTF-FVIIa crystal structure the candidate residue Gln100 is not in contact with TF but is at the epidermal growth factor 2-protease domain interface. We suggest that the mutation results in a global fold change severely reducing tissue factor interaction; mutation of FVII residues not directly involved in the interaction with TF may still result in variant FVII unable to take part in the initiation of coagulation.

Release of carbon disulfide is a contributing mechanism in the axonopathy produced by N,N-diethyldithiocarbamate

The neurotoxicity of N,N-diethyldithiocarbamate (DEDC) is established, although the mechanisms responsible for its neurotoxicity are not. Previous experiments have demonstrated that DEDC has the ability to produce CS2-mediated protein cross-linking in vitro and that DEDC releases CS2 in vivo. The release of CS2 with subsequent cross-linking of proteins presents a potential mechanism through which DEDC may exert its neurotoxicity. In the present study DEDC (3 mmol/kg po) was given to rats every other day for 8 and 16 weeks. At the end of each treatment period, erythrocyte spectrin, hemoglobin, and spinal cord neurofilament preparations were isolated and examined for cross-linking using polyacrylamide gel electrophoresis, reverse phase HPLC, and Western blot techniques, respectively. Additional rats were perfused and sections of the lumbar and cervical spinal cord and the muscular branch of the posterior tibial nerve were removed and examined by light and electron microscopy. Relative to controls, significant levels of cross-linking were observed in all the proteins examined at both 8 and 16 weeks of treatment. Morphological changes were not detected at 8 weeks, but at 16 weeks degenerated and swollen axons filled with disorganized masses of neurofilaments were present in the distal regions of the long tracts of the lumbar and cervical spinal cord and also in the muscular branch of the posterior tibial nerve. The ability of DEDC to covalently cross-link proteins in vivo and to produce axonal structural changes identical to those produced by CS2 is consistent with release of CS2 from DEDC being a contributing mechanism in DEDC-induced neurotoxicity.

Treatment of liver injuries at level I and level II centers in a multi-institutional metropolitan trauma system. The Midwest Trauma Society Liver Trauma Study Group

OBJECTIVE

The development of trauma systems and trauma centers has had a major impact on the fate of the critically injured patient. However, some have suggested that care may be compromised if too many trauma centers are designated for a given area. As of 1987, the state of Missouri had designated six adult trauma centers, two Level I and four Level II, for the metropolitan Kansas City, Mo, area, serving a population of approximately 1 million people. To determine whether care was comparable between the Level I and II centers, we conducted a concurrent evaluation of the fate of patients with a sentinel injury, hepatic trauma, over a 6-year period (1987-1992) who were treated at these six trauma centers.

METHODS

All patients during the 6-year study period who suffered liver trauma and who survived long enough to be evaluated by computerized tomography or celiotomy were entered into the study. Patients with central nervous system trauma were excluded from analysis. Information concerning mechanism of injury, RTS, Injury Severity Score (ISS), presence of shock, liver injury scoring, mode of treatment, mortality, and length of stay were recorded on abstract forms for analysis. Care was evaluated by mortality, time to the operating room (OR), and intensive care unit (ICU) and hospital length of stay.

RESULTS

Over the 6-year period 300 patients with non-central nervous system liver trauma were seen. Level I centers cared for 195 patients and Level II centers cared for 105. There was no difference in mean ISS or ISS > 25 between Level I and II centers. Fifty-five (28%) patients arrived in shock at Level I centers and 24 (23%) at Level II centers. Forty-eight patients (16%) died. Thirty-two (16%) died at Level I centers, and 16 (15%) died at Level II centers. Twenty of 55 patients (36%) in shock died at Level I centers, and 11 of 24 (46%) died at Level II centers (p = 0.428). Forty-three patients (22%) had liver scaling scores of IV-VI at Level I centers, and 10 (10%) had similar scores at Level II centers (p < 0.01). With liver scores IV-VI, 22 of 43 (51%) died at Level I centers and 10 of 14 (71%) died at Level II centers (p = 0.184). There was no difference in mean time or in delays beyond 1 hour to the OR for those patients in shock between Level I and II centers. There was a longer ICU stay at Level II centers (5.0 +/- 8.3 vs. 2.8 +/- 8.4 days, p = 0.04). This difference was confined to penetrating injuries. There was no difference in hospital length of stay.

CONCLUSIONS

In a metropolitan trauma system, when Level I and II centers were compared for their ability to care for victims of hepatic trauma, there was no discernible difference in care rendered with respect to severity of injury, mortality, delays to the OR, or hospital length of stay. It was observed that more severe liver injuries were seen at Level I centers, but this did not seem to significantly affect care at Level II centers. There was a longer ICU stay observed at Level II centers owing to penetrating injuries, possibly because there were fewer penetrating injuries treated at these facilities. Although the bulk of patients were seen at Level I centers, care throughout the system was equivalent.

A replicable and customizable approach to improve ambulatory care and research

Health care is a service industry. A fundamental attribute of many successful service industries is the "small replicable unit (SRU)." There are three essential elements of an SRU: (1) the smallest core unit of activity, (2) micromeasures designed to help manage the core activities, and (3) combinations of the activities and measures to match local customer needs. In this article, we describe a model for geriatric care based on "SRU thinking." We demonstrate how this approach places measurement of patient values, clinical improvement strategies, and research objectives into day-to-day health care delivery.

Sex differences in the effectiveness of elaborative strategy use: knowledge access comparisons

Dual-task procedures-elaborative strategy use and finger-tapping-were used to examine both recall and mental effort demands of elaboration strategy use with equal numbers of boys and girls at grades two and three. Knowledge-base access was examined by comparing different item types in the associative learning list: masculine, feminine, and mixed. Results showed that boys and girls did not differ in their recall of arbitrarily paired items (e.g., mixed pairs). A Sex by Item Type (masculine vs feminine) interaction, however, revealed that for feminine pairs girls recalled more than boys, whereas for masculine pairs no sex difference was observed. Finger tapping interference scores indexed mental effort. Similar to the recall findings, results indicated that the elaboration of feminine pairs required less mental effort by girls in contrast to boys. Elaboration of masculine pairs was not associated with a sex difference. The results were discussed in terms of sex differences in knowledge-base access.

The measurement of 2-thiothiazolidine-4-carboxylic acid as an index of the in vivo release of CS2 by dithiocarbamates

Dithiocarbamates and their disulfides are used extensively as agricultural fungicides, as accelerators of the vulcanization process of rubber in industry, and as therapeutic agents in medicine. The widespread uses of these compounds in agriculture, industry, and medicine provide many avenues of exposure to the human population. Subchronic to chronic exposures to some dithiocarbamates have resulted in the development of neuropathy in humans and experimental animals. Decomposition to CS2 presents a potential mechanism through which the toxicity of dithiocarbamates may be mediated. The purpose of this study was to determine the potential of dithiocarbamates to release CS2 in vivo. The ability to release CS2 was assessed by measuring urinary 2-thiothiazolidine-4-carboxylic acid (TTCA), which is used in industry to measure the exposure of workers to CS2. In this study, rats were housed individually in metabolic cages and given daily equimolar ip or po doses (1.5 mmol/kg) of N,N-diethyldithio-carbamate (DEDC), disulfiram (DS), N-methyldithiocarbamate (NMDC), or CS2 for 5 days, and TTCA was measured in urine collected at 24 h intervals. For each compound administered, TTCA was produced in all of the treated animals and the amount of TTCA eliminated in urine from po administration was significantly greater than that from ip administration. The relative rates of TTCA elimination in urine were DS > DEDC approximately equal to CS2 > NMDC for both routes of administration. Following administration of N,N-diethyl[13C = S] dithiocarbamate, carbon-13 enrichment at the thiocarbonyl carbon of TTCA was demonstrated using 13C NMR. Analysis of urinary TTCA proved to be useful both for establishing the in vivo release of CS2 by dithiocarbamate containing compounds and for evaluating the bioavailability of CS2. The results appear especially relevant to disulfiram, which is given orally for sustained periods in the treatment of alcoholism and has resulted in the development of neuropathy in susceptible individuals.

Decreased elastin synthesis in normal development and in long-term aortic organ and cell cultures is related to rapid and selective destabilization of mRNA for elastin

We have previously shown that aortic organ cultures from 1- to 3-day-old chickens initially mimic the high levels of elastin production seen in vivo. However, more prolonged incubation of these tissues results in decreased synthesis of elastin. In the present study, we demonstrate that decreased production of elastin in these aortic organ cultures is selective for elastin compared with collagen and is correlated with decreased steady state levels of mRNA for elastin. These decreases in steady state levels of elastin mRNA are due at least in part to a rapid and selective destabilization of mRNA for elastin, the half-life of which falls from approximately 25 hours in fresh aortic tissues to approximately 15 hours after incubation for only 8 hours. Destabilization of elastin mRNA can be prevented by incubation in the presence of blockers of DNA transcription (5,6-dichlorobenzimidazole riboside and actinomycin D) and mRNA translation (cycloheximide). Furthermore, the half-life of aortic elastin mRNA decreases from approximately 25 hours in the 1-day-old chicken to approximately 7 hours in the 8-week-old chicken, demonstrating that destabilization of mRNA is an important contributing factor in the decline in production of aortic elastin taking place during normal postnatal growth.

Factor VIIa and the extracellular domains of human tissue factor form a compact complex: a study by X-ray and neutron solution scattering

The four-domain structure of human factor VIIa and the two-domain structure of tissue factor form a tight complex to initiate blood coagulation. By solution scattering, the mean X-ray and neutron radii of gyration RG (which determine macro-molecular elongation) were found to be 3.25 nm, 2.13 nm and 3.14 nm (+/- 0.13 nm) for factor VIIa, the extracellular region of tissue factor and their complex in that order. The mean cross-sectional radii of gyration RXS were 1.33 nm, 0.56 nm and 1.42 nm (+/- 0.13 nm) in that order. The mean lengths were 10.3 nm, 7.7 nm and 10.2 nm in that order. The data show that, in solution, the free proteins have extended domain structures, and the complex is formed by a compact side-by-side alignment of the two proteins along their long axes. The high binding affinity of tissue factor for factor VIIa may thus be accounted for by the occurrence of many intermolecular contacts in the complex.

Characterization of mutations within the factor VIII gene of 73 unrelated mild and moderate haemophiliacs

To screen for mutations within the factor VIII gene of 101 patients (85 unrelated), we used denaturing gradient gel electrophoresis (DGGE) after DNA amplification of target regions, including all coding regions except for the middle part (amino acid 757 to amino acid 1649) of the B domain. With this method, missense mutations were identified in 86% of unrelated patients. 41 different mutations were identified: 25 of them have not been described previously. Five of the genotypes are associated with CRM+ and 26 with CRMred status. Patients who are definitely related to each other showed no differences in DNA sequence. One patient showed two different base pair alterations, the first at amino acid 469 [ala(GCA-->gly(GGA)] and the second at position 473 [tyr(TAT)-->cys(TGT)]. One patient with an amino acid change at position 1689 [arg(CGC)-->his(CAC)] has developed an inhibitor against factor VIII.

Out-of-hospital ventilation: bag--valve device vs transport ventilator

OBJECTIVE

To examine the patterns of out-of-hospital airway management and to compare the efficacy of bag-valve ventilation with that of the use of a transport ventilator for intubated patients.

METHODS

A prospective, nonrandomized, convenience sample of 160 patients requiring airway management in the out-of-hospital urban setting was analyzed. A survey inquiring about airway and ventilatory management was completed by emergency medical services (EMS) personnel, and arterial blood gas (ABG) samples were obtained within 5 minutes of patient arrival in the ED. The ABG parameters were compared for patients grouped by different airway techniques and presence or absence of cardiac arrest (systolic blood pressure < 50 mm Hg) upon ED presentation.

RESULTS

Over a one-year period, 160 surveys were returned. The majority (62%) of the patients were men; the population mean age was 61 +/- 19 years. Presenting ABGs were obtained for 76 patients; 17% (13/76) had systemic perfusion and 83% (63/76) were in cardiac arrest. There was no difference in ABG parameters between the intubated cardiac arrest patients ventilated with a transport ventilator (pH 7.17 +/- 0.17, PaCO2 37 +/- 20 torr, and PaO2 257 +/- 142 torr) and those ventilated with a bag-valve device (pH 7.20 +/- 0.16, PaCO2 42 +/- 21 torr, and PaO2 217 +/- 138 torr). The patients ventilated via an esophageal obturator airway (EOA) device had impaired gas exchange, compared with the groups who had endotracheal (ET) intubation (pH 7.09 +/- 0.13, PaCO2 76 +/- 30 torr, and PaO2 75 +/- 35 torr). The intubated patients not in cardiac arrest had similar ABG parameters whether ventilated manually with a bag-valve device or with a transport ventilator. Endotracheal intubation was successfully accomplished in 93% (123/132) of attempted cases.

CONCLUSIONS

In this sample, ET intubation was the most frequently used airway by EMS providers. When ET intubation was accomplished, adequate ventilation could be achieved using either bag-valve ventilation or a transport ventilator. Ventilation via the EOA proved inadequate.

Protein-bound pyrroles in rat hair following subchronic intraperitoneal injections of 2,5-hexanedione

Studies were initiated to ascertain whether body hair could be used to develop a biological marker for chronic exposure to industrial neurotoxicants that yield the metabolite 2,5-hexanedione (2,5-HD), that is, n-hexane and methyl n-butyl ketone. Rats were injected daily with a 50 mg/kg ip dose of 2,5-HD for 45 d. At intervals, body hair and individual vibrissae were removed (under general anesthesia) and tested for the presence of pyrrole substances with p-N,N-dimethylaminobenzaldehyde (DMAB, Ehrlich's reagent). Vibrissae and body hair were stained a reddish color that was distinctly different from that observed with the hair taken from control animals. Solubilized body hair protein from the treated animals gave a positive Ehrlich's test, while that from control animals was negative. Spectral analysis of the DMAB-treated hair from experimental animals disclosed a maximum absorbance at 530 nm, which indicated the presence of pyrrole substituents. Serial analysis of individual nose hairs taken during 2,5-HD administration showed a progression with time of the region staining positively for pyrroles, thus indicating that the process can proceed in growing hair. These findings suggest the potential utility of hair as an indicator for chronic exposure to this class of industrial chemicals possessing neurotoxicity potential. This could complement urinary analysis, which is now used to confirm recent exposure.

An overview of learning disabilities: psychoeducational perspectives

In general, people with learning disabilities are a heterogeneous population that require a multidisciplinary evaluation and careful, well-planned intervention. Despite this heterogeneity, patterns of problems often co-occur. Therefore, diagnosticians and educators should look beyond single areas of achievement such as reading or arithmetic. In addition, problems in one area of learning typically have secondary impacts on higher levels of learning. That is, comprehension problems typically interfere with expression. Every effort should be made to examine patterns of problems and to avoid fragmentation of services so that each area of underachievement is not treated separately. Although learning disabilities usually interfere with school performance, they are not simply academic handicaps. They interfere with certain social activities as well as occupational pursuits. In many instances, they impact on mental health and self-esteem. Therefore, students need multiple services. And, as emphasized throughout this journal issue, learning disabled individuals may have comorbid conditions such as attention deficit disorder, depression, and neurologic problems. Furthermore, the problems may change over time. Children may first be identified because of language comprehension problems but later have reading or mathematics difficulty. With intervention, oral expressive problems may be alleviated but may be manifested later in written language.

Surface plasmon resonance studies of the interaction between factor VII and tissue factor. Demonstration of defective tissue factor binding in a variant FVII molecule (FVII-R79Q)

The blood coagulation cascade is initiated when vessel injury allows factor VII (FVII) to form a complex with tissue factor (TF). Complete deficiency of FVII causes a lethal bleeding diathesis, but individuals with moderately reduced FVII levels are often asymptomatic. Some of these individuals have circulating partially functional FVII, as a result of point missense mutations in critical parts of the molecule. One such mutation has been reported at position 79 in the first epidermal growth factor-like (EGF) domain of FVII, where an arginine residue has been replaced by glutamine. There is controversy as to whether or not this mutation reduces the affinity of the FVII/TF interaction compared to wild-type FVII. To address this problem, we have expressed recombinant FVII-R79Q and subjected it to detailed biochemical analysis. One-stage FVII:C assays show the variant FVII to have reduced activity with respect to the wild type. Rates of autoactivation and activation by FXa to the two-chain molecule were identical for wild-type and variant FVII. The Vmax for FX activation was lower for the mutant as measured using an amidolytic assay for FX activity. In contrast, the Km for FX was lower for the variant than the wild-type molecule. Peptidyl substrate hydrolysis was virtually identical for both variant and normal FVIIa in the presence and absence of TF. The variant has reduced affinity for TF as measured by surface plasmon resonance. FVII-R79Q has an association rate constant (kassoc) one-fifth of that of normal FVII, but a similar kdiss, resulting in a decrease in the affinity of the enzyme for its cofactor.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of pressure and flow triggering systems during continuous positive airway pressure

STUDY OBJECTIVE

Compare the inspiratory work of breathing (WOBI) during pressure triggering (PT), and flow triggering (FT) using two microprocessor ventilators.

DESIGN

A randomized, crossover comparison of triggering strategies and ventilators used.

SETTING

Surgical intensive care unit.

PATIENTS

Ten patients recovering from acute respiratory failure (eight men, two women; mean age, 48 +/- 12 years) breathing on continuous positive airway pressure (CPAP) of 5 cm H2O were studied.

INTERVENTIONS

Patients were randomly assigned to either receive 5 cm H2O CPAP via one of two units (Hamilton Veolar or Puritan Bennett 7200ae) using either PT or FT. Each patient had 30-min trials using the following: (1) Veolar FT; (2) Veolar PT; (3) 7200ae FT; and (4) 7200ae FT.

MEASUREMENTS AND RESULTS

During each trial period, work of breathing (WOB) and pressure time product (PTP) were measured using a respiratory monitor (Bi-core CP-100). All patients were placed in semi-Fowler position and esophageal balloons were inserted and their position confirmed using the occlusion technique. Continuous measurements of peak negative pressure during inspiration, tidal volume (VT), minute ventilation (VE), respiratory frequency (f) were accomplished with a flow transducer at the proximal airway. FT with the 7200ae was superior to PT as measured by both the WOB (0.58 +/- 0.3 vs 0.84 +/- 0.2 J/L, p < 0.01) and PTP (148 +/- 50 vs 206 +/- 41 cm H2O/s/min, p, 0.05). FT with the Veolar was also superior to PT with respect to the WOB (0.53 +/- 0.2 vs 0.93 +/- 0.2 J/L, p < 0.01) and PTP (140 +/- 39 vs 229 +/- 46 cm H2O/s/min, p < 0.05).

CONCLUSION

FT reduces the WOB compared with PT, regardless of the ventilator used. The reduction in WOB during FT is related to improved responsiveness and changes in the posttrigger phase.

A pilot study of patient quality of life during radiation therapy treatment

The purpose of this research was to develop a quality of life (QOL) tool that would help to reveal any physical, mental or emotional changes patients may experience while receiving radiation therapy. Research focusing on quality of life during radiation therapy is in its infancy. Although many tools to measure QOL have been developed, until very recently few had been geared specifically toward those receiving radiation therapy. In addition to a radiation-specific instrument, the goal was to develop a multidimensional measure that would be short in length and could be completed by the patient in 15 min or less. This new Quality of Life Radiation Therapy Instrument (QOL-RTI) is a visual analogue scale with 24 questions and is not site specific. Twenty-one patients with various diagnoses and treatment sites completed the questionnaire at baseline and then weekly during the course of radiation therapy. The internal consistency of the instrument (Cronbach's alpha) was 0.87. At baseline each patient also was asked to complete the Ferran's and Powers QLI Cancer Version 6 (QLIC); the correlation between the QLIC and the QOL-RTI was 0.47. These results are based on a small number of patients, but initial efforts in creating an instrument that is quick and easy for patients to complete have been encouraging. An additional 70-80 patients are now being entered into a study using the QOL-RTI to further evaluate reliability and validity.

Factor VIII S373L: mutation at P1' site confers thrombin cleavage resistance, causing mild haemophilia A

A novel CRM+ mutation, factor VIII position 373 serine to leucine substitution (FVIII 373-Leu) was identified during a survey of Factor VIII (FVIII) mutations. We have purified the variant protein from the patient's plasma in order to allow further characterisation of the molecule. The CRM+ plasma contained 120% Factor VIII antigen (FVIII:Ag) and 6% Factor VIII coagulant activity (FVIII:C). After purification the mutant FVIII was subjected to thrombin proteolysis, and was thereby activated 5.6-fold compared with 7-fold for wild type molecule. Subsequently, spontaneous inactivation of the mutant was much slower than noted for wild type FVIII. Western blot analysis using monoclonal antibodies demonstrated that thrombin cleavage of FVIII 373-Leu at positions 740 and 1689 were normal but that cleavage at position 372 was completely absent. Crystallographic coordinates of the active site of thrombin complexed to fibrinopeptide A were used to explore possible mechanistic reasons for the failure of thrombin to cleave the mutant FVIII at position 372. Steric hindrance between the mutant side chain and the side chain of the P1 residue was apparent. We conclude that the functional defect of FVIII 373-Leu results from the inability of thrombin to cleave the mutant at position 372-373, and propose that this is due to steric hindrance by the side chain of leucine 373, preventing correct formation of the enzyme substrate complex.