Thrombolytics in Cardiac Arrest from Pulmonary Embolism: A Systematic Review and Meta Analysis

BACKGROUND

During cardiopulmonary resuscitation, intravenous thrombolytics are commonly used for patients whose underlying etiology of cardiac arrest is presumed to be related to pulmonary embolism (PE).

METHODS

We performed a systematic review and meta-analysis of the existing literature that focused on the use of thrombolytics for cardiac arrest due to presumed or confirmed PE. Outcomes of interest were return of spontaneous circulation (ROSC), survival to hospital discharge, neurologically-intact survival, and bleeding complications.

RESULTS

Thirteen studies with a total of 803 patients were included in this review. Most studies included were single-armed and retrospective. Thrombolytic agent and dose were heterogeneous between studies. Among those with control groups, intravenous thrombolysis was associated with higher rates of ROSC (OR 2.55, 95% CI = 1.50-4.34), but without a significant difference in survival to hospital discharge (OR 1.41, 95% CI = 0.79-2.41) or bleeding complications (OR 2.21, 0.95-5.17).

CONCLUSIONS

Use of intravenous thrombolytics in cardiac arrest due to confirmed or presumed PE is associated with increased ROSC but not survival to hospital discharge or change in bleeding complications. Larger randomized studies are needed. Currently, we recommend continuing to follow existing consensus guidelines which support use of thrombolytics for this indication.

Predictors of Inpatient Morbidity and Mortality After 1- and 2-Level Anterior Cervical Diskectomy and Fusion Based on the National Inpatient Sample Database From 2006 Through 2010

Spine procedures, including anterior cervical diskectomy and fusion (ACDF), are more commonly being performed in an outpatient setting to maximize value. Early complications after ACDF are rare but can have devastating consequences. The authors sought to determine risk factors for inpatient complications after 1-and 2-level ACDF by performing a retrospective review of the National Inpatient Sample (NIS) administrative database from 2006 through 2010. A total of 78,771 patients were identified. Multivariate logistic regression analysis was performed to identify preoperative risk factors for medical and surgical complications, including mortality, airway compromise, new neurologic deficit, and surgical-site infection. Inpatient mortality and overall complication rates were 0.074% and 3.73%, respectively. The risk of any medical complication was 3.13%. Airway compromise, neurologic deficit, and surgical-site infection occurred in 0.75%, 0.05%, and 0.04% of cases, respectively. Chronic kidney disease was the strongest predictor of mortality, with an odds ratio (OR) of 11.14 (P<.001). Airway complication was associated with age older than 65 years, male sex, myelopathy, diabetes mellitus, anemia, bleeding disorder, chronic obstructive pulmonary disease, obesity, and obstructive sleep apnea (P<.05). Preoperative diagnosis of myelopathy was most strongly associated with an increased rate of neurologic complication (OR, 6.67; P<.001). Anemia was associated with a significantly increased rate of surgical-site infection, with an OR of 14.34 (P<.001). Age older than 65 years; certain medical comorbidities, particularly kidney disease and anemia; and a preoperative diagnosis of myelopathy are associated with increased risk of early complication following ACDF surgery. Surgeons should consider these risk factors when deciding to perform ACDF surgery in an outpatient setting. [Orthopedics. 2021;44(5):e675-e681.].

Age Does Not Predict Failure to Rescue Following Resuscitative Thoracotomy in Penetrating Trauma

BACKGROUND

The limitations of resuscitative thoracotomy (RT) after penetrating trauma have been well documented, but there is a paucity of data on the effect age has on mortality. This begs the question as to the utility of RT in an aging patient population. We investigate the significance of age as a predictor for failure to rescue after RT in penetrating trauma.

OBJECTIVE

We sought to identify whether chronologic age has a measurable effect on rates of failure to rescue after RT.

METHODS

We performed a retrospective cohort analysis using the Trauma Quality Improvement Program from 2011 to 2015 including all pulseless patients undergoing RT after penetrating injury. Our primary outcome was failure to rescue defined as death in the emergency department after RT. Multivariate analyses were performed to identify the relationship between age and morality controlling for injury severity.

RESULTS

One thousand one hundred twelve RTs were performed during the study period with an overall failure to rescue rate of 61.8% (n = 687) within the emergency department and an in-hospital mortality rate of 96.9%, which is in line with national data. On univariate analysis, there was no significant association between age and mortality (p = 0.44). On multivariate analysis examining the interaction between age and mortality adjusting for injury severity, we found that chronologic age was not an independent predictor of death after RT.

CONCLUSIONS

Age does not appear to be an independent predictor of failure to rescue after RT in penetrating trauma and should not be a sole determinant in procedural decision making.

COVID-19 Intubation Safety: A Multidisciplinary, Rapid-Cycle Model of Improvement

The COVID-19 pandemic has forced the health care industry to develop dynamic protocols to maximize provider safety as aerosolizing procedures, specifically intubation, increase the risk of contracting SARS-CoV-2. The authors sought to create a quality improvement framework to ensure safe practices for intubating providers, and describe a multidisciplinary model developed at an academic tertiary care facility centered on rapid-cycle improvements and real-time gap analysis to track adherence to COVID-19 intubation safety protocols. The model included an Intubation Safety Checklist, a standardized documentation template for intubations, obtaining real-time feedback, and weekly multidisciplinary team meetings to review data and implement improvements. This study captured 68 intubations in suspected COVID-19 patients and demonstrated high personal protective equipment compliance at the institution, but also identified areas for process improvement. Overall, the authors posit that an interdisciplinary workgroup and the integration of standardized processes can be used to enhance intubation safety among providers during the COVID-19 pandemic.

The cost of implanting a cemented versus cementless total knee arthroplasty

Aims

The aim of this study was to compare the actual cost of a cemented and cementless total knee arthroplasty (TKA) procedure.

Materials and Methods

The cost of operative time, implants, cement, and cementing accessories were included in the overall cost of the TKA procedure. Operative time was determined from a previously published study comparing cemented and cementless implants of the same design. The cost of operative time, implants, cement, and cementing accessories was determined from market and institutional data.

Results

Mean operative time for cemented TKA was 11.6 minutes longer for cemented TKA than cementless TKA (93.7 minutes (sd 16.7) vs 82.1 minutes (sd 16.6); p = 0.001). Using a conservative published standard of $36 per minute for operating theatre time cost, the total time cost was $418 higher for cementing TKA. The cost of cement and accessories ranged from $170 to $625. Overall, the calculated cost of cemented TKA is $588 to $1043, depending on technique. The general increased charge for cementless TKA implants over cemented TKA implants was $366.

Conclusion

The overall procedural cost of implanting a cementless TKA is less than implanting a cemented TKA. Cost alone should not be a barrier to using cementless TKA. Cite this article: Bone Joint J 2019;101-B(7 Supple C):61–63

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Combining Wireless Technology and Behavioral Economics to Engage Patients (WiBEEP) with cardiometabolic disease: a pilot study

Background

The long-term management of cardiometabolic diseases, such as type 2 diabetes and hypertension, is complex and can be facilitated by supporting patient-directed behavioral changes. The concurrent application of wireless technology and personalized text messages (PTMs) based on behavioral economics in managing cardiometabolic diseases, although promising, has not been studied. The aim of this pilot study was to evaluate the feasibility and acceptability of the concurrent application of wireless home blood pressure (BP) monitoring (as an example of “automated hovering”) and PTMs (as an example of “nudging”) targeting pharmacotherapy and lifestyle habits in patients with cardiometabolic disease (type 2 diabetes and/or hypertension).

Methods

The Wireless Technology and Behavioral Economics to Engage Patients (WiBEEP) with cardiometabolic disease study was a single-arm, open-label, 7-week-long pilot study in 12 patients (mean age 58.5 years) with access to a mobile phone. The study took place at Tufts Medical Center (Boston, MA) between March and September 2017. All patients received PTMs; nine patients received wireless home BP monitoring. At baseline, patients completed questionnaires to learn about their health goals and to assess medication adherence; at the end of week 7, all patients completed questionnaires to evaluate the feasibility and acceptability of the intervention and assess medication adherence. Hemoglobin A1c was ascertained from data collected during routine clinical care in 7 patients with available data.

Results

The majority of patients reported the text messages to be easy to understand (88%) and appropriate in frequency (71%) and language (88%). All patients reported BP monitoring to be useful. Mean arterial pressure was lower at the end-of-study compared to baseline (− 3.4 mmHg [95% CI, − 5 to − 1.8]. Mean change in hemoglobin A1c was − 0.31% [95% CI, − 0.56 to − 0.06].

Conclusions

Among patients with cardiometabolic disease, the combination of wireless BP monitoring and lifestyle-focused text messaging was feasible and acceptable. Larger studies will determine the long-term effectiveness of such an approach.

Proteomic analysis of JAK2V617F-induced changes identifies potential new combinatorial therapeutic approaches

In excess of 90% of patients with polycythaemia vera (PV) express a mutated form of Janus kinase 2 (JAK2), JAK2V617F. Such aberrant proteins offer great potential for the treatment of these diseases; however, inhibitors to JAK2 have had limited success in the clinic in terms of curing the disease. To understand the effects of this oncogene in haematopoietic cells with the aim of improving treatment strategies, we undertook a systematic evaluation of the effects of JAK2V617F expression using proteomics. The effects of JAK2V617F on over 5000 proteins and 2000 nuclear phosphopeptide sites were relatively quantified using either SILAC or eight-channel iTRAQ mass spectrometry. Pathway analysis of the proteins identified as changing indicated disruption to the p53 and MYC signalling pathways. These changes were confirmed using orthogonal approaches. The insight gained from this proteomic analysis led to the formation of hypothesis-driven analysis on inhibitor-mediated effects on primary cells from patients with a JAK2V617F mutation. Simultaneous inhibition of MYC and upregulation of p53 led to the preferential extinction of JAK2V617F-positive CD34+ cells, illustrating a potential therapeutic benefit from combined targeting of p53 and MYC.

ADAM-17: a novel therapeutic target for triple negative breast cancer

BACKGROUND

Validated targeted therapy is currently unavailable for patients with invasive breast cancer negative for oestrogen receptors, progesterone receptors and HER2 [i.e., those with triple-negative (TN) disease]. ADAM-17 is a protease involved in the activations of several ligands that bind to and promotes intracellular signalling from the EGFR/HER family of receptors.

PATIENTS AND METHODS

Expression of ADAM-17 was measured in 86 triple-negative and 96 non-triple-negative breast cancers. The ADAM-17 specific inhibitor, PF-5480090 (TMI-002, Pfizer) was tested in a panel of breast cancer cell lines for effects on functional outputs.

RESULTS

In this study we show using both Western blotting and immunohistochemistry that ADAM-17 is expressed at significantly higher levels in TN than non-TN breast cancers. Using a panel of breast cancer cell lines in culture, PF-5480090 was found to decrease release of the EGFR ligand, TGF-alpha, decrease levels of phosphorylated EGFR and block cell proliferation in a cell-type-dependent manner. Potentially important was the finding of a significant and moderately strong correlation between ADAM-17 activity and extent of proliferation inhibition by PF-5480090 (r = 0.809; p = 0.003; n = 11). Pretreatment of cell lines with PF-5480090 enhanced response to several different cytotoxic and anti-EGFR/HER agents.

CONCLUSION

It is concluded that inhibition of ADAM-17, especially in combination with chemotherapy or anti-EGFR/HER inhibitors, may be a new approach for treating breast cancer, including patients with TN disease.

Extracellular signal-regulated kinase 1 and 2 are not required for GnRH neuron development and normal female reproductive axis function in mice

BACKGROUND/AIMS

Selective deletion of extracellular signal-regulated kinase (ERK) 1 and ERK2 in the pituitary gonadotrope and ovarian granulosa cells disrupts female reproductive axis function. Thus, we asked if ERK1 and ERK2 are critical for GnRH neuron ontogeny or the central control of female reproductive function.

METHODS

GnRH-Cre-recombinase (Cre+) expressing mice were crossed with mice with a global deletion of ERK1 and a floxed ERK2 allele (Erk1-/Erk2fl/fl) to selectively delete ERK2 in GnRH neurons.

RESULTS

Cre-recombinase mRNA was selectively expressed in the brain of Cre+ mice. GnRH neuron number and location were determined during embryogenesis and in the adult. GnRH neuron counts at E15 did not differ between experimental and control groups (1,198 ± 65 and 1,160 ± 80 respectively, p = NS). In adults, numbers of GnRH neurons in the GnRHCre+Erk1-/Erk2- mice (741 ± 157) were similar to those in controls (756 ± 7), without alteration in their distribution across the forebrain. ERK1 and 2 deficiency did not alter the timing of vaginal opening, age at first estrus, or estrous cyclicity.

CONCLUSIONS

Although ERK1 and 2 are components of a dominant signaling pathway in GnRH neuronal cells that modulates survival and control of GnRH gene expression, other signaling pathways compensate for their deletion in vivo to allow GnRH neuron survival and targeting and normal onset of female sexual maturation and reproductive function. In contrast to effects at the pituitary and the ovary, ERK1 and ERK2 are dispensable at the level of the GnRH neuron.

mTOR in breast cancer: differential expression in triple-negative and non-triple-negative tumors

Triple-negative breast cancer (TNBC) is defined by the absence of estrogen receptors (ER), progesterone receptors (PR) and overexpression of HER2. Targeted therapy is currently unavailable for this subgroup of breast cancer patients. mTOR controls cancer cell growth, survival and invasion and is thus a potential target for the treatment of patients with TNBC. Using immunohistochemistry, mTOR and p-mTOR were measured in 89 TNBCs and 99 non-TNBCs. While mTOR expression was confined to tumor cell cytoplasm, p-mTOR staining was located in the nucleus, perinuclear area and in the cytoplasm. Potentially important, was our finding that nuclear p-mTOR was found more frequently in triple-negative than non triple-negative cancers (p < 0.001). These results suggest that mTOR may play a more important role in the progression of TNBC compared to non-TNBC. Based on these findings, we conclude that mTOR may be a new target for the treatment of triple-negative breast cancer.

Proteomic analysis reveals a novel mechanism induced by the leukemic oncogene Tel/PDGFRβ in stem cells: activation of the interferon response pathways

Objective proteomic analysis offers opportunities for hypothesis generation on molecular events associated with pathogenesis in stem cells. Relative quantification mass spectrometry was employed to identify pathways affected by Tel/PDGFRβ, an oncogene associated with myeloproliferative neoplasia (MPN). Its effects on over 1800 proteins were quantified with high confidence. Of those up-regulated by Tel/PDGFRβ several were involved in the interferon gamma (IFNγ) response. To validate these observations we employed embryonic and myeloid stem cells models which revealed Tel/PDGFRβ-induced STAT1 up-regulation and activation was responsible for modulating the interferon response. A STAT1 target highly up-regulated was ICSBP, a transcriptional regulator of myeloid and eosinophilic differentiation. ICSBP interacts with CBP/p300 and Ets transcription factors, to promote transcription of additional genes, including the Egr family, key regulators of myelopoiesis. These interferon responses were recapitulated using IFNγ stimulation of stem cells. Thus Tel/PDGFRβ induces aberrant IFN signaling and downstream targets, which may ultimately impact the hematopoietic transcriptional factor network to bias myelomonocytic differentiation in this MPN.

Harmonisation of multi-centre real-time reverse-transcribed PCR results of a candidate prognostic marker in breast cancer: an EU-FP6 supported study of members of the EORTC - PathoBiology Group

AIM

Assessment of intra- and inter-laboratory variation in multi-centre real-time reverse-transcribed PCR (qRT-PCR)-based mRNA quantification of a prognostic marker in breast cancer using external quality assurance (EQA).

METHODS

A questionnaire on the methodologies used and EQA calibrators were sent to 5 participating laboratories from 4 European countries, which measured mRNA levels of PITX2 splice variants and reference genes by qRT-PCR.

RESULTS

Differences in the methodology included PCR quantification methodology and equipment, RNA extraction and cDNA synthesis procedures. The intra-laboratory coefficient of variation (CV) ranged from 5 to 23%, and the inter-laboratory CV ranged from 17 to 30%. The inter-laboratory CV was reduced to 13% by using prediluted calibrators and by harmonising the data in the central QA laboratory. Additional normalisation using reference genes did not decrease the variation further.

CONCLUSIONS

Both externally provided calibrators and centralised harmonisation are required to reduce the intra-laboratory variation in multi-centre qRT-PCR results to an acceptable level.

Previtellogenic oocyte growth in salmon: relationships among body growth, plasma insulin-like growth factor-1, estradiol-17beta, follicle-stimulating hormone and expression of ovarian genes for insulin-like growth factors, steroidogenic-acute regulatory protein and receptors for gonadotropins, growth hormone, and somatolactin

Body growth during critical periods is known to be an important factor in determining the age of maturity and fecundity in fish. However, the endocrine mechanisms controlling oogenesis in fish and the effects of growth on this process are poorly understood. In this study interactions between the growth and reproductive systems were examined by monitoring changes in various components of the FSH-ovary axis, plasma insulin-like growth factor 1 (Igf1), and ovarian gene expression in relation to body and previtellogenic oocyte growth in coho salmon. Samples were collected from females during two hypothesized critical periods when growth influences maturation in this species. Body growth during the fall-spring months was strongly related to the degree of oocyte development, with larger fish possessing more advanced oocytes than smaller, slower growing fish. The accumulation of cortical alveoli in the oocytes was associated with increases in plasma and pituitary FSH, plasma estradiol-17beta, and ovarian steroidogenic acute regulatory protein (star) gene expression, whereas ovarian transcripts for growth hormone receptor and somatolactin receptor decreased. As oocytes accumulated lipid droplets, a general increase occurred in plasma Igf1 and components of the FSH-ovary axis, including plasma FSH, estradiol-17beta, and ovarian mRNAs for gonadotropin receptors, star, igf1, and igf2. A consistent positive relationship between plasma Igf1, estradiol-17beta, and pituitary FSH during growth in the spring suggests that these factors are important links in the mechanism by which body growth influences the rate of oocyte development.

Role of the C-terminal actin binding domain in BCR/ABL-mediated survival and drug resistance

Philadelphia chromosome-positive, chronic myeloid leukaemia (CML) stem and progenitor cells have a survival and growth advantage compared with their normal counterparts. The mechanisms through which the BCR/ABL protein tyrosine kinase (PTK) induces these effects and the important domains within this protein are not fully defined. The F- and G-actin binding region of the BCR/ABL C-terminus may be important in BCR/ABL-mediated events, and we have investigated this by expressing a C-terminus deletion mutant of the temperature-sensitive BCR/ABL PTK, in a haemopoietic progenitor cell line, which models the chronic phase of CML. The truncated BCR/ABL PTK displayed similar levels of PTK activity when compared with wild type and activation of second messenger formation (in the form of sn-1,2-diacylglycerol) remains intact. On fibronectin substrata, localisation of the protein to the periphery of the cell was, however, dependent on the C-terminus of BCR/ABL PTK. Deletion of the C-terminus reversed both BCR/ABL-mediated apoptotic suppression and drug resistance although the progenitor cells did retain a proliferative advantage at low concentrations of growth factor. These results demonstrated that the C-terminal actin-binding domain of BCR/ABL is important for some of BCR/ABL PTK-mediated leukaemogenic effects.

The presence of a transsulfuration pathway in the lens: a new oxidative stress defense system

The finding that a lens under oxidative stress accumulated free and protein-bound cysteine (protein-S-S-cysteine) in the fiber cells prompted us to examine if there is an alternative source for cysteine pools besides the active cysteine transport system in the lens, namely, the transsulfuration pathway of homocysteine-cystathionine-cysteine, which utilises methionine through transmethylation. We examined the presence of the gene for cystathionine-beta-synthase (CBS), the rate limiting enzyme that converts homocysteine to cystathionine in the transsulfuration pathway, in human lens epithelial (HLE) B3 cells using PCR with primers designed based on the sequence of human liver CBS (Forward 5'-CCA CAC TGC CCC GGC AAA AT-3'; Reverse 5'-CTG GCA ATG CCC GTG ATG GT-3'). The purified DNA fragment (586 bp) from PCR analysis was sequenced and confirmed the homology with CBS gene from other human tissues. The CBS protein band (67 kDa) was present in the HLE cells, which reacted positively with the human liver anti-CBS antibody. The enzyme protein was detected in the pig and human lenses with the highest intensity in the epithelial layer, lower but equal quantities of CBS was present in the cortical and nuclear regions. Human nuclear CBS increased while epithelial CBS decreased with aging. Oxidative stress transiently upregulated the gene expression of CBS both in HLE cells (0.1 mMH2O2) and in pig lens cultured in TC 199 medium (0.5 mMH2O2). The catalytic activity for CBS, which was assayed by measuring the production of C14-cystathionine from C14-serine in the presence of homocysteine, S-adenosyl-methionine and pyridoxal phosphate, was detectable in the HLE cells and transiently activated with H2O2. Free cystathionine accumulated when HLE B3 cells were treated with propargylglycine (PGG), an inhibitor of cystathionase, the downstream enzyme that converts cystathionine to cysteine. More cystathionine accumulation occurred when the cells were simultaneously exposed to PGG and 0.1 mMH2O2. We have shown that oxidative stress of H2O2 could increase the flux of this transsulfuration pathway by committing more homocysteine to cysteine and glutathione production as H2O2 (0.1 mM) inhibited the remethylation enzyme of methionine synthase while concurrently activating the CBS enzyme. This is the first evidence that a transsulfuration pathway is present in the lens, and that it can be upregulated under oxidative stress to provide additional redox potential for the cells.

The diagnosis and surgical management of major salivary gland pathology

BACKGROUND

Major salivary gland pathology is an uncommon but important finding which may initially present to general dental and medical practitioners. The consequences of misdiagnosis are important, as acute obstruction and neoplasia are the main pathological lesions diagnosed. The purpose of this study was to analyze a consecutive series of major gland pathologies treated surgically to determine diagnostic and treatment problems.

METHODS

A retrospective analysis of all cases of the major salivary glands treated on an inpatient surgical basis over a five-year period by the Oral and Maxillofacial Surgery Unit of the Royal Adelaide Hospital was performed. Particular emphasis was placed on the referring diagnosis as compared to the final diagnosis.

RESULTS

Fifty-four patients had surgical management of 62 major salivary glands over the five-year period. By gland, 18 (33.3 per cent) were parotid, 35 (51.1 per cent) submandibular and nine (16.6 per cent) were sublingual. Fifty-one (82 per cent) of all lesions were inflammatory and 11 (18 per cent) neoplastic. The most common presentations were swelling (72 per cent) and pain (33 per cent). Most patients were referred by general dentists (37 per cent), followed by general medical practitioners (32 per cent) and specialists (28 per cent). The referring diagnosis was correct for only 45 per cent of the dentists but 76 per cent for the general medical practitioners and 87 per cent for the specialists. Only two of the 11 gland neoplasms were correctly identified as neoplasms, both by specialists. The morbidity of the surgical treatment was low.

CONCLUSION

The general dental practitioner is often the first health professional with the opportunity to assess salivary gland pathology, and therefore needs to be aware of the presenting signs and symptoms of major salivary gland lesions.

HIV Lipodystrophy Case Definition using Artificial Neural Network Modelling

Objective

A case definition of HIV lipodystrophy has recently been developed from a combination of clinical, metabolic and imaging/body composition variables using logistic regression methods. We aimed to evaluate whether artificial neural networks could improve the diagnostic accuracy.

Methods

The database of the case-control Lipodystrophy Case Definition Study was split into 504 subjects (265 with and 239 without lipodystrophy) used for training and 284 independent subjects (152 with and 132 without lipodystrophy) used for validation. Back-propagation neural networks with one or two middle layers were trained and validated. Results were compared against logistic regression models using the same information.

Results

Neural networks using clinical variables only (41 items) achieved consistently superior performance than logistic regression in terms of specificity, overall accuracy and area under the ROC curve. Their average sensitivity and specificity were 72.4 and 71.2%, as compared with 73.0 and 62.9% for logistic regression, respectively (area under the ROC curve, 0.784 vs 0.748). The discriminating performance of the neural networks was largely unaffected when built excluding 13 parameters that patients may not have readily available. The average sensitivity and specificity of the neural networks remained the same when metabolic variables were also considered (total 60 items) without a clear advantage against logistic regression (overall accuracy 71.8%). The performance of networks considering also body composition variables was similar to that of logistic regression (overall accuracy 78.5% for both).

Conclusions

Neural networks may offer a means to improve the discriminating performance for HIV lipodystrophy, when only clinical data are available and a rapid approximate diagnostic decision is needed. In this context, information on metabolic parameters is apparently not helpful in improving the diagnosis of HIV lipodystrophy, unless imaging and body composition studies are also obtained.

[Influence of chemotherapeutants and cytokines on growth and transgene expression of bone marrow cells from MT/p210(bcr-abl) transgenic mice]

The bone marrow cells of CML(chronic myelogenous leukemia) transgenic mice carrying metallothionein(MT) promoter/enhancer, bcr-abl(p210) cDNA and SV40 splicing/poly(A) signal sequences were cultured in liquid and soft agar with hydroxyurea (Hu), 5-fluorouracil(5-Fu), mouse stem cell factor (mSCF) and mouse interleukin-3(mIL-3) independently or combinatively. The cell or colony counting and transgene RT-PCR analysis showed that the proliferation, colony formation and transgene expression of the bone marrow cells were advanced in the combinative culture of mSCF with mIL-3, but they were significantly inhibited in the culture without any growth factors, or with mSCF, mIL-3 and Hu or 5-Fu. These findings suggest that the combinative utilization of chemotherapeutants and cytokines is a potentially effective strategy of the clinical treatment for CML.

The specific enhancement of interferon alpha induced growth inhibition by BCR/ABL only occurs in multipotent cells

INTRODUCTION

The causative oncogene in CML is the BCR/ABL protein tyrosine kinase. This stem cell disease is often treated with interferon alpha (IFN-alpha) which can initiate haematological and cytological remission which is associated with increased survival. There is however no clear indication of why CML cells are more responsive to IFN-alpha.

MATERIALS AND METHODS

To establish if BCR/ABL increases the sensitivity of multipotent cells to IFN-alpha a temperature sensitive mutant of BCR/ABL was expressed in the multipotent haemopoietic stem cell line FDCP-Mix. The effect of IFN-alpha in terms of proliferation, induction of apoptosis, changes in cell cycle inhibitor proteins, and differentiation was assessed by [3H]thymidine incorporation, Annexin V and Western blot analysis.

RESULTS

When the BCR/ABL tyrosine kinase was activated, the IFN-alpha-induced inhibition on the growth rate of the FDCP-Mix cell population was more marked than in control populations. The BCR/ABL-mediated effect was due to decreased rates of DNA synthesis. There was no IFN-alpha-mediated induction of apoptosis. This enhanced BCR/ABL mediated growth inhibition occurred over a range of growth factor concentrations and was independent of changes in p21(Cip1) and p27(Kip) levels. When FDCP-Mix cells were induced to differentiate into mature macrophages and neutrophils in the presence of IFN-alpha, there was increased sensitivity to IFN-alpha that was independent of BCR/ABL activity.

CONCLUSION

BCR/ABL PTK expression in this primitive multipotent haematopoietic cell line results in an enhanced response to IFN-alpha. In contrast, the more mature myeloid progenitor cells are equally responsive to this growth inhibitor. This data may explain some of the clinical effects of IFN-alpha.