Biomedical subjects

T Patel

Publications and source records attributed to T Patel.

At least 19 recordsLinked to original sources

PubMed2005

The clinical importance of axillary lymphadenopathy detected on screening mammography: revisited.

AIM: The aim of this study was to re-evaluate our protocol for the management of isolated axillary lymphadenopathy (ALP) on mammographic screening. METHODS: In a retrospective review of 200,716 women screened at the South West London Breast Screening Service (SWLBSS) over 7 years, 72 women with ALP with an otherwise normal mammogram were identified. Thirteen patients were not recalled, nine of who had a known underlying diagnosis and the remainder had longstanding unchanged mammograms. Fifty-nine patients were recalled for further clinical assessment and investigations, including ultrasound, further mammographic views, fine-needle aspiration cytology (FNAC), blood tests and a chest radiograph. Those with a definite diagnosis were referred for appropriate management and those with benign reactive cytology on FNAC reviewed at 6 weeks with subsequent referral for excision of persisting abnormal nodes. RESULTS: The ultimate diagnosis was benign in 45 cases: 26 benign reactive changes, 11 arthritides, five with dermatological and viral conditions and three with tuberculosis. Malignancy was diagnosed in 13 cases: four with metastatic breast carcinoma and nine with lymphoma/leukaemia. The total number of newly diagnosed malignancies was 20% of women recalled. Another 5% of patients had active tuberculosis. Of the 22 patients with benign reactive cytology, one had significant pathology on excision biopsy: tuberculosis. Over 95% of the results from excision biopsy in these patients did not alter management. CONCLUSION: In the majority of patients, the FNAC results were representative of the final excision pathology. The present study suggests that excision biopsy could be omitted for those patients whose FNAC and culture are negative.

Aged↗

PubMed2005

The tumour necrosis factor-alpha inhibitor adalimumab rapidly reverses the decrease in epidermal Langerhans cell density in psoriatic plaques.

BACKGROUND: The pathophysiology of psoriasis is poorly understood, and the mechanism of action of biological agents interfering with tumour necrosis factor (TNF)-alpha that improve psoriatic plaques is completely unknown. OBJECTIVES: To begin to unravel the mechanism of action, cellular changes occurring in plaques following administration of adalimumab, a humanized monoclonal antibody against TNF-alpha, were investigated. METHODS: Thirteen different patients underwent sequential biopsies as part of a clinical trial. Each biopsy was immunostained and evaluated to calculate the relative density of epidermal Langerhans cells (LCs) before and after treatment (days 2, 7, 28, 84). To explore the basis for reduced epidermal LC densities in plaques, a SCID-Hu animal model was utilized. Acute psoriatic lesions were created within 2 weeks by injection of superantigen-activated CD4+ T cells into engrafted symptomless skin. RESULTS: Compared with symptomless skin, untreated plaques had a significantly reduced density of epidermal LCs. There was a rapid increase in density of epidermal LCs in plaques following treatment with adalimumab beginning as early as day 7. The paucity of epidermal LCs in plaques was contrasted to the prominent density of LCs in other skin disorders with chronic inflammation and alterations in keratinization, including lichen planus and inflamed seborrhoeic keratosis. Rapid creation of plaques using the SCID-Hu model was accompanied by loss of epidermal LCs, indicating that diminished LC density occurs at an early stage of lesion formation. CONCLUSIONS: These data shed light on a new immunopathological perspective highlighting a rapid loss of epidermal LCs in acute psoriatic lesions, with sustained decreased density of LCs in chronic plaques. Furthermore, an unexpected insight into the mechanism of action was uncovered for adalimumab, in which rapid restoration of epidermal LC density was observed.

Adalimumab↗

PubMed2005

Improving medication management for patients: the effect of a pharmacist on post-admission ward rounds.

PROBLEM: Medication management in the NHS has been highlighted by the UK Department of Health as an area for improvement. Pharmacist participation on post-take (post-admission) ward rounds was shown to reduce medication errors and reduced prescribing costs in the USA and in UK teaching hospitals, which can contribute to improved medication management. We sought to demonstrate the problem in our hospital by collecting data on prescribing practice from three consecutive general medical post-take ward rounds. SETTING: Northwick Park Hospital, a district general hospital in north-west London, which provides acute medical services to a population of 300,000. STRATEGY FOR CHANGE: A pharmacist was invited to become a member of the post-take ward round team that reviewed medical patients admitted within the preceding 24 hours. Patients also continued to receive care from a ward based pharmacist. Patient notes were analysed for cost of drugs on admission and discharge, discrepancies between admission drug history and pharmacist history, number of admission drugs stopped before discharge, and pharmacist recommendations. Pharmacist recommendations and actions were classified using a National Patient Safety Agency risk matrix. EFFECTS OF CHANGE: Discrepancies between the admission and the pharmacist derived drug history were noted in 26 of 50 in the pre-intervention group and 52 of 53 in the intervention group. The annual drug cost per patient following discharge increased by pounds 181 in the pre-intervention group and by pounds 122 in the intervention group. Five pre-admission drugs were stopped in three pre-intervention patients saving pounds 276 per annum, while the 42 drugs stopped in 19 intervention patients saved pounds 4699 per annum. No ward based pharmacist recommendations were recorded in the pre-intervention group. Recommendations regarding drug choice, dose, and need for drug treatment were most common; 58 minor, 48 moderate and four major risks to patients were potentially avoided. LESSONS LEARNT: The presence of a pharmacist on a post-take ward round improved the accuracy of drug history documentation, reduced prescribing costs, and decreased the potential risk to patients in our hospital. As a result of this work a full time pharmacist has now been funded to attend daily post-take ward rounds on a permanent basis.

Drug Costs↗

PubMed2002

Structure-affinity relationships in the gp41 ELDKWA epitope for the HIV-1 neutralizing monoclonal antibody 2F5: effects of side-chain and backbone modifications and conformational constraints.

The human monoclonal antibody, mAb 2F5, has broad HIV-1 neutralizing activity and binds a conserved linear epitope within the envelope glycoprotein gp41 having a core recognition sequence ELDKWA. In this study, the structural requirements of this epitope for high-affinity binding to mAb 2F5 were explored using peptide synthesis and competitive enzyme-linked immunosorbant assay (ELISA). Expansion of the minimal epitope to an end-capped, linear nonapeptide, Ac-LELDKWASL-amide, was sufficient to attain maximal affinity within the set of native gp41-sequence peptides assayed. Scanning single-residue alanine and d-residue substitutions then confirmed the essential recognition requirements of 2F5 for the central DKW sequence, and also established the importance of the terminal leucine residues in determining high-affinity binding of the linear nonapeptide. Further studies of side-chain and backbone-modified analogs revealed a high degree of structural specificity for the DK sequence in particular, and delineated the steric requirements of the Leu(3) and Trp(6) residues. The nine-residue 2F5 epitope, flanked by pairs of serine residues, retained a high affinity for 2F5 when it was conformationally constrained as a 15-residue, disulfide-bridged loop. However, analogs with smaller or larger loop sizes resulted in lower 2F5 affinities. The conformational effects of the gp41 C-peptide helix immediately adjacent to the N-terminal end of the ELDKWA epitope were examined through the synthesis of helix-initiated analogs. Circular dichroism (CD) studies indicated that the alpha-helical conformation was propagated efficiently into the LELDKWASL epitope, but without any significant effect on its affinity for 2F5. This study should guide the design of a second generation of conformationally constrained ELDKWA analogs that might elicit an immune response that mimics the HIV-neutralizing actions of 2F5.

Amino Acid Sequence↗

PubMed2001

Interpretation of the excess adsorption isotherms of organic eluent components on the surface of reversed-phase adsorbents. Effect on the analyte retention.

The excess adsorption isotherms of acetonitrile, methanol and tetrahydrofuran from water on reversed-phase packings were studied, using 10 different columns packed with C1-C6, C8, C10, C12, and C18 monomeric phases, bonded on the same type of silica. The interpretation of isotherms on the basis of the theory of excess adsorption shows significant accumulation of the organic eluent component on the adsorbent surface on the top of "collapsed" bonded layer. The accumulated amount was shown to be practically independent of the length of alkyl chains bonded to the silica surface. A model that describes analyte retention on a reversed-phase column from a binary mobile phase is developed. The retention mechanism involves a combination of analyte distribution between the eluent and organic adsorbed layer, followed by analyte adsorption on the surface of the bonded phase. A general retention equation for the model is derived and methods for independent measurements of the involved parameters are suggested. The theory was tested by direct measurement of analyte retention from the eluents of varied composition and comparison of the values obtained with those theoretically calculated values. Experimental and theoretically calculated values are in good agreement.

Acetonitriles↗

PubMed2001

Proteomic comparison of human and great ape blood plasma reveals conserved glycosylation and differences in thyroid hormone metabolism.

Most blood plasma proteins are glycosylated. These glycoproteins typically carry sialic acid-bearing sugar chains, which can modify the observed molecular weights and isoelectric points of those proteins during electrophoretic analyses. To explore changes in protein expression and glycosylation that occurred during great ape and human evolution, we subjected multiple blood plasma samples from all these species to high-resolution proteomic analysis. We found very few species-specific differences, indicating a remarkable degree of conservation of plasma protein expression and glycosylation during approximately 12 million years of evolution. A few lineage-specific differences in protein migration were noted among the great apes. The only obvious differences between humans and all great apes were an apparent decrease in transthyretin (prealbumin) and a change in haptoglobin isoforms (the latter was predictable from prior genetic studies). Quantitative studies of transthyretin in samples of blood plasma (synthesized primarily by the liver) and of cerebrospinal fluid (synthesized locally by the choroid plexus of the brain) confirmed approximately 2-fold higher levels in chimpanzees compared to humans. Since transthyretin binds thyroid hormones, we next compared plasma thyroid hormone parameters between humans and chimpanzees. The results indicate significant differences in the status of thyroid hormone metabolism, which represent the first known endocrine difference between these species. Notably, thyroid hormones are known to play major roles in the development, differentiation, and metabolism of many organs and tissues, including the brain and the cranium. Also, transthyretin is known to be the major carrier of thyroid hormone in the cerebrospinal fluid, likely regulating delivery of this hormone to the brain. A potential secondary difference in retinoid (vitamin A) metabolism is also noted. The implications of these findings for explaining unique features of human evolution are discussed.

Animals↗

PubMed2001

Successful stenting of a complex inferior vena cava stenosis using a modified sharp recanulization technique.

We describe a case of a 30-year-old male who presented with features of noncirrhotic portal hypertension, who was diagnosed to have inferior vena cava (IVC) obstruction. IVC angiogram and ultrasound study revealed a long-segment (36 mm long), chronic total thrombotic occlusion that was dilated and stented with a satisfactory end result. The unique feature of this case is a modified sharp recanulization technique involving the use of Brokenborough (septal puncture) needle and Mullin dilator to create a track in such a long, chronic total occlusion under simultaneous ultrasound and fluoroscopic guidance.

Adult↗

PubMed2001

Second-line chemotherapy for non-small-cell lung cancer with monthly docetaxel and weekly gemcitabine: a phase II trial.

BACKGROUND: Docetaxel and gemcitabine are active against chemotherapy-pretreated non-small-cell lung cancer (NSCLC). The purpose of this phase II study was to evaluate the efficacy and safety of monthly docetaxel combined with weekly gemcitabine in NSCLC patients failing one prior regimen. PATIENTS AND METHODS: Forty patients were enrolled. Prior chemotherapy was a platinum-based combination in 36 patients, using vinorelbine in 26 patients and etoposide in 10 patients. The other four patients had prior single agents. Tumors were refractory or resistant to front-line therapy in 80% of patients. Treatment was gemcitabine 800 mg/m2 days 1, 8, 15 and docetaxel 100 mg/m2 day 1, with cycles repeated every four weeks. RESULTS: Thirteen patients responded (32.5%; 95% confidence interval (CI): 19%-49%), including one complete and 12 partial responses. Responses were observed at all metastatic sites, with similar response frequencies in platinum-sensitive and platinum-resistant/refractory tumors. The median time to progression for responders was nine months, with two responses lasting longer than a year. Median survival was 8.1 months. Hematologic toxicities included grade 4 neutropenia in 23 patients, with 4 episodes of febrile neutropenia, grade 3-4 thrombocytopenia in 9 patients, and anemia requiring red cell transfusions in 9 patients. With the exception of asthenia, severe non-hematologic toxicities were infrequent. CONCLUSIONS: Monthly docetaxel, combined with weekly gemcitabine, is an active and safe second-line therapy for NSCLC patients.

Adult↗

PubMed2001

Monthly docetaxel and weekly gemcitabine in metastatic breast cancer: a phase II trial.

BACKGROUND: Docetaxel and gemcitabine are active against breast cancer. The purpose of this phase II study was to evaluate the efficacy and safety of monthly docetaxel combined with weekly gemcitabine in patients with chemotherapy-pretreated metastatic breast cancer. PATIENTS AND METHODS: Thirty-nine patients were enrolled, of whom thirty had received prior chemotherapy in the adjuvant setting, seven for metastatic disease, and two for both, including prior anthracycline in 33 patients. Treatment was gemcitabine 800 mg/m2 days 1, 8, 15 and docetaxel 100 mg/M2 on day 1, with cycles repeated every four weeks. RESULTS: Response rate was 79% (95% confidence interval (CI): 63%-91%), with 2 complete and 29 partial responses. Twenty-five of the responders remained progression-free for more than six months. Median survival was 24.5 months. Delivered dose intensity of gemcitabine was lower than expected (63% of planned). The predominant hematologic toxicity was grade 4 neutropenia in 36 patients, complicated by fever in three patients. With the exception of asthenia, severe non-hematological toxicities were infrequent. CONCLUSIONS: Monthly docetaxel, combined with weekly gemcitabine, has significant but manageable hematologic toxicity. Despite frequent dose adjustments, this doublet is very active in metastatic breast cancer, producing a high proportion of durable responses associated with favorable survival.

Adult↗

PubMed2001

Involvement of p38 mitogen-activated protein kinase signaling in transformed growth of a cholangiocarcinoma cell line.

Although mitogen-activated protein kinase (MAPK) pathways play a key role in cell growth, their role in mediating the altered growth phenotype of transformed cells remains unclear. The p44/p42 MAPK signaling cascades are activated by mitogenic stimulation of human cholangiocytes. In contrast, the p38 MAPK pathway is activated by mitogen stimulation of malignant, but not nonmalignant cholangiocytes. Thus, our aims were to determine the role of p38 MAPK signaling in mediating the growth phenotype of transformed cholangiocytes. KMCH-1 malignant human cholangiocytes required the presence of serum for proliferation, but were able to grow in reduced serum conditions. Inhibition of p38 MAPK decreased serum-dependent proliferation of KMCH-1 cells. Furthermore, inhibition of p38 MAPK, but not of p44/p42 MAPK, reduced anchorage-independent growth of KMCH-1 cells. Although both p38 and p44/p42 MAPK are activated in response to mitogens, they have divergent effects on anchorage-independent growth. Inhibition of p38 MAPK, but not of p44/p42 MAPK signaling, decreased cell cycle progression and increased expression of the cyclin-dependent kinase inhibitor p21(WAF1/CIPl). However, expression of p27(KIP1) or p16(INK4A) was not altered by either pathway. Thus, mitogen activation of p38 MAPK decreases expression of p21(WAF1/CIP1) and mediates growth independent of anchorage signals, whereas mitogen activation of p44/p42 MAPK mediates an anchorage signal-dependent growth pathway. These data provide a link between aberrant stress-activated cell signaling and the altered growth phenotype of transformed cells that may be important for the development of therapies to limit transformed cell growth.

Bile Duct Neoplasms↗

PubMed2001

Increasing incidence and mortality of primary intrahepatic cholangiocarcinoma in the United States.

Clinical observations suggest a recent increase in intrahepatic biliary tract malignancies. Thus, our aim was to determine recent trends in the epidemiology of intrahepatic cholangiocarcinoma in the United States. Reported data from the Surveillance, Epidemiology, and End Results (SEER) program and the United States Vital Statistics databases were analyzed to determine the incidence, mortality, and survival rates of primary intrahepatic cholangiocarcinoma. Between 1973 and 1997, the incidence and mortality rates from intrahepatic cholangiocarcinoma markedly increased, with an estimated annual percent change (EAPC) of 9.11% (95% CI, 7.46 to 10.78) and 9.44% (95%, CI 8.46 to 10.41), respectively. The age-adjusted mortality rate per 100,000 persons for whites increased from 0.14 for the period 1975-1979 to 0.65 for the period 1993-1997, and that for blacks increased from 0.15 to 0.58 over the same period. The increase in mortality was similar across all age groups above age 45. The relative 1- and 2-year survival rates following diagnosis from 1989 to 1996 were 24.5% and 12.8%, respectively. In conclusion, there has been a marked increase in the incidence and mortality from intrahepatic cholangiocarcinoma in the United States in recent years. This tumor continues to be associated with a poor prognosis.

Black or African American↗

PubMed2000

Broken guidewire fragment: a simplified retrieval technique.

We report a technique for retrieval of a broken angioplasty wire fragment from the coronary system using a more simplified technique that does not involve the use of a snare or any other retrieval tool. With the use of an additional angioplasty wire and a balloon catheter, we could safely remove the broken wire fragment from the coronary system and circulation in a very short time.

Angioplasty, Balloon, Coronary↗

PubMed2000

Apoptosis in hepatic pathophysiology.

Apoptosis is a fundamental biologic process that is important in many physiologic and pathophysiologic processes in the liver. Although dysregulation of apoptosis may contribute to a wide range of diseases, the role of this process in liver disease and pathophysiology has only recently begun to be recognized and remains to be fully defined. Several important questions remain unanswered: How does excessive apoptosis in response to injury contribute to inflammation and fibrogenesis in the liver? How does control of apoptosis contribute to the regulation of hepatic structure following injury? What is the role of death receptors in hepatic disease? Can an understanding of apoptosis be helpful in therapeutic modulation of specific liver diseases or liver cancer? The identification of target molecules involved in apoptosis raises the prospect of pharmacologic modulation that may result in better treatment options for patients with liver diseases. Inhibition of apoptosis is likely to be useful in treating fulminant hepatic failure or in organ preservation before transplantation. In these situations, treatment is for a limited period, and the potential hazards of nonselective long-term inhibition of apoptosis are minimized. Safe and organ-specific inhibitors of apoptosis would be required for prolonged treatment of chronic liver diseases. For treatment of liver tumors, the goal is to induce apoptosis selectively in cancer cells. Drugs that decrease the apoptotic threshold by modulating the intracellular regulatory mechanisms and drugs that enhance the susceptibility of cancer cells to undergo immune-mediated apoptosis will be useful in the treatment of liver cancers. The rapid advances in the understanding of the intracellular mechanisms and the regulation of apoptosis will ultimately result in a better understanding of the role of apoptosis in the pathophysiology of liver diseases and may allow therapeutic modulation of this process.

Apoptosis↗

PubMed2000

Silymarin in the treatment of patients with primary biliary cirrhosis with a suboptimal response to ursodeoxycholic acid.

Ursodeoxycholic acid (UDCA) is a safe and effective medical therapy for most patients with primary biliary cirrhosis (PBC), but some patients show an incomplete response. Silymarin is a potent antioxidant with immunomodulatory and antifibrotic properties. The aim of this study was to evaluate the safety and assess the efficacy of silymarin in patients with PBC who had shown a suboptimal response to UDCA. Twenty-seven patients with PBC who had been on UDCA (13-15 mg/kg/day) therapy for 7 to 221 months and had shown a persistent elevation of alkaline phosphatase activity at least 2 times the upper limit of normal for more than 6 months were enrolled. Oral silymarin, 140 mg 3 times daily was given for 1 year, and patients continued on the same dosage of UDCA. No significant changes in serum alkaline phosphatase activity (897 +/- 84 vs. 876 +/- 95, P =.5), total bilirubin (0.9 +/- 0.1 vs. 1 +/- 0.1, P =.07), aspartate transaminase (AST) (58 +/- 5 vs. 56 +/- 6, P =.4), albumin (4.0 +/-.06 vs. 4.1 +/-.06, P =.4), or Mayo risk score (3.82 +/- 0.2 vs. 3.88 +/- 0.2, P =.4) were noted after 1 year of treatment with combination therapy. Transitory gastrointestinal adverse events occurred in 2 patients. In conclusion, although silymarin was well tolerated, this medication did not provide benefit to patients with PBC responding suboptimally to UDCA. The results of this pilot study would seem to discourage further controlled trials of silymarin in patients with PBC.

Administration, Oral↗

PubMed2000

Efficacy and safety of ten day moxifloxacin 400 mg once daily in the treatment of patients with community-acquired pneumonia. Community Acquired Pneumonia Study Group.

Community-acquired pneumonia (CAP) remains a common and serious illness with approximately 2-4 million cases reported annually. Management of CAP is therapeutically challenging due to the increasing prevalence of penicillin- and macrolide-resistant pneumococci and beta-lactamase producing Haemophilus influenzae, as well as the increased recognition of 'atypical' pathogens, such as Chlamydia pneumoniae and Mycoplasma pneumoniae, and the frequent need for empiric therapy. We aimed to evaluate the safety and efficacy of moxifloxacin in the treatment of patients with CAP. To do this we carried out a prospective, uncontrolled, non-blind, Phase III clinical trial, in 27 U.S. centers. Patients included in the study were over 18 years of age with signs and symptoms of CAP confirmed by evidence of a new or progressive infiltrate on chest radiograph. The intervention used was moxifloxacin 400 mg PO once daily for 10 days. Sputum samples were collected pretherapy for Gram stain and culture for typical organisms. Culture and serological testing for Chlamydia pneumoniae and Mycoplasma pneumoniae was also performed. Susceptibility to moxifloxacin was determined by disk diffusion and MIC. Clinical and bacteriological responses were determined at the end of therapy (0-6 days post-therapy), follow-up (14-35 days post-therapy) and overall (end of therapy plus follow-up). Analyses were performed on both valid for efficacy and intent-to-treat populations. The primary efficacy variable was overall clinical resolution. Of 254 patients enrolled in the Study, 196 patients were included in the efficacy analyses. The majority of patients were male (58%) and Caucasian (85%) with a mean age of 49 years (range: 18 to 85 years). Only 3% of patients were hospitalized pretherapy. The most common pretherapy organisms identified, by culture or serology, in the valid for efficacy population (i.e. 147 organisms among 116 patients), were: Chlamydia pneumoniae (n=63; 54%), Mycoplasma pneumoniae (n=29; 25%), Streptococcus pneumoniae (n=14; 12%) and Haemophilus influenzae (n=13; 10%). End of therapy, follow-up and overall clinical resolution rates for the valid for efficacy population were 94%, 93% and 93%, respectively. The 95% CI for the overall clinical resolution rate was 88.1%, 95.9%. The overall bacteriological response for patients diagnosed by culture or serological criteria, was 91% (95% CI=84%, 96%). For patients who only met serological criteria for infection, the overall bacteriological response was 94% (60/64). Bacterial response rates for the four most commonly isolated pathogens were: 89% (56/63) for C. pneumoniae, 93% (27/29) for M. pneumoniae, 93% (13/14) for S. pneumoniae and 85% (11/13) for H. influenzae. Drug-related adverse events were reported in 33% (85/254) of moxifloxacin-treated patients. Nausea (9%), diarrhea (6%) and dizziness (4%) were the most commonly reported adverse events. Atypical organisms were isolated in high frequency among patients with CAP. Moxifloxacin 400 mg once daily for 10 days was effective and well-tolerated in the treatment of these adult patients with CAP. Moxifloxacin offers an effective treatment alternative for CAP due to both typical and atypical bacterial pathogens.

Adolescent↗

PubMed2000

Importance of membrane fusion mediated by human immunodeficiency virus envelope glycoproteins for lysis of primary CD4-positive T cells.

In established T-cell lines, the membrane-fusing capacity of the human immunodeficiency virus type 1 (HIV-1) envelope glycoproteins mediates cytopathic effects, both syncytium formation and single-cell lysis. Furthermore, changes in the HIV-1 envelope glycoproteins are responsible for the increased CD4(+) T-cell-depleting ability observed in infected monkeys upon in vivo passage of simian-human immunodeficiency virus (SHIV) chimeras. In this study, a panel of SHIV envelope glycoproteins and their mutant counterparts defective in membrane-fusing capacity were expressed in primary human CD4(+) T cells. Compared with controls, all of the functional HIV-1 envelope glycoproteins induced cell death in primary CD4(+) T-cell cultures, whereas the membrane fusion-defective mutants did not. Death occurred almost exclusively in envelope glycoprotein-expressing cells and not in bystander cells. Under standard culture conditions, most dying cells underwent lysis as single cells. When the cells were cultured at high density to promote syncytium formation, the envelope glycoproteins of the passaged, pathogenic SHIVs induced more syncytia than those of the respective parental SHIV. These results demonstrate that the HIV-1 envelope glycoproteins induce the death of primary CD4(+) T lymphocytes by membrane fusion-dependent processes.

CD4-Positive T-Lymphocytes↗

PubMed2000

A cost-benefit analysis of the effect of shipboard telemedicine in a selected oceanic region.

Data from a selected oceanic region, the UK search and rescue region, were used to establish the average annual of ship diversions and emergency service call-outs arising from urgent medical problems of passengers or crew. During the period 1997-8 there were 228 medical evacuations. An attempt was made to estimate the extent to which some or all of the diversions and call-outs could have been averted if telemedical facilities had been available on-board the ships. The analysis showed that telemedicine would be an expensive alternative to existing evacuation methods, but did not allow for the fact that helicopter and lifeboat evacuations cannot be carried out in bad weather or at distances over 200 nautical miles (370 km) from land. Taking into consideration the cost of ship diversions in such circumstances produces completely different results. Telemedicine could clearly provide substantial cost-savings for the shipping industry, and a separate analysis focused on the shipowner alone would make an overwhelming economic argument for investment in a telemedicine service simply on the strength of diversion avoidance.

Cost-Benefit Analysis↗

PubMed1999

Stabilizing potential of anterior cervical plates in multilevel corpectomies.

STUDY DESIGN: An in vitro investigation of three-dimensional kinematics of cervical spine models of one- and three-level corpectomy with anterior plate fixation. OBJECTIVES: To evaluate the capability of an anterior plate to stabilize the reconstructed cervical spine under simulated physiologic motions, and to study the effects of fatigue loading. SUMMARY OF BACKGROUND DATA: Clinical studies have found high failure rates of multilevel anterior cervical plate fusions, indicating suboptimal stabilization. However, no biomechanical studies have been done to investigate the stabilizing capabilities of long-plate instrumentations in corpectomy models. METHODS: Seven fresh human cadaveric cervical spine specimens (C2-T1) were used. Flexibility tests consisted of flexion, extension, and bilateral torsion, and lateral bending, each with a pure moment of 0.25, 0.5, 0.75, and 1.0 Nm. Stabilizing potential indices [(MotionIntact-MotionInstrumented)/MotionIntact] for ranges of motion and neutral zones obtained from the flexibility tests, were measured when the specimen was intact and after one-level (C5) and three-level (C4, C5, and C6) corpectomies and anterior plate stabilizations). The stabilizing potential indices were re-measured after a 1000-cycle fatigue loading (1 Nm flexion and extension moments at C5 vertebra at 0.14 Hz). RESULTS: The differences in stabilizing potential indices of range of motion and neutral zone between one-level and three-level plates were not significant before fatigue. However, after fatigue, the stabilizing potential indices significantly decreased (P < 0.05) for the three-level model, but not for the one-level plate model. CONCLUSIONS: The capability of an anterior cervical plate to stabilize the spine after three-level corpectomy was significantly reduced with fatigue loading.

Adolescent↗