The nature of organic records in impact excavated rocks on Mars

Impact ejected rocks are targets for life detection missions to Mars. The Martian subsurface is more favourable to organic preservation than the surface owing to an attenuation of radiation and physical separation from oxidising materials with increasing depth. Impact events bring materials to the surface where they may be accessed without complicated drilling procedures. On Earth, different assemblages of organic matter types are derived from varying depositional environments. Here we assess whether these different types of organic materials can survive impact events without corruption. We subjected four terrestrial organic matter types to elevated pressures and temperatures in piston-cylinder experiments followed by chemical characterisation using whole-rock pyrolysis-gas chromatography-mass spectrometry. Our data reveal that long chain hydrocarbon-dominated organic matter (types I and II; mainly microbial or algal) are unresistant to pressure whereas aromatic hydrocarbon-dominated organic matter types (types III and IV; mainly land plant, metamorphosed or degraded, displaying some superficial chemical similarities to abiotic meteoritic organic matter) are relatively resistant. This suggests that the impact excavated record of potential biology on Mars will be unavoidably biased, with microbial organic matter underrepresented while metamorphosed, degraded or abiotic meteoritic organic matter types will be selectively preserved.

Medication discontinuation with depot and oral antipsychotics in outpatients with schizophrenia: comparison of matched cohorts from a 12-month observational study

AIMS

This study compared all-cause medication discontinuation (any switch, augmentation or medication discontinuation) in matched cohorts of patients with schizophrenia who were initiated on depot or oral antipsychotics. Other objectives included between-group comparisons of resource use, and clinical and functional outcomes.

METHODS

This post hoc analysis of a one-year, multicentre, prospective, observational study included outpatients with schizophrenia who required a change in their antipsychotic medication because of a physician-perceived risk of medication non-adherence. Patients were matched 1 : 1 using an optimal algorithm with rank-based Mahalanobis distances. All-cause medication discontinuation was compared using the Klein and Moeschberger test for survival and hazard ratios (HR) with 95% confidence intervals (CI) were calculated using a Cox proportional hazards model, stratifying on matched pairs.

RESULTS

Forty patients who initiated a depot antipsychotic could be matched to patients who initiated an oral antipsychotic. Fewer depot-treated patients discontinued their antipsychotic medication at least once compared with oral-treated patients [20% (8/40) vs. 40% (16/40)]. Depot-treated patients discontinued their medication later (Klein and Moeschberger test p = 0.025) and were less likely to discontinue their initial antipsychotic medication [HR = 0.33 (95% CI, 0.12-0.92), p = 0.033] than oral-treated patients. There were few differences in resource use and no differences in clinical and functional outcomes between cohorts.

CONCLUSION

In this matched-cohort analysis, patients with schizophrenia who were considered to be non-adherent with their prior oral antipsychotics were less likely to discontinue their medication for any cause if they were initiated on depot compared with oral antipsychotics.

Assessing the infrequent oral supplementation of olanzapine long-acting injection in the treatment of schizophrenia

OBJECTIVE

Adding another antipsychotic to a treatment regimen was previously used in evaluating the medication's efficacy. Supplementation of depot antipsychotics with oral antipsychotics is particularly meaningful because depot formulations are typically chosen for patients struggling with adherence to oral antipsychotics. This post-hoc analysis assessed supplementation of olanzapine long-acting injection (olanzapine-LAI) with oral olanzapine.

SUBJECTS AND METHODS

We used 12 months of data from an open-label, single-arm extension study of patients with schizophrenia or schizoaffective disorder (N=931) treated with olanzapine-LAI. The prevalence, duration, time to first supplementation, and best predictors of oral supplementation were assessed.

RESULTS

Oral supplementation occurred in 21% of patients for a median of 31 days with mean modal dose of 10.8 mg/day. Mean time to first supplementation was shorter for patients who were at least moderately ill at baseline compared to less ill patients (47 vs. 97 days, p<0.001). Best predictors of oral supplementation included a more severe illness profile at baseline, lower olanzapine-LAI dose prior to oral supplementation, supervised living arrangements, and being African-American.

CONCLUSION

Supplementation of olanzapine-LAI appears to be infrequent, of relatively short duration, and reserved for more severely ill patients who may require a targeted rescue medication due to signs of impending relapse.

A prospective study of the impact of subthreshold mixed states on the 24-month clinical outcomes of bipolar I disorder or schizoaffective disorder

OBJECTIVES

The clinical significance of subthreshold mixed states is unclear. This study investigated the clinical outcomes in participants with bipolar I disorder or schizoaffective disorder, using the Cassidy and Benazzi criteria for manic and depressive mixed states, respectively.

METHODS

Participants (N=239) in a prospective observational study of treatment and outcomes in bipolar I or schizoaffective disorder, bipolar type, were grouped based on study entry clinical presentation as having pure depression (n=63) if they satisfied DSM-IV-TR criteria for a Major Depressive Episode (MDE), depressive mixed state if they also had at least three concurrent hypomanic symptoms (n=33), or not depressed (n=143) if they did not satisfy the criteria for MDE. Participants were similarly grouped as having pure mania (n=3) if they satisfied DSM-IV criteria for a Manic Episode, manic mixed state if they also had at least two concurrent depressive symptoms (n=33), or not manic (n=203). Clinical data were collected by interview every 3 months over a 24-month period.

RESULTS

Measures of quality of life, mental and physical health over the 24-month period were significantly worse for participants who were classified as having mixed states at study entry on most outcome measures compared to participants who were not in an illness episode at study entry. A depressive mixed state was predictive of greater manic symptomatology over the 24 months compared to participants with pure depression.

CONCLUSION

In participants with a current episode of mood disorder, the presence of subthreshold symptoms of opposite polarity was associated with poorer clinical outcomes over a 24-month period.

Worldwide-Schizophrenia Outpatient Health Outcomes (W-SOHO): baseline characteristics of pan-regional observational data from more than 17,000 patients

OBJECTIVE

To describe the Worldwide-Schizophrenia Outpatient Health Outcomes (W-SOHO) patient population at study entry, focusing on illness burden and prescribing practices across regions.

METHODS

The SOHO study was a 3-year, prospective, observational study designed to assess costs and outcomes associated with antipsychotic use in outpatients initiating or changing antipsychotic (with an emphasis on olanzapine compared with other antipsychotics). SOHO was conducted in 10 European countries and 27 other countries as Intercontinental SOHO (IC-SOHO). Data from all countries have been pooled to produce the W-SOHO dataset.

MAIN OUTCOMES MEASURES

Clinical Global Impression-Schizophrenia (CGI-SCH) severity scores, psychotropic medication use, adverse events, social interaction, housing and employment status, self-perceived health state (EuroQoL EQ-5D scale and Visual Analogue Scale, EQ-VAS), and reasons for initiation/change of antipsychotic.

RESULTS

The W-SOHO database comprises 17,384 patients from six regions; East Asia (n = 1223), Central and Eastern Europe (n = 2175), Northern Europe (n = 4291), Southern Europe (n = 5788), Latin America (n = 2566), North Africa and the Middle East (n = 1341). Overall, patients were 38 +/- 13 years old (mean +/- SD), moderately ill (mean CGI-SCH overall score of 4.4 +/- 1.0) with a median duration of illness of 7 years (interquartile range 1-16 years); 43% were female, 10% were receiving antipsychotic medication for the first time. Adverse events were prevalent across all regions; on average, 50% (range 41-59%) of patients taking antipsychotics exhibited extrapyramidal symptoms at baseline, and 62% (34-67%) of patients reported sexual dysfunction in the previous month. On average, only 19% (16-23%) of patients were in paid employment and as many as 69% were living in dependent housing.

CONCLUSIONS

Despite inherent diversity in these patients and the health care systems supporting them, there are striking cross-regional similarities in baseline characteristics for most measures. Not all countries are represented; regional comparisons may not be valid outside of the countries studied.

History of illness prior to a diagnosis of bipolar disorder or schizoaffective disorder

BACKGROUND

There are obstacles to early identification of bipolar disorder. Identifying and treating illness early in its time course may be associated with a better prognosis.

METHODS

A questionnaire was administered at interview, when the participant was euthymic, to participants (n=240) enrolled in the Bipolar Comprehensive Outcomes Study (BCOS). Information was collected about the sequential timeline of specific symptoms of mental illness up to when they first received a diagnosis of Bipolar Disorder or Schizoaffective Disorder.

RESULTS

Any symptoms of mental illness were first experienced at 17.5 years (median; Inter Quartile Range (IQR) 13.8-24.3; n=216) and mood swings at 18.0 years (IQR 14-25; n=197). Symptoms of depression were experienced at 18.0 years (IQR 14-25; n=197), a full episode of depression at 21.2 years (IQR 17-28.5; n=200), symptoms of mania at 21.0 years (IQR 16.8-29.5; n=212) and a full episode of mania at 24.1 years (IQR 19-30.5; n=205). Medical treatment was sought at 24.0 years (IQR 19-31.5; n=217). Participants received a diagnosis of Bipolar Disorder or Schizoaffective Disorder at 30.0 years (IQR 23-37.3; n=215). Having had a previous diagnosis other than Bipolar Disorder or Schizoaffective Disorder was reported by 120 of 216 participants who answered this question, most commonly unipolar depression (26.6%). Diagnostic delay was greater in individuals with early onset disorder.

CONCLUSIONS

Participants typically experience a long sequential course of symptoms, episodes, treatments and diagnosis. The polarity of onset is most commonly depressive, and subthreshold symptoms tend to precede threshold symptoms of both polarities.

LIMITATIONS

Data were collected retrospectively.

Melting Curve and High-Pressure Chemistry of Formic Acid to 8 GPa and 600 K

We have determined the melting temperature of formic acid (HCOOH) as a function of pressure to 8.5 GPa using infrared absorption spectroscopy, Raman spectroscopy and visual observation of samples in a resistively heated diamond-anvil cell. The experimentally determined incongruent melting curve compares favorably with a two-phase thermodynamic model. Decomposition reactions were observed above the melting temperature up to a pressure of 6.5 GPa, with principal products being CO2, H2O, and CO. At pressures above 6.5 GPa, decomposition led to reaction products that could be quenched as solids to zero pressure, and infrared and Raman spectra indicate that pressure leads to the presence of sp3 carbon-carbon bonding in these reaction products.

The role of postradiotherapy neck dissection in supraglottic carcinoma

PURPOSE

To evaluate our policy of performing neck dissection based on regional response after definitive radiotherapy in patients with supraglottic carcinoma and to identify the prognostic factors in this group of patients.

METHODS AND MATERIALS

Between 1970 and 1995, 121 patients with node-positive squamous cell carcinoma of the supraglottic larynx were treated with definitive radiotherapy. Sixty-nine percent of patients presented with 1997 AJCC Stage IV disease. The N-stage distribution was N1, 49; N2, 62; and N3, 10. The median size of the lymph nodes was 3 cm (range, 0.5-8 cm). Forty-five patients received once-a-day treatment with a median total dose of 65 Gy (range, 58.0-70.8 Gy) in 1.8-2.0 Gy per fraction over 48 days, and 76 patients received split-course accelerated hyperfractionation with a median total dose of 67.2 Gy (range, 63.2-73.6 Gy) in 1.6 Gy twice a day over 43 days. Patients whose lymph nodes were not clinically detectable at 4-6 weeks after the completion of radiotherapy (complete response) were followed without any neck dissection. Patients with persistent neck adenopathy (partial response) underwent neck dissection whenever possible. Mean follow-up of the living patients was 6.5 years.

RESULTS

Regional response was related to the size of lymph nodes at presentation. Eighty-seven percent of patients with nodal size of 3 cm or less had a complete response, whereas 43% of patients with nodal size greater than 3 cm had a partial response. The rate of regional control at 3 years for all patients in the study was 66%. The 3-year ultimate regional control rate after salvage neck dissection was 75%. A relapse in both the primary and regional sites was the most common pattern of relapse, accounting for 39% of all the failures. Local failure was associated with subsequent regional relapse with a relative risk of 4.3. For patients with complete response in whom postradiotherapy neck dissection was withheld, the regional control rates were 75% and 86% for N1 and N2, respectively. The rate of isolated regional relapse in this group of patients was 7.5%. In multivariate analysis, significant favorable factors predictive for regional control were female gender, accelerated hyperfractionation, and complete response; whereas factors predictive for overall survival were Karnofsky Performance Scale score and regional response. The rate of Radiation Therapy Oncology Group (RTOG) Grade 2 or 3 neck fibrosis was 17% and 23% for patients with and without postradiotherapy neck dissection, respectively.

CONCLUSION

Isolated regional relapse is not common in patients with supraglottic carcinoma when a complete response is achieved at 4-6 weeks after definitive radiotherapy and postradiotherapy neck dissection is not performed. Female gender, accelerated hyperfractionation, and complete response are favorable predictors of regional control.

Apoptosis-induced by TRAIL AND TNF-alpha in human multiple myeloma cells is not blocked by BCL-2

TRAIL, the ligand for the newly discovered DR-4 and DR-5 receptor is a member of the tumour necrosis factor (TNF) family of death signal tranduction proteins with a mechanism of cell death, similar to the Fas and Fas ligand (Fas-L) system. Here, we provide first time evidence that TRAIL and TNF-alpha are potent inducers of apoptosis in multiple myeloma (MM) cell lines and freshly isolated myeloma cells. TRAIL effectively induced extensive apoptosis in 8226 and ARP-1 MM cells in a time- and dose-dependent manner reaching 80% within 48 h of treatment with a dose of 160 ng/ml. Bcl-2 transfected 8226 and ARP-1 cells were equally sensitive to apoptosis by TRAIL. Apoptosis with TNFalpha, reached >60% within 48 h of treatment with a dose of 160 ng/ml. In addition to MM cell lines, freshly isolated, flow-sorted myeloma cells from 8 different MM patients expressing variable levels of bcl-2 were equally sensitive to both TRAIL and TNF-alpha. We have previously shown that anti-Fas-induced apoptosis is not blocked by endogenous or ectopic bcl-2 in MM cell lines. Here we extend our observation with Fas to include TNF-alpha and TRAIL to the apoptotic signals that are not be blocked by bcl-2, in MM cells.

Successful PBSC mobilization with high-dose G-CSF for patients failing a first round of mobilization

PBSC are the preferred source of stem cells for autologous transplantation. However, regardless of the mobilization procedure used, 10%-20% of patients fail to collect an adequate number to ensure prompt engraftment. There is as yet no standard mobilization procedure for patients who fail a first mobilization attempt. Here, we describe a highly efficient strategy to obtain an adequate number of stem cells for patients who failed a first mobilization attempt. Seventy-four patients with various hematologic malignancies underwent initial mobilization with various regimens including hematopoietic growth factors with or without chemotherapy. In 72% of patients, > or =2 x 10(6) CD34+ stem cells/kg were collected in the initial mobilization attempt, and patients engrafted in a median of 10 days for neutrophils and 12 days for platelets. Eighteen patients failed to mobilize adequate numbers of stem cells, defined as the inability to collect 0.2 x 10(6) CD34+ stem cells/kg/day in the first 2-3 days. These patients had their apheresis halted. Patients were immediately given G-CSF (32 microg/kg/day) for 4 days as a second attempt at mobilization. Eighty-eight percent of these patients achieved the target of > or =2 x 10(6) CD34+ cells/kg, with a median duration of apheresis of 5 days (including the first and second mobilizations). The mean CD34+ cells/kg/day increased after administration of high-dose G-CSF from 0.16 after the first mobilization attempt to 0.61 (p = 0.0002) after the second mobilization. All patients engrafted in a median of 11 and 13 days for neutrophils and platelets, respectively. We conclude that patients whose apheresis yield is <0.4 x 10(6) CD34+ cells/kg after the first two apheresis collections can be successfully mobilized if high-dose G-CSF is administered immediately and continued until achieving > or =2 x 10(6) CD34+ stem cells/kg.

Results of accelerated radiotherapy for supraglottic carcinoma: a Massachusetts General Hospital and Massachusetts Eye and Ear Infirmary experience

BACKGROUND

Carcinoma of the supraglottic larynx is a relatively common malignancy treated with either surgery, radiotherapy, or a combined approach.

METHODS

The radiotherapy records of 190 patients with carcinoma of the supraglottic larynx treated at the Massachusetts General Hospital (MGH) and Massachusetts Eye and Ear Infirmary (MEEI) from 1981 to 1992 were reviewed. Of these patients, 164 were available for evaluation for local control and 169 for disease-specific survival. The patients were treated with accelerated hyperfractionated radiotherapy to 67.2-72 Gy/1.6 Gy per fraction twice a day in 6 weeks. The median follow-up was 56 months. Five-year actuarial local and regional control, relapse-free and overall survival, and voice-preservation rates were analyzed.

RESULTS

For T1, T2, T3, and T4 tumors, local control rates were 96%, 86%, 76%, and 43%, respectively (p < .01), and the corresponding relapse-free survival rates were 78%, 82%, 64%, and 40% (p < .01). For the patients with N0, N1, and N2-3 disease, local control rates at the primary site were 86%, 74%, and 46%, respectively (p < .01), and the corresponding relapse-free survival rates were 79%, 53%, and 39% (p < .01). Including surgical salvage, the ultimate local control rates were 96%, 93%, 88%, and 51%, respectively (p < .01). Voice preservation rate for the entire group was 79% and for T1, T2, T3, and T4 tumors, rates were 96%, 80%, 72%, and 43%, respectively.

CONCLUSIONS

Our experience with accelerated hyperfractionated radiotherapy for supraglottic carcinoma showed excellent locoregional control, relapse-free survival, and laryngeal preservation. The radiation toxicity was acceptable. The T and N stages were significant predictors of outcome, and the T4 tumors and node-positive neck disease portended a poor prognosis and therefore should be considered for protocols that include adjuvant therapies.

Double grafting of the left anterior descending artery: is the distance between the internal mammary artery and supplemental vein graft anastomoses relevant in graft survival?

INTRODUCTION

Under certain conditions (small internal mammary artery (IMA) or large runoff), double grafting of the left anterior descending (LAD) artery system is necessary to avoid the ominous consequences of myocardial hypoperfusion. Previous studies have shown that a saphenous vein (SVG) adjacent to an IMA graft leads to failure of the IMA. This study compares IMA flow patterns when adjacent ( < 1 cm) and separated (3-4 cm) from a SVG placed on a proximally occluded LAD.

METHODS

A SVG and right IMA (PIMA) to proximal LAD (2.5-3 mm) coronary bypass were performed in 12 mongrel dogs. The left IMA (DIMA) was anastomosed to the distal LAD (1.5 mm). All anastomoses were carried out without cardiopulmonary bypass. The native LAD was occluded proximally to the PIMA anastomosis, and all graft flows were measured in competitive and non-competitive flow conditions.

RESULTS

Isolated graft to LAD flows were similar for the three conduits. There was a drop in flow in both the PIMA and DIMA when placed in competition with the SVG (10.1+/-3.0 vs. 19.1+/-4.6 ml/min; P < 0.05). The total drop in flow was significantly greater in the PIMA (67.6 vs. 39.9%; P < 0.05). Diastolic flow was better preserved in the distal IMA graft (19.6 + 5.6 vs. 10.2+/-3.0 ml/min; P < 0.05). The patterns of flow were much different during competition and there was significant retrograde systolic flow in all PIMA grafts while there was no (n = 5) or minimal retrograde flow (n = 7) in the DIMA grafts.

CONCLUSION

An IMA graft, when adjacent to a SVG, sustains a significant decrease in both total and diastolic flows and develops an oscillating pattern of flow in early systole (retrograde then antegrade). Placing the IMA more distally on the LAD improves flow and decreases retrograde flow. In clinical situations requiring double grafting on the LAD, distance between grafts may be an important factor in maintaining IMA patency.

Variable effects of cardiomyoplasty on left ventricular function

Cardiomyoplasty (CMP) has been considered as a possible treatment for patients with heart failure. Symptomatic improvements occur almost uniformly among survivors with CMP, but changes in left peak ventricular systolic pressure (PVSP) and stroke volume vary in patients. This study examined whether there is variability present shortly after cardiomyoplasty surgery. Cardiomyoplasty was performed in 11 mongrel dogs with normal ventricular function. Nine to twelve days after CMP, left ventricular (LV) function was evaluated by simultaneously measuring LV volume (conductance catheter) and pressure (Millar catheter). The latissimus dorsi muscle (LDM) was stimulated synchronously with ventricular systole in a ratio of 1:4 to 1:7 to avoid muscle fatigue. Data were analyzed on a beat by beat basis. The PVSP, and maximum dP/dt (+dP/dt) increased, but the absolute value of minimum dP/dt (-dP/dt) decreased in stimulated beats in 7 dogs while 4 dogs did not respond. The net changes in stimulated beats versus nonstimulated beats of PVSP were 6.1 +/- 1.8 mm Hg (4.3%), of stroke work was 4.5 +/- 1.9 gm x m (29.5%), of +dP/dt was 185 +/- 47 mm Hg/s (8%), and of -dP/dt was 168 +/- 43 mm Hg/s (7.8%) (p < 0.05) for all these net changes in the responding group while these variations were not significant in the nonresponding group. From the results of our study, active LDM assist improves left ventricular systolic function, occurring in only 7 of 11 experiments. This improvement is inconsistent and varied individually. The integrity of the LDM, tightness of wrapping, and adhesions might contribute to the variability which is present early after surgery and before the LDM is converted into a fatigue resistance muscle.

Factors affecting internal mammary artery graft survival: how is competitive flow from a patent native coronary vessel a risk factor?

Recent studies have suggested that competitive flow is an important factor in early internal mammary artery (IMA) graft failure. Flow competition from minimally diseased native coronary vessels has been implicated in the failure of IMA grafts, but does not seem to affect saphenous vein grafts (SVG). The objective of this study was to determine the effects of competitive flow on SVG and IMA grafts and to compare the patterns of flow dynamics and pressure on proximal and distal grafts to the left anterior descending (LAD) artery; factors that may be involved in graft failure. Twelve mongrel dogs underwent coronary artery bypass grafting using IMAs and a SVG to an open LAD artery. The right IMA (PIMA) and the SVG were anastomosed in the proximal LAD and the left IMA (DIMA) was anastomosed at a more distal location. The procedure was performed through a left thoracotomy, using an "off pump" technique. Graft flows were measured isolated and in competition. The IMAs and SVG provided flow levels similar to the native LAD when each one was the sole inflow to the LAD. During competitive flow conditions, total and diastolic SVG flows were reduced 54.4 and 50.5%, respectively (P < 0.05). Total and diastolic PIMA and DIMA flows were reduced more drastically (68.6-73.3 and 69.5-68.1%, respectively; P < 0.05). The DIMA had better preservation of diastolic flow compared to PIMA. A delay in the pressure wave was noted in the isolated IMAs, but not in the SVG. This pattern of flow disappeared during competition due to the large, systolic retrograde flow up the IMA grafts. In conclusion, IMAs compared to the SVG are longer and narrower conduits with lower levels of flow during competition. Low levels of flow and oscillating flow (retrograde/ antegrade) may be poorly tolerated by the IMA endothelium and may be factorial to graft failure. These data suggest that a more distal placement of the IMA graft may be protective to the arterial graft under competitive flow conditions.

ITA versus SVG: a comparison of instantaneous pressure and flow dynamics during competitive flow

OBJECTIVE

Competitive flow from patent native coronary vessels is implicated in the failure of internal thoracic artery (ITA) grafts, but it is not thought to affect saphenous vein graft (SVG) patency. This study examines instantaneous pressure and flow dynamics in left ITA and SVG grafts in competition with a patent left anterior descending (LAD) artery.

METHODS

SVG (3.0-4.0 mm) and ITA (1.5-2.0 mm) to proximal LAD (2.5-3.0 mm) coronary bypass was performed in 10 mongrel dogs. Flow and pressure were measured in the occluded (No Competition) and opened (Competition) ITA, SVG and LAD.

RESULTS

The ITA and SVG, when each was the sole inflow to the LAD, provided similar flow as the native LAD. During competitive flow, total LAD flow was preserved and flow in the ITA and SVG were reduced (8.20 +/- 1.25 and 10.00 +/- 1.73 ml/min; P < 0.005). SVG diastolic flow was reduced to 11.52 +/- 2.17 ml min (55.5%); P < 0.003. Flow in the SVG remained predominantly antegrade. In contrast, ITA diastolic flow was reduced more drastically, to 5.37 +/- 1.25 ml/min (80.7%); P < 0.0001. When the ITA was the only inflow to the LAD, there was delay in the LAD pressure wave. This delay disappears during competition due to the large, systolic retrograde flow up the ITA.

CONCLUSION

The ITA, compared to the SVG, is a longer and narrower conduit with lower levels of flow during competition. Due to a delay in the pressure wave, the ITA flow is retrograde during early systole. Low levels of flow, with a markedly decreased diastolic phase, and the oscillating pattern in systole (retrograde/antegrade) may be poorly tolerated by the ITA endothelium and lead to graft deterioration.

Revision total knee arthroplasty with use of modular components with stems inserted without cement

We reviewed the results of seventy-six revision total knee replacements, performed between 1980 and 1988 on the Knee Service at The Hospital for Special Surgery, in seventy-four patients. Sixty-five patients (sixty-seven knees; 88 percent) had a complete clinical examination and radiographic evaluation, and nine patients (nine knees; 12 percent) were only interviewed by telephone. Survivorship analysis was performed for all patients. The average duration of follow-up was three years and six months (range, two to nine years). Only patients who had had revision of the femoral component or the tibial component, or both, because of aseptic failure were included. The tibial component of all prostheses that were used for revision had a metal backing. Cement was placed on the cut surfaces in the metaphyseal region of the femur and tibia. Fluted diaphyseal intramedullary rods were used in all patients and were not cemented. Metal wedges and augments were used to fill osseous defects when necessary. The average preoperative knee score, according to the rating scale of The Hospital for Special Surgery, was 49 points (range, 0 to 62 points). Postoperatively, the knee score improved to an average of 76 points (range, 0 to 97 points). Of the sixty-seven knees that had complete follow-up, fifty-six (84 percent) had an excellent or good result and five (7 percent) had a fair or poor result. In six (8 percent) of the seventy-six knees, the prosthesis failed, necessitating another revision. Failure was defined as removal or a recommendation for removal of the implant.(ABSTRACT TRUNCATED AT 250 WORDS)

Midforehead incision: an approach to the frontal sinus and upper face

The coronal incision has established itself as the principal surgical approach to the forehead. It allows for a well-hidden scar and a wide field of surgical exposure. The midforehead incision, described in the brow-lift literature, is a cosmetically acceptable alternative to the coronal incision for patients with forehead wrinkles or who are at risk for male pattern baldness. In an analysis of 33 consecutive open frontal sinus procedures, we compared patients who underwent i coronal approach to a midforehead approach for operative time, blood loss, length of hospital stay, and cosmetic result. There was a trend toward decreased operative time and decreased blood loss with the midforehead approach. The cosmetic result was acceptable in all patients. We advocate the use of a midforehead approach to the frontal sinus in patients with deep forehead creases and with hairline recession and elderly or infirmed patients who cannot tolerate prolonged procedures or significant blood loss.

Antibiotic penetration of experimental intra-abdominal abscesses

Intra-abdominal abscess is seldom adequately treated by systemic antibiotics alone and often requires surgical or computed tomography-guided drainage for resolution. Abscess penetration of six currently used antibiotics was examined in a murine intra-abdominal abscess model. Ampicillin/sulbactam, cefmetazole, clindamycin, and trospectomycin penetrated intra-abdominal abscesses to a greater degree than cefoxitin and ceftriaxone. Abscess pus antibiotic levels were not significantly higher after multiple doses than after a single dose. Pus antibiotic levels below the MIC90 for Bacteroides and E. coli within intra-abdominal abscess were observed for most antibiotics with the doses used in this study. Selection of antibiotics with a greater ability to penetrate abscess may be important in optimally treating patients with abdominal infection.

Local control of oropharyngeal carcinoma by irradiation alone

The authors of this study reviewed the management of 402 patients with squamous cell carcinomas of the faucial tonsil and the base of the tongue. These patients received radiation therapy at Massachusetts General Hospital and the Massachusetts Eye and Ear Infirmary from 1970 through 1993. Radiation therapy remains the treatment of choice for these lesions. Although the data from this review were not randomized, the accelerated hyperfractionated radiation therapy twice-daily program was shown to achieve significantly higher 5-year local tumor control rates and disease-specific survival rates than the conventional once-daily radiation therapy program (historical control). In patients with early tumors of the faucial tonsil (cancer stages T1 and T2), the 5-year actuarial local tumor control and disease-specific survival rates following the twice-daily radiation therapy program were 91% and 77%, respectively. In patients with advanced tumors (T3), the corresponding rates following twice-daily radiation therapy showed marked improvement and were 80% and 68%. While the treatment results for carcinoma of the base of the tongue generally were inferior to those for carcinoma of the faucial tonsil, they were still much better after the twice-daily program than after conventional once-daily irradiation. For patients with carcinoma of the base of the tongue, the local tumor control and disease-specific survival rates for T1 and T2 lesions were 85% and 76%, respectively. For T3 lesions, the corresponding rates were 54% and 53%. Extensive T4 tumors are better managed by combined surgery and postoperative irradiation. Residual metastatic nodal disease is managed by neck dissection.

Use of the stable peptide, gamma-L-glutamyl-L-tyrosine, as an intravenous source of tyrosine in mice

The relative insolubility of tyrosine (Tyr) at neutral pH limits amounts of this amino acid in solutions used for total parenteral nutrition (TPN). We have tested the potential of the natural peptide, gamma-L-glutamyl-L-tyrosine (Glu(Tyr], to release Tyr in vivo by making 20-microL injections, containing 2.9 mumol Glu(Tyr) (approximately 80 mumol/kg body weight), into the external jugular veins of mice. Mean concentrations of Glu(Tyr) in plasma were 138.5 and 11.4 mumol/L after 10 and 60 minutes, respectively; plasma Tyr was significantly elevated at 10 minutes, but returned to control levels at 60 minutes. When 5.8 mumol of Glu(Tyr) was injected, levels of Glu(Tyr) and of Tyr were significantly higher at both 10 and minutes than when 2.9 mumol of peptide was injected. Animals showed no evidence of toxicity. Two percent or less of the peptide could be detected in the urine, even in mice injected with 5.8 mumol Glu(Tyr). Pretreatment of mice with acivicin, a potent inhibitor of gamma-glutamyl transpeptidase (GGTase), prevented the increase in plasma Tyr seen after injection of 2.9 mumol Glu(Tyr) and led to higher levels of Glu(Tyr) in the plasma both at 10 and at 60 minutes than seen in mice given the same amount of Glu(Tyr) but no acivicin. The presence of the inhibitor also led to loss of as much as 48% of the administered peptide in the urine in 60 minutes. These data suggest that GGTase catalyzes hydrolysis of intravenous (IV) Glu(Tyr) to release Tyr in vivo. Glu(Tyr) in the blood is not partitioned into red blood cells; it remains in the plasma, available to GGTase, which functions at the external surface of cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Tumor necrosis factor-alpha and hematopoietic progenitors: effects of tumor necrosis factor on the growth of erythroid progenitors CFU-E and BFU-E and the hematopoietic cell lines K562, HL60, and HEL cells

Macrophages can modulate the growth of hematopoietic progenitors. We have examined the effects of tumor necrosis factor-alpha, a product of activated macrophages, on human erythroid progenitors (CFU-E, BFU-E) and the hematopoietic cell lines K562, HL60, and HEL cells. Tumor necrosis factor (TNF) significantly inhibited CFU-E and BFU-E growth at concentrations as low as 10(-11)-10(-12) M (0.2 U/ml), although erythroid colony and burst formation were not totally ablated. Preincubation of marrow samples with TNF for 15 min was sufficient to suppress erythroid colony and burst formation. Addition of TNF after the start of culture inhibited CFU-E- and BFU-E-derived colony formation if TNF was added within the first 48 h of culture. Additionally, TNF inhibited the growth of highly purified erythroid progenitors harvested from day 5 BFU-E. The colonies which formed in cultures treated with TNF were significantly smaller than those formed in control cultures. TNF (10(-8)-10(-10) M) also suppressed the growth of the hematopoietic cell lines K562, HL60, and HEL cells, with 40%-60% of the cells being sensitive to TNF. Preincubation of HL60 cells with TNF for 15 min significantly inhibited their growth. K562, HL60, and HEL cells expressed high-affinity receptors for TNF in low numbers (6000-10,000 receptors per cell). Fluorescence-activated cell sorter analysis of TNF binding to HEL cells demonstrated that the majority of these cells expressed TNF receptors. These data suggest that: (1) TNF is a rapid irreversible and extremely potent inhibitor of CFU-E, BFU-E, and hematopoietic cell lines K562, HL60, and HEL cells; (2) TNF appears to be acting on a subpopulation of erythroid cells, predominantly CFU-E, BFU-E, and possibly proerythroblasts; (3) TNF appears not to require accessory cells such as lymphocytes or macrophages to inhibit erythroid progenitors; and (4) the presence of TNF receptors on hematopoietic cells is not sufficient to confer sensitivity to TNF since the majority (80%-95%) of HEL cells express TNF receptors while only 40%-60% are inhibited by TNF.

An integrated perinatal information system and telecommunications networking

The integrated perinatal information system in Albany Medical Center has two significant features: that of a flexible user-definable database and ease of networking both locally and regionally. The unified perinatal record is structured in Ansi standard MUMPS and resides on the College Vax 750. A special set of program tools ensures effective multi-split screen display, moving pointers, and corresponding multiple choice entries. Because it is self contained, it has the ability to create complex data structures without programming. A powerful math/statistical library has been incorporated. In house, the use of existing PABX wire allows for simultaneous voice/data traffic. Linkage to the regional system is made by modem connection. The system is compatible with the demands of both clinical and regional management.

Pharmacology and inotropic potential of forskolin in the human heart

We evaluated the effects of the diterpene compound forskolin in human myocardial adenylate cyclase preparations, isolated trabeculae and papillary muscles derived from failing human hearts, and acutely instrumented dogs. Forskolin was a potent, powerful activator of human myocardial adenylate cyclase and produced maximal effects that were 4.82 (normally functioning left ventricle) and 6.13 (failing left ventricle) fold greater than isoproterenol. In contrast to isoproterenol, forskolin retained full activity in membrane preparations derived from failing hearts. In cyclase preparations, forskolin demonstrated unique substrate and Mg2+ kinetic properties that could be distinguished from hormone receptor-coupled agonists or fluoride ion. The adenylate cyclase stimulatory effect of forskolin was synergistic with isoproterenol, apparently due to the location of forskolin activation being beyond the level of hormone receptor-agonist in the receptor-cyclase complex. Forskolin was a potent positive inotrope in failing human myocardium, producing a stimulation of contraction that was similar to isoproterenol. Finally, in open chest dogs forskolin was a positive inotropic agent that reduced preload and afterload. We conclude that forskolin belongs to a class of agents that may have therapeutic potential in the treatment of congestive heart failure.

Role of ventrolateral medulla in vasomotor regulation: a correlative anatomical and physiological study

Two groups of experiments were carried out in rabbits. First, the ventrolateral reticular formation of the medulla oblongata was stimulated either by microinjection of sodium glutamate solution (exciting only cell bodies) or electrically (exciting cell bodies and axons). This region has been shown previously to contain a dense and compact group of bulbospinal cells. The effects of both electrical and chemical stimulation of specific sites were correlated with the density of ventrolateral bulbospinal cells at the same sites. Glutamate microinjection into the center of the group of bulbospinal cells elicited a very large and sustained increase in arterial pressure, whereas microinjection into sites outside this region elicited a very small or no response. These results suggest that it is the bulbospinal ventrolateral cells which mediate the pressor response to glutamate stimulation. Focal electrical stimulation in the ventrolateral medulla elicited increases in arterial pressure and decreases in femoral and renal vascular conductance, as well as a short-latency increase in renal sympathetic nerve activity. The most effective sites for focal electrical stimulation lay within the region of greatest density of bulbospinal cells; slightly less effective sites lay just rostral and caudal to this region. It is suggested that stimulation in these latter sites predominantly excites axons of passage. Secondly, the origin of afferent fibers to the ventrolateral vasomotor area was studied using the horseradish peroxidase (HRP) method. This revealed major projections from the medial part of the nucleus tractus solitarius and the parabrachial nucleus in the pons. The physiological and anatomical studies taken together are consistent with the hypothesis that the bulbospinal ventrolateral cells are vasomotor in function, and receive afferent inputs from brain stem nuclei which are known to play a role in autonomic regulation.

Cartilaginous tumors of the larynx

Laryngeal cartilaginous tumors are well-defined masses that arise within the endolaryngeal structures, predominantly the cricoid cartilage. Twelve cases with long-term followup are reviewed. The importance of early and complete radiological evaluation and the potential for recurrence is emphasized. Since metastases or extralaryngeal extension is rare, conservative surgery, preserving laryngeal function as long as possible, is the treatment of choice. The histological distinction of chondroma versus chondrosarcoma is not essential for the clinical management of these lesions, and we suggest they be designated as cartilaginous tumors of the larynx.

Pathologic findings in gouty cricoarytenoid arthritis

The clinical manifestations of cricarytenoid joint gouty arthritis have been previously reported. They include hoarseness, dysphagia, and dysphonia. Exacerbation of gouty laryngeal arthritis can accompany multiple joint involvement or appear as a single joint manifestation. The development of laryngeal symptoms in the patient with arthritix calls for prompt indirect laryngoscopy. The phonatory and sphincteric functions of the larynx are severely altered by limited cricoarytenoid joint fixations.