Bleeding reflux esophagitis: a prospective 1-year study in a university hospital

OBJECTIVES

The prevalence of bleeding from reflux esophagitis has not been studied. The aim of the study was to evaluate the 1-yr prevalence of bleeding from reflux esophagitis, as well as the independent factors associated with bleeding.

METHODS

All patients with reflux esophagitis diagnosed with upper digestive tract endoscopy in Reims Hospital in 1996 were included. Studied parameters were prospectively recorded and compared between patients with bleeding and nonbleeding reflux esophagitis.

RESULTS

Endoscopy was performed in 1983 patients of whom 219 (11.0%) had overt upper digestive tract hemorrhage. Reflux esophagitis was the cause of bleeding in 32 patients (14.6%). Reflux esophagitis was diagnosed in 391 patients during the same period of time. Bleeding reflux esophagitis accounted for 8.2% of them. Independent factors associated with bleeding were grade 3 or 4 (Savary-Miller) esophagitis (odds ratio [OR]: 25.5, 95% confidence interval [CI]: 9.6-67.9), cirrhosis (OR: 5.7, 95% CI: 1.7-18.9), Eastern Cooperative Oncology Group performance status > or = 3 (OR: 4.6, 95% CI: 1.5-14.2), and anticoagulant therapy (OR: 3.9, 95% CI: 1.2-12.5). A history of reflux esophagitis or heartburn was noted in only 28.1% or 37.5% of the patients with bleeding reflux esophagitis, respectively.

CONCLUSIONS

In this population of patients with reflux esophagitis, the prevalence of bleeding esophagitis was high (8.2%). Bleeding esophagitis occurred primarily in patients with severe esophagitis and was the revealing clinical form of gastroesophageal reflux disease in the majority of cases, suggesting that bleeding prevention would hardly be effective.

[Peripheral stem cell collection, search for predictive factors: a multicenter study. Working Group on Transfusion and Therapeutic Techniques of the French Blood Transfusion Society ]

AIMS

A multicentric study involving 12 centers was made to investigate the results of peripheral stem cell collection carried out between 1996 and 1997 from 655 patients with hemopathic syndromes or malignant tumors, The aim of this investigation was to determine the predictive factors for transplant quality, and to thereby optimize collection procedures.

PATIENTS AND METHODS

Information sheets were completed for 1,346 cytapheretic sessions, i.e., 655 grafts. The samples were taken after induction chemotherapy and exposure to hematopoeitic colony-stimulating growth factors (except the LMCs). Each graft was defined as being of good or bad quality depending on the number of CD34+ cells that it contained. Based on the data available in the literature, a workgroup consensus was reached that a level of CD34+ cells +/- 2.10(6)/kg recipient body weight constituted a good transplant criterion. The 2 subgroups (good graft versus lower quality graft) were compared by univariate analysis followed by discriminant multivariate analysis.

RESULTS

It was established that a number of parameters were significantly linked to the criterion of collection quality; however, 3 predictive factors emerged from the multivariate analysis--the level of circulating CD34+ cells; the number of cytaphereses; the number of blood volumes treated.

CONCLUSION

It was concluded that the level of circulating CD34+ cells seems to be an essential aspect in predicting the quality of the transplant and the number of cytaphereses required to obtain a sufficiently rich collection. Moreover, it also appears that at least 2 blood volumes should be treated to optimize the results.

Transduction of murine cerebellar neurons with recombinant FIV and AAV5 vectors

Our data demonstrate that vectors derived from recombinant feline immunodeficiency virus (rFIV) and adeno-associated virus type 5 (rAAV5) transduce cerebellar cells following direct injection into the cerebellar lobules of mice. Both recombinant viruses mediated gene transfer predominantly to neurons, with up to 2500 and 1500 Purkinje cells transduced for rAAV5 or rFIV-based vectors, respectively. The vectors also transduced stellate, basket and Golgi neurons, with occasional transduction of granule cells and deep cerebellar nuclei. rAAV5 also spread outside the cerebellum to the inferior colliculus and ventricular epithelium, while rFIV demonstrated the ability to undergo retrograde transport to the physically close lateral vestibular nuclei. Thus, AAV5 and FIV-based vectors show promise for targeting neurons affected in the hereditary spinocerebellar ataxias. These vectors could be important tools for unraveling the pathophysiology of these disorders, or in testing factors which may promote neuronal survival.

[Diagnosis of malnutrition in the elderly by dual energy absorptiometry]

OBJECTIVES

Denutrition is a frequent condition in elderly persons and may have major consequences. A noninvasive investigation, whole body dual energy X-ray absorptiometry, should allow, by direct measurement of body composition, early and reliable diagnosis of denutrition. This study was conducted to elaborate a diagnostic tool using this exam and to test its validity.

PATIENTS AND METHODS

A global index of denutrition was proposed combining anthropometric, biological criteria, and the Mini Nutritional Assessment scale. Two agreement analyses were made between classical diagnostic criteria of nutritional status and body fat and fat free mass assessed by anthropometry and absorptiometry. An association between nutritional status and body absorptiometric composition were studied with univariate analysis followed by a multivariate logistic regression model. This model allowed an elaboration of a nutritional absorptiometric index (NAI).

RESULTS

One hundred one elderly subjects were included. Twenty-three were considered to be in a state of denutrition. Agreement was poor between anthropometric and biological diagnostic criteria of denutrition. It was good between the different masses assess by anthropometry and absorptiometry. Subjects in a state of denutrition had significantly lower body fat and lower fat free mass. The fat free mass index (fat free mass divided by the square height) and body fat were entered into a logistic model and composed the NAI, which showed good diagnostic validity in terms of specificity and sensitivity.

DISCUSSION

Absorptiometry appears to be a simple reliable diagnostic tool for assessing denutrition in elderly persons in routine practice. Further studies are required and should lead to a confirmation of the interest of these absorptiometric indexes.

Factors predicting the long-term success of maintenance cyclosporine monotherapy after kidney transplantation

BACKGROUND

The theoretical aim of maintenance cyclosporine monotherapy (mCsA) after kidney transplantation is to reduce the incidence of the metabolic complications of corticosteroids and to minimize the adverse effects of excessive long-term immunosuppression. This study was performed in low-immunological-risk cadaveric kidney transplant recipients to evaluate the risks and benefits of mCsA and the long-term graft survival, and to determine the factors predicting success of this policy.

METHODS

The multicenter retrospective study was conducted in 329 Caucasian patients receiving mCsA out of 728 first cadaveric kidney transplant recipients. The inclusion criteria were: HLA antibodies < or =25%, serum creatinine <200 micromol/L, and no rejection or only one rejection episode. At the end of the study, we compared the group of patients successfully treated with mCsA (successful group) with those requiring additional immunosuppressive agents (unsuccessful mCsA group).

RESULTS

Overall patient and graft survival rates for the 728 first cadaveric graft were 92% and 64%, respectively, at 8 years. Out of 329 patients enrolled in mCsA, 240 were maintained on this treatment and 89 were withdrawn (3 deaths, 18 graft losses, 68 functional grafts). The 8-year graft survival in the 329 enrolled mCsA patients was 84%, 95% in the successful mCsA group, and 70% in the unsuccessful mCsA group. Multivariate analysis showed that the factors predicting success of mCsA were: donor age <40 years (P = 0.001), serum creatinine at mCsA initiation <125 micromol/L (P = 0.02), no rejection episode before mCsA initiation (P = 0.005), and glomerulopathy as the primary renal disease (P = 0.001).

CONCLUSION

Numerous kidney transplant recipients with a low immunological risk and good and stable renal function may benefit from discontinuation of prednisone and azathioprine in order to reduce the complications related to these drugs. This therapeutic approach had no adverse impact on the overall long-term graft survival for "low risk" and successful patients.

Effects of financial incentives on medical practice: results from a systematic review of the literature and methodological issues

OBJECTIVE

To identify all financial incentives that had been proposed, described, or used regardless of their initial objective and, when possible, to assess the results of these incentives on costs, process or outcomes of care.

MATERIAL AND METHODS

Systematic review of the literature. Databases searched were: Medline, Embase, Health Planning and Administration, Pascal, International Pharmaceutical Abstracts and the Cochrane Library. Search terms were: health professionals and tape of practice, type of incentive, methodology, languages English or French, January 1993 to May 1999.

RESULTS

Financial incentives concerned the modalities of physician payment and financing of the health care system. Confounding factors included: age of the doctor, training, speciality, place and type of medical practice, previous sanctions for over-prescribing, type and severity of disease, type of insurance. Risks of financial incentives were: limited access to certain types of care, lack of continuity of care, conflict of interests between the physician and the patient. Any form of fund-holding or capitation decreased the total volume of prescriptions by 0-24%, and hospital days by up to 80% compared with fee-for-service. Annual cap on doctors' incomes resulted in referrals to colleagues when target income is reached.

DISCUSSION

Financial incentives can be used to reduce the use of health care resources, improve compliance with practice guidelines or achieve a general health target. It may be effective to use incentives in combination depending on the target set for a given health care programme.

Health promotion in France. Toward a new way of giving medical care

Health promotion is not a concept often encountered in France, especially in university teaching hospitals. In fact, the spontaneous orientation of healthcare services tends to emphasize high-technology care, rather than preventive care. This article describes the main characteristics of the French healthcare system, some new elements of its health policy, and a specific experiment of health promotion in a new geriatric hospital.

[Cytomegalovirus infection, a risk factor for acute graft rejection in renal transplant recipients. A case-controlled study]

OBJECTIVES

We studied the relationship between cytomegalovirus infection and episodes of acute rejection after infection in renal graft recipients at the Reims University Hospital from 1989 to 1995.

PATIENTS AND METHODS

Two exposed versus nonexposed analyses were conducted, one (series 1) for CMV infection and the other (series 2) for CMV disease. For each analysis, exposed recipients were matched with nonexposed recipients for date of graft (+/- 6 months). Risk of acute rejection was assessed with univariate analysis then with multivariate analysis using logistic regression.

RESULTS

Among the 192 graft recipients included, 64 developed CMV infection, 77 had an infection (series 1) and 51 had CMV disease (series 2). In series 1, only failure of renal graft was a significant risk factor of acute rejection (OR = 10.4; 95% Cl 1.9-56.3). CMV infection was not a significant risk factor (OR = 1.06; 95% Cl 0.2-5.6). Conversely, in series 2, there was a 6-fold increase in the risk of acute rejection in recipients who developed CMV disease (OR = 5.98; 95% Cl 1.21-29.4).

CONCLUSION

The fact that CMV disease and not CMV infection is a risk factor of acute rejection in renal transplant recipients is an argument for implicating a general inflammatory reaction characteristic of CMV disease in the pathogenesis of acute rejection. This finding favors preventive treatment of CMV infection.

Increased gene transfer into human CD34+ progenitor cells using retroviral vectors produced by a canine packaging cell line

Using retroviral supernatants derived from the amphotropic murine packaging cell line PA317 and the amphotropic canine packaging cell line (DA), cord blood and mobilized peripheral blood CD34+ cells were transduced with the vector LN (neomycin resistance) and the vector L-TR/TAT neo (neomycin resistance in conjunction with a double-hammerhead ribozyme conferring anti-HIV activity). Different multiplicities of infection (MOI) were applied in the setup according to vector titrations on NIH-3T3 cells. PA317-based supernatants were tested at MOI of 10 and 30. Purified concentrated DA-derived vector preparations were tested at MOI of 10, 30, 100, and 300. Immediately after transduction, CD34+ cells were plated into colony assays in the presence and absence of G418 to evaluate the amount of gene transfer and potential toxic effects of the vectors on colony growth. The remaining cells were subjected to G418 selection in liquid culture for 12 days and subsequently challenged with HIV-1JR-FL to test for efficacy of the anti-HIV gene in macrophages derived from transduced CD34+ cells. Transduction by the PA317-packaged vectors was maximal at the lowest MOI used and did not increase with increasing MOI. In contrast, transduction by the DA-packaged vectors could be progressively increased using increased MOI. The net transduction efficiency per unit of reverse transcriptase activity in the DA vector preparations was 8.7-fold higher than in the PA317 vector supernatants. HIV-1 challenge of the cells transduced by the ribozyme vector derived from the PA317 packaging cells resulted in a 1.5 log inhibition of p24 output compared with the control cells containing neomycin resistance only. A 2.5 log inhibition of p24 output could be observed in the cell population transduced with DA-packaged vector supernatants. Compared with retroviral supernatants from PA317 packaging cell lines, DA packaging line-derived vector preparations demonstrated higher transduction efficiency into CD34+ cells, particularly at higher MOI, and increased efficacy of the transferred anti-HIV gene when challenged with HIV-1JR-FL. The increase in transduction efficiency may be due to a higher ratio of intact vs. defective vector particles in the DA-derived vector preparations.

Generation of a systemic antitumor response with regional intratumoral injections of interferon gamma retroviral vector

The generation of a lasting systemic immune response is a primary goal for cancer immunotherapy. Here we examine the ability of high-titer IFN-gamma retroviral vector injected into an accessible tumor to generate significant antitumor responses at a distal untreated site. CT26 or B16F10 murine tumors were inoculated subcutaneously to form solid tumors in BALB/c or C57BL/6 mice. Seven to 10 days postinoculation, high-titer IFN-gamma retroviral vector was directly injected into the subcutaneous tumor nodule, and optimal dose and course of therapy were determined. As a model for disseminated disease, mice were inoculated intravenously with CT26 cells to form pulmonary lesions, at the same time as the subcutaneous injections. Regression of subcutaneous tumor correlated with a systemic response at the distal lung metastases in the IFN-gamma-treated group (p < 0.0005). Splenocytes from mice with completely regressed tumors had a twofold increase in percent specific cytotoxicity in a standard CTL assay as compared with nonresponding mice. CD8+ T cells were shown to be essential for the regional and systemic antitumor response, as determined by in vivo cell depletion experiments. These data demonstrate that IFN-gamma retroviral vector gene therapy delivered intralesionally can generate significant inhibition of pulmonary tumor formation distal to the treatment site. The data from these preclinical studies suggest the potential clinical value of retroviral vector-mediated cytokine gene therapy for systemic cancer.

Outcome of erosive/ulcerative reflux oesophagitis in 181 consecutive patients 5 years after diagnosis

BACKGROUND

Controversy exists as to whether oesophagitis worsens over the long-run and long-term follow-up studies of homogeneous series are scarce.

AIMS

This study assessed the level of symptoms and the proportions of patients who underwent anti reflux surgery or were on antisecretory therapy.

PATIENTS AND METHODS

Files from 286 patients with a first time diagnosis were retrieved. Outcome data was obtained over the phone from the general practitioners and from the patients.

RESULTS

Seventy-five patients had died (26.2%), 2 of whom from anti reflux surgery, and 30 (14.2%) could not be contacted. Of the 181 patients contacted, 18 (9.9%) had undergone anti reflux surgery. Of the 163 remaining patients, 57.7% were no longer on medication (group 1), 31.9% were using antacids, alginate or cisapride (group 2) and 10.4% were on antisecretory therapy (group 3). High initial grades of oesophagitis and older age were linked to antisecretory drug consumption. There were no new cases of haemorrhage or stricture.

CONCLUSIONS

Patients in this study showed a low rate of symptomatic relapse and of antisecretory drug requirements and no complications despite having had oesophageal breaks.

Effect of chlorambucil on bone mineral density in the course of chronic lymphoid leukemia

The purpose of this work was to study the effects of chronic lymphoid leukemia (CLL) and its treatments on bone mineral density (BMD). Lumbar and femoral BMD was measured by X-ray absorptiometry in 50 (32 M, 18 F, median age 65, range age: 47-87 yr) CLL patients. In order to gauge the respective effects of CLL and corticoids on bone mass, 31 CLL patients under treatment were compared with 31 controls on cortisone. Nineteen untreated patients with CLL were compared with controls devoid of osteopenia risk factor. There was no significant difference regarding lumbar and femoral BMD between the untreated patients with CLL and the healthy controls. An increase in lumbar and femoral BMD was noted in the treated CLL group compared with the controls on cortisone (lum BMD: 1.018 vs. 0.861 g/cm2, p=6.10(-4); fem BMD: 0.773 vs. 0.699 g/cm2, p=0.037). This increase was observed only in patients who had received chlorambucil (lum BMD: 1.066 vs. 0.861 g/cm2, p=0.10(-4); fem BMD: 0.806 vs. 0.699 g/cm2, p=4.10(-3)), whereas there was no difference between the CLL patients treated without chlorambucil and the controls on cortisone. Multiple linear regression analysis confirmed the marked effect of chlorambucil (r=0.3715, p<10(-3)) on BMD increase in the course of CLL.

Effects of ANF infusion on the renal responses to lower-body negative pressure in humans

To investigate the role of atrial natriuretic factor (ANF) in renal responses to a decrease in central blood volume, we examined the effects of ANF infusion on renal function and hormones during prolonged lower-body negative pressure (LBNP). Ten healthy volunteers participated in two experimental sequences, each comprising a 120-min baseline period followed by the application of -20 mm Hg LBNP for 90 min. During one of the two sequences, ANF was infused throughout LBNP application at the constant rate of 2.5 ng/kg/min. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured by using inulin and p-aminohippuric acid clearance techniques. LBNP induced a significant decrease in ERPF (534 +/- 28 to 457 +/- 26 ml/min; p < 0.05), GFR (120 +/- 2.5 to 112 +/- 2.5 ml/min; p < or = 0.01), in urine excretion (12 +/- 0.9 to 5.6 +/- 0.5 ml/min; p < 0.001), in sodium excretion (0.36 +/- 0.03 to 0.30 +/- 0.02 mmol/min; p < 0.05), and in plasma ANF (19 +/- 3 to 11 +/- 2 pg/ml; p = 0.001) concomitant with an increase in plasma renin activity (PRA; 0.48 +/- 0.09 to 0.87 +/- 0.16 ng/ml/h; p = 0.01) and of forearm vascular resistance (FVR; p < 0.05). The combination of ANF infusion with LBNP led to a slight increase in plasma ANF from baseline (from 20 +/- 2 to 28 +/- 3 pg/ml; p < 0.05). Compared with values obtained during LBNP with saline vehicle infusion, values obtained during LBNP with ANF infusion were similar for ERPF (463 +/- 23 vs. 457 +/- 26 ml/min), for GFR (111 +/- 2 vs. 112 +/- 2 ml/min), and for urine excretion (7 +/- 0.6 vs. 5.6 +/- 0.5 ml/min; p = 0.07), but greater for fractional excretion of sodium (2.38 +/- 0.25% vs. 1.91 +/- 0.11%; p < 0.05) and FVR (p < 0.05), and smaller for PRA (0.49 +/- 0.1 vs. 0.87 +/- 0.16 ng/ml/h; p < 0.01). These data show that ANF infusion attenuates the antinatriuretic effect of low-level LBNP and its PRA-increasing effects without altering renal hemodynamic responses to LBNP, although there is a decrease in the LBNP-induced forearm vasoconstriction. These results were obtained with plasma ANF levels slightly higher than those in baseline. They support the hypothesis that a decrease in ANF secretion might contribute to the antinatriuretic effect of LBNP.

A chimeric Ty3/Moloney murine leukemia virus integrase protein is active in vivo

This report describes the results of experiments to determine whether chimeras between a retrovirus and portions of Ty3 are active in vivo. A chimera between Ty3 and a Neo(r)-marked Moloney murine leukemia virus (M-MuLV) was constructed. The C-terminal domain of M-MuLV integrase (IN) was replaced with the C-terminal domain of Ty3 IN. The chimeric retroviruses were expressed from an amphotrophic envelope packaging cell line. The virus generated was used to infect the human fibrosarcoma cell line HT1080, and cells in which integration had occurred were selected by G418 resistance. Three independently integrated viruses were rescued. In each case, the C-terminal Ty3 IN sequences were maintained and short direct repeats of the genomic DNA flanked the integration site. Sequence analysis of the genomic DNA flanking the insertion did not identify a tRNA gene; therefore, these integration events did not have Ty3 position specificity. This study showed that IN sequences from the yeast retrovirus-like element Ty3 can substitute for M-MuLV IN sequences in the C-terminal domain and contribute to IN function in vivo. It is also one of the first in vivo demonstrations of activity of a retrovirus encoding an integrase chimera. Studies of chimeras between IN species with distinctive integration patterns should complement previous work by expanding our understanding of the roles of nonconserved domains.

Retroviral gene transfer into cord blood stem/progenitor cells using purified vector stocks

Cord blood (CB) progenitor/stem cells (P/SC) are ideal targets for early gene therapy in individuals prenatally diagnosed with genetic disorders. Most retroviral transduction protocols were developed using adult peripheral blood stem cells (PBSC) and bone marrow (BM). Less is known about retroviral transduction of CB P/SC. We examined how timing, multiplicity of infection (MOI), and polycations in the transduction media affect transduction efficiency. Rates of transduction were determined in recently isolated CD34+ enriched CB cells and in colonies derived after various times in liquid cultures (LC). CB mononuclear cells (MNC) were separated by ficoll-hypaque centrifugation and enriched for CD34+ cells. Purity was assessed by flow cytometry. Transduction were performed with clinical-grade retroviral stocks at MOIs of 1-20. Transduction was performed with fetal bovine serum (FBS) or autologous plasma, IL-3, GM-CSF, IL-6, and SCF. The retroviral vector contained LacZ and neomycin resistance (neo) reporter genes. Transduction was determined by X-gal stain and by PCR amplification of the reporter genes. No drug selection was used. Twenty-five experiments were done. CB volumes ranged from 35-150 ml. MNC and CD34+ cell counts ranges were: 0.14-840 x 10(6) and 0.1-4.2 x 10(6), respectively. Transduction efficiency in liquid cultures ranged from 4-63%. Higher rates were seen using MOI > or = 10, 2 microg/ml polybrene, and 10% autologous CB plasma. In colonies, transduction rates were 63 to 72% by PCR and 32% by X-gal staining. In LTC-IC derived colonies, transduction was 7% by PCR. Short incubations of CD34+ CB cells with purified retroviral stocks, polybrene, and autologous sera result in high transduction rates of committed progenitors and moderately low efficiencies of transduction of LTC-IC in the absence of drug selection.

Life events and disability in rheumatoid arthritis: a European cohort

The objective was to study the relationship between life events (LE) and the clinical status of patients suffering from recently diagnosed rheumatoid arthritis (RA) in a 2 yr follow-up. As part of a multicentre European cohort study, 370 French and Dutch patients were questioned three times at 1 yr intervals about LE which had occurred in the previous year. Three criteria were used to quantify the degree of disease activity (Ritchie's index), the level of functional disability [Health Assessment Questionnaire (HAQ)] and perceived health [Overall Evaluation of Health (OEH)]. Total LE and desirable LE showed a weak negative correlation with the HAQ scores. On the other hand, death-related LE did not seem to modify patient status. The higher the number of health-associated LE, the greater the deterioration in HAQ and OEH scores. The results indicate that LE do not affect the course of early RA in a spectacular manner.

A Phase I clinical trial of immunotherapy with interferon-gamma gene-modified autologous melanoma cells: monitoring the humoral immune response

BACKGROUND

Tumor cells transduced with cytokine genes provide immunogenic vaccines for cancer immunotherapy.

METHODS

A Phase I clinical trial was conducted for the specific active immunization of melanoma patients with interferon-gamma (IFN-gamma) gene-modified autologous melanoma tumor cells. Short term melanoma cultures were transduced retrovirally with the gene for human IFN-gamma. The genetically modified melanoma cells secreted biologically active IFN-gamma and showed enhanced expression of major histocompatibility complex class I and class II surface antigens. These cells were inactivated by irradiation (50 gray) and were cryopreserved for the vaccine. Twenty melanoma patients were enrolled in this clinical trial. The immunizations were administered in escalating doses once every 2 weeks for 3 months. The first and second injections consisted of 2 million cells, followed by 6 million for the third and fourth injections, and then 18 million for the fifth and sixth injections. The humoral immune responses of the patients were assessed by enzyme-linked immunoadsorbent assay, radioimmunoassay, and radioimmunoprecipitation.

RESULTS

Thirteen of the 20 patients completed the immunization protocol. Eight of these 13 patients showed a humoral immunoglobulin (Ig)G response against autologous and allogeneic melanoma cells. The other five patients either had no detectable antimelanoma antibodies or showed a weak IgG response that did not rise significantly above the preimmune level. All the sera contained low or undetectable levels of antimelanoma IgM antibodies. The IgG response increased progressively in titer during the course of immunization. The positive sera showed preferentially strong binding to melanoma cell lines and some cross-reactivity to nonmelanoma tumors. A 75-80 kD antigen on melanoma cells was immunoprecipitated by postimmune sera of 3 of the responding patients. Preimmune sera from these three patients and sera from other patients immunized with a standard nontransduced melanoma cell vaccine failed to precipitate this antigen. Two patients with significant increases in serum IgG had clinical tumor regression, and two additional patients with low serum IgG response had transient shrinkage of nodular disease during therapy.

CONCLUSIONS

These data suggest that gene therapy with IFN-gamma-transduced melanoma cells is safe and worthy of further investigation in patients with less advanced stage malignant melanoma. The ability to monitor changes in the humoral responses of the immunized patients has been demonstrated.

Effect of Low Glacial Atmospheric CO2 on Tropical African Montane Vegetation

Estimates of glacial-interglacial climate change in tropical Africa have varied widely. Results from a process-based vegetation model show how montane vegetation in East Africa shifts with changes in both carbon dioxide concentration and climate. For the last glacial maximum, the change in atmospheric carbon dioxide concentration alone could explain the observed replacement of tropical montane forest by a scrub biome. This result implies that estimates of the last glacial maximum tropical cooling based on tree- line shifts must be revised.

[Transthoracic echocardiography and diagnosis of acute pulmonary embolism. Change in the diagnostic valve with respect to thresholds of classification]

The diagnostic value of transthoracic echocardiography in acute pulmonary embolism is not well established. Although many parameters are abnormal, the thresholds used vary according to the authors, limiting the contribution of the investigation to the diagnosis. In a prospective study of 70 patients with suspected acute pulmonary embolism without previous cardio-respiratory disease, the authors tried to determine the diagnostic thresholds using discriminating linear analysis and ROC curves. Parameters easily recorded in an emergency were analysed: end diastolic ventricular dimensions, ratio of these diameters and maximal velocity of tricuspid regurgitant flow. Thirty-one patients had pulmonary embolism quantified by the Miller index (average: 16 +/- 7, range 2 to 28). Measurements of left ventricular dimension were disappointing (sensitivity: 0.52, specificity: 0.73 for a threshold value of 45 mm). The right ventricular dimension was a better predictive parameter (sensitivity: 0.70, specificity: 0.86 for a threshold value of 25 mm). However, the ratio of right to left ventricular dimension had a better diagnostic value (sensitivity: 0.85, specificity: 0.78 for a threshold value of 0.5). The best diagnostic parameter was the maximal velocity of tricuspid regurgitation (sensitivity: 0.93, specificity: 0.82 for a threshold value of 2.5 m/s). The authors conclude that the maximal velocity of tricuspid regurgitation with a threshold of 2.5 m/s and the ratio of the ventricular dimensions with a threshold value of 0.5 are valuable diagnostic indicators for acute pulmonary embolism.

Eradication of melanoma pulmonary metastases by immunotherapy with tumor cells engineered to secrete interleukin-2 or gamma interferon

This study was undertaken to investigate the effectiveness of interleukin-2 (IL-2) and gamma interferon (gammaIFN)-modified B16 melanoma cells in the immunotherapy of established melanoma pulmonary metastases. The genes for IL-2 and gammaIFN were introduced retrovirally into B16 melanoma cells. Transduction with the gammaIFN, but not the IL-2, gene caused significant increases in the expression of major histocompatibility complex (MHC) antigens on B16-gammaIFN cells. The in vivo tumor-forming capacity of both IL-2- and gammaIFN-transduced B16 cells was drastically reduced when the cells were inoculated subcutaneously (SC) in syngeneic C57BL/6 mice. After intravenous (IV) inoculation, most of the B16-gammaIFN cells were rejected, but B16-IL-2 cells were relatively tumorigenic and formed pulmonary metastases. C57BL/6 mice bearing 4-day established parental B16 lung metastases were treated with B16 parental (B16P) unmodified cells, IL-2- or gammaIFN-modified B16 cells, or a combination of both transduced cells. Treatment consisted of a weekly intraperitoneal (IP) injection of one million irradiated (10,000 rad) tumor cells alone or in combination with exogenous IL-2 for a total of three to four injections. Immunotherapy with B16 parental or B16-IL-2 secreting cells caused a moderate reduction in the number of lung metastases. However, mice treated with gammaIFN-secreting B16 cells showed a significant reduction or complete elimination of lung metastases. There was no additive effect for combining both IL-2- and gammaIFN-modified tumor cells in the immunotherapy. Exogenous IL-2 (50,000-100,000 U/day for 3 days) caused a significant enhancement of the immunotherapeutic benefit of the vaccines. Moreover, mice treated with gammaIFN-modified B16 cells survived longer than the other groups. Twenty-five percent of these mice were tumor free and remained alive for an observation period of 4 months. The in vitro cytolytic activity of splenocytes in chromium release assays did not correlate in every case with the in vivo antitumor effect of the treatment. Our findings have implications for the use of cytokine-modified cells for immunotherapy and for evaluating the therapeutic benefit of this novel treatment.

In vivo microdialysis in the rat: low cost and low labor construction of a small diameter, removable, concentric-style microdialysis probe system

A method for construction of a serviceable and low cost intracerebral microdialysis system is presented. The system includes a probe and its supporting components. The probe is of the concentric design. The supporting components are an implantable guide cannula, a tether, and a swivel. After minimal training, workers can make many probes of consistent performance characteristics in a short time. Because all of the parts are commercially produced, users may obtain custom-made components which are finished with factory precision and accuracy. The user may readily vary probe characteristics such as depth of implant and size of active portion, so that different types of dialysis may be performed in different brain regions. The available choices in tether and swivel configurations make this microdialysis system readily adaptable to diverse testing environments. Excluding labor and startup costs, the costs, the cost per probe is approximately $11.00 (US). Taken together, the system provides a flexible, low cost means for performing in vivo microdialysis in freely moving rats.

Effectiveness and prognostic factors of success in 12 smoking cessation clinics in the hospitals of Assistance publique-Hôpitaux de Paris

We evaluated whether the location of a smoking cessation clinic in a hospital enhances the success rate compared to that found in the literature, regardless of the type of treatment. We assessed the results and identified prognostic factors of success in 12 smoking cessation clinics situated in 12 hospitals of the Assistance publique-Hôpitaux de Paris (AP-HP). The clinics were included in the study after a call for participation. The response rate was 60%. The study design was prospective, multicentric and descriptive. The study lasted 9 months. Follow-up took place 3 and 6 months after the first visit. The definition of success was self-reported total abstinence from cigarette smoking during the month preceding the 6-month follow-up. Success rate was 27%, failures were 66%, and 7% were lost to follow-up. Prognostic factors of success were not related to the hospital setting. We conclude that for a number of structural reasons that we explain, according to this study, the location of smoking cessation clinics in hospitals does not enhance their success rate compared to that found in the literature.

Use of transthoracic Doppler echocardiography combined with clinical and electrocardiographic data to predict acute pulmonary embolism

Transthoracic echocardiography and continuous wave Doppler were prospectively performed in 132 out-patients with suspicion of pulmonary embolism, and who had no previous history of severe cardiac or pulmonary disease. Bedside echocardiography determined diagnosis other than pulmonary embolism in 55 patients. Further study was completed in 70 patients; pulmonary embolism was found in 31 and excluded in 39. Significant differences were found as regards right ventricular diameter (27 +/- 8 vs 22 +/- 5 mm, P < 0.001), left ventricular diameter (41 +/- 9 vs 49 +/- 7 mm, P < 0.001), right over left ventricular diameter ratio (0.67 +/- 0.23 vs 0.43 +/- 0.15, P < 0.0001), tricuspid regurgitant flow peak velocity (2.9 +/- 0.4 vs 2.4 +/- 0.7 m.s-1, P < 0.0001), and abnormal septum motion (12 vs 4, P < 0.01). Multivariate analysis of echocardiographic data included a tricuspid regurgitant flow peak velocity greater than 2.5 m.s-1 and a right over left ventricular diameter ratio greater than 0.5 in a logistic model (sensitivity 93%, specificity 81%). The combination of echocardiographic and non-echocardiographic data included the two previous echocardiographic variables, together with signs of deep vein thrombosis, a deep S wave in lead D1, and a Q wave in lead D3 on the electrocardiogram in a logistic model (sensitivity 96%, specificity 83%). It can be concluded that emergency echocardiography, alone or combined with clinical examination and electrocardiogram, satisfactorily predicts acute pulmonary embolism.

Interferon gamma (IFNgamma) gene transfer of an EMT6 tumor that is poorly responsive to IFNgamma stimulation: increase in tumor immunogenicity is accompanied by induction of a mouse class II transactivator and class II MHC

Abstract Interferon gamma (IFNgamma) is an important cytokine with immunomodulatory properties that include activation of immune cells and induction of class I and class II major histocompatibility complex antigens. In this study a retroviral vector was used to introduce the IFNgamma gene into EMT6 tumor cells to assess the effect of IFNgamma gene expression on tumor immunogenicity. Transfectants were selected in G418-containing tissue-culture medium and were determined to express the inserted IFNgamma gene by reverse transcriptase/polymerase chain reaction. Flow-cytometric analysis revealed that parental unmodified EMT6 cells constitutively expressed only class I MHC and were poorly responsive to exogenous IFNgamma stimulation, whereas class II MHC was induced in IFNgamma-transfected cells. The induction of class II MHC in IFNgamma-transfected cells correlated with the expression of a mouse class II transactivator gene that was dormant in unmodified or mock-transfected cells. In addition, IFNgamma-gene-transfected tumor cells were found to secrete up to 17 ng IFN (equivalent to 75 units/10(6) cells) by enzyme-linked immunosorbent assay (ELISA). Whereas parental EMT6 cells grew unchecked, the growth of genetically modified tumor cells was significantly inhibited in immunocompetent mice. Rechallenge of animals that rejected an IFNgamma-transfected EMT6 clone (EMT6-B17) with parental EMT6 cells resulted in tumor rejection, suggesting that IFNgamma-transfected EMT6 cells were able to induce long-term immunity. Mixing experiments using gene-transfected and unmodified tumor cells demonstrated that 10% of IFNgamma-transfected cells in the population was sufficient to protect mice against subsequent challenge with tumorigenic EMT6 cells. These studies demonstrate that the immunogenicity of tumor cells that are poorly responsive to exogenous IFNgamma can be enhanced by inserting and expressing the IFNgamma transgene. These findings also suggest a role for class II MHC in reducing tumorigenicity of the EMT6 tumor and inducing long-term tumor immunity.