A risk model for non-small cell lung cancer using clinicopathological variables, angiogenesis and oncoprotein expression

BACKGROUND

The aim of this study was to investigate new prognostic factors, by using a prognostic model, that could help to identify the patient group with the greatest probability of death.

PATIENTS AND METHODS

First, the clinicopathological variables were analyzed. Second, microvessels were immunohistochemically (IHC) stained with factor VIII-related antibody and then counted in the most intense vascularization area or hotspot, using an automatic image analyzer. In addition, biological angiogenesis-related factors such as vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase expression (iNOS) were also studied. Finally, we evaluated the IHC expression of p53 and p21WAF1 tumor supressor proteins.

RESULTS

The significant independent predictors were: tumor size (p=0.0063), angiogenesis (p=0.0271) and p21WAF1 (p=0.0478). Thus, the most important factor was tumor size 2.7462 [95% CI=1.3307-5.6673]. Finally, these variables were included in a risk model, in order to identify the group with the highest associated probability of death.

CONCLUSION

The analysis of several prognostic factors could establish a more accurate patient risk profile.

[Stage I nonsmall cell lung cancer up to 3 cm in diameter. Prognostic factors]

OBJECTIVE

To assess the prognostic value of a series of clinicopathological variables in stage I nonsmall cell lung cancer, for tumors up to 3 cm in diameter.

PATIENTS AND METHOD

The study included 271 patients. Survival was analyzed with the Kaplan-Meier method. The Cox model was used for multivariate analysis.

RESULTS

Five- and ten-year survival were 78.63% and 67.59%, respectively. Survival did not significantly depend on sex, age, extent of resection, histology, visceral pleural invasion, level of bronchial invasion or T1 versus T2. The decade in which resection was performed did affect survival (P=.0037). Five-year survival was 58% for operations between 1970 and 1980, 77% for operations between 1981 and 1990, and 84% for operations between 1991 and 2000. Tumor size also affected survival (P=.0046), which was 86% for patients with tumors of less than or equal to 2 cm in diameter and 73% for those with tumors of more than 2 cm in diameter. In the multivariate analysis both variables entered into regression, remaining predictive of survival.

CONCLUSION

We found evidence for a prognostic stage migration (Will Rogers phenomenon) according to the decade in which resection was performed and that tumor size affected survival in our population. Finally, the current system of TNM staging fails in conforming groups of patients with a homogenous prognosis.

Pencil-beam versus fan-beam dual-energy X-ray absorptiometry comparisons across four systems: appendicular lean soft tissue

Dual-energy X-ray absorptiometry (DXA) provides an important opportunity for estimating total body skeletal muscle (SM) mass from DXA-measured appendicular lean soft tissue (ALST). A DXA SM prediction model was developed with magnetic resonance imaging as the reference and ALST (i. e., sum of arm plus leg lean soft tissue) as a main predictor variable. In the present study we examined whether ALST estimates are comparable across systems (i. e., penciland fan-beam) and manufacturers. Pencil-beam systems (Lunar DPX and DPX-L) are usually considered more accurate but slower than fan-beam systems (Lunar Prodigy and Hologic Delphi A). In this study we compared ALST estimates in 35 healthy adults across these four systems. The methods gave similar group mean (+/-SD) values and were highly intercorrelated. There was no significant bias detected across the four systems. ALST estimates from the evaluated DXA systems are comparable and thus appear interchangeable as methods for quantifying total body SM in vivo.

[Emergency lung transplantation]

INTRODUCTION

Lung donors are scarce and lung transplantation resources limited, leading to a need to look at transplants in terms of efficiency. Because emergency transplants (C-0) are assumed to yield poor results, most countries do not perform them on a regular basis. Spain, however does accept the concept of emergency lung transplantation for patients who are on waiting lists. We assess outcome for our patients who have received scheduled and emergency transplants.

MATERIAL AND METHOD

The survival of patients receiving lung transplants in our service from 1992 through 2001 was studied using, Kaplan-Meier, Cox regression and chi-squared statistical analyses. We compared outcome and perioperative mortality (over 30 days) for scheduled versus C-0 procedures, analyzing the influence of certain variables (age, sex, emergency status, type of transplant, mechanical ventilation and use of extracorporeal membrane oxygenation).

RESULTS

Eleven of 183 lung transplants were C-0 and 172 were scheduled. Forty-one were single-lung and 142 were double-lung transplants. Perioperative mortality was 36.4% for emergency procedures and 8.7% for scheduled procedures (p = 0.0035). Survival was significantly better for scheduled patients than for C-0 patients (p = 0.0032), although outcome was similar when perioperative mortality was not taken into account (58.16% vs. 57.14% at 5 years for scheduled and C-0 patients, respectively).

CONCLUSIONS

Long-term survival after lung transplantation shows that the procedure is effective and efficient in C-0 patients, in spite of perioperative risk, provided the patient has been adequately monitored.

[Right primary iliac artery rupture during transurethral resection of bladder tumor]

Injury to a large-caliber artery transurethral resection of a bladder tumor is a rare but serious complication. It is important that an anesthesiologist be able to detect such an injury, in order to include it among the many differential etiological diagnoses for shock. A 75-years-old man reported hematuria. An ultrasound image of the bladder showed many neoformations consistent with a diagnosis of multiple bladder neoplasms, and transurethral endoscopy was performed under subarachnoid anesthesia. Acute hypotension, bradycardia and shock developed 30 minutes into the procedure. The diagnosis was hypovolemic shock due to acute intraoperative hemorrhage, and exploratory laparotomy revealed an opening in the common iliac artery. The rupture was sutured. In spite of administration of crystalloids, colloids, blood products and vasoactive agents, a second operation was required due to hemodynamic instability. The patient died in the intensive care unit.

Survival and risk model for stage IB non-small cell lung cancer

BACKGROUND

The aim of this work is to estimate the prognostic value of a set of clinical-pathological factors in patients resected for non-small cell lung cancer (NSCLC) and classified as stage IB, in order to create a prognostic model for establishing risk groups, and to validate that model.

METHODS

Among 637 patients resected and classified as stage IB, we analyzed sex, age, symptoms, location, type of resection, cell type, histology, and tumor size. The Kaplan-Meier method was used to estimate the survival. The results were compared using the log-rank test. All the significant variables from this univariable method were then included in a multivariable method of estimation of the proportional risk for survival data developed by Cox, using the variables selected, a regression model was developed for accurately predicting survival. To validate the predictive capability of the regression model, we randomly divided our patients into training and test subsets, containing 322 and 315 cases, respectively.

RESULTS

The overall 5-year survival rate of the series was 60%. The cell type, the squamous or non-squamous and the tumor size showed a significant influence on survival in the univariable analysis, while, according to the Cox model, only the tumor size and the squamous or non-squamous type entered into regression. Hazard rates were calculated for each patient. The mean risk was 0.87 +/- 0.25 (range 30-1.94). The series was divided into three risk groups (low, intermediate, and high risk) according to the fitted hazard rates, using cut-off points (one standard deviation from the mean). The 5-year survival rates were 85, 59, and 44%, respectively. To validate the model, we repeated the analysis for training and test subsets. Only the tumor size had a significant influence on survival in the univariable analysis. Using the Cox model, also the tumor size entered into regression. The mean risk was 0.79 +/- 0.29 (range 0.09-2.12). Cut-off points were 0.50 and 1.08 for the low, intermediate, and high-risk groups. The 5-year survival rates were 83, 58, and 40%, respectively. We validated the regression model obtained in the training subset by demonstrating its capacity in identifying risk groups in the test subset. The 5-year survival rates were 83, 61, and 49.5% for the low, intermediate, and high-risk groups, respectively (P = 0.0104).

CONCLUSIONS

Stage IB does not succeed in configuring a group of patients with a homogeneous prognosis, as there is a wide variability in a 5-year survival. The estimation of prognosis derived from a multivariable analysis can obviate the limitations of the actual staging system for NSCLC.

[Single-lung transplant and primary graft failure]

OBJECTIVE

To quantify primary graft failure (PGF) and its impact on perioperative and early mortality in single-lung transplant (SLT).

METHOD

We analyzed 35 SLT procedures performed using similar techniques. PGF was defined as a PaO2/FiO2 coefficient lower than 200 mmHg during the first 72 hours or ventilation assistance lasting longer than 5 days attributable to primary lung dysfunction. We defined perioperative mortality as occurring within 30 days of surgery and early mortality within 90 days.

RESULTS

Twenty-five men and 10 women received lungs, 22 for pulmonary fibrosis and 13 for emphysema; the mean age was 53.26 10.77 years. Twenty right SLTs were performed and 15 left SLTs. Twenty-nine donors were men and 6 were women, with a mean age of 29.31 12.33 years. Twenty-six died from cranial trauma, 8 from stroke and 1 from a brain tumor. The mean time of intubation was 1.69 1.35 days. The mean PaO2 was 470.71 70.82 mmHg. The mean time of ischemia was 201.77 62.64 minutes. Four patients (11.42%) developed PGF and 3 died during the perioperative period. Two additional patients died within the early postoperative period. Survival was 91.4% at one month and 85.5% at three months. The cause of donor death was the only variable that influenced the development of PGF.

CONCLUSION

We observed a low incidence of PGF and of perioperative and early mortality, with one and three month survival rates similar to those reported internationally.

Treatment of American cutaneous leishmaniasis with miltefosine, an oral agent

There is no recognized oral treatment for American cutaneous leishmaniasis. A rising-dose, open-label phase I/II trial of the oral agent miltefosine against Colombian cutaneous leishmaniasis was conducted. Seventy-two male Colombian soldiers (mean weight, 67 kg) received miltefosine at 50-100 mg/day for 3 weeks (for 32 evaluable patients) or at 133-150 mg/day for 3-4 weeks (for 32 evaluable patients). The per-protocol cure rate for 50-100 mg/day was 21 (66%) of 32 patients. The per-protocol cure rate for 133-150 mg/day was 30 (94%) of 32 patients (P =.01, by use of Fisher's exact test). The historic per-protocol cure rate for standard injections of antimony is 93%. "Motion sickness" that did not interfere with normal duties was experienced by 40% of patients and was dose related. Vomiting and diarrhea were reported on approximately 2% of treatment days. In this uncontrolled study of oral miltefosine for treatment of patients with American cutaneous leishmaniasis, a dosage of approximately 2.25 mg/kg/day for 3-4 weeks was effective and tolerated.

A comparison of modelling techniques used to characterise oxygen uptake kinetics during the on-transient of exercise

We compared estimates for the phase 2 time constant (tau) of oxygen uptake (VO2) during moderate- and heavy-intensity exercise, and the slow component of VO2 during heavy-intensity exercise using previously published exponential models. Estimates for tau and the slow component were different (P < 0.05) among models. For moderate-intensity exercise, a two-component exponential model, or a mono-exponential model fitted from 20 s to 3 min were best. For heavy-intensity exercise, a three-component model fitted throughout the entire 6 min bout of exercise, or a two-component model fitted from 20 s were best. When the time delays for the two- and three-component models were equal the best statistical fit was obtained; however, this model produced an inappropriately low DeltaVO2/DeltaWR (WR, work rate) for the projected phase 2 steady state, and the estimate of phase 2 tau was shortened compared with other models. The slow component was quantified as the difference between VO2 at end-exercise (6 min) and at 3 min (DeltaVO2 (6-3 min)); 259 ml x min(-1)), and also using the phase 3 amplitude terms (truncated to end-exercise) from exponential fits (409-833 ml x min(-1)). Onset of the slow component was identified by the phase 3 time delay parameter as being of delayed onset approximately 2 min (vs. arbitrary 3 min). Using this delay DeltaVO2 (6-2 min) was approximately 400 ml x min(-1). Use of valid consistent methods to estimate tau and the slow component in exercise are needed to advance physiological understanding.

[Model of mortality risk in stage I non-small cell bronchogenic carcinoma]

OBJECTIVE

To develop and validate a mortality risk model for patients with resected stage I non-small cell bronchogenic carcinoma (NSCBC).

PATIENTS AND METHOD

Tumors from 798 patients with diagnoses of NSCBC were resected and classified in stage I. The Kaplan-Meier method and Cox's proportional hazard model were used to analyze the influence of clinical and pathologic variables on survival.

RESULTS

Univariate analysis revealed that age (p = 0.0461), symptoms (p = 0.0383), histology (p = 0.0489) and tumor size (p = 0.0002) and invasion (p = 0.0010) affected survival. Size (p = 0.0000) and age (p = 0.0269) were entered into multivariate analysis. Each patient's risk was estimated by applying the regression equation derived from multivariate analysis; the mean was 1.47 +/- 0.31 (range 0.68 to 2.92). The series was divided into three groups by degree of risk (low, intermediate and high), establishing the cutoff points at 1.16 and 1.78 (standard deviation of the mean). Five-year survival rates were 85%, 62% and 46%, respectively (p = 0.0000). To validate the model's predictive capacity, the series was divided randomly into two groups: the study group with 403 patients and the validation group with 395. Age (p = 0.0295), symptoms (p = 0.0396), tumor size (p = 0.0010) and invasion (p = 0.0010) affected survival in the univariate analysis. Size (p = 0.0000) and age (p = 0.0358) were entered into Cox's model. Mean risk was 1.94 +/- 0.36 (range 0.98 to 3.32). The series was divided into three risk groups, with cut-off points established at 1.58 and 2.30. Five year survival rates were 90%, 62% and 46% for the low, intermediate and high risk groups, respectively (p = 0.0000). The same model proved able to identify risk when applied to the validation group, in which five-year survival rates were 78%, 61% and 48%, respectively (p = 0.0000).

CONCLUSIONS

Risk models can identify patient subgroups, potentially influenced by co-adjuvant treatment, as well as facilitate comparison of patient series.

[Splenectomy in a patient with beta thalassemia intermedia and severe hemolytic anemia]

A 36-year-old woman with beta thalassemia intermedia suffered a hemolytic crisis secondary to Epstein-Barr virus infection. She was given a transfusion of phenotypically compatible blood. However, severe hemolysis persisted (with hemoglobin levels around 4 g/dl) in spite of gamma globulin and corticosteroid administration. Emergency therapeutic splenectomy was performed. We discuss intraoperative management in situations of severe anemia, concluding that it is possible to survive significant decreases in hemoglobin concentration with cardiocirculatory reserve and respiration intact, maintaining normal volume.

[Patients with end-stage chronic renal insufficiency on programmed withdrawal from dialysis]

The voluntary discontinuation of dialysis by patients is a common mode of death in dialysis programmes. Unfortunately the Spanish experience has not been related in the nephrological literature. Initiation of, and withdrawal from, dialysis pose ethical questions for medicine in the 21st century. The dialysis population is aging and they have multiple medical problems. The choice may be between prolongation of quantity or quality of life. We evaluated a protocol for initiation of dialysis in patients with end stage renal failure and their subsequent withdrawal. We determined the factors predicting withdrawal of dialysis and revised the protocol to take account of these. We carried out an opinion poll of doctors and nurses about the effectiveness of the protocol. We studied prospectively the reasons for death of patients in the last seven years.

RESULTS

Thirty patients were withdrawn from dialysis out of 116 who died during treatment by hemodialysis or continuous ambulatory peritoneal dialysis (CAPD) in the last seven years. Vascular nephropathy is the principal disease predicting withdrawal from dialysis; the main precipitating cause is mental incapacity. The availability of a protocol for withdrawal of dialysis is well received by doctors and nurses and it engenders moral and legal calm when facing difficult decisions. Twenty-six per cent of deaths on regular dialysis are the result of withdrawal of treatment.

Labelling of Re-ABP with 188Re for bone pain palliation

Etidronate and medronate have been labelled with technetium-99m (99mTc-HEDP, 99mTc-MDP) for bone scanning and, with rhenium-188 (188Re-HEDP) to palliate the pain resulting from bone metastases. The objective of this study was to label alendronate, ABP, a new bisphosphonate, with SnF2-reduced-188Re. The reagents for the 5 mg ABP kit were SnF2, KReO4 and gentisic acid at acid pH. The chemical, spectroscopic and microscopic characteristics, quality control, rat bone uptake of [188Re]Re-ABP and similarities with 99mTc-ABP are presented. We conclude that this is a promising new radiopharmaceutical for bone metastases pain palliation.

Peroxisome proliferator activator receptor-gamma agonists and 15-deoxy-Delta(12,14)(12,14)-PGJ(2) induce apoptosis in normal and malignant B-lineage cells

The research described herein evaluates the expression and functional significance of peroxisome proliferator activator receptor-gamma (PPAR-gamma) on B-lineage cells. Normal mouse B cells and a variety of B lymphoma cells reflective of stages of B cell differentiation (e.g., 70Z/3, CH31, WEHI-231, CH12, and J558) express PPAR-gamma mRNA and, by Western blot analysis, the 67-kDa PPAR-gamma protein. 15-Deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)), a PPAR-gamma agonist, has a dose-dependent antiproliferative and cytotoxic effect on normal and malignant B cells as shown by [(3)H]thymidine and 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide assays. Only PPAR-gamma agonists (thiazolidinediones), and not PPAR-alpha agonists, mimicked the effect of 15d-PGJ(2) on B-lineage cells, indicating that the mechanism by which 15d-PGJ(2) negatively affects B-lineage cells involves in part PPAR-gamma. The mechanism by which PPAR-gamma agonists induce cytotoxicity is via apoptosis, as shown by annexin V staining and as confirmed by DNA fragmentation detected using the TUNEL assay. Interestingly, addition of PGF(2alpha), which was not known to affect lymphocytes, dramatically attenuated the deleterious effects of PPAR-gamma agonists on B lymphomas. Surprisingly, 15d-PGJ(2) induced a massive increase in nuclear mitogen-activated protein kinase activation, and pretreatment with PGF(2alpha) blunted the mitogen-activated protein kinase activation. This is the first study evaluating PPAR-gamma expression and its significance on B lymphocytes. PPAR-gamma agonists may serve as a counterbalance to the stimulating effects of other PGs, namely PGE(2), which promotes B cell differentiation. Finally, the use of PGs, such as 15d-PGJ(2), and synthetic PPAR-gamma agonists to induce apoptosis in B-lineage cells may lead to the development of novel therapies for fatal B lymphomas.

[The "quality of life" concept in medical students and postgraduate residents in a university hospital]

We investigated the quality of life's concept and its uses by both residents and interns as well as last year medical students in the University Hospital in Caracas (HUC). A random sample by strata, without replacement of 123 persons, completed a self administered questionnaire which included a set of closed questions and one of open questions related to the quality of life's concept. The mean age was 29 years for both sexes (3.55 standard deviation or SD). There was not a statistically significant difference between males and females. More than 50% read about quality of life in either newspapers, journals and fiction literature. There was no difference among the groups (p = 0.25). Only 68% had heard in a different sort of academical institution the term "quality of life" such as in the school of medicine, highschool or in some discussion groups with no differences among the groups (p = 0.15). However, there was no agreement as from whom and where they learned about quality of life (p < 0.001). Although everybody considered that the quality of life was an important element in medical actions such as diagnostic or therapeutics, its importance was reduced for diagnosis compared to treatment (p < 0.0001). All the elements that were considered as part of the concept were also considered as important, regardless of the group and was statistically significant (p < 0.05). The open question analysis showed that the non-medical definitions represent 85.15% of the group, 50% out of them included terms of potentiality or condition. Among the elements included in the definition was the social in 27.65%, psychological in 23.53% and, the economical in 12.35% of the questionnaires. The great majority of the "quality of life" definitions did not include a clearly defined subject and in many cases it was exclusively related to ill persons. Finally, there is an informal and not well oriented form of learning about "quality of life" in residents, interns and last year medical students with a lack of a good applicability in the medical practice. Therefore, there is a need for a formal training on quality of life along the medical studies and its uses in the medical practice in general and with special emphasis on diagnosis and therapeutics.

Temporal development of autoreactive Th1 responses and endogenous presentation of self myelin epitopes by central nervous system-resident APCs in Theiler's virus-infected mice

Theiler's murine encephalomyelitis virus (TMEV)-induced demyelinating disease is a chronic-progressive, immune-mediated CNS demyelinating disease and a relevant model of multiple sclerosis. Myelin destruction is initiated by TMEV-specific CD4(+) T cells targeting persistently infected CNS-resident APCs leading to activation of myelin epitope-specific CD4(+) T cells via epitope spreading. We examined the temporal development of virus- and myelin-specific T cell responses and acquisition of virus and myelin epitopes by CNS-resident APCs during the chronic disease course. CD4(+) T cell responses to virus epitopes arise within 1 wk after infection and persist over a >300-day period. In contrast, myelin-specific T cell responses are first apparent approximately 50-60 days postinfection, appear in an ordered progression associated with their relative encephalitogenic dominance, and also persist. Consistent with disease initiation by virus-specific CD4(+) T cells, CNS mononuclear cells from TMEV-infected SJL mice endogenously process and present virus epitopes throughout the disease course, while myelin epitopes are presented only after initiation of myelin damage (>50-60 days postinfection). Activated F4/80(+) APCs expressing high levels of MHC class II and B7 costimulatory molecules and ingested myelin debris chronically accumulate in the CNS. These results suggest a process of autoimmune induction in which virus-specific T cell-mediated bystander myelin destruction leads to the recruitment and activation of infiltrating and CNS-resident APCs that process and present endogenous myelin epitopes to autoreactive T cells in a hierarchical order.

Divergent roles for p55 and p75 tumor necrosis factor receptors in the pathogenesis of MOG(35-55)-induced experimental autoimmune encephalomyelitis

To clarify the role of tumor necrosis factor (TNF) in the inflammatory aspects of autoimmunity vs its potential role in the apoptotic elimination of autoreactive effector cells, we assessed the roles of the p55 (TNFR1/Tnfrsf1a/CD120a) and p75 (TNFR2/Tnfrsf1b/CD120b) TNF receptors in the pathogenesis of MOG(35-55)-induced experimental autoimmune encephalomyelitis (EAE). TNFR p55/p75(-/-) double knockout mice were completely resistant to clinical disease. TNFR p55(-/-) single knockout mice were also totally resistant to EAE, exhibiting reduced MOG(35-55)- specific proliferative responses and Th1 cytokine production, despite displaying equivalent DTH responses. Importantly, IL-5 was significantly increased in p55(-/-) mice. In contrast, p75(-/-) knockout mice exhibited exacerbated EAE, enhanced Th1 cytokine production, and enhanced CD4(+) and F4/80(+) CNS infiltration. Thus, p55/TNFR1 is required for the initiation of pathologic disease, whereas p75/TNFR2 may be important in regulating the immune response. These results have important implications for therapies targeting p55 and p75 receptors for treating autoimmune diseases.

Effect of neuropeptide Y on the sympathetic contraction of the rabbit central ear artery during cooling

In order to analyse the effect of neuropeptide Y (NPY) on the cutaneous vascular response to sympathetic nerve stimulation during cooling, the isometric response of isolated 2-mm segments of the rabbit central ear (cutaneous) artery was recorded at 37 degrees C and during cooling (30 degrees C). Electrical field stimulation (4-16 Hz) at 37 degrees C produced a frequency-dependent contraction, which was reduced during cooling (45% for 16 Hz) and potentiated by NPY (10(-8), 3x10(-8) and 10(-7) M), this potentiation being greater at 30 degrees C than at 37 degrees C. The NPY-induced potentiation of the contraction elicited by electrical field stimulation (8 Hz) was abolished by an antagonist of Y1 subtype NPY receptors, BIBP3226 (10(-6) M), at 37 degrees C and 30 degrees C, reduced by phentolamine (10(-6) M) at 30 degrees C but not at 37 degrees C, was not modified by the purinoceptor antagonist PPADS (3x10(-5) M) and was reduced by application of both phentolamine and PPADS at both temperatures. Both NiCl2 (10(-3) M) and verapamil (10(-5) M) abolished the potentiating effect of NPY at 37 degrees C and reduced it at 30 degrees C. Neither application of an inhibitor of nitric oxide synthesis, L-Nomega-nitro-arginine (L-NOARG, 10(-4) M), nor endothelium removal modified the potentiating effect of NPY at 37 degrees C or 30 degrees C. NPY (10(-8), 3x10(-8) and 10(-7) M) potentiated in a concentration-dependent way the arterial contraction in response to exogenous noradrenaline (10(-8)-10(-4) M) at 30 degrees C but not at 37 degrees C, and it increased the response to ATP (10(-4)-10(-2) M) at both temperatures. Therefore, in cutaneous (ear) arteries: (1) NPY potentiates the sympathetic response at 37 degrees C and at 30 degrees C, (2) this potentiating effect of NPY was more marked at 30 degrees C than at 37 degrees C, probably because of greater potentiation of the alpha-adrenoceptor response during cooling, and (3) the potentiating effect of NPY at both temperatures is mediated by NPY receptors of the Y1 subtype, is dependent of Ca2+ channels and is independent of the release of endothelial nitric oxide.

[Cardiopulmonary dynamics during a maximal exertion test in Mexican endurance athletes]

AIM

To search for cardiopulmonary (CP) kinetic and dynamic differences between Mexican resistance athletes (RES = 10) and non athletes (NON = 19).

METHOD

From the expired volume (Ve), measured by an open circuit spirometry, we calculated both VO2 and VCO2 during stress test while the volunteer pedalled seated on an electronic cycloergometer that started at 50 W.2 min-1 followed by increments of 25 W.2 min-1 each, until VO2máx was reached. The exercise transient time course (min) response (VO2, VCO2, Ve and heart rate, HR; and also O2 pulse, PulO2) was transformed to seconds and modelled by computer using linear regression technique by the interactive minimum squares method, and the mean response time (MRT) was used as an overall kinetic CP parameter.

RESULTS

The transient MRTs for VO2, VCO2 and Ve were slow in RES compared to NON. While the transient CP dynamics in NON lasted MRT_VO2 < (MRT_PulO2, MRT_FC) < MRT_VCO2 < MRT_Ve; the RES: both MRT_PulO2 and MRT_HR shifted to the right ((MRT_VO2, MRT_VCO2) < (MRT_PulO2, MRT_FC) < MRT_Ve). The relationships between the best sport profit mean velocity and both the MRT_VO2, MRT_VCO2 and MRT_PulO2 (GEK = gas exchange kinetics) showed fast_RES and slow_GEK, and slow_RES and fast_GEK.

CONCLUSION

The transient CP kinetics was slow in RES compared NON. It is possible to distinguish cardiopulmonary kinetic differences among resistance athletes holding different sport profiles.

PPAR-gamma-mediated regulation of normal and malignant B lineage cells

Prostaglandins of the E-series stimulate B lymphocytes by enhancing immunoglobulin-class switching and antibody production. Little is known about whether or not other prostaglandins affect B lineage cells and perhaps counterbalance the stimulatory effects of PGE2. PGD2 is a major product of cyclooxygenase in bone marrow and in macrophages, suggesting a role for this lipid product in immunological responses. PGD2 undergoes dehydration to the biologically active prostaglandin 15-deoxy-delta 12,14-PGJ2 (15d-PGJ2) that binds to the nuclear receptor known as peroxisome proliferator-activated receptor gamma (PPAR-gamma). We found that normal mouse B cells and a variety of B lymphoma cells (e.g., 70Z/3, WEHI-231, CH12, and J558) express PPAR-gamma mRNA and the 67-kDa PPAR-gamma protein. 15d-PGJ2 had a dose-dependent antiproliferative/cytotoxic effect on normal and malignant B cells, as shown by 3H-thymidine and MTT assays. Only PPAR-gamma agonists (i.e., thiazolidinediones) mimicked the effect of 15d-PGJ2 on B lineage cells, indicating that the mechanism by which 15d-PGJ2 negatively affects B lineage cells involves PPAR-gamma. The mechanism whereby PPAR-gamma agonists induced cytotoxicity is via apoptosis, as shown by Annexin V assay. PPAR-gamma agonists may serve as a counterbalance to the stimulating effects of PGE2, which promotes B-cell differentiation. The use of prostaglandins, such as 15d-PGJ2, and synthetic PPAR-gamma agonists to induce apoptosis in B lineage cells may lead to the development of therapies for fatal PGE2-resistant B lymphomas.

[Small-cell nonanaplastic bronchogenic carcinoma. The new stage I]

OBJECTIVE

To validate updated guidelines for stage I classification of patients with differentiated small-cell bronchogenic carcinoma.

METHODS

Seven hundred seventeen tumors of differentiated small-cell bronchogenic carcinoma were resected in our hospital and given a TNM classification of stage I based on guidelines recently issued by the Spanish Society of Pneumology and Chest Surgery (SEPAR). Survival was calculated using the Kaplan-Meier method and curves were compared with a log-rank test. The Cox proportional hazards model was used to analyze multiple variables.

RESULTS

One hundred forty-two cases were classified as stage IA and 575 as stage IB. Survival was significantly longer for stage IA than for stage IB (p = 0.0021). The prognosis was significantly better for stage IA patients who were asymptomatic (p = 0.0380) or who had tumors < or = 2 cm in diameter (p = 0.0431). In stage IB, histologic grade (p = 0.0104) and tumor diameter (p = 0.0002) significantly affected survival. A noteworthy finding was the 82% survival at five years in a group of 66 patients with a maximum tumor diameter of 3 cm classified as T2N0M0 due to invasion of the visceral pleura or to proximal involvement of a lobar bronchus at a site > 2 cm from the carina; that survival rate was not significantly different from survival for stage IA (p = 0.1573). Multivariate analysis showed that tumor diameter (p = 0.0272) was of prognostic importance in stage IA, while tumor diameter (p = 0.0005) and histologic grade (p = 0.0092) were relevant in stage IB.

CONCLUSION

The new staging guidelines for differentiated small-cell bronchogenic carcinoma are nearer to prognostic reality given that survival for stage IA patients is significantly longer than for stage IB patients. However, the method continues to have shortcomings in that it fails to achieve one of its main objectives, namely prognostic homogeneity for each subgroup, as indicated by problems related to variables of tumor extension such as diameter, involvement of the visceral pleura or bronchial location, apart from other factors that affect survival.

The Severity of Dependence Scale (SDS) as screening test for benzodiazepine dependence: SDS validation study

AIMS

To assess the validity of the Severity of Dependence Scale (SDS) as a screening test to detect benzodiazepine dependence in regular benzodiazepine users.

METHOD

One hundred regular benzodiazepine users, recruited from neurotic benzodiazepine users attending the Mental Health Outpatient Services of the Canary Islands Health Service, were administered the SDS and responses were compared with the Composite International Diagnostic Interview (CIDI) diagnosis of benzodiazepine dependence. Receiver Operating Characteristic (ROC) analysis was used to determine which cut-off score on SDS allowed the best trade-off between sensitivity and specificity.

RESULTS

SDS was shown to have high diagnostic utility, and a score higher than six on the scale appears to be an appropriate threshold for problematic benzodiazepine use. The SDS had a specificity of 94.2% and a sensitivity of 97.9%, and the area under the curve was of 0.991.

CONCLUSION

The SDS was found to be a valid brief self-report questionnaire for the assessment of benzodiazepine dependence in patients using benzodiazepines.

[The prognosis following surgical resection of small-cell nonanaplastic bronchogenic carcinoma according to the new staging guideline: an analysis of 1433 patients]

OBJECTIVE

To validate current guidelines for staging bronchogenic lung carcinoma.

METHODS

Between 1969 and 1996, small-cell non-anaplastic tumors of bronchogenic carcinoma classified by the recently proposed TNM guidelines of the Spanish Society of Pneumology and Chest Surgery (SEPAR) were resected from 1,433 patients. We used the Kaplan-Meier method to calculate survival and compared the curves using a log-rank test.

RESULTS

A stage IA classification was given to 142 patients and IB to 575. Thirty-seven cases were classified IIA and 336 were IIB. Of the latter, 177 were T2N1M0 and 159 were T3N0M0. Two hundred forty-eight patients were in stage IIIA, 54 T3N1M0, 23 T1N2M0, 120 T2N2M0 and 51 T3N2M0. Ninety-five stage IIIB patients were classified as follows: 37 T4N0M0, 35 T4N1M0, and 23 T4N2M0. Five-year survival for IA patients, at 75% was significantly better than the 60% rate for IB patients (p = 0.0021). Likewise, the prognosis for stage IIA, where five-year survival was 57%, was significantly better than for IIB at 39% (p = 0.0434). The prognosis for patients classified as T1NM0 was better than for those classified as T2N1M0, which was 38% (p = 0.0320). The survival of those classified as T3N0M0 (42%) was not significantly different from that of T1N1M0 (p = 0.1754) or T2N1M0 (p = 0.5360) patients. We found no significant difference between T1N1M0 and stage IB (p = 0.3847) patients. Among stage III patients, we observed no difference in survival between stage IIIA and IIIB (p = 0.1914). In stage IIIA, patients classified as T3N2M0 had a significantly lower rate of survival (p = 0.0399). The presence of mediastinal ganglia in stage IIIB was associated with a lower survival rate (p = 0.0328).

CONCLUSION

The new guidelines for staging non-small cell anaplastic lung carcinoma do not provide consistent prognoses for homogeneous groups of patients, at least not in certain categories.

Viral hyperinfection of the central nervous system and high mortality after hematopoietic stem cell transplantation for treatment of Theiler's murine encephalomyelitis virus-induced demyelinating disease

Theiler's murine encephalomyelitis virus (TMEV) establishes a persistent infection in the central nervous system (CNS) leading to an inflammatory demyelinating disease of the CNS in which the histology and clinical course is similar to multiple sclerosis (MS). Disease pathogenesis is primarily due to T-cell-mediated destruction of myelin, which has been attributed to cytopathic effects of the virus, but immune-mediated destruction of myelin mediated via both virus-specific and myelin-specific T cells appear to play the major role. To determine if bone marrow transplantation would be an effective therapy for a virus-initiated autoimmune disease and to better separate viral cytopathic effects from immune-mediated demyelination, we ablated the immune system of TMEV-infected animals with 1,100 cGy total body irradiation, and then the animal's immunity was reconstituted by transplantation of disease-susceptible SJL/J mice with syngeneic marrow or disease-susceptible DBA/2J with marrow from disease-resistant (C57Bl/6 x DBA/2)F1 (B6D2) donors. Hematopoietic transplant performed after onset of disease resulted in 42% mortality in SJL/J syngeneic transplants, 47% mortality in diseased DBA2 recipients restored with marrow from naive B6D2 donors, and 12% in diseased DBA2 recipients receiving marrow from B6D2 donors previously infected with TMEV. Delayed type hypersensitivity (DTH) to both virion and myelin proteins was decreased in surviving mice that underwent transplantation; however, CNS viral titers were significantly elevated compared with nontransplanted controls. We conclude that a functional immune system with appropriate T-cell responses are important in prevention of lethal cytopathic CNS effects from TMEV. Relevant to the clinical use of bone marrow transplantation, attempts to ablate the immune system in viral-mediated immune diseases or virus-initiated autoimmune disease may have acute and lethal consequences. Our results raise concern about the attempted use of autologous hematopoietic transplantation in patients with MS, an autoimmune disease with a suspected virus etiology, particularly if the graft is aggressively depleted of lymphocytes.

Preresectional chemotherapy in stage IIIA non-small-cell lung cancer: a 7-year assessment of a randomized controlled trial

In 1989, we began a multicenter study to evaluate the potential benefit of preoperative chemotherapy with cisplatin, ifosfamide and mitomycin over surgery alone in CT-visible N2 non-small-cell lung cancer. We present here a 7-year assessment of this randomized trial. Sixty patients were randomized to receive either surgery alone or three cycles of mitomycin 6 mg/m2, ifosfamide 3 g/m2 and cisplatin 50 mg/m2, given intravenously on day 1 of each cycle at 3-week intervals and followed by surgery. All patients received thoracic irradiation after surgery. The resected tumors were evaluated for the presence of K-ras gene point mutations. Treatment arms were well-balanced in characteristics such as gender, age, histology, and tumor size. Mediastinoscopy and/or mediastinotomy (Chamberlain procedure) with a biopsy was performed in all patients with N2 stage detected by CT scan of the chest (83% of the patients in the preresectional chemotherapy arm and 63% of those in the surgery arm). In eight of the 25 patients (32%) who had mediastinoscopy in the preresectional chemotherapy arm, the initially positive mediastinal lymph nodes were downstaged. For the 30 patients who received preresectional chemotherapy, overall median survival was 22 months (95% CI, 13.4 30.6). Of the 30 patients who received surgery alone, overall median survival was 10 months (95% CI, 7.4-12.6; P = 0.005 by the log rank test). Updated survival data reveals a plateau in the preresectional chemotherapy group, and this still significant long-term survival benefit prompts us to hypothesize that even with short-term preresectional chemotherapy, the natural history of still resectable CT-visible N2 non-small cell lung cancer is favorably altered. The results of our study mirror the long-term survival recently reported in the MD Anderson randomized study.

Ultrastructural studies of dorsal root axons regenerating through adult frog optic and sciatic nerves

Optic nerves of adult fish and amphibia can successfully regenerate, in part because their glial cells, unlike those of mammals, provide an environment permissive to regrowth. We altered the environment of regenerating dorsal root axons in the frog, Rana pipiens, by grafting segments of optic nerve to test the permissiveness of CNS glial cells to other sensory neurons. We compared these preparations to grafts of segments of sciatic nerve. After allowing various times for survival, light and electron microscopy were used to evaluate the grafts. An agglomeration of astrocytes, tightly joined by desmosomes, initially formed in the center of the optic nerve grafts. Around this grew regenerating dorsal root axons, accompanied by Schwann cells. At early stages, some axons formed dilated terminal structures, which were not seen in peripheral nerve grafts. The appearance of blood vessels within the graft and the dispersion of cells allowed larger numbers of axons to grow through the graft. By eight weeks, 48% of dorsal root sensory axons had grown through optic nerve grafts, compared to 84% for sciatic nerve. These results suggest that astrocytes from optic nerve are not inhibitory to, and provide a suitable substrate for, regrowing sensory neurons.

Translation to Spanish, reproducibility, and cross-cultural adaptation of the Miller-Rahe Recent Life Change Questionnaire in Venezuela

OBJECTIVE

To translate into Spanish a version of the Miller-Rahe Recent Life Change Questionnaire and to adapt it to Venezuelan cultural values.

METHODS

The Spanish version and cross-cultural adaptation of the Miller-Rahe Recent Life Change Questionnaire was done following recently proposed guidelines to preserve semantic, idiomatic, and conceptual equivalence in translations of health assessment instruments. We performed one or more translations into the new language, as well as back-translation, test-retest reliability, and weighting score for the translated instrument.

RESULTS

A Spanish version of the Recent Life Change Questionnaire was obtained. Validity of translations was demonstrated with a significant agreement for the nonliteral translations (kappa value = 0.97, P < 0.05). The conceptual equivalence was demonstrated by significant agreement in the back-translations (kappa value = 0.84, P < 0.05). The translated instrument met acceptable levels of reliability, as assessed by Spearman's rank correlation coefficients (> 0.60 for all categories of the questionnaire). The cross-cultural adaptation of the translated instrument required addition and exclusion of items as well as changes of the ranking and scaling of life units in the original questionnaire.

CONCLUSION

A valid and reliable Spanish version of the Miller-Rahe Recent Life Change Questionnaire was produced and adapted to Venezuelan cultural values.

Double-blind, randomized, placebo-controlled assessment of chloroquine/primaquine prophylaxis for malaria in nonimmune Colombian soldiers

To improve upon the efficacy of primaquine prophylaxis for malaria (94%, Plasmodium falciparum malaria; 85%, Plasmodium vivax malaria), we administered chloroquine (300 mg weekly) in combination with primaquine (30 mg daily) to nonimmune Colombian soldiers during 16 weeks of patrol in a region of endemicity and for a further 1 week in base camp. The occurrence of symptomatic parasitemia was determined during those 17 weeks and during a further 3 weeks in base camp. The protective efficacy for the chloroquine/primaquine treatment group of 100 subjects, compared with that for the placebo treatment group of 51 subjects, was 88% (95% confidence interval [CI], 76-94) against all types of malaria, 89% (95% CI, 61-97) against P. falciparum malaria, and 88% (95% CI, 58-93) against P. vivax malaria. Two chloroquine/primaquine recipients had severe gastrointestinal distress. Comparison of these data with data from a previous study indicates that the addition of chloroquine did not increase the prophylactic efficacy of primaquine.

[Resection of bronchogenic carcinoma invading the diaphragm]

The prognosis for survival when small cell non-anaplastic bronchogenic carcinoma (SCN-ABC) invades the diaphragm has not been clearly established because the diagnosis is rare. We report a series of eight patients who underwent full resection of SCN-ABC with diaphragm invasion. One died during the postoperative period. Mean survival was eight months for the remaining seven and no patient lived five years. All died as a result of remote metastasis. Given these results, we question whether surgery is the most appropriate treatment for these patients.

Effects of vasopressin on the sympathetic contraction of rabbit ear artery during cooling

In order to analyse the effects of arginine-vasopressin on the vascular contraction to sympathetic nerve stimulation during cooling, the isometric response of isolated, 2-mm segments of the rabbit central ear (cutaneous) artery to electrical field stimulation (1-8 Hz) was recorded at 37 and 30 degrees C. Electrical stimulation (37 degrees C) produced frequency-dependent arterial contraction, which was reduced at 30 degrees C and potentiated by vasopressin (10 pM, 100 pM and 1 nM). This potentiation was greater at 30 than at 37 degrees C and was abolished at both temperatures by the antagonist of vasopressin V1 receptors d(CH2)5 Tyr(Me)AVP (100 nM). Desmopressin (1 microM) did not affect the response to electrical stimulation. At 37 degrees C, the vasopressin-induced potentiation was abolished by the purinoceptor antagonist PPADS (30 microM), increased by phentolamine (1 microM) or prazosin (1 microM) and not modified by yohimbine (1 microM), whilst at 30 degrees C, the potentiation was reduced by phentolamine, yohimbine or PPADS, and was not modified by prazosin. The Ca2+-channel blockers, verapamil (10 microM) and NiCl2 (1 mM), abolished the potentiating effects of vasopressin at 37 degrees C whilst verapamil reduced and NiCl2 abolished this potentiation at 30 degrees C. The inhibitor of nitric oxide synthesis, L-NOARG (100 microM), or endothelium removal did not modify the potentiation by vasopressin at 37 and 30 degrees C. Vasopressin also increased the arterial contraction to the alpha2-adrenoceptor agonist BHT-920 (10 microM) and to ATP (2 mM) at 30 and 37 degrees C, but it did not modify the contraction to noradrenaline (1 microM) at either temperature. These results suggest that in cutaneous (ear) arteries, vasopressin potentiaties sympathetic vasoconstriction to a greater extent at 30 than at 37 degrees C by activating vasopressin V1 receptors and Ca2+ channels at both temperatures. At 37 degrees C, the potentiation appears related to activation of the purinoceptor component and, at 30 degrees C, to activation of both purinoceptor and alpha2-adrenoceptor components of the sympathetic response.

Effects of hyperthermia on contraction and dilatation of rabbit femoral arteries

To analyze the effect of hyperthermia on the vascular response, the isometric response of isolated rabbit femoral artery segments was recorded at 37 degreesC and hyperthermia (41 and 44 degreesC). Contraction to potassium (5 x 10(-3)-5 x 10(-2) M) was significantly greater at 41 and 44 than at 37 degreesC and increased by inhibition of nitric oxide (NO) synthesis with Nomega-nitro-L-arginine (L-NNA; 10(-4) M) or endothelium removal at 37 degreesC but not at 41 or 44 degreesC. Norepinephrine (10(-9)-10(-4) M) produced a concentration-dependent contraction greater at 41 or 44 than at 37 degreesC and not modified by endothelium removal or L-NNA at either temperature. Phenylephrine (10(-9)-10(-4) M) produced a contraction increased by warming to 44 degreesC but not to 41 degreesC. The specific alpha2-adrenoceptor agonist BHT-920 produced a weak contraction, reduced by the alpha1-adrenoceptor antagonist prazosin (10(-6) M) and increased at 44 degreesC but not at 41 degreesC. The concentration-dependent contraction to endothelin-1 (ET-1; 10(-11)-10(-7) M) was increased by warming to 41 and 44 degreesC and by endothelium removal or L-NNA at 37 degreesC but not at 41 or 44 degreesC. Response to ET-1 was reduced by endothelin ETA-receptor antagonist BQ-123 (10(-5) M) and ETB-receptor antagonist BQ-788 (10(-5) M). In arteries precontracted with ET-1 (10(-8)-3 x 10(-8) M), relaxation to sodium nitroprusside (10(-8)-10(-4) M) was increased at 41 and 44 degreesC vs. at 37 degreesC, but that of ACh (10(-8)-10(-4) M) or adenosine (10(-8)-10(-4) M) was not different at all temperatures studied. Relaxation to ACh, but not adenosine, was reduced similarly by L-NNA at all temperatures studied. These results suggest hyperthermia in muscular arteries may inhibit production of, and increase dilatation to, NO, resulting in unchanged relaxation to ACh and increased constriction to KCl and ET-1, and may increase constriction to stimulation of alpha1-adrenoceptors by NO-independent mechanisms.

Primaquine prophylaxis against malaria in nonimmune Colombian soldiers: efficacy and toxicity. A randomized, double-blind, placebo-controlled trial

BACKGROUND

Primaquine had a prophylactic efficacy of 90% to 95% against infection with Plasmodium falciparum and P. vivax in Indonesian settlers.

OBJECTIVE

To evaluate the efficacy of primaquine prophylaxis for protecting nonimmune persons from malaria.

DESIGN

Randomized, double-blind, placebo-controlled field study.

SETTING

A malaria-endemic area in Colombia.

PATIENTS

176 healthy, young, nonimmune adult male soldiers.

INTERVENTION

Primaquine, 30 mg/d, or matching placebo during 15 weeks of patrol in the endemic area and 1 week afterward.

MEASUREMENTS

Symptomatic parasitemia was determined over the 16-week intervention period and for 3 weeks in base camp.

RESULTS

Protective efficacy in the primaquine group (122 participants) was 89% (95% CI, 75% to 96%) against all types of malaria, 94% (CI, 78% to 99%) against P. falciparum malaria, and 85% (CI, 57% to 95%) against P. vivax malaria. Six primaquine recipients had mild to moderate gastrointestinal distress, and three had severe distress.

CONCLUSIONS

For prophylaxis against P. falciparum malaria, primaquine has an efficacy and toxicity competitive with those of standard agents. A potential advantage of primaquine is that prophylaxis may be discontinued 1 week after the recipient has left the endemic area.

[Maximal aerobic capacity and sports activity in Mexicans from 13 to 56]

The maximum oxygen uptake (VO2máx) of Mexicans living at 2240 m altitude was measured to obtain reference values relating VO2máx with athletic performance, and to evaluate the impact of this measure of cardiorespiratory fitness and sport activity on the ageing process. Clinically healthy male individuals (N = 138), 13 to 56 years of age, were divided into groups by decade and according to sport participation. The VO2máx maximum values for power (Power max), and heart rate (HRmax) were measured while subjects exercised on an electronic cycle ergometer using an open circuit spirometry system. The maximum power index (PImax) was also calculated. The VO2máx indicated that modes of sport activity positively affected aerobic power and "counteracted" age-related decreased in HRmax-, VO2máx-, Powermax-, and PImax.

Effect of disease stage on clinical outcome after syngeneic bone marrow transplantation for relapsing experimental autoimmune encephalomyelitis

Relapsing experimental autoimmune encephalomyelitis (R-EAE) is an immune-mediated demyelinating central nervous system (CNS) disease. Myeloablation and syngeneic bone marrow transplantation (SBMT), when performed at the peak of acute disease (day 14), prevented glial scarring and ameliorated the disease severity. In contrast, when syngeneic BMT was performed late in chronic phase (day 78), significant glial scarring remained and the clinical severity did not differ significantly from that of the controls. After SBMT in either the acute or chronic phase of disease, the posttransplant immune system remained responsive to myelin epitopes as determined by in vitro proliferation and interferon-gamma (IFN-gamma) production. However, in mice undergoing SBMT, in vivo delayed-type hypersensitivity (DTH) responses were significantly decreased while IFN-gamma RNA levels and inflammatory infiltrates within the CNS were slightly improved. We conclude that failure of SBMT to improve the clinical disease when performed in chronic phase may be due to preexisting glial scarring. We also conclude that in the absence of glial scarring and irreversible neuronal injury, in vivo DTH responses and histology are better predictors of clinical improvement than in vitro proliferation or IFN-gamma cytokine production.

The effect of diazepan and exercise training on selected biochemical and histochemical properties of rat skeletal muscle

The effects of chronic diazepam (D) treatment and exercise training on total body mass (TBM), microsomal protein yield (MPY), calcium uptake by fragmented sarcoplasmic reticulum (SR), muscle fibre cross-sectional area, and both PFK and SDH activities were investigated in the tibialis anterior (TA), soleus (Sol), and plantaris (Plt) muscles of 50 male albino Sprague-Dawley rats. Rats were assigned randomly to control (C), sprint-trained (S), or endurance-trained (E) groups. Training was of 12 weeks duration. One-half of each group received daily intraperitoneally D doses of 5 mg kg-1 of TBM. Exercise reduced TBM (p < 0.05); increased the relative BM of the TA (E = 2.02 +/- 0.02, p < 0.01) and Plt (E = 1.15 +/- 0.02, p < 0.01; S = 1.13 +/- 0.03, p < 0.01), as well as the Ca++ uptake of the Sol SR (C = 0.08 +/- 0.02, E = 0.16 +/- 01, p < 0.05). MPY was elevated in S-Sol (C = 1.12 +/- 0.6, S = 1.52 +/- 0.1, p < 0.01). D elevated Sol MPY as well as TA PFK. S-trained animals had lower mean fibre areas than the E-trained (D-treated and untreated) animals. The elevated relative masses of TA and Plt are explained by a decreased TBM with exercise. The increased Ca++ uptake of the Sol indicates that E enhances this function, and the increased MPY probably implies an increased SR. The D could be responsible for the D-elevated Sol MPY as well as the TA PFK. El D did not reduce neuromuscular activity to a level adversely affecting oxidative enzyme activity, but in the case of PFK activity in the TA muscle, such a reduction was evident.

Infection of a human retinal pigment epithelial cell line with human herpesvirus 6 variant A

A retinal pigment epithelial (RPE) cell line (K-1034) was examined for its susceptibility to human herpesvirus 6 variant A (HHV-6A). Exposure of K-1034 cells to HHV-6A induced the formation of multinucleated giant cells, which was suppressed by an inhibitor of viral DNA synthesis. In the giant cells, herpesvirus nucleocapsids were demonstrated by electron microscopy and the viral glycoprotein B was detected by immunofluorescence assay. These results indicate that K-1034 cells are susceptible to HHV-6A and suggest that HHV-6A has an ability to directly destroy epithelial cells.

Transmission of human herpesvirus 7 through multigenerational families in the same household

BACKGROUND

Human herpesvirus 7 (HHV-7) closely resembles HHV-6 and to a lesser degree cytomegalovirus. HHV-7 infection is usually acquired during early childhood. Primary infection can cause a roseola-like illness but in most cases it is only mildly symptomatic. The majority of adults are seropositive and in contrast to HHV-6 and cytomegalovirus infection, they continue to secrete the virus in their saliva for many years. The mode of intrafamilial transmission of this virus is not well-understood.

METHODS

Saliva samples for virus isolation and DNA restriction analysis were obtained from all 47 members of 6 Japanese families, including 4 families with 3 generations living in the same household.

RESULTS

HHV-7 was isolated from 43 of 47 saliva samples collected from children and adult members of the 6 families (91.5%). In one family the restriction patterns of the maternal grandmother, the mother and the children were similar, and the patterns of the paternal grandmother and the father were similar. In another family the patterns of the father and 5 of 6 children were similar, and those of the mother and the other child were similar. Altogether similar HHV-7 restriction profiles with his or her mother were found in 48% of offspring, and similar profiles with his or her father were found in 28% of offspring.

CONCLUSIONS

The results strongly suggested horizontal transmission of HHV-7 from grandparents to parents to children through close contact within a household. Either parent could transmit HHV-7 to the children.

Role of the purinergic and noradrenergic components in the potentiation by endothelin-1 of the sympathetic contraction of the rabbit central ear artery during cooling

1. To examine the role of the purinergic and noradrenergic components in the potentiation of endothelin-1 on the vascular response to sympathetic nerve stimulation, we recorded the isometric response of isolated segments, 2 mm long, from the rabbit central ear artery to electrical field stimulation (1-8 Hz) under different conditions, at 37 degrees C during cooling (30 degrees C). 2. Electrical field stimulation produced frequency-dependent contraction, which was reduced during cooling (about 60% for 8 Hz). Both at 37 degrees C and 30 degrees C, phentolamine (1 microM) or blockade of alpha(1)-adrenoceptors with prazosin (1 microM) reduced, whereas blockade of alpha(2)-adrenoceptors with yohimbine (1 microM) increased, the contraction to electrical field stimulation. This contraction was increased after desensitization of P2-receptors with alpha, beta-methylene adenosine 5'-triphosphate (alpha, beta-meATP, 3 microM) at 37 degrees C but not at 30 degrees C, and was not modified by blockade of P2-receptors with pyridoxalphosphate-6-azophenyl-2,4'-disulphonic acid (PPADS, 30 microM) at either temperature. 3. Endothelin-1 (1, 3 and 10 nM) at 37 degrees C did not affect, but at 30 degrees C it potentiated in a concentration-dependent manner the contraction to electrical field stimulation (from 28 +/- 6 to 134 +/- 22%, for 8 Hz). At 37 degrees C, endothelin-1 in the presence of phentolamine or prazosin, but not in that of yohimbine, alpha, beta-meATP or PPADS, potentiated the contraction to electrical stimulation. At 30 degrees C, phentolamine or yohimbine reduced, prazosin did not modify and alpha, beta-meATP slightly increased the potentiation by endothelin-1 of the response to electrical stimulation. 4. The arterial contraction to ATP (2 mM) and the alpha(2)-adrenoceptor agonist BHT-920 (10 microM), but not that to (-)-noradrenaline (1 microM), was potentiated by endothelin-1 at both 37 degrees C and 30 degrees C. 5. These results in the rabbit central ear artery suggest that the sympathetic response: (a) at 37 degrees C, could be mediated mainly by activation of alpha(1)-adrenoceptors, with low participation of P2-receptors, (b) is diminished during cooling, probably by a reduction in the participation of alpha(1)-adrenoceptors, and in this condition the response could be mediated in part by P2-receptors, and (c) is potentiated by endothelin-1 during cooling, probably by increasing the response of both postjunctional alpha(2)-adrenoceptors and P2-receptors.

Role of endothelin receptors, calcium and nitric oxide in the potentiation by endothelin-1 of the sympathetic contraction of rabbit ear artery during cooling

1. To examine further the potentiation by endothelin-1 on the vascular response to sympathetic stimulation, we studied the isometric response of isolated segments, 2 mm long, from the rabbit central ear artery to electrical field stimulation (1-8 Hz), under different conditions, at 37 degrees C and during cooling (30 degrees C). 2. Electrical stimulation produced frequency-dependent contraction, which was reduced (about 63% for 8 Hz) during cooling. At 30 degrees C, but not at 37 degrees C, endothelin-1 (1, 3 and 10 nM) potentiated the contraction to electrical stimulation in a dose-dependent way (from 43 +/- 7% to 190 +/- 25% for 8 Hz). 3. This potentiation by endothelin-1 was reduced by the antagonist for endothelin ETA receptors BQ-123 (10 microM) but not by the antagonist for endothelin ETB receptors BQ-788 (10 microM). The agonist for endothelin ETB receptors IRL-1620 (0.1 microM) did not modify the contraction to electrical stimulation. 4. The blocker of L-type Ca2+ channels verapamil (10 microM l-1) reduced (about 72% for 8 Hz) and the unspecific blocker of Ca(2+)-channels NiCl2 (1 mM) practically abolished (about 98%), the potentiating effects of endothelin-1 found at 30 degrees C. 5. Inhibition of nitric oxide synthesis with NG-nitro-L-arginine (L-NOARG, 0.1 mM) increased the contraction to electrical stimulation at 30 degrees C more than at 37 degrees C (for 8 Hz, this increment was 297 +/- 118% at 30 degrees C, and 66 +/- 15% at 37 degrees C). Endothelium removal increased the contraction to electrical stimulation at 30 degrees C (about 91% for 8 Hz) but not at 37 degrees C. Both L-NOARG and endothelium removal abolished the potentiating effects of endothelin-1 on the response to electrical stimulation found at 30 degrees C. 6. These results in the rabbit ear artery suggest that during cooling, endothelin-1 potentiates the contraction to sympathetic stimulation, which could be mediated at least in part by increasing Ca2+ entry after activation of endothelin ETA receptors. This potentiating effect of endothelin-1 may require the presence of an inhibitory tone due to endothelial nitric oxide.