Flow-cytometric assessment of lymphocyte cytokine production in tuberculosis

We assessed by flow-cytometry the Th1/Th2 profiles in peripheral blood lymphocytes (PBL) from patients with active tuberculosis (TB), before and after antituberculous therapy, and from healthy tuberculin-positive and -negative reactors. PBL from patients showed a reduced potential for Th1-cytokine (notably IFN- gamma) production after culture with a policlonal stimulus. When these PBL from patients were cultured with a M. tuberculosis (MTB)-specific antigen such as PPD (10 microg/ml), there was no detectable production of Th1 cytokines. Only the Th2 cytokine IL10 was detected in PBL from patients but not from controls. However, at the site of the tuberculosis disease, T lymphocytes from bronchoalveolar lavage, after culture with PPD, produced IFN- gamma. After completion of tuberculosis therapy, PBL did not produce IL10. These data indicate that the immunosuppression observed in PBL during active tuberculosis infection may be related to IL10 production, and to the compartmentalization of the antigen-Th1 response to sites of active MTB infection.

Pre-irradiation semi-intensive chemotherapy with carboplatin and cyclophosphamide in malignant glioma: a phase II study

We undertook a phase II trial in 17 patients with malignant glioma and large measurable disease to assess response rate and survival with pre-irradiation chemotherapy, using higher doses than standard, trying to improve the outcome. Patients characteristics were: male/female 10/7, age 49 (range 23-59), median Karnofsky index 90% (range 70-100), glioblastoma multiforme/anaplastic astrocytoma 14/3. Treatment consisted of 2 cycles of carboplatin 200 mg/m(2) days 1-3 (or AUC x 8, total dose) plus cyclophosphamide 1000 mg/m(2) days 1-3. One partial response (6.5%) and two stabilizations (13.5%) were observed after pre-irradiation chemotherapy. Twelve out of 15 patients (80%) progressed after chemotherapy. Median survival time was 7.6 months and the survival at 1 year was 33%. Main toxicity was hematologic in the first cycle: neutropenia grade 4 in 100%; thrombocytopenia grade 4 in 73% and grade 3 in 27%; anemia grade 3 in 7%; in the second cycle: neutropenia and thrombocytopenia grade 4 in 100% and anemia grade 3 in 50%). No toxic death was related to treatment. This regimen showed limited activity in malignant glioma with large residual disease after surgery or biopsy.

Thermoluminescent response of ZrO2 + PTFE prepared in Mexico to 90Sr/90Y beta particles

Results of studying the thermoluminescent response of undoped ZrO2 + PTFE pellets irradiated with 90Sr/90Y beta particles are presented. Previously, TL characteristics of ZrO2 films doped with rare earths were studied. Phosphor powder was obtained by evaporating a solution of zirconium nitrate in ethanol. In order to stabilise the traps in ZrO2 this phosphor was submitted to different thermal treatments. Optimal thermal treatment consisted in heating at 1100 degrees C for 24 h. With this powder. pressing at room temperature a mixture (2:1) of ZrO2 and polytetrafluoroethylene (PTFE), pellets of 5 mm diameter and 0.8 mm thickness were made. The glow curve of ZrO2 + PTFE pellets exhibited two peaks at 200 and 250 degrees C: its TL response as a function of beta particles dose was linear in the range from 2 to 60 Gy. Repeatability over 10 cycles was 1.8%. Fading at room temperature was 3.8% per month.

Preparation and thermoluminescence properties of aluminium oxide doped with europium

There is little information concerning the use of rare earths as dopants of Al2O3. This paper presents the preparation method and the results of studying the thermoluminescence characteristics of Al2O3:Eu exposed to ultraviolet light. Phosphor powder was obtained by the evaporation method. Optimum dopant concentration was 10% at an evaporation temperature of 700 degrees C. The powder obtained was submitted to thermal treatments at high temperatures in order to stabilise the traps. Diffraction patterns showed amorphous powder up to 500 degrees C; as the temperature was raised crystalline phases of Al2O3 appeared. The photoluminescence spectrum induced by 250 nm UV light exhibited four well defined peaks characteristic of the Eu3+ ion. The glow curve exhibited two peaks at 180 and 350 degrees C. The sensitivity of Al2O3:Eu was 10 times lower than Al2O3:C. The thermoluminescence response was linear from 2.4 to 3000 microJ.cm(-2) of spectral irradiance, and the fading 2% in a month. From these results it can be concluded that Al2O3:Eu has potential as an UV dosemeter.

Insulin-like growth factor-I restores the reduced somatostatinergic tone controlling growth hormone secretion in cirrhotic rats

BACKGROUND/AIMS

An altered growth hormone/insulin-like growth factor-I (GH/IGF-I) axis occurs in advanced liver cirrhosis, characterised by diminished serum levels of IGF-I and increased concentrations of GH. Under normal conditions, GH release is mediated by somatostatin (SS) inhibition. However, the influence of SS on GH release in cirrhosis is not well known. IGF-I supplementation has beneficial effects in experimental cirrhosis, and - under physiological conditions - IGF-I increases SS, inhibiting GH. The aims of this work were to study SS tone in cirrhotic animals and to evaluate whether IGF-I treatment influences SS tone, controlling GH secretion in cirrhosis.

METHODS

We studied the influence of SS on GH secretion by assessing GH response to pyridostigmine (PD) in cirrhotic rats treated and untreated with IGF-I. Liver cirrhosis was induced with CCl4-inhalation for 11 weeks in male Wistar rats. The animals were randomly divided into two groups: CI+IGF (n=12), which received IGF-I treatment for 12 days (2 microg/100 g body wt-1 x d-1) and CI (n=12), which received saline. Healthy controls (CO, n=12) were studied at the same time. On day 13, animals from each group were subdivided into two groups (n=6) in order to explore the effect of a PD intrajugular bolus (10 microg x 100 gbw-1) on serum GH levels (at 0,10,20,30 and 60 min), which were assessed by RIA.

RESULTS

PD bolus did not exert any effect on GH serum levels in the CI group, suggesting a low SS tone in cirrhotic rats. However, PD induced an increase in GH levels into CO and CI+IGF groups. In conclusion, as occurs under normal conditions, the cholinergic system is a significant modulator of GH secretion in experimental liver cirrhosis.

CONCLUSION

Cirrhotic rats have a reduced somatostatinergic tone which can be restored by IGF-I supplementation, suggesting that somatostatin is the main factor involved in the feed-back regulation between GH and IGF-I in cirrhosis.

Factors increasing the mortality rate for patients with ruptured abdominal aortic aneurysms

The objective of this report was to analyze the current surgical results of operative treatment in patients suffering ruptured AAA (abdominal aortic aneurysms) and to define those independent predictive factors for mortality. During a period of 2 years, from January 1996 to December 1997, 144 patients operated on for ruptured AAA in 10 hospitals were included in a multicenter retrospective study. Among the collected variables concerning each patient, those with potential relation to surgical mortality were studied: gender, age, diabetes, hypertension, cardiopathy, pulmonary obstructive disease, preoperative renal dysfunction, symptomatic cerebrovascular disease, peripheral vascular disease, hematocrit on admission, preoperative hypotension < 80 mmHg, loss of consciousness, cardiac arrest, aortic aneurysm location (infrarenal versus non-infrarenal), iliac involvement, aneurysm size, type of rupture, left renal vein ligature, ligature of a patent inferior mesenteric artery, place of aortic cross-clamping, type of grafting, exclusion of both hypogastric arteries, venous technical complications, associated surgery, use of cell saver, intraoperative blood loss, and postoperative complications (renal failure, sepsis, coagulopathy, cardiac complications, pulmonary complications, colon ischemia, prosthetic graft complications, and need for reoperation). Those variables with statistical significance in the univariate analysis were introduced into a multivariate logistic regression model to determine the independent predictors of death. From our results we concluded that surgery for ruptured abdominal aortic aneurysms continues to have an excessively high mortality rate. Even though some preoperative variables could be identified as predictors of mortality, an absolute mortality risk has not yet been determined and the decision to negate surgery should be individualized rather than taken on that basis only. Early diagnosis and treatment of symptomatic aneurysms would improve mortality figures and selective screening should be contemplated.

Characteristics of nitric oxide-induced apoptosis and its target cells in mitogen-stimulated peripheral blood mononuclear cells from HIV+ subjects

The phenomenon of apoptosis observed in lymphoid cells from HIV+ subjects is an important factor contributing to their massive depletion. Several studies have identified nitric oxide (NO) as one of the molecules involved in the apoptosis phenomenon observed during HIV infection. It has been shown that HIV-derived gp120 enhances NO synthesis in cultured cells from HIV+ individuals. Therefore, we tested the potential of two nitric oxide synthase (NOS) inhibitors with different mechanisms of action as preventive agents of in vitro apoptosis, in peripheral blood mononuclear cells (PBMC) from HIV+ subjects. PBMC isolated from these patients always showed higher apoptosis levels than normal subjects, a fact that correlated with overproduction of NO and with reduction of mitochondrial transmembrane potential in these cells. We identified the CD8+ T lymphocyte sub-population as the major apoptosis target in PBMC cultures. Treatment with NO inhibitors N(G)-monomethyl-L-arginine (L-NMMA) and dexamethasone (DEX) inhibited spontaneous and mitogen-induced apoptosis, while reducing mitochondrial alterations in PBMC from both normal (30%) and HIV+ (70%) subjects. The development of apoptosis in target cells correlated with their mitochondrial transmembrane potential impairment and with increased expression of Fas (CD95) molecules. These results offer additional alternatives for the manipulation of cellular depletion in HIV disease.

[Severe gastrointestinal complications potentially associated with the use of non-steroidal anti-inflammatory agents: hospital treatment costs for the National Health System of our country]

BACKGROUND

Non-steroidal antiinflammatory drugs (NSAIDs) produce severe gastrointestinal (G-I) complications in 1-4% of cases which need to be treated into the hospital. The aim of this study has been to assess the hospital cost secondary to treat these complications in our National Health Service (NHS).

MATERIAL AND METHODS

In the first phase a cross-sectional study was performed in order to know the number of patients who were hospitalized due to a severe G-I complication during 1998 in two tertiary hospital in our country. It was reviewed their clinical charts to know whether they had taken any NSAIDs. In those positive cases all resources used during the hospitalization were collected.

RESULTS

In both hospitals studied 38.1% of hospitalized patients for a severe G-I complication had taken any NSAIDs during the same day or previous days. The cost/patient was of 389,831 pesetas. During 1998 in the whole NHS there were 54,623 hospitalizations owing to the same reason. Assuming that 38.1% of them had also taken any NSAIDs, 20,811 patients would have suffered a severe G-I complication potentially due to the intake of NSAIDs. Extrapolating the cost/patient obtained in both hospitals to the global number of patients hospitalized into the NHS, the cost of treating all severe G-I complications related to the consumption of NSAIDs during 1998 was of 8,112 millions pesetas.

CONCLUSIONS

Bearing in mind the elevated prevalence of osteo-articular pathology in our country and the high consumption of NSAIDs for its treatment, the coming of new therapeutic options with a better safety profile would mean an important resources' saving for our NHS.

[Risk factors associated to tuberculosis patients with positive sputum microscopy]

OBJECTIVE

The main factor responsible for producing new cases of tuberculosis by exogen transmission is the existence of Mycobacterium tuberculosis in the sputum of tuberculosis patients. The objective of this study was to determine the risk factors associated to positive smear tuberculosis cases in Lleida (Spain).

METHODS

We studied new cases of tuberculosis over the period 1992-1998. The variables considered were: age, gender, coinfection with HIV, injection drug use (IDU), consumption of alcohol, existence of caverns in thorax X-ray, and laboratory results of direct smear examination. We calculated the incidence rates for 100,000 persons-year. The association between the dependent variable case of tuberculosis with positive Mycobacterium tuberculosis smear and the remaining independent variables were assessed obtaining odds ratios (OR) and 95% confidence intervals (CI) (crude cOR and adjusted aOR by non conditional logistic regression).

RESULTS

We detected 905 new cases of tuberculosis. The rates in the period 1992-1998 decreased from 38.8 to 30.8. 44.9% of cases (n = 406) presented a positive direct smear. There was a positive association between the risk of being a positive smear patient and having caverns in thorax x-ray (aOR = 6.8; 95% CI, 4.8-95), being male (aOR = 1.8; 95% CI, 1.3-2.6) and consuming alcohol (aOR = 1.6; 95% CI,1.1-2.3) and this risk was significant lower in those under 15 years old (aOR = 0.2; 95% CI, 0.1-0.5), and coinfection with HIV (aOR = 0.5; 95% CI, 0.3-0.9).

CONCLUSIONS

HIV infection implies a reduced impact in endemecity of tuberculosis. Study of contacts and the implementation of directly observed treatment must be considered not only for coinfected HIV cases and IDU but also for adult males, especially those who consume alcohol, particularly when they have caverns.

[Usefulness of 201T1 gammagraphy in the diagnosis of carcinoma of the larynx]

For the evaluation of a patient with a laryngeal tumor we need the clinical exam and other exams as the CT scan or MRI. Those studies have a sensitivity of less than 80%. For that reason in the last years there has been a development of new techniques trying to increase the accuracy. The 201Tl SPECT is one of them although it was developed for cardiological purposes. We present our experience in 46 patients with laryngeal tumor in whom we did a 201Tl SPECT as part of the extension study. The sensitivity of the study was 81.6% in the diagnosis of the primary tumor and 46.1% for the neck adenopathies. The 201Tl SPECT can be a good method for the evaluation and detection of recurrences in patients with pharyngo-laryngeal tumor.

Chromosome studies of murine T-cell lymphoid leukemia and derived cell lines

Several cell lines were previously established from a spontaneous murine T-cell leukemia (LB). The aim of this study was to analyze the G- and C-banded karyotypes of the parental LB tumor cells and the derived cell lines. A sensitive cell line (LBL) from which two sublines originated, as well as Vincristine (LBR-V160) and Doxorubicin (LBR-D160) resistant cell lines, were used. Our results showed that LB cells had a pseudo-diploid karyotype with 40 acrocentric chromosomes in which trisomy of chromosome 14 was the most relevant alteration. The sensitive cell line showed this alteration in all metaphases studied; no changes in karyotypes were observed in either subline, despite their dissimilar morphology and growth patterns. In contrast, both resistant lines displayed a more heterogeneous karyotype with no common markers, except for the finding that chromosome 5 was involved in a trisomy in LBR-V160 and in a translocation with chromosome 12 in LBR-D160. Taking into account that the mdr genes are located in chromosome 5, these results suggest a possible association between such alterations and the acquisition of drug resistance.

[Assessment of long-term bone metabolism in patients with relative hypoparathyroidism after changing the calcium concentration of the dialyzate to 3mEq/L]

The existence of a low-bone turnover, non-aluminium related, has been more prevalent in recent years. Factors involved include the increasing number of older and diabetic patients initiating dialysis. Also higher intake of calcium salts and the widespread use of vitamin D derivates may play a role. Demonstration of low PTH secretion allows the recognition of the group of patients with special risk of adynamic bone disease. Little can be done to improve bone remodelling apart from correct management of risk factors previously mentioned. A decrease in dialysate calcium concentration can act in this way, but the long term effect of this procedure on bone mineral density has scarcely been established. The aim of this study was to evaluate the long term effect of lowering the dialysate calcium concentration from 3.5 to 3 mEq/L on bone mass and PTH activity in patients with hypoparathyroidism. We studied 19 patients with PTH < 120 pg/ml and calcemia between 8.5 and 10.5 mg/dl, without aluminium intoxication. Blood levels of Ca, P, alkaline phosphatase, aluminium, iPTH and dialysis doses were measured every 4 months during the two years of follow-up. Phosphate binders were closely monitored. Also calcium dietary feeding was measured by a 5-day dietetic registry at the beginning and 6 and 12 months later. Bone mineral density was assessed by quantitative computed tomography of the distal radius initially and after 18 months. PTH values had significantly increased from the first measurement (from 46 +/- 33 to 97 +/- 68 four months later). At the end of follow up, 8 patients (42%) had reached the objective of maintaining a PTHi above 120 pg/ml, while 11 had not reached it (3 were previously parathyroidectomized and two were diabetic). Only one patient has developed an exaggerated PTH response that has been controlled with oral vitamin D. No bone mineral loss was observed during the follow up. In conclusion, the use of a 3 mEq/l dialysate calcium may improve hypoparathyroidism in a substantial number of patients, avoiding the untoward effect that lower calcium concentration has on bone mineralization.

Effect of Hyaluronic Acid on Corneal Haze in a Photorefractive Keratectomy Experimental Model

PURPOSE

To evaluate the ability of topical hyaluronic acid to decrease corneal opacity after excimer laser photorefractive keratectomy (PRK) in hens.

METHODS

Twenty-four white hens underwent bilateral 193-nm excimer laser PRK to correct -9.00 D of myopia. One eye received postoperative treatment with topical 1% hyaluronic acid six times daily for 3 days; the other eye received phosphate buffered saline. Slit-lamp evaluation by a masked observer was performed for 6 months after PRK, and electron microscopy was carried out at the end of the study.

RESULTS

There were no significant differences in postoperative haze between the eyes treated with hyaluronic acid and those treated with phosphate buffered saline.

CONCLUSION

Topical administration of hyaluronic acid had no effect on the development of corneal haze following PRK in hens.

Nonsevere community-acquired pneumonia: correlation between cause and severity or comorbidity

BACKGROUND

Community-acquired pneumonia frequently constitutes a nonsevere infection manageable at home. However, for these low-risk episodes, the epidemiological features have not been carefully analyzed.

OBJECTIVES

To determine the cause of nonsevere community-acquired pneumonia and to investigate if a correlation exists between cause and severity or comorbidity.

METHODS

During a 3-year period, all patients with nonsevere community-acquired pneumonia, according to the Pneumonia Patient Outcome Research Team prognostic classification (patients in groups 1-3), were included in the study. Causes were investigated through the following procedures: cultures of blood, sputum, and pleural fluid; serologic tests; and polymerase chain reaction methods to detect Streptococcus pneumoniae DNA in whole blood or Mycoplasma pneumoniae and Chlamydia pneumoniae DNA in throat swab specimens.

RESULTS

Of 317 initially included patients, 247 were eligible for the study. A microbial diagnosis was obtained in 162 patients (66%), and the main pathogens detected were S pneumoniae (69 patients [28%]), M pneumoniae (40 patients [16%]), and C pneumoniae (28 patients [11%]). For the 58 patients in prognostic group 1, M pneumoniae was the most prevalent cause, and atypical microorganisms constituted 40 (69%) of the isolated agents. In contrast, for patients in prognostic groups 2 and 3, S pneumoniae was the leading agent, and a significant reduction of M pneumoniae cases and a greater presence of other more uncommon pathogens were observed. The existence of comorbid conditions was not a determining factor for particular causes.

CONCLUSIONS

Among low-risk patients with community-acquired pneumonia, there was a certain correlation between severity and cause. In contrast, the existence of a comorbidity did not have a predictive causative value.

Allergy to dermatophagoides in a group of Spanish gypsies: genetic restrictions

BACKGROUND

Spanish gypsies have traditionally lived as nomads, a reason why few epidemiological studies were done in this ethnic group. However, the high prevalence of asthmatic diseases demonstrated in a population residing in the North of Spain induces us to analyse whether it was due to the influence of genetic loci previously implicated in other population studies as causing the disorders.

METHODS

DRB1* and DQB1* HLA class II, TCR-Valpha8.1, FcepsilonRI-beta Rsa I exon 7 and intron 2, TNF-beta (LTalpha-Nco I) and CD14, were tested for association with asthma and atopy by multiple regression analysis, in 5 families comprising 87 individuals.

RESULTS

Significant associations were found with DQB1*02 (p = 0.02) and DQB1*0301 (p = 0.008) and elevated levels of total serum IgE. A negative association (p = 0.02) was found between total serum IgE and DRB1*14. FcepsilonRI-beta Rsa I-In2 allele 1 was associated with high levels of total serum IgE (p = 0.04). Levels of Der p 1 IgE antibodies were negatively associated with DRB1*11-DQB1*0301 (p = 0.007), and positively with TCR Valpha-8 allele 1 (p = 0.04) and with FcepsilonRI-beta Rsa I-In2 allele 1 (p = 0.009).

CONCLUSIONS

Our results do not show any association between asthma and the genetic loci studied although they do suggest the existence of multiple genetic influences on the allergic response in these families.