Cutaneous hyalohyphomycosis caused by Paecilomyces lilacinus in an immunocompetent host successfully treated with itraconazole: case report and review

Paecilomyces lilacinus is an emerging fungal pathogen that is highly resistant to many antifungal drugs. Skin and subcutaneous soft tissue infections caused by this organism are very unusual. Most cases occur in patients with impaired host defenses or following surgical procedures. There has been only one previous report of a histologically confirmed cutaneous infection due to Paecilomyces lilacinus in a patient without predisposing factors. Described here is the second histopathologically proven case of Paecilomyces lilacinus cutaneous infection in a healthy patient without any apparent portal of entry. Prolonged antifungal chemotherapy with itraconazole led to resolution of the skin lesion. This case of sporadic cutaneous infection due to Paecilomyces lilacinus is believed to be the first reported in Europe and the first histopathologically proven case successfully treated with itraconazole.

Evidence for polymorphism in glisentide

The polymorphism of glisentide has been investigated. Three polymorphs (I, II, III) have been prepared by recrystallization from different solvents and other polymorphic form (IV) was obtained by heating polymorph III at 100 degrees C. In addition, two 1:1 stoichiometric solvates containing carbon tetrachloride and dioxane have been crystallized and finally, an amorphous solid has been obtained. It has been observed that the polarity of the recrystallisation solvent and its ability to form hydrogen bonds have a great influence on the polymorphism of glisentide. The different solid forms of glisentide have been characterized using X-ray diffraction analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), IR spectroscopy and optical microscopy. The recrystallization of polymorph I in melted form II and also the transition of form III-IV have been detected by DSC and X-ray diffraction analysis.

Comparison of methods based on different molecular epidemiological markers for typing of Mycobacterium tuberculosis complex strains: interlaboratory study of discriminatory power and reproducibility

In this study, the currently known typing methods for Mycobacterium tuberculosis isolates were evaluated with regard to reproducibility, discrimination, and specificity. Therefore, 90 M. tuberculosis complex strains, originating from 38 countries, were tested in five restriction fragment length polymorphism (RFLP) typing methods and in seven PCR-based assays. In all methods, one or more repetitive DNA elements were targeted. The strain typing and the DNA fingerprint analysis were performed in the laboratory most experienced in the respective method. To examine intralaboratory reproducibility, blinded duplicate samples were included. The specificities of the various methods were tested by inclusion of 10 non-M. tuberculosis complex strains. All five RFLP typing methods were highly reproducible. The reliability of the PCR-based methods was highest for the mixed-linker PCR, followed by variable numbers of tandem repeat (VNTR) typing and spoligotyping. In contrast, the double repetitive element PCR (DRE-PCR), IS6110 inverse PCR, IS6110 ampliprinting, and arbitrarily primed PCR (APPCR) typing were found to be poorly reproducible. The 90 strains were best discriminated by IS6110 RFLP typing, yielding 84 different banding patterns, followed by mixed-linker PCR (81 patterns), APPCR (71 patterns), RFLP using the polymorphic GC-rich sequence as a probe (70 patterns), DRE-PCR (63 patterns), spoligotyping (61 patterns), and VNTR typing (56 patterns). We conclude that for epidemiological investigations, strain differentiation by IS6110 RFLP or mixed-linker PCR are the methods of choice. A strong association was found between the results of different genetic markers, indicating a clonal population structure of M. tuberculosis strains. Several separate genotype families within the M. tuberculosis complex could be recognized on the basis of the genetic markers used.

A novel anti-apoptosis gene: Re-expression of survivin messenger RNA as a prognosis marker in non-small-cell lung cancers

PURPOSE

The survivin gene is a novel apoptosis inhibitor, related to the baculovirus gene, which is believed to play a pivotal role in fetal development and in cancer. We hypothesised that survivin would be expressed in tumors of patients with non-small-cell lung cancer (NSCLC), and we attempted to determine the influence of survivin re-expression on clinical outcome in patients with up to stage IIIA NSCLC who had undergone radical surgery.

METHODS

We designed a reverse transcriptase polymerase chain reaction (RT-PCR) assay to study the expression of the survivin gene in 83 NSCLC tumor samples and compared the results with relevant clinical and pathologic data.

RESULTS

The RT-PCR identified survivin gene transcript in 71 (85. 5%) of the tumor samples and in only 10 (12%) of the paired, histopathologically normal lung samples. There was no relationship between histologic subtype (squamous v nonsquamous) and survivin gene expression. The 12 patients without survivin expression had significantly better overall survival than the 71 patients with survivin expression (P =.01 by univariate analysis; relative risk, 2. 1). There was no significant correlation between survivin expression and age, sex, cigarette smoking, histologic subtype, tumor differentiation, tumor size, or the presence of mediastinal lymph node metastases in surgical specimens.

CONCLUSION

The survivin gene was expressed in a vast majority of NSCLC tumors. We conclude that survivin transcript is a defining diagnostic marker for NSCLC that may also yield prognostic information and, as an apoptosis inhibitor, be an important target in cancer therapy.

Paclitaxel resistance in non-small-cell lung cancer associated with beta-tubulin gene mutations

PURPOSE

The mechanisms that cause chemoresistance in non-small-cell lung cancer (NSCLC) patients have yet to be clearly elucidated. Paclitaxel is a tubulin-disrupting agent that binds preferentially to beta-tubulin. Tubulins are guanosine triphosphate (GTP)-binding proteins. Beta-tubulin is a GTPase, whereas alpha-tubulin has no enzyme activity. We reasoned that polymerase chain reaction (PCR) and DNA sequencing of the beta-tubulin gene could reveal more information regarding the connection between beta-tubulin mutations and primary paclitaxel resistance.

PATIENTS AND METHODS

Constitutional genomic DNA and paired tumor DNA were isolated from 49 biopsies from 43 Spanish and six American stage IIIB and IV NSCLC patients who had been treated with a 3-hour, 210 mg/m(2) paclitaxel infusion and a 24-hour, 200 mg/m(2) infusion, respectively. Oligonucleotides specific to beta-tubulin were designed for PCR amplification and sequencing of GTP- and paclitaxel-binding beta-tubulin domains.

RESULTS

Of 49 patients with NSCLC, 16 (33%; 95% confidence interval [CI], 20.7% to 45.3%) had beta-tubulin mutations in exons 1 (one patient) or 4 (15 patients). None of the patients with beta-tubulin mutations had an objective response, whereas 13 of 33 (39.4%; 95% CI, 22.8% to 56%; P = 0.01) patients without beta-tubulin mutations had complete or partial responses. Median survival was 3 months for the 16 patients with beta-tubulin mutations and 10 months for the 33 patients without beta-tubulin mutations (P =.0001).

CONCLUSION

We have identified beta-tubulin gene mutations as a strong predictor of response to the antitubulin drug paclitaxel; these mutations may represent a novel mechanism of resistance and should be examined prospectively in future trials of taxane-based therapy in NSCLC.

Influence of polyethylene glycol 4000 on the polymorphic forms of diflunisal

The present study was carried out to investigate the physico-chemical characteristics of diflunisal-PEG 4000 solid dispersions prepared by melting, solvent and melting-solvent methods. The solvents chosen were chloroform, methanol and ethanol-water due to the fact that the drug presents different polymorphic forms in these solvents. The characterization of solid dispersions was performed by X-ray powder diffraction because this technique has the advantage over other identification methods that it can detect both drug and ligand simultaneously. The X-ray diffraction patterns of the diflunisal-PEG systems suggested that the drug/polymer ratio and the solvent nature play an important role in the crystallization of the drug. In this regard, diflunisal crystallizes in form I at high concentrations of the drug (drug/polymer 2:1) in the solidified melt dispersions, however, polymorph III is mainly obtained as the polymer content increases (1:1 and 2:3). Likewise, in solid systems obtained by the solvent and melting solvent methods the drug solidifies in form III in ethanol/water and methanol while polymorph IV crystallizes in chloroform. Finally, DSC thermograms and hot-stage microscopy data of solid dispersions prepared by the melting method have allowed to draw the diflunisal-PEG 4000 solid-liquid phase diagram.

Bilateral lymphocytic alveolitis: a common reaction after unilateral thoracic irradiation

The main aim of the present study was to assess the early diagnostic value of bronchoalveolar lavage (BAL) in radiation-induced lung injury in patients with breast carcinoma. Twenty-six females receiving postoperative radiotherapy for breast cancer were evaluated before and 0, 15, 30, 60, and 180 days after radiotherapy. History, physical examination, chest radiographs, and pulmonary function tests were obtained. BAL, including lymphocyte subsets analysis, was limited to the second evaluation after radiotherapy. A group of 21 healthy females were used as control. Findings after radiotherapy in asymptomatic patients were compared with findings in a group of patients with radiation pneumonitis. Irradiated patients showed a significantly (p<0.01) greater percentage (29.5+/-15.7%) of BAL lymphocytes than controls (6.2+/-3.3%). No statistical differences existed in BAL findings between the irradiated and unirradiated sides of the chest. Percentages of BAL lymphocytes did not differ significantly between patients who developed subsequent pneumonitis (24.5+/-13.5%) and those who did not develop pneumonitis (32.8+/-16.5%). Patients with pneumonitis at the time of BAL had significantly higher (p<0.05) alveolar CD4 subset cells (24.8+/-10.2%) than asymptomatic patients (15.2+/-8.9%). Maximal reductions in total lung capacity (p<0.01), and residual volume (p<0.05) occurred 60 days after irradiation. The early lymphocytic alveolitis induced by unilateral thoracic radiotherapy in most patients with breast cancer is always bilateral and does not predict the subsequent development of radiological evidence of pneumonitis.

A new enzyme electrode for quantification of salicylic acid in a FIA system

This work presents an amperometric biosensor incorporated into a flow configuration comprising salicylate hydroxylase that catalyses the irreversible hydroxylation of salicylate to catechol in the presence of NADH and molecular oxygen, and tyrosinase that further oxidises catechol giving o-quinone which is electrochemically reduced at -100 mV vs. Ag/AgCl yielding catechol and entering the catalytic oxidation and electrochemical reduction cycling which results in signal amplification and, consequently, low limits of detection. Additional incorporation of glucose dehydrogenase in the enzymatic sequence results in regeneration of NADH provided that glucose is present in the carrier stream and incorporation of a dialysis membrane provides operational stability to the biosensor. The analytical characteristics of this catalytic and electrochemical transduction sequence in a FIA system are: a limit of detection of 3.5 10(-6) M (S/N = 3), a sensitivity of 22.6 nA microM(-1) cm(-2), no loss of response at least after 5 h of continuous operation, and a sample frequency of 15 h(-1). Monitoring of salicylate after ingestion of 500 mg of acetylsalicylic acid has been followed in non-pretreated urine samples and the amount of salicylate in several drugs has been also successfully quantified.

Genetic, phenotypic and clinical features of acute lymphoblastic leukemias expressing myeloperoxidase mRNA detected by RT-PCR

Myeloperoxidase (MPO) is found in the azurophilic granules of normal myelocytic cells. Cytochemical staining for MPO activity is used clinically to distinguish myeloid from acute lymphoid leukemias (ALL). However, using a highly sensitive RT-PCR technique, it is possible to detect MPO mRNA in otherwise clear ALL. The significance of this finding remains poorly understood. We have extended our observations to a series of 57 patients with the primary diagnosis of ALL (46 patients tested at diagnosis and 11 cases at relapse). We identified 25 cases (43.8%) of MPO mRNA(+)/enzyme(-) ALL (17 B cell and eight T cell lineage). Expression of myeloid antigens (CD13 or CD33) were detected in nine of them, and remarkably, 18 cases (72%) displayed CD34. Of these 25 MPO mRNA(+) leukemias, 10 (40%) are Bcr-Abl positive (with P210 fusion transcript in five patients while the five remaining cases carried P190 transcript). Moreover, 11 of 16 myeloid negative cases were also negative for any type of Bcr-Abl and MLL rearrangement, indicating that MPO mRNA positivity is not either invariably related to that chromosomal abnormality or necessarily associated with the presence of other myeloid differentiation features. Interestingly, six of these 11 cases are T-ALL, suggesting the presence of some overlapping phase for T and myeloid lineage commitment. Taken together, these findings could suggest a separate biological disease with immature origin and bipotential differentiation capability, which involves B and T-ALL subtypes and should lead to new investigations regarding their prognostic impact.

Influence of propylene glycol and isopropyl myristate on the in vitro percutaneous penetration of diclofenac sodium from carbopol gels

The influence of propylene glycol (PG) on the in vitro penetration of diclofenac sodium (DFS) through a synthetic membrane and abdominal rat skin from carbopol gels was investigated using Franz-type diffusion cells. The combined effect of isopropyl myristate (IPM) and PG was also evaluated. It was found that the penetration through the synthetic membrane was well described by the Higuchi model. The gel containing 40% PG showed the highest release rate, indicating that a releasing maximum exists for PG content which provides the fully solubilized drug in the vehicle. When using rat skin as the barrier, the penetration rate was controlled by the membrane. DFS flux decreased with increasing PG content of the gels due to an increase of the drug affinity to the vehicle. A cosolvent action of PG was evident. However, the combination of PG and IPM resulted in a synergistic enhancement of DFS flux. Maximum enhancing activity was obtained from gels containing 40% PG, which yielded an enhancement ratio of about 8. Increasing IPM content from 3 to 5% increased the flux and decreased the lag time taken to reach a steady-state level.

In vitro inhibition by estrogens of the oxidative modifications of human lipoproteins

Estrogens exert protective actions against atherosclerosis, part of these effects having been ascribed to their antioxidant properties. The aim of this work was to assess the ability of estrogens to prevent the oxidative modifications of low density lipoproteins (LDL) and other plasma lipoprotein fractions whose relationship with atherosclerosis has been less studied. For this purpose, different estrogen compounds were used: natural and synthetic estrogens, and catecholestrogens. The molecules were added in vitro to human LDL and very low density lipoproteins (VLDL) in the presence of Cu2+. The lipoprotein oxidative modifications were determined by measuring the formation of thiobarbituric acid reactive substances, the appearance of conjugated dienes and the degradation of tryptophan groups from the apoproteins. In VLDL, 2-hydroxyestradiol and diethylstilbestrol exerted potent antioxidant effects similar to those found for alpha-tocopherol and probucol. 17beta-Estradiol and 4-hydroxyestradiol also prevented VLDL oxidation, but to a lesser extent. When LDL were used, estrogens similarly exerted antioxidant actions, 2-hydroxyestradiol being the most potent inhibitor. These results show that estrogens, whose antioxidant actions have been demonstrated in other experimental models, also possess the ability to prevent in vitro the oxidative modifications of human plasma LDL and VLDL.

Molecular cloning and characterization of Tap, a putative multidrug efflux pump present in Mycobacterium fortuitum and Mycobacterium tuberculosis

A recombinant plasmid isolated from a Mycobacterium fortuitum genomic library by selection for gentamicin and 2-N'-ethylnetilmicin resistance conferred low-level aminoglycoside and tetracycline resistance when introduced into M. smegmatis. Further characterization of this plasmid allowed the identification of the M. fortuitum tap gene. A homologous gene in the M. tuberculosis H37Rv genome has been identified. The M. tuberculosis tap gene (Rv1258 in the annotated sequence of the M. tuberculosis genome) was cloned and conferred low-level resistance to tetracycline when introduced into M. smegmatis. The sequences of the putative Tap proteins showed 20 to 30% amino acid identity to membrane efflux pumps of the major facilitator superfamily (MFS), mainly tetracycline and macrolide efflux pumps, and to other proteins of unknown function but with similar antibiotic resistance patterns. Approximately 12 transmembrane regions and different sequence motifs characteristic of the MFS proteins also were detected. In the presence of the protonophore carbonyl cyanide m-chlorophenylhydrazone (CCCP), the levels of resistance to antibiotics conferred by plasmids containing the tap genes were decreased. When tetracycline accumulation experiments were carried out with the M. fortuitum tap gene, the level of tetracycline accumulation was lower than that in control cells but was independent of the presence of CCCP. We conclude that the Tap proteins of the opportunistic organism M. fortuitum and the important pathogen M. tuberculosis are probably proton-dependent efflux pumps, although we cannot exclude the possibility that they act as regulatory proteins.

[Clinical factors that affect the detection of BCR-ABL transcripts after allogenic bone marrow transplantation for chronic myeloid leukemia]

BACKGROUND

To evaluate the relationship between clinical parameters and the ability to detect BCR-ABL-positive cells in a series of 27 long survivor patients after allogeneic bone marrow transplantation (BMT) for chronic myelogenous leukemia (CML).

PATIENTS AND METHODS

A total of 78 samples obtained between 1 and 160 months after BMT were analyzed for the presence of the BCR-ABL transcript detected by the reverse-transcription polymerase chain reaction (PCR) using nested primers. Median follow up was 83 months.

RESULTS

16 patients were persistently PCR-positive and 7 patients persistently PCR-negative. The original transcript became negative in four patients. Only two of the positive cases developed hematologic relapse during the period of study. High white blood cell counts before BMT (17.88 vs 10.12 x 10(9)/l; p = 0.008) and immunosuppressive therapy for chronic graft-versus-host disease (p < 0.05) were associated with an increased ability to detect residual BCR-ABL positive cells.

CONCLUSIONS

Our data show that most patient are persistently BCR-ABL positive after BMT for CML. If these findings represents a dynamic balance between the tumour burden prior BMT and the immunological capability of the graft must be confirmed in further studies.

Paediatric Hodgkin's disease in Spain: association with Epstein-Barr virus strains carrying latent membrane protein-1 oncogene deletions and high frequency of dual infections

The present report analyses the distribution of 30-base pair (bp) latent membrane protein-1 (LMP-1) oncogene deletions in 24 cases of Epstein-Barr virus (EBV)-positive paediatric Hodgkin's disease (HD) and 39 normal controls. The 30 bp deletion was identified in 19/24 paediatric HD cases (79.2%), of which seven (29.2%) showed the deleted fragment alone, whereas in the remaining 12 (50%) it was accompanied by the nondeleted fragment. Conversely, the deletion was found in 8/22 (36.4%) EBV-positive healthy children, in two (9.1%) of whom the deleted fragment was alone, and was coinfecting with the nondeleted fragment in the other six (27.3%). The LMP-1 deletion was significantly associated with paediatric HD, both including dual infections (P=0.006) or excluding them (P=0.01). Type 2 EBV was carried by 25% of HD children, whereas all controls harboured type 1 EBV. The 30 bp deletion was present in all the paediatric HD specimens that contained type 2 EBV, suggesting that a deleted type 2 EBV strain may be more tumourigenic than a nondeleted type 2 EBV strain. These findings indicate that EBV strains carrying a 30 bp deletion in the third exon of the LMP-1 oncogene may have a more important role in the pathogenesis of paediatric HD than full-length EBV strains. Dual infection by LMP-1 deleted and nondeleted EBV strains is a frequent event both in healthy children and in the paediatric HD population.

Autologous reconstitution with BCR-ABL-negative haematopoiesis after T cell-depleted allogeneic BMT for CML

We report a patient with Ph chromosome-positive CML who underwent an HLA-identical T cell-depleted BMT from a sibling donor. DNA polymorphism analysis showed complete donor chimaerism after BMT, followed by mixed chimaerism of granulocytes, natural killer cells and B lymphocytes, with T lymphocytes host-derived at day +120 post BMT. From month +20 haematopoiesis was exclusively of host origin in all cell lineages. RT-PCR was used in order to detect residual disease, but at the time, analysis did not show BCR-ABL transcripts. This case is unusual in that non-malignant stem cells of recipient origin survived the transplant and reconstituted haematopoiesis after BMT. Two years post transplant, no molecular or haematological relapse was documented. The observation that subsequent recipient recovery without molecular relapse implies that, at least in this case, the GVL effect can occur in the absence of donor T cells.

Chylothorax in cirrhosis of the liver: analysis of its frequency and clinical characteristics

OBJECTIVES

To ascertain the frequency and to describe the clinical and biochemical features of cirrhotic chylothorax.

DESIGN

A descriptive clinical study.

SETTING

A community teaching hospital.

PATIENTS AND METHODS

Since November 1989 to October 1995, 809 patients with pleural effusions were studied by thoracentesis. Pleural effusions with a concentration of triglycerides higher than 110 mg/dL, a pleural fluid to serum triglyceride ratio higher than 1, and a pleural fluid to serum cholesterol ratio lower than 1 were considered chylothorax.

RESULTS

Twenty-four patients had pleural effusions that complied with all three aforementioned biochemical conditions. Five of these 24 patients (20%), were found to have liver cirrhosis as the main cause of chylothorax and in 3 of them, an abdominal source of the effusion could be demonstrated by intraperitoneal injection of a radioisotope (99mTc-sulfur colloid). The cirrhotic chylous effusions had significantly lower (p<0.005) protein (median, 1.7; range, 1.4 to 2.7 g/dL), lactate dehydrogenase (LDH) (median, 96; range, 77 to 138 IU/L), and cholesterol (median, 25; range, 22 to 64 mg/dL) levels than chylous effusions resulting from other causes (protein: median, 4.1; range, 1.7 to 6.8 g/dL; LDH: median, 351; range, 140 to 8,600 IU/L; and cholesterol: median, 87; range, 38 to 160 mg/dL). Cirrhotic chylothorax was always a transudate according to Light's criteria.

CONCLUSIONS

Chylothorax is a rare and apparently underappreciated manifestation of cirrhosis resulting from transdiaphragmatic passage of chylous ascites. Its uniform biochemical characteristics can facilitate its separation from chylous effusions of different etiology, therefore avoiding potentially harmful diagnostic and therapeutic procedures.

Allelic loss on chromosome 18q as a prognostic marker in stage II colorectal cancer

BACKGROUND & AIMS

Loss of heterozygosity (LOH) on chromosome 18q is frequent in colorectal cancer (CRC) and has been associated with poor prognosis in stage II tumors. This study investigated the frequency of LOH in sporadic CRC and its effect on patient prognosis.

METHODS

One hundred forty-four patients were screened for LOH at 18q by polymerase chain reaction using three polymorphic microsatellite markers.

RESULTS

Nineteen patients were excluded because their tumors showed microsatellite instability in at least one marker. Of the remaining 125 patients, 121 were informative in at least one marker; 45% (54 of 121) showed 18q LOH. Five-year survival was 42% in those with 18q LOH and 73% in those without 18q LOH (P = 0.008). Multivariate analysis showed that tumor side (P = 0.0001) and 18q LOH (P = 0.01) were the only independent prognostic factors. Examining markers individually showed that only the lost of D18S474 had a significant influence on survival in patients with stage II CRC (P = 0.016).

CONCLUSIONS

18q LOH indicates an unfavorable outcome in patients with stage II CRC. Our results emphasize the importance of the 18q21.1 region, where several tumor-suppressor genes have been mapped. Microsatellite analysis may be useful in identifying high-risk patients who might benefit from adjuvant therapy.

Tuberculous pleurisy with or without radiographic evidence of pulmonary disease. Is there any difference?

SETTING

A community teaching hospital in Alicante, Spain.

OBJECTIVE

To assess the characteristics of tuberculous pleurisy (TP) in our hospital, and to evaluate the differences between primary and reactivation forms.

DESIGN

Between January 1984 and December 1993, all human immunodeficiency virus (HIV)-negative patients with TP were included in the study. From September 1987 onward, patients were prospectively studied. Charts, radiography, pleural fluid findings and diagnostic methods were evaluated. Two groups were distinguished according to chest radiographs: those patients with upper lobe lesions, calcified adenopathy and old pleural thickening were considered reactivation forms.

RESULTS

Of the 129 patients (mean age, 31 +/- 18 years), 76% had primary TP and 24% reactivation TP. Differences were found in age (28 +/- 17 vs 40 +/- 18 years, P < 0.01), smoking (43% vs 74%, P < 0.01) and alcohol abuse (23% vs 47%, P < 0.05), weight loss (29% vs 50%, P < 0.05), positive sputum smears and cultures (2% vs 16%, 7% vs 28%, P < 0.01), and number of large effusions (46% vs 26%, P < 0.05), but not in tuberculin reactivity, pleural fluid findings, positive pleural cultures, or presence of pleural granuloma.

CONCLUSION

In our setting, TP predominantly affects young adults. Clinical, immunological, and pleural findings are similar to those of patients with classic symptoms of TP. Older age, smoking and alcohol abuse, smaller effusions and sputum yield are differential characteristics of reactivation forms.

Inhibition by estrogens of the oxidant-mediated mobilization of arachidonic acid in hepatocytes

Oxidative stress is associated with alterations in arachidonic acid (AA) metabolism. The present work was performed to assess the effect of the oxidant tert-butyl hydroperoxide on the release of AA from rat hepatocytes, and the possible preventive actions of estrogens on this effect. The exposure of [14C]-prelabeled cells to tertbutyl hydroperoxide produced the mobilization of [14C]-AA from hepatocyte lipids, both an intracellular [14C]-AA accumulation and an increased release of [14C]-products into the medium being observed. The formation of lysophospholipids was also enhanced significantly in the presence of the oxidant, thus suggesting the involvement of phospholipase A2 (E.C. 3.1.1.4) in the hepatocyte response to tert-butyl hydroperoxide. Estradiol and 2-hydroxyestradiol (25-100 microM) added in vitro to cell suspensions prevented significantly the oxidant- mediated stimulation of AA release, this effect probably being caused by the estrogen inhibitory actions against cellular lipid peroxidation.

Effect of PEG 4000 on the dissolution rate of naproxen

Naproxen is a nonsteroidal anti-inflammatory drug characterized by its low wettability and poor water solubility. Solid dispersions naproxen:PEG 4000 have been prepared in order to improve the solubility and dissolution rate of the drug, since these factors can be the limiting steps for absorption and bioavailability of poorly soluble drugs. X-ray diffraction analysis, infrared spectroscopy and differential scanning calorimetry detected no physico-chemical interaction between the drug and the inert carrier PEG 4000. The phase diagram of the naproxen-PEG 4000 system produced by DSC and hot stage microscopy is reported. The intrinsic dissolution rate of naproxen is calculated. The dissolution kinetics of solid dispersions prepared by the solvent and melt methods are compared with those of free drug and physical mixture. The studies were carried out at 37 degrees C and pH 1.2 according to the dispersed amount method. The dissolution profiles obtained indicate that a significant dissolution enhancement occurs with solid dispersions in comparison with the physical mixture. In addition, the physical mixture showed a dissolution rate higher than the free drug. Dissolution rate constants were determined by fitting the experimental data to the cube root function, to get straight line plots.

Dissolution kinetics for coprecipitates of diflunisal with PVP K30

Diflunisal is a nonsteroidal anti-inflammatory drug that is poorly soluble in water. The present study describes the formulation of solid dispersions of the drug designed to increase its solubility. X-ray diffraction and DSC were used to examine the physico-chemical characteristics of solid dispersions of diflunisal and polyvinylpyrrolidone (PVP) prepared by the solvent method, using percentage proportional compositions ranging from 20:80 to 50:50. X-ray diffraction analysis detected that diflunisal is present in solid dispersions in crystalline or amorphous state depending on the PVP content. The thermal behavior of diflunisal observed in the DSC curves of solid dispersion systems, was attributed to a solid-state interaction. The increased release of the PVP-drug dispersion as compared to the PVP-drug physical mixture was attributed to the formation of a complex resulting from the interaction of the drug and the polymer.

The molecular epidemiology of tuberculosis in Zaragoza, Spain: a retrospective epidemiological study in 1993

SETTING

The incidence of tuberculosis (TB) in Spain is one of the highest in Europe. In Zaragoza region the incidence rate of tuberculosis and the acquired immune deficiency syndrome (AIDS) are close to the national average.

OBJECTIVE

To better define the molecular epidemiology of tuberculosis in an area of Europe where this has not been previously studied.

DESIGN

A retrospective epidemiological study on tuberculosis was conducted in Zaragoza, a region of Spain, in 1993. The study population consisted of 226 patients from whom positive culture and complete clinical and demographic data were available. Mycobacterium tuberculosis strains were typed by standard restriction fragment length polymorphism (RFLP). A cluster was defined as two or more isolates with identical RFLP patterns when five or more copies of IS6110 are present. The 137 non-clustered patients were compared with the 89 clustered patients and studied by using univariate analysis.

RESULTS

Thirty-nine percent of the patients were clustered, suggesting possible recent transmission. Infection with drug-resistant M. tuberculosis was associated with a decreased risk of being in a cluster. The strains isolated from human immunodeficiency virus (HIV)-positive patients were not associated with clustering. We found that immigration was not a major determinant in the total number of TB cases.

CONCLUSION

Immigration, HIV and drug resistance were not associated with recent transmission. More than 50% of the clusters contained two or three patients, indicating that small outbreaks were responsible for most of the tuberculosis cases. Our RFLP typing results indicate that a TB control programme should be implemented in Spain in order to lower transmission of TB.

Solubilization and interaction of sulindac with beta-cyclodextrin in the solid state and in aqueous solution

A sulindac-beta-cyclodextrin complex was obtained by the coprecipitation method. Kneaded solids and physical mixtures were also prepared. The complex was shown by x-ray powder diffraction to be noncrystalline whereas pure drug and any of the other sulindac-beta-CD system were crystalline. the endothermic peak of sulindac due to the fusion of drug disappeared in DSC thermograms for the coprecipitate product, which confirmed the interaction between sulindac and beta-CD in the solid state. After a 1-year storage drug crystals could not be observed by x-ray diffractometry, which indicated that the complex formed was stable. The complex showed the fastest dissolution rate which might be attributed to the high-energy noncrystalline state and the inclusion complex formation in solution. UV spectra were modified and the apparent solubility of the drug increased with the addition of beta-CD, which confirmed the interaction between sulindac and the ligand in solution. The apparent stability constant, K1:1, for the complex at pH 2 and 25, 30, and 37 degrees C was 340, 220, and 160 M-1, respectively, which confirmed the influence of temperature on the complex stability. The value of K1:1 at pH 6 and 25 degrees C was 139 M-1, which indicated that the complex is formed easier with the non-ionized sulindac. The enthalpy change, delta H degree, showed that the binding process is exothermic.

Solubilization and interaction of sulindac with polyvinylpyrrolidone K30 in the solid state and in aqueous solution

In this report the interactions of sulindac with polyvinylpyrrolidone K30 (PVP K30), both in the solid state and in aqueous solution, have been investigated. Solid dispersions of sulindac with PVP K30 were prepared by the solvent method in ethanol from various drug-to-polymer weight ratios. X-ray powder diffraction and differential scanning calorimetry have shown that PVP inhibits the crystallization of sulindac. The stabilization of the noncrystalline state of sulindac was shown by x-ray diffractometry after a 1-year storage. There was a considerable increase in the release rate of the drug when the polymer content was increased and the intrinsic dissolution rate values of these systems were calculated. From the UV spectra a bathochromic shift and a well-defined isosbestic point were observed at pH 2 and 6, which confirmed an interaction between the drug and the polymer in solution. Moreover, the apparent solubility of sulindac has been modified as a function of the polymer concentrations. The binding process between the drug and PVP was exothermic from the stability constant values at 25, 30, and 37 degrees C at pH 2.

Organizing pneumonia in textile printing workers: a clinical description

In April 1992 an outbreak of severe respiratory illness occurred among aerographic textile workers in the area of Alcoi, Autonomous Community of Valencia, Spain. An epidemiological study linked this outbreak to the use of a reformulated aerosolized product, Acramin-FWN. We analyzed clinical, laboratory, and pathological data of the first 14 patients with confirmed organizing pneumonia (OP) secondary to this newly recognized occupational toxicant. The mean age of the patients was 30 yrs. The most common clinical findings were cough (86%), epistaxis (71%), dyspnoea (64%), oppressive chest pain (57%), and crackles (50%). A restrictive functional pattern was evident in 64%. Radiographic findings consisted predominantly of patchy infiltrates in 65% and a micronodular pattern in 35%. Treatment with corticosteroids did not prevent initial progression in 11 of the 14 patients and development of irreversible respiratory failure in five patients. At necropsy, besides features of OP, interstitial fibrosis and diffuse alveolar damage were evident. A low total lung capacity, the presence of crackles at admission, and increases in the alveolar-arterial oxygen difference were predictive of death. The organizing pneumonia caused by the inhalation of Acramin-FWN is characterized by a tendency to evolve into progressive interstitial fibrosis despite the use of corticosteroids. The illness is restricted to the respiratory system and once respiratory failure has developed the prognosis is poor.

Autologous peripheral blood stem cell transplantation (PBSCT) mobilized with G-CSF in AML in first complete remission. Role of intensification therapy in outcome

In order to determine if peripheral blood stem cells (PBSC) collected after priming with G-CSF in AML in first complete remission (CR) can be used for autologous transplantation and to evaluate the efficacy of early intensification therapy as in vivo purging, we studied 35 consecutive patients with AML in first CR. After standard induction and consolidation chemotherapy, 24 of them were treated with one (10 patients) or two (14 patients) cycles of high-dose cytarabine plus etoposide prior to PBSC collection. G-CSF was used as the priming agent. Of the 35 patients scheduled for peripheral blood stem cell transplantation (PBSCT), three relapsed before transplantation, and the 32 remaining underwent PBSCT. High-dose therapy consisted of either total body irradiation plus cyclophosphamide or busulphan plus cyclophosphamide. The median number of CD34+ cells infused was 3.24 x 10(6)/kg (range 0.15-14). The median times to reach a PMN count of 0.5 x 10(9)/l and a platelet count of 50 x 10(9)/l were 12 (8-28) and 30 (11-345) days, respectively. There was no transplant-related mortality. Twelve patients relapsed between 2 and 21 months post-PBSCT. With a median follow-up of 28 months, actuarial disease-free survival (DFS) is 52.41 +/- 9% in the intent-to-treat group and 57.4 +/- 9.8% in patients who underwent PBSCT. The probability of DFS is significantly higher for patients who receive early intensification therapy prior to both PBSC collection and PBSCT as compared with patients that do not: 68.8 +/- 10.27% vs 35.5 +/- 12.6%, P = 0.0418. These results indicate the feasibility of PBSCT in AML using G-CSF-mobilized PBSC. The use of intensification treatment as 'purging in vivo' prior both to collection of PBSC and PBSCT significantly reduces the risk of relapse in this group of patients.

Importance of mixed chimerism to predict relapse in persistently BCR/ABL positive long survivors after allogeneic bone marrow transplantation for chronic myeloid leukemia

Determination of hematological chimerism could be helpful in understanding the biology of leukemic relapse after allogeneic bone marrow transplant (BMT) for chronic myeloid leukemia (CML), because the detection of malignant residual cells carrying the bcr/abl message by qualitative RT-PCR is of limited value in predicting disease progression for individual patients. We have studied the chimerism pattern and the bcr/abl status by Southern-blot in 15 CML patients (M/F:6/9) transplanted with unmanipulated BM from HLA identical sibling donors, persistently bcr/abl positive by RT-PCR. The median age of the series was 31 years (18-49) and disease status at BMT was: chronic phase: 11, accelerated phase: 3 and blast crisis: 1 patient. Of the 15 patients, 9 are alive and in complete remission (CR), 4 have died in CR and 2 are alive but suffered relapse at + 19 and +26 months post-BMT. The median follow-up is 81 months (13,7-168). Rearrangement of the BCR gene was performed by Southern-blot using P32-labeled transprobe-1. PCR analysis of chimerism was assessed using primers for the following VNTR loci: D1S80, D1S111, 33.1, APO-B, YNZ-22, lambdag3 and DXS52. Seventy-nine samples were analyzed (median per patient 5 (range 2-9)). Thirteen patients showed complete chimerism and lacked BCR rearrangement over time by Southern-blot. The 2 patients who relapsed showed mixed chimera status from +9 and +5 months respectively until the end of the study. Persistent BCR rearrangement was observed in these 2 patients from +12 and +11 months respectively. Our data suggest that mixed chimerism may predict hematologic or cytogenetic relapse by several months in those patients who are persistently PCR-positive post-BMT.

Allele-specific PCR method based on pncA and oxyR sequences for distinguishing Mycobacterium bovis from Mycobacterium tuberculosis: intraspecific M. bovis pncA sequence polymorphism

An allele-specific amplification method based on two genetic polymorphisms to differentiate Mycobacterium tuberculosis from Mycobacterium bovis was tested. Based on the differences found at position 169 in the pncA genes from M. tuberculosis and M. bovis, a PCR system which was able to differentiate most of the 237 M. tuberculosis complex isolates tested in one of the two species was developed. All 121 M. tuberculosis strains showed the expected base (cytosine) at position 169. Most of the M. bovis isolates had a guanine at the cited position. Nevertheless, 18 of the 116 M. bovis isolates, all of them goat isolates, showed the pncA polymorphism specific to M. tuberculosis. These results suggest that goat M. bovis may be the nicotinamidase-missing link at the origin of the M. tuberculosis species. Based on the polymorphism found at position 285 in the oxyR gene, the same system was used to differentiate M. tuberculosis from M. bovis. In this case, DNAs from all 121 M. tuberculosis isolates had the expected base (guanine) at this position. In addition, all 116 M. bovis isolates, including those from goats, showed the identical polymorphism (adenine). The oxyR allele-specific amplification method can differentiate M. bovis from M. tuberculosis, is rapid (results can be obtained in less than 3 h), and is easy to perform.

Identification by spoligotyping of a caprine genotype in Mycobacterium bovis strains causing human tuberculosis

We have used spoligotyping to characterize 18 Mycobacterium bovis strains isolated from cattle and 23 M. bovis strains isolated from goats. The spoligotypes revealed that caprine strains form a separate and well-differentiated group that we refer to hereafter in this abstract as the caprine genotype. To evaluate the importance of this genotype as a cause of tuberculosis in other animal species, including humans, we applied the spoligotyping method to 112 strains, including to all isolates identified as M. bovis by a Mycobacterial National Reference Laboratory (Majadahonda, Madrid) from 1994 to 1996. Eighty-three of these strains were identified in human isolates. In addition to being identified in three goat isolates and two sheep isolates, the caprine genotype was also found in three isolates causing human tuberculosis. Evidence to support the argument that there is a zoonotic risk of caprine tuberculosis was presented by the identification of the caprine genotype in an isolate from a veterinary worker with a recent history of contact with tuberculous goats.

[Positron emission tomography detection of residual disease in a case of lung cancer]

To date, computed tomography is considered the best procedure to detect either relapse or residual disease in non-small cell lung cancer. However, in recent years several studies have stressed the value of F-18 fluorodeoxyglucose positron emission tomography (FDG PET) which takes advantage of the enhanced glucose uptake observed in neoplastic cells. We present the case of a patient with a locally advanced non-small cell lung cancer who received trimodal treatment with induction chemotherapy followed by surgical resection and postoperative irradiation and lately developed brain metastases which were treated with chemoradiotherapy plus radiosurgery. However a small residual lesion remained in the brain magnetic resonance. Such abnormality was evaluated by means of FDG PET which did not show any increase on FDG uptake. The present case prompt us to review the role of FDG PET as a procedure that enable to detect subclinical disease and its potential usefulness taking into account the improvement in management strategies that has been attained in non-small cell lung cancer.

Brucellar prosthetic arthritis in a total knee replacement

The infecting pathogens most commonly implicated in prosthetic joint infections are staphylococci, streptococci, and gram-negative rods. Prosthetic infections caused by Brucella spp. are rarely described in the literature. Treatment of prosthetic infections remains complex and controversial, the most accepted course being antibiotic treatment with removal or retention of prosthetic components. The case of a 60-year-old man who developed Brucella septic arthritis of the right knee in a total knee replacement is reported. Conservative treatment using a three-drug therapy was employed, with excellent results.

katGI and katGII encode two different catalases-peroxidases in Mycobacterium fortuitum

It has been suggested that catalase-peroxidase plays an important role in several aspects of mycobacterial metabolism and is a virulence factor in the main pathogenic mycobacteria. In this investigation, we studied genes encoding for this protein in the fast-growing opportunistic pathogen Mycobacterium fortuitum. Nucleotide sequences of two different catalase-peroxidase genes (katGI and katGII) of M. fortuitum are described. They show only 64% homology at the nucleotide level and 55% identity at the amino acid level, and they are more similar to catalases-peroxidases from different bacteria, including mycobacteria, than to each other. Both proteins were found to be expressed in actively growing M. fortuitum, and both could also be expressed when transformed into Escherichia coli and M. aurum. We detected the presence of a copy of IS6100 in the neighboring region of a katG gene in the M. fortuitum strain in which this element was identified (strain FC1). The influence of each katG gene on isoniazid (isonicotinic acid hydrazide; INH) susceptibility of mycobacteria was checked by using the INH-sensitive M. aurum as the host. Resistance to INH was induced when katGI was transformed into INH-sensitive M. aurum, suggesting that this enzyme contributes to the natural resistance of M. fortuitum to the drug. This is the first report showing two different genes encoding same enzyme activity which are actively expressed within the same mycobacterial strain.

Long-term follow-up of immunosuppressive treatment for obstructive airways disease after allogeneic bone marrow transplantation

To describe clinical outcome with first line immunosuppression therapy for obstructive airways disease (OAD) after allogeneic BMT, we have retrospectively examined 20 long-term survivors affected by OAD. All patients had normal pulmonary function test (PFTs) before BMT. OAD was defined as FEV1 less than 80%, FER less than 80%, maximum midexpiratory flow rate of 50% vital capacity (MMFR) less than 65%, or residual volume greater than 120. Prednisone (n = 4), CsA (n = 8) and azathioprine (n = 8) have been used as first-line immunosuppression agents. Mean follow-up was 65 months (range 15-142). We identified three categories of patients according to response to treatment: complete (n = 6, 30%), partial (n = 6, 30%) or no response (n = 8, 40%). Age, FEV1, time of onset after BMT, Karnofsky index or immunosuppression modality do not seem to be related to subsequent response. However, patients with low values of MMFR and high values of RV at the beginning of therapy are likely to show poor response. In the complete response group, normalisation of PFTs is achieved within the first months of treatment (median 6 months ranging from 3 to 9 months), suggesting that prolonged therapy is not advantageous and could increase morbidity and mortality if there are no other signs of CGVHD.

Neuronal nitric oxide synthase activation by vasoactive intestinal peptide in bovine cerebral arteries

The participation of nitric oxide and vasoactive intestinal peptide (VIP) in the neurogenic regulation of bovine cerebral arteries was investigated. Nitrergic nerve fibers and ganglion-like groups of neurons were revealed by NADPH-diaphorase staining in the adventitial layer of bovine cerebral arteries. NADPH diaphorase also was present in endothelial cells but not in the smooth muscle layer. Double immunolabeling for neuronal nitric oxide synthase and VIP indicated that both molecules co-localized in the same nerve fibers in these vessels. Transmural nerve stimulation (200 mA, 0.2 milliseconds, 1 to 8 Hz) of endothelium-denuded bovine cerebral artery rings precontracted with prostaglandin F2 alpha, produced tetrodotoxin-sensitive relaxations that were completely suppressed by NG-nitro-L-arginine methyl ester (L-NAME) and by the guanylyl cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline (ODQ), but were not affected by the adenylyl cyclase inhibitor 9-(tetrahydro-2-furanyl)-9H-purin-6-amine (SQ 22,536), nor by VIP tachyphylaxis induced by pretreatment with 1 mumol/L VIP. Transmural nerve stimulation also elicited increases in intracellular cyclic GMP concentration, which were prevented by L-NAME, and small decreases in intracellular cyclic AMP concentration. Addition of VIP to bovine cerebral artery rings without endothelium produced a concentration-dependent relaxation that was partially inhibited by L-NAME, ODQ, and SQ 22,536. The effects of L-NAME and SQ 22,536 were additive. VIP induced a transient increase in intracellular cyclic GMP concentration, which was maximal 1 minute after VIP addition, when the highest relaxation rate was observed, and which was blocked by L-NAME. It is concluded that nitric oxide produced by perivascular neurons and nerve fibers fully accounts for the experimental neurogenic relaxation of bovine cerebral arteries and that VIP, which also is present in the same perivascular fibers, acts as a neuromodulator by activating neuronal nitric oxide synthase.

A preliminary report of a phase II trial. UFT plus oral folinic acid as therapy for metastatic colorectal cancer in older patients. Spanish Group for the Treatment of Gastrointestinal Tumors (TTd Group)

The oral fluoropyrimidines have proved to be active in colorectal cancer in Japan and, recently, in the United States and Europe. Continuous oral administration simulates protracted fluorouracil (5-FU) continuous intravenous infusion. The purpose of this trial was to evaluate the tolerability and potential advantages of oral treatment for colorectal cancer in the elderly. The main inclusion criterion was age over 72 years. Patients were treated with UFT (tegafur plus uracil) 400 mg/24 hours (fixed doses) continuously plus folinic acid 45 mg/24 hours until toxicity. If grade 3 or 4 toxicity appeared, treatment was stopped until recovery. From September 1994 to November 1996, 126 patients were included. For the analysis in November 1996, 77 patients were evaluable for response, toxicity, and survival. The patients, including 34 women and 43 men, had a median age of 74 years (range, 72 to 82 years of age). The Karnofsky performance status was 60% to 80% for 41 patients and 90% to 100% for 36 patients. Liver metastasis was present in 48% of the cases, and 42% were locoregional and peritoneal. Toxicity was mild, with only one patient having grade 3 thrombocytopenia, 11 (14%) grade 3 or 4 nausea/vomiting, seven (9%) grade 3 or 4 diarrhea, and one grade 3 mucositis. Four patients (5%) had complete responses and nine (11.6%) partial responses, for an objective response rate of 16.9% (95% confidence interval, 9% to 27%). Twenty-two patients (28.6%) showed no change. The number of patients in whom disease did not progress (ie, patients with complete plus partial responses plus those with stable disease) was 35 (45.4%) (95% confidence interval, 34% to 57%). With a maximum follow-up of 24 months, the median actuarial survival is 14.4 months. The number without disease progression and the median survival in this preliminary analysis suggests that this schedule is a moderately effective, comfortable, treatment with only mild toxicity, that can be recommended for use in the elderly, and it warrants further study.

Transmission between HIV-infected patients of multidrug-resistant tuberculosis caused by Mycobacterium bovis

OBJECTIVE

To investigate outbreaks of multidrug-resistant tuberculosis (TB) by using DNA fingerprint databases.

DESIGN

Investigation of two outbreaks of multidrug-resistant TB in separate hospitals in Spain by restriction fragment length polymorphism (RFLP) and spoligotyping. Outbreak strains were compared with more than 1500 RFLPs of Mycobacterium tuberculosis complex strains isolated in Spain and 6000 RFLPs from 30 different countries.

METHODS

Standardized IS6110 DNA fingerprinting and 'spoligotyping' was used to type multidrug-resistant isolates belonging to the M. tuberculosis complex amongst the outbreak cases. The DNA types were matched against DNA fingerprint databases in Spain and The Netherlands.

RESULTS

The DNA typing analysis indicated that a single multidrug-resistant Mycobacterium bovis strain was responsible for a nosocomial outbreak in a hospital in Spain involving at least 16 HIV-infected patients with non-treatable to multidrug-resistant TB. Introduction of the fingerprint type of this strain to the international database revealed a single matching strain. This strain was also isolated from an HIV-infected patient in The Netherlands who had died from multidrug-resistant TB. This patient had previously been hospitalized in Spain, where a multidrug-resistant TB nosocomial outbreak involving 20 HIV-infected patients was ongoing. The strains causing this outbreak were also identified as M. bovis with an identical DNA pattern to those strains isolated in the Spanish hospital and the patient in The Netherlands.

CONCLUSIONS

The use of centralized DNA databases can help to identify rapidly the origin and transmission routes of multidrug-resistant TB across international boundaries and the potential use of such an early warning surveillance system for investigation of nosocomial multidrug-resistant TB outbreaks between HIV-infected patients. To our knowledge this is the first report of transmission of multidrug-resistant M. bovis between hospitals.

Isolation by genetic labeling of a new mycobacterial plasmid, pJAZ38, from Mycobacterium fortuitum

In a two-step mating experiment with recipient strains of Mycobacterium smegmatis, the Mycobacterium fortuitum cryptic plasmid pJAZ38 was isolated. Plasmid pJAZ38 was genetically labeled by cointegration formation mediated by the kanamycin-resistant mycobacterial transposon Tn611. The region responsible for replication of pJAZ38 was located and sequenced. This region showed homology with the Mycobacterium avium plasmid pLR7 and the Mycobacterium scrofulaceum plasmid pMSC262, a family of plasmids which have been found to be widespread throughout the mycobacteria. Further experiments showed pJAZ38 to be stably inherited in the absence of selection pressure and compatible with the most commonly used mycobacterial replicon, pAL5000. In contrast to pLR7 and pMSC262, pJAZ38 was able to replicate in M. smegmatis mc(2)155, making it a useful tool for mycobacterial genetics.

Antioxidant action of estrogens in rat hepatocytes

The in vitro addition of 17 beta-estradiol (0-100 microM) to isolated rat hepatocytes efficiently prevented cellular lipid oxidation induced by the Fe(III)/ADP complex. 17 beta-estradiol was found to be less effective than its metabolic derivative 2-hydroxyestradiol. The presence of specific inhibitors of cytochrome P450 activity significantly diminished the antioxidant capacity of estradiol. These observations support the hypothesis that estradiol, in the micromolar range, inhibits iron-induced lipid peroxidation in liver cells by diverting reducing equivalents from the peroxidative process to its own metabolism.