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Biomedical subjects

L Guzmán

Publications and source records attributed to L Guzmán.

At least 19 recordsLinked to original sources
PubMed2001

HCV genotype analysis in HCV-HIV-co-infected Puerto Ricans who are injecting drug users: undetermined and mixed infections.

Direct percutaneous exposure is the main route of HCV transmission. In Puerto Rico half of people infected with HIV use illicit drugs. The effects of HCV in the course of HIV infection and vice versa have been extensively studied, but remain highly controversial. This may be due to HCV genetic heterogeneity. Therefore, a complex classification into genotypes has emerged that prompted us to determined how this impacts a population of intravenous drug users (IDUs) co-infected with HIV-1. Using Inno-LiPa II technique, we analyzed samples from 171 HCV-HIV-1-co-infected IDUs and 375 from a general HCV population of unknown HIV or source of infection status. Similar HCV genotype distribution was detected in these populations. HCV genotype 1a was the most frequently in IDUs-co-infected with HIV-1, followed by 1b and 3a. Twenty mixed infections and 5 undetermined genotypes were reported. A reduced HCV viral load was observed in HIV-1 positives with wasting syndrome. Individuals with a high HIV-1 viral load presented a low HCV viral load. There were no correlation between HCV genotypes and AIDS-related event. Patients with genotype 1b showed a higher HCV viral load. Males presented higher HCV viral load than females. Females were predominantly affected by genotype 1a, and men by 1a and 1b. Neither the HCV viral load nor the frequency of genotypes were influenced by the antiretroviral modality. The importance of continuous genotype monitoring is stressed.

Adult↗
PubMed2000

Role of tfdC(I)D(I)E(I)F(I) and tfdD(II)C(II)E(II)F(II) gene modules in catabolism of 3-chlorobenzoate by Ralstonia eutropha JMP134(pJP4).

The enzymes chlorocatechol-1,2-dioxygenase, chloromuconate cycloisomerase, dienelactone hydrolase, and maleylacetate reductase allow Ralstonia eutropha JMP134(pJP4) to degrade chlorocatechols formed during growth in 2,4-dichlorophenoxyacetate or 3-chlorobenzoate (3-CB). There are two gene modules located in plasmid pJP4, tfdC(I)D(I)E(I)F(I) (module I) and tfdD(II)C(II)E(II)F(II) (module II), putatively encoding these enzymes. To assess the role of both tfd modules in the degradation of chloroaromatics, each module was cloned into the medium-copy-number plasmid vector pBBR1MCS-2 under the control of the tfdR regulatory gene. These constructs were introduced into R. eutropha JMP222 (a JMP134 derivative lacking pJP4) and Pseudomonas putida KT2442, two strains able to transform 3-CB into chlorocatechols. Specific activities in cell extracts of chlorocatechol-1,2-dioxygenase (tfdC), chloromuconate cycloisomerase (tfdD), and dienelactone hydrolase (tfdE) were 2 to 50 times higher for microorganisms containing module I compared to those containing module II. In contrast, a significantly (50-fold) higher activity of maleylacetate reductase (tfdF) was observed in cell extracts of microorganisms containing module II compared to module I. The R. eutropha JMP222 derivative containing tfdR-tfdC(I)D(I)E(I)F(I) grew four times faster in liquid cultures with 3-CB as a sole carbon and energy source than in cultures containing tfdR-tfdD(II)C(II)E(II)F(II). In the case of P. putida KT2442, only the derivative containing module I was able to grow in liquid cultures of 3-CB. These results indicate that efficient degradation of 3-CB by R. eutropha JMP134(pJP4) requires the two tfd modules such that TfdCDE is likely supplied primarily by module I, while TfdF is likely supplied by module II.

Bacterial Proteins↗
PubMed1998

The C2 cytosolic loop of adenylyl cyclase interacts with the activated form of G alpha s.

Using the yeast two-hybrid system, we studied the physical interaction between the complete C1 and C2 cytosolic domains of Xenopus laevis type 9 (xl9C1, xl9C2) and the C2 domain of rat type 6 (r6C2) adenylyl cyclase (AC). Heterodimerization between xl9C1 and xl9C2 and homodimerization between C2 (but not C1) domains was observed. Interaction between C2 and human G alpha s (hG alpha s) was also detected and was dependent on G alpha s activation. In contrast X. laevis G alpha s (xlG alpha s), which is 92% identical to hG alpha s, was unable to interact with any of the three AC cytosolic domains tested, corroborating previous findings that showed no effector activation. Through the construction of chimeras, we demonstrated that the amino-terminal half of xlG alpha s was responsible for the lack of interaction with AC. Chimeras between mouse G alpha i2 and G alpha s (N-mG alpha i2/C-G alpha s), that have previously shown to activate AC to a higher extent than wild-type G alpha s, also interacted with the C2 cytosolic domain and with a higher affinity. Interestingly, N-mG alpha i2/C-xlG alpha s chimera was not only able to interact with C2 but also with the C1 cytosolic domain.

Adenylyl Cyclases↗
PubMed1996

[Lyme disease in Chile. Prevalence study in selected groups].

BACKGROUND: The prevalence of Lyme disease in Chile is unknown. AIM: To study the existence and epidemiology of Lyme disease in Chile. PATIENTS AND METHODS: One hundred eighteen patients with signs or symptoms suggestive of Lyme disease were studied. Antibodies against Borrelia burgdorferi were measured using ELISA and indirect immunofluorescence screening tests. Positive cases were confirmed with ELISA using a purified antigen and Western Blot analysis. Human biological samples and ticks were cultured in BSK-H medium. RESULTS: Five patients, three with dermatological manifestations and two with facial palsy and other neurological symptoms, had antibodies against Borrelia, measured by ELISA and indirect immunofluorescence. However the presence of IgM antibodies by ELISA using purified antigen, was confirmed in only one case. All sera and cerebrospinal fluids were negative on Western Blot Analysis. No plasma, skin, CSF or thick culture yielded Borrelia CONCLUSIONS: We could not confirm the existence of Lyme disease in Chile. Positive screening with negative confirmatory test suggests false positive non-specific reactivity or that local Borrelia are antigenically different compared to North American strains.

Adolescent↗
PubMed1994

[Tenosynovitis caused by ciprofloxacin. Clinical case].

We report a 67 years old diabetic female that received ciprofloxacin for an acute pyelonephritis. Twelve days after starting this treatment, a hand and forearm tenosynovitis appeared, that subsided after the discontinuation of ciprofloxacin. Literature review disclosed other reports of tenosynovitis associated with the use of this antimicrobial.

Aged↗
PubMed1993

[Rapidly progressive kidney failure associated with neutrophil anticytoplasmic autoantibodies. Anatomo-clinical case].

We report a 63 year old woman with a rapidly progressive renal failure and fever of unknown origin. Laboratory tests showed anemia, increased ESR and a urine analysis compatible with a glomerular disease. Antineutrophil cytoplasmic autoantibodies were positive with a perinuclear pattern. Kidney biopsy showed an autoimmune crescenteric glomerulonephritis. The patient had a bad evolution, dying after a massive hemoptysis. The necropsy showed a disseminated arteritis without compromise of bronchial vessels. The oligosymptomatic presentation of this patient, bearing in mind the anatomo-pathological findings, is noteworthy and emphasizes the usefulness of serological markers as antineutrophil cytoplasmic autoantibodies in the differential diagnosis.

Acute Kidney Injury↗
PubMed1993

[Lupus erythematosus disseminatus and Pneumocystis carinii pneumonia].

We report a 49 years old woman with systemic lupus erythematosus and a WHO type IV nephropathy, treated with prednisone 1 mg/kg/day po and cyclophosphamide 1 g/month iv. After two months in this treatment schedule, she presented with an acute pneumonia; broncoalveolar lavage and lung biopsy disclosed the presence of Pneumocystis carinii. She was treated with trimethoprim-sulfamethoxazole 960 mg tid with a favorable response. Opportunistic infections are frequent in lupus erythematosus and Pneumocystis carinii pneumonia has been recently reported in this disease. The changes in immune response and the adverse effects of drugs used in its treatment may explain the increased susceptibility of these patients to infections by Pneumocystis carinii.

Bronchoalveolar Lavage Fluid↗
PubMed1993

[New perspectives in the treatment of rheumatoid arthritis].

The medical treatment of Rheumatoid Arthritis (RA), is currently going through deep changes, stimulated by the findings that the usual sequential fashion of administering different drugs does not stop the course of the disease and that erosions develop even in the first year. Combination therapy, including immunosuppressants, are advocated early in the course of RA. The use of potent and potentially dangerous drugs should be given to the patients who are more likely to develop a more severe disease. Clinical and laboratory markers of severity might guide the treatment of these patients.

Anti-Inflammatory Agents↗
PubMed1992

[Polymorphic reticulosis: a type of lymphoma? Report of 3 cases].

Three patients seen at the Medicine Department of Del Salvador Hospital between 1986 and 1990 are reported. All had a history of purulent or bloody nasal discharge and recurrent sinusitis, before the appearance of progressive and painful destructive phenomena that affected the rhino faucial region. The diagnosis was made with the histopathological study that disclosed and angiocentric polymorphic infiltrates and perivascular necrosis. The three patients received similar treatment consistent in prednisone 1 mg/kg/day per os, cyclophosphamide 2 mg/kg/day per os and local radiotherapy. The response to therapy was bad and survival was less than three months. It is concluded that although this entity is infrequent, its severity requires and aggressive workup and management by a multidisciplinary team. Notwithstanding the mortality remains to be high.

Adult↗
PubMed1992

[Anticardiolipin antibodies in connective tissue diseases].

The incidence of anticardiolipin (ACL) antibodies in connective tissue disorders other than systemic lupus was investigated in 113 subjects: 68 had rheumatoid arthritis, 23 primary Sjogren syndrome and 22 had systemic sclerosis. VDRL, thromboplastin time and determination of IgG and IgM ACL antibodies (ELISA) were performed in all subjects. Overall, 45% of patients were positive for ACL antibodies, mostly of the IgG variety (90%). No differences were observed among the investigated diseases. Positive ACL antibodies were not related to evidence of antiphospholipid syndrome nor to clinical characteristics of the different diseases. These results confirm that ACL antibodies may be present in connective tissue disorders other than systemic lupus, but they do not predict the development of antiphospholipid syndrome nor help to characterize the severity of the disease.

Antibodies, Anticardiolipin↗
PubMed1991

[Severe ischemia of the hand. Treatment with regional intravenous sympathicolysis with reserpine].

Treatment of severe hand ischemia a associated to progressive systemic sclerosis and other disorders is controversial. We studied prospectively 45 patients, 41 female and 4 males, over an 11 year period. Age ranged from 16 to 73 years, mean 46. Underlying disease was systemic sclerosis in 30, CREST in 8, overlapping syndrome in 4, systemic lupus in 1 and non rheumatic vasculitis in 2 patients. Treatment consisted of intravenous injection of reserpine, 1 mg, at a superficial arm vein after controlled local circulatory block for 15 min. Regional anesthesia was required in 38 patients. Adequate follow up was obtained in 32 females and 2 males, receiving a mean of 3.1 therapy sessions (range 1 to 13). Morphologic improvement from 3.09 +/- 0.16 to 1.57 +/- 0.13 and functional improvement from 3.6 +/- 0.12 to 1.75 +/- 0.14 (5 grade scoring system), was observed (p < 0.001). These results correlate with adequate rehabilitation confirmed clinically.

Adolescent↗
PubMed1991

[Anticardiolipin antibodies in systemic lupus erythematosus: prevalence and clinical associations].

Anti-cardiolipin antibodies have been recently described in patients with systemic lupus erythematosus and other autoimmune disorders. Venous and arterial thrombosis, thrombocytopenia and recurrent abortion have been associated to the presence of these antibodies. Among 161 patients with systemic lupus we found 66% with anticardiolipin antibodies, mostly IgG type. Thrombosis and thrombocytopenia were more frequent in these patients (p < 0.05), especially among those with high titers. No association was found with central nervous system involvement, recurrent abortion, antinuclear or anti-DNA antibodies nor positivity for VDRL. These results support the frequent presence of anti-cardiolipin antibodies in patients with systemic lupus and their association to thrombosis and thrombocytopenia.

Adolescent↗
PubMed1991

[Anticardiolipin antibodies and primary antiphospholipid syndrome of the central nervous system: report of 10 clinical cases].

An association between anti-phospholipid antibodies and different disorders of the central nervous system has been described recently. We used an ELISA technique and detected anti-cardiolipin antibodies of the IgG or IgM variety in a series of 10 patients: 4 had occlusive stroke, 2 brain hemorrhage, 2 chorea, 1 a Sneddon syndrome and 1 vascular cephalea. The diagnosis of primary anti-phospholipid syndrome was suggested after ruling out systemic lupus in all patients.

Adult↗
PubMed1990

[Sacroiliac infection: clinical characteristics in 11 cases].

We report clinical and laboratory findings in 11 patients with septic sacro-iliitis. Fever, pain and immobility were prominent symptoms. Acute tenderness of the sacroiliac joint and elevation of the ESR were present in all. Joint puncture allowed identification of the infectious agent in 10 patients: S aureus 4, S typhi 3, E coli 2 and P mirabilis 1. Good clinical results were obtained after appropriate antibiotic therapy.

Adolescent↗