Prevalence of Chlamydia trachomatis infection in registered female sex workers in northern Mexico

BACKGROUND: Little is known about the epidemiology of Chlamydia trachomatis infection in female sex workers (FSWs) in Mexico. GOAL: The goal of the study was to determine the prevalence of C trachomatis infection in registered FSWs from northern Mexico and to determine the sociodemographic characteristics associated with the infection. STUDY DESIGN: An enzyme immunoassay was used to test 354 FSWs in three northern Mexican cities for cervical C trachomatis infection. All participants were registered in a government health office. Recruitment was consecutive and voluntary. The association between clinical and sociodemographic characteristics of FSWs and infection was evaluated. RESULTS: The overall prevalence of C trachomatis infection among participants in the three cities was 12.4%. Women of low socioeconomic level and those younger than 25 years were the most frequently infected. Among FSWs in Durango, a higher frequency of C trachomatis infection was found for those who did not use condoms. CONCLUSION: C trachomatis is an important pathogen in the sexually transmitted diseases of registered FSWs in northern Mexico.     

Object and spatial relational memory in adult rhesus monkeys is impaired by neonatal lesions of the hippocampal formation but not the amygdaloid complex

Adult rhesus monkeys with neonatal aspiration lesions of the hippocampal formation or the amygdaloid complex (including their respective subjacent cortices) and their age-matched controls were tested on the transverse patterning problem (A+ vs. B-, B+ vs. C- and C+ vs. A-) and a spatial version of the delayed nonmatching-to-sample (DNMS) task with delays of 10 s to 30 s, 60 s, 120 s, and 600 s. Monkeys with neonatal damage to the amygdaloid complex learned both tasks and did not differ from controls at any delay of the spatial DNMS task. Monkeys with neonatal hippocampal damage, however, were unable to learn transverse patterning, though they easily transferred to a linear series (A+ vs. B-, B+ vs. C-, and C+ vs. X-). Three of the four were also unable to reach criterion on the spatial DNMS task within the limits of testing, and the performance of all four monkeys deteriorated with increasing choice delays. The data suggest a role of the primate hippocampal region in both object and spatial relational learning.     

Evolving role of ribonucleoside reductase inhibitors in hematologic malignancies

Ribonucleotide reductases catalyze the de novo biosynthesis of deoxyribonucleosides for DNA synthesis. Increased ribonucleotide reductases activity has been associated with malignant transformation and tumor cell growth. The ribonucleotide reductases inhibitors may bind with the R1 subunit of the enzyme (Class 1) or the nonheme iron (Class 2). This review focuses on the therapeutic use of ribonucleotide reductases inhibitors in hematologic malignancies. Hydroxyurea, fludarabine and cladribine have established roles in the management of hematologic malignancies, while other ribonucleotide reductases inhibitors, such as gemcitabine, tezacitabine and heterocyclic carboxaldehyde thiosemicarbazones (e.g., triapine) are being evaluated in clinical trials.     

Assessment of locus and extent of neurotoxic lesions in monkeys using neuroimaging techniques: a replication

Foot-shock is used in a variety of behavioral tasks either as a motivational stimulus, a way to characterize different rodents, or to test various pharmacological agents for their antinociceptive or analgesic effects. All these procedures need to assess foot-shock sensitivity either to rule out possible differences (when the shock is used as a motivational stimulus) or to use the differences to compare animals or treatments. In addition, many of the procedures that utilize foot-shock as a motivational stimulus evaluate freezing as an index of anxiety or fear. In the present study, data obtained by an automated computer system was compared with data obtained by human observers to validate the automated system for examining foot-shock sensitivity in mice. The different computer measures obtained for foot-shock sensitivity exhibited high correlations with human scoring at shock levels as low as 0.2 mA. The computer controlled analysis provided a non-subjective, quantifiable measurement of the foot-shock-induced response as well as freezing behavior. Automated data collection is an improvement over the methods of human visual observation in that the data collection is more standardized, efficient and consistent.     

Specific c-K-ras Gene Mutations as a Tumor-Response Marker in Locally Advanced Rectal Cancer Treated With Preoperative Chemoradiotherapy

Background: Forty percent of patients with colorectal cancer develop mutations in the K-ras gene.Objective: Our objective was to evaluate whether the presence of c-K-ras gene mutations is a useful tumor-response marker in patients with locally advanced rectal cancer treated with preoperative chemoradiotherapy.Material and Methods: Thirty seven patients with locally advanced rectal cancer were treated with preoperative chemoradiotherapy. Four to six weeks later, surgery was performed. Specimens were classified according to the UICC-AJC classification. A segment of the tumor was obtained to analyze specific c-K-ras gene mutations. Restriction fragment length polymorphism (RFLP) and single strand confirmation polymorphism (SSCP) techniques were used with a set of probes to detect specific c-K-ras mutations in codons 12, 13, and 61. The 37 patients were divided into Group A (with mutations) and Group B (without mutations).Results: All 37 patients completed the scheduled treatment. Group A consisted of 12 patients, whose tumors were classified and specific c-K-ras mutations were located as follows: eight in codon 12, two in codon 13, and one in codon 61. Group B consisted of 25 patients. The tumors were classified and there were more early-stage tumors in Group A, whereas in Group B there were more advanced-stage tumors (P 5 .05, respectively). The mean follow-up was 36.2 6 18.3 months. All Group A patients survived, whereas 8 of the 25 patients in Group B died due to progressive metastatic disease. Survival in Group A was 100%, whereas in Group B it was 59% (P 5 .03).Conclusions: The presence of specific c-K-ras mutations is an indicator of tumor response in patients with locally advanced rectal cancer treated with preoperative chemoradiotherapy and surgery. Therefore, responding patients may be more amenable to less radical surgical procedures based on c-K-ras mutations.     

Multidrug resistance-1 (MDR-1) in rheumatic autoimmune disorders. Part I: Increased P-glycoprotein activity in lymphocytes from rheumatoid arthritis patients might influence disease outcome

BACKGROUND: Multidrug resistance (MDR) is characterized by overexpression of P-glycoprotein, a pump molecule that decreases intracellular drug concentrations by increasing drug efflux from cells. OBJECTIVE: To look for correlations between clinical status and P-glycoprotein activity and/or TNF-alpha mRNA levels in patients with rheumatoid arthritis. METHODS: Sixteen patients were studied. Based on response to therapy, eight were refractory and eight nonrefractory to treatment. Findings were compared to those in 24 healthy controls. Flow cytometry was used to evaluate P-glycoprotein activity in peripheral blood mononuclear cells isolated by gradient centrifugation and incubated with the P-glycoprotein substrate daunorubicin. TNF-alpha mRNA levels were determined using quantitative PCR. RESULTS: Patients with rheumatoid arthritis showed an increased number of lymphocytes with high P-glycoprotein activity (p = 0.0001) as compared to the normal controls. P-glycoprotein activity was higher in the refractory than in the non-refractory patient subgroup (p = 0.006). Also, TNF-alpha mRNA levels were markedly higher in the refractory subgroup than in the nonrefractory subgroup, and were undetectable in the normal controls. CONCLUSIONS: Enhanced P-glycoprotein activity may be closely related to an unfavorable clinical course and a poor response to treatment. Increased TNF-alpha expression and chronic exposure to various drugs, including glucocorticoids, may contribute to increase P-glycoprotein activity. Both high P-glycoprotein activity and excessive amounts of TNF-alpha seem associated with poor outcome in rheumatoid arthritis.     

Death caused by perioperative fasting and sedation in a child with unrecognized very long chain acyl-coenzyme A dehydrogenase deficiency

An adopted 3(1/2)-year-old girl with no prior medical problems died after a routine dental procedure. More than 2 years later, acylcarnitine analysis of dried blood found on her bedding revealed she had very long chain acyl-coenzyme A dehydrogenase (VLCAD) deficiency. Perioperative oral fasting, without intravenous administration of glucose, may be detrimental to children with certain metabolic and endocrine disorders. Newborn screening by tandem mass spectrometry will detect disorders of fatty acid oxidation such as VLCAD and allow early and preventive treatment.     

Second lethal events associated with treatment for Hodgkin's disease: a review of 2980 patients treated in a single Mexican institute

Presence of second neoplasms and cardiac toxicity has been recognized as potential late lethal second events in patients treated for Hodgkin's disease. However, most reports analyze these association independently. We reviewed 2980 cases of patients treated during 1970-1995 with long-term follow-up (> 4 years) in an attempt to identify all late events in Hodgkin's disease secondary to the treatment or those which are unrelated. Three hundred and ten patients died, and of these 156 were secondary to relapse and tumor progression. Death associated second tumors and cardiac events were increased 37 fold and 29 fold respectively compared to the general population. The risk factors for this complications did not differ to previous reports and included alkylating agents and/or radiotherapy for second neoplasms and anthracycline therapy and radiotherapy for cardiac toxicity. Moreover, 61 patients died secondary to non-related events. Nevertheless, at 20-years overall survival was 90 % (95 % confidence interval (CI): 78 % to 97 %) and event free survival was 88 % (95 % CI: 76 % to 96 %) for these patients. Thus, second events, fatal in most cases, should be considered as an expected risk to the treatment in patients with Hodgkin's disease; the proposed modifications of therapy may indeed be useful to avoid or diminish these complications in the future.