Decreasing cervical cancer mortality in Mexico: effect of Papanicolaou coverage, birthrate, and the importance of diagnostic validity of cytology

BACKGROUND: The reduction in cervical cancer mortality in developed countries has been attributed to well-organized, population-based prevention and control programs that incorporate screening with the Papanicolaou (Pap) smear. In Mexico, there has been a decrease in cervical cancer mortality, but it is unclear what factors have prompted this reduction. METHODS: Using data from national indicators, we determined the correlation between cervical cancer mortality rates and Pap coverage, birthrate, and gross national product, using a linear regression model. We determined relative risk of dying of cervical cancer according to place of residence (rural/urban, region) using a Poisson model. We also estimated Pap smear coverage using national survey data and evaluated the validity and reproducibility of Pap smear diagnosis. RESULTS: An increase in Pap coverage (beta= -0.069) and a decrease in birthrate (beta=0.054) correlate with decreasing cervical cancer mortality in Mexico. Self-reported Pap smear rates in the last 12 months vary from 27.4% to 48.1%. Women who live in the central (relative risk, 1.04) and especially the southern (relative risk, 1.47) parts of Mexico have a greater relative risk of dying of cervical cancer than those who live in the north. There is a high incidence of false negatives in cervical cytology laboratories in Mexico; the percentage of false negatives varies from 3.33% to 53.13%. CONCLUSIONS: The decrease in cervical cancer mortality observed in Mexico is proportional to increasing Pap coverage and decreasing birthrate. Accreditation of cervical cytology laboratories is needed to improve diagnostic precision.     

Endotracheal metastases from colon adenocarcinoma

Endotracheal metastases (ETM) from non-lung cancer are seldom seen. Their main clinical symptoms are cough, haemoptysis and dyspnoea, although occasionally an incidental finding is made during a bronchoscopy. Breast, colon and kidney adenocarcinoma might be associated with ETM, lung cancer being the most frequent cause. Its finding is associated with advanced disease but survival will depend on the primary origin, patient status and comorbidity. Therefore, treatment should be individual for each patient. In our centre we recommend pre-surgery bronchoscopy to exclude metastatic endotracheal lesions in patients with metastatic colon adenocarcinoma disease, as this might affect the final outcome and therefore management of the disease.     

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.     

Recovery from spinal cord injury: a new transection model in the C57Bl/6 mouse

Spinal cord transections in mammalian animal models lead to loss of motor function. In this study, we show that functional recovery from complete transection of the adult mouse spinal cord can in fact occur without any intervention if dural injury along with displacement of the ends of the cut cord and fibroblastic infiltration is minimized. Underlying this function is the expression of GAP-43 in axonal growth cones, axonal extension and bridging of the injury site indicated by biocytin retrograde tracing and neuronal remodeling of both the white matter and the gray matter. Such studies suggest a new murine model for the study of spinal cord regeneration.     

Establishment and characterization of 7 ovarian carcinoma cell lines and one granulosa tumor cell line: Growth features and cytogenetics

The characteristics of 7 newly established ovarian carcinoma cell lines and one granulosa tumor cell line obtained from tumor samples of 7 patients with varying histology of the primary tumor are reported. The cell lines were isolated from 5 serous carcinomas, a mucinous carcinoma, an endometrioid carcinoma and a granulosa cell tumor. All cell lines were passaged at least 25 times and showed stable growth rates. Colony-forming efficiency varied on plastic from 2 to 57% and in agar from 0.01 to 9.30%. The DNA index of the granulosa tumor cell line was diploid, while the ovarian carcinoma cell lines were all aneuploid. In 2 cell lines polyploidisation occurred during culturing. A thorough cytogenetic analysis of 7 cell lines revealed that the granulosa tumor cell line has only minor cytogenetic abnormalities (+5, 22_q+). In contrast, the epithelial ovarian-cancer cell lines gave very complex karyotypes with numerous markers and structurally rearranged chromosomes. The chromosomes most often in excess were 15 and 20. Structural rearrangements of chromosomes 1, 3, 7 and 11 were prominent in all ovarian cell lines. In addition, we found changes in chromosomes X, 5, 8 and 13 that have rarely been described before.     

Enhancing the frequency of antigen-specific hybridomas

Techniques were developed to enhance the frequency of antigen-specific hybridomas by enriching for antibody precursor or -producing lymphocytes prior to cell fusion. Spleen cells of immunized animals were either (a) cultured in vitro for 3–4 days in the presence of the immunizing antigen or (b) adoptively transferred into X-irradiated syngeneic recipients followed immediately by an in vivo antigen boost 4 days prior to use in cell fusion. There was a 10-fold increase in the percentage of wells which develop antigen-specific, antibody-secreting hybridomas following these treatments. These techniques allow an increased yield of hybridomas with a greatly decreased technical effort.     

Effect of long-term oral administration of green tea extract on weight gain and glucose tolerance in Zucker diabetic (ZDF) rats

There have been some claims that green tea reduces weight and lowers blood glucose in diabetes. Intraperitoneal injections of green tea catechins in diabetic rats have shown beneficial effects. To determine if oral administration of green tea would prevent development of diabetes, young Zucker diabetic rats were dosed with green tea extract containing 50-125 mg/kg of Epigallocatechin gallate (EGCG) starting at 7 weeks of age, before the appearance of excessive weight gain and glucose elevation. While there was a trend toward lower weight gain and average daily glucose, there was no statistically significant difference.     

BMP binding peptide: a BMP-2 enhancing factor deduced from the sequence of native bovine bone morphogenetic protein/non-collagenous protein.

Forty years ago, Marshall Urist described a partially purified extract of demineralized bone matrix which induced the formation of ectopic bone. This substance, bone morphogenetic protein/non-collagenous protein (BMP/NCP), was never purified to homogeneity but other investigators used similar starting materials to clone a number of recombinant BMPs. Urist recognized that his material probably contained the BMPs which had been cloned by others but always contended that it contained another, more potent, bone inducing material which differed significantly in its physical and chemical properties from the known BMPs. We have used Urist's protocol to isolate a protein that has the chemical and physical properties of Urist's "BMP". It is an 18.5 kD fragment of the bone matrix protein, SPP-24. This fragment contains the cystatin-like domain of SPP-24. We have located a 19 amino acid region which is similar to the TGF-beta/BMP-binding region of fetuin, a member of the cystatin family of protease inhibitors. A cyclic peptide, which we call BMP binding peptide (BBP) was generated using this sequence. The peptide avidly bound rhBMP-2 with a KD of 3 x 10(-5) M. When implanted alone in mouse muscle, the peptide frequently induced dystrophic calcification. When implanted with rhBMP-2, the peptide enhanced the osteogenic activity of the recombinant molecule. We hypothesize that Urist's "BMP" was a fragment of SPP-24 which influenced bone induction by binding to bone morphogenetic proteins. BBP may be clinically useful because of its effects on other bone-inducing substances.