El cultivo celular en la investigación básica del cáncer de mama

Resumen La técnica del cultivo celular es la que ha permitido conocer el comportamientoin vitro de las células cancerosas. En esta revisión pretendemos introducir las peculiaridades básicas del cultivo celular, referido especialmente a líneas cancerosas mamarias, relacionar el origen de las líneas celulares más utilizadas en la investigación de este cáncer, mencionar las técnicas de laboratorio que pueden aplicarse sobre estos cultivos y ejemplificar la utilidad de las mismas, tomando como modelo diversos trabajos que estudian los efectos del factor de crecimiento epidérmico sobre líneas celulares hormonoindependientes de cáncer de mama.      

Helicobacter pylori erradication and its relation to antibiotic resistance and CYP2C19 status]

OBJECTIVE: to assess the efficacy of rabeprazole (RPZ), amoxicillin (Am), and clarithromycin (Cla) (7 vs. 14 days) in the eradication of H. pylori, and to determine the effect of strain-specific antibiotic resistance and host CYP2C19 status. MATERIAL AND METHODS: first, we determined the CYP2C19 status of 100 healthy subjects to establish a sample size for the clinical trial. Then, 59 H. pylori-infected patients were randomized to receive RPZ (20 mg daily) plus Cla (500 mg b.d.) and Am (1,000 mg b.d.) for 7 vs. 14 days. The MIC for Am and Cla were determined using the agar dilution method. The CYP2C19 genotype was determined by the PCR-RFLP method. RESULTS: In the per-protocol analysis (PP) eradication rates were 89.7 and 72% for the 7- and 14-day groups (p = 0.159). In the intention to-treat analysis (ITT) eradication rates were 86.7 and 62.1% in the 7- and 14-day groups, respectively (p = 0.06).None of the strains was resistant to Am, and 4 strains were resistant to Cla: 3 (11.1%) in the 14-day group and 1 (4%) in the 7-day group. Neither strain-specific antibiotic resistance nor host CYP2C19 status influenced eradication rates. CONCLUSIONS: both 7- and 14-day therapies were effective for H. pylori eradication. Strain resistance and CYP2C19 status do not seem to influence eradication rates in the studied population.     

Experience in the management of myelomeningocele in Puerto Rico

The medical records of 128 children with myelomeningocele who were treated at the Pediatric University Hospital, Puerto Rico Medical Center, from January, 1980, to July, 1985, were reviewed retrospectively. The medical and surgical management during the first hospitalization of these children was studied in detail for predefined parameters. The average age at the time of myelomeningocele repair was 6.6 days. Statistical analysis showed that repair of the myelomeningocele defect before 48 hours of age did not reduce the occurrence of ventriculitis. The incidence of ventriculitis secondary to the management of the myelomeningocele lesion was 12.5%. Complications after repair of the myelomeningocele (including skin flap necrosis, cerebrospinal fluid leaks, and wound infection) were present in 43.8% of the patients who developed ventriculitis and in 19.0% of those who did not. This observation is statistically significant (p = 0.03) and indicates that complications of healing after myelomeningocele repair represent the most significant risk factor for the development of ventriculitis.     

Decrease in penbutolol central response as a cause of changes in its serum protein binding

Penbutolol is a beta-adrenoceptor antagonist that is extensively bound to alpha 1-acid glycoprotein (alpha 1-AGP), a protein that increases in inflammatory diseases thereby binding more drug in such conditions. Changes in serum binding can lead to modifications in the pharmacokinetics and pharmacodynamics of a drug, therefore, the central effect (as the anticonvulsant response) and brain uptake of penbutolol given intravenously to mice with experimental inflammation have been measured. A significant decrease of the central effect of penbutolol and its brain uptake was seen in diseased when compared with control animals (P less than 0.01). A parallel decrease in free fraction of penbutolol in diseased vs normal animals was detected. These results suggest that there is an increase in serum binding of basic drugs related to increments in alpha 1-AGP concentration, which reduces their central pharmacological effect.     

Contribution to the knowledge of Hysterothylacium aduncum through electrophoresis of the enzymes glucose phosphate isomerase and phosphoglucomutase

A total of 163 Hysterothylacium aduncum specimens, obtained from two gadoids and one percid, were studied by electrophoresis of the enzymes glucose phosphate isomerase and phosphoglucomutase. The two loci deviated significantly from the Hardy-Weinberg equilibrium, both when considering all specimens and when distinguishing the hosts. This could suggest that there is no single species in either case. Received: 16 June 1997 / Accepted: 11 July 1997     

Binding units (BU) and the area under binding isotherms (AUI) new indices of effector-target conjugation

New methods for simplified quantitation of effector-target conjugation have been developed. The binding unit (BU) is defined as the number of target cells required to bind a specified percentage of effector cells. The number of binding units is determined from binding isotherms in which effector conjugate frequencies are measured by holding constant the number of effector cells and by varying the number of target cells. Alternately, a binding unit can be defined as the number of effector cells required to bind a specified percentage of target cells. In this case, BU is computed from binding isotherms in which target conjugate frequencies are measured at different values of effector cells by holding constant the number of target cells. Also, the area under the curve (AUI) of these isotherms is another index that can be used as an overall measure of the binding capacity in an effector-target system. The experimental values of BU and AUI determined from effector and target isotherms agree well with theoretical predictions based on our previously developed binding model (J. Immunol. Methods (1992) 155, 133–147). The relationship between BU and AUI, and procedures to determine these parameters are shown. The value of these indices to express effector-target conjugation quantitatively has been confirmed by determining the values of BU and AUI for the NK-K562 effector-target system.