Radiofrequency ablation of renal tumors in patients unfi t for surgery. Our experience.

PURPOSE: To evaluate the feasibility and safety of the minimally invasive percutaneous technique radiofrequency ablation (RFA) in patients with small renal cell carcinomas (RCCs) who are unfit for surgery. METHODS: From January 2008 to November 2009, 7 patients (5 males and 2 females, median age 78 years) with small RCCs were treated with RFA. The indications for RFA were either inoperability due to high cardiovascular and pulmonary risk or a high probability of complete renal failure after nephrectomy. Exclusion criteria were tumor size larger than 6 cm and the localization of the tumor within the renal pelvis. RESULTS: All RFAs were technically successful in terms of complete tumor ablation and all procedures could be done under conscious sedation. Complications after RFA included transient rise in plasma creatinine in 2 patients and hydrocalyx at 18 months in one. The mean hospital stay was 3.14 days (range 2-5). CONCLUSION: RFA has limitations such as an uncertain long-term oncological result and need for strict follow up. Physicians must be aware of these limitations and present them clearly to the patients. It is a safe treatment modality that, with longer follow-up, could play a more important role in the care of patients with renal masses due to its potential for decreased morbidity, shorter convalescence, and the ability to avert the higher risk of extirpative surgery in an aging patient population.

Molecular cloning and developmental expression of the major fibrous sheath protein (FS 75) of rat sperm.

The fibrous sheath (FS) is a cytoskeletal structure that encases the axoneme in the principal piece of the spermatozoon tail. In the rat, it is composed of several proteins, of which a 75-kDa polypeptide (FS 75), as estimated by PAGE, is the most prominent. The objectives of this study were to clone and sequence this protein and to characterize its transcriptional and translational origins during spermatogenesis. Initially, we isolated two overlapping cDNA segments that encoded a large part of the FS 75 protein but lacked the initiation codon for translation. Both clones were obtained by screening a rat testicular phagemid cDNA library with an anti-FS 75 polyclonal antibody. An upstream portion of the FS 75 mRNA containing the initiation codon was obtained by polymerase chain reaction with a pair of specific primers. Accounting for the overlap in all segments, 2786 nt of an approximately 3-kb FS 75 mRNA was obtained. The amino acid sequence of the longest possible open reading frame of the rat FS 75 was found to be similar to two previously cloned variants of the major FS polypeptide of mouse spermatozoa. Sequence analysis of the rat FS cDNA revealed anchoring kinase A protein domains and several kinase phosphorylation sites, supporting the idea that this protein plays a crucial role in the motility of spermatozoa. The presence of a potential N-myristoylation site suggests that this protein may covalently bind to the inner leaflet of the plasma membrane (PM), which in turn may explain the close association of the FS and PM from early development. Developmental northern blot analysis and in situ hybridization revealed that the FS 75 mRNA is haploid expressed, with an abundant level of mRNA in late round spermatids. Maximum levels of the FS 75 polypeptide, as determined by immunocytochemistry, correlated with a rapid decline in corresponding mRNA levels in step 14-16 spermatids. Since transcription termination occurs several steps earlier, the bulk of FS 75 mRNA appears to be translationally regulated.

Maternal asthma and idiopathic preterm labor.

Previous studies suggest that women with asthma are at increased risk of preterm birth. Moreover, drugs (especially beta-agonists) used to treat asthma are also used to treat preterm labor. The authors carried out a case-control study of 555 women from three hospital centers with idiopathic preterm labor (< 37 weeks), including two overlapping (i.e., non-mutually exclusive) subsamples: cases with early idiopathic preterm labor (< 34 weeks) and cases with idiopathic recurrent preterm labor (< 37 weeks plus a previous history of preterm delivery or second-trimester miscarriage). Controls were matched to cases according to race and smoking history prior to and during pregnancy. All subjects responded in person to questions about atopic, respiratory, obstetric, and sociodemographic histories. Subjects in the early and recurrent preterm labor subsamples were also asked to undergo spirometric testing with methacholine challenge 6-12 weeks after delivery. Cases were significantly more likely to report histories of asthma symptoms and physician-diagnosed asthma (matched odds ratios of 2-3) than controls, particularly those cases with recurrent preterm labor. No significant associations were observed, however, with methacholine responsiveness. These results could not be explained by residual confounding by smoking or other variables, nor by selective recall of asthma symptoms and histories by cases. Women with asthma are at increased risk of idiopathic preterm labor. The fact that no such association was seen with methacholine responsiveness suggests that nonatopic, noncholinergic mechanisms may link bronchial and uterine smooth muscle lability.