Oligonucleotide-directed mutagenesis as a general and powerful method for studies of protein function.

We have used oligonucleotide-directed mutagenesis to make a specific change in the beta-lactamase (EC 3.5.2.6) (ampicillin resistance) gene of the plasmid pBR322. Evidence suggests that the active site for this enzyme may include a serine-threonine dyad (residues 70 and 71). By priming in vitro DNA synthesis with a chemically synthesized 16-base oligodeoxyribonucleotide, we have inverted the Ser-Thr dyad to Thr-Ser and thereby generated a mutant with an ampicillin-sensitive phenotype. This "double-mismatch" method is relatively simple and also very general because detection of mutants is at the level of DNA and involves only colony hybridization. Accordingly, the procedure can be applied to any DNA sequence and does not depend on the phenotype of the mutant.     

Klippel-Trénaunay syndrome. An unusual presentation of unilateral leg edema

Klippel-Trénaunay syndrome is a rare congenital condition that classically presents as a triad of varicosities, bone or soft-tissue hypertrophy, and cutaneous hemangiomas. The authors describe a case of this disease in an otherwise healthy patient with unilateral leg edema and intermittent bleeding from prominent ankle varicosities. The diagnosis was made on the basis of clinical presentation, diagnostic studies, and a comprehensive literature review. An overview of the pathology, treatment, and prognosis of this disease is provided.     

Protein feeding pattern does not affect protein retention in young women

This study was undertaken to determine whether a pulse protein feeding pattern was more efficient than a spread pattern to improve protein anabolism in young women as was already shown in elderly women. After a 15-d adaptive period [1.2 g protein/(kg fat-free mass. d)], 16 young women (age 26 +/- 1 y) were given a 14-d diet providing 1.7 g protein/(kg fat-free mass. d), using either a pulse pattern (protein consumed mainly in one meal, n = 8), or a spread pattern (spreading daily protein intake over four meals, n = 8). Nitrogen balance was determined at the end of both the 15-d adaptive and the 14-d experimental periods. Whole-body protein turnover was determined at the end of the 14-d experimental period using [(15)N]glycine as an oral tracer. Nitrogen balance was 17 +/- 5 mg N/(kg fat-free mass. d) during the adaptive period. It was higher during the experimental period, but not significantly different in the women fed the spread or the pulse patterns [59 +/- 12 and 36 +/- 8 mg N/(kg fat-free mass. d) respectively]. No significant effects of the protein feeding pattern were detected on either whole-body protein turnover [5.5 +/- 0.2 vs. 6.1 +/- 0.3 g protein/(kg fat-free mass. d) for spread and pulse pattern, respectively] or whole-body protein synthesis and protein breakdown. Thus, in young women, these protein feeding patterns did not have significantly different effects on protein retention.     

Costal chondroma and chondrosarcoma

The aim of this study was to report two cases of chondrosarcoma located on the chest wall, in order to emphasize the difficulty encountered by the pathologist to differentiate a chondrosarcoma from a chondroma and the importance, in our opinion, of performing a large resection with wide margins in all cases.     

Primary tracheal schwannoma

We report a case of a primary tracheal schwannoma causing symptoms of airway obstruction in a 33-year-old man. Bronchoscopy and computerized tomography demonstrated a polypoid intratracheal mass obstructing 90% of the lumen. Tracheal resection with primary anastomosis was performed. Histologic analysis revealed a benign neurogenic tumor of Schwann cell origin.     

Primary right atrial synovial sarcoma manifesting as transient ischemic attacks

Primary tumors of the heart are rare and most of them benign. The majority of benign cardiac tumors are myxomas while almost all malignant cardiac tumors are sarcomas. We present a case of primary right atrial synovial sarcoma, a form of sarcoma particularly rare in the heart. The tumor manifested clinically as transient ischemic attacks probably related to a patent foramen ovale allowing paradoxical tumor embolization.     

Randomized study on the efficacy of cognitive-behavioral therapy for insomnia secondary to breast cancer, part I: Sleep and psychological effects.

PURPOSE: Chronic insomnia is highly prevalent in cancer patients. Cognitive-behavioral therapy (CBT) is considered the treatment of choice for chronic primary insomnia. However, no randomized controlled study has been conducted on its efficacy for insomnia secondary to cancer. Using a randomized controlled design, this study conducted among breast cancer survivors evaluated the effect of CBT on sleep, assessed both subjectively and objectively, and on hypnotic medication use, psychological distress, and quality of life. PATIENTS AND METHODS: Fifty-seven women with insomnia caused or aggravated by breast cancer were randomly assigned to CBT (n = 27) or a waiting-list control condition (n = 30). The treatment consisted of eight weekly sessions administered in a group and combined the use of stimulus control, sleep restriction, cognitive therapy, sleep hygiene, and fatigue management. Follow-up evaluations were carried out 3, 6, and 12 months after the treatment. RESULTS: Participants who received the insomnia treatment had significantly better subjective sleep indices (daily sleep diary, Insomnia Severity Index), a lower frequency of medicated nights, lower levels of depression and anxiety, and greater global quality of life at post-treatment compared with participants of the control group after their waiting period. Results were more equivocal on polysomnographic indices. Therapeutic effects were well maintained up to 12 months after the intervention and generally were clinically significant. CONCLUSION: This study supports the efficacy of CBT for insomnia secondary to breast cancer.     

Randomized study on the efficacy of cognitive-behavioral therapy for insomnia secondary to breast cancer, part II: Immunologic effects.

PURPOSE: Cross-sectional studies suggest that clinical insomnia is associated with immune downregulation. However, there is a definite need for experimental studies on this question. The goal of this randomized controlled study was to assess the effect of an 8-week cognitive-behavioral therapy (CBT) for chronic insomnia on immune functioning of breast cancer survivors. Previous analyses of this study showed that CBT was associated with improved sleep and quality of life, and reduced psychological distress. PATIENTS AND METHODS: Fifty-seven women with chronic insomnia secondary to breast cancer were randomly assigned to CBT (n = 27) or to a waiting-list control condition (WLC; n = 30). Peripheral-blood samples were taken at baseline and post-treatment (and postwaiting for WLC patients), as well as at 3-, 6-, and 12-month follow-up for immune measures, including enumeration of blood cell counts (ie, WBCs, monocytes, lymphocytes, CD3+, CD4+, CD8+, and CD16+/CD56+) and cytokine production (ie, interleukin-1-beta [IL-1beta] and interferon gamma [IFN-gamma]). RESULTS: Patients treated with CBT had higher secretion of IFN-gamma and lower increase of lymphocytes at post-treatment compared with control patients. Pooled data from both treated groups indicated significantly increased levels of IFN-gamma and IL-1beta from pre- to post-treatment. In addition, significant changes in WBCs, lymphocytes, and IFN-gamma were found at follow-up compared with post-treatment. CONCLUSION: This study provides some support to the hypothesis of a causal relationship between clinical insomnia and immune functioning. Future studies are needed to investigate the clinical impact of such immune alterations.