Metal-induced infidelity of DNA synthesis

Summary A number of metals have been demonstrated to be mutagens in procaryotic and eucaryotic organisms as well as carcinogens in experimental animals. Epidemiologic studies have indicated that Ni, Cr, and As are involved in human carcinogenesis. We have hypothesized that the active molecular species is the cation and that metal induced mutations result from incorrect base-substitutions during DNA replication. This is supported by the observations that metal ions diminish the fidelity of DNA synthesis in vitro using a variety of DNA polymerases. There is a significant correlation between the metals that decrease fidelity and those that have been reported to be mutagenic and carcinogenic. Thus, metal carcinogens are no exception to the general postulate that carcinogens can be identified by their effects on DNA.     

Surgical elimination of the retracted submental fold during double chin correction

In some cases of double chin, the submental fold can become quite obvious. It can persist or even be deepended following a submental fatpad resection if the incision is made following the fold. The steps involved in eliminating this fold are: (1). A curved incision is made 1 cm in front of the fold. (2). The excess fat is reduced, leaving a 1 cm layer attached to the skin. (3). The fold is filled by sliding forward a fat flap taken from the fat remaining on the skin. (4). The sutures in the fat and the skin are not superimposed, to avoid recurrance of the fold.     

Extended field radiation therapy in Hodgkin's disease: analysis of failures

A retrospective analysis of 116 primary cases of stage I, II and III-A Hodgkin's disease demonstrated 27 failures, fourteen confirmed by biopsy. Twenty of the 27 (74%) were in lymph node areas only and seven had extranodal extensions. The most frequent site of failure was the hilar nodes and contiguous lung. The majority of failures (78%) occurred within 30 months of treatment and the cause of failure determined in 23 (85%), sixteen of which were due to technical errors of irradiation. Analysis of the dosimetry in the mediastinal, hilar nodes and contiguous lung failures revealed three factors which may have contributed to a low dose. These factors are: 1) the equivalent square, 2) off-axis beam diminution, and 3) the anteroposterior dose profile. Combined radiation therapy and chemotherapy was more effective than either modality alone in the treatment of these failures.     

Risk factors for enteric perforation in patients with typhoid Fever

A case-control study was performed using the records of patients hospitalized for typhoid fever at Dicle University Hospital, Diyarbakir, Turkey, between 1994 and 1998. Case patients with enteric perforation were compared with control patients with typhoid fever but no enteric perforation. Risk factors for perforation were determined using logistic regression modeling. Forty case patients who had surgery because of typhoid enteric perforation were compared with 80 control patients. In univariate analyses, male sex (p = 0.01), age (p = 0.01), leukopenia (p = 0.01), inadequate antimicrobial therapy prior to admission (p = 0.01), and short duration of symptoms (p = 0.01) were significantly associated with perforation. In multivariate analysis, male sex (odds ratio (OR) = 4.39, 95% confidence interval (CI): 1.37, 14.09; p = 0.01), leukopenia (OR = 3.88, 95% CI: 1.46, 10.33; p = 0.04), inadequate treatment prior to admission (OR = 4.58, 95% CI: 1.14, 18.35; p = 0.03), and short duration of symptoms (OR = 1.22, 95% CI: 1.10, 1.35; p = 0.001) were significant predictors of perforation. A short duration of symptoms, inadequate antimicrobial therapy, male sex, and leukopenia are independent risk factors for enteric perforation in patients with typhoid fever.