Arsenic trioxide–loaded, microemulsion-enhanced cytotoxicity on MDAH 2774 ovarian carcinoma cell line

The antiproliferative effect of As(2)O(3)-loaded microemulsion (As(2)O(3)-M) on human MDAH 2774 ovarian cancer cells was compared with a regular solution of the As(2)O(3). We used MDAH 2774 as model cell lines for ovarian cancer. The (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide) (XTT) and trypane blue dye exclusion tests were used to evaluate cytotoxicity. Apoptotic effect of solutions was evaluated using cell death detection kit. Standard microemulsion formulation used in this experiment contains 5 x 10(-6) M As(2)O(3). It was clearly demonstrated that As(2)O(3)-M had a significant cytotoxic effect on MDAH 2774 cell line, and the cytotoxic effect of As(2)O(3)-M was significantly higher than that of regular As(2)O(3) solutions. Even approximately 6000 times diluted microemulsion formulation loaded with 5 x 10(-6) M As(2)O(3) showed a cytotoxic effect. As a result, this diluted concentration (approximately 8 x 10(-10) M) was found to be approximately 6000 times more effective than regular As(2)O(3) solutions (5 x 10(-6) M). Moreover, this diluted concentration resulted in 1.5-fold enhancement of apoptosis. According to the in vitro cytotoxicity studies, we concluded that by incorporating As(2)O(3) into the microemulsion (As(2)O(3)-M), which is a new drug carrier system, it is possible to increase antiproliferative effect of regular As(2)O(3) on MDAH 2774 cells. Translating these results to in vivo conditions would open new windows in the treatment of ovarian cancer.     

Developmental aspects of language articulation in preterm and small fullterm infants]

The data to be discussed in this paper are drawn from a study of three groups of infants: small (low birth weight less than 10 centile for gestational age), preterm (gestational age less than 37 weeks) and full term. The total population of this study consisted of 12 children (4 subjects for each group). The purpose of the study was to examine phonetic and lexical development in these three populations to determine both normal and delayed patterns of this development over the second year of life. The time sampled for early behaviors were 18, 19, 20, and 21 months, based on chronological age. The spontaneous verbal productions of the subjects were tape-recorded and transcribed using phonetic symbols (IPA). Comparison were made between preterm and full term infants based on both chronological and gestational age. The data resulting from the comparison of our subjects on these parameters provide us with evidence that there can be early indicators of later speech and lexical development of the group of preterm infants.     

Nitroreduction is not involved in the genotoxicity of 2-nitropropane in cultured mammalian cells

We have investigated the importance of nitroreduction for the genotoxicity of the carcinogen 2-nitropropane (2-NP) in primary cultures of rat hepatocytes and in V79 Chinese hamster cells. Induction of DNA repair synthesis was used as an indicator of genotoxic effects in hepatocytes. Genotoxicity in V79 cells was determined as induction of DNA repair, micronuclei and mutations to 6-thioguanine (TG) resistance. Both hepatocytes and V79 cells were found capable of reducing and oxidizing 2-NP. Reduction of 2-NP was indicated by the formation of acetone oxime, the tautomeric form of 2-nitrosopropane, the first reduction product of 2-NP. Oxidation of 2-NP was indicated by the production of acetone and nitrite. 2-NP strongly elicited repair in hepatocytes, but acetone oxime and the products of a possible further nitroreduction, isopropyl hydroxylamine (IPHA) and 2-aminopropane did not. None of the reduction products caused repair synthesis in V79 cells. However, in these cells IPHA and 2-NP increased the frequency of TG-resistant mutants. IPHA also markedly induced micronuclei. This was not seen with 2-NP. Acetone oxime was not genotoxic in V79 cells. The observations suggest that reduced metabolites are responsible neither for the induction of DNA repair synthesis by 2-NP in hepatocytes nor for the induction of gene mutations by 2-NP in V79 cells.     

Recruiting future neuroscientists: what asking the recruits can teach us.

Many different strategies are used to recruit students into scientific research careers, including neuroscience research. These strategies are rarely based on knowledge about students; instead, activities are selected based on their ease of implementation. The goal of the LEARN Project is to encourage high school students into mental health science research using the theme of learning and memory. One intervention the authors developed is five Web-based biographies introducing students to contemporary neuroscientist role models studying learning and memory. To guide the design of this intervention, the authors created a survey to determine where students obtain career information and who and what influences their career selection. In a convenience sample of 124 students, the authors found that almost all students use the Internet for information about careers, in addition to consulting family members and teachers. Students' career selections are influenced most by family members, teachers, and people already in the field. The most important factors students look for in their future career are money, fun, and a good match between current interests and future careers. The data affirm the value of outreach efforts that go beyond students to include a broader audience of parents and teachers who play a critical role in career selection.     

Fenestration and occlusion of the posterior semicircular canal for benign positional vertigo

Benign positional vertigo is a potentially disabling condition characterized by episodic vertigo following certain provocative head movements. In most patients it is self limiting; however, in a few it may prove intractable, causing considerable social morbidity. In these patients surgery may be considered. Surgery previously involved section of the vestibular or singular nerves, involving a significant risk to hearing and to the facial nerve. Ablation of the labyrinth may even be considered. The new surgical technique of occlusion of the posterior semicircular canal has proved to be curative in most patients with benign positional vertigo with little risk to hearing. This paper describes our experience of fenestration and occlusion of the posterior semicircular canal in four patients.     

Renal involvement in the Laurence-Moon-Bardet-Biedl syndrome: report of five cases

.We report five patients with Laurence-Moon-Bardet-Biedl syndrome (LMBBS) who had renal involvement. Intravenous pyelography showed bilateral or unilateral calyceal clubbing and blunting in all patients. In addition, one patient had a parapelvic cyst in the left kidney and another had bilateral lobulated renal outlines of the fetal type. One patient had a urinary concentrating defect and two patients showed increased fractional sodium excretion. Estimated tubular phosphate reabsorption values were in normal limits in all of five patients. No patient had a urine acidification defect, proteinuria, glycosuria, or hyperaminoaciduria. One patient died from end-stage renal failure. The remaining four patients had normal serum creatinine values and estimated creatinine clearances. ^99mTechnetium-diethylenetriamine pentaacetate renal scanning showed prolonged and delayed concentration and delayed excretion in three of the four patients who survived. A focal scar was determined on the left kidney of one of four patients by ^99mtechnetium-dimercaptosuccinic acid renal scanning. All LMBBS cases with or without renal symptoms should be routinely evaluated for renal abnormalities. Renal scanning is a valuable method, especially for determining the renal involvement in the early stage of disease. Received November 14, 1995; received in revised form and accepted May 23, 1996