Diet and oral premalignancy in female south Indian tobacco and betel chewers: a case-control study

The diets of 158 tobacco/betel quid-chewing women diagnosed with oral premalignant lesions and 155 quid-chewing but lesion-free controls, frequency matched for age, tobacco/betel habits, and socioeconomic status, were assessed using a food frequency survey. Index scores generated from the food frequency survey indicated that the mean levels of consumption for foods of animal origin (p < 0.001), total vegetables and fruit (p = 0.001), vegetables alone (p = 0.006), fruits alone (p = 0.006), and green leafy vegetables (p = 0.015) were significantly lower in cases than in controls. The mean index score for cobalamin (vitamin B12) was lower in cases with a borderline significance (p = 0.05), whereas the indexes for folate and carotene were not significantly different. The analysis of index scores estimating the number of 100-g servings per week of foods of animal origin [meat, eggs, milk, curd (yogurt), fish] consumed revealed that women who ate fewer servings were more likely to have premalignant lesions than those who ate more animal foods [odds ratio (OR) 3.38, 95% confidence interval (CI) 2.07-5.54, p = 0.001]. The risk for low consumption of vegetables was not as significant as that for foods of animal origin. However, those eating low levels of vegetables and low levels of foods of animal origin were at the greatest risk for lesions (OR 5.38, 95% CI 1.72-22.17, p < 0.05). In South Indian female tobacco/betel chewers, a diet deficient in foods of animal origin appears to be a more significant risk factor for oral premalignancy than is a diet deficient in fruits and vegetables.     

Iron uptake by cultured lens epithelial cells

Background: Transferrin and Fe concentrations increase in the intraocular fluids in pathological conditions and the lens accumulates Fe during ocular inflammation. Tissues take up Fe from transferrin by two mechanisms, receptor-medicated endocytosis of diferric transferrin and a process occurring at the cell membrane which may be mediated by an oxido-reductase. However, Fe metabolism, transport and storage have not been previously investigated in the lens. This study was designed to characterize the uptake of Fe from transferrin by lens epithelial cells in culture. Methods: Primary, secondary and tertiary cultures of canine lens epithelial cells and cultures obtained from cataractous lenses were studied. Uptake of ⁵⁹Fe from transferrin by these cultured cells was measured. Transferrin receptor populations were determined in receptor-binding assays. Results: There was a distinct relationship between the amount of Fe-transferrin added and the amount of Fe taken up, which was linear for the primary cultures but significantly reduced for the secondary, tertiary and cataract cultures (252±21, 169±14, 153±14 and 96±2 ng Fe/mg protein, respectively).Transferring receptor expression in lens cell cultures was reduced 10-fold within 2 days of addition of serum to cells grown in low-Fe, serum-free medium for 1 week. Conclusions: The reduction of Fe uptake by the subcultured and cataract cell lines probably reflects a decrease in transferrin receptor expression and in the activity of an alternative pathway for Fe transferrin uptake occurring over time. This reduced Fe uptake may result from long-term exposure to relatively high Fe concentration in the media. A reduction in the expression of the transferrin receptor after incubation with high concentrations of Fe supports this conclusion.     

The impact of multifocused interventions on sharps injury rates at an acute-care hospital.

OBJECTIVE: To determine the impact of a multifocused interventional program on sharps injury rates. DESIGN: Sharps injury data were collected prospectively over a 9-year period (1990-1998). Pre- and postinterventional rates were compared after the implementation of sharps injury prevention interventions, which consisted of administrative, work-practice, and engineering controls (ie, the introduction of an anti-needlestick intravenous catheter and a new sharps disposal system). SETTING: Sharps injury data were collected from healthcare workers employed by a mid-sized, acute-care community hospital. RESULTS: Preinterventional annual sharps injury incidence rates decreased significantly from 82 sharps injuries/1,000 worked full-time-equivalent employees (WFTE) to 24 sharps injuries/1,000 WFTE employees postintervention (P<.0001), representing a 70% decline in incidence rate overall. Over the course of the study, the incidence rate for sharps injuries related to intravenous lines declined by 93%, hollow-bore needlesticks decreased by 75%, and non-hollow-bore injuries decreased by 25%. CONCLUSION: The implementation of a multifocused interventional program led to a significant and sustained decrease in the overall rate of sharps injuries in hospital-based healthcare workers.     

Quantification of Mitral and Tricuspid Regurgitation Using Jet Centerline Velocities: An In Vitro Study of Jets in an Ambient Counterflow

A method for quantifying mitral and tricuspid regurgitant volume that utilizes a measure of jet orifice velocity U(0) - m/sec), a distal centerline velocity (U(m) - m/sec), and the intervening distance (X - cm) was recently developed; where jet flow rate (Q(cal) - L/min) is calculated as Q(cal) = (U(m)X)(2)/(26.46U(o)). This method, however, modeled the regurgitant jet as a free jet, whereas many atrial jets are counterflowing jets because of jet opposing intra-atrial flow fields (counterflows). This study concentrated on the feasibility of using the free jet quantification equation in the atrium where ambient flow fields may alter jet centerline velocities and reduce the accuracy of jet flow rate calculations. A 4-cm wide chamber was used to pump counterflows of 0, 4, and 22 cm/sec against jets of 2.3, 4.8, and 6.4 m/sec originating from a 2-mm diameter orifice. For each counterflow-jet combination, jet centerline velocities were measured using laser Doppler anemometry. For free jets (no counterflow), flow rate was calculated with 98% mean accuracy. For all jets in counterflow, the calculation was less accurate as: (i) the ratio of jet orifice velocity to counterflow velocity decreased (U(o)/U(c), where U(c) is counterflow velocity), i.e., the counterflow was relatively more intense, and (ii) centerline measurements were made further from the orifice. But although counterflow lowered jet centerline velocities beneath free jet values, it did so only significantly in the jet's distal portion (X/D > 16, i.e., >16 orifice diameters from the origin of the jet). Thus, the initial portion (X/D < 16) of a jet in counterflow behaved essentially as a free jet. As a result, even in significant counterflow, jet flow rate was calculated with >93% accuracy and >85% for jets typical of mitral and tricuspid regurgitation, respectively. Counterflow lowers jet centerline velocities beneath equivalent free jet values. This effect, however, is most significant in the distal portion of the jet. Therefore, regurgitant jets, although not classically free because of systolic atrial inflow or jet-induced intra-atrial swirling flows, will decay in their initial portions as free jets and thus are candidates for quantification with the centerline technique. (ECHOCARDIOGRAPHY, Volume 13, July 1996)     

Frontiers of operative laparoscopy: a review and critique of the evidence.

OBJECTIVE: This report reviews the evidence supporting the use of operative laparoscopy for a number of expanded indications in gynecology. STUDY DESIGN: Studies published in English were identified through a Medline search back to 1966 for literature listed under the medical subject heading of "peritoneoscopy"; this search was supplemented by reviews of reference lists and discussions with experts. RESULTS: Fair evidence exists to recommend use of laparoscopy for ectopic pregnancy, ovarian biopsy, and treatment of polycystic ovarian syndrome resistant to clomiphene citrate therapy. Evidence concerning other indications is inadequate to allow recommendations. CONCLUSIONS: Mechanisms are urgently needed to evaluate surgical innovations in gynecology with the same degree of scientific rigor currently afforded medical innovations. Without surgical technology assessment, the current double standards in gynecologic therapy will persist.     

Increased platelet aggregation in patients receiving chlorpromazine: responses to 5-hydroxytryptamine, dopamine and N-dimethyl dopamine

1 Platelet aggregation responses to 5-HT, dopamine, N-dimethyl dopamine and adenosine diphosphate were compared in normal subjects and patients treated with chlorpromazine (CPZ) for longer than 6 months.

2 We confirmed our previous finding that 5-HT induced aggregation is enhanced in CPZ treated patients.

3 Increased aggregation responses were also observed with dopamine and N-dimethyl dopamine.

4 Quantitative comparisons of aggregation rates and total changes in optical density of platelet rich plasma relative to adenosine diphosphate showed significant increases with 5-HT, dopamine and N-dimethyl dopamine.

5 Implication of dopaminergic mechanisms in the central effects of phenothiazines suggests that changes in dopamine induced aggregation responses may be useful in attempting correlations of clinical and pharmacological effects.

     

The organization of effective hospitals

An analysis of 32 hospitals for effectiveness, organization structure, integrative mechanisms, and coordinative aspects reveals some common characteristics that can guide managers in structuring their own organizations.     

Effects of voltage-gated ion channel modulators on rat prostatic cancer cell proliferation: comparison of strongly and weakly metastatic cell lines

BACKGROUND: The strongly metastatic MAT-LyLu and the weakly metastatic AT-2 rat prostatic cancer cell lines have been shown to express voltage-gated ion channels differentially. In the present study, the possible contribution of voltage-gated ion channel activity to the proliferation of these cell lines was investigated, in a comparative approach. METHODS: Several voltage-gated ion channel modulators were tested for their effects on proliferation over 54 hr, using an in vitro assay. The modes of action of the chemicals were monitored by electrophysiological (patch-clamp) recording. RESULTS: The voltage-gated K(+) channel blockers 4-aminopyridine (4-AP; 2 mM), margatoxin (5 nM), charybdotoxin (4.5 nM), and verapamil (50 microM) inhibited the K(+) channels of both cell lines by between 38-65% and reduced the proliferation of the AT-2 cell line, in a dose-dependent manner, by 8-51%. However, only 4-AP reduced proliferation of the MAT-LyLu cell line. Tetrodotoxin (6 microM) blocked completely the voltage-gated Na(+) channel expressed selectively in the MAT-LyLu cell line, but had no effect on the proliferation of either cell line. On the other hand, the presumed Na(+) channel "opener" veratridine (10-50 microM) reduced significantly, in a dose-dependent manner, the proliferation of both cell lines by up to approximately 30%. CONCLUSIONS: We conclude that the mechanism(s) controlling the proliferation of the weakly metastatic AT-2 cells involves voltage-gated K(+) channels. In contrast, the proliferation of strongly metastatic MAT-LyLu cells is much less dependent upon voltage-gated K(+) channel activity.