Correlates of current cigarette smoking among in-school adolescents in the Kurdistan region of Iraq

Background  

Many adult cigarette smokers initiated the habit as adolescents. Adolescent tobacco use may be a marker of other unhealthy behaviours. There are limited data on the prevalence and correlates of cigarette smoking among in-school adolescents in Iraq. We aimed to estimate the prevalence of, and assess the socio-demographic correlates of current cigarette smoking among in-school adolescents in Kurdistan region of Iraq.     

Pharmacokinetics and metabolism of the methotrexate metabolite 2, 4-diamino-N(10)-methylpteroic acid

The novel methotrexate (MTX) rescue agent carboxypeptidase-G(2) (CPDG(2)) converts >98% of plasma MTX to 2, 4-diamino-N(10)-methylpteroic acid (DAMPA) and glutamate in patients with MTX-induced renal failure and delayed MTX excretion. DAMPA is eliminated more rapidly than MTX in these patients, suggesting nonrenal elimination. The pharmacokinetics and metabolism of DAMPA were studied in four nonhuman primates with reverse-phase HPLC with UV, photodiode array detection, and mass spectroscopy. The mean peak plasma DAMPA concentration was 51 microM and the plasma disposition was described by a three-compartment open model with first order elimination. The mean clearance of DAMPA was 1.9 l/kg/h and the mean terminal half-life was 51 min. Forty-six percent of the dose was excreted in the urine as parent compound. Three DAMPA metabolites, hydroxy-DAMPA, DAMPA-glucuronide, and hydroxy-DAMPA-glucuronide, were identified in plasma and urine. These metabolites also were identified in plasma from patients who received CPDG(2) as an MTX rescue agent. The cytotoxicity of DAMPA and its effect on MTX cytotoxicity were assessed in the Molt-4 human leukemic cell line. DAMPA was not cytotoxic and did not significantly alter the cytotoxicity of MTX. In nonhuman primates metabolism of DAMPA is a major route of DAMPA elimination, and metabolism underlies the more rapid elimination of DAMPA versus MTX in patients with MTX-induced renal dysfunction after administration of CPDG(2).     

Circulating insulin inhibits glucagon secretion induced by arginine in type 1 diabetes

OBJECTIVE: To evaluate if insulin has a suppressive effect on the glucagon secretion stimulated by arginine in type 1 diabetes. RESEARCH DESIGN AND METHODS: The alpha-cell response to an i.v. bolus of arginine (150mgkg(-1)) followed by an infusion of arginine (10mgkg(-1)min(-1)) was studied in random order during either low dose infusion (LDT) or high dose infusion (HDT) of insulin in ten patients with type 1 diabetes. The blood glucose level was clamped at an arterialized level of 5mmoll(-1) by a variable infusion of glucose. Venous C-peptide, glucagon, growth hormone, and insulin were analyzed. RESULTS: The mean plasma concentration of insulin was four times higher during the HDT. The C-peptide level did not differ between the LDT and the HDT. During the LDT in response to arginine the blood glucose level increased from 5.0 to 5.8mmol l(-1) although the glucose infusion was markedly reduced, while no change was seen during the HDT. A significantly smaller increase in the glucagon levels during the HDT was seen (area under the curve of 413+/-45 vs 466+/-44pgml(-1)h(-1), P=0.03) while the growth hormone levels were almost identical. CONCLUSION: This study demonstrates that a high level of circulating insulin exerts an inhibitory effect on the glucagon response to arginine in type 1 diabetes. Thus, the suppressive effect of insulin on the glucagon release from the alpha-cell seems to be general and not only dependent on stimulation by hypoglycemia.     

Differences in postperinatal infant deaths between north and southern Derbyshire.

In depth confidential inquiries on all post-perinatal infant deaths were carried out for two years in North and Southern Derbyshire District Health Authorities in order to explore why the postperinatal death rates and cot death rates have been consistently higher in Southern than in North Derbyshire. It was found that the death rates for probably inevitable deaths and for 'idiopathic' cot deaths were the same in both districts. The differences in the death rates lay in the group of partly explained cot deaths. Adverse social factors associated with each death were recorded and an estimate made of their relevance to the individual deaths. The group of deaths most amenable to intervention was those of category B (partly explained cot deaths). As judged by the Jarman index there are more areas of deprivation in Southern than in North Derbyshire.     

The influence of spontaneous accelerations of fetal heart rate on umbilical artery velocity waveforms

For clinical interpretation of Doppler waveforms, it is important to establish the extent to which fetal heart rate changes affect the umbilical artery velocity waveform. Umbilical artery waveforms were measured with continuous wave ultrasonography during spontaneous accelerations of the fetal heart rate in 20 uncomplicated, near-term pregnancies. On average, an acceleration of 20 beats/min of fetal heart rate within an individual was associated with a reduction in the systolic/diastolic velocity ratio of 0.25. There was, however, considerable variability in the response, and in six patients the systolic/diastolic ratio actually increased with heart rate. We conclude that fetal heart accelerations within the normal range cause only small and variable changes in the systolic/diastolic ratio.     

Postnatal development of enzyme activities associated with protection against oxidative stress in the mouse

A number of enzyme systems are important in the protection of cells from chemical-induced oxidative damage. Little is known of the relative importance of these enzymes during postnatal development and its is possible that changes in their activity during this period may alter the susceptibility to toxic agents. This study investigated the activities of glutathione peroxidase, glutathione reductase, catalase, superoxide dismutase, gamma-glutamyl-cysteine synthetase and glutathione synthetase in the liver, lung and kidney of postnatal and adult mice. The first 3 postnatal weeks are characterized by marked changes in the activities of enzymes that protect against oxidative stress (glutathione peroxidase/reductase, catalase and superoxide dismutase). Overall, the activity of these enzymes suggests that the mouse has a higher level of protection against peroxides at various stages during this period but lower capacity to detoxify superoxide anions. The activities of the glutathione-synthetic enzymes (gamma-glutamylcysteine synthetase and glutathione synthetase) were significantly lower in the kidney of the postnatal mice, but the liver and lung had levels similar to those in the adult. Glutathione turnover in the liver of 2-week-old mice was not different from that in adults. The results indicate a complex pattern of development in the activities of detoxification enzyme systems during postnatal development.     

The effect of cosmetic rhinoplasty on nasal patency

Fifty patients who primarily desired cosmetic improvement underwent nasal airflow studies using posterior rhinomanometry before and after reduction rhinoplasty. There was no significant difference in nasal resistance before and after surgery. This study demonstrates that neither subjective nor objective nasal obstruction follows reduction rhinoplasty, despite the potential for a decreased cross-sectional area of the valve region.     

Cardiac electromechanical dissociation in the hypoxic fetal sheep may have clinical implications.

OBJECTIVES: Our purpose was to determine the sequence of fetal cardiac electrical and mechanical events associated with acute hypoxic acidemia and to correlate those events with terminal fetal heart rate patterns preceding fetal death. STUDY DESIGN: Eight acutely catheterized fetal sheep were rendered hypoxic by placental embolization with microspheres until fetal death occurred. The fetal electrocardiogram, Doppler cardiogram, left ventricular and aortic pressures, and fetal heart rate were continuously recorded. RESULTS: All eight fetuses showed a terminal bradycardia consisting of two phases: an initial phase of falling ventricular pressures, culminating in mechanical asystole, and a subsequent phase after asystole during which the electrocardiographic signal persisted for an average duration of 15.2 +/- 8.7 minutes (range 3.1 to 32.4) and triggered a Hewlett-Packard 8040A monitor to show a heart rate pattern. CONCLUSIONS: The phenomenon of cardiac electromechanical dissociation may be occurring during similar terminal bradycardias that are observed in human labor and explains the delivery of a fresh stillbirth in spite of the recording of an electrocardiographic signal from a scalp electrode.     

Breast MRI: Early experience with a 3-D fat-suppressed Gradient Echo Sequence in the evaluation of breast lesions

The early clinical experience with a 3-Dimensional Fourier Transform Gradient Echo sequence with fat suppression in the evaluation of breast masses is reported. Ten female patients with breast malignancies were pre-operatively evaluated with this sequence and the results compared with the pathological specimens. The scanning protocol included a noncontrast sequence followed by an immediate post-contrast sequence (completed 4.5 min after intravenous contrast injection) and a delayed sequence. Images were assessed for maximum lesion and parenchymal enhancement, lesion size and additional enhancing abnormalities. In six patients, malignant masses enhanced maximally on the immediate post-contrast sequence with parenchyma enhancing maximally on delayed images. In three cases, there was preferential enhancement of malignant lesions over normal parenchyma but to a similar degree on both post-contrast sequences. In one case, both the lesion and parenchyma enhanced maximally on the delayed sequence. Magnetic resonance assessed lesion size accurately and also detected satellite malignancies in one case. However, lesion grade, associated in situ carcinoma and lymphovascular invasion did not impact on lesion enhancement. In this small series, a contrast-enhanced, fat-suppressed 3-D Gradient Echo Sequence detected breast carcinoma with high sensitivity. The technique holds promise but further evaluation is required.