Non-adherence to antihypertensive medication is very common among resistant hypertensives: results of a directly observed therapy clinic.

Resistant hypertension is common among the hypertensive population with reported prevalence of 12 to 15%. These patients have a higher cardiovascular risk and consequently a poorer cardiovascular prognosis. Suboptimal adherence with antihypertensive medication is a common contributing factor in apparent treatment-resistant hypertension. Patients were observed taking their medications under direct supervision at our directly observed therapy (DOT) clinic. At the DOT clinic visit, patients were fitted with a 24-h ambulatory blood pressure (ABP) monitor and each drug, at currently prescribed dose, was administered by a nurse; at an hourly interval and patient observed for 7 h. ABP readings between pre and post DOT clinic were compared. Fifty out of 56 patients had complete data on the ABP. Twenty four were female and the mean (s.d.) age was 62.0 (11.0) years. On the basis of the study methods that differentiated patients according to their BP response during the DOT clinic, twenty-five (50.0%) patients were deemed to be truly resistant (24-h ambulatory systolic blood pressure (SBP) fall <5 mm Hg) and the remaining 25 were deemed to have clinically significant non-adherence (24-h ambulatory SBP fall ⩾5 mm Hg) to prescribed therapy. In non-adherent patients, the mean 24-h ambulatory BP drop observed was 19.5/9.4 mm Hg (P<0.001 for both). Our results suggest that non-adherence is very common among patients considered to have apparent treatment-resistant hypertension. DOT clinic can be an effective method of identifying the truly resistant hypertensive patients.

Identification and characterization of a novel Iraqi isolate of Fusarium pseudograminearum causing crown rot in wheat.

Crown rot is one of the main important fungal diseases affecting wheat in many areas of the world, including Australia, USA, and Iran. Until now, there had been no report of this pathogen in Iraq. Plants displaying crown rot symptoms were observed in Shaat Alarab (Basra, Iraq); we investigated the causal agent of the disease. Samples were surface-sterilized in bleach (1% available chlorine) and cultured on quarter-strength potato dextrose agar plates. DNA was extracted from fungal mycelia, using a modified CTAB protocol. The ITS/5.8S regions were amplified using primer pair ITS1 and ITS4. PCR products purified using a gel extraction kit were sequenced. The sequence that was detected was used to BLAST against NCBI data. The most similar sequence was the ITS/5.8S rDNA region of Fusarium pseudograminearum (strain NRRL28062), showing 97.95% identity. This species normally causes crown rot, resulting in severe damage under dry spring conditions. A pathogenicity test employed to assess the disease-causing ability of the strain showed significant disease symptoms up to 57% infected spikelets. The results confirmed the presence of F. pseudograminearum as a causal agent of wheat crown rot in Iraq. The presence of this pathogen demands further investigations to develop resistant cultivars and/or mechanical control.

The effects of acetazolamide on the ventilatory response to high altitude hypoxia.

Acetazolamide treatment ameliorates the symptoms of AMS; however, the mechanism by which this occurs is unclear. To examine the effects of acetazolamide on oxygenation, CO2 responsiveness and ventilatory pattern during acute exposure to HA, we studied two groups of subjects at SL and following rapid (less than 8 h) transport to HA. Acetazolamide or placebo tablets were given to groups 1 and 2, respectively, in a double-blind manner after baseline SL measurements; treatment was continued during HA exposure. There was no difference in the ventilatory pattern at HA, between the two groups. While the Ve achieved in response to CO2 at HA vs SL was much greater in each group the percent change from baseline at HA versus that at SL was not significantly different. The beneficial effects of acetazolamide in AMS are associated with a higher level of ventilation at HA and better oxygenation: CO2 chemosensitivity is not affected by acetazolamide at HA.

Cardiocirculatory responses to upright tilt at sea level and high altitude.

A collaborative study was conducted to measure the cardiocirculatory responses to upright tilt in eight young men at sea level (SL); after 1h at 4300m simulated altitude (SA) and at 18h, 66h and 114h during residence at 4300m (HA). Heart rate (HR), stroke volume (SV), cardiac output (CO), calf blood flow (CBF), blood pressure (BP) and total peripheral resistance (TPR) were obtained during supine rest and after 13 min of 60 degrees head-up tilt using an impedance monitor and an electrosphygmomanometer. SL to HA changes in blood volume (BV) were calculated from hematocrit and hemoglobin values. Supine HR, TPR and BP were increased while SV, CO and CBP were reduced SL to HA (P less than .05). HR and BP in the upright position were increased SL to HA (P less than .05). The responses to tilt (delta supine to upright) were unaltered SL vs SA. With prolonged exposure, SV, CO, TPR and CBP responses to tilt were reduced (P less than .05). The reduced responses to tilt at HA were associated with a 10% decline in BV (P less than .01). It was concluded that the reduction in SV during tilt at SL and SA was compensated for by increases in HR and TPR in order to maintain BP. After 18h HA, BP in the upright position was maintained only by an increase in HR.