Alternative water management scenarios for Saudi Arabia

Natural Resources;environmental economics

An early-onset recessive cerebellar disorder with distal amyotrophy and, in two patients, gross myoclonia: A probable ataxia telangiectasia variant

We report a family of 4 siblings from a non-consanguineous marriage, presenting with an early onset recessive cerebellar ataxia and progressive distal limb wasting. Ocular or other telangiectasias were absent. There were neither frequent infections nor immunodeficiencies. The two youngest patients exhibited an incapacitating myoclonus which abated markedly after 20 years. Late onset diabetes was demonstrated in 3 patients. Hypogonadism was not a feature and there was a prolonged survival in the 4 patients. The oldest sibling died of a pancreatic adenocarcinoma. α-Fetroprotein was elevated with normal carcinoembryonic antigen values in three patients. Cytogenetic analysis and radioresistant DNA synthesis was compatible with the diagnosis of ataxia-telangiectasia. This family probably represents a rare variant of ataxia-telangiectasia

Symptoms and functional status of patients with disseminated cancer visiting outpatient departments

Considerable research has focused on pain and other symptoms in terminal cancer patients referred to hospices and palliative care services. These patients differ from Dutch cancer patients in the palliative stage of their disease because the latter are cared for by general practitioners at home and medical specialists in outpatient departments. To clarify the experience of these Dutch patients, a study was started to investigate the prevalence and severity of pain and other symptoms as well as the functional status of consecutive patients visiting oncology outpatient departments for follow-up. After randomization, one group (I) of patients was interviewed at home by a general practitioner using structured questionnaires. The other group (II) received the questionnaires by mail, and scored the symptoms independently. The results of the symptom assessment show that patients in groups I and II suffered 2.4 (SD = 1.7) and 2.8 (SD = 2.0) symptoms, respectively. Between 30% and 40% of all patients reported constipation, nausea, loss of appetite, coughing, and dyspnea. These percentages were 50% lower when only moderate, severe, or extremely distressing symptoms were included. Sixty percent of all patients had pain, and 20% indicated a daytime pain score of 5 or greater on a scale of 0 to 10. Functional status was measured by the COOPWONCA charts; the mean score for the charts "physical fitness" and "daily activities" was 1.5 points lower for cancer patients than a random sample from the community of the same age and gender. The findings of this study should motivate doctors to put more energy in symptom assessment and interventions in palliative care. Record 29 of 32 - SilverPlatter MEDLINE(R)

Integrated sampling-and-sensing using microdialysis and biosensing by particle motion for continuous cortisol monitoring

Microdialysis catheters are small probes that allow sampling from biological systems and human subjects with minimal perturbation. Traditionally, microdialysis samples are collected in vials, transported to a laboratory, and analysed with typical turnaround times of hours to days. To realize a continuous sampling-and-sensing methodology with minimal time delay, we studied the integration of microdialysis sampling with a sensor for continuous biomolecular monitoring based on Biosensing by Particle Motion (BPM). A microfluidic flow cell was designed with a volume of 12 μl in order to be compatible with flowrates of microdialysis sampling. The analyte recovery and the time characteristics of the sampling-and-sensing system were studied using a food colorant in buffer and using cortisol in buffer and in blood plasma. Concentration step functions were applied, and the system response was measured using optical absorption and a continuous BPM cortisol sensor. The cortisol recovery was around 80% for a 30 mm microdialysis membrane with a 20 kDa molecular weight cut-off and a flowrate of 2 μl min−1. The concentration-time data could be fitted with a transport delay time and single-exponential relaxation curves. The total delay time of the sampling-and-sensing methodology was about 15 minutes. Continuous sampling-and-sensing was demonstrated over a period of 5 hours. These results represent an important step toward integrated sampling-and-sensing for the continuous monitoring of a wide variety of low-concentration biomolecular substances for applications in biological and biomedical research.</p

Integrated sampling-and-sensing using microdialysis and biosensing by particle motion for continuous cortisol monitoring

Microdialysis catheters are small probes that allow sampling from biological systems and human subjects with minimal perturbation. Traditionally, microdialysis samples are collected in vials, transported to a laboratory, and analysed with typical turnaround times of hours to days. To realize a continuous sampling-and-sensing methodology with minimal time delay, we studied the integration of microdialysis sampling with a sensor for continuous biomolecular monitoring based on Biosensing by Particle Motion (BPM). A microfluidic flow cell was designed with a volume of 12 μl in order to be compatible with flowrates of microdialysis sampling. The analyte recovery and the time characteristics of the sampling-and-sensing system were studied using a food colorant in buffer and using cortisol in buffer and in blood plasma. Concentration step functions were applied, and the system response was measured using optical absorption and a continuous BPM cortisol sensor. The cortisol recovery was around 80% for a 30 mm microdialysis membrane with a 20 kDa molecular weight cut-off and a flowrate of 2 μl min−1. The concentration-time data could be fitted with a transport delay time and single-exponential relaxation curves. The total delay time of the sampling-and-sensing methodology was about 15 minutes. Continuous sampling-and-sensing was demonstrated over a period of 5 hours. These results represent an important step toward integrated sampling-and-sensing for the continuous monitoring of a wide variety of low-concentration biomolecular substances for applications in biological and biomedical research.</p

Towards continuous monitoring of TNF-α at picomolar concentrations using biosensing by particle motion

The ability to continuously monitor cytokines is desirable for fundamental research studies and healthcare applications. Cytokine release is characterized by picomolar circulating concentrations, short half-lives, and rapid peak times. Here, we describe the characteristics and feasibility of a particle-based biosensing technique for continuous monitoring of TNF-α at picomolar concentrations. The technique is based on the optical tracking of particle motion and uses an antibody sandwich configuration. Experimental results show how the analyte concentration influences the particle diffusivity and characteristic response time of the sensor, and how the sensitivity range depends on the antibody functionalization density. Furthermore, the data clarifies how antibodies supplemented in solution can shorten the characteristic response time. Finally, we demonstrate association rate-based sensing as a first step towards continuous monitoring of picomolar TNF-α concentrations, over a period of 2 h with delay times under 15 min. The insights from this research will enable the development of continuous monitoring sensors using high-affinity binders, providing the sensitivity and speed needed in applications like cytokine monitoring.</p