Proximity Extension Assay in Combination with Next-Generation Sequencing for High-throughput Proteome-wide Analysis

Understanding the dynamics of the human proteome is crucial for developing biomarkers to be used as measurable indicators for disease severity and progression, patient stratification, and drug development. The Proximity Extension Assay (PEA) is a technology that translates protein information into actionable knowledge by linking protein-specific antibodies to DNA-encoded tags. In this report we demonstrate how we have combined the unique PEA technology with an innovative and automated sample preparation and high-throughput sequencing readout enabling parallel measurement of nearly 1500 proteins in 96 samples generating close to 150,000 data points per run. This advancement will have a major impact on the discovery of new biomarkers for disease prediction and prognosis and contribute to the development of the rapidly evolving fields of wellness monitoring and precision medicine.

Effectiveness of antihypertensive treatment in chronic renal failure: to what extent and with which drugs do patients treated by nephrologists achieve the recommended blood pressure?

Adequate control of blood pressure (BP) is important to slow the progression of chronic renal failure (CRF). The Joint National Committee (JNC) VI recommends BP <130/85 mmHg, or <125/75 mmHg if urinary protein excretion exceeds 1 g/d. Angiotensin converting enzyme inhibitors (ACE-I) are considered as first-line agents. The current study is a survey of the degree of goal achievement and prescription patterns of antihypertensive (AHT) medication according to the JNC guidelines in clinical nephrology practice. All patients with CRF, not on renal replacement therapy, treated by nephrologists at the University Hospital of North-Norway were included in this retrospective cross-sectional study. Data on protein:creatinine ratio (PC ratio), BP and AHT drugs prescribed were extracted from the hospital's databases and medical records. A total of 144 patients were included. The patients' age was 62+/-16 years and the serum creatinine value was 210+/-92 micromol/l (mean+/-s.d.). In all, 74 patients (51%) had PC ratio < or =1, 36 (25%) >1, and for 34 (24%) PC ratio had not been measured; 23 (31%) of the patients with PC ratio < or =1 had BP < or =130/85 (139+/-21/78+/-12), and 5 (14%) of those with PC ratio >1 had BP < or =125/75 (145+/-22/85+/-14). Failure to achieve the goal was most commonly due to elevated SBP. In all, 55 % of the patients were prescribed ACE-I or angiotensin receptor blocker (ARB). In conclusion, the recommended BP goals may be difficult to achieve for a high proportion of patients in clinical practice due to difficulty in lowering SBP. There is a potential for improved treatment of hypertension in CRF patients, including increased prescription of ACE-I and ARB.

Cross-contamination in Porcelain Mortars

Porcelain mortars and pestles are frequently used to comminute drug substances on a small scale and (in some cases) in the production of liquid and semisolid suspensions. Although it is generally accepted that removal of a drug substance from a rough surface by rinsing may be difficult and may lead to cross-contamination, no hard data support that theory. In this study, the amount of salicylic acid remaining on a porcelain mortar after different washing procedures was quantified and compared with the amount remaining on a plastic mortar. Drug residues in the "mg" range on the porcelain mortars made common rinsing procedures appear inappropriate, but no traces of drug were detected on plastic mortars. In addition, the quality of suspension ointments with respect to particle size and homogeneity produced by the two types of mortars was compared. Porcelain and plastic mortars appeared equally suitable for use in the production of semisolid suspensions.

Use of QRA for decision support in the design of an offshore oil production installation

QRA is today widely used as a tool for decision support in the offshore industry. Its use has gradually changed from a prescribed analysis for verification purposes to a tool being actively used in an integrated mode. The paper describes its use in the design of a modern offshore platform. The paper addresses work methodology, selection of tools and data, organisation of QRA with other activities. Specific examples are given.

Diabetic cataract in children

PURPOSE AND METHODS

Adolescent patients with insulin-dependent diabetes mellitus (IDDM) were retrospectively analyzed for the occurrence and possible predisposing factors of diabetic cataract in a population-based series of some 600 pediatric diabetics followed up during the years 1975-1995.

RESULTS

Six patients (1%) needed cataract surgery. At the diagnosis of cataract they were 9.1-17.5 years old, and the duration of diabetes was between 0 months and 3 years 11 months. The type of cataract was similar in all patients characterized by bilateral snowflake type cortical deposits and posterior subcapsular cataract. Four of the six patients had at least a six-month history of diabetic symptoms before the treatment was started, and five patients had ketoacidosis at initial admission to hospital. In one of the 11 operated eyes diabetic retinopathy was observed immediately after surgery. Three patients developed proliferative retinopathy within 7-10 months after the operation, after 6.3-11.8 years of diabetes.

CONCLUSIONS

The prevalence of diabetic cataract was around 1% in the pediatric diabetic population. In the pathogenesis of cataract long duration of diabetic symptoms and ketoacidosis prior to the commencement of treatment may be of significance. Good metabolic control after diagnosis did not protect for cataract. Diabetic cataract can safely be treated by modern surgical techniques, but close monitoring of the fundi for retinopathy after the operation is crucial, as proliferative retinopathy may develop rapidly after cataract surgery despite relatively short duration and acceptable metabolic control of diabetes.

Retinal vasodilation and hyperglycaemia in diabetic children and adolescents

Retinal vessel diameters of 45 diabetic children and adolescents with diabetes were measured on black-and-white fundus photographs (negatives) using digital image analyses technique and microdensitometry as well as with direct micrometry. The changes in vessel diameters in two sets of photographs taken at an interval of 2.4 +/- 0.3 years were compared with glycated haemoglobin level, retinopathy status and various other parameters. During the follow-up period both arterial and venous diameters increased significantly (p = 0.0436 and p = 0.0001, respectively), but the changes in individual vessels and between patients differed markedly. The superior temporal vein dilated more than the inferior temporal vein. The average increase in venous calibre was related to the glycated haemoglobin level on the date of the second examination (p = 0.0492). Signs of early retinopathy developed more often in the eyes with venous dilation (6 of 18 eyes) than in those without (3 of 24 eyes), but the difference did not reach statistical significance. The results indicate that retinal vasodilation is associated with chronically elevated blood glucose level in diabetic children, and may precede development of other signs of retinopathy.

White spots in the central fundus in diabetic children and adolescents

Previously, small defects in the retinal pigment epithelium appearing as depigmented spots in the fundus photographs have been observed in a high proportion of adult diabetic patients. In order to evaluate whether these changes already occur in children we examined the black-and-white and colour fundus photographs of 206 diabetic children aged 4.6-19.6 years (median 12.6), with the median duration of diabetes of 4.7 years (range 0.0-14.2). Early signs of retinopathy were observed in 27 (13.1%) of them. The control group was composed of 45 healthy children aged 8.1-16.6 years (median 11.8). One or more tiny white spots in the fundus of one or both eyes were observed in 97 diabetics (47.1%), more often in those with retinopathy than in those without (66.7% vs. 44.1%, p less than 0.001). In the control group similar spots were observed in 24 children (53.5%). Only in a small proportion of children (4.4% of both diabetic and control patients) were the spots numerous. In children most of the white spots in the fundus may represent drusen type deposits rather than defects in the pigment epithelium.