Quantitation of proteinuria by spot urine sampling

Few studies have shown that calculation of protein/creatinine ratio in a spot urine sample correlates well with the 24-hour urine collection. A study was conducted to compare the accuracy of a spot urinary protein/creatinine ratio (P/C ratio) and urinary dipstick (albustix) with the 24-hour urine protein (24-HUP). Fifty samples from 26 patients were collected. This included a 24-hour urine sample followed by the next voided spot sample. The protein/creatinine ratio was calculated and dipstick (albustix) was performed on the spot sample. This was compared with the 24-hour urine protein excretion. The correlation between the three samples was statistically highly significant (p=<0.001) for all levels of proteinuria. The normal value of protein/creatinine ratio in Indian children was also estimated on 100 normal children attending the OPD and was calculated to be 0.053 (S.E of mean±0.003).     

A Comparative Study of Clinical Utility of Spot Urine Samples with 24-h Urine Albumin Excretion for Screening of Microalbuminuria in Type 2 Diabetic Patients

Twenty-four hour urinary albumin excretion (UAE) is considered as gold standard method for albuminuria measurement, but collection of 24-h urine is inconvenient. The aim of present study was to evaluate whether albumin: creatinine ratio (ACR) and urinary albumin concentration (UAC) in different spot urine samples correlate or not with 24-h UAE for screening of microalbuminuria in type 2 diabetic patients. We collected first morning void (FMV), random urine sample (RUS) and 24-h urine, separately on consecutive days from 104 type 2 diabetic patients. ACR and UAC in each spot urine sample compared with 24-h UAE with regard to Pearson correlation coefficient. Pearson’s correlation of albumin: creatinine ratio (ACR) with 24-h UAE was (r = 0.802 and 0.623) in first morning void (FMV) and random urine sample (RUS), respectively. Pearson’s correlation coefficient of urinary albumin concentration (UAC) compared with 24-h UAE was (r = 0.943 and 0.920), in FMV and RUS, respectively, P < 0.01. Results revealed that values in first morning void (FMV) were better correlated with 24-h urinary albumin excretion (UAE), than the values in random urine sample (RUS). We conclude that the first morning void (FMV) may be able to replace 24-h urine collection, preferably urinary albumin concentration (UAC) in the initial screening of microalbuminuria in diabetic patients.     

Low level of adherence to instructions for 24-hour urine collection among hospital outpatients

Introduction:

We hypothesized that patients are poorly informed about proper procedure for 24-hour urine specimen collection and its relevance in determination of biochemical analytes, despite availability of leaflets and webpage with instruction for collection. The aim of this survey was to question outpatients how well are they informed about procedure of 24-hour urine specimen collection.

Materials and methods:

The survey with 10 questions was done in outpatient laboratory of University Department of Chemistry, Medical School University Hospital Sestre Milosrdnice, Zagreb, Croatia. The study included 59 patients with collected 24-hour urine sample who have consented to participate in the survey.

Results:

Out of 59 participants, most of them (0.97) were older than 40 years. Internet was not recognized as a source of information (1/59). Almost one third of the patients have changed their drinking habits to collect more urine volume. Although most of the patients (0.60) were aware that the bottle of water is the best choice for the container, almost half of them were collected urine samples in the plastic soft drink bottle. Laboratory staff and physicians often have given information about proper collection procedure, but that information was insufficient.

Conclusions:

Patients are usually not aware of importance of proper preanalytical procedure for collecting urine specimen and how improper collection could affect results of requested tests. Education of outpatients, general practitioners and laboratory staff is needed in order to improve sample quality and trueness of results.     

Incidence of microalbuminuria in hypertensive patients

The prevalence of microalbuminuria was assessed in 174 albustix negative hypertensive patients by estimating albumin in the morning random urine samples by immunoturbidimetric method within four hours of voiding of urine. The urine samples were not stored and collected without any preservatives. The urinary albumin was calculated in terms of ratio with respect to urinary creatinine and expressed as albumin creatinine ratio (mg/g). Out of 174 albustix negative hypertensives, 58 (33.3%) patients were found to have microalbuminuria. The prevalence of microalbuminuria in males and females was found to be 34% and 30.7% respectively. No correlation was found between the Body Mass Index (BMI) and albumin excretion (r² = 0.0271) and between duration of hypertension and urinary albumin excretion (r² = 0.0042). Prevalence of microalbuminuria in nonsmokers and non-alcoholic hypertensives was 20%. The prevalence in alcoholics, smokers and both smokers and alcoholics was found to be 35%, 42% and 41% respectively. The high prevalence of microalbuminuria than the various reported studies on the subject demands establishment of a screening programme for microalbuminuria, implementation of specific intervention methods and education of hypertensive patients about the consequences of smoking and alcohol on possible involvement of renal system.     

Diurnal variations and 24 hr. urinary excretion of mucoprotein and Tamm-Horsfall protein in renal stone patients

Six consecutive day and night urine samples from 25 renal stone patients and 25 comparabe controls were collected and analysed for total mucoproteins, Tamm-Horsfall mucoprotein, & creatinine. In normal subjects the 24 hour, day and night urinary excretion of mucoprotein was 101.4±34.5, 58.2±20.1 and 40.5±19.3 mg respectively. The Tamm-Horsfall mucoprotein excretion was 43.9±18.4, 21.5±8.6 and 20.6±9.9 mg in respective samples. Stone formers excreted significantly higher amount of mucoprotein but not the Tamm-Horsfall mucoprotein. Furthermore, the diurnal variations was visible only for in case of total mucoprotein in both the groups.     

Non enzymatic glycosylation of IgG and their urinary excretion in patients with diabetic nephropathy

Diabetic nephropathy is a major cause of end stage renal disease. Increased excretion of albumin has widely been recognized as an early manifestation of diabetic nephropathy particularly in subjects with diabetes mellitus. However, certain other proteins besides albumin may be excreted in high amount during early phase of diabetic nephropathy. The serum and urinary IgG, Glycosylated hemoglobin, fructosamine and glycosylated IgG were evaluated in the present study. Thirty-two patients of Type 2 Diabetes without any complications, thirty-one patients of Type 2 Diabetes with nephropathy, twenty-six patients of non-diabetic nephropathy and forty normal healthy individuals were enrolled in this study. Subjects were grouped based on their serum creatinine level. Serum IgG, glycosylation of IgG and urinary IgG excretion were increased significantly in diabetic patients compared to healthy controls, which were further increased significantly in chronic renal failure patients with respect to the clinical stage of nephropathy. A positive correlation was observed between glycosylation of IgG and IgG excretion (R²=0.5995, 0.7114 respectively) in diabetic patients without any complications and diabetic nephropathy patients only, suggesting a significant role of IgG glycosylation in the vascular clearances of IgG during diabetic nephropathy.     

Evaluation of urinary abnormalities in nephrolithiasis patients from Marathwada region

Urinary abnormalities were evaluated in 100 renal stone patients with first episode of renal stone having age 22 to 45 years from both sex and compared to 100 normal healthy control group having same age group from both sex. Twenty-four hours urinary oxalate, calcium, uric acid, sodium, magnesium, phosphorus and citrate were estimated. The urinary pH was also determined. In stone formers urinary oxalate, calcium, sodium and uric acid excretions were significantly higher when compared with control group. Whereas citrate, phosphate and magnesium excretion were significantly lower in stone formers when compared with control. The pH of urine in stone formers was lower than the controls. High dietary intake of purine rich diet causes elevated excretion of uric acid, which leads to calcium oxalate crystal formation and precipitation. Other risk factors such as urinary oxalate, calcium also related to formation of renal calculi. Hypocitraturia is the main cause of renal calculi along with hypomagnesiuria and hypophosphaturia in the patient of Marathwada region. On the basis of urinary abnormalities further stone formation in the patient can be prevented by dietary modifications.     

Urinary N-acetyl beta glucosaminidase and gamma glutamyl transferase as early markers of diabetic nephropathy.

Albumin and enzymes-N-acetyl-beta-glucosaminidase (NAG) and gamma glutamyl transferase (GGT) were estimated in the morning random urine samples of 196 albustix negative diabetic patients to evaluate the clinical utility of these urinary enzymes as early markers of diabetic nephropathy. Albumin was estimated by immunoturbidimetric method and enzymes by linetic essay within six hours of voiding of urine. The urinary albumin and urinary enzyme concentration was calculated in terms of ratio with respect to urinary creatinine. Correlation coefficient (r) bewween urinary albumin and urinary enzymes in normoalbuminuric, microalbuminuric and overall diabetic cases was 0.23, 0.32 and 0.40 respectively for NAG, and 0.08, 0.06 and 0.18 respectively for GGT. NAG excretion was found increased in 34%, 63.7% and 49.5% of normoalbuminuric, microalbuminuric and overall diabetic cases respectively while GGT in 6.4%, 24.5% and 15.8%. The correlation coefficient between urinary albumin and NAG in normoalbuminuric, microalbuminuric, and overall diabetic patients with increased NAG excretion was found only 0.31, 0.27 and 0.35 respectively. No correlation was found between duration of diabetes and enzyme excretion. The study suggests that urinary NAG or GGT or both together do not have any clinical significance as an early marker of diabetic nephropathy.     

Effect of Oestrogen on Altering the Serum and Urinary Levels of Calcium,Phosphate and Magnesium in Hysterectomised Women Compared to Natural Menopausal South Indian Women: A Case Control Study

Given the paucity of studies conducted to know the effect of suddenness and earlier onset of endocrinological changes associated with hysterectomy, on the serum and urinary levels of calcium, magnesium and phosphate the present study was conducted to compare the levels of calcium, magnesium and phosphate in serum and urine of hysterectomised and natural menopausal south Indian women. This is a cross-sectional observational study. The study included three groups of 30 healthy premenopausal, 30 early surgical menopausal and 30 natural post menopausal women. Women suffering from any endocrine disease were excluded. Analysis was performed in serum and urine sample. The levels of calcium, magnesium and phosphate in serum and calcium/creatinine, magnesium/creatinine and phosphate/creatinine ratio were estimated in urine by spectrophotometric method. Hysterectomised women (serum calcium: 8.7 ± 0.09 mg/dl; urine calcium/creatinine: 0.16 ± 0.02) have significantly low serum calcium (p < 0.001) and high urinary calcium/creatinine (p = 0.002) ratio and post menopausal women (serum magnesium: 2.1 ± 0.03; serum phosphate: 4.4 ± 0.16; urinary calcium/creatinine: 0.17 ± 0.02; urinary magnesium/creatinine: 0.09 ± 0.01) have significantly high serum magnesium (p = 0.016), serum phosphate (p = 0.043) and high urinary calcium/creatinine (p = 0.002), magnesium/creatinine ratio (p = 0.025) compared to healthy pre menopausal women. Post menopausal women (serum calcium: 9.1 ± 0.08) have significantly high serum calcium and phosphate compared to hysterectomised women (serum phosphate: 3.93 ± 0.11). Hysterectomised women have significantly low serum calcium, oestrogen and high urinary calcium/creatinine ratio compared to healthy premenopausal women and low serum calcium and low serum phosphate compared to natural postmenopausal women. Natural postmenopausal women had low serum oestrogen and high serum magnesium, serum phosphate, urinary calcium creatinine ratio and urinary magnesium creatinine ratio compared to healthy premenopausal women.     

我国科技期刊刊群实现形态和路径研究

[目的]归纳科技期刊刊群实现形态和实施路径,为我国科技期刊刊群建设提供参考。[方法]使用网站调研、文献调研、访谈调研和案例研究等方法,全面搜集国内外现有科技期刊刊群资料,归纳和分析刊群的存在形态和发展路径。[结果]科技期刊刊群实现模式可以分为学科刊群、学协会刊群、出版社或公司运营刊群、内容集成商刊群及网络聚合刊群模式。刊群建设路径可以分为孵化式、复制式、加盟式、改造式及整合式路径。[结论]针对不同的刊群实现模式需要有对应的建设路径,并遵循一定的建设原则,从平台、品牌、产品、服务等方面加以保障。     

Term norm distribution and its effects on Latent Semantic Indexing

Latent Semantic Indexing (LSI) uses the singular value decomposition to reduce noisy dimensions and improve the performance of text retrieval systems. Preliminary results have shown modest improvements in retrieval accuracy and recall, but these have mainly explored small collections. In this paper we investigate text retrieval on a larger document collection (TREC) and focus on distribution of word norm (magnitude). Our results indicate the inadequacy of word representations in LSI space on large collections. We emphasize the query expansion interpretation of LSI and propose an LSI term normalization that achieves better performance on larger collections.     

Assessment of renal acidification capacity of stone formers by acid challenge test

Acid challenge test was carried out on 87 subjects (37 normal and 50 radiologically proven stone formers) to assess their renal acidification capacity. NS were given three doses viz. 75, 100 and 150 mg NH₄Cl/Kg body weight while the SF were tested with only 150 mg dose which was found to be an adequate dose. Ammonium chloride was given in gelatin capsules with breakfast and hourly urine samples were collected for next 7 hours. pH, creatinine, calcium, inorganic phosphorus, citrate, titrable acid and ammonium were analysed in all the samples. The incidence of renal tubular acidosis (RTA) in NS, tested with 75 mg and 100 mg/kg doses of ammonium chloride, was 50% and 10% respectively while it was nil and 24% respectively in NS and SF tested with 150mg/kg dose. Complete RTA was detected in one SF. No significant difference was observed in urinary profile of NS and SF except that the hourly titrable acid excretion was lower in later. A comparison between with and without RTA SF revealed that titrable acid and phosphate excretion decreased in RTA defect. Overall data indicate that (a) RTA was an etiologic factor in one fourth of the SF; (b) an oral acid challenge test is a good adjunct to detect this condition and (c) acid challenge increases calcium, phosphate and titrable acid excretion and decreases citrate.     

The use of lysosomal enzymuria in the early detection and monitoring of the progression of diabetic nephropathy

Recent acquisitions on the early detection and monitoring of the progression of diabetic complications (nephropathy) using the techniques of enzymology (lysosomal enzymes) are reviewed. it appears that the kidney is the principal source of urinary lysosomal enzymes. Urinary samples for lysosomal enzyme determination can be either 24-hour or spot-collection. The use of synthetic substrates (4-methylumbelliferyl substrates) provides an easy, inexpensive, sensitive and highly reproducible method of lysosomal enzyme assay. It is recommended that more than one enzyme be assayed in the process. The use of fractional enzyme excretion (FEE) ratios is further recommended. The urinary lysosomal glycosidases investigated and found to be of particular diagnostic value in the early detection of diabetic nephropathy include N-acetyl-β-D-glucosaminidase (β-hexosaminidase, NAG), β-glucuronidase and β-galactosidase, with NAG being the most useful indicator. Urinary NAG can be used in monitoring the progression of diabetic nephropathy. The fluorimetric assay of lysosomal glycosidases is particuarly recommended in developing countries since it is simple, sensitive and inexpensive.     

Correlation between Apgar score and urinary uric acid to creatinine ratio in perinatal asphyxia

A randomized case control hospital based study was conducted over 12 months time on 31 asphyxiated and 31 normal newborn to see whether urinary uric acid can be used as a marker of perinatal asphyxia and can be correlated with the clinical diagnosis by Apgar score. Uric acid and creatinine were estimated in spot urine within 24 hours after birth in both cases and controls. A ratio between concentrations of uric acid to creatinine was estimated and compared between cases and controls. It was found that the ratios were significantly higher in cases than controls (3.1± 1.3 vs 0.96± 0.54; P < 0.001) and among asphyxia patients, a significant negative linear correlation was found between the uric acid to creatinine ratio and the Apgar score (r = −0.857, P < 0.001). So urinary uric acid to creatinine ratio can be used as an additional non-invasive dispace, easy and at the same time early biochemical marker of birth asphyxia which biochemically supports the clinical diagnosis and severity grading of asphyxia by Apgar score.     

Parathyroid and Calcium Status in Patients with Thalassemia

Thirty patients with thalassemia major receiving repeated blood transfusion were studied to see their serum parathyroid hormone (PTH) and calcium status. Serum PTH, serum and 24 h urinary calcium, and serum alkaline phosphatase, phosphorus, and albumin-corrected calcium levels were determined. Half of these patients, in addition to transfusion, were also supplemented with vitamin D (60,000 IU for 10d) and calcium (1500 mg/day for 3 months). Serum PTH, and serum and 24 h urinary calcium concentrations of the patients receiving transfusions were found to be significantly reduced while their serum alkaline phosphatase, phosphorus, and albumin-corrected calcium levels were not significantly altered when compared to the respective mean values for the control group. Vitamin D and calcium supplementation significantly increased their serum PTH and calcium levels. Supplementations also increased urinary excretion of calcium. The results thus suggest that patients with thalassemia have hypoparathyroidism and reduced serum calcium concentrations that in turn were improved with vitamin D and calcium supplementation.     

N-acetyl-β-D-glucosaminidase,alanine aminopeptidase and protein: Creatinine ratio as early indicators of diabetic microangiopathy

The urinary excretion patterns of N-acetyl-β-D-glucosaminidase (NAG), alanine aminopeptidase (AAP) and protein/creatinine ratio (UP/UCR) were studied in 133 diabetic subjects under treatment, 7 patients with established diabetic nephropathy (DN) and 79 carefully selected (age-matched) healthy subjects. NAG, AAP and UP/UCR were highly elevated in DN, while in diabetics urinary NAG levels correlated well with the degree of long-term metabolic control indicated by glycosylated hemoglobin (GHB or Hba1). Both AAP and UP/UCR were found to be more sensitive than NAG, but less specific. Urinary NAG and AAP assays thus offer simple, sensitive and non-invasive techniques for prognostic indication of the onset of microangiopathic changes in long-term diabetic subjects.     

Effect of Antiresorptive Therapy on Urinary Hydroxyproline in Postmenopausal Osteoporosis

Osteoporosis becomes a serious health threat for older postmenopausal women by predisposing them to an increased risk of fracture. Osteoporosis and associated fractures are an important cause of morbidity and mortality. Special attention is being paid to early detection, management, and treatment of postmenopausal osteoporosis in women. Biochemical markers can enable dynamic and rapid measurement of total body skeletal metabolism and will be clinically useful in the management of postmenopausal osteoporosis women (PMO) and also for assessing the effects of antiresorptive therapy. With this view, we planned to assess osteoclastic activity by determining urinary hydroxyproline in osteoporotic women. The aim of this study is to measure urinary hydroxyproline (expressed as mg of hydroxyproline/g of creatinine) and serum ascorbic acid in postmenopausal women with osteoporosis and without osteoporosis. These biochemical parameters were determined 3 months post antiresorptive therapy (alendronate + calcium + vitamin D) in postmenopausal osteoporosis patients. 60 postmenopausal women with osteoporosis in the age group 45–60 years and 60 healthy postmenopausal women (normal bone mineral density) in the same age group were included in the study. Urinary hydroxyproline levels were significantly increased (P < 0.001) in PMO at baseline level as compared to control group. These levels were decreased significantly (P < 0.001) post therapy in PMO patients. Serum vitamin C levels were significantly decreased (P < 0.001) in PMO patients at baseline level as compared to controls. No significant change occurred of serum vitamin C level post therapy. Raised excretion of hydroxyproline at the baseline level might be due to increased degradation of collagen type I from the bone matrix in osteoporosis. Breakdown of collagen seems to be lowered as reflected by lowering of hydroxyproline excretion post antiresorptive therapy. Alteration in the concentration of this marker can be very well utilized to monitor the effectiveness of therapy. Thus simple, direct urinary assay to measure bone resorption is very useful in monitoring the therapy in PMO and may become an integral part of the management of osteoporosis.     

Urinary calcium excretion and its response to oral calcium loading in normal subjects and stone formers

Ten normal subjects (NS) and 28 stone formers (SF) underwent 1 and 2 gm. calcium loading test following three days of calcium restricted diet (400 mg/day). On 4th day first 24-hr. urine sample was collected. An additional 1 and 2 gm. of calcium (Calcium gluconate) was given orally on 5th and 6th day respectively and 24-hr. urine samples were collected on both the days. Before loading, all the NS had normal calcium excretion (<200 mg/day). Calcium loading caused hypercalciuria in 10% and 20% cases respectively. Among SF, 17.9% cases were already hypercalciuric and calcium loading increased it to 42.9% and 46.4% patients respectively. The results indicated that exogenous calcium had only limited capacity to increase urinary calcium and that the magnitude of rise was relatively higher in SF. The increased excretion in SF was primarily due to intestinal hyperabsorption of calcium.     

国内外学术期刊论文更正研究的现状与特点

【目的】梳理国内外学术期刊论文更正的研究发展脉络,以期为今后的相关研究提供借鉴和参考。【方法】 采用文献调研法,通过调研国内外有关期刊论文更正的研究文献,对比分析国内外研究的现状与特点。【结果】分析发现,国内外对该问题的研究文献有限,就目前仅有的研究文献来看,国内研究的视野较窄,局限于从期刊自身建设的角度进行探讨,国外则站在更高的角度,从学术界加强科研自律、加强科研道德规范的角度予以研究。此外,截止目前的研究都只关注到更正行为本身,而并未对更正行为产生的更正文献有所关注。【结论】在今后的研究中,应加强对更正文献的关注,积极探索和挖掘更正文献本身的价值和影响力,以呼吁学术界对更正文献的关注和重视。     

Compliance of self-measured HRV using smartphone applications in collegiate athletes

PurposeWith the continued rise of technology in sports, many innovations have been made with smartphone applications designed to measure physiological fatigue and recovery. However, the proper methodology and potential pitfalls for long-term monitoring have not been fully explored. Therefore, this study aimed to observe compliance rates of self-measured daily heart rate variability (HRV) recordings in collegiate athletes from two different sports teams throughout their competitive seasons.MethodsSixteen male hockey players and forty-seven female rowers participated in this study. Daily HRV measurements were collected over 17 weeks. Athletes were categorized as Compliant or Non-compliant based on a 43% compliance rate threshold.ResultsOf the 16 hockey players, all were above the 43% threshold and considered Compliant. As a team, weekly compliance rates varied throughout the data collection reaching a high of 99.11% and a low of 37.50%. Of the 47 rowers, 26 athletes were categorized as Compliant while the remaining 21 athletes were categorized as Non-compliant, falling below the 43% threshold. As a team, weekly compliance rates varied throughout the data collection reaching a high of 70.81% and a low of 8.70%.ConclusionsSmartphone-derived measures of HRV are valid and reliable tools for assessing training status and recovery in athletes. New applications provide a practical means for obtaining daily recordings. However, longitudinal monitoring of team-sport athletes may be difficult due to decreases in compliance. Coaches and practitioners should have plans in place to keep athletes actively involved in data collection with effective communication and proper explanation of the importance of the measures being taken.