S. Sindhu

The Relative Merits of Early Morning vs Random Urine Samples for Studying Crystalluria

The study of crystals in stone patients has helped to properly evaluate and treat patients with urinary stone disease (1). The relative merits of early morning urine (EMU) samples and those randomly collected are hotly debated. This paper analyzes the differences between the findings from EMU and random urine samples collected from 200 crystalluric patients.

Do Stone Formers Lack Inhibitors in Urine

Kidney stone formation may be caused by a deficiency of inhibitors usually present in urine (1). Inhibitors reported in urine are magnesium, zinc, fluoride, stannous ion, citrate, pyrophosphate, phosphocitrate, RNA, and acidic glycoprotein (2). This paper presents the findings of reduced inhibitory capacity in urine of stone patients as compared to that in urine of normal subjects.

Pyridoxine in the Long-Term Follow-Up of Crystalluric Stone Formers

The excretion of oxalic acid in the urine is significantly higher in calcium-oxalate stone formers than in healthy control subjects (1). Patients with primary hyperoxaluria also have a raised excretion of urinary oxalate. Some cases of primary hyperoxaluria respond to high doses of pyridoxine with a fall in urinary oxalate excretion to normal levels (2). The magnitude of calcium oxalate crystalluria is directly proportional to the oxalate concentration in the urine (3). This study was undertaken to determine the effect of pyridoxine on calcium oxalate crystalluria.

Growth of Uric Acid Crystals in Vitro

Very few reports are available on the growth of uric acid crystals in vitro. In this study an attempt was made to grow uric acid crystals in Hane’s tubes in modified conventional silica gel medium. 1.03g/mL density sodium meta silicate was prepared in double distilled water. Different concentrations of uric acid at 3 mg%, 4 mg%, 5 mg% and 6 mg% each were incorporated separately into the gel. The pH of each set of experiments was adjusted with 1M acetic acid to 10.5, 10, 9.5, 9, 8.5, 8, 7.5, 7, 6.5, 6 and 5.5 for each of the different concentrations of uric acid. The solutions were set aside overnight to gel. After gelatification, 5.25M (1.05g/mL density) acetic acid was added to the top of the gel. The experiment was carried out at room temperature, fridge temperature and body temperature. The tubes were examined for the time of onset of appearance of the crystals, and the size of the crystals and the rate of growth during the different times of observation, namely days 1, 3, 7, 14, 21 and 30 were assessed. The crystals were then washed, dried and subjected to light microscopy, infrared (IR) analysis and Scanning Electron MicroscoDv (SEM).

Anticalculogenic Properties of Scoparia dulcis Linn

Various plant preparations have been used for treatment of urinary stone disease, but their efficacy has not been proved. This paper attempts to scientifically study the anticalculogenic property of one such medicinal plant — Scoparia dulcis Linn. The plant extracts were prepared in acetone, petroleum ether and chloroform in concentrations of 20 mg%, 40 mg% & 80 mg% respectively. The inhibitory effects of these plant extracts were studied in calcium oxalate crystal growth in silica gel medium. The different test agents (drug in concentrations of 500 mg and 1 g/100 g rat weight), standard (hydrochlorothiazide 0.25 mg/100 g rat weight) and control (normal saline 0.91% – 2.5 mL/100 g rat weight) were administered orally to male Wistar albino rats. The urine output was recorded at 5 hours and 24 hours to study the diuretic property. Another group of rats was administered the drug in the above concentrations daily for one month and the blood was collected for biochemical estimations and compared with controls.

Oxalate Crystalluria — A Disease

Urinary crystals are the fundamental units of stone formation. Their presence indicates the process of urolithiasis. Calcium oxalate crystalluria can cause low backache, dysuria or ‘crystalgia’. This study was intended to assess whether sympotmatic crystalluria can exist alone without obvious urinary stones.

Phosphate Crystal Growth in Vitro - the Mix Up

The formation of urinary crystals is an essential step in stone disease. Hence proper understanding of these crystals and their accurate identification in tissues and body fluids is of great importance. Growth of urinary crystals in vitro has become an integral part of the study of the nucleation and growth characteristics of crystals. It is known that human urinary deposits sometimes contain struvite crystals, and study of urinary stones produced in the body has also shown newberyite crystals. We have been able to grow both struvite and newberyite in test tubes in silica gel medium. This paper details the problems encountered in growing crystals of struvite and newberyite.

Purity of Crystals Grown in Vitro in the Presence of Dopants

The addition of impurities to a crystal growth environment to alter the process of nucleation, growth and morphology of crystals is known as doping. The present study was undertaken to assess the purity of calcium oxalate monohydrate (COM) crystals when dopants are added to growth media in vitro. COM crystals were grown in Hane’s tubes using modifications of the conventional silica gel media. Pyridoxine (0.13%), allopurinol (0.33%), magnesium (5%), citrate (5%) and tartrate (5%) were added as dopants to the top solution of the crystal growth system and the rate of growth and size of crystals determined. On the thirtieth day the crystals were washed from the gel and analysed by X-ray diffraction (XRD) using an X-ray powder diffractometer (PW 1140/90 with CuK a-radiation), Scanning Electron Microscopy (SEM) and energy dispersive x-ray microanalysis (EDAX). One hundred samples were studied.

Does Ostwald Ripening of Calcium Oxalate Crystals Occur in Vitro

Ostwald ripening occurs when the smaller crystals in a crystal suspension dissolve and the released solute ions are deposited upon the larger crystals, so that the average crystal size of the suspension increases. The present study was undertaken to determine whether this process occurs in a calcium oxalate monohydrate (COM) crystal growth system in vitro. Chemically pure COM crystals were grown in Hane’s tubes in modified conventional silica gel medium utilising oxalic acid and calcium chloride as reactants, one incorporated into the gel and the other added to the top. The crystals that formed inside the gel were removed using micropipettes at different time intervals, namely, 1, 2, 3, 4, 5, 6 and 24 h. The crystals were washed and their pattern, number and size were studied under the light microscope at magnifications of 70 and 280.

Oral Citrate Therapy in Urolithiasis

Hypocitraturia is a proven risk factor in recurrent urolithiasis. Citrate in urine chelates calcium ions and reduces the amount of calcium available for oxalate stone formation, thereby lessening the chances of stone formation. This study was conducted to determine the efficacy of different oral citrate drugs in altering urinary risk factors. The aim of the study was to identify a satisfactory citrate preparation for stone patients to increase the urinary citrate level.