Neuronal cell death in scrapie-infected mice is due to apoptosis

Neuronal loss is a salient yet poorly understood feature in the pathology of transmissible spongiform encephalopathies (prion diseases). Cell culture experiments with neurotoxic prion protein fragments suggest that neuronal cell death in these diseases may be due to apoptosis. To test this hypothesis in vivo we used the in situ end-labeling (ISEL) technique and electron microscopy to study cell death in an experimental scrapie system in the mouse. ISEL, which relies on the incorporation of labeled nucleotides in fragmented DNA by terminal transferase, showed labeled nuclei in the brains and retinae of mice infected with the 79A strain of scrapie, whereas no labeling was observed in control animals. In the retina the highest numbers of labeled nuclei were found in the outer nuclear layer 120 days post infection followed by massive cell loss in this layer. In the brain, labeled nuclei were mainly found in the granular layer of the cerebellum of terminally ill mice. This corresponded to the presence of small dark nuclei with condensed and occasionally fragmented chromatin at the light and electron microscopical levels. Our results support the hypothesis that neuronal loss in spongiform encephalopathies is due to apoptosis. This may explain the almost complete absence of inflammatory response in prion diseases in the face of widespread neuronal cell death, and may also have therapeutic implications in the future.

Renal mass and serum calcitriol in male idiopathic calcium renal stone formers: role of protein intake

To determine whether chronic overconsumption of protein might increase renal mass and cause up-regulation of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D] production, 57 male recurrent idiopathic calcium stone formers (RCSF), 29 with hypercalciuria (HCSF; urinary calcium x V, > 7.50 mmol/day) and 28 with normocalciuria (NCSF), were compared with 15 healthy male controls (C) while consuming a free choice diet. Renal mass in RCSF was measured by the sum of the surface areas of right and left kidneys (square centimeters) on plain films of the abdomen by a computer-assisted sonic stylus; in C, renal mass was assessed sonographically. Serum intact PTH and 1,25-(OH)2D were measured radioimmunometrically. In HCSF, urinary phosphate x V (35.9 +/- 1.2 mmol/day) was higher than that in NCSF (29.3 +/- 1.3 mmol/day; P = 0.0009) or C (28.7 +/- 1.8 mmol/day; P = 0.005); urinary creatinine x V (16.5 +/- 0.5 mmol/day) was also higher in HCSF than in NCSF (15.0 +/- 0.5 mmol/day; P = 0.024) or C (13.8 +/- 0.6 mmol/day; P = 0.002). For identical blood levels of ionized calcium and phosphate, the 1,25-(OH)2D/PTH concentration ratio (an index of regulation of 1,25-(OH)2D production) was higher in HCSF (6.5 +/- 1.0) than in NCSF (4.0 +/- 0.3; P = 0.005). In addition, the sum of the surface areas of right and left kidneys was increased in HCSF (163.4 +/- 2.9 cm2) compared with that in NCSF (140.5 +/- 3.1 cm2; P = 0.0001), and it positively correlated with urinary phosphate x V (r = 0.429; P = 0.001) as well as with urinary creatinine x V (r = 0.294; P = 0.026); no such correlation was noted in C. Calcitriol levels were positively related to renal mass in RCSF (r = 0.316; P = 0.018), but not in C. Finally, urinary calcium x V positively correlated with the serum calcitriol/PTH concentration ratio only in RCSF (r = 0.388; P = 0.003). These findings suggest that protein overconsumption may cause an increase in renal mass and up-regulate calcitriol production in some male RCSF, an effect that would subsequently cause "idiopathic" hypercalciuria.

[Sulfadiazine nephrolithiasis and nephropathy]

Sulfadiazine-nephropathy and -nephrolithiasis were well known complications of high dose sulfadiazine therapy 50 years ago. In the last few years high dose sulfadiazine therapy has been widely used for treatment of toxoplasmic encephalitis in AIDS patients. As a consequence sulfadiazine-nephropathy and -nephrolithiasis have become increasingly common. We describe 2 patients with the typical picture of these complications. Therapy is based on the fact that the solubility of sulfadiazine and its acetylated metabolite are markedly improved at higher urine-pH levels. Urine alkalinization is also effective for prophylaxis during sulfadiazine treatment. We present our guidelines for prophylaxis and treatment of these complications.

Infection-induced stone formation in a renal allograft

Stone formation is an uncommon complication in renal allograft recipients. We report a 61-year-old woman who had undergone cadaveric renal transplantation in 1982 because of chronic renal failure due to polycystic kidney disease. Since 1985 she has developed recurrent urinary tract infections with Proteus mirabilis, and persistent microhematuria was detectable from 1988 on. Since renal function remained stable, she was repeatedly treated with antibiotics. Following a septicemia with P mirabilis, a staghorn calculus was discovered and was surgically removed from the allograft. Stone analysis (infrared spectrometry) revealed 60% struvite and 40% carbonate apatite. Since urinary tract infections with urea-splitting bacteria are a more frequent cause of stone formation in transplant patients than in nontransplant patients with kidney stones, stone disease should be considered in every allograft recipient presenting with recurrent urinary tract infection and microhematuria.

Low bone mass in idiopathic renal stone formers: magnitude and significance

To assess bone mineral density (BMD) in idiopathic calcium nephrolithiasis, dual-energy x-ray absorptiometry was performed at lumbar spine, upper femur (femoral neck, Ward's triangle, and total area), distal tibial diaphysis, and distal tibial epiphysis in 110 male idiopathic calcium stone formers (ICSF); 49 with and 61 without hypercalciuria on free-choice diet). Results were compared with those obtained in 234 healthy male controls, using (1) noncorrected BMD, (2) BMD corrected for age, height, and BMI, and (3) a skeletal score based on a tercile distribution of BMD values at following four sites: lumbar spine, Ward's triangle, tibial diaphysis, and tibial epiphysis. After correction, BMD--and therefore also skeletal score--tended to be lower in the stone formers than in controls at five of the six measurement sites, that is, lumbar spine, upper femur, Ward's triangle, tibial diaphysis, and tibial epiphysis, limit of significance being reached for the last two sites without difference between hypercalciuric (HCSF) and normocalciuric stone formers (NCSF). Estimated current daily calcium intake was significantly lower in patients (616 +/- 499 mg/24 h, mean +/- SEM) than in controls (773 +/- 532, p = 0.02). Of 17 patients who in the past had received a low-calcium diet for at least 1 year, 10 had a low skeletal score (4-6) whereas only 1 had a high score (10-12; p = 0.037). Of the 12 stone formers in the study with skeletal score 4 (i.e., the lowest), 8 had experienced in the past one or more fractures of any kind versus only 19 of the remaining 77 patients with skeletal score 5-12 (p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Behavioral assessment of aging in male Fischer 344 and brown Norway rat strains and their F1 hybrid

Male Fischer-344 (F344) and Brown Norway (BN) rats 7-, 13-, and 24-month-old and their F344 x BN hybrid (F1) 7-, 13-, 24- and 31-month-old were tested in a behavioral battery (15-min and 24-h locomotor activity, inclined screen, rod suspension, rotorod, shock-motivated learning in a straight runway and 14-unit T maze). Necropsy was performed 3 days later and the results rated for pathology (i.e., severity of lesions observed). Age-related performance declines were observed in all behavioral tests except 15-min locomotor activity. Strain effects were observed in 15-min (BN more active than F344 and F1) and 24-h locomotor activity test (F344 more active than BN and F1 strains); rotorod performance (F344 fell more than BN and F1); and in all measures [errors (E), runtime (RT)], shock frequency (SF), and duration (SD)] in the 14-unit T maze (F344 worse than BN, BN worse than F1). T maze performance of 31-month-old F1 rats was deficient in RT, SD, and SF but E performance was equivalent to that of 7-month-old F1 rats. In a second experiment, only 7- and 31-month-old F1 rats were tested in the 14-unit T maze and the results obtained in Experiment 1 were replicated. Gross necropsy revealed age and strain effects in the number of lesions observed and the mean ratings of pathology. The 24-month-old F344 rats exhibited the greatest number of lesions and had the highest ratings (generally observed as chronic nephrosis and enlarged spleens characteristic of mononuclear cell leukemia). BN rats exhibited a high incidence of hydronephrosis at all age levels. While experiencing less obvious pathology, F1 rats experienced a significant number of lesions in the 31-month-old group. Pathology ratings correlated with behavioral performance but only for a few tests (e.g., SD and RT in 14 unit T maze in 24-month-old F344). Thus, behavioral performance declined with age and the battery of tests differentiated between the strains tested (in general, F344 worse than BN; BN worse than F1). The correlation of pathology ratings at gross necropsy with behavior did not appear to be systematic, suggesting that morbidity was not responsible for the age-related performance declines. However, more extensive evaluation of the relationship of age-related changes in health status to behavior with larger samples of rats is suggested.

[Assessment of parathyroid gland function: predictive value of a nomogram]

Recent developments in measurement of intact parathormone (PTH) has enabled to generate a nomogram for parathyroid function. Blood levels of PTH can thus be interpreted in relation to calcemia. Intact PTH and calcium were assayed in blood from 99 healthy subjects studied under fasting conditions; 26 subjects were also studied during hyper- and hypocalcemia, induced by calcium and EDTA infusions, respectively. Serum levels of intact PTH which had been obtained in 99 patients were then analysed retrospectively by comparison with the nomogram. Patients whose intact PTH levels lie above the normal zone of the nomogram produce too much PTH relative to the blood calcium level (hyperparathyroidism); those falling under the normal zone produce too little (hypoparathyroidism).

Structure of the mouse arylsulfatase A gene and cDNA

The murine arylsulfatase A (ARSA) gene and cDNA have been cloned and sequenced. The gene is 3.8 kb long and contains eight exons. All intron/exon splice junctions conform to the GT/AG consensus sequence. The genomic structure is similar to that of the human gene. One major RNA species of 3.2 kb is transcribed. This RNA species has a 5' untranslated region of 638 nucleotides and terminates in a region around nucleotide 700 downstream of the termination codon. In addition, a rare mRNA species terminating at a polyadenylation signal 135 nucleotides downstream of the termination codon has been found. A larger transcript of 4 kb can be detected in liver. The size difference is due to initiation of transcription 5' of the cap site of the 3.2-kb mRNA species. The entire ARSA cDNA has been cloned by PCR from reverse-transcribed RNA. The coding sequence has 1518 nucleotides and predicts a protein of 506 amino acids. The nucleotide as well as the amino acid sequence is highly conserved among humans and mice.

Risk factors for low urinary citrate in calcium nephrolithiasis: low vegetable fibre intake and low urine volume to be added to the list

Risk factors for low urinary citrate excretion were assessed in 34 consecutive male recurrent idiopathic calcium stone formers (RCSF) who collected two 24-h urines while on free-choice diet. Overt hypocitraturia (hypo-cit) was defined as UCit x V < 1.70 mmol/day, and 'low' citraturia (low-cit) as UCit x V between 1.70 and 2.11 mmol/day. Twenty-three RCSF had normocitraturia (normo-cit), six low-cit and five hypo-cit. UCit x V positively correlated with urine volume (VOLUME, r = 0.44, P = 0.009), vegetable fibre intake (fibers, r = 0.46, P = 0.009) and GI-alkali absorption (alkali, r = 0.47, P = 0.006), and volume, fibres and alkali tended to be lower among RCSF with low-/hypo-cit. A 3-day NH4Cl loading test (0.95 mEq/kg BW daily in 3 doses) was performed in RCSF as well as in 14 age-matched healthy male controls (C). On a plot of urine pH versus serum bicarbonate, 10 of 11 RCSF with low-/hypo-cit, but only six of 23 with normo-cit (P = 0.0004) fell off the normal range, indicating incomplete RTA. Two or more risk factors simultaneously occurred in only four of 23 RCSF with normo-cit, but in eight of 11 with low-/hypo-cit (P = 0.002). In conclusion, incomplete RTA is the most prevalent risk factor for low-/hypo-cit in RCSF, and decreases in vegetable fibres and urine volume emerge as two new risk factors for low urinary CIT.

Citrate and calcium effects on Tamm-Horsfall glycoprotein as a modifier of calcium oxalate crystal aggregation

We measured the effects of Tamm-Horsfall glycoprotein (THP) on calcium oxalate monohydrate (COM) crystal aggregation (Ac) in vitro as well as intrinsic viscosities (Vi) of THP at pH 5.7 and 200 mM NaCl and studied the effects of calcium and citrate on these parameters. THP were isolated from 24-h urines of seven male recurrent calcium stone formers (RCSF) and eight age-matched male healthy volunteers (N, normal). At basal conditions, RCSF-THP inhibited Ac by 28 +/- 10% and normal THP by 60 +/- 6% (P = 0.028). In the presence of calcium, increasing THP concentrations from 16 to 28 and 40 mg/l progressively lowered inhibition by RCSF-THP, but not by N-THP. At 40 mg/l, inhibition by N-THP was 27 +/- 9% vs. -43 +/- 8% by RCSF-THP (P = 0.001), i.e., all stone former THP promoted Ac. With an additional 3.5 mM of citrate, inhibition of Ac was 56 +/- 5% by normal and 34 +/- 6% by stone former THP (P = 0.021), and all seven stone former THP again inhibited Ac. Vi of RCSF-THP was higher than that of N at basal conditions (162 +/- 21 vs. 93 +/- 15 ml/g, P = 0.021) and in the presence of 5 mM calcium (352 +/- 54 vs. 118 +/- 17 ml/g, P = 0.001), i.e., RCSF-THP were more self-aggregated, but not when citrate was added (185 +/- 29 vs. 123 +/- 19 ml/g). (ABSTRACT TRUNCATED AT 250 WORDS)

Tubulointerstitial nephropathy persisting 20 months after discontinuation of chronic intake of germanium lactate citrate

Two young human immunodeficiency virus (HIV)-infected patients, a 25-year-old woman and a 26-year-old man, consumed large amounts of germanium lactate citrate 18% as an "immunostimulant" for 9 months. The woman, who had stage II HIV infection, developed severe renal dysfunction (creatinine clearance, 7 mL/min/1.73 m2) and slight proteinuria (0.28 g/d) after ingesting 260 g germanium lactate citrate 18%. Hepatomegaly with liver dysfunction (SGOT, 102 U/L; gamma-glutamyl transferase (GT), 159 U/L) and lactic acidosis (plasma lactate, 7.3 mmol/L) developed simultaneously. Renal biopsy revealed tubulointerstitial nephropathy with vacuolar cell degeneration and periodic acid-Schiff-positive intracellular deposits mainly in distal tubules. Liver biopsy disclosed severe hepatic steatosis; liver function tests returned to normal within 5 weeks. Since renal failure persisted for 2 years after ingestion of germanium (creatinine clearance, 14 mL/min/1.73 m2; proteinuria, 0.84 g/d), a second renal biopsy was performed, which showed marked but focal distal tubular atrophy and slight interstitial fibrosis. The male patient, who had stage III HIV infection, had ingested the same compound; he presented with a creatinine clearance of 43 mL/min/m2 and proteinuria of 0.36 g/d. Renal biopsy disclosed tubulointerstitial changes similar to those found in the female patient. After 9 months off germanium, creatinine clearance remained unchanged. Neutron activation analysis of all biopsy specimens in both cases documented germanium concentrations 10 to 70 times normal in renal tissue and 140 times normal in liver tissue.

The tale of parathyroid function in idiopathic hypercalciuria

At the origin, idiopathic hypercalciuria has been described as a syndrome consisting of normocalcemia, low plasma phosphate levels and abnormally high urinary calcium excretion. The cause of this syndrome was subject to many investigations throughout the years. Two main pathophysiologic hypotheses have been proposed: a) primary intestinal hyperabsorption of calcium, leading to depression of parathyroid hormone (PTH) secretion ("absorptive" hypercalciuria); and b) primary renal tubular leak of calcium which stimulates PTH secretion (secondary hyperparathyroidism). Most of the published studies indicate that intestinal hyperabsorption of calcium with subsequent relative hypoparathyroidism is the primary event causing idiopathic hypercalciuria, and that this occurs as a consequence of increased production of 1,25(OH)2-vitamin D3 (calcitriol). Fasting hypercalciuria, originally taken as evidence for a "renal leak" of calcium, appears to be, at least in part, the consequence of relative hypoparathyroidism.

Electron Density Distributions and Atomic Charges

Accurate electron densities and X-ray form factors of Li, Be, F and their ions have been calculated. Electron correlation, crystal fields and ionic charge transfer change the form factors by up to a few percent, mainly in the range of sin θ/ λ < 1/3 Â -1 . Although electron correlation and crystal fields are small perturbations, their effects on the density and form factor are not additive. Densities or form factors of atomic and ionic systems are very similar; [Li0F0] and [Li+F-] procrystals differ by an effective charge transfer of not more than 0.4 e. Charge transfer and charge overlap in crystals cannot be distinguished uniquely. When the experimental data on Li2BeF4 (approximately reproduced by 3/4 atomic plus 1/4 ionic procrystal) are interpreted from the atomic partial charges are as low as 0.1 e (Li+ 0.12Be+ 0.2F- 0.14); when interpreted from the ionic viewpoint,the charges are much higher, namely 0.7 e. Intermediate viewpoints are also possible.

[Urinary specific gravity--comparative measurements using reagent strips and refractometer in 340 morning urine samples]

The specific gravity of urine (SG) indicates the number and weight of solute particles in urine; its measurement is helpful in interpreting proteinuria detected by dipstick tests and in monitoring adequate hydration in patients with nephrolithiasis. Four methods for measuring SG or osmolality of urine are currently available (depression of the freezing-point, urometry, refractometry, cation exchange on a reagent strip). Using a recently developed reagent strip, we have measured SG in morning urines of 340 non-selected outpatients and compared the results with SG measurements by refractometry of the same urines. In 86.2% of all urines, a good positive correlation between SG measured by reagent strip and refractometry was noted (r = 0.913, p = 0.0001). In 13.8% of the urines, however, the SG measured by reagent strip deviated by more than +/- 5 from the value obtained by refractometry; in 90% of these urines, glucosuria (reagent strip values too low or too high), proteinuria (values too high), or bacteriuria/leukocyturia (values too low or too high) could be found. In alkaline urine (pH > 7.0), SG values obtained by reagent strip have to be corrected by +5.

Relative hypoparathyroidism and calcitriol up-regulation in hypercalciuric calcium renal stone formers--impact of nutrition

The issue of secondary hyperparathyroidism in idiopathic hypercalciuria (IH) was addressed in 61 male idiopathic calcium stone formers (SF) who underwent metabolic evaluation on a free-choice diet as well as bone mineral density (BMD) measurements by dual-energy X-ray absorptiometry. They were divided into hypercalciurics (HCSF, n = 30, UCa X V > 7.5 mmol/day) and normocalciurics (NCSF, n = 31, UCa X V < 7.5 mmol/day). At identical blood Ca2+ levels, parathyroid hormone (PTH) was lower in HCSF (25.3 +/- 1.8 pg/ml) than in NCSF (31.4 +/- 1.8 pg/ml, p = 0.017). Since neither fasting urinary hydroxyproline nor pyridinoline/deoxypirdinoline excretions nor BMD values were different between HCSF and NCSF, chronic bone dissolution as the cause of relative hypoparathyroidism in HCSF could be excluded. Despite lower PTH in the face of similar phosphate, Ca2+ and IGF-1 blood levels, however, serum 1,25-dihydroxyvitamin D3 (calcitriol) concentrations were slightly (though not significantly) higher in HCSF than in NCSF (52.8 +/- 3.2 vs. 47.3 +/- 2.9 pg/ml, p = NS), and calcitriol/PTH ratio was elevated in HCSF (2.52 +/- 0.29) vs. NCSF (1.66 +/- 0.15, p = 0.001). Creatinine clearance, significantly higher in HCSF than in NCSF (113 +/- 4 vs. 92 +/- 3 ml/min/1.73 m2, p = 0.0001), was positively correlated with excretion rates of urinary markers of both protein and NaCl intake. Since serum calcitriol levels were positively correlated with creatinine clearance (r = 0.350, slope = 0.288, p = 0.006), up-regulation of calcitriol synthesis with subsequent relative hypoparathyroidism in HCSF is-at least partly-explained by exaggerated protein and sodium consumption.

Chromophore of sensory rhodopsin II from Halobacterium halobium

The photoreceptor sensory rhodopsin II (sR-II) was enriched 120-fold from cell membranes of Halobacterium halobium. The final preparation yields sR-II with a specific content of 3 nmol of sR-II/mg of protein. The spectroscopic measurements were performed on the enriched photoreceptor solubilized in digitonin. In the absolute absorption spectrum of the partially purified receptor, the main peak in the visible range corresponded to sR-II with a maximum at 488 nm. Cytochromes contributed to the spectrum only in a minor band at 415 nm. The extinction coefficient of sR-II was estimated from difference spectra during bleaching with hydroxylamine to be 48,000 M-1 cm-1. The reduced chromophore displayed a pronounced fine structure which is due to the coplanarity of the retinyl residue. The isomeric composition of the chromophore from the enriched photoreceptor was determined in retinal extracts in HPLC. The dark-adapted sR-II contains 80% all-trans- and 20% 13-cis-retinal. After illumination, the ratio changed to 1:1, indicating a trans-cis isomerization during the photocycle of sR-II.

Immortalization of murine B cells in vitro with oncogene-containing retroviral vectors

A large panel of oncogene-containing retroviral vectors has been constructed and used to infect activated murine splenic B cells to determine whether particular oncogenes are capable of directly mediating B cell immortalization. Mature B cell lines have been consistently established with some of these retroviral vectors. These B cell lines arose at a low frequency, indicating that more genetic events were required in addition to infection with the retroviral vector for immortalization to occur. All such lines were LPS-dependent and non-tumorigenic. All lines secrete IgG and express surface IgG, but not IgD or IgM. In addition, they are CD11b+ and CD23-. These cells may be derived from the CD5 "lineage" or a related B cell subset and appear to be more susceptible to immortalization than conventional B cells.

Immortalization of murine B cells in vitro with oncogene-containing retroviral vectors

A large panel of oncogene-containing retroviral vectors has been constructed and used to infect activated murine splenic B cells to determine whether particular oncogenes are capable of directly mediating B cell immortalization. Mature B cell lines have been consistently established with some of these retroviral vectors. These B cell lines arose at a low frequency, indicating that more genetic events were required in addition to infection with the retroviral vector for immortalization to occur. All such lines were LPS-dependent and non-tumorigenic. All lines secrete IgG and express surface IgG, but not IgD or IgM. In addition, they are CD11b+ and CD23-. These cells may be derived from the CD5 "lineage" or a related B cell subset and appear to be more susceptible to immortalization than conventional B cells.

Phototaxis of Spiral Waves

The drift of spiral waves toward regions of higher light intensity was observed experimentally in the ruthenium-catalyzed Belousov-Zhabotinsky reaction. A light gradient can thus be used to manipulate optical information in new computational systems based on photochemical media. The drift of a gradient that is rotationally invariant in space is three to four times as fast as that of a translationally invariant gradient. Simulations based on the use of a cellular automaton, which is made isotropic by a semirandom distribution of cells, are in agreement with the experimental results.

Biochemical and photochemical properties of the photophobic receptors from Halobacterium halobium and Natronobacterium pharaonis

The phototaxis of Halobacterium halobium is initiated by two photoreceptors, the sensory rhodopsins sR-I and sR-II. An sR-II-like pigment has also been described in Natronobacterium pharaonis. In this work it was shown that N. pharaonis cells are repelled by light with a wavelength of 500 nm. A further comparison of membrane preparations from H. halobium (mutant D1) containing only sR-II and from N. pharaonis [strain SP1(28)] with a chromophoric protein (psR-II) resembling sR-II revealed substantial similarities. The biochemical and photochemical properties of the pigments are quite similar, with psR-II being more stable to external conditions such as pH and ionic strength of the buffer. Both pigments are bleached by low concentrations of hydroxylamine and can be reconstituted by the addition of all-trans-retinal. The absorption spectrum of psR-II is quite similar to sR-II including the shoulder on the short-wavelength side. After light excitation sR-II and psR-II undergo photocycles with at least three intermediates. The earliest intermediate has an absorption maximum above 520 nm and decays to a species which has a characteristic absorption (approximately 380 nm) of a deprotonated Schiff base. The final step is the regeneration of the original ground state via a red-shifted intermediate absorbing around 540 nm. From this cumulative evidence it can be concluded that, not only sR-II, but also the pigment from N. pharaonis is a photophobic photoreceptor.

[Toxicity of an organic Germanium compound: deleterious consequences of a "natural remedy"]

Reports mainly from Japan, recommend germanium (Ge)-containing compounds as "anti-cancer" and "immunostimulatory" remedies. We report on a 25-tear-old woman with stage II HIV disease who consumed a total of 47 g Ge as Ge-lactate-citrate 18%. She developed severe renal insufficiency (creatinine clearance 7 ml/min/1.73 m2, proteinuria 0.28 g/d) and hepatomegaly. Biopsies revealed tubulointerstitial nephropathy with vacuolar degeneration, mainly of distal tubular epithelia, and severe liver steatosis. Tissue Ge content in kidney and liver biopsy specimens was increased 68-and 140 fold respectively. In agreement with previous reports, renal dysfunction persisted 9 months later (creatinine clearance 11 ml/min/1.73 m2).

Tamm-Horsfall glycoprotein--inhibitor or promoter of calcium oxalate monohydrate crystallization processes?

The processes of calcium oxalate monohydrate (COM) crystal nucleation, growth and aggregation (agglomeration) generally have been studied using a wide variety of assay systems/conditions. This paper reviews the apparently conflicting data on the effects of Tamm-Horsfall glycoprotein (THP) on COM crystallization processes in vitro, with the main emphasis on crystal aggregation. According to its well-known physico-chemical properties, THP has a dual role in modifying crystal aggregation: at high pH and low ionic strength (IS). THP is a powerful crystal aggregation inhibitor. Upon lowering pH and raising IS, THP viscosity increases, leading to reduced crystal aggregation inhibition. In the presence of additional calcium ions, some THPs even become strong promoters of crystal aggregation. This phenomenon seems to be more pronounced in THPs isolated from recurrent calcium stone formers whose proteins exhibit an abnormally high tendency of polymerization. Recent studies suggest an inherited molecular abnormality of THP among some severe recurrent calcium stone formers.