Crystalluria in marathon runners

Summary In order to investigate further the possible relationship between urinary stone formation and marathon running, the crystalluria in seven male, stone forming runners was characterized. Particle size distribution curves (Coulter counter) and crystal number, size and morphology (scanning electron microscopy) were measured. These studies suggest that urinary stone formation may be accelerated in those subjects with previous histories of renal stone formation but that the nature of the crystalluria is favourably affected by an increase in fluid intake. The presence of large quantities of mucoid material in the urine of natural stone formers and its absence in the urine of stone-forming runners is cited as evidence for the existence of different aetiological mechanisms in these groups. It is concluded that while natural stone formers may be at chronic risk of stone formation due to pathological factors, marathon runners may be at acute risk due to factors associated with long distance running itself.     

Large fibres in urinary calculi — Promoters of stone formation

Summary Large fibres (ø 10–20 m, length up to 5,000 m) are sometimes imbedded in urinary calculi. It may be that these fibres can catch sediment particles and promote stone growth. By scanning electron microscopy the morphology of the fibres was studied as well as the relationship of the fibres with crystalline stone components. The reported findings suggest that the fibres are possibly formed in the tubuli as the result of an hitherto unknown defect.     

Demonstration of calmodulin-sensitive calcium translocation by isolated osteoclast plasma membrane vesicles

Summary Plasma membrane vesicles were prepared from chicken osteoclasts, and active calcium transport was demonstrated in a spectrofluorimetric assay using the fluorescent calcium concentration indicator, fura-2. Transport activity was inhibited by quercetin (10 M), sodium vanadate (10 M), and the anticalmodulin agents, compound 48/80 (20 and 200 g/ml) and calmidazolium (10 and 20 M). The transport rate (V_max, 1.3 nmol/mg protein/min) was not altered in the presence of the protonophore, nigericin (1 M), indicating that proton transport was not driving calcium transport. Release of accumulated calcium in the vesicles occurred with the addition of bromo-A23187 (5 M) or ionomycin (5 M). Increasing calcium transport occurred with increasing calcium concentration. Finally, the calmodulin content of the vesicles was demonstrated to be 54–134 U/mg protein. These results demonstrate that a calmodulin-sensitive, ATP-dependent calcium transporter is present in the osteoclast plasma membrane.     

Scanning electron microscopy-electron probe microanalysis study of the interface between apatite and wollastonite-containing glass-ceramic and rabbit tibia under load-bearing conditions after long-term implantation

Glass-ceramic implants containing oxy- and fluoroapatite [Ca₁₀(PO₄)₆(O, F₂)] and -wollastonite (CaSiO₃) were studied under load-bearing conditions in a segmental replacement model in the tibia of the rabbit. A 16-mm segment of the middle of the tibial shaft was resected at a point distal to the junction of the tibia and the fibula. The defect was replaced by a 15 mm-long hollow, cylindrical implant that was fixed by intramedullary nailing using Kirschner wire. The implants were 9 mm in diameter and 15 mm long bearing a central hole 3.05 mm in diameter. The rabbits used were killed 6 months, 1 year, 18 months, and 2 years after implantation. The interface between the bone and the glass-ceramic was investigated by scanning electron microscopy-electron-probe microanalysis (SEM-EPMA).None of the glass-ceramic implants broke, and the glass-ceramic had bonded directly to the bone tissue without any intervening soft tissue. A calcium-phosphorus layer (Ca-P layer) was observed at the glass-ceramic/bone interface. This layer was 30–100 m thick at 6 months after implantation, 60–110 m thick at 1 year after implantation, 80–200 m thick at 18 months, and 120–350 m thick at 2 years. At the lateral surface of the glass-ceramic uncovered by the bone, the calcium-phosphorus layer was 50–80 m thick at 6 months after implantation, 250–450 m thick at 1 year, 300 400 m thick at 18 months, and 300 m thick at 2 years. The thickness of the calcium-phosphorus layer increased moderately after long-term implantation. However, it was difficult to estimate the rate of increase in the thickness of calciumphosphorus layer.     

Percutaneous mid infra-red laser coronary angioplasty

Thirty patients with stenosis or total occlusion of the coronary artery were treated with mid infra-red pulsed laser angioplasty. The device consisted of a holmium-YAG laser operating at 2.1m, 500 mJ pulse^–1, 3.5 Hz, 250s pulse^–1. The laser was coupled into a multifibre catheter consisting of 37 optical fibres of 150m each concentrically arranged around a central lumen for the passage of a guidewire. This over-the-wire system allowed for safe and effective recanalization without perforation, death, arrythmia, distal embolus. Chest sensation but not pain occurred during laser emission. There was spasm in six patients which could be relieved by nitrates. In previously failed balloon angioplasty laser angioplasty allowed for successful repeat dilatation with low inflation pressure. Technical improvement should be made in reducing the dead space left in between the fibres at the distal catheter tip, in distal tip flexibility and in increasing the channel diameter for more laser stand-alone therapy.     

Comparison of mineral quality and quantity in iliac crest biopsies from high- and low-turnover osteoporosis: an FT-IR microspectroscopic investigation

Fourier-transform infrared microspectroscopy (FTIRM) allows analysis of mineral content, mineral crystal maturity and mineral composition at ~10- spatial resolution. Previous FTIRM analyses comparing 4- thick sections from non-decalcified iliac crest biopsies from women with post-menopausal osteoporosis, as contrasted with iliac crest tissue from individuals without evidence of metabolic bone disease, demonstrated significant differences in average mineral content (decreased in osteoporosis) and mineral crystal size/perfection (increased in osteoporosis). More importantly, these parameters, which vary throughout the tissue in relation to the tissue age in healthy bone, showed no such variation in bone biopsies from patients with osteoporosis. The present study compares the spatial and temporal variation in mineral quantity and properties in trabecular bone in high- and low-turnover osteoporosis. Specifically, six biopsies from women (n=5) and one man with high-turnover osteoporosis (age range 39–77) and four women and two men with low turnover osteoporosis (age range 37–63) were compared to ten normal biopsies from three men and seven woman (age range: 27–69). High turnover was defined as the presence of increased resorptive surface, higher than normal numbers of osteoclasts and greater than or equal to normal osteoblastic activity. Low turnover was defined as lower than normal resorptive surface, decreased osteoclast number and less than normal osteoblastic activity. Comparing variations in FTIR-derived values for each of the parameters measured at the surfaces of the trabecular bone to the maximum value observed in multiple trabeculae from each person, the high-turnover samples showed little change in the mineral: matrix ratio, carbonate: amide I ratio, crystallinity and acid phosphate content. The low-turnover samples also showed little change in these parameters, but in contrast to the high-turnover samples, the low-turnover samples showed a slight increase in these parameters, indicative of retarded, but existent resorption and formation. These data indicate that FTIR microspectroscopy can provide quantitative information on mineral changes in osteoporosis that are consistent with proposed mechanisms of bone loss.     

Effect of second messenger systems on oxalate uptake in renal epithelial cells

The oxalate transport system along with protein phosphorylation appears to be deranged in stone formers. This study was undertaken to characterize in LLC-PK₁ cells in culture the effect of altering specific intracellular second messenger systems on oxalate uptake. Cellular uptake experiments were performed at 37°C in buffer [265 mM mannitol, 5 mM NaOH, 5 mM KOH, 10 mM Ca-EGTA, 25 mM HEPES/TRIS, pH=7.4 or in Hank's balanced salt solution (HBSS)] containing 200 M labeled oxalate (1-¹⁴C, 0.3 Ci). Cells were preincubated with DAG (final concentration of 100 M), phorbol myristate acetate (10 M), forskolin (50 M), 8-bromo-cyclic AMP (50 M), trifluoroperazine (20 M) and low molecular weight heparin (1 mg/ml) for 10 min in the presence and absence of the anion transport inhibitor DIDS (100 M) and the effect(s) on oxalate uptake at 10, 25 and 45 min incubation were determined. Chemicals (DAG, forskolin, TPA and 8-bromo-cAMP) which stimulate protein kinase A or C activity resulted in an increased uptake of oxalate while inhibitors of these systems (trifluoroperazine and low molecular weight heparin) resulted in decreased oxalate uptake. The results dernonstrate that oxalate uptake in renal tubular cells is modulated by protein kinase C and A dependent mechanisms.     

Effects of urinary macromolecules on the crystallization of calcium oxalate

Summary The macromolecular fraction of urine with a molecular weight above 3,000 was isolated by dialysis. In the dialysed urine the rate of calcium oxalate (CaOx) crystallization was reduced both in the presence and absence of CaOx seed crystals. There was a clear relationship between crystallization and the relative concentration of the dialysed urine, with the highest crystallization propensity at the lowest concentration of macromolecules. Dilution of dialysed urine also affected crystal size distribution, with a predominance of small (2.8–4.5 m) crystals in 100% dialysed urine and of large (5.6–14.0 m) crystals in 5% dialysed urine. This is consistent with a macromolecular inhibition of both crystal growth and aggregation. Analysis of the crystal size distribution 120 min after supersaturation of whole urine to a level at which approximately 100 crystals in the size interval 3.5–5 m were detected in a Coulter counter surprisingly disclosed a higher mean crystal volume in urine samples from normal subjects than from stone formers. This gives support to the assumptions that macromolecules might be of importance during the initial phase of CaOx crystallization and that urine from stone formers and normal subjects might be different in this respect.     

Tetracycline double-labeling of iliac trabecular bone in 41 normal adults

Summary A histomorphometric evaluation of the iliac crest trabecular bone remodeling was performed after tetracycline double-labeling in 41 normal Danes (12 males and 29 females) aged 19 to 56 years. The fraction of formative (osteoid covered) and resorptive surfaces was unrelated to age but higher in males than in females (P<0.02 andP<0.05, respectively). The appositional rate (0.65±0.12 m/day) was unrelated to age and sex, whereas the fractional labeled surfaces were higher (P<0.01) in the males (0.18±0.08 m²/m²) than in the females (0.12±0.05 m²/m²), and among the females inversely related to age (R=–0.38,P<0.05). The bone formation rate at BMU level (0.50±0.20 m³/m²/day) was unrelated to sex, but among the females inversely related to age R=–0.49,P<0.01). The bone formation rate at tissue level was higher (P<0.02) in the males (0.13±0.07 m³/m²/day) than in the females (0.07±0.03 m³/m²/day) and among the females inversely correlated to age (R=–0.43,P<0.05). The age- and sex-dependent variations in the dynamic parameters underline the importance of a more elaborated normal material.     

252. Vergleichende Untersuchungen von Dopamin und Dobutamin bei chirurgischen Intensivpatienten

Zusammenfassung Intraindividuell wurde an 10 Patienten nach Ersatz der infrarenalen Bauchaorta Dopamin I mit 3g · kg^–1 · min^–1 und Dopamin II 6 g · kg^–1 min^–1 mit Dobutamin I 4 g · kg^–1 · min^–1 und Dobutamin II 8 g · kg^–1 · min^–1 auf ihre unterschiedliche Beeinflußung der cardialen und renalen Parameter untersucht. Signifikante haemodynamische Unterschiede ergaben sich in der Senkung des rechten Vorhofdrucks und linksventriculären Füllungsdrucks unter Dobutamin II im Vergleich zu einer Steigerung bei Dopamin II. Die Urin- und Natriumausscheidung war in beiden Gruppen bei Dopamin signifikant höher. Beim chirurgischen Intensivpatient ohne kardiale Vorerkrankung genügt zur Kreislaufsteigerung Dopamin.     

1.32 μm Nd:YAG laser during neurosurgical procedures experience with about 70 patients operated on with the MC 2100 unit

Summary The authors present their clinical experience with 1.32 m NdYAG Laser. After a series of experimental studies which demonstrated the adaptability of such a wavelength to central nervous surgery, they used such a Laser during current neurosurgical procedures. The MC 2100 unit combines two wavelengths 1.32 m and 1.06 m, and two emission modes: continuous wave (c.w.) and pulsed. This Laser has been used during 70 procedures: 54 supra-tentorial, 8 infra-tentorial, 5 intra-spinal, 3 intra-orbital. 600 m and 400 m fibers were preferred in most cases, either with a telescopic light handpiece or-less often—with a focussing handpiece. The quality of vaporization—close to that of CO₂ Laser—and of haemostasis —close to that of 1.06 m Nd-YAG Laser—makes this 1.32 m wavelength very suitable for neurosurgery. The manoeuverability due to the optic fibers is most interesting. Furthermore, such a Laser should have in the near future large applications in stereotactic and/ or endoscopic neurosurgery.     

Marathon running accompanied by transient decreases in urinary calcium and serum osteocalcin levels

Summary We evaluated the effects of marathon running on bone metabolism in 23 noncompetitive athletes (15 women, 8 men, age range 23–55 years). The volunteers were studied 10 days before, immediately after, and 1, 3, and 5 days after the run. Serum osteocalcin levels were decreased on average by 20% (from 4.9 to 3.9 g/liter, P=0.005) in men and by 10% (from 4.9 to 4.4 g/liter, P<0.05) in women at the end of the marathon, with lowest osteocalcin levels (67–55% of the prerun levels) encountered 1 day after the marathon. The activity of bone alkaline phosphatase was decreased in women (from 66.3 to 62.3 U/liter, P<0.05) after the run, and this drop was detectable at each checkup after the run. Urinary excretion of calcium was lowered on average by 82% in men (from 2.8 to 0.5 mol/minute, P<0.05) and by 76% in women (from 2.5 to 0.6 mol/minute, P<0.005) after the run, but had already returned to prerun levels 1 day after the marathon. Urinary excretion of hydroxyproline tended to rise in both men and women, but the change did not reach statistical significance in either sex. These changes suggest a transient suppression in osteoblast function during the marathon.Children's Hospital     

Diffusion theory of isotropic light dosimetry probe response

For the measurements of light energy fluence rate in tissues in vitro and in vivo we have developed an isotropic probe. The response of such a probe depends on the refractive index (n) of the medium. This has been measured in a collimated light beam with the probe in air, water (n=1.33), ehtylene glycol (n=1.43) and glycerin (n=1.46). The response as a function of n has also been calculated using diffusion theory, taking into account reflection at the boundaries. Simple formulas are proposed which very well approximate Fresnel reflection of unpolarized light, facilitating mathematical calculations. For a probe of 3.2 mm diameter with little light absorption the theoretical result depends only on n and differs from the experimental data by not more than 6 %. For a probe of 0.8 mm diameter with some light absorption excellent agreement between theory and experiment could be obtained by adjusting the (unknown) absorption and scattering coefficients ( _a, _s) of the probe material. However, a good fit was only possible within certain limits for _a, i.e. 0.35 mm^–1< _a<0.40 mm^–1, whereas _s (1-g) could be varied between at least 5 and 20 mm^–1 (g is the asymmetry parameter of the scattering function).     

Renal tubular differentiation in mouse and mouse metanephric culture

Sodium-potassium adenosine triphosphatase (Na-K-ATPase) activity was measured by microassay, and the surface density of basolateral membranes was measured morphometrically in postglomerular segments of single tubules isolated from normally developing, intact mouse kidneys and from transfilter metanephric cultures. Proximal tubule Na-K-ATPase activity was 1092±480 pmol/mm per hour in newborn mice, increasing to 2462±258 in 1-week-old and 3470–578 pmol/mm per hour in adult mice. The Na-K-ATPase activity in newborn mice was approximately one-third of the activity in adult mice. Tubular Na-K-ATPase in transfilter metanephric culture was 972±536 pmol/mm per hour, a mean value almost identical to that in newborn mice. The surface density of basolateral cell membranes was 1.36±0.60 m²/m³ in newborn mice and 1.34±0.45 m²/m³ in 1-week-old mice, increasing to 2.70±0.98 m²/m³ in 4-week-old mice and 2.89±0.51 m²/m³ in adult mice. The surface density of tubular basolateral cell membranes in transfilter metanephric culture was 1.13±0.51 m²/m³, not significantly different from the surface density in newborn mice. The calculated mean surface area of basolateral membranes per unit tubular length was greater in cultures than in newborns, however, because total epithelial volume per unit length was significantly larger in the cultured tubules. Membrane surface area in intact mice increased with age, the surface area per unit length of tubule in adults being 4.6 times the area in newborn animals. The ratio of enzyme activity to membrane surface area more than doubled in the 1st week of life without any increase in the density or surface area of basolateral membranes. The ratio fell thereafter, as membrane area increased with maturation, to a value in the adult animal three-fourths of that in the newborn. The early postnatal increase in enzyme activity, beginning almost immediately after birth, possibly relates to an increased density of enzyme sites on the membrane. The postnatal spurt in enzyme activity, without a corresponding increase in membrane area, suggests that tubules have considerable functional reserve in generating a complement of sodium pumps. The studies of proximal tubules grown in metanephric culture show that the basolateral membranes and the sodium pump are initiated independently of renal blood flow and tubular fluid flow, presumably as inherent characteristics. The functional data confirm the similarity, already shown by morphometric studies, between natural tubules and those grown in culture.     

27. Nachkontrolle und Rezidivprophylaxe nach Strumaresektion

Zusammenfassung Da die Strumaresektion nur eine symptomatische Maßnahme ist, kommt es bei etwa 15 %. zu einem Rezidiv. Der erhöhte TSH-Spiegel (Jod- oder Hormonmangel) muß daher lebenslang durch Substitution gesenkt werden: a) euthyreote Strumen: beginnend pop. 2 × wöchentl. 100 g T4 oder 100 g T4 mit 20 g T3. b) hyperthyreote Strumen: nach 2 – 3 Monaten Vorgehen wie a). c) Nach Op. tox. Adenome beginnend 14 Tage pop. wie a). Im eigenen Krankengut beträgt durch die systematische Rezidivprophylaxe die Rezidivquote 1,7 %. Die Organisation der Rezidivprophylaxe mit sogenannten Strumakarten wird demonstriert.     

Measurement of the risk of calcium phosphate crystallization in urine

Summary A method is described for analysis of the risk of calcium phosphate (CaP) crystallization in urine samples. The pH required for formation of 500 crystals in the size range 3.5 to 5 m (pH_CaP) was determined in a Coulter Counter following addition of sodium hydroxide. The risk of CaP crystallization (CaP-CR) was defined as: 1/(pH_CaP–5.8). CaP-CR was determined in 24 h urine collections from 25 patients with calcium stone disease and 26 normal subjects, each urine diluted to a creatinine concentration of 5 mol per ml. The mean (±SD) CaP-CR was 0.71±0.18 and 0.63±0.14 respectively and did not differ significantly. This method might be useful for evaluations and follow-up of stone formers with respect to the risk of CaP precipitation and stone formation.     

Secretory territories and rate of matrix production of osteoblasts

The secretory territories of rat osteoblasts on the parietal bone were measured directly using scanning electron microscopy. The mean territory of 4620 cells in 19 fields was 154 m² per osteoblast. The range for the fields was 136 to 177 m² per osteoblast. Four hundred cells were measured individually—for these the mean value per osteoblast was 143 m² with a standard deviation of 33. The daily rate of apposition over an 8 day period was 3.12 m (standard deviation 0.22) measured by tetracycline marking of the mineral front. This gave a daily matrix production rate of approximately 470 m³ per osteoblast.

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Zusammenfassung Die Ausscheidungsbereiche von Ratten-Osteoblasten des Scheitelbeines wurden mit dem Raster-Elektronenmikroskop direkt gemessen. Der durchschnittliche Bereich von 4620 Zellen in 19 Gesichtsfeldern war 154 m² per osteoblast. Der Streubereich lag in den verschiedenen Gesichtsfeldern zwischen 136 und 177 m² per Osteoblast. 400 Zellen wurden einzeln gemessen. Bei diesen war der Durchschnittswert per Osteoblast 143 m², mit einer Standard-Abweichung von 33. Die tägliche Anlagerungsrate während einer Periode von 8 Tagen war 3,12 m (Standard-Abweichung 0,22); sie wurde mittels Tetracyclinmarkierung der Mineralisierungsfront gemessen. Dies ergab eine tägliche Produktionsrate der Matrix von etwa 470 m³ per Osteoblast.

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Résumé Les territoires sécrétoires des ostéoblastes d'os pariétal de rats sont déterminées en utilisant la microscopie électronique à balayage. Le territoire moyen de 4.620 cellules, dans 19 territoires, est de 154 m² par ostéoblaste. Les valeurs extrêmes par champ varient de 136 à 177 m² par ostéoblaste. Quatre cent cellules sont mesurées individuellement; la valeur moyenne par ostéoblaste est de 143 m³ avec une déviation standard de 33. Le taux d'apposition journalier, mesuré par la tétracycline pendant 8 jours, est de 3.12 m (déviation standard 0.22). Ce qui correspond à une production matricielle journalière d'environ 470 m³ par ostéoblaste.

     

Taxol inhibits osteoclastic bone resorption

Summary We have examined the effect of the anti-tumor compound taxol, on osteoclastic bone resorption. In the bone slice assay, taxol (0.1–0.001 M) dose-dependently inhibited bone resorption with an IC₅₀ of 0.08 M. Osteoclast survival on bone slices was unaffected by 0.01–1 M taxol, but 10 M was cytotoxic. Taxol (1 M) also ihibited osteoclast spreading (45%) on fibronectin-coated slides. The antiproliterative effects of taxol are due to its unique ability to stabilize microtubules. Primary osteoclasts are nonproliferating end cells, so taxol probably inhibits bone resorption by intertering with other microtubule-dependent functions such as cell polarization, motility or vesicle exocytosis. Since these inhibitory effects on osteoclasts in vitro are seen with therapeutically relevant concentrations, taxol therapy may have beneficial side-effects e.g. inhibition of hyperealcemia and bone metastases.     

Biochemical bone markers compared with bone density measurement by dual energy X-ray absorptiometry

In contrast to medical imaging, the biochemical markers allow a more frequent determination and are not as invasive as histomorphometric methods. We investigated biochemical markers of type I collagen compared with bone density measurements in 85 females between 41 and 89 years of age (median: 57 years). The bone density measurements were performed by dual-energy X-ray absorptiometry (DXA) on the lumbar spine (L_1–4). The bone density measurements were stated as percentage of the norm. All patients were divided into three groups: I=<80%; II=80–120%; III=>120%. Based on this classification the median concentration of the I-carboxyterminal propeptide of type I procollagen in serum (S-PICP) as an anabolic marker of type I collagen increased significantly with rising bone density: I 65.0^* g/liter (interquartile range: 52.1–78.0 g/liter); II 85.9^* g/liter (52.1–115.5 g/liter); III 81.4 g/liter (62.0–101.0 g/liter); ^* P<0.05. The concentration of urinary pyridinolines (U-PYR) as a marker for degradation of type I collagen decreased. The I-carboxyterminal telopeptide (S-ICTP) and osteocalcin (S-BGP) did not change. The multivariate regression analysis showed no relationship between bone density measurement and biochemical bone markers. Only the age significantly correlated negatively with bone density measurement. For a better assessment of type I collagen metabolism we created a b-quotient by dividing the sum of S-PICP and S-BGP by U-PYR. The median b-quotient increased significantly: I 1.55^*+ (0.97–2.04); II 2.09^* (1.57–2.86); III 2.46⁺ (1.58–3.22);^*+ P<0.05. Changes in bone metabolism cannot be identified by the determination of a single marker. However, the improved biochemical diagnostic measurement using the b-quotient may provide early information about the progression of a metabolic disorder within the interval of imaging.     

Sutureless anastomosis of blood vessels using cyanoacrylate adhesives

On the assumption that the remaining suture threads of the anastomotic line play an important role in the progression of anastomotic neointimal hyperplasia, we performed an experimental study on the sutureless anastomosis of blood vessels. An expanded polytetrafluoroethylene graft, 5 mm in diameter and 2 cm in length, was implanted on the abdominal aorta of mongrel adult using one of three methods of anastomosis, namely; a continuous suture, a stay suture, or sutureless anastomosis. Overall patency rates were 83.3 per cent, 91.7 per cent and 75.0 per cent respectively. The thickness of the pannus in the distal anastomotic line after 12 months was 107 m in one graft in the continuous suture group, 106 m and 222 m in 2 grafts each in the stay suture group, and 41 m and 117 m in 2 grafts each in the sutureless group. Because there were cases of patency even after 12 months with a very small pannus thickness, sutureless anastomosis is considered to be a useful method of preventing anastomotic neointimal hyperplasia.