Urological emergencies

Every general practitioner has to deal with urologic emergencies. The most frequent illnesses are urinary retention, acute scrotum, priapism, macrohematuria, nephritic colic, obstructive pyelonephritis and pyonephrosis. Whereas urinary retention, as well as acute ureteric stone colic must generally be treated by the practitioner, the urologist must often be consulted in case of an acute scrotum or for priapism. Testicular torsion is one situation, where surgical treatment needs to be performed within 6 hours. Of utmost importance is his timely assistance with the obstructive pyelonephritis and pyonephrosis. These are initially often not recognized, especially because the first ultrasound examination of the intrarenal pyelone may not show a dilatation of the collecting system despite obstruction. If the adequate treatment with drainage and antibiotics is applied too late, this can result in serious and potentially lethal consequences.     

The effect of endothelin and its antagonist Bosentan on hemodynamics and microvascular exchange in cirrhotic rat liver

BACKGROUND/AIMS: To characterize the effects of endothelin-1 and of Bosentan, a mixed endothelin antagonist, on hepatic hemodynamics in cirrhotic animals in vivo and on hepatic microvascular exchange in the perfused rat liver. METHODS: Biliary cirrhosis was induced by bile duct ligation, and micronodular cirrhosis by chronic exposure to phenobarbital/CCl4 in male rats. Hepatic hemodynamics were studied under basal conditions and after administration of Bosentan (3-30 mg/kg) by the microsphere technique. Microvascular exchange was assessed in the in situ perfused rat liver by the multiple indicator dilution technique. RESULTS: Bosentan lowered portal pressure in a dose-dependent fashion; at the highest dose tested, this decrease averaged -29+/-11 and -26+/-8% in biliary and micronodular cirrhosis, respectively (p<0.01). This was achieved mainly via a marked decrease in hepatic arterial flow. In the perfused liver, endothelin-1 induced a dose-dependent vasoconstriction; up to 10(-9) mol/l; this was not associated with any effect on viability. At this dose, endothelin-1 markedly decreased extravascular albumin space in both controls and micronodular cirrhosis; this could be antagonized by Bosentan 10(-5) mol/l. CONCLUSIONS: Endothelin-1 affects hepatic microvascular exchange, presumably by a direct effect on hepatic sinusoidal endothelial cells. A mixed endothelin antagonist lowers portal pressure in vivo, presumably by acting on hepatic stellate cells, and counteracts the microvascular effects of endothelin-1 in vitro. These properties could prove useful in treatment of portal hypertension.     

High-output congestive heart failure following transjugular intrahepatic portal-systemic shunting

A hyperdynamic circulatory state with elevated cardiac output, decreased peripheral vascular resistance, and sodium retention occurs in patients with portal cirrhosis. Surgical portal-systemic shunts and transjugular intrahepatic portal-systemic shunts (TIPS) have been shown to worsen the high-output state in these patients. However, clinical evidence of high-output congestive heart failure has been reported only rarely to complicate cirrhosis. We describe a patient who developed high-output congestive heart failure with markedly elevated filling pressures after TIPS and had complete resolution of heart failure after liver transplantation.     

Factors determining the outcome of scaling and root planing

Scaling and root planing are the predominant and recognized forms of periodontal therapy. They have been known for centuries, and have been investigated with increasing intensity since the turn of the century. Scaling and root planing aim at therapeutic changes of the "hard tissue lesion" at the root surface, in order to render it biologically acceptable to cells capable of attaching to it. Two major components of these root surface alterations are calculus and cementum alterations. Numerous studies have shown that scaling and root planing effectively removes subgingival deposits, and that this removal is seldom complete in deeper pockets. Even though beneficial clinical effects of scaling and root planing have been shown, it is unlikely that the full potential of healing is utilized today due to technical shortcomings. Several studies have shown that the design and dimensions of curets as used today are not optimal. These instruments are for many situations too big, subject to rapid dulling, and produce a smear layer. Chemical agents have been used to remove this layer with limited success. The therapist is a virtually unknown factor in the system of delivering scaling and root planing. A recent study showed that scaling and root planing forces used by different therapists on similar root surfaces varied by factors greater than 10. In addition, higher forces were shown to remove significantly more root substance. Apparently there is a large subjective component included in the delivery of scaling and root planing therapy. Even though scaling and root planing have been shown to be effective therapeutic procedures, many aspects require more research.     

Mass transfer in aerated fermentation broths in a stirred tank reactor

The volumetric mass transfer coefficients, k_La, measured in a pilot plant (0.1 m³) and an industrial (67.5 m³) fermentor during an actual fermentation process are presented. Problems related to the estimation of the phsyical properties as well as to the correlation of experimental data and to scale up procedures are discussed. Although the scale up factor was rather high, both sets of data could be represented by single correlation. Comparison of the experimental data with several available correlations demonstrated the need for pilot plant experiments and scale up procedures, since it is almost impossible to take into account all relevant system properties.     

Single machine batch scheduling with release times and delivery costs

We study single machine batch scheduling with release times. Our goal is to minimize the sum of weighted flow times (or completion times) and delivery costs. Since the problem is strongly $\mathcal{NP}$ -hard even with no delivery cost and identical weights for all jobs, an approximation algorithm is presented for the problem with identical weights. This uses the polynomial time solution we give for the preemptive version of the problem. We also present an evolutionary metaheuristic algorithm for the general case. Computational results show very small gaps between the results of the metaheuristic and the lower bound.     

Determination of the scattering coefficient and the anisotropy factor from laser Doppler spectra of liquids including blood

Laser Doppler measurements were performed on scattering liquids flowing through a highly scattering static medium to determine the scattering coefficient and the anisotropy factor of the liquids. Monte Carlo simulations of light propagation in the static and moving media were used to calculate the Doppler spectra for suspensions of polystyrene spheres in water, and these spectra were in excellent agreement with experimental results. A faster Monte Carlo code was developed so that nonlinear regressions to the measured laser Doppler spectra could be used to determine the anisotropy factor of other liquids. This approach was used to deduce the scattering properties of Intralipid and blood at λ = 820 nm. It was found that the anisotropy factor of blood is well described by Mie theory in contradiction to results reported in the literature that were obtained by goniometric measurement of the phase function.     

Combined hyperlipidemia in transgenic mice overexpressing human apolipoprotein Cl

We have generated transgenic mice over-expressing human apolipoprotein CI (apo CI) using the native gene joined to the downstream 154-bp liver-specific enhancer that we defined for apo E. Human apo CI (HuCI)-transgenic mice showed elevation of plasma triglycerides (mg/dl) compared to controls in both the fasted (211 +/- 81 vs 123 +/- 52, P = 0.0001) and fed (265 +/- 105 vs 146 +/- 68, P < 0.0001) states. Unlike the human apo CII (HuCII)- and apo CIII (HuCIII)-transgenic mouse models of hypertriglyceridemia, plasma cholesterol was disproportionately elevated (95 +/- 23 vs 73 +/- 23, P = 0.002, fasted and 90 +/- 24 vs 61 +/- 14, P < 0.0001, fed). Lipoprotein fractionation showed increased VLDL and IDL + LDL with an increased cholesterol/triglyceride ratio (0.114 vs 0.065, P = 0.02, in VLDL). The VLDL apo E/apo B ratio was decreased 3.4-fold (P = 0.05) and apo CII and apo CIII decreased in proportion to apo E. Triglyceride and apo B production rates were normal, but clearance rates of VLDL triglycerides and postlipolysis lipoprotein "remnants" were significantly slowed. Plasma apo B was significantly elevated. Unlike HuCII- and HuCIII-transgenic mice, VLDL from HuCI transgenic mice bound heparin-Sepharose, a model for cell-surface glycosaminoglycans, normally. In summary, apo CI overexpression is associated with decreased particulate uptake of apo B-containing lipoproteins, leading to increased levels of several potentially atherogenic species, including cholesterol-enriched VLDL, IDL, and LDL.