Primary malignant melanoma of the bladder

Primary malignant melanomma of bladder is extremely rare: 18 cases are reported to date. An 82 year-old man underwent trans-urethral resection of bladder for a bleeding tumor of the posterior wall. Histological diagnosis was melanoma of the bladder. There was no history of previous or regressed cutaneous malignant melanoma. Margins of the bladder lesion contained atypical melanocytes similar to those commonly seen in the periphery of primary mucous membrane lesions. Clinical studies and radiological examinations were negative for other primary site of melanoma. The patient had a bladder recurrence that was consistent with primary tumor and died of widespread disease 9 months after diagnosis.     

Effect of divalent cations on structure-function relationships of the antitumor protein α-sarcin

α-Sarcin binds one Zn(II) cation per protein molecule, with a K_d value of 0.9 mM, determined by equilibrium dialysis experiments. Ca(II), Mg(II), and Mn(II) do not bind to α-sarcin. Cd(II) and Co(II) also behave as Zn(II). The binding produces local modifications on the protein conformation affecting the microenvironment of tryptophan residues. The three cations modify the fluorescence emission of the protein. The near-u. v. circular dichroism spectrum of the protein is also altered. The binding of Zn(II) and related cations does not modify the secondary structure of the protein. The ribonucleolytic activity of a-sarcin is inhibited upon Zn(II) binding, but no alteration of the ability of the protein to aggregate phospholipid vesicles has been observed.     

Risk Factors in the Use of Benzodiazepines

Gené-Badia J, Blay-Pueyo C and Soler-Vila M. Risk factorsin the use of benzodiazepines. Family Practice 1988; 5: 283–288. A case-control study was carried out on 107 benzodiazepine usersand 214 controls not treated with anxiolytic-hypnotic agents,chosen randomly and matched two to one for each case by age,sex and family doctor. The users presented a higher degree ofpsychic disorder than the controls, with depression, interpersonalsensitivity, and the total number of symptoms being the elementsdistinguishing the two groups. We have found two factors thatput the population at large at risk for using benzodiazepines;the family doctor's diagnosis of a mental disorder in the clinicalhistory and the daily use of drugs other than benzodiazepinesexplained the risk independently. The presence of chronic disorders,especially cardiological and musculoskeletal disorders, alsoshowed a significant risk, but were only explained by theirclose association with one of the first two factors. It is postulatedthat general practitioners, who are the principal prescribersof drugs, are causing over-medication in the population.     

Multicenter Pilot Study of a Serpentine Balloon-Expandable Stent (beStentTM): Acute Angiographic and Clinical Results

The beStent is a new stainless steel, balloon-expandable mesh stent which has a unique serpentine design. Rotation of the unique low stress junctions upon expansion leads to orthogonal locking of the wires, maximizing radial strength and assuring zero shortening. The stent has delineating gold markers which assure precise positioning. We aim to present the initial acute results in a pilot registry for stent evaluation. Two hundred eighty-four stents were used in a total of 217 patients (age 57.9 ± 3.10 years; 178 males; 39 females) in seven centers, for variable indications. Stents of 15-, 25-, and 35-mm length were used. The arteries treated were the left anterior descending (n = 112, 42%), circumflex (n = 54, 20.2%), right coronary (n = 95, 35.5%), left main (n = 1, 0.4%), and vein graft (n = 5, 1.9%). Lesion types were: A in 42 patients (16.5%); B1 in 53 patients (20.7%); B2 in 81 patients (31.8%); and C in 79 patients (31%). One hundred fifty-nine patients required one stent, 40 patients required two stents, and 18 patients required three or more stents. Anticoagulation protocol included procedural heparin with aspirin with/without ticlopidine. Smooth angiographie results were obtained in all cases with no plaque herniation. Acute angiographic success was obtained in 97% of the patients, and acute clinical success in 95% of the patients. Complications within 30 days were: 3 deaths (1.4%) (2 noncardiac); 2 (0.9%) myocardial infarctions; and 2 (0.9%) stent thromboses. Therefore, the beStent is useful in treatment of complex lesions of variable length and complexity, providing excellent acute results with a low complication rate, in spite of unfavorable basic clinical and angiographie characteristics.     

A New Acceleration Driven Pacemaker: Rate Modulation Versus Normal Sinus Rhythm—Comparison During Treadmill Exercise

The pocing rate response of a new acceleration driven pulse generator (SWING 100, SORIN BIOMEDICA) was compared with simultaneous normal sinus rhythm (NSR) during two different treadmill exercises. This pacemaker has a gravitational acceleration sensor able to discriminate between physical activities and vibrations. Six healthy volunteers (three male, three female; aged 21.7 ± 4,3 years), with the pacemaker strapped to their right infraclavicular area, performed each test three times with different rise response curve (RRC) each time: fast, normal, and slow. The fall response curve used was the same as the rising one during each test. Pacing rates were recorded using the VEGA analyzer (SORIN BIOMEDICA) and compared with simultaneous NSR recorded by a 7-channel ECG recorder (MINGOGRAF 7, SIEMENS), During all tests immediate (within seconds) rapid increase in pacemaker rate was seen up to about 60 seconds, then a slower increase followed thereafter. The mean correlation between pacing rates and NSR during the Bruce tests were 0.7941 ± 0.10, 0.8562 ± 0.14, and 0.8292 ± 0.07; during the discontinous tests 0.7292 ± 0.16, 0.7233 ± 0.10, and 0.7480 ± 0.11 for fast, normal, and slow RRC, respectively. Each 30 seconds, nonsignificant differences were present between pacing rate and NSR during all the discontinuous tests; similar responses were observed only during the first two stages of Bruce tests after which NSR was significantly higher than pacemaker rates. The speed of rise to upper rate was the main difference between the different programs (fast, normal, and slow). The discontinuous tests showed that the pacemaker responds more to speed than to grade. In conclusion, the Swing pacemaker is easy to use and program, fast, reliable, and is able to mimic the normal sinus behavior especially during discontinuous activities.     

ACETALDEHYDE METABOLISM: DIFFERENCES BETWEEN UChA AND UChB RATS

In order to explore the influence of acetaldehyde (AcH) metabolismon the voluntary ethanol intake of genetically low (UChA) andhigh (UChB) ethanol consumer rats, the AcH disappearance rate(ADR) after incubation with homogenates and subcellular fractionsfrom liver and brain was determined. In addition, the effectof disulfiram pretreatment on AcH metabolism was studied. Maleadult rats of both strains were used. ADR was assayed in totalhomogenates, and in mitochondrial as well as 9000 g supernatantfractions of liver and brain. AcH was measured by gas chromatography.In some experiments, rats were pretreated with disulfiram (300mg/kg po) 24 hr before the studies. The result showed no straindifference in ADR in homogenates or subcellular fractions ofliver from untreated rats, but for disulfiram pretreated ratsa significantly lower decrease of ADR in samples from UChB comparedto UChA rats was observed. This result is consistent with alower peak AcH level in UChB compared to UChA rats after a loadof ethanol (60 mmole/kg ip). Concerning brain homogenates, ahigher ADR was observed in homogenates and crude mitochondrialfractions of UChB than of UChA rats. This difference was notobserved when the incubation was performed without adding NADor in the absence of oxygen. These results provide evidenceof strain differences in mitochondrial AcH metabolism, the natureand origin of which deserve further study.     

ETHANOL DECREASES BASAL CYTOSOLIC-FREE CALCIUM CONCENTRATION IN CULTURED SKELETAL MUSCLE CELLS

We analysed the effect of ethanol on basal cytosolic-free calciumconcentration ([Ca²⁺]₁) in cultured rat myocytes. Ethanol causeda dose-dependent decrease of the resting [Ca²⁺]₁). Removal ofethanol was followed by a transitory increase of [Ca²⁺]₁ abovethe basal level. In cells chronically exposed to ethanol, [Ca²⁺]₁normalized to the previous level.