Safety of paracentesis in inpatients.

INTRODUCTION: Prior research has suggested that paracentesis is free from complications such as acute renal failure (ARF) providing albumin is administered. Actual safety of paracentesis > 1,000 ml was assessed at a tertiary care hospital. METHODS: 300 inpatient paracenteses performed between 12/99 and 4/04 were identified by coding records, of which 40 procedures were excluded due to lack of pre- or post-procedure lab values. Charts were reviewed for serum creatinine (Scr) before and after procedures, ascites volume, and clinical outcomes. RESULTS: 44 deaths occurred after 260 paracenteses (16.9%). Among 33 patients with ARF, 13 (39.4%) died. Only 31/227 patients without ARF (13.7%) died (p < 0.001). Serum creatinine (Scr) > 1.6 mg/dl prior to paracentesis predicted a 22.5% rate of ARF, compared to 8% for Scr < 1.0 (p = 0.002). ARF increased as volume increased (9.9%, 12.4%, and 14.9%, for volumes of < 2,300, 2,300 - 3,200, and > 3,200 ml) but this trend did not have statistical significance (p = 0.426). ARF occurred in 11/69 (15.9%) of patients receiving albumin, compared to 22/191 (11.5%) of patients who did not (p = 0.462). CONCLUSIONS: Paracentesis in inpatients has significant rates of ARF and death. Scr > 1.6 prior to paracentesis predicts an increased rate of ARF. Development of ARF is associated with an increased rate of death. No advantage was demonstrated with administration of albumin. Pre- and post-paracentesis labwork should be routine in inpatients.

Inactivation of O6-methylguanine-DNA methyltransferase and sensitization of human tumor cells to killing by chloroethylnitrosourea by O6-methylguanine as a free base.

Human fibroblasts and tumor cells with constitutive levels of the DNA repair protein O6-methylguanine-DNA methyltransferase were incubated with mM concentrations of the free base O6-methylguanine for up to 24 h. This treatment depleted the cells of their transferase activity, and sensitized the cells to killing by the antineoplastic drug 1-[2-chloroethyl]-1-nitrosourea. Cells constitutively lacking the methyltransferase were not sensitized to cell killing. Cell free extracts incubated with O6-methylguanine also lost methyltransferase activity. Other alkylpurines, such as O6-methylguanosine, S6-methylthioguanine, O6-ethylguanine, and 3-methyladenine, did not have this effect on extracts of human tumor cells, while O6-methylguanosine and O6-methylguanine inactivated purified methyltransferase from Escherichia coli. The data suggest that the free base O6-methylguanine is probably a substrate for the methyltransferase. Calculation of the second order rate constants for free base versus O6-methylguanine in DNA, and experiments in which the free base was mixed with DNA containing O6-methylguanine before reaction with methyltransferase, indicated that the base in DNA is about 4 X 10(7) better as a substrate than is the free base. These results demonstrate that DNA repair capacity of tumor cells can be diminished without DNA damage, and suggest a method for increasing the efficiency of chemotherapy.

Multi-electrode neurostimulation system for treatment of cognitive impairments.

Peculiarities of neurostimulation organization by a multi-electrode system are considered. The system forms the spatially distributed field of current pulses that impact the nerve centers of the neck. An example is given for technical implementation of such a system in device SYMPATHOCOR and the method of its application: the dynamic correction of activity of the sympathetic nervous system. Results of its clinic application to treating the children with the attention deficit syndrome are given. It is shown that taking into account pathophysiological peculiarities of such a syndrome, it could be considered as a general model of cognitive impairments.

G protein-dependent activation of a phosphoinositide-specific phospholipase C in UMR-106 osteosarcoma cell membranes.

Recent evidence suggests that guanyl nucleotide binding (G) proteins are involved in receptor-mediated bone resorption and in osteoblastic function, but the nature of the G protein coupled to effectors that are involved in these skeletal effects is unknown. The purposes of this study were to determine (1) whether a G protein mediates activation of phosphoinositide-specific phospholipase C in UMR-106 rat osteosarcoma cells, and (2) whether parathyroid hormone (PTH) and a PTH-like protein (PLP) associated with humoral hypercalcemia of malignancy promote GTP-dependent PIP2 hydrolysis. Addition of GTP (10(-4) M) or guanosine 5'-0-(3-thiotriphosphate, GTP gamma S, 10(-5) M) to membranes prepared from UMR-106 cells labeled with [3H]myo-inositol increased both [3H]inositol trisphosphate (IP3) and [3H]inositol bisphosphate (IP2) formation. The increases in [3H]IP2 and [3H]IP3 produced by GTP were 8.6- and 4.3-fold, respectively. GTP gamma S produced a 17.6- and 11.9-fold increase in [3H]IP2 and [3H]IP3, respectively. The stimulatory effects of GTP and GTP gamma S were dose dependent (GTP ED50 = 3.9 x 10(-6) M; GTP gamma S ED50 = 2.5 x 10(-7) M) and progressive over 10 minutes and required the presence of Mg2+.GTP (10(-4) M) and GTP gamma S (10(-5) M) decreased membrane [3H]phosphoinositides concomitantly with increased [3H]IP2 and [3H]IP3. The GDP analog guanosine 5'-O-(2-thiodiphosphate, GDP beta S) alone did not alter [3H]IP2 or [3H]IP3 production but at 10(-4) M blocks the stimulatory effects of GTP and GTP gamma S. NaF (3 x 10(-2)M) produced a 2.8- and 2.0-fold stimulation of [3H]IP2 and [3H]IP3, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Thrombin stimulates inositol phosphate production and intracellular free calcium by a pertussis toxin-insensitive mechanism in osteosarcoma cells.

Human alpha-thrombin is known to elicit bone resorption in vitro and has been proposed as a mediator of increased bone turnover in inflammatory diseases. We used UMR 106-H5 rat osteoblast-like osteosarcoma cells to explore the signal transduction mechanism utilized by thrombin in bone. Thrombin produced a dose-dependent increase in the accumulation of [3H]inositol phosphates (IPs) in UMR 106-H5 cells prelabeled with [3H]myo-inositol (EC50 15 U/ml). In saponin-permeabilized cells, GTP gamma S increased [3H]IP production, whereas GDP beta S inhibited the response to both GTP gamma S and thrombin, indicating involvement of a G-protein in thrombin action. Thrombin produced a dose-dependent increase in intracellular free calcium (Cai2+) in UMR 106-H5 cells (EC50 1 U/ml; maximal increase 4-fold), as well as a small (20%) increase in [3H]thymidine incorporation. Treatment of UMR 106-H5 membranes with pertussis toxin (PT) and [32P]NAD+ resulted in labeling of a 40-kDa protein. However, pretreatment of cells with a dose of PT sufficient to produce maximal endogenous labeling of this protein failed to influence thrombin action on IP accumulation, Cai2+, or [3H]thymidine incorporation. In contrast, PT treatment of CCL39 hamster lung fibroblasts significantly blunted thrombin-stimulated [3H]IP accumulation and [3H]thymidine incorporation. These results suggest that thrombin raises Cai2+ in UMR 106-H5 cells by activating polyphosphoinositide-specific phospholipase C. Whereas in fibroblasts and platelets, thrombin receptors appear to couple to both PT-sensitive and PT-insensitive G-proteins, only a PT-insensitive G-protein appears to mediate thrombin action in UMR 106-H5 cells. Either these cells lack the relevant PT-sensitive G-protein or they possess thrombin receptors that selectively couple to a pertussis toxin-insensitive G-protein.

Thrombin and parathyroid hormone mobilize intracellular calcium in rat osteosarcoma cells by distinct pathways.

The mechanisms by which PTH and thrombin mobilize intracellular Ca2+ (Cai2+) were examined in UMR 106-H5 rat osteosarcoma cells. Bovine PTH-(1-34) (24 pM to 240 nM) produced a dose-dependent increase in Cai2+ (EC50, 3 nM), which returned to baseline within 75 sec. Human alpha-thrombin produced an increase in Cai2+ (ECmax, 10 U/ml) which was similar to that of PTH with respect to both magnitude and time course. Chelation of extracellular calcium with 5.0 mM EGTA did not alter the Cai2+ response to either PTH or thrombin. When added together at maximally effective concentrations, PTH and thrombin produced additive effects on Cai2+ in the presence and absence of EGTA. The additive effects of PTH and thrombin on Cai2+ were confirmed at the single cell level, using laser-based image analysis. Bradykinin (1 microM) produced a significant increase in Cai2+ in UMR 106-H5 cells which was of lesser magnitude than the peak 2- to 3-fold increase elicited by PTH or thrombin. Preexposure of cells to 10 U/ml thrombin for 2 min abolished the Cai2+ response to bradykinin, whereas preexposure to 240 nM PTH had no effect on the Cai2+ response to bradykinin. Thrombin elicited a rapid increase in the accumulation of 3H-labeled inositol phosphates (IP2 and IP3) in UMR 106-H5 cells, with increases in [3H]1,4,5-IP3 detectable as early as 15 sec after the addition of thrombin. Bradykinin increased [3H]IP production to a lesser extent than thrombin, whereas PTH neither increased [3H]IP accumulation nor potentiated the [3H]IP response to thrombin. The results suggest that thrombin and bradykinin mobilize Cai2+ from a shared IP3-responsive calcium pool, whereas PTH may use signals in addition to 1,4,5-IP3 to mobilize calcium from a distinct cellular calcium pool. Alternatively, specific calcium compartmentalization exists, and there is differential coupling of these agonists to the 1,4,5-IP3/Cai2+ pathway.

Risk assessment of low-level chemical exposures from consumer products under the U.S. Consumer Product Safety Commission chronic hazard guidelines.

The U.S. Consumer Product Safety Commission (CPSC) is an independent regulatory agency that was created in 1973. The CPSC has jurisdiction over more the 15,000 types of consumer products used in and around the home or by children, except items such as food, drugs, cosmetics, medical devices, pesticides, certain radioactive materials, products that emit radiation (e.g., microwave ovens), and automobiles. The CPSC has investigated many low-level exposures from consumer products, including formaldehyde emissions from urea-formaldehyde foam insulation and pressed wood products, CO and NO2 emmissions from combustion appliances, and dioxin in paper products. Many chemical hazards are addressed under the Federal Hazardous Substances Act (FHSA), which applies to acute and chronic health effects resulting from high- or low-level exposures. In 1992 the Commission issued guidelines for assessing chronic hazards under the FHSA, including carcinogenicity, neurotoxicity, reproductive/developmental toxicity, exposure, bioavailability, risk assessment, and acceptable risk. The chronic hazard guidelines describe a series of default assumptions, which are used in the absence of evidence to the contrary. However, the guidelines are intended to be sufficiently flexible to incorporate the latest scientific information. The use of alternative procedures is permissible, on a case-by-case basis, provided that the procedures used are scientifically defensible and supported by appropriate data. The application of the chronic hazard guidelines in assessing the risks from low-level exposures is discussed.

Serum theophylline profile with once-daily theophylline (Uniphyl) following conversion from intravenous theophylline in adult asthmatic patients.

Although guidelines are available for conversion from intravenous (IV) theophylline to twice-daily, oral, controlled-release theophylline, the optimal method for conversion to Uniphyl, a chronotherapeutically formulated, once-daily theophylline preparation, has not been previously evaluated. The present study was designed to prospectively evaluate a method for converting patients from IV theophylline to Uniphyl, to formulate simple, practical dosage recommendations for use in clinical practice. Ten patients with acute exacerbation of asthma receiving IV theophylline for > or = 48 hours and with steady state serum theophylline concentrations (STCs) between 4.5 and 15.5 mg/L (25 and 86 mumol/L) were enrolled into the study. Patients with STCs > or = 4.5 and < 12 mg/L (> or = 25 and < 66 mumol/L) and those with STCs > or = 12 and < or = 15.5 mg/L (> or = 66 and < or = 86 mumol/L) received their first Uniphyl dose immediately following termination of IV theophylline (No Time Lapse [NTL] group) and after a 4-hour delay (Time Lapse [TL] group), respectively. The differences in the area under the curve values between Uniphyl dosing and IV theophylline were 11% in the NTL group (1214.6 +/- 247.9 mumol/h.L-1 vs 1370.4 +/- 148.1 mumol/h.L-1, 95% confidence interval, 74% to 103%; P = 0.068) and 10% in the TL group (1959.4 +/- 165.1 mumol/h.L-1 vs 1784.6 +/- 119.4 mumol/h.L-1, 95% confidence interval, 103% to 117%; P = 0.013).(ABSTRACT TRUNCATED AT 250 WORDS)

E-cadherins identified in osteoblastic cells: effects of parathyroid hormone and extracellular calcium on localization.

The presence and regulation of cadherin localization in osteoblastic cells were examined. Monoclonal antibody (ECCD-1) that interferes with E-cadherin function prevented cell adhesion in UMR 106-H5 rat osteosarcoma cells and non-tumorigenic mouse calvarial MC3T3-E1 cells, whereas CCL39 fibroblast adhesion was not affected. Immunofluorescent antibodies (ECCD-2 and polyclonal L-CAMP P1) revealed cadherins are localized along the osteoblastic cell-cell boundaries. Exposure of UMR 106-H5 cells to bovine parathyroid hormone (1-84) (PTH; 10 ng/ml x 1 hr) or low calcium medium (1.0-0.025 mM) produced cellular retraction accompanied by intense immunofluorescence for cadherins throughout cells with a corresponding loss of punctate localization at remaining cell-cell adhesion points. Western immunoblot analysis indicated 108 kd and 115 kd cadherins are present, with a smaller 29.5 kd band that became predominantly associated with the cytosolic fraction of cells treated with parathyroid hormone or lowered calcium. The results demonstrate E-like cadherins are present in osteoblastic cells and implicate a regulatory role for parathyroid hormone and calcium in cadherin function and localization.

The facilitative actions of Bay K 8644 on norepinephrine and KCl-induced contractures of rabbit aortic rings.

The effect of the calcium channel agonist BAY K 8644 on the ability of KCl and norepinephrine to induce contractions of rabbit aortic rings has been examined in Krebs-Henseleit buffer containing either 4.0 or 6.8 mM potassium. BAY K 8644 (10(-8) to 10(-6) M) alone induced slowly developing aortic contractures which were 10 (at 4.0 mM potassium) or 20 (at 6.8 mM potassium) percent of the maximum obtainable with norepinephrine. These contractions were not observed in every experiment, but were more likely to occur at 6.8 mM (71% at 10(-6) M BAY K 8644) when compared to 4.0 mM (31% at 10(-6) M BAY K 8644) potassium buffer. BAY K 8644, in either potassium buffer, induced a statistically significant shift to the left in the norepinephrine dose-response curve. The norepinephrine dose-response curve was significantly curvilinear in the presence of 3 X 10(-8) M BAY K 8644 (6.8 mM potassium) and 10(-6) M BAY K 8644 (4.0 mM potassium). Similarly, BAY K 8644 induced sinistral shifts in the KCl dose-response curve with a curvilinear function observed at 3 X 10(-7) M BAY K 8644. These data show that BAY K 8644 is capable of inducing aortic contractures at potassium concentrations significantly lower than previously reported. Furthermore, BAY K 8644 facilitates opening of calcium channels by either potassium or norepinephrine. In contrast to others, our data indicates that BAY K 8644 can affect calcium channels activated by norepinephrine. Finally, our data suggest that the alpha and dihydropyridine receptors are capable of interacting and that occupation of one receptor can affect the action of a compound binding to the other receptor.

Heterogeneity of alpha 1 receptors associated with vascular smooth muscle: evidence from functional and ligand binding studies.

The nature of the alpha 1 receptor associated with rabbit aorta has been examined in functional and receptor binding studies. In isolated aortic rings the dose-response curve for (-)metaraminol was not parallel to that of (-)epinephrine, (-)norepinephrine or (-)phenylephrine. Following inactivation of a portion of the alpha receptors with phenoxybenzamine, the occupancy versus response relationship for metaraminol, in contrast to the other test agonists, was biphasic. These results suggest the possibility that metaraminol interacts with different functional groups on the alpha 1 receptor than the other test agonists. In microsomes prepared from frozen aorta, metaraminol bound to two classes of sites (KH = 0.41 +/- 0.12 microM, KL = 39.1 +/- 7.1 microM) labelled by the selective alpha 1 antagonist [3H] prazosin. Similar binding characteristics were observed in microsomes prepared from aorta shipped in serum on ice or aorta from animals killed in our laboratory. Norepinephrine also bound to two sites on the alpha receptor in all three preparations tested (KH = 0.06 +/- 0.01 microM, KL = 5.09 +/- 2.4 microM; estimates from frozen aorta). The Scatchard plot of [3H]prazosin binding to microsomes prepared from frozen aorta was curvilinear. Estimates of the affinities and site densities were 49.6 +/- 15.3 pM and 44.8 +/- 11.8 pmol/gm protein and 1.0 +/- 0.2 and 43.8 +/- 17.4 pmol/gm for the high and low affinity sites, respectively. These data are consistent with the idea that there are subtypes of the alpha 1 receptor.

Exogenous O6-methylguanine inhibits adduct removal and sensitizes human cells to killing by the chemical carcinogen N-methyl-N'-nitro-N-nitrosoguanidine.

We partially depleted the O6-methylguanine-DNA methyltransferase activity in four O6-methylguanine (O6-mGua) repair-proficient (Mer+) human cell strains with exogenous O6-mGua (2 mM for 3 h, a non-toxic regimen) and then challenged them with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). MT-partially depleted HT29 cells removed O6-mGua from DNA at about half the rate of control cells, while removal of 3-methyladenine was unaffected. In spite of partial depletion of MT, however, cell killing by MNNG in a colony-forming assay with HT29, A549, A498 or KD cells was not greatly affected. (This is in contrast to the dramatic potentiation of CNU cytotoxicity observed previously.) In an attempt to sensitize Mer+ strains to killing by MNNG, we treated cells with O6-mGua following MNNG exposure (0.4 mM for 4 days), in addition to the pre-MNNG treatment of 2 mM O6-mGua for 3 h. This sensitized KD and HT29 cells 2-fold to killing by MNNG, based on the dose at 10% survival, but did not sensitive Mer- A1336. However, post-treatment alone was as effective as combined pre- and post-treatment in sensitizing KD cells to killing. Thus, when the O6-mGua post-treatment was begun, greater than 50% of O6-mGua was already removed from cell DNA. Our findings may be accounted for by at least two schemes, one in which nonlethal O6-mGua are removed from DNA rapidly, while potentially lethal O6-mGua are repaired later. The other scheme proposes that exogenous O6-mGua increases the lethality of a non-O6-mGua lesion by reducing its repair both in Mer+ and Mer- cells. Both schemes are consistent with the hypothesis that O6-mGua may be a lethal DNA lesion in human cells.

Further evidence that ultraviolet radiation-enhanced reactivation of simian virus 40 in monkey kidney cells is not accompanied by mutagenesis.

Can simian virus 40 (SV40) be used to detect mutagenic DNA repair in cultured mammalian cells? The published evidence from different laboratories are in direct conflict. In order to decide between the conflicting evidence, we conducted experiments in two separate laboratories using experimental protocols similar to those previously used to investigate mutagenic repair with viral probes. Mutagenesis in SV40 virus stocks obtained by infecting ultraviolet (UV)-irradiated or unirradiated CV-1 monkey kidney cells with UV-irradiated or unirradiated temperature-sensitive SV40 mutant tsB201 was investigated. The frequency of reversion of the ts mutant to phenotypically wild-type virus was determined by assaying the virus stocks at permissive (33 degrees) and non-permissive (39 degrees) temperatures. These data show that (a) the reversion frequency for unirradiated virus propagated in irradiated cells was more than that in unirradiated cells; (b) irradiated virus gave more reversion than unirradiated virus in unirradiated and irradiated cells; and (c) irradiated virus had a lower reversion frequency in irradiated cells than in unirradiated cells. Reactivation experiments carried out in parallel; with the mutagenesis showed enhanced reactivation in UV-irradiated SV40 in UV-irradiated CV-1 cells. We conclude that enhanced reactivation of UV-irradiated SV40 was not mutagenic in monkey kidney cells.

Conversion from intravenous procainamide to oral sustained release tablets in cardiac patients.

There is as yet no established method for converting from intravenous to oral sustained release procainamide (Procan SR; Parke-Davis Canada Inc). The pharmacokinetics of simultaneous discontinuation of intravenous procainamide and administration of oral sustained release procainamide was studied in six patients with ventricular tachyarrhythmias. Patients were converted after ensuring that steady-state concentrations were achieved with intravenous procainamide. Serum procainamide levels were obtained at the time of conversion and 0.5, 1.0, 1.5, 2.0, 3.0, 4.0 and 6.0 h after conversion. The mean steady-state concentration (23.7 +/- 8.9 mumols/L) and the adjusted mean serum procainamide concentration with Procan SR (25.3 +/- 7.9 mumols/L) were not significantly different. This indicated that the serum procainamide concentration obtained with the intravenous infusion was not compromised when the patients were switched to oral therapy. Although mean percentage serum procainamide concentration fluctuation was 102.6 +/- 92.5, all patients tolerated the conversion well. Therefore, the method used in this study is an acceptable method of conversion.

[The optimization of combined physiotherapy in the system of rehabilitating victims with complicated fractures of the extremities]. / Optimizatsiia kompleksnoi fizioterapii v sisteme reabilitatsii postradavshikh s oslozhnennymi perelomami konechnostei.

The schemes were worked out for optimization of complex physiotherapy in rehabilitation system of patients with complicated fractures of extremities. This work was carried out on the basis of 178 dynamic clinic observations with application of biomechanical and roentgenological methods, as well as methods of mathematical modelling and prognostication. That made it possible to increase the efficiency of rehabilitation programs by 3.2--4.1 times. The article deals with the perspective trends in the development of this problem.

[The use of electromyostimulation for preventing and treating hypodynamic disorders in gunshot injuries to the extremities]. / Primenenie élektromiostimuliatsii dlia profilaktiki i lecheniia gipodinamicheskikh rasstroistv pri ognestrel'nykh povrezhdeniiakh konechnostei.

It was found out during the study of multichannel electromyostimulation (EMS) influence upon human organism and the adequacy of its physical load to adoptive and compensative possibilities of cardiovascular system that that method was effective for prophylaxis of disorders and rehabilitation of nervous and muscular system, and locomotor apparatus after a short period of hypodynamia. The EMS increases the working capacity of nervous and muscular apparatus, mass of muscles and their contraction strength due to improvement of nervous and muscular conductivity and blood supply of the extremity. The efficiency of EMS decreases considerably when degenerative changes are taking place.