Outcome of women is impaired in patients undergoing emergency coronary artery bypass grafting for failed PTCA

There is an ongoing debate whether female gender is associated with increased cardiovascular morbidity and mortality, especially after coronary interventions. The impact of gender on the outcome of patients undergoing emergency coronary artery bypass grafting (CABG) for failed PTCA was analyzed. Clinical and procedural data of all patients who underwent PTCA and subsequent emergency CABG at our institution from 1989 to 1998 were assessed. During these 10 years, 6681 PTCA procedures were performed, 1312 in women (19.6%). Subsequently, 110 patients underwent emergency CABG of whom 32 were females (29.1%). Postoperatively, 9 women and 5 men died (mortality 12.7%). Women presented with higher age (61.2 +/- 2.1 vs. 58.3 +/- 1.0 years, n.s.), smaller height (1.61 +/- 0.01 vs. 1.76 +/- 0.01 m, p < 0.0001), lower weight (67.7 +/- 2.4 vs. 82.1 +/- 1.2 kg, p < 0.0001), smaller body surface area (1.70 +/- 0.04 vs. 1.98 +/- 0.02 m2, p < 0.0001), and higher comorbidity as expressed by their Cleveland score (7.9 +/- 0.3 vs. 7.1 +/- 0.2, p = 0.013). The risk for failure of PTCA with subsequent emergency CABG was higher in women than in men (2.4% vs. 1.5%, p = 0.012, odds ratio 1.66) as well as for postoperative death (28.1% vs. 6.4%, p = 0.004, odds ratio 4.39). Women had longer in-hospital stays (19.7 +/- 4.2 vs. 12.9 +/- 1.3 days, p = 0.044). Logistic regression analyses found lower weight (p = 0.003), higher number of diseased coronary vessels (p = 0.024) and higher Cleveland score (p = 0.023) to be independent predictors of operative mortality. A Kaplan-Meier model (follow-up 5.3 +/- 2.5 years) showed an increased in-hospital mortality in women (p = 0.0034, log rang test), but a comparable long-term survival. Women had an increased risk for failure of PTCA and a markedly higher operative mortality after emergency CABG. In multivariate analyses, however, gender was not an independent predictor of postoperative death.

A [2]catenane and a [2]rotaxane as prototypes of topological and Euclidean molecular "rubber gloves"

A [2]catenane and a [2]rotaxane have been prepared from a C2-symmetric, 2,9-diphenyl-1,10-phenanthroline-based (dpp-based) macrocycle incorporating a 1,5-dioxynaphthalene subunit by means of the transition metal templated technique. In the case of the catenane, this macrocycle is interlocked with a dpp-based macrocycle that is oriented through the location of a p-tolyl substituent in the 4-position of the phenanthroline subunit. In the case of the rotaxane, the C2-symmetric macrocycle is threaded onto an oriented, dumbbell-shaped molecule, based on the same 4-p-tolyl-1,10-phenanthroline subunit, which bears tetraarylmethane stoppers. Both species are chemically achiral molecules, yet they are composed entirely of asymmetric, mirror-image conformations. Conformational enantiomerization processes therefore take place exclusively by chiral pathways, conferring on these molecules the "rubber glove" property. However, while the molecular graph (constitutional formula) of the [2]rotaxane can be deformed into a planar and, hence, rigidly achiral representation, a feature shared by a few other compounds in the literature that have been characterized as "Euclidean rubber gloves", the molecular graph of the [2]catenane cannot be deformed in this way. It therefore has the unique property of being a chemically achiral "topological rubber glove".

Comprehensive analysis of the genetic factors determining expression and function of hepatic CYP2D6

Variable expression and function of the cytochrome P4502D6 (CYP2D6) leads to distinct phenotypes termed ultrarapid (UM), extensive (EM), intermediate (IM) and poor metabolizer (PM). Whereas the PM phenotype is known to be caused by two null-alleles leading to absence of functional CYP2D6 protein, the large variability among individuals with functional alleles remained largely unexplained. In this study, we systematically investigated 76 liver biopsies from individuals with known sparteine metabolic ratios (MRS) for the relationships between CYP2D6 genotype, microsomal protein expression, bufuralol 1'-hydroxylase activity and in-vivo phenotype. Average CYP2D6 protein levels ranged from undetectable in PMs (MRS > 20) to 2.6 +/- 2.7 pmol/mg microsomal protein in IMs (1.2 < MRS< 20), 7.6 +/- 4.7 in EMs (0.2 < MRS < 1.2) and 23.8 +/- 7.7 in UMs (MRS < 0.2), respectively. Analysis with respect to genotype demonstrated gradually increased expression and function for individuals with no, one, two or three functional gene copies per genome. The recently discovered -1584 C/G promoter polymorphism was identified as another major factor for expression and function with the mutant [-1584G] promoter type being consistently associated with significantly higher expression than [-1584C]. To investigate functional differences between the detected variant protein forms CYP2D6.1, 2D6.2, 2D6.9 and 2D6.10, we expressed them recombinantly in insect cells. The most significant difference was a decrease in the relative P450 holoprotein content of all allelic forms, including the common functional variant 2D6.2, in comparison to 2D6.1, whereas only modest Km changes were observed. Taken together, these data provide further insight into the complex mechanisms that govern the highly variable expression and function of CYP2D6.

Characterisation of retention in micellar high-performance liquid chromatography, in micellar electrokinetic chromatography and in micellar electrokinetic chromatography with reduced flow

The retention (migration) behaviour of various barbiturates, phenylurea and triazine herbicides in micellar electrokinetic chromatography (MEKC) with uncoated fused-silica capillaries was compared with the behaviour in micellar electrokinetic chromatography with reduced electroosmotic flow (RF-MEKC) using capillaries modified with linear polyacrylamide. The error in the values of the retention factors caused by the neglection of the contribution of the electroosmotic flow in RF-MEKC was investigated and a method for correcting this error was suggested. The retention was characterised using the lipophilic and polar indices to characterise and to predict the retention as a function of the concentration of the surfactant (sodium dodecylsulphate) in the running buffer in MEKC and in RF-MEKC. Homologous series of n-alkylbenzenes and of n-alkan-2-ones were compared as the standard sets for the calibration of the retention (migration) index scale. The values of the lipophilic indices of a given solute measured in reversed-phase HPLC, MEKC and RF-MEKC are close to each other. Under ideal MEKC conditions, the values of the polarity indices are close to one for various sample solutes. However, for partially ionised compounds such as weakly acidic barbiturates, where the contribution of the electrophoretic migration is significant, the values of the polarity indices are significantly lower than one. Optimum conditions for separations of mixtures of triazine and phenylurea herbicides and of barbiturates using various techniques tested were compared.

Alkyl and aryl substituted corroles. 1. Synthesis and characterization of free base and cobalt containing derivatives. x-ray structure of (Me(4)Ph(5)Cor)Co(py)(2)

The synthesis, spectroscopic properties, and electrochemistry of six different alkyl- and aryl-substituted Co(III) corroles are presented. The investigated compounds contain methyl, ethyl, phenyl, or substituted phenyl groups at the eight beta-positions of the corrole macrocycle and four derivatives also contain a phenyl group at the 10-meso position of the macrocycle. Each cobalt corrole undergoes four reversible oxidations in CH(2)Cl(2) containing 0.1 M tetra-n-butylammonium perchlorate and exists as a dimer in its singly and doubly oxidized forms. The difference in potential between the first two oxidations is associated with the degree of interaction between the two corrole units of the dimer and ranges from an upper value of 0.62 V, in the case of (Me(6)Et(2)Cor)Co, to a lower value of about 0.17 V, in the case of four compounds which have a phenyl group located at the 10-meso position of the macrocycle. These Co(III) corroles strongly coordinate two pyridine molecules or one carbon monoxide molecule in CH(2)Cl(2) media, and ligand binding constants were evaluated using spectroscopic and electrochemical methods. The structure of (Me(4)Ph(5)Cor)Co(py)(2) was also determined by X-ray diffraction. Crystal data: (Me(4)Ph(5)Cor)Co(py)(2).3CH(2)Cl(2).H(2)O, orthorhombic, a = 19.5690(4) A, b = 17.1070(6) A, c = 15.9160(6) A, V = 5328.2(5) A(3), space group Pna2(1), Z = 2, 35 460 observations, R(F) = 0.069.

Alkyl and aryl substituted corroles. 2. Synthesis and characterization of linked "face-to-face" biscorroles. X-ray structure of (BCA)Co(2)(py)(3), where BCA represents a biscorrole with an anthracenyl bridge

The synthesis, spectroscopic properties, and electrochemistry of (BCA)Co(2) and (BCB)Co(2) are described where BCA and BCB represent biscorroles linked by an anthracenyl (A) or a biphenylenyl (B) bridge. The pyridine and CO binding properties of (BCA)Co(2) and (BCB)Co(2) are also presented, and one of the compounds in its pyridine-ligated form, (BCA)Co(2)(py)(3), is structurally characterized. The data on the biscorroles are compared on one hand to the monocorrole having the same substitution pattern and on the other hand to bisporphyrins having two Co(II) ions and the same anthracenyl or biphenylenyl linkers in order to better understand the interaction which occurs between the two corrole macrocycles. A parallel study on five different Co(III) phenyl-substituted corroles showed that bis-pyridine and mono-CO adducts are readily formed from the complexes in CH(2)Cl(2). This present paper examines how the ligand binding properties and electrochemistry of these Co(III) corroles are modified by the anthracenyl or biphenylenyl bridge which links the two macrocycles in a face to face orientation. An X-ray crystal structure was obtained for the tris-pyridine adduct of the anthracenyl bridged derivative, (BCA)Co(2)(py)(3), and gives the following results: C(127)H(99)Co(2)N(11).2CHCl(3), M = 2135.90, triclinic, space group P&onemacr;, a = 13.2555(5) A, b = 18.6406(8) A, c = 22.2140(9) A, alpha = 94.186(9) degrees, beta = 102.273(9) degrees, gamma = 94.205(9) degrees, V = 5326.8(4) A(3), 9293 independent reflections collected, R(F) = 0.066.

Hypermethylation of the tumor necrosis factor receptor superfamily 6 (APT1, Fas, CD95/Apo-1) gene promoter at rel/nuclear factor kappaB sites in prostatic carcinoma

DNA hypermethylation of CpG-rich promoter sequences is associated with tumor suppressor gene inactivation in many human cancers, notably in carcinoma of the prostate and the urinary bladder. Recently, the mouse homologue of the tumor necrosis factor receptor superfamily 6 (TNFRSF6) gene was reported to be inactivated by DNA methylation in various cell types. The Fas (CD95, Apo-1) protein encoded by the TNFRSF6 gene is an important mediator of apoptosis, which also is downregulated in different types of human carcinoma. We therefore investigated the methylation of the TNFRSF6 promoter in prostatic and bladder carcinomas and cell lines. In a restriction enzyme polymerase chain reaction assay, four of 32 prostatic carcinomas and three of 15 advanced bladder carcinomas showed evidence of hypermethylation at the rel/nuclear factor kappaB (NFkappaB) binding sites essential for promoter activity. The DU145 cell line derived from a metastasis of a prostate carcinoma also displayed hypermethylation in this assay, which was confirmed by bisulfite sequencing. Treatment of DU145 cells with the methylation inhibitor deoxyazacytidine slightly increased Fas protein expression, as detected by flow cytometry analysis. In vitro methylation of the TNFRSF6 promoter at the rel/NFkappaB sites completely abolished its activity. Thus, although the TNFRSF6 gene can be inactivated efficiently by DNA methylation, hypermethylation occurs neither frequently nor extensively in human carcinomas and appears to play a limited role in downregulation of Fas expression.

Timing of analog research in medicinal chemistry

Analog research plays an important role in medicinal chemistry. Having identified a new target in molecular biology many similar lead compounds are synthesized resulting in closely related products on the market. Another approach is the further optimising of an existing drug in order to improve on the original. In some cases these two approaches overlap. The question of timing and the importance of analog research are analyzed in this paper.

The suitability of hepatocyte culture models to study various aspects of drug metabolism

Since the liver is the main organ involved in the metabolism and the toxicity of xenobiotics, isolated rat hepatocytes have been increasingly used in recent years as a model to identify pharmacological and toxicological responses of drugs. However, it is generally recognised that isolated hepatocytes retain most of their functions only for a short period. For this reason, numerous models and techniques have been developed to study and improve the metabolic capacity of hepatocytes in vitro over an extended time period and in application for drug metabolism studies. In the present study, we compared four different cell culture models to fulfill these requirements and have therefore harvested hepatocytes and cultured them in different culture systems over two weeks. In order to prove certain advantages or disadvantages of each model, we compared the metabolic capacity, albumin secretion, the release of cytosolic and mitochondrial enzymes, as well as the capacity to metabolise diclofenac (DF). We found that rat hepatocytes in all studied culture models (except the Unisyn Bioreactor) were able to metabolise DF to the same extent as found in vivo. However, the concentration of metabolites was found to decrease with culture time using the monolayer although the DF metabolite level in the collagen Sandwich culture was higher than that of the monolayer culture. The 3D-membrane bioreactor preserved the metabolic capacity for a prolonged period of time. The concentrations of DF metabolites in the Unisyn hollow fiber bioreactor were below the detection limit, which corresponded to other parameters such as albumin secretion and cytochrome P450 activity, disqualifying this culture system clearly for the use of in vitro primary hepatocyte cultures. The other three systems all have their place in drug metabolism with different advantages. However, our studies clearly showed that hepatocytes cultured within a collagen sandwich or in the 3D-membrane bioreactor qualify to study various aspects of drug metabolisms over a long time period. Further studies are needed to prove if the later two culture models may really help to reduce animal testing.

Hounsfield unit density in the determination of urinary stone composition

OBJECTIVES

Noncontrast computed tomography (NCCT) has emerged as the diagnostic study of choice in the evaluation of acute flank pain. Recent in vitro studies have suggested that NCCT can be used to predict the composition of urinary stones on the basis of differences in radiodensity (measured in Hounsfield units, HUs). We sought to determine whether the analysis of in vivo urinary stones seen on NCCT could predict their composition.

METHODS

Between March 1997 and August 1999, 100 pure stones from patients seen at the Wilford Hall Medical Center in San Antonio, Texas were submitted for analysis. All had been visualized by NCCT before stone passage or retrieval. A General Electric High-Speed Advantage CT scanner evaluated most of these patients by a "flank pain protocol" (ie, helical technique with breath-holding at 120 kV, 200 mA with 5 mm collimation). Each scan was interpreted by one of two staff radiologists who measured the HUs for each stone. A statistical comparison was made between the stone composition and radiodensity. To allow for subsequently observed increases in radiodensity with increasing stone size regardless of composition, the HU value was divided by each stone's largest transverse diameter in millimeters to give the HU density. A statistical comparison was then made between stone composition and HU density.

RESULTS

No significant difference was noted between the HU values of calcium oxalate and calcium phosphate stones, and thus they were analyzed collectively as "calcium stones." When the HU values of calcium (n = 87), uric acid (n = 7), struvite (n = 4), and cystine (n = 2) stones were compared, the overlap of ranges precluded accurate identification, and the mean HU values were not significantly different from one another. There was less overlap noted when comparing the HU densities of the stones studied, and no noncalcium stone had an HU density greater than 76 HU/mm. Using one-way analysis of variance, significant differences were noted between the mean HU density of calcium (105 +/- 43) and uric acid (50 +/- 24) stones (P = 0.006). A trend toward significance was found between the mean HU density of the calcium and struvite stones (53 +/- 28, P = 0.073). No significant differences were found among the other stones.

CONCLUSIONS

HU density compared with the HU value alone better characterized differences in radiodensities among urinary stones; calcium stones can be distinguished from uric acid stones on the basis of this value. However, neither the HU density nor the mean HU value was able to identify urinary stones in vivo.

A prognostic index for 30-day mortality after stroke

The objective of this study was to develop a simplified scoring system to predict 30-day mortality in patients with acute ischemic stroke. A retrospective cohort study was performed in a tertiary referral hospital in the Hunter Region of Australia. A prognostic index was created by assigning points to the variables in a Cox model. The index included impaired consciousness (5 points), dysphagia (3 points), urinary incontinence (4 points), admission body temperature higher than 36.5 degrees C (2 points), and hyperglycemia without a clinical history of diabetes (2 points). A score of 11 or more defined a high-risk group. The index achieved a sensitivity, specificity, and positive predictive value of 68%, 98% and 75%, respectively, in the derivation sample and 57%, 97% and 68%, respectively, in the validation sample. The results provide a simple risk stratification instrument for clinical research and practice. Further evaluation of the model in a prospective cohort is warranted

Allelic loss at 10q23.3 but lack of mutation of PTEN/MMAC1 in chromophobe renal cell carcinoma

Chromophobe renal cell carcinoma (RCC) is characterized by loss of multiple chromosomes including chromosome 10. This study was undertaken to determine the LOH at the PTEN/MMAC1 locus (chromosome band 10q23.3) and to search for gene mutations in 15 chromophobe, 50 conventional, and 10 papillary RCCs as well as in 10 renal oncocytomas. Loss of heterozygosity (LOH) wa seen at all informative loci in all chromophobe RCCs and in two conventional RCCs. We did not find mutations by analyzing exon 1 to 9 of the PTEN/MMAC1 gene using the PCR-SSCP technique in tumors with LOH at 10q23.3.

Video-intuboscopic assistance is a useful aid to tracheal intubation in pediatric patients

PURPOSE

To evaluate the efficacy of video-intuboscopic assisted tracheal intubation in a difficult intubation setting.

METHODS

In 50 pediatric patients (mean age 12.8 +/- 3.1 yr, range 6-16 yr) a grade 3 direct laryngoscopic view was simulated. Eight certified registered nurse anesthetists without experience in endoscopic intubation performed tracheal intubation on five or more patients using the video-optical intubation stylet. Time from insertion of the tube into the oral cavity until the tip had passed the vocal cords was recorded. Failed intubation was defined as intubation >60 sec, arterial oxygen saturation <92% or esophageal intubation. Subjective degree of difficulty was asked from the operators using a Likert-scale.

RESULTS

Forty-six of the 50 patients were successfully intubated within 60 sec and without arterial oxygen desaturation. In four patients, video-assisted tracheal intubation failed due to prolonged intubation time. Intubation times ranged from 10-40 sec (median 15 sec). Mean intubation time in the first patient (24.5 +/- 17.3 sec) appeared longer than for the fifth patient (20.8 +/- 10.9 sec), but the difference was not statistically significant (P=0.87). Mean estimated degree of difficulty was 3.9 +/- 2.1. Subjective estimates of difficulty increased with intubation times (P=0.001).

CONCLUSION

The video-optical intubation stylet can be considered a valuable aid for tracheal intubation in pediatric patients with a difficult airway.

Detailed deletion mapping in sporadic breast cancer at chromosomal region 17p13 distal to the TP53 gene: association with clinicopathological parameters

Chromosome 17p is among the most frequently deleted regions in a variety of human malignancies including breast cancer. This study has further refined the localization of a putative tumour suppressor gene (TSG) at 17p13 distal to the TP53 gene in breast carcinomas. It was found that 73% (37 of 51) of the breast tumours exhibited loss of heterozygosity (LOH) at one or more loci at 17p13. The allelic loss patterns of these tumours suggest the presence of at least seven commonly deleted regions on 17p13. The three most frequently deleted regions were mapped at chromosomal location 17p13.3-17p13.2 between the markers D17S831 and D17S1845 (56% LOH), at 17p13.1 between D17S1810 and D17S1832 (53% LOH), and at 17p13.1 between D17S938 and TP53 (55% LOH). A significant correlation was found between loss at 17p13 and tumour grade, size, proliferative activity, and oestrogen receptor (ER) status. Losses at 17p13 were seen more frequently in large and poorly differentiated tumours with high proliferative activity. These data support and extend previous reports on the presence of a putative TSG(s) at chromosomal region 17p13 distal to the TP53 gene and show that different subsets of LOH are associated with more aggressive tumour behaviour.

Extensive genetic polymorphism in the human CYP2B6 gene with impact on expression and function in human liver

The human cytochrome P450, CYP2B6, is involved in the metabolism of several therapeutically important drugs and environmental or abused toxicants. In this study, we present the first systematic investigation of genetic polymorphism in the CYP2B6 gene on chromosome 19. A specific direct sequencing strategy was developed based on CYP2B6 and CYP2B7 genomic sequence information and DNA from 35 subjects was completely analysed for mutations throughout all nine exons and their exon-intron boundaries. A total of nine novel point mutations were identified, of which five result in amino acid substitutions in exon 1 (C64T, Arg22Cys), exon 4 (G516T, Gln172His), exon 5 (C777A, Ser259Arg and A785G, Lys262Arg) and exon 9 (C1459T, Arg487Cys) and four are silent mutations (C78T, G216C, G714A and C732T). Polymerase chain reaction-restriction fragment length polymorphism tests were developed to detect each of the five nonsynonymous mutations in genomic DNA. By screening a population of 215 subjects the C64T, G516T, C777A, A785G and C1459T mutations were found at frequencies of 5.3%, 28.6%, 0.5%, 32.6% and 14.0%, respectively. Haplotype analysis revealed six different mutant alleles termed CYP2B6*2 (C64T), *3 (C777A), *4 (A785G), *5 (C1459T), *6 (G516T and A785G) and *7 (G516T, A785G and C1459T). By analysing a large number of human liver samples, significantly reduced CYP2B6 protein expression and S-mephenytoin N-demethylase activity were found in carriers of the C1459T (R487C) mutation (alleles *5 and *7). These data demonstrate that the extensive interindividual variability of CYP2B6 expression and function is not only due to regulatory phenomena, but also caused by a common genetic polymorphism.

Evaluation of a simple method for minimizing iatrogenic blood loss from discard volumes in critically ill newborns and children

OBJECTIVE

To validate a simple method avoiding discard volumes in pediatric patients with indwelling arterial and venous lines.

DESIGN

Zero-discarding was achieved by passive extracorporeal arteriovenous backflow via standard single pressure transducer equipment. We tested backflow distances (10, 20 and 30 cm beyond the sampling port), corresponding to withdrawal volumes of 0.6 ml, 0.8 ml and 1.0 ml, respectively, in comparison to conventional sampling with discard of 0.6 ml. With the backflow technique, the "withdrawal volume" was flushed back to the patient after sampling. We enrolled 120 patients who were allocated to either of the following paired sampling procedures: 10 cm versus conventional, 20 cm versus conventional, 30 cm versus conventional and two paired conventional samples. The order of the sampling was randomly allocated. Bias and precision were determined using Bland-Altman diagrams and algorithms.

RESULTS

No appreciable difference was found for blood gases, hemoglobin, potassium and calcium between the backflow technique and conventional sampling. Sodium results and blood glucose showed a bias towards higher values with the backflow technique (mean difference, sodium, 0.9 mmol/l; glucose, mean difference 0.5 mmol/l, standard deviation 0.44 mmol/l).

CONCLUSIONS

The backflow technique provides reliable results for blood gases and electrolytes. However, in patients at risk of hypoglycemia, the backflow method should not be used to monitor blood glucose levels.

The C3435T mutation in the human MDR1 gene is associated with altered efflux of the P-glycoprotein substrate rhodamine 123 from CD56+ natural killer cells

P-glycoprotein (PGP) is a membrane protein which determines drug disposition in humans (e.g. digoxin). It is also expressed in various leukocyte lineages with highest expression in CD56+ natural killer cells. Recently, a polymorphism in exon 26 (C3435T) of this gene was shown to correlate with intestinal PGP expression and function in humans. Carriers homozygous for this polymorphism (TT) showed more than two-fold lower PGP expression and higher digoxin plasma concentrations compared to the CC group. However, it is not known whether this mutation in the MDR1 gene is also associated with altered PGP function in peripheral blood cells. We therefore assessed efflux of the PGP-substrate rhodamine 123 from CD56+ natural killer cells. Leukocytes were isolated from whole blood of 10 CC, 10 CT and 11 TT healthy Caucasian individuals. Using flow cytometry, rhodamine fluorescence was determined in CD56+ cells. Moreover, MDRI mRNA was quantified in leukocytes by real-time polymerase chain reaction. Subjects with CC genotype revealed a significantly lower rhodamine fluorescence (i.e. higher PGP function) compared to individuals with TT genotype (51.1 +/- 11.4% versus 67.5 +/- 9.5%, p < 0.01). Heterozygous individuals had an intermediate rhodamine fluorescence (61.4 +/- 6.3%). MDR1 mRNA normalized for cyclophilin was lowest in the TT population (1.29 +/- 1.01), intermediate in heterozygous subjects (1.60 +/- 0.76) and highest in the CC group (1.91 +/- 0.94; not significant). In summary, subjects being homozygous for C in position 3435 of the MDR1 gene have a more pronounced efflux of rhodamine from CD56+ natural killer cells and a higher MDR1 mRNA expression in leukocytes than subjects with the TT genotype. Measurement of rhodamine efflux using flow-cytometry from peripheral blood cells allows assessment of genetically determined differences in P-glycoprotein function.

Distribution and ultrastructure of tachykinin-like immunoreactivity in the frog (Rana esculenta) spinal cord, notably, the dorsal horn

Tachykinins are involved in pain transmission at the spinal level. In frog, at least four tachykinins [TK] have been isolated from the brain, but their organization in the dorsal horn of the spinal cord is still poorly known. We have reexamined TK distribution by immunocytochemistry using an antibody recognizing the sequence common to all tachykinins in the spinal cord and dorsal root ganglia of the green frog Rana esculenta. A dense tachykinin-like immunoreactivity (TK-LI) was observed in the dorsolateral fasciculus or Lissauer's tract running ventromedial to the entry of the dorsal root and in numerous small and medium-sized dorsal root ganglion cells showing a primary afferent origin for part of TK-LI of the dorsal horn. The observation of numerous cell bodies in the dorsal horn, in addition, suggested a local or propriospinal origin. One group of cells was localized at the entrance of the Lissauer's tract TK-LI fibers into the dorsal horn, and another group was localized in the upper dorsal horn, a region with a low density of TK-LI fibers. It was suggested that the latter group may correspond to neurokinin B. Electron microscopic examination of the Lissauer's tract showed numerous immunoreactive axons, some located at the center of glomerular-like arrangements, suggesting that the information brought by these fibers may be transmitted and most probably modulated before their entry in the dorsal horn. In conclusion, the functional organization of tachykinins in the frog spinal cord seems to be similar to that of mammals, albeit with a different morphological organization.

Evaluation of the FASTSTART mode for reducing start-up delay in syringe pump infusion systems

OBJECTIVE

The aim of the study was to evaluate the IVAC P7000 FASTSTART mode with regard to start-up performance in a 50-ml infusion syringe at a flow rate of 1 ml.h-1.

METHODS

The time from depression of the start button to first fluid flow (T1) and to establishment of a pre-set flow rate (T2) were gravimetrically recorded with and without FASTSTART and with and without priming of the infusion system with a 1-ml fluid bolus prior to connection of the infusion line to the patient.

RESULTS

FASTSTART significantly reduced start-up times in the unprimed syringe pump infusion system from (mean [SD]) 9.4 (6.0) to 2.5 (3.5) min for T1 and from 21.8 (9.8) to 9.4 (6.2) min for T2 (all p < 0.001). The greatest improvement in shortening of T1 and T2 was obtained when the system was primed prior to starting (p < 0.0001). After priming the infusion system, FASTSTART shortened T2 by some 50% from 1.4 (1.4) to 0.7 (0.6) min.

CONCLUSION

Our data indicate that the FASTSTART procedure is effective and that substantial improvements can be obtained by priming the system prior to starting.

Evaluation of the FASTSTART mode for reducing start-up delay in syringe pump infusion systems

OBJECTIVE

The aim of the study was to evaluate the IVAC P7000 FASTSTART mode with regard to start-up performance in a 50-ml infusion syringe at a flow rate of 1 ml.h-1.

METHODS

The time from depression of the start button to first fluid flow (T1) and to establishment of a pre-set flow rate (T2) were gravimetrically recorded with and without FASTSTART and with and without priming of the infusion system with a 1-ml fluid bolus prior to connection of the infusion line to the patient.

RESULTS

FASTSTART significantly reduced start-up times in the unprimed syringe pump infusion system from (mean [SD]) 9.4 (6.0) to 2.5 (3.5) min for T1 and from 21.8 (9.8) to 9.4 (6.2) min for T2 (all p < 0.001). The greatest improvement in shortening of T1 and T2 was obtained when the system was primed prior to starting (p < 0.0001). After priming the infusion system, FASTSTART shortened T2 by some 50% from 1.4 (1.4) to 0.7 (0.6) min.

CONCLUSION

Our data indicate that the FASTSTART procedure is effective and that substantial improvements can be obtained by priming the system prior to starting.

Diagnosis and monitoring of murine histoplasmosis by a nested PCR assay

A newly developed nested PCR assay was applied to murine models of histoplasmosis. ICR and BALB/c mice were intravenously infected with Histoplasma capsulatum and sacrificed up to 29 days later. Samples of blood, spleen, and lung homogenates were cultured and examined by the PCR assay. In the ICR mouse model, 265 of 319 organ samples showed concordant results. With 7 samples, the culture was positive and the PCR assay was negative whereas a positive PCR but a negative culture were obtained with 47 samples (P < 0.0001 according to McNemar's test). Organ homogenates and blood samples of either spontaneously cured or treated BALB/c mice were PCR negative. The nested PCR assay performs excellently in the monitoring of spontaneously and treatment-cured murine histoplasmosis. It limits the infection risks of the laboratory staff and might be of diagnostic value for humans.

Mutations in the gene encoding SLURP-1 in Mal de Meleda

Mal de Meleda (MDM) is a rare autosomal recessive skin disorder, characterized by transgressive palmoplantar keratoderma (PPK), keratotic skin lesions, perioral erythema, brachydactyly and nail abnormalities. We report the refinement of our previously described interval of MDM on chromosome 8qter, and the identification of mutations in affected individuals in the ARS (component B) gene, encoding a protein named SLURP-1, for secreted Ly-6/uPAR related protein 1. This protein is a member of the Ly-6/uPAR superfamily, in which most members have been localized in a cluster on chromosome 8q24.3. The amino acid composition of SLURP-1 is homologous to that of toxins such as frog cytotoxin and snake venom neurotoxins and cardiotoxins. Three different homozygous mutations (a deletion, a nonsense and a splice site mutation) were detected in 19 families of Algerian and Croatian origin, suggesting founder effects. Moreover, one of the common haplotypes presenting the same mutation was shared by families from both populations. Secreted and receptor proteins of the Ly-6/uPAR superfamily have been implicated in transmembrane signal transduction, cell activation and cell adhesion. This is the first instance of a secreted protein being involved in a PPK.