Sustainable surgical resource initiative for Haiti: the SSRI-Haiti project

In response to the 2010 earthquake and subsequent cholera epidemic, St Luke's Medical Center was established in Port-au-Prince, Haiti. Here, we describe its inception and evolution to include an intensive care unit and two operating rooms, as well as the staffing, training and experiential learning activities, which helped St Luke's become a sustainable surgical resource. We describe a three-phase model for establishing a sustainable surgical centre in Haiti (build facility and acquire equipment; train staff and perform surgeries; provide continued education and expansion including regular specialist trips) and we report a progressive increase in the number and complexity of cases performed by all-Haitian staff from 2012 to 2022. The results are generalised in the context of the 'delay framework' to global health along with a discussion of the application of this three-phase model to resource-limited environments. We conclude with a brief description of the formation of a remote surgical centre in Port-Salut, an unforeseen benefit of local competence and independence. Establishing sustainable and collaborative surgery centres operated by local staff accelerates the ability of resource-limited countries to meet high surgical burdens.

SHock-INduced Endotheliopathy (SHINE): A mechanistic justification for viscoelastography-guided resuscitation of traumatic and non-traumatic shock

Irrespective of the reason for hypoperfusion, hypocoagulable and/or hyperfibrinolytic hemostatic aberrancies afflict up to one-quarter of critically ill patients in shock. Intensivists and traumatologists have embraced the concept of SHock-INduced Endotheliopathy (SHINE) as a foundational derangement in progressive shock wherein sympatho-adrenal activation may cause systemic endothelial injury. The pro-thrombotic endothelium lends to micro-thrombosis, enacting a cycle of worsening perfusion and increasing catecholamines, endothelial injury, de-endothelialization, and multiple organ failure. The hypocoagulable/hyperfibrinolytic hemostatic phenotype is thought to be driven by endothelial release of anti-thrombogenic mediators to the bloodstream and perivascular sympathetic nerve release of tissue plasminogen activator directly into the microvasculature. In the shock state, this hemostatic phenotype may be a counterbalancing, yet maladaptive, attempt to restore blood flow against a systemically pro-thrombotic endothelium and increased blood viscosity. We therefore review endothelial physiology with emphasis on glycocalyx function, unique biomarkers, and coagulofibrinolytic mediators, setting the stage for understanding the pathophysiology and hemostatic phenotypes of SHINE in various etiologies of shock. We propose that the hyperfibrinolytic phenotype is exemplified in progressive shock whether related to trauma-induced coagulopathy, sepsis-induced coagulopathy, or post-cardiac arrest syndrome-associated coagulopathy. Regardless of the initial insult, SHINE appears to be a catecholamine-driven entity which early in the disease course may manifest as hyper- or hypocoagulopathic and hyper- or hypofibrinolytic hemostatic imbalance. Moreover, these hemostatic derangements may rapidly evolve along the thrombohemorrhagic spectrum depending on the etiology, timing, and methods of resuscitation. Given the intricate hemochemical makeup and changes during these shock states, macroscopic whole blood tests of coagulative kinetics and clot strength serve as clinically useful and simple means for hemostasis phenotyping. We suggest that viscoelastic hemostatic assays such as thromboelastography (TEG) and rotational thromboelastometry (ROTEM) are currently the most applicable clinical tools for assaying global hemostatic function-including fibrinolysis-to enable dynamic resuscitation with blood products and hemostatic adjuncts for those patients with thrombotic and/or hemorrhagic complications in shock states.

Universal Anesthesia Machine: Clinical Application in an Austere, Resource-Limited Environment

INTRODUCTION

In austere environments, the safe administration of anesthesia becomes challenging because of unreliable electrical sources, limited amounts of compressed gas, and insufficient machine maintenance capabilities. Such austere environments exist in battlefield medicine, in low- and middle-income countries (LMICs), and in areas struck by natural disasters. Whether in military operations or civilian settings, the Universal Anesthesia Machine (UAM) (Gradian Health Systems, New York, New York) is a draw-over device capable of providing safe and effective general anesthesia when external oxygen supplies or reliable electrical sources are limited. This brief report discusses a proof-of-concept observational study demonstrating the clinical utility of the UAM in a resource-limited area.

MATERIALS AND METHODS

This observational study of 20 patients in Haiti who underwent general anesthesia using the UAM highlights the device's capability to deliver anesthesia intraoperatively in a resource-limited LMIC clinical setting. Preoxygenation was achieved with the UAM's draw-over oxygen supply. Patients received acetaminophen for analgesia, dexmedetomidine for preinduction anesthesia, and succinylcholine for paralysis. After induction, the UAM provided a mixture of oxygen and isoflurane for maintenance of anesthesia. Manual ventilation was performed using draw-over bellows until spontaneous ventilation recurred, when clinically appropriate, artificial airways were removed. Intraoperative medication was administered at the anesthesiologist's discretion. The institutional review board at the U.S. anesthesiologists' affiliated institution and the Haitian hospital approved this study; patients were consented in their native language.

RESULTS

Two anesthesiologists used the UAM to deliver general anesthesia to 20 patients in a Haitian hospital without access to an external oxygen supply, reliable power grid, or opioids. The patients' average age was ~40 years, and 90% of them were male. Most of the cases were herniorrhaphy (50%) and hydrocelectomy (25%) surgeries. The median American Society of Anesthesiologists (ASA) score was 2; 45% of the patients had an ASA score of 1, and none had an ASA score >3. Of the 20 cases, 55% of patients received an endotracheal tube, and 40% received a laryngeal mask airway; for one patient, only a masked airway was used. Every patient was discharged on the day of the surgery. No complications occurred in the perioperative or 1-month follow-up period.

CONCLUSION

The UAM can be used where a lack of resources and training exist because of its simple design, built-in oxygen concentrator, and capacity to revert from continuous-flow to draw-over anesthesia in the event of a power failure or if external oxygen supplies are unavailable. We believe the UAM addresses some of the shortcomings of modern anesthesia machines and has the potential to improve the delivery of safe general anesthesia in combat and austere scenarios. Further studies could consider different types of surgeries than those reported here and involve more complex patients. Studies involving alternative anesthetic agents and non-anesthesiologist personnel are also needed. Overall, this brief report detailing the use of the UAM following a natural disaster in a LMIC is proof of concept that the machine can provide reliable anesthesia for surgical procedures in austere and resource-limited environments, including disaster areas and modern combat zones.

Plasma temperature measurement with a silicon photomultiplier (SiPM)

The temperature of a nonneutral plasma confined in a Penning-Malmberg trap can be determined by slowly lowering one side of the trap's electrostatic axial confinement barrier; the temperature is inferred from the rate at which particles escape the trap as a function of the barrier height. In many experiments, the escaping particles are directed toward a microchannel plate, and the resulting amplified charge is collected on a phosphor screen. The screen is used for imaging the plasma but can also be used as a Faraday cup (FC) for a temperature measurement. The sensitivity limit is then set by microphonic noise enhanced by the screen's high-voltage bias. Alternately, a silicon photomultiplier (SiPM) can be employed to measure the charge via the light emitted from the phosphor screen. This decouples the signal from the microphonic noise and allows the temperature of colder and smaller plasmas to be measured than could be measured previously; this paper focuses on the advantages of a SiPM over a FC.

Whole Blood for Civilian Urban Trauma Resuscitation: Historical, Present, and Future Considerations

Whole blood (WB) has been used for more than a century for far-forward combat resuscitation. Following the Iraq/Afghanistan combat, maritime, and austere environment use of WB for the resuscitation of severely hemorrhaging patients, there has been an increasing use of WB for the civilian urban resuscitation environment population. The impetus for this was not just improved outcomes in far-forward hospitals, which had different populations and different needs than the civilian urban population, but also an application of the lessons suggested by recent 1:1:1 plasma:platelets:packed red cells fixed-ratio studies for patients with massive transfusion needs. Mechanistic, logistic, and standardization concerns have been addressed and are evolving as the WB project advances. A small number of studies have been published on WB in the civilian urban trauma population. In addition, European experience with viscoelastic testing and resuscitation with fibrinogen and prothrombin complex concentrate has provided another viewpoint regarding the choice of resuscitation strategies for severely bleeding trauma patients in urban civilian environments. There are randomized controlled trials in process, which are testing the hypothesis that WB may be beneficial for the civilian urban population. Whether WB will improve mortality significantly is now a matter of intense study, and this commentary reviews the history, mechanistic foundations, and logistical aspects for the use of WB in the civilian trauma population.

A Case of Successful Thromboelastographic Guided Resuscitation after Postpartum Hemorrhage and Cardiac Arrest

Amniotic fluid embolism (AFE) is an unusual cause of life threatening peri partum hemorrhage (PPH). AFE resuscitation is often associated with renal and respiratory insufficiency, and a coagulopathy similar to disseminated intravascular coagulation (DIC). Resuscitation requires immediate recognition and limited use of crystalloid. We present a case of PPH caused by AFE with resultant cardiac arrest, renal and respiratory failure, and DIC-like coagulopathy, whose successful resuscitation was guided by perfusionist-directed serial thromboelastography (TEG). Viscoelastic tests (VET)s, including the TEG and rotational thromboelastometry (ROTEM), may provide more individualized blood component therapy (BCT) in the treatment of severe PPH associated with AFE as has been previously noted with trauma resuscitation in the literature. However, VET's efficacy is often limited by a lack of standardization, quality assurance norms, and consistent operator proficiency. We suggest that there may be a role for perfusionsts adept at utilizing TEG in the optimization of BCT and adjunctive hemostatic agents in severely hemorrhagic patients. This patient's successful resuscitation demonstrates the importance of resuscitation guided by the perfusionist or other medical professionals with expertise in TEG guided resuscitation and how the administration of specific blood products and hemostatic agents guided by the TEG can help optimize patient outcomes in comparison to traditional 1:1:1 packed red blood cells (PRBC) /fresh frozen plasma (FFP) /platelets ratios given to severely hemorrhaging patients.

Tiered approaches to chromatographic bioanalytical method performance evaluation: recommendation for best practices and harmonization from the Global Bioanalysis Consortium harmonization team

The A2 harmonization team, a part of the Global Bioanalysis Consortium (GBC), focused on defining possible tiers of chromatographic-based bioanalytical method performance. The need for developing bioanalytical methods suitable for the intended use is not a new proposal and is already referenced in regulatory guidance language. However, the practical implementation of approaches that differ from the well-established full validation requirements has proven challenging. Advances in technologies, the need to progress drug development more efficiently, and emerging new drug compound classes support the use of categorized tiers of bioanalytical methods. This paper incorporated the input from an international team of experienced bioanalysts to surmise the advantages and the challenges of tiered approaches and to provide recommendations on paths forward.

Low energy prepulse for 10 Hz operation of a soft-x-ray laser

The influence on Nickel-like Molybdenum soft-x-ray laser performance and stability of a low energy laser prepulse arriving prior to the main laser pumping pulses is experimentally investigated. A promising regime for 10 Hz operation has been observed. A four times increase in soft-x-ray laser operation time with a same target surface is demonstrated. This soft-x-ray laser operation mode corresponds to an optimum delay between the prepulse and the main pulses and to a prepulse energy greater than 20 mJ. We also show that this regime is not associated with a weaker degradation of the target or any reduced ablation rate. Therefore the role of preplasma density gradient in this effect is discussed.

Evidence for parent-of-origin effects on genetic variability of beef traits

Imprinted genes are involved in many aspects of development in mammals, plants, and perhaps birds and may play a role in growth and carcass composition of slaughter animals. In the presence of genomic imprinting the expression and, consequently, the effect on the phenotype of maternal and paternal alleles are different. For genetic evaluation genomic imprinting can be accounted for by incorporating 2 additive genetic effects per animal; the first corresponds to a paternal and the second to a maternal expression pattern of imprinted genes. This model holds whatever the mode of imprinting may be: paternal or maternal, full or partial, or any combination thereof. A set of slaughter data from 65,233 German Simmental fattening bulls was analyzed with respect to the relative importance of the genetic imprinting variance. Besides slaughter weight, net daily BW gain, and killing out percentage, there were 22 other traits describing the carcass composition. The latter traits were evaluated by automatic video-imaging devices and were composed of weights of valuable cuts as well as fat and meatiness grade. The number of ancestors in the pedigree was 356,880. Genomic imprinting significantly contributed to the genetic variance of 10 traits, with estimated proportions between 8 and 25% of the total additive genetic variance. For 6 of these traits, the maternal contribution to the imprinting variance was larger than the paternal, whereas for all other traits the reverse was true. Fat grade only showed a paternal contribution to the imprinting variance. Estimates of animal model heritabilities of automatic video-imaging-recorded carcass traits ranged between 20 and 30%.

Inhibition of p53 transcriptional activity by the S100B calcium-binding protein

The levels of S100 Ca(2+)-binding proteins correlate with the progression of certain tumors, but their role, if any, in carcinogenesis is still poorly understood. S100B protein associates with both the p53 oligomerization domain (residues 325-355) and the extreme C terminus of the tumor suppressor p53 (residues 367-392). Consequently, S100B inhibits p53 tetramer formation and p53 phosphorylation mediated by protein kinase C, on p53 C-terminal end. In this report, we show that the S100B protein decreases p53 DNA binding and transcriptional activity. The effect of S100B is reflected in vivo by a reduced accumulation of p53, p21, and MDM2 protein levels in co-transfection assays and in response to bleomycin. The S100B can still interact with p53 in the absence of p53 extreme C-terminal end and reduce the expression of p53 downstream effector genes. These data indicate that S100B does not require p53 extreme C-terminal end to inhibit p53 activity. Collectively, these findings imply that elevated levels of S100B in tumors such as astrocytomas and gliomas could inhibit p53 functions and contribute to cancer progression.

Development, validation and application of assays to quantify metrifonate and 2,2-dichlorovinyl dimethylphosphate in human body fluids

Gas chromatographic procedures [GC with electron-capture detection (ECD) and GC-MS] for the quantitative analysis of metrifonate and its active metabolite 2,2-dichlorovinyl dimethylphosphate (DDVP) in human blood and urine were developed, validated, and applied to the analysis of clinical study samples. Analysis of metrifonate involved extraction of acidified blood with ethyl acetate followed by solid-phase clean-up of the organic extract. Acidified urine was extracted with dichloromethane and the residue of evaporated organic phase was reconstituted in toluene. ECD and diethyl analogue of metrifonate internal standard (I.S.) were used for quantitation of metrifonate. The metrifonate lower limit of quantitation (LOQ) was 10.0 microg/l. The DDVP metabolite was chromatographed separately after cyclohexane extraction of acidified blood and urine using d6-DDVP I.S. and MS detection. The LOQ of DDVP was 1 microg/l. Stability studies have confirmed that the matrix should be acidified prior to storage at -20 degrees C or -80 degrees C to inhibit chemical and enzymatic degradation of the analytes and to avoid overestimation of DDVP concentrations. Metrifonate was found to be stable in acidified human blood after 20 months of storage at -20 degrees C and after 23 months of storage at -80 degrees C. Under these conditions DDVP was found to be stable after 12 months of storage. Both assay procedures were cross-validated by different world-wide laboratories and found to be accurate and robust during analyses of clinical study samples.

Determination of metrifonate enantiomers in blood and brain samples using liquid chromatography on a chiral stationary phase coupled to tandem mass spectrometry

A novel enantioselective assay is described for the simultaneous determination of the metrifonate enantiomers BAY z 7216 and BAY z 7217 in extracts of whole blood samples obtained from rats, mice, rabbits and Beagle dogs as well as in rat brain tissue using liquid chromatography tandem mass spectrometry (LC/MS/MS) with thermally and pneumatically assisted electrospray ionization (TurboIonSpray(R)). Chromatographic separation is achieved on a chiral normal phase column with a mobile phase containing 0.25% water only. The total run time per sample is 11.0 min giving chromatographic base line separation of the enantiomers. Compared with previous methods this assay offers a higher sample throughput, excellent ruggedness and higher sensitivity. The limits of quantification for each enantiomer are 5.00 microg/L from 0.5 mL whole blood and 7.50 ng/g (ppb) using 0.333 g brain tissue, respectively. Similar assay specifications have been derived for the two enantiomers. The method has been validated for the analysis of blood samples from low and high dosed preclinical pharmacokinetic and toxicokinetic studies, corresponding to two analytical working ranges like e.g. 5.00 to 1000 microg/L and 200 to 40000 microg/L (0. 200 to 40.0 mg/L). For rat brain tissue the validated concentration range is 7.50 to 750 ng/g (ppb).

Comparison of turbulent-flow chromatography with automated solid-phase extraction in 96-well plates and liquid-liquid extraction used as plasma sample preparation techniques for liquid chromatography-tandem mass spectrometry

Turbulent flow chromatography (TFC) combined with the high selectivity and sensitivity of tandem mass spectrometry (MS-MS) is a new technique for the fast direct analysis of drugs from crude plasma. TFC in the 96-well plate format reduces significantly the time required for sample clean-up in the laboratory. For example, for 100 samples the workload for a technician is reduced from about 8 h by a manual liquid-liquid extraction (LLE) assay to about 1 h in the case of TFC. Sample clean-up and analysis are performed on-line on the same column. Similar chromatographic performance and validation results were achieved using HTLC Turbo-C18 columns (Cohesive Technologies) and Oasis HLB extraction columns (Waters). One 96-well plate with 96 plasma samples is analyzed within 5.25 h, corresponding to 3.3 min per sample. Compared to this LLE and analysis of 96 samples takes about 16 h. Two structurally different and highly protein bound compounds, drug A and drug B, were analyzed under identical TFC conditions and the assays were fully validated for the application to toxicokinetics studies (compliant with Good Laboratory Practices-GLP). The limit of quantitation was 1.00 microg/l and the linear working range covered three orders of magnitude for both drugs. In the case of drug A the quality of analysis by TFC was similar to the reference LLE assay and slightly better than automated solid-phase extraction in 96-well plates. The accuracy was -3.1 to 6.7% and the precision was 3.1 to 6.8% in the case of drug A determined for dog plasma by TFC-MS-MS. For drug B the accuracy was -3.7 to 3.5% and the precision was 1.6 to 5.4% for rat plasma, which is even slightly better than what was achieved with the validated protein precipitation assay.

Characterization of sequence elements involved in p53 stability regulation reveals cell type dependence for p53 degradation

The growth suppressive properties of the tumor suppressor protein p53 are activated upon DNA damage. The activation of p53 is reflected in increased p53 levels which are, at least in part, the result of an extended half-life of the protein. Although this suggests that stabilization of p53 is an intrinsic feature of p53 activation, the mechanisms involved in p53 degradation and stabilization are poorly understood. Here we report on the identification of an internal deletion mutant of wild-type p53, termed delta62-96, which can be stably expressed in various cell lines. This deletion mutant has a turnover rate similar to wild-type p53 and its stability is upregulated by treatment with UV light. In cell lines that express endogenous mutant or no p53, however, delta62-96 appears to be stable, strongly indicating that these cell lines have lost the ability to degrade p53. Further characterization of delta62-96 by mutational analyses defines sequence and structural requirements for p53 degradation and indicates that none of the known p53 phosphorylation sites is essential with respect to p53 stability regulation upon UV-irradiation.

Identical variant TSG101 transcripts in soft tissue sarcomas and various non-neoplastic tissues

Inactivation of the TSG101 gene was recently shown to induce malignant transformation of NIH/3T3 fibroblasts. Abnormal TSG101 transcription profiles were observed in various human cancers, and large intragenic deletions of the TSG101 gene were reported for a series of human breast cancer specimens, pointing to a potential tumor-suppressive activity of TSG101. However, subsequent more detailed studies on a large panel of breast carcinoma samples did not confirm the tumor-associated genomic deletions. Here we analyzed the transcription patterns of the TSG101 gene in soft-tissue sarcomas and non-neoplastic human tissues. Forty-five of 71 soft tissue sarcoma samples (63%) displayed variant transcripts; however, identical aberrant transcripts were also detected in seven of 15 non-neoplastic control tissues. Restriction fragment length polymorphism analysis of the TSG101 gene excluded major genomic rearrangements in the soft tissue sarcoma samples. Northern blot analysis revealed a very low abundance of variant transcripts as compared with the wild-type TSG101 transcript. These data point to aberrant splicing of the TSG101 mRNA in normal and transformed human mesenchymal tissues rather than tumor specific alterations of the TSG101 gene. In summary, this analyses does not support a pathogenic role for altered TSG101 expression in human soft tissue sarcomas.

Detection of SYT-SSX1/2 fusion transcripts by reverse transcriptase-polymerase chain reaction (RT-PCR) is a valuable diagnostic tool in synovial sarcoma

Cytogenetically, most synovial sarcomas are characterised by a specific chromosomal translocation [(X;18) (p11.2;q11.2)], which results in the generation of fusion transcripts comprising SYT (18q11) and either SSX1 or SSX2 (Xp11) sequences. By using a sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) protocol, specific SYT-SSX1/2 fusion transcripts were detected in 10 histopathologically confirmed synovial sarcomas. Control tumours with morphological spindle cell patterns mimicking monophasic synovial sarcoma tested negative (18/19) in the RT-PCR protocol, with the exception of one spindle cell sarcoma originally classified as a fibrosarcoma. Furthermore, the established RT-PCR protocol was used to evaluate the feasibility of SYT-SSX1/2 fusion transcript detection for minimal residual disease analysis. Analyses of surgical margins revealed a fusion transcript in two of four operations for synovial sarcoma analysed, one of which was diagnosed with tumour free margins by conventional histopathology. These data suggest that the RT-PCR amplification of SYT-SSX1/2 fusion transcripts is a valuable tool in the differentiation of synovial sarcomas, especially in cases of equivocal morphology. Additionally, the RT-PCR approach may be used for the detection of residual tumour cells in synovial sarcoma patients.

DNA ligase IV is essential for V(D)J recombination and DNA double-strand break repair in human precursor lymphocytes

Nonhomologous DNA end joining (NHEJ) is the major pathway for repairing double-strand DNA breaks. V(D)J recombination is a double-strand DNA breakage and rejoining process that relies on NHEJ for the joining steps. Here we show that the targeted disruption of both DNA ligase IV alleles in a human pre-B cell line renders the cells sensitive to ionizing radiation and ablates V(D)J recombination. This phenotype can only be reversed by complementation with DNA ligase IV but not by expression of either of the remaining two ligases, DNA ligase I or III. Hence, DNA ligase IV is the activity responsible for the ligation step in NHEJ and in V(D)J recombination.

Requirement for an interaction of XRCC4 with DNA ligase IV for wild-type V(D)J recombination and DNA double-strand break repair in vivo

The XRCC4 gene is required for the repair of DNA double-strand breaks in mammalian cells. Without XRCC4, cells are hypersensitive to ionizing radiation and deficient for V(D)J recombination. It has been demonstrated that XRCC4 binds and stimulates DNA ligase IV, which has led to the hypothesis that DNA ligase IV is essential for both of these processes. In this study deletion mutants of XRCC4 were tested for their ability to associate with DNA ligase IV in vitro and for their ability to reconstitute XRCC4-deficient cells in vivo. We find that a central region of XRCC4 from amino acids 100-250 is necessary for DNA ligase IV binding and that deletions within this region functionally inactivates XRCC4. Deletions within the C-terminal 84 amino acids neither affect DNA ligase IV binding nor the in vivo function of XRCC4. The correlation between the ability or inability of XRCC4 to bind DNA ligase IV and its ability or failure to reconstitute wild-type DNA repair in vivo, respectively, demonstrates for the first time that the physical interaction with DNA ligase IV is crucial for the in vivo function of XRCC4. Deletions within the N-terminal 100 amino acids inactivate XRCC4 in vivo but leave DNA ligase IV binding unaffected. This indicates further DNA ligase IV-independent functions of XRCC4.

DNA ligase IV binds to XRCC4 via a motif located between rather than within its BRCT domains

The covalent rejoining of DNA ends at single-stranded or double-stranded DNA breaks is catalyzed by DNA ligases. Four DNA ligase activities (I-IV) have been identified in mammalian cells [1]. It has recently been demonstrated that DNA ligase IV interacts with and is catalytically stimulated by the XRCC4 protein [2,3], which is essential for DNA double-strand break repair and the genomic rearrangement process of V(D)J recombination [4]. Together with the finding that the yeast DNA ligase IV homologue is essential for nonhomologous DNA end joining [5-7], this has led to the hypothesis that mammalian DNA ligase IV catalyzes ligation steps in both of these processes [8]. DNA ligase IV is characterized by a unique carboxy-terminal tail comprising two BRCT (BRCA1 carboxyl terminus) domains. BRCT domains were initially identified in the breast cancer susceptibility protein BRCA1 [9], but are also found in other DNA repair proteins [10]. It has been suggested that DNA ligase IV associates with XRCC4 via its tandem BRCT domains and that this may be a general model for protein-protein interactions between DNA repair proteins [3]. We have performed a detailed deletional analysis of DNA ligase IV to define its XRCC4-binding domain and to characterize regions essential for its catalytic activity. We find that a region in the carboxy-terminal tail of DNA ligase IV located between rather than within BRCT domains is necessary and sufficient to confer binding to XRCC4. The catalytic activity of DNA ligase IV is affected by mutations within the first two-thirds of the protein including a 67 amino-acid amino-terminal region that was previously thought not to be present in human DNA ligase IV [11].

Heat pain increases the perceived magnitude of an innocuous electrical stimulus: evidence for a peripheral mechanism

Painful heat produced an increase in the perceived magnitude of an innocuous electrical stimulus applied either to the sural nerve or to the skin of the dorsum of the foot. The increased sensitivity was observed when the painful heat was spatially coincident with the electrical stimulus, and when it was not coincident but adjacent within the same dermatome. Painful heat had no effect when it was applied to the contralateral foot, which makes it unlikely that attention or arousal played any role in the increased electrical sensitivity produced by ipsilateral heat. The painful heat also produced an increase in the amplitude of the sural nerve compound action potential (CAP). The heat-pain-related changes in the CAP and subjective magnitude ratings were in the same direction, which suggests that the latter were due at least in part to a temperature-dependent change in the electrical sensitivity of the peripheral afferents.

Temperature tolerance of hydrogenase expression in Alcaligenes eutrophus is conferred by a single amino acid exchange in the transcriptional activator HoxA

Expression of the soluble (SH) and membrane-bound (MBH) hydrogenases in the facultatively lithoautotrophic bacterium Alcaligenes eutrophus is dependent on the transcriptional activator HoxA and the alternative sigma factor sigma 54. Deletion analysis revealed that a region 170 bp upstream of the transcriptional start of the SH operon is necessary for high-level promoter activity. Mobility shift assays with DNA fragments containing the SH upstream region and purified beta-galactosidase-HoxA fusion protein isolated from Escherichia coli or authentic HoxA isolated by immunoaffinity chromatography from A. eutrophus failed to detect specific binding. In contrast, A. eutrophus extracts enriched for HoxA by heparin-Sepharose chromatography and ammonium sulfate fractionation produced a weak but discrete shift in the mobility of the target DNA. This effect was not observed with comparable extracts prepared from hoxA mutants. A similar experiment using antibodies against HoxA confirmed that HoxA was responsible for the observed mobility shift. Extracts prepared from a temperature-tolerant mutant of A. eutrophus gave a stronger retardation than did those from the wild type. Unlike the wild type, the hox(Tr) mutant is able to grow with hydrogen at temperatures above 33 degrees C because of a mutation in the regulatory gene hoxA. In this paper, we show that a single amino acid substitution (Gly-468-->Val) in the C-terminal part of HoxA is responsible for temperature tolerance. The SH upstream region also contains sequence motifs resembling the E. coli integration host factor (IHF) binding site, and purified E. coli IHF protein shifted the corresponding indicator fragment.

Enantioselective assay for the determination of nisoldipine in dog, rat and mouse plasma by chiral microbore high-performance liquid chromatography combined with gas chromatography-mass spectrometry

A sensitive, selective and validated method for the enantioselective determination of (+)- and (-)-nisoldipine in rat, mouse and dog plasma following administration of nisoldipine racemate is described. The alkalized plasma samples containing [13C4]nisoldipine racemate as internal standard (ISTD) were extracted once with toluene. The enantiomers of nisoldipine were quantitatively separated by high-performance liquid chromatography on a 250 x 2 mm I.D. column containing tris(4-methylbenzoate)-modified cellulose on silica. The fractions containing either the (+) or (-)-enantiomer of the analyte and [13C4]ISTD were analysed by gas chromatography with mass-selective detection in the single-ion monitoring mode. The limits of determination and detection were 0.5 and 0.2 ng/ml, respectively, the total precision was better than 7% (R.S.D. at 5 and 50 ng/ml, n = 35) and the accuracy was better than 10% (0.5-100 ng/ml, n = 23). The sum of the concentrations of the enantiomers determined with this assay corresponds to the concentration of the racemate determined independently by capillary gas chromatography with electron-capture detection (accuracy better than 15%, 1-80 ng/ml). The method was used for the analysis of more than 500 plasma samples obtained from toxicokinetic studies.

The mouse bone marrow micronucleus test: evaluation of 21 drug candidates

The mouse bone-marrow micronucleus test is one of the most widely used genetic toxicology assays. In this report the results of testing 21 compounds in the micronucleus test are presented. Of the 21 compounds tested, 3 potential chemotherapeutic agents were identified as strongly clastogenic. In addition, one compound was identified as a weak inducer of micronuclei in the assay. Further testing of this compound in an in vivo bone marrow metaphase analysis failed to confirm this material as clastogenic. The remaining 17 compounds were classified as negative in the assay. In general the results of the micronucleus test agreed with the results of other genetic toxicology assays on this group of compounds.

Identifying catastrophic psychiatric cases. Targeting managed-care strategies

Case management programs, a specialized form of utilization review (UR), focus their interventions on catastrophic cases, which comprise the minority of patients while accounting for the majority of costs. Many case management programs base their case identification and review criteria on diagnosis alone, although research has shown that it is a poor predictor of length of stay. Using claims data from a large nationwide insurer, the authors developed an empirical approach to identifying potentially catastrophic cases. The findings suggest that, in addition to diagnosis, other factors such as age and treatment setting contribute to long stays and high costs and thus should be used to identify catastrophic cases for case management interventions. Strategies to target case management programs must be considered not only in light of their impact on cost but on the quality of care for individual patients.

Interaction patterns and communication skills in sexually distressed, maritally distressed, and normal couples: two experimental studies

Two experiments are reported evaluating the behavioral deficits in communication skills found in couples with secondary sexual dysfunction (primarily of the female partner). Groups of satisfied couples and couples experiencing primarily marital distress served as controls. In Experiment 1 which analyzed the most frequently chosen behavioral reactions to 22 situations in a questionnaire (KIP), sex clients and maritally distressed couples were distinguished from the normal control group. In Experiment 2, videotaped conflict discussions were analyzed. Results show that clients with sexual dysfunctions, especially a subgroup with high scores on depressed mood, have even worse ratings on influence strategies, self-acceptance, and nonverbal expression than both maritally distressed and normal couples. Implications for theory and especially for setting treatment goals and selecting treatment interventions are discussed.

Sexual fantasies of sexually distressed and nondistressed men and women: an empirical comparison

Sexual fantasies are seen as an important source of information and a modality for treatment procedures in sex therapy programs. While drive-reduction models view fantasy as a symptom of a deficiency state, cognitive-behavioral approaches take fantasies as an index of a satisfying sex life. While current data tend to support the behavioral position, no systematic comparison has been undertaken of men and women with and without sexual distress. This study compared written examples of sexual daydreaming, masturbatory and coital fantasies as well as habitual patterns of employing fantasies during sexual activities of the above mentioned groups. Other psychotherapy clients served as control. Sex differences were sparse and the comparison between distressed and nondistressed tended to support the behavioral position. Although sexual fantasizing is positively related to a satisfying sex life, fantasies are often used for reducing aversive emotions. Subjects older than 35 years showed fewer fantasies and lower correlations between daydreaming and sexual activity.

Bacterial mutagenicity and mammalian cell DNA damage by several substituted anilines

Several substituted alkyl- and haloanilines were tested for their ability to mutate Salmonella typhimurium and to damage the DNA of mammalian (V79) cells. These results were correlated with their reported carcinogenicity. Of 9 suspected carcinogens, 4 were bacterial mutagens and 4 (out of 7 tested) damaged DNA of V79 cells. The following compounds were weakly mutagenic (less than 150 revertants/mumole): 4-fluoroaniline, 2,3-, 2,4-, 2,5- and 3,4-dimethylaniline, and 2-methyl-4-fluoroaniline. The following compounds were strong mutagens: 2,4,5-trimethylaniline, 2-methyl-4-chloro-, and 2-methyl-4-bromo-, 4-methyl-2-chloro-, 4-methyl-2-bromo- and 2-ethyl-4-chloroaniline. The compounds which damaged DNA in V79 cells were: 2 methyl-4-chloroaniline, 2-methyl-4-bromoaniline, 2,4,5- and 2,4,6-trimethylaniline.

[Sociopsychiatric treatment combination in patients who are partly inpatients and genuine outpatients: definition and comparison (author's transl)]

The article gives a definition and brief description of those possibilities of treatment which are important in the sociopsychiatric therapy of psychoses: sociotherapy, therapy with neuroleptics, and psychotherapy as such, as well as their various combinations. Basing on a representative random trial from the fields of outpatient and nightpatient wards, the distribution of therapeutic potential among these combinations is described and outlined in a manner customary for the work bone by the Zürich Sociopsychiatric Service. It is evident, despite the fact that the work performed at our hospital is basically of the psychotherapeutic nature, patients can be rehabilitated with a lower level of neuroleptics provided sufficient sociotherapeutic measures are offered, including satisfactory psychotherapeutic efforts--the chances of meeting these demands being greater in our night ward. Patients who cannot be fully rehabilitated but more or less integrated, did not show such obvious differences, whereas the more intense sociotherapeutic programme of the nigth ward enabled the reintegration even of the nigth ward enabled the reintegration even of more seriously disturbed patients than could be achieved by mere outpatient follow-up treatment.

[Comparison of altered states of consciousness induced by the hallucinogens (--)-delta9-trans-tetrahydrocannabinol (delta9-THC) and N,N-dimethyltryptamine (DMT) (author's transl)]

The study compares altered states of consciousness induced by the hallucinogens (--)delta9-trans-Tetrahydrocannabinol (delta9-THC) and N,N-Dimethyltryptamine (DMT) using two placebo control groups. A total of 24 subjects received 250 mug delta9-THC p.o./kg body weight and 26 subjects were treated with 250 mug DMT i.m./kg. Placebo was given to 24 subjects. The effects were assessed by a questionnaire administered following the experimental conditions. Questionnaire items were combined into the following eight scales according to their content and several cirteria of the theory of mental testing: visual hallucinations (illusions), auditory hallucinations (illusions), impairment of memory and attention, depersonalization syndrome, deprealization syndrome, changes of body image, euphoric state and anxious-depressive state. The two hallucinogen groups differed significantly from placebo on all eight scales. No difference, however, between delta9-THC and DMT was significant. On the scale "optical hallucinations (illusions)" a tendency that DMT might have stronger effects than delta9-THC was found. Methodological problems of comparing different hallucinogens are discussed.

[Effects of (--)delta-9-trans-tetrahydrocannabinol (delta-9-THC) on tests of psychoticism. A study of Eysenck's drug postulate on the effects of hallucinogens in relation to psychoticism (author's transl)]

In a double-blind study on 36 volunteers the effects of 250 mug/kg (--)delta-9-trans-tetrahydrocannabinol p.o. on objective and performance tests measuring psychoticism according to Eysenck were assessed. The hypothesis was tested that subjects treated with delta-9-THC differ from those receiving placebo in the same way as endogenous psychotics differ from normals. Confirmation was obtained in only 5 out of 19 variables. Four of these 5 variables may be considered as tests of concentration.