Recommendations for the diagnosis and management of vaccine-induced immune thrombotic thrombocytopenia

There have recently been safety concerns regarding an increased risk of vaccine-induced immune thrombotic thrombocytopenia (VITT) following administration of SARS-CoV-2 adenoviral vector vaccines. The Southern African Society of Thrombosis and Haemostasis reviewed the emerging literature on this idiosyncratic complication. A draft document was produced and revised by consensus agreement by a panel of professionals from various specialties. The recommendations were adjudicated by independent international experts to avoid local bias. We present concise, practical guidelines for the clinical management of VITT.

The barriers of workplace safety and health management: from the supervisor’s perspective

Background

Previous researches demonstrated that workplace safety and health (WSH) management plays a major role in promoting worker’s health and well-being. However, organizational factors hinder promoting WSH management program. The main aim of this study is to explore the probable existence of barrier from WSH supervisor’s perspective.

Methods

This study employed a qualitative design to gain an in-depth and holistic understanding of WSH from the supervisor’s perspective. Eight focus groups were conducted in Taiwan. A total of 81 supervisors (employer, human resource section, environmental safety section) from the manufacturing industry, construction industry, and service industry participated in this study. All interview contents were transcribed and coded. Matrices were constructed to identify themes and evolving concepts.

Results

Three main barriers were identified1. Lacking of top management commitment and support (e.g., top management focused more on employees’ work performance than their safety and health, top management commitment was just a declaration but with no action, and top management only conducted the traditional occupational hazards control to fit the minimum standards of national policy, and ignored employees’ mental health and well-being); 2.Lacking of employee’s safety awareness (e.g., employee lacked the motivation to attend training program; 3.Organizational resources were not enough to implement occupational safety and health management (e.g., the supervisor lacked professional skills in promoting WSH program).

Conclusions

The study findings provide an integrated basis for practical application and further research. The workplace supervisor should be trained the professional skills in workplace safety and health management. Then, the workplace psychosocial safety climate can be built while top management and employee have higher workplace safety and health awareness.

Key messages

This study contributes to occupational health research from the supervisor’s perspective. This study also hints at the potential role of top management promoting employee’s health and well-being.

How do long-term development and periodical changes of river-floodplain systems affect the fate of contaminants? Results from European rivers

In many densely populated areas, riverine floodplains have been strongly impacted and degraded by river channelization and flood protection dikes. Floodplains act as buffers for flood water and as filters for nutrients and pollutants carried with river water and sediment from upstream source areas. Based on results of the EU-funded "AquaTerra" project (2004-2009), we analyze changes in the dynamics of European river-floodplain systems over different temporal scales and assess their effects on contaminant behaviour and ecosystem functioning. We find that human-induced changes in the hydrologic regime of rivers have direct and severe consequences on nutrient cycling and contaminant retention in adjacent floodplains. We point out the complex interactions of contaminants with nutrient availability and other physico-chemical characteristics (pH, organic matter) in determining ecotoxicity and habitat quality, and draw conclusions for improved floodplain management.

Helicobacter pylori-independent MALT lymphoma patients responsive to thalidomide—the molecular mechanism and the clinical application

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Background: We have recently demonstrated that nuclear expression of BCL10 or NF-κB helps predict H. pylori-independent status; and inflammatory cytokines such as TNF-α may be related to BCL10 nuclear translocation (Blood 2005;106:1037–41;J Biol Chem 2006;281:167–75). Recent studies have been shown that the chimeric protein of t(11;18)(q21;q21) can lead to constitutive NF-κB activity and thereby mediate cell survival and anti-apoptotic signals. The present study was conducted to investigate the molecular mechanism and the clinical efficacy of thalidomide, an TNF-α or NF-κB inhibitor, in H. pylori-independent MALT lymphoma. Methods: Between October 2003 and June 2007, our study enrolled 11 H. pylori-independent MALT lymphoma patients ( 7 men and 4 women; age range, 43 to 79 years; 7 patients who had failed chemotherapy or rituximab) with nuclear expression of BCL10 or NF-κB in pretreatment lymphoma tissues treated at National Taiwan University Hospital with thalidomide 100mg to 200 mg oral given daily. The presence of t(11;18)(q21;q21) was identified by a multiplex reverse transcriptase polymerase chain reaction of the API2-MALT1 chimeric transcript. Results: Three (27.3%) of 11 patients achieved a complete response (CR), and 3 (27.3) of 11 patients achieved a partial response (PR), resulting in an overall response rate of 54.5% (95% CI, 19.5%-89.6%). The median time from thalidomide therapy to CR was 3.0 months (range, 2.7–4.9 months). At a median follow-up of 41.6 months (range, 17.7–63.8 months), the 3-year event-free survival and overall survival after thalidomide treatment was 80.8%, and 88.9%, respectively. The API2-MALT1 fusion transcript for t(11;18)(q21;q21) was detected in 1 (16.7%) of 6 patients with CR or PR, and 4 (80.0%) of 5 patients with stable or progressive disease (P = 0.08). Conclusions: Our results indicate that thalidomide can be an adjuvant treatment for H. pylori-independent MALT lymphoma patients. Additional investigation of the molecular mechanisms and biologic significance of the API2-MALT1 fusion transcript responsible for thalidomide resistance in this group of tumors is needed.

No significant financial relationships to disclose.

Seasonal variation of sediment toxicity in the Rivers Dommel and Elbe

Contaminated sediment in the river basin has become a source of pollution with increasing importance to the aquatic ecosystem downstream. To monitor the temporal changes of the sediment bound contaminants in the River Elbe and the River Dommel monthly toxicity tests were applied to layered sediment and river water samples over the course of 10 months. There is an indication that contaminated sediments upstream adversely affected sediments downstream, but this process did not cause a continuous increase of sediment toxicity. A clear decrease of toxic effects in water and upper layer sediment was observed at the River Elbe station in spring related to high water discharge and algal blooms. The less obvious variation of sediment toxicity in the River Dommel could be explained by stable hydrological conditions. Future monitoring programmes should promote a more frequent and intensive sampling regime during these particular events for ecotoxicological evaluation.

Electromagnetically induced magnetochiral anisotropy in a resonant medium

Chirality has been extensively studied for well over a century, and its potential applications range from optics to chemistry, medicine, and biology. Ingenious experiments have been designed to measure this naturally small effect. Here we discuss the possibility of producing a medium having a large chiral effect by using the ideas of coherent control. The coherent fields resonant with appropriate transitions in atomic or molecular systems can be used to manipulate the optical properties of a medium. We demonstrate experimentally very large magnetochiral anisotropy by using electromagnetic fields in atomic Rb vapors.

Basic fibroblast growth factor and fibroblast growth factor receptors in adult olfactory epithelium

Basic fibroblast growth factor (FGF2) stimulates proliferation of the globose basal cells, the neuronal precursor in the olfactory epithelium. The present study investigates the expression of basic fibroblast growth factor and fibroblast growth factor receptors in the adult olfactory epithelium. FGF2 immunoreactivity was expressed widely in the olfactory epithelium, with the highest density of immunoreactivity in the supporting cells. In contrast, most cells in the epithelium expressed FGF2 mRNA. Fibroblast growth factor receptor-1 (FGFr1) immunoreactivity was densest in the basal cell and neuronal layers of the olfactory epithelium and on the apical surface of supporting cells. In the lamina propria FGF2 immunoreactivity and mRNA were densest in cells close to the olfactory nerve bundles. FGFr1 immunoreactivity was heaviest on the olfactory ensheathing cells. Using reverse transcriptase-polymerase chain reaction analysis, the olfactory epithelium was shown to express only three receptor splice variants, including one (FGFr1c) with which basic fibroblast growth factor has high affinity. Other receptor splice variants were present in the lamina propria. Taken together, these observations indicate endogenous sources of FGF2 within the olfactory epithelium and lamina propria and suggest autocrine and paracrine pathways via which FGF2 might regulate olfactory neurogenesis. The observation of only three receptor splice variants in the olfactory epithelium limits the members of the fibroblast growth factor family which could act in the olfactory epithelium. The widespread distribution of receptors suggests that fibroblast growth factors may have roles other than proliferation of globose basal cells.

A computer-aided design mammography screening system for detection and classification of microcalcifications

This paper presents a prototype of a computer-aided design (CAD) diagnostic system for mammography screening to automatically detect and classify microcalcifications (MCCs) in mammograms. It comprises four modules. The first module, called the Mammogram Preprocessing Module, inputs and digitizes mammograms into 8-bit images of size 2048x2048, extracts the breast region from the background, enhances the extracted breast and stores the processed mammograms in a data base. Since only clustered MCCs are of interest in providing a sign of breast cancer, the second module, called the MCCs Finder Module, finds and locates suspicious areas of clustered MCCs, called regions of interest (ROIs). The third module, called the MCCs Detection Module, is a real time computer automated MCCs detection system that takes as inputs the ROIs provided by the MCCs Finder Module. It uses two different window sizes to automatically extract the microcalcifications from the ROIs. It begins with a large window of size 64x64 to quickly screen mammograms to find large calcified areas, this is followed by a smaller window of size 8x8 to extract tiny, isolated microcalcifications. Finally, the fourth module, called the MCCs Classification Module, classifies the detected clustered microcalcifications into five categories according to BI-RADS (Breast Imaging Reporting and Data System) format recommended by the American College of Radiology. One advantage of the designed system is that each module is a separate component that can be individually upgraded to improve the whole system. Despite that it is still is a prototype system a preliminary clinical evaluation at TaiChung Veterans General Hospital (TCVGH) has shown that the system is very flexible and can be integrated with the existing Picture Archiving and Communications System (PACS) currently implemented in the Department of Radiology at TCVGH.

Latino physician supply in California: sources, locations, and projections

PURPOSE

To determine the number of Latino physicians in California, identify the schools and countries where they were educated, determine the percentage located in Latino areas, and project the supply of Latino physicians to 2020.

METHOD

From a 1999 list of 74,345 licensed physicians, the authors identified Latino U.S. medical graduates (USMGs) by "heavily Hispanic" surnames and Latino international medical graduates (IMGs) by country and school of graduation. The 1999 license addresses of all physicians in Los Angeles County were analyzed against 1998 Latino-population data by zip code. A baseline projection of the supply of Latino physicians was based on the ten-year (1986 to 1995) average annual production of Latino physicians educated in California, out of state, and in Latin America. A worst-case projection assumed the continuation of recent trends: a 32% decrease in California-educated Latino USMGs, a 19% decrease in out-of-state Latino USMGs, and a reduction of Latino IMGs to five per year.

RESULTS

In 1999, 3,578 Latino physicians comprised 4.8% of all Californian physicians. In contrast, Latinos made up 30.4% of the state's population. Latino physicians were more likely than non-Latinos to have addresses in a heavily Latino zip code. In the baseline projection, while the overall supply of Latino physicians will increase by nearly 30% by 2020, that growth will be dwarfed by the 74% growth in the Latino population over the same time. In the worst-case projection, the actual number of Latino physicians will decrease from the 1999 figure of 3,578 to 3,448 by 2020, while the Latino population continues to grow.

CONCLUSIONS

(1) The Latino USMG supply must be markedly increased in the number of first-year matriculants in both California and out-of-state schools. (2) The issue of Latino IMGs requires special attention, and may provide a temporary solution to the Latino physician shortfall. (3) Non-Latino physicians need to be prepared to be culturally effective with a large and growing Latino patient population.

HIV-1 genotypic resistance patterns predict response to saquinavir-ritonavir therapy in patients in whom previous protease inhibitor therapy had failed

BACKGROUND

Tests for resistance to HIV drugs are available for clinical use; however, their predictive value has not been fully assessed.

OBJECTIVES

To determine HIV-1 genotypic predictors of a virologic response to saquinavir-ritonavir therapy in patients in whom at least one previous protease inhibitor-containing regimen had failed and to compare the predictive value of baseline genotype with that of standard clinical evaluation.

DESIGN

Retrospective clinical cohort study.

SETTING

University-based HIV clinic.

PATIENTS

54 HIV-1-infected adults treated with saquinavir-ritonavir who had experienced virologic failure while receiving a protease inhibitor-containing regimen for at least 3 months.

MEASUREMENTS

HIV-1 reverse transcriptase and protease gene sequences, CD4 cell counts, clinical characteristics, detailed antiretroviral treatment history, and plasma HIV-1 RNA levels at baseline and at three follow-up time points (median, 4, 12, and 26 weeks). Virologic failure was defined as a plasma HIV RNA level greater than 1000 copies/mL.

RESULTS

In 22 patients (41%), a plasma HIV-1 RNA level less than 500 copies/mL was achieved by week 12; in 15 patients (28%), this response was maintained through week 26. Clinical characteristics predicting a poorer response included a diagnosis of AIDS, lower CD4 cell count, and higher plasma HIV RNA level (P<0.03). Number of previous nucleoside reverse transcriptase inhibitors, previous protease inhibitor therapy, and duration of previous protease inhibitor therapy were predictors of poorer response (P<0.01). Multivariate regression models revealed that protease mutations present at the initiation of saquinavir-ritonavir therapy were the strongest predictors of virologic response. A model of clinical features explained up to 45% of the variation in virologic outcomes by week 12, whereas the explained variance was 71% when genotypic predictors were included.

CONCLUSIONS

In patients in whom protease inhibitor-containing antiretroviral therapy fails, HIV-1 genotype is predictive of virologic response to subsequent therapy. This predictive capacity adds to that of standard clinical evaluation.

Identification of biased amino acid substitution patterns in human immunodeficiency virus type 1 isolates from patients treated with protease inhibitors

Human immunodeficiency virus type 1 (HIV-1) amino acid substitutions observed during antiretroviral drug therapy may be caused by drug selection, non-drug-related evolution, or sampling error introduced by the sequencing process. We analyzed HIV-1 sequences from 371 untreated patients and from 178 patients receiving a single protease inhibitor. Amino acid substitution patterns during treatment were compared with inferred substitution patterns arising evolutionarily without treatment. Our results suggest that most treatment-associated amino acid substitutions are caused by selective drug pressure, including substitutions not previously associated with drug resistance.

Reproducibility of LSI HER-2/neu SpectrumOrange and CEP 17 SpectrumGreen Dual Color deoxyribonucleic acid probe kit. For enumeration of gene amplification in paraffin-embedded specimens: a multicenter clinical validation study

Overexpression and/or amplification of HER-2/neu gene have been found to be prognostic and predictive in breast and other cancers. Fluorescence in situ hybridization (FISH) assay, with its sensitivity and specificity, can be a superior method of detection when its performance characteristics are demonstrated. A multicenter study was initiated to evaluate the reproducibility of the LSI HER-2/neu SpectrumOrange and CEP 17 SpectrumGreen Dual Color DNA Probe for enumeration of both the HER-2/neu gene and chromosome 17 (signals) in interphase cells. Section slides were prepared from four cell lines (H, E, R, and N) with known ratios of the HER-2/neu to CEP 17 copy numbers (approximately H = 1.10, E = 1.70, R = 4.50, N = 9.0). The study variable was the ratios of the HER-2/neu to chromosome 17 copy numbers. Reproducibility with respect to assay, site, lot, day and reader was evaluated at 3 centers. Out of 120 specimen slides, 100 percent were successfully assayed. There were no significant differences among: (1) four repeated assays of the same specimen (p = 0.99), (2) the four probe lots (p = 0.33), or (3) the four study days (p = 0.54). There was statistically significant, but not important differences among centers and between readers. The ratios of the HER-2/neu to chromosome 17 copy numbers were estimated with accuracy and precision; the mean ratios (and sd) for specimens, H, E, R, and N were 1.05 (0.06), 1.81 (0.12), 4.48 (0.28), and 8.60 (1.23), respectively. In summary, assays with the LSI HER-2/neu and CEP 17 Dual Color DNA Probe Kit, conducted at three sites by 6 different technicians, over 8 assay days, using kits from four lots, were performed with a high success rate in paraffin-embedded specimens. The signal enumeration was also accurate and precise. This study demonstrated that the results obtained by using the LSI HER-2/neu SpectrumOrange and CEP 17 SpectrumGreen Dual Color DNA Probe Kit are reliable and reproducible.

Timing of the expression of enamel gene products during mouse tooth development

In order to understand the mechanisms involved in tooth development it is important to define the timing for tissue-specific gene expression. A consequence of ameloblast cell differentiation is the sequential expression of tissue-specific genes whose products form the enamel extracellular matrix. The ameloblast phenotype has been characterized as consisting of two major classes of proteins: amelogenins and non-amelogenin proteins such as anionic enamel proteins (enamelins, tuft proteins, tuftelin, sulfated proteins) and enamel proteases. The postulated functions for the anionic enamel proteins are as nucleators for hydroxyapatite crystal formation while amelogenins control the crystal size, growth and orientation. While the amelogenins have been well characterized, detailed knowledge for anionic enamel proteins has been sparse. In the present study, we designed experiments to characterize one of the anionic enamel proteins from mouse molars, tuftelin, and to determine the timing of expression of this protein during molar tooth development. Our results showed the initial detection of tuftelin transcripts within proliferating inner enamel epithelial cells at very early stages of tooth development (13 days of embryonic development equivalent to the bud stage of tooth development). These data provide direct evidence that invalidates previous dogmas that enamel proteins were synthesized by polarized, non-dividing, fully differentiated ameloblast cells. In addition, tuftelin was found to be synthesized also by dental papilla mesenchyme cells suggesting that this protein is not enamel-specific. These data taken together open the possibility that the tuftelin present in the dentino-enamel junction could be secreted by both, preodontoblast cells and preameloblast cells. It might also suggest a possible different role for tuftelin than nucleator of hydroxyapatite crystals.

Age dependence of cerebrovascular response mechanisms in domestic pigs

Hypercapnia-induced cerebral vasodilation in the newborn pig is a prostanoid-associated response. In some adult models, hypercapnic cerebral vasodilation is associated with the generation of nitric oxide (NO). Acetylcholine (ACh) produces a NO-dependent cerebral vasodilation in many adult models, but topical ACh is a prostanoid-associated cerebral vasoconstrictor in the newborn pig. We hypothesized that mediators influencing cerebral response can be age dependent. Juvenile domestic pigs were compared with newborn pigs, and pial arteriolar diameters were measured by use of a closed cranial window during hypercapnia and topical ACh (10(-5) M). Four different conditions were explored: control, topical N omega-nitro-L-arginine (L-NNA, 10(-3) M), indomethacin (5 mg/kg i.v.), and both L-NNA and indomethacin. All animals were anesthetized with alpha-chloralose. As opposed to the complete block in the newborn, indomethacin only partially attenuated the hypercapnic cerebral vasodilation in the juvenile pig.L-NNA, which had no effect on the response of the newborn, produced a partial attenuation of the hypercapnic response of the juvenile. The combination of indomethacin and L-NNA blocked the response in both age groups. Topical ACh in both age groups initially produced cerebral vasoconstriction, but, in the juvenile, this was followed by a sustained cerebral vasodilation. Indomethacin blocked the early vasoconstriction in both age groups. L-NNA, which had no effect in the response of the newborn to ACh, blocked the vasodilation seen in the juvenile. The combination of both inhibitors blocked all response to ACh in the juvenile. These data indicate that although the cerebral vascular responses to ACh and hypercapnia are prostanoid associated and NO independent in the newborn pig, NO assumes an increasing role in dilatory responses with development.

Chief residency in PM&R. A balance of education and administration

The role of the Physical Medicine and Rehabilitation (PM&R) chief resident (CR) in physiatry residency education programs is the subject of annual deliberation in many academic centers. A national survey of PM&R programs was conducted to determine CR number, selection method, responsibilities, duration of service, and postresidency destiny. The questionnaire generated a response rate of 86% with 90% of programs reporting 1-3 CRs per year. A range of 1-11 CRs were selected annually per program. The most common methods of CR selection were faculty vote (45%), combined resident-faculty vote (22%), and other (33%). The prevalence of administrative responsibilities included orienting new residents (97%), formulating call schedules (92%), dispute mediation (88%), medical student-residency interviews (87%), rotation schedule configuration (64%), faculty meeting participation (61 %), social event promotion (59%), and elective and externship schedule development (31 %). Educational duties included teaching and organizing didactics (87%), organizing pharmaceutical and rehabilitation equipment inservices (77%), arranging didactics (77%), board review coordination (72%), arranging grand round speakers (66%), core curriculum lectures (61%), and facilitating resident research (37%). CR career goals included group practice (48%), academic faculty (29%), solo practice (5%), and fellowship (18%). Overall, PM&R CRs maintain considerable involvement in the educational aspects of residency training, although their clinical and administrative duties predominate. Although the PM&R CRs contribute significantly to the academic growth and development of their respective training programs, only a modest percentage (47%) of CRs choose to remain in academic physiatry via an attending (29%) or fellowship (18%) position.

pHi in piglet cerebral microvascular endothelial cells: recovery from an acid load

Cerebral microvascular endothelial cells form a barrier between the blood and brain, which is critical for normal neuronal functions. These endothelial cells can be challenged by metabolic and respiratory acidosis, especially in newborn babies. We investigated mechanism(s) by which cerebral endothelial cells recover intracellular pH (pHi) when challenged with an intracellular acid load. pHi in piglet cerebral microvascular endothelial cells in primary culture was monitored using the pH-sensitive fluorescent dye BCECF (2',7'-bis-2-carboxyethyl-5(6)-carboxy-fluorescein acetoxymethyl ester), with dual wavelength fluorescence spectroscopy. Endothelial cells attached to coverslips and continuously superfused with HCO3-/CO2 containing medium (25 mM HCO3-, 5% CO2; pH 7.40) have a steady state of pHi of 7.18 +/- 0.02. Under basal conditions, amiloride (100 microMol) and H2DIDS (0.5 mM) decreased pHi 0.12 +/- 0.01 and 0.05 +/- 0.01 pH units, respectively. Removal of external Na+ lowered pHi 0.18 +/- 0.02pH units, while Cl- free medium decreased pHi 0.16 +/- 0.03pH units. These data suggest the presence of an amiloride-sensitive Na+-H+ exchanger and a Na+-dependent HCO3- -Cl- anion exchanger in endothelial cells. Propionate and high PCO2 cause rapid intracellular acidification at constant pH. The cells recover to control pHi over 10 min. Recovery from propionate was largely inhibited by amiloride, slightly inhibited by H2DIDS, and completely prevented by the combination. pHi recovery during elevated PCO2 was blocked by amiloride, H2DIDS, or Na+-free media. These results indicate that recovery from intracellular acidosis can involve amiloride-sensitive Na+-H+ exchange and a Na+-dependent HCO3-/Cl- anion exchange. Relative contributions of pumps and their independence appears to depend on the nature of the acid load.

An "atomic" approach to dis/ability assessment

Disability assessment is a complex process that requires consideration of both work demands and clinical conditions. It is commonly practiced in two very distinct fashions. First, poorly specified processes are used to reach decisions about highly specific situations; second, broad generalizations are often applied, which may be poorly applicable to specific situations. A new approach allows the integration of these two methods. The "atomic" approach has two phases: "disaggregation" into the smallest possible meaningful knowledge units (atoms) and then "reintegration" (reassembly). Individual information units may be applicable to a wide variety of different situations, providing an efficient system. The atomic approach includes two tracks that merge to produce the dis/ability assessment: Clinical track (diagnosis-->confirmation test; diagnosis-->impact assessment test-->test result-->physiologic/anatomic limitation; and the job demand track (job-->task-->sub task-->functional work demand index-->empiric data). The approach describe offers advantages of rationality, empiric and face validity, and efficiency. The logic is fully explicable, and most information units (atoms) can be used in many ways to cover new situations. It is applicable to both individual case situations and to large-scale system development.

Identification of the site in the substance P (NK-1) receptor for modulation of peptide binding by sulfhydryl reagents

Substance P (SP) is a peptide neurotransmitter that is involved in multiple responses in both the central and the peripheral nervous systems through a G-protein-coupled contains a number of conserved cysteine residues. To localize and identify the cysteine residues that participate in receptor binding, intact Chinese hamster ovary cells expressing the SP receptor were treated with various sulfhydryl reagents and the effect of these reagents on radioiodinated SP binding affinity and dissociation rate was determined. We used a series of amphiphilic maleimide derivatives in which the reactive maleimide group penetrates to different depths within the plane of membrane. Only the maleimide derivatives with intermediate chain lengths modified receptor binding properties, indicating that the reactive sulfhydryl group is located within a transmembrane domain of the receptor close (within 1.7 nm) to the extracellular border. Since peptide binding to a mutant receptor C199S, in which Cys-199 was replaced by a serine, was found to be insensitive to modulation by sulfhydryl reagents, this reactive sulfhydryl group is on Cys-199 of the receptor. Receptor occupancy by SP protects Cys-199 from modification and thus this residue is either located at or conformationally linked to the SP binding site.

Genotypic analysis of primary head and neck squamous carcinoma by combined fluorescence in situ hybridization and DNA flow cytometry

Concurrent DNA flow cytometric (FCM) and fluorescence in situ hybridization (FISH) analyses were prospectively performed on 24 primary untreated head and neck squamous carcinomas for characterization of the genotypic and phenotypic DNA aberrations of these neoplasms. Eleven tumors (42.0%) manifested DNA diploidy (DI = 1.00) and 15 (58.0%) had DNA aneuploidy (DI < or > 1.00) by FCM. Fluorescence in situ hybridization results showed aneusomy in the majority of DNA diploid and in all DNA aneuploid tumors. The extent of the abnormalities for individual chromosomes and the number of involved chromosomes in a given DNA diploid or aneuploid tumor were significantly different. Overall, a statistical correlation between the FCM DNA index (DI) and the magnitude of the chromosomal aberration by FISH was found. Our results also show a significant association between the DI and histologic differentiation and stage of disease in these neoplasms. In conclusion, (1) chromosomal aneusomy characterizes most DNA diploid (DI = 1.00) and all DNA aneuploid (DI < or > 1.00) head and neck squamous carcinomas; (2) polysomy is the most prevalent finding; (3) loss of the Y chromosome in tumors from male patients is a consistent feature; (4) the FCM DI reflects net chromosomal gains or losses in these neoplasms; and (5) DNA aneuploidy is associated with tumor aggressiveness.

The dose-dependent effect of misoprostol on indomethacin-induced renal dysfunction in well compensated cirrhosis

Misoprostol (200 micrograms) has been shown to acutely counteract the indomethacin-induced renal dysfunction in well compensated cirrhotic patients. The aim of this study was to determine if the prophylactic value of misoprostol was dose-dependent. Parameters of renal hemodynamics and tubular sodium and water handling were assessed by clearance techniques in 26 well compensated cirrhotic patients before and after an oral combination of 50 mg of indomethacin and various doses of misoprostol. The 200-micrograms dose was able to totally abolish the deleterious renal effects of indomethacin, whereas the 800-micrograms dose resulted in significant worsening of renal hemodynamics and sodium retention. These changes were maximal in the hour immediately after medications and slowly returned toward base-line levels thereafter. These results suggest that the renal protective effects of misoprostol is dose-dependent. However, until this apparent ability of 200 micrograms of misoprostol to prevent the adverse effects of indomethacin on renal function is confirmed with chronic frequent dosing, it would be prudent to avoid nonsteroidal anti-inflammatory therapy in patients with cirrhosis.

Isocitrate dehydrogenase from bovine heart: primary structure of subunit 3/4

Bovine NAD(+)-dependent isocitrate dehydrogenase was shown previously to contain four subunits of approx. 40 kDa (subunits 1-4) possessing different peptide maps and electrophoretic properties [Rushbrook and Harvey (1978) Biochemistry 17, 5339-5346]. In this study the heterogeneity is confirmed using enzyme purified by updated methods and from single animals, ruling out allelic variability. Subunits 1 and 2 were differentiated from each other and from subunits 3 and 4 by N-terminal amino acid sequencing. Subunits 3 and 4 (subunits 3/4) were identical in sequence over 30 residues. The N-terminal residues of subunits 1 and 2 were homologous but not identical with the beta- and gamma-subunits respectively of the comparable pig heart enzyme. Subunits 3/4 were identical over 30 residues with the N-terminus of the pig heart alpha-subunit. Full-length sequence, including that for mitochondrial import, is presented for a protein with the processed N-terminus of subunits 3/4, deduced from cloned cDNA obtained utilizing the N-terminal sequence information. The derived amino acid sequence for the mature protein contains 339 amino acids and has a molecular mass of 36,685 Da. Complete identity with N-terminal and Cys-containing peptides totalling 92 residues from the alpha-subunit of the pig heart enzyme [Huang and Colman (1990) Biochemistry 29, 8266-8273] suggests that maintenance of a particular three-dimensional structure in this subunit is crucial to the function of the enzyme. An electrophoretic heterogeneity within the pig heart alpha-subunit, similar to that shown by bovine subunits 3/4, was demonstrated. One reordering of the Cys-containing peptides of the pig heart alpha-subunit is indicated. Sequence comparison with the distantly related NADP(+)-dependent enzyme from Escherichia coli, for which the three-dimensional structure is known [Stoddard, Dean and Koshland (1993) Biochemistry 32, 9310-9316] shows strong conservation of residues binding isocitrate, Mg2+ and the NAD+ moiety of NADP+, consistent with a catalytic function.

The effect of misoprostol on indomethacin-induced renal dysfunction in well-compensated cirrhosis

BACKGROUND/AIMS

Indomethacin has been shown to have adverse effects on renal function in patients with well-compensated alcoholic cirrhosis. The aim of this study was to determine whether an oral prostaglandin E1 analogue, misoprostol, could prevent this indomethacin-induced renal dysfunction.

METHODS

Six patients with well-compensated alcoholic cirrhosis were studied. Renal hemodynamics and tubular function were assessed by clearance techniques before and after an oral dose of (i) 50 mg of indomethacin alone (I50), and (ii) a combination of I50 and 200 micrograms of misoprostol.

RESULTS

I50 produced a significant reduction in glomerular filtration rate, a fall in effective renal plasma flow and an increase in renal vascular resistance. Two hundred micrograms of misoprostol was able to abolish the deleterious renal effects of indomethacin totally, yielding an increase in glomerular filtration rate and effective renal plasma flow and a decrease in renal vascular resistance as well as an increase in urinary volume and urinary sodium excretion. These beneficial effects were maximal in the hour immediately following medication, but were only transient, and this may be a limiting factor in its clinical use.

CONCLUSIONS

If the beneficial renal effects of misoprostol could be confirmed after chronic administration, then the vasodilatory, natriuretic and diuretic potential of 200 micrograms of misoprostol could be of potential therapeutic value in patients with well-compensated alcoholic cirrhosis who require non-steroidal anti-inflammatory drug therapy.

Low CO2 stimulates inositol phosphate turnover and increased inositol 1,4,5-trisphosphate levels in piglet cerebral microvascular smooth muscle cells

In contrast to hypercapnic dilation, hypocapnia-induced cerebral vasoconstriction does not involve prostanoids in newborn pigs. The hypothesis that increased pH or decreased CO2 tension increases inositol phosphate turnover in piglet cerebral microvascular smooth muscle (SM) cells was addressed to begin to assess the possibility that this second-messenger system is involved in hypocapnia-induced cerebral vasoconstriction. Cerebral microvascular SM cells in primary culture prelabeled with [3H]-myoinositol were stimulated for 30 sec with artificial cerebrospinal fluid of increased or normal pH, (7.80 vs 7.40), constant PCO2 36 mm Hg. Following extraction from cells, radiolabeled inositol phosphates were separated by HPLC. These metabolic alkalosis studies were repeated using an inositol 1,4,5-trisphosphate (Ins[1,4,5]P3 protein-binding assay (PBA). Respiratory alkalosis using aCSF with pH 7.60, PCO2 20 mm Hg versus control pH 7.40, PCO2 36 mm Hg was similarly tested with PBS measurement of Ins(1,4,5)P3. aCSFs of control pH 7.40, and PCO2s of 70, 36, or 25 mm Hg were studied both by [3H]-myoinositol (HPLC) and PBA to further determine the importance of CO2 tension, in the presence of fixed pH, on Ins(1,4,5)P3 production. When PCO2 was constant, inositol phosphate turnover (as measured by [3H]-Ins[1,4,5]P3 accumulation) increased when pH was increased from 7.40 to 7.80 at 30 sec of stimulation. Mean [3H]-Ins(1,4,5)P3 accumulation at pHs of 7.40 and 7.80, constant PCO2 of 36 mm Hg, were 2.9 +/- 0.7 and 4.1 +/- 0.8 cpm/micrograms protein, respectively. Ins(1,4,5)P3 levels for pH of 7.40 or 7.80 and constant PCO2 of 36 mm Hg, were 25.4 +/- 1.8 and 38 +/- 8 pmol/well, respectively, by PBA. Respiratory alkalosis also increased Ins(1,4,5)P3 levels. For pH of 7.40, PCO2 36 mm Hg and pH 7.60, PCO2 20 mm Hg, Ins(1,4,5)P3 levels were 37.6 +/- 16 and 64.1 +/- 25 pmol/well, respectively. Decreasing CO2 tension (from 70 mm Hg to 25 mm Hg) in the presence of fixed pH 7.40 failed to increase Ins(1,4,5)P3 levels. The present data demonstrate that decreased CO2 tension stimulates an increase in Ins(1,4,5)P3 production in piglet cerebral microvascular smooth muscle cells. Increasing pH via lower PCO2 increases the level of Ins(1,4,5)P3 even more than increasing pH with fixed base, but extracellular pH appears to be important since decreased PCO2 without changing extracellular pH had no effect. We conclude that the inositol phosphate second messenger system in cerebral microvascular smooth muscle responds appropriately to acute alkalosis to be involved in hypocapnia-induced cerebral vasoconstriction.

An expert system based preventive medicine examination adviser

Periodic preventive medicine examinations generally rely on a standardized approach. In addition, they are often performed by physicians with only limited training in preventive medicine. Evaluation of a corporate-based program led to the prototype development of an artificial intelligence (AI)-based expert system to collect information from employees and make very specific recommendations for primary practitioners. Unique features include the customizing of questions for each subject and the selection of information to be acquired, both based on answers to previous questions. Recommendations are highly person specific and fall into four categories: laboratory testing, primary physician testing, counseling, and referral. The AI approach allows for easy updating of recommendations in order to meet changes in local preventive resources and national recommendations.

Mechanisms of hypercapnia-stimulated PG production in piglet cerebral microvascular endothelial cells

High CO2 stimulates dilator prostanoid (prostaglandin; PG) synthesis by piglet cerebral microvascular endothelial cells, but the mechanism of stimulation is unclear. We address the hypothesis that intracellular pH (pHi) and Ca2+ signaling are involved. When extracellular pH (pHe) and PCO2 were constant and pHi was rapidly reduced (propionate or nigericin), PG synthesis was stimulated. When pHe was lowered by reducing NaHCO3, pHi fell slowly, but PG synthesis was not altered. When pHe was decreased by increasing PCO2 or returned to 7.4 by increasing NaHCO3, with a constant PCO2 of 100 mmHg, pHi dropped quickly and PG synthesis was stimulated. When pHi was reduced slowly by changing CO2 slowly, or by stepwise addition of propionate, PG synthesis was increased regardless of pHe, suggesting that the rapid decline of pHi plays a central role in mediating the PG synthesis. Ca2+ signaling is a potential mechanism by which pHi increases PG synthesis. However, extracellular Ca2+ removal did not affect PG synthesis induced by propionate or hypercapnia. Furthermore, neither rapid nor slow decreases of pHi altered cytosolic free Ca2+ concentration. Therefore, Ca2+ signals do not appear to be involved in the CO2 stimulation of PG synthesis.

Temperature sensitive simian virus 40 large T antigen immortalization of murine odontoblast cell cultures: establishment of clonal odontoblast cell line

During tooth formation instructive epithelial-mesenchymal interactions result in the cytodifferentiation of ectomesenchymal cells into odontoblasts which produce the dentin extracellular matrix (DECM). The purpose of our study was to establish a stable murine odontoblast cell line by immortalization of odontoblasts using retrovirus transfection. In order to accomplish this goal, we utilized a previously characterized odontoblast monolayer cell culture system supportive of odontoblast cytodifferentiation from dental papilla mesenchyme (DPM), expression and secretion of a DECM and dentin biomineralization. First mandibular molars from E-18 Swiss Webster mice were dissected, the DPM isolated, and pulp cells dissociated. Pulp cells (5 x 10(5)/well) were plated as monolayers and grown in alpha-MEM supplemented with 10% FCS, 100 units/ml penicillin and streptomycin, 50 micrograms/ml ascorbic acid. Cultures were maintained for 6 days at 37 degrees C in a humidified atmosphere of 95% air and 5% CO2, with media changes every two days. Immortalization was performed using a recombinant defective retrovirus containing the temperature sensitive SV-40 large T antigen cDNA and the neomycin (G418) resistance gene recovered from CRE packaging cells. Cultures were infected for 24 h with CRE conditioned medium containing 8 micrograms/ml of polybrene, the media was replaced with selective media containing 300 micrograms/ml of G418, and the cultures incubated at 33 degrees C for one month with media changes every 3-5 days. Neomycin resistant cells were cloned by serial dilution to single cells in 96-well culture plates and grown in selection medium at 33 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)