Predicting human brain activity associated with the meanings of nouns

The question of how the human brain represents conceptual knowledge has been debated in many scientific fields. Brain imaging studies have shown that different spatial patterns of neural activation are associated with thinking about different semantic categories of pictures and words (for example, tools, buildings, and animals). We present a computational model that predicts the functional magnetic resonance imaging (fMRI) neural activation associated with words for which fMRI data are not yet available. This model is trained with a combination of data from a trillion-word text corpus and observed fMRI data associated with viewing several dozen concrete nouns. Once trained, the model predicts fMRI activation for thousands of other concrete nouns in the text corpus, with highly significant accuracies over the 60 nouns for which we currently have fMRI data.

Endoscopy-related infections and toxic reactions: an international comparison

This article is an analysis of the characteristics of exogenous endoscopy-related infections, pseudoinfections, and toxic reactions that have occurred worldwide during the period 1974 - 2004. A systematic review of the scientific literature published between 1966 and 2004 was conducted in Medline and the Food and Drug Administration Reports database, using a prospective protocol developed by the authors. The literature review identified 140 outbreaks, reported in 134 scientific articles. More than 94 % of the outbreaks identified could have been prevented by improved decontamination processes. Proper decontamination practices and the improvement of surveillance systems could reduce the clinical burden associated with exogenous endoscopy-related events.

Nevus Lipomatosus (Pedunculated Lipofibroma) of the Eyelid

Nevus lipomatosus is a rare connective tissue nevus characterized by mature adipose tissue within the dermis. An 11-year-old boy presented with an eyelid papule that had been observed expectantly since birth and had exhibited gradual and progressive enlargement. Excisional biopsy revealed a polypoid mass formed of mature adipocytes within the dermis and subconjunctival mucosa consistent with nevus lipomatosus. This is the first case of nevus lipomatous to our knowledge to be reported on the eyelid. Nevus lipomatous or pedunculated lipofibroma can arise on the eyelid and should be considered in the differential diagnosis of eyelid tumors.

The notch receptor and its ligands are selectively expressed during hematopoietic development in the mouse

Members of the Notch family of transmembrane receptors are found on primitive hematopoietic precursors, and Notch ligand expression has been demonstrated on the surface of stromal cells, suggesting a role for Notch signaling in mammalian blood cell development. The current report examines the expression of Notch receptors and their ligands in murine hematopoietic tissues to determine: A) which blood cell lineages in the adult are influenced by Notch activity, and B) whether fetal hematopoiesis in the embryo involves the Notch pathway. In the adult mouse, a combination of flow cytometry, immunohistochemistry and Northern analysis was used to examine Notch receptor or ligand expression in bone marrow and spleen. In the embryo, Northern analysis and in situ hybridization were used to characterize Notch receptor and ligand expression in fetal liver on embryonic day 12 (E12) through E17, an active period encompassing both erythropoiesis and granulopoeisis. Flow cytometry demonstrated the presence of Notch1 and Notch2 receptors on bone marrow-derived myeloid cells but not on erythroid cells positive for the marker, Ter-119. In situ hybridization of E12 through E17 fetal liver demonstrated widespread expression of Jagged1 and Delta1 in a pattern similar to but less abundant than that of the erythropoietin receptor. Taken together with earlier functional results, the current expression data suggest a role for Notch activity in establishing definitive hematopoiesis in fetal liver, as well as a selective use of Notch signaling in adult erythropoiesis and granulopoiesis. Notch receptors in the adult are most likely utilized by early erythroid precursors and intermediate-stage granulocytes, but not by terminally differentiating cells of either subset.

Prenatal diagnosis for congenital adrenal hyperplasia in 532 pregnancies

Congenital adrenal hyperplasia (CAH) refers to a family of monogenic inherited disorders of adrenal steroidogenesis most often caused by enzyme 21-hydroxylase deficiency (21-OHD). In the classic forms of CAH (simple virilizing and salt wasting), androgen excess causes external genital ambiguity in newborn females and progressive postnatal virilization in males and females. Prenatal treatment of CAH with dexamethasone has been successfully used for over a decade. This article serves as an update on 532 pregnancies prenatally diagnosed using amniocentesis or chorionic villus sampling between 1978 and 2001 at New York Presbyterian Hospital-Weill Medical College of Cornell University. Of the 532 pregnancies, 281 were prenatally treated for CAH due to the risk of 21-hydroxylase deficiency. Follow-up telephone interviews with mothers, genetic counselors, endocrinologists, pediatricians, and obstetricians were performed in all cases. Of the pregnancies evaluated, 116 babies were affected with classic 21-OHD. Of these, 61 were female, 49 of whom were treated prenatally with dexamethasone. Dexamethasone administered at or before 9 wk gestation (in proper doses) was effective in reducing virilization. There were no statistical differences in the symptoms during pregnancy between mothers treated with dexamethasone and those not treated with dexamethasone, except for weight gain, edema, and striae, which were greater in the treated group. No significant or enduring side-effects were noted in the fetuses, indicating that dexamethasone treatment is safe. Prenatally treated newborns did not differ in weight from untreated, unaffected newborns. Based on our experience, prenatal diagnosis and proper prenatal treatment of 21-OHD are effective in significantly reducing or eliminating virilization in the newborn female. This spares the affected female the consequences of genital ambiguity, genital surgery, and possible sex misassignment.

Prenatal diagnosis for congenital adrenal hyperplasia in 532 pregnancies

Congenital adrenal hyperplasia (CAH) refers to a family of monogenic inherited disorders of adrenal steroidogenesis most often caused by enzyme 21-hydroxylase deficiency (21-OHD). In the classic forms of CAH (simple virilizing and salt wasting), androgen excess causes external genital ambiguity in newborn females and progressive postnatal virilization in males and females. Prenatal treatment of CAH with dexamethasone has been successfully used for over a decade. This article serves as an update on 532 pregnancies prenatally diagnosed using amniocentesis or chorionic villus sampling between 1978 and 2001 at New York Presbyterian Hospital-Weill Medical College of Cornell University. Of the 532 pregnancies, 281 were prenatally treated for CAH due to the risk of 21-hydroxylase deficiency. Follow-up telephone interviews with mothers, genetic counselors, endocrinologists, pediatricians, and obstetricians were performed in all cases. Of the pregnancies evaluated, 116 babies were affected with classic 21-OHD. Of these, 61 were female, 49 of whom were treated prenatally with dexamethasone. Dexamethasone administered at or before 9 wk gestation (in proper doses) was effective in reducing virilization. There were no statistical differences in the symptoms during pregnancy between mothers treated with dexamethasone and those not treated with dexamethasone, except for weight gain, edema, and striae, which were greater in the treated group. No significant or enduring side-effects were noted in the fetuses, indicating that dexamethasone treatment is safe. Prenatally treated newborns did not differ in weight from untreated, unaffected newborns. Based on our experience, prenatal diagnosis and proper prenatal treatment of 21-OHD are effective in significantly reducing or eliminating virilization in the newborn female. This spares the affected female the consequences of genital ambiguity, genital surgery, and possible sex misassignment.

Relative safety of mirtazapine overdose

A 43-y-o male with a history of AIDS, atrial fibrillation, and alcohol abuse presented to the emergency department 2 h after ingestion of 25 tablets of 15 mg mirtazapine (total 375 mg) with ethanol in a suicide attempt (no other coingestion). Vital signs were normal except for a mild tachycardia (rate 112). Physical examination was unremarkable except for lethargy. Fifty grams of activated charcoal with sorbitol was given. Electrocardiogram showed sinus tachycardia, left ventricular hypertrophy, and non-specific ST-segment changes. Serum mirtazapine on admission was 530 ng/mL (therapeutic level 20-50 ng/mL). Overnight monitoring revealed no tachyarrythmias, and discharge occurred after psychiatric evaluation. It appears that ingestions of mirtazapine approximately 10-fold of therapeutic exhibit minimal acute toxicity. From this and other cases in the literature exhibiting a 10-fold overdose, we conclude that isolated mirtazapine ingestions of this magnitude require no acute intervention other than short term (about 6 h) observation.

Evaluation of cross-protection afforded by a Salmonella Choleraesuis vaccine against Salmonella infections in pigs under field conditions

This field study investigated the efficacy of a Salmonella Choleraesuis live vaccine (Argus SC) to reduce the number of infections with Salmonella. Twelve groups of about 380 pigs each were randomly allocated to either vaccination (V) or no vaccination (C). The vaccine was applied orally at 3 and 16 weeks. Forty pigs per group were blood sampled at 3, 10, 16, and 24 weeks to detect possible antibodies against Salmonella. The prevalence of Salmonella in the lymph nodes was the major variable. In the V groups, only 0.6% of the lymph nodes were positive, whereas 7.2% were positive in the C groups (p < 0.001). The percentage of seropositive pigs at 24 weeks (cut-off OD > 10) was 26% and 9% in the V and C groups, respectively (p < 0.001). The present study documented that vaccination with a live modified S. Choleraesuis vaccine is a useful tool to lower the prevalence of Salmonella in swine herds.

Emergency medicine standardized letter of recommendation: predictors of guaranteed match

OBJECTIVE

The Council of Emergency Medicine Residency Directors (CORD) standardized letter of recommendation (SLOR) has become a common, reliable, and useful tool in the evaluation of emergency medicine (EM) applicants. A "guaranteed match" (GM) is the SLOR's bottom-line superlative response. It is also the SLOR's least common superlative response. Because candidates receiving a GM are a select group, the authors thought it would be useful to identify SLOR information that predicts a GM recommendation.

METHODS

This was a secondary analysis of a database of all EM SLORs submitted to a single EM residency during the 1998--1999 application cycle to one EM residency program. Response to GM and 16 data points in the background/qualification sections were analyzed by chi-square, univariate analysis, and logistic regression.

RESULTS

Four hundred eleven SLORs were analyzed. Qualification information was more predictive than background information for applicants receiving a GM. The highest univariate odds ratios for background information were "staff author" (OR = 1.7, 1.0--2.8), "extended contact" (OR = 2.2, 1.0--4.5), "clinical contact outside the ED" (OR = 3.0, 1.5--5.9), and "honors on EM rotation" (OR = 5.4, 3.0--9.8). The highest univariate odds ratios for qualification information were "outstanding differential diagnosis ability" (OR = 10.1, 5.8--17.4), "outstanding work ethic" (OR = 13.1, 5.2--33.3), and "outstanding global assessment" (OR = 58, 24.2--139). Logistic regression analysis demonstrated "outstanding global assessment" (p < 0.000; r = 0.92) and "outstanding work ethic" (p = 0.028; r = 0.71) to be statistically predictive of GM.

CONCLUSIONS

There were both background and qualification data points predictive of a "guaranteed match." Qualification information had a greater predictive value than background information. Medical student applicants, letter writers, and letter evaluators may find this information useful when dealing with SLORS.

Family characteristics and life events before the onset of autoimmune type 1 diabetes in young adults: a nationwide study

OBJECTIVE

To elucidate whether family characteristics and stressful life events were associated with onset of autoimmune type 1 diabetes in young adults.

RESEARCH DESIGN AND METHODS

This investigation was based on a nationwide study (Diabetes Incidence Study in Sweden) of newly diagnosed patients aged 15-34 years. Patients clinically classified as type 1 diabetic with antibodies to islet cells and/or to GAD65 were compared with age- and sex-matched control subjects via questionnaire. The questionnaire covered diabetes heredity, social environment, educational level, and life events experienced during the 12 months before diagnosis.

RESULTS

The rate of response was 82% for the diabetic patients and 65% for the control subjects. Questionnaires from 349 diabetic patients and 979 control subjects were considered. Diabetes in relatives was more frequent in the patients (odds ratio [OR]2.6) who were born in Sweden and whose mothers were of Swedish origin. No major stress factors were detected in the diabetic patients; however, in comparison with the control subjects, the diabetic patients had experienced fewer conflicts with their parents and had less often broken contacts with friends.

CONCLUSIONS

Young adults with recent-onset type 1 diabetes were more exposed to heredity for diabetes, but no major prediabetic stress factors were detected. Our study does not directly support the concept that psychosocial stressful life events are involved in the development of autoimmune type 1 diabetes in young adults.

Genetic diversity and fitness in peripheral and central populations of the European tree frog Hyla arborea

Genetic diversity is expected to decrease in small and isolated populations as a consequence of founder effects, bottlenecks, inbreeding and genetic drift. In this study we analyse temporal and spatial effects on genetic variation and progeny viability of the European tree frog (Hyla arborea) at two scales. First, the Swedish distribution has been isolated from the continental distribution for more than 8000 thousand years, and secondly, within Sweden, recent habitat alterations that have taken place during this century have increased isolation between local populations. Genetic variation and progeny survival in relation to isolation was studied within the entire Swedish distribution of the tree frog. Allozyme electrophoresis analysis of froglets, sampled across the Swedish distribution, revealed a low overall genetic variation (1.06 alleles/locus) at the protein level in comparison with continental populations (1.54-1.68 alleles/locus). However, egg hatchability (97%) and early larval survival (95%) were not lower than in other parts of the tree frog distribution or in other anuran species. Within the Swedish distribution, early larval survival was lower in isolated breeding ponds than in more central ones. However, no differences in genetic variation were found in relation to isolation. Polymorphism was detected only at a single locus, and was restricted geographically to the eastern part of the Swedish distribution. Bottlenecks due to climatic changes and fragmentation of suitable habitat (primarily natural pastures with ponds) are suggested as possible causes of the low genetic diversity of the Swedish tree frog population.

Wavelength-dependent measurements of optical-fiber transit time, material dispersion, and attenuation

A new, to our knowledge, method for measuring the wavelength dependence of the transit time, material dispersion, and attenuation of an optical fiber is described. We inject light from a 4-ns rise-time pulsed broadband flash lamp into fibers of various lengths and record the transmitted signals with a time-resolved spectrograph. Segments of data spanning a range of approximately 3000 A are recorded from a single flash-lamp pulse. Comparison of data acquired with short and long fibers enables the determination of the transit time and the material dispersion as functions of wavelength dependence for the entire recorded spectrum simultaneously. The wavelength-dependent attenuation is also determined from the signal intensities. The method is demonstrated with experiments using a step-index 200-mum-diameter SiO(2) fiber. The results agree with the transit time determined from the bulk glass refractive index to within ?0.035% for the visible (4000-7200-A) spectrum and 0.12% for the UV (2650-4000-A) spectrum and with the attenuation specified by the fiber manufacturer to within ?10%.

Role of molecular biology in diagnostic pathology of melanoma

Cutaneous melanoma is the most rapidly increasing malignancy in the white European population; its clinical significance is enhanced because it can affect younger individuals (1-3). The high mortality rate among melanoma patients, second to lung cancer, is related to melanoma's resistance to therapy once the metastastic process has started (4-6). The tumor derives from epidermal melanocytes, either activated or genetically altered; thus, important precursors include activated melanocytes present within solar lentigo or forming prema- lignant lesions such as lentigo maligna (7-10). Melanoma can also arise from relatively benign or atypical nevomelanocyte lesions (7-10). Benign lesions that can nevertheless result in melanoma include congenital melanocytic nevus, nevus of Ota, nevus of Ito, and cellular blue nevus. The atypical lesions with the same possible outcome are represented by acquired dysplastic melanocytic nevus, melanocytic dysplasia on the acral or mucosal surface, spindle cell and/or atypical epithelioid melanocytic nevus (Spitz nevus), and dysplastic and/or congenital nevus spilus (7-10).

Human skin expresses growth hormone but not the prolactin gene

Using sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) methods, we showed the expression of mRNA for growth hormone (GH) but not prolactin (PRL) in whole human skin (normal and basal cell carcinoma (BCC)). These RNAs for PRL and GH were below detectability in human epidermal keratinocytes and in human and hamster malignant melanocytes. This is in agreement with previous studies showing GH gene expression in dermal fibroblasts. GH peptide was not detected (by immunocytochemistry) in human skin specimens (normal and pathologic) in either dermal or epidermal compartments. The mRNA coding for the GH mediator insulin-like growth factor-1 (IGF-1) was detectable in whole skin and in malignant melanocytes. Therefore, in the present investigation of hormonal mediators of the cutaneous (epidermal) response to environmental stress, we have excluded the direct participation of PRL and GH in that reaction. Thus the analogy previously noted between the systemic (central) and skin responses to stress, as represented by cutaneous expression of hypothalamic-pituitary-adrenal axis components, does not extend to other pituitary hormones also involved in that response such as PRL and GH.

Calculating the costs of gun injuries. A new methodology

A new method for assessing the costs of gun injuries to a health system examines data on paid amounts, comprehensive medical expenses, and expenses over time. The authors extracted claims using injury diagnosis codes from billing forms and medical charts. The study demonstrates that a claims database can be used to accurately measure health care costs associated with gun injuries. The study is the first to include gun-related injuries treated in ambulatory care settings and to track actual payments over time.

Extinction dynamics and the regional persistence of a tree frog metapopulation

The concept of a metapopulation acknowledges local extinctions as a natural part of the dynamics of a patchily distributed population. However, if extinctions are not balanced by recolonizations or if there is a high degree of spatial synchrony of local extinctions, this poses a threat to and will reduce the metapopulation persistence time. Here we show that, in a metapopulation network of 378 pond patches used by the tree frog (Hyla arborea), even though extinctions are frequent (mean extinction probability p(e) = 0.24) they pose no threat to the metapopulation as they are balanced by recolonizations (p(c) = 0.33). In any one year there was a pattern of large populations tending to persist while small populations became extinct. The total number of individuals belonging to populations that went extinct was small (< 5%) compared with those populations that persisted. A spatial autocorrelation analysis indicated no clustering of local extinctions. The tree frog metapopulation studied consisted of a set of larger, persistent populations mixed with smaller populations characterized by high turnover dynamics.

Clinicopathologic reassessment of primary cutaneous B-cell lymphomas with immunophenotypic and molecular genetic characterization

Primary cutaneous B-cell lymphomas (PCBLs) may have particular clinicopathologic characteristics distinct from their lymph node-based counterparts. It has been suggested that PCBLs should have a separate classification system. The aim of this study was to determine whether the Revised European-American Lymphoid Neoplasms (REAL) classification is applicable to PCBL. Thirty-nine cases of PCBL from 36 patients, consisting of 20 men and 16 women (median age 66 yrs), were included in this study. Paraffin-section immunohistochemistry for CD3, CD5, CD10, CD20, CD43, Bcl-2, Bcl-6, and cyclin D1 was performed in all cases. Immunostaining for immunoglobulin light chains was also performed on cases histologically diagnosed as extranodal marginal zone lymphoma (MZL) and primary cutaneous B-cell lymphoma unclassifiable (PCBLu). Polymerase chain reaction (PCR) analysis of t(14;18) was performed in all cases. Immunoglobulin heavy chain gene rearrangement (VDJ) was tested by PCR on all follicle center lymphoma (FCL), MZL, and PCBLu cases. The 39 cases consisted of 15 (39%) FCLs, 13 (33%) diffuse large B-cell lymphomas (DLCL), 9 (23%) extranodal MZL, and 2 cases of PCBLu. Anatomically, 59% of PCBLs occurred in the head and neck, of which approximately 57% were FCL. Five of six cases presenting on the lower extremity were DLCL. Follow-up data was available from all 39 patients with a mean of 50.8 months. All but two patients are alive with or without disease at last contact. One patient with DLCL died of lung metastases and the other DLCL patient died of sepsis as a complication of therapy. In all 15 cases of FCL, CD10 and/or Bcl-6 expression supported the follicle center origin of the neoplastic cells. In contrast to previous reports, we found that 53% (8 of 15) of primary cutaneous FCL had either Bcl-2 protein expression or t(14;18). Our data indicate that many cases of primary cutaneous FCL have Bcl-2 alterations similar to their nodal counterpart. We found that 95% (37 of 39) of PCBLs could be classified according to the REAL classification, supporting its applicability in cutaneous lymphomas.

Molecular pathology of soft tissue and bone tumors. A review

OBJECTIVE

To present recent concepts on the molecular pathogenesis of tumors of soft tissue and bone, and on the use of molecular genetic methods, including their significance as diagnostic markers and prognostic indicators.

DATA SOURCES AND STUDY SELECTION

Reports on tumors of bone and/or soft tissue published in the English language literature and observations made using specimens available at the Departments of Pathology at Albany Medical College and Loyola University Medical Center.

DATA EXTRACTION AND SYNTHESIS

Studies on bone and soft tissue tumors containing chromosomal or genetic evaluation were selected for further analysis. Specific chromosomal abnormalities, such as numerical aberrations or translocations with production of fusion genes, were classified according to the tumor of origin. Data were also collected on mutations in tumor suppressor genes, genes coding for growth factors or their receptors, and genes coding for tyrosine kinases. Also noted were mutations of uncertain significance, for which the pathogenic connection between tumor production and mutated gene function is still unclear.

CONCLUSIONS

In general, the mutations reported interfere with the action of peptide growth factors coordinating mesenchyme proliferation and differentiation, although membrane-bound receptors expressing the intracellular signaling modifier, tyrosine kinase activity, have also been involved. Functional types of genes most commonly affected include tumor suppressors, oncogenes, and nuclear transcription factors. Thus, the mutations involved in the pathogenesis of soft tissue and bone tumors have affected multiple genes. Moreover, aberrant fusion gene products may be formed in tumoral tissue and may then act as transcription regulators stimulating cellular proliferation. Cytogenetic studies help at the clinical level by demonstrating aneuploidy and increased ploidy, which may correlate with malignant behavior. Diagnostic tumor-specific chromosomal translocations may be detected with Southern hybridization analysis, polymerase chain reaction, reverse-transcription polymerase chain reaction, or with the fluorescence in situ hybridization technique. Notably, early metastatic disease may be detectable in blood specimens using polymerase chain reaction or reverse-transcription polymerase chain reaction techniques.

Polarity of 11-cis retinal release from cultured retinal pigment epithelium

PURPOSE

Fetal bovine retinal pigment epithelium (RPE) was grown on porous supports to investigate the polarity of 11-cis retinal (RAL) release from these cells and the influence that the interphotoreceptor retinoid-binding protein (IRBP) has on this process.

METHODS

[3H]all-trans retinol (ROL) was delivered to the basal surface of the cultured RPE by serum retinol-binding protein (RBP). Apo IRBP was added to either the apical or basal medium, or was absent from the incubation entirely.

RESULTS

The greatest level of [3H]11-cis RAL was detected in the apical medium but only when apo IRBP was present there. When apo IRBP was present only in the basal medium, or was absent from the incubation entirely, low levels of [3H]11-cis RAL were released apically and basally.

CONCLUSIONS

If 11-cis RAL release were constitutive, one would expect to find elevated levels of this retinoid in the apical and basal media in the absence of apo IRBP. Instead, the enhancement of [3H]11-cis RAL release into the apical, but not the basal, medium in the presence of apo IRBP suggests that [3H]11-cis RAL release is polarized and dependent on the presence of apo IRBP. It is postulated, therefore, that a mechanism such as an IRBP membrane receptor in the apical plasma membrane may be responsible for this polarity.

Structural and functional characterization of recombinant human cellular retinaldehyde-binding protein

Cellular retinaldehyde-binding protein (CRALBP) is abundant in the retinal pigment epithelium (RPE) and Müller cells of the retina where it is thought to function in retinoid metabolism and visual pigment regeneration. The protein carries 11-cis-retinal and/or 11-cis-retinol as endogenous ligands in the RPE and retina and mutations in human CRALBP that destroy retinoid binding functionality have been linked to autosomal recessive retinitis pigmentosa. CRALBP is also present in brain without endogenous retinoids, suggesting other ligands and physiological roles exist for the protein. Human recombinant cellular retinaldehyde-binding protein (rCRALBP) has been over expressed as non-fusion and fusion proteins in Escherichia coli from pET3a and pET19b vectors, respectively. The recombinant proteins typically constitute 15-20% of the soluble bacterial lysate protein and after purification, yield about 3-8 mg per liter of bacterial culture. Liquid chromatography electrospray mass spectrometry, amino acid analysis, and Edman degradation were used to demonstrate that rCRALBP exhibits the correct primary structure and mass. Circular dichroism, retinoid HPLC, UV-visible absorption spectroscopy, and solution state 19F-NMR were used to characterize the secondary structure and retinoid binding properties of rCRALBP. Human rCRALBP appears virtually identical to bovine retinal CRALBP in terms of secondary structure, thermal stability, and stereoselective retinoid-binding properties. Ligand-dependent conformational changes appear to influence a newly detected difference in the bathochromic shift exhibited by bovine and human CRALBP when complexed with 9-cis-retinal. These recombinant preparations provide valid models for human CRALBP structure-function studies.

A HPLC method for the determination of 9-cis retinoic acid (ALRT1057) and its 4-oxo metabolite in human plasma

A HPLC method was developed and validated for the quantitation of 9-cis-retinoic acid (ALRT1057) and its major metabolite, 4-oxo-9-cis-retinoic acid (LG100182) in human plasma. Samples were buffered and extracted with methyl-tert-butyl-ether. The analytes and an I.S. were separated on a C18 HPLC column using a shallow gradient of 70-89% organic solvent. The analytes were quantitated by UV detection at 348 nm. Selectivity against endogenous compounds and potential metabolites (retinol, all trans-, 13-cis-, and 4-hydroxy-9-cis-retinoic acid) was demonstrated. The run time was 29 min. The standard curve was linear from 2.5 to 450 ng ml-1. Interassay precision for both analytes in quality control samples was less than 5.0% RSD. Accuracy was within 11.0% RE for both compounds. Analyte stability during sample storage, extraction processing, and chromatography was established. Method ruggedness was tested by two analysts and on two HPLC systems. This method has been applied to the quantitation of clinical samples.

Random and continuous-access immunoassays with chemiluminescent detection by Access automated analyzer

The Access Immunoassay System is an automated random and continuous-access analyzer for use with heterogeneous enzyme immunoassays. The instrument stores refrigerated reagent packs for as many as 24 different immunoassays. Throughput is 50-100 tests per hour. One- and two-step, and sandwich and competitive formats, each with various incubation times, can be accommodated, and sample sizes can vary from 10 to 200 microL. A paramagnetic microparticle solid phase combines with a chemiluminescent substrate for signal generation. Within-run CVs for noninfectious disease assays were 2.0% to 9.2%; total CVs were 3.4% to 11.1%. Regression analysis of method comparison studies with established procedures yielded slopes of 0.84 to 1.12 and correlation coefficients > or = 0.94 for 12 of 14 assays (range 0.83-0.99). Compared with culture methods, the Access assay for Chlamydia in urogenital specimens demonstrated sensitivity, specificity, and positive and negative predictive values of 90%, 99.7%, 95%, and 99%, respectively.

Random and continuous-access immunoassays with chemiluminescent detection by Access automated analyzer

The Access Immunoassay System is an automated random and continuous-access analyzer for use with heterogeneous enzyme immunoassays. The instrument stores refrigerated reagent packs for as many as 24 different immunoassays. Throughput is 50-100 tests per hour. One- and two-step, and sandwich and competitive formats, each with various incubation times, can be accommodated, and sample sizes can vary from 10 to 200 microL. A paramagnetic microparticle solid phase combines with a chemiluminescent substrate for signal generation. Within-run CVs for noninfectious disease assays were 2.0% to 9.2%; total CVs were 3.4% to 11.1%. Regression analysis of method comparison studies with established procedures yielded slopes of 0.84 to 1.12 and correlation coefficients &gt; or = 0.94 for 12 of 14 assays (range 0.83-0.99). Compared with culture methods, the Access assay for Chlamydia in urogenital specimens demonstrated sensitivity, specificity, and positive and negative predictive values of 90%, 99.7%, 95%, and 99%, respectively.

Modulation of cytolytic T cell responses by heparan sulfate

Accumulating evidence suggests that the functional properties of alloactivated T cells may depend upon the microenvironment in which the T cells reside. For instance, we showed previously that heparan sulfate, a biologically active polysaccharide present on cell surfaces and extracellular matrices, modulates the proliferative responses of splenocytes through enhancement of cytokine and prostaglandin production by macrophages. Here we report that under conditions of suboptimal stimulation, heparan sulfate causes discrete alterations in the functional responses of murine cytolytic T cells. When present in a 5-day mixed leukocyte culture (MLC), heparan sulfate mediates an increase, from 3- to 10-fold, in T cell-mediated cytotoxicity. This increase is dose dependent and most pronounced when heparan sulfate is present in the highest concentration during the first 24 hr of the culture period. On the other hand, when added during the last 48-72 hr of an MLC, heparan sulfate decreases cytotoxicity by 3- to 30-fold. Neutralizing antibodies against IL-1 alpha, but not antibodies against IL1 beta, IL-6, or TNF alpha/beta, abrogate the heparan sulfate-mediated increase in cytotoxicity, suggesting that the increase depended in part upon the production of IL-1 alpha. However, studies in which exogenous IL-1 was added to MLC showed that increased cytotoxicity was not due only to increased cytokine production. Augmentation of cytotoxicity was in part independent of T cell help, as depletion of CD4+ cells from the responder population before MLC, or addition of neutralizing anti-murine IL-2 antibodies plus human IL-2 to the MLC, did not abrogate the stimulatory effect of heparan sulfate. Heparan sulfate-treated CD8+ lymphoblasts isolated after 7 days in MLC demonstrated an increased cytotoxicity, elevated intracellular serine esterase, and perforin levels compared with lymphoblasts from control MLC. The decrease in cytotoxicity observed when heparan sulfate was present during the last several days of an MLC was likely mediated by PGE2, as elevated levels of PGE2 were detected in MLC supernatants of heparan sulfate-treated cultures, and because the decrease was not observed in the presence of indomethacin. Our results are consistent with the idea that the metabolism of heparan sulfate, an endogenous component of parenchymal tissues, may regulate the tempo and magnitude of alloreactive cytotoxic T cell responses.

Promotion of the release of 11-cis-retinal from cultured retinal pigment epithelium by interphotoreceptor retinoid-binding protein

This study investigates whether the interphotoreceptor retinoid-binding protein (IRBP) is necessary for the release of 11-cis-retinaldehyde (RAL) or if the retinoid is constitutively released from the retinal pigment epithelium (RPE) following synthesis. The strategic location of IRBP in the interphotoreceptor matrix (IPM) and its retinoid-binding ability make it a candidate for a role in 11-cis-RAL release. Fetal bovine RPE cells were grown in permeable chambers, and their apical surfaces were incubated with medium containing either apo-IRBP, the apo form of cellular retinaldehyde-binding protein (CRALBP), the apo form of serum retinol-binding protein (RBP), or bovine serum albumin (BSA) or with medium devoid of binding proteins. [3H]-all-trans-Retinol (ROL) was delivered to the basal surface of the cells by RBP. High-performance liquid chromatography demonstrated that [3H]-11-cis-RAL was optimally released into the apical medium when apo-IRBP was present. The most surprising result was the diminished level of [3H]-11-cis-RAL when apo-CRALBP was in the apical medium. Circular dichroism demonstrated that CRALBP had not been denatured by the photobleaching required for endogenous ligand removal. Therefore, apo-CRALBP should have been able to bind [3H]-11-cis-RAL if it was constitutively released into the apical medium. In addition, when proteins other than apo-IRBP were present, or if the cells were incubated with medium alone, the observed decrease in apical [3H]-11-cis-RAL was concomitant with a buildup of intracellular [3H]-all-trans-retinyl palmitate and [3H]-all-trans-ROL in the basal culture medium.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytogenetic studies of eight squamous cell carcinomas of the head and neck. Deletion of 7q, a possible primary chromosomal event

Cytogenetic analysis was performed on the metaphase spreads obtained from primary cultures of eight squamous cell carcinomas (SCCa) of the head and neck. Despite a variety of tumor sites and clinical stages, four of eight tumors studied showed the same interstitial deletion of a portion of the q arm of chromosome 7, i.e., del(7)(q22q34). In one tumor, this was the sole chromosome abnormality present. Three tumors showed multiple chromosome rearrangements, including deletion at 7q. Three tumors showed multiple rearrangements but did not have del(7q). One tumor had an apparently, normal karyotype. The implications for del(7q) as a primary chromosomal event in SCCa are discussed.

Release and recovery of porcine pepsin and bovine chymosin from reverse micelles: a new technique based on isopropyl alcohol addition

After complete solubilization by the direct method, porcine pepsin was not released from AOT in isooctane reverse micelles even under aqueous-phase conditions which would not ordinarily allow uptake. Similarly, bovine chymosin, once forward-transferred at a pH below its isoelectric point, was not back-transferred into an aqueous contact phase buffered at a pH value above its isoelectric point. These results show that there is significant hysteresis in the forward- and backward-transfer processes and further imply that kinetics, and not equilibrium, control uptake or release processes for these enzymes. The addition of 10-15% isopropyl alcohol to the aqueous phase increases the rate of protein release dramatically and allows for nearly complete back-transfer of porcine pepsin and 70% back-transfer of bovine chymosin. IPA addition does not destroy the functional integrity of the system since forward transfer of bovine chymosin still occurs at pH values below (but not above) the pI of the protein.

Regulation of murine splenocyte responses by heparan sulfate

Heparan sulfate is a biologically active glycosaminoglycan found in abundance in endothelium, epithelium, and connective tissues. Although heparan sulfate is an important part of the environment in which immune cells function, its effects on the immune system are largely unknown. When present during the first 24 h of an MLC consisting of MHC disparate murine splenocytes, heparan sulfate had a marked stimulatory effect on the proliferative response to alloantigens. Heparan sulfate also augmented the splenocyte response to suboptimal concentrations of the mitogens Con A, anti-CD3 mAb, and ionomycin. The stimulatory action of heparan sulfate was mediated, at least in part, by increased production of IL-1, because the increased splenocyte proliferation induced by heparan sulfate was substantially inhibited by anti-murine IL-1 alpha-antibodies. In contrast to these stimulatory effects, when heparan sulfate was added to MLC 48 to 72 h after onset, decreased splenocyte proliferation was observed. This inhibitory action was mediated by an increase in PGE2 production; the inhibitory effect could be abrogated with indomethacin. The fact that heparan sulfate is present on cells such as endothelial cells with which T cells interact and is released during activation of endothelial cells (thus making it available in soluble form to cells in the immune response) may allow heparan sulfate to play an important role in modulating cell-mediated immune responses in vivo.

Regulation of murine splenocyte responses by heparan sulfate

Heparan sulfate is a biologically active glycosaminoglycan found in abundance in endothelium, epithelium, and connective tissues. Although heparan sulfate is an important part of the environment in which immune cells function, its effects on the immune system are largely unknown. When present during the first 24 h of an MLC consisting of MHC disparate murine splenocytes, heparan sulfate had a marked stimulatory effect on the proliferative response to alloantigens. Heparan sulfate also augmented the splenocyte response to suboptimal concentrations of the mitogens Con A, anti-CD3 mAb, and ionomycin. The stimulatory action of heparan sulfate was mediated, at least in part, by increased production of IL-1, because the increased splenocyte proliferation induced by heparan sulfate was substantially inhibited by anti-murine IL-1 alpha-antibodies. In contrast to these stimulatory effects, when heparan sulfate was added to MLC 48 to 72 h after onset, decreased splenocyte proliferation was observed. This inhibitory action was mediated by an increase in PGE2 production; the inhibitory effect could be abrogated with indomethacin. The fact that heparan sulfate is present on cells such as endothelial cells with which T cells interact and is released during activation of endothelial cells (thus making it available in soluble form to cells in the immune response) may allow heparan sulfate to play an important role in modulating cell-mediated immune responses in vivo.

Dietary omega-3 fatty acids decrease mortality and Kupffer cell prostaglandin E2 production in a rat model of chronic sepsis

We tested the hypothesis that substitution of omega-3 fat for dietary omega-6 fat would reduce mortality and decrease Kupffer cell prostaglandin E2 (PGE2) production in a rat model of chronic sepsis. Rats were fed via gastrostomy for 12 days with isonitrogenous, isocaloric diets containing 15% of calories as either safflower oil (omega-6) or a 10:1 mixture of menhaden oil (omega-3) and safflower oil. After five days of feeding, animals received an intra-abdominal abscess of defined bacterial content. Survivors were killed on post-laparotomy day 6 in conjunction with liver perfusion and protease liver digestion for Kupffer cell isolation. Kupffer cell PGE2 production was measured by radioimmunoassay after 18 hours of cell culture and again after stimulation with 0 LPS, 10 ng/ml LPS, and 10 micrograms/LPS. Mortality was decreased in menhaden oil-fed animals compared with safflower oil-fed animals (16% vs. 35%). Kupffer cell PGE2 production was decreased in menhaden oil-fed animals at 18 hours (354 +/- 54 vs. 570 +/- 95 pg/0.1 ml; p = 0.09) and after stimulation with 10 micrograms/ml LPS (140 +/- 41 vs. 288 +/- 45 pg/0.1 ml; p = 0.03) compared with safflower oil-fed animals.

Diabetes care organization, process, and patient outcomes: effects of a diabetes control program

Effects of a diabetes control program were evaluated in 17 primary health centers after 18 months' participation (17 nonparticipating centers served as controls). Studied were the effects of the program on the organization of diabetes care, on the process of care in terms of services delivered to patients, and on the outcomes of care as measured by improved self-care, dietary knowledge, and HbA1c values. While findings showed that patients from the intervention centers received a higher quality of service and monitored their blood glucose levels more often than did patients from the control centers, they did not demonstrate significantly better metabolic control. The reasons for this, and ways to improve the program are discussed.

Tumor necrosis factor production by Kupffer cells requires protein kinase C activation

Tumor necrosis factor (TNF) has been proposed as a primary inflammatory mediator of septic shock. In vitro and in vivo studies indicate that endotoxin- or lipopolysaccharide (LPS)-activated macrophages are a principle source of TNF; however, membrane signal transduction and intracellular pathways by which LPS triggers TNF production in macrophages are unclear. Recent evidence indicates that specific protein phosphorylation via activation of protein kinase C (PKC) is an early, critical step in the signaling of macrophage TNF production by phorbol esters. We hypothesize that PKC activation is also required in LPS-signaled Kupffer cell (KC) TNF production. Murine KCs were obtained by liver perfusion and digestion and then stimulated with LPS (Escherichia coli O111:B4) or LPS in the presence of H-7, a selective PKC inhibitor. Conditioned media was collected at 3 hr for assay of TNF utilizing the L929 cytolysis bioassay standardized to murine-rTNF-alpha. We found that H-7 inhibited significantly LPS signaled TNF release at a concentration of 10 microM, while H-8 (a cyclic nucleotide specific inhibitor) had no effect. The effect of H-7 was dose dependent and present at varying concentrations of LPS. Down regulation of PKC activity by preincubation of KCs with phorbol myristate acetate (PMA, a direct activator of PKC) also resulted in significantly reduced TNF release after LPS stimulation. The inhibitor H-7 (10 microM) also significantly inhibited LPS signaled prostaglandin E2 release in Kupffer cells. Total and specific intracellular protein phosphorylation was determined by trichloroacetic acid precipitation and SDS-polyacrylamide gel electrophoresis after labeling stimulated Kupffer cells with 32Pi. Total protein phosphorylation was not significantly altered by LPS stimulation; however, autoradiograms from PMA- and LPS-stimulated KCs demonstrate enhanced phosphorylation of a 40-kDa protein (2.7 +/- 0.9-fold) and a 33-kDa protein (3.1 +/- 1.0-fold) which were inhibited by H-7. We conclude that activation of PKC and protein phosphorylation are required steps in the signal transduction pathway of LPS-stimulated TNF production in Kupffer cells.

Use of the Escherichia coli ssb Gene to Prevent Bioreactor Takeover by Plasmidless Cells

Reactor takeover by plasmidless cells is a major problem encountered when producing proteins from plasmid-borne genes in genetically engineered bacteria. We have approached this problem by deleting the essential ssb gene from the Escherichia coli chromosome and placing it on a plasmid. Plasmidless cells do not accumulate even after growing such strains under non-selective continuous culture conditions for extended periods of time. Other ssb-containing plasmids can be readily introduced into this E. coli strain by a plasmid-displacement technique. Using this system, we have achieved very high levels of beta-lactamase production in continuous culture without selective pressure.

Modulation of Kupffer cell membrane phospholipid function by n-3 polyunsaturated fatty acids

Dietary n-3 polyunsaturated fatty acids (PUFAs) have been reported to improve clinical outcome in a number of inflammatory diseases including burns and sepsis. One mechanism contributing to the anti-inflammatory effect is the incorporation of n-3 PUFAs into membrane phospholipids which decreases macrophage eicosanoid production. We hypothesize that an additional mechanism for their effects is an alteration of membrane signal transduction that decreases macrophage responsiveness to inflammatory stimuli. Kupffer cells, the fixed macrophages of the liver, were obtained from rats pair fed diets for 6 weeks with 15% of calories supplied as menhaden (high n-3), corn (control), or safflower (high n-6) oils. The effects of the dietary oils on Kupffer cell membrane signal transduction and eicosanoid production were assessed by measuring inositol phospholipid (PI) metabolism, intracellular calcium responses, and prostaglandin E2 (PGE2) production to the inflammatory signals endotoxin (LPS) and platelet activating factor (PAF). The menhaden oil diet resulted in significant incorporation of n-3 PUFAs into total cellular PUFAs compared to corn and safflower oil. (total n-3 PUFAs, 28.1% menhaden vs 2.1% corn vs 1.2% safflower, P less than 0.03). This incorporation altered signal transduction of PAF as both PI turnover (65% +/- 10% of corn oil) and calcium response (0.6-fold vs 5.0-fold for corn oil) were significantly reduced in the menhaden oil group. (P less than 0.05) The menhaden oil diet also reduced significantly PGE2 production in response to PAF and LPS (corn, 348 +/- 23 pg/ml; menhaden, 48 +/- 6 pg/ml, P less than 0.01). We conclude that, in addition to modulating eicosanoid production, n-3 PUFAs can also alter macrophage membrane signal transduction.(ABSTRACT TRUNCATED AT 250 WORDS)

Natural killer cell activity: age, estrous- and circadian-stage dependence and inverse correlation with metastatic potential

The timing within the estrous cycle of surgical removal of a transplanted murine mammary tumor profoundly influences the frequency of pulmonary metastases. We investigated the potential role of the immune response in this phenomenon by measuring splenic natural killer (NK) cell activity and interleukin-2 (IL-2) production in syngeneic tumor-free mice of two age groups at each of two circadian times and in each of four estrous stages. Estrous stage was determined by assessment of vaginal smear cellularity immediately prior to killing and spleen harvest. In a single-cell splenocyte preparation, NK cytotoxicity against a standard tumor cell target was assessed using a radiolabeled chromium release assay while IL-2 activity was determined in a bioassay utilizing the IL-2-dependent CTLL-2 cell line. Mice from the younger group were found to have eight-fold higher NK activity and 35% greater IL-2 production. After normalization of NK and IL-2 values for age, a highly statistically significant difference in NK activity was found among the four estrous and between the two circadian stages of sacrifice. NK activity was greater during the daily resting span across every estrous stage. IL-2 values were highest in diestrus and proestrus when sampled in the light span and in estrus-metestrus when sampled in the dark. The stages within the fertility cycle associated with lowest metastatic potential (proestrus/estrus) correspond precisely with those of highest splenocyte NK activity. These results indicate that an important component of the cellular immune response varies rhythmically both during the fertility and circadian cycles of the host. The rhythmic changes in NK activity may be in part responsible for the similarly rhythmic frequency of postsurgical metastatic dissemination.

Splenocyte natural killer cell activity and metastatic potential are inversely dependent on estrous stage

We have previously shown that the timing of surgical removal of an estrogen-receptor-bearing mammary adenocarcinoma within the estrous cycle of the female C3HeB/FeJ mouse profoundly influences the frequency of subsequent tumor cell metastasis. In order to investigate the role of the immune response in this phenomenon, we measured splenic natural killer (NK) cell activity and interleukin-2 (IL-2) production in 80 female cycling mice, 16 to 18 weeks old, assigned to one of four estrous stages as determined by relative quantity of vaginal cellularity; proestrus, estrus, metestrus, and diestrus. After prolonged synchronization on 12-hours-on, 12-hours-off light-dark circadian schedules, daily vaginal smears were obtained for 2 weeks to characterize estrous cycling. On the day the animals were killed, vaginal smears were performed and single-cell suspensions were prepared from the harvested spleens. Direct cytotoxicity of spleen cells against the YAC tumor target was assessed immediately in a 3 1/2 hour 51Cr release assay and expressed as NK activity in lytic units (LU 20%). IL-2 production was determined in a bioassay with the IL-2-dependent CTLL-2 cell line. Significant differences in NK activity among estrous stages mimicking the variation found in frequency of surgical cure from mammary adenocarcinoma were observed (p = 0.035; one-way analysis of variance), with the time of lowest metastatic potential corresponding precisely with the time of highest splenocyte NK activity. These both occurred during the proestrus and estrus stages, characterized by high fertility, ovulation, and peak FSH, LH, and estrogen concentrations. In addition, NK activity was found to correlate significantly with IL-2 production (r = 0.4, p less than 0.0005). These results indicate that important components of the cellular immune response to cancer vary rhythmically with hormonal changes in the host and may represent one of the factors affecting the delicate balance between host and tumor that alters the frequency of postsurgical metastatic dissemination.

Health attitudes, self-monitoring of blood glucose, metabolic control and residual insulin secretion in type 1 diabetic patients

The aim of the present cross-sectional study was to determine in patients who have had insulin-dependent diabetes mellitus for a long time, the relationship between residual insulin secretion and self-monitoring of blood glucose, psychological factors, and blood glucose control (HbA1c). In 97 patients with a disease duration of 9-16 years a sample from a 24-h urine collection was analysed for C-peptide excretion. In 35 of these patients an excretion greater than or equal to 0.2 nmol/24 h was detected. They were matched for age at onset and disease duration with patients without any detectable C-peptide excretion. Twenty-nine matched pairs were obtained and 22 of them have been further investigated. HbA1c was lower in the C-peptide excretors than in the non-excretors (6.9 +/- 0.3 vs 7.9 +/- 0.3%) (p less than 0.025). The patients were interviewed by means of a questionnaire dealing with their 'health beliefs'. It was shown that in the group with residual insulin secretion there was a significantly lower perceived risk of developing kidney disease (p less than 0.025) than in the group without residual insulin secretion, but in all other items measured there was no difference between the two groups. Furthermore, in the group with residual insulin secretion we found a correlation (p less than 0.01) of low HbA1c with high frequency of self-monitoring of blood glucose and high perceived vulnerability.(ABSTRACT TRUNCATED AT 250 WORDS)

Beyond CME: diabetes education field-interactive strategies from Sweden

The Diabetes Educational and Training Unit (DETU) at Karolinska Hospital is a permanent, continuing medical education unit working with general practitioners and nurse teams from Stockholm's neigh borhood health centers. It offers a two-week educational program four times a year, teaching a comprehensive approach to diabetes care. Evaluation research found that centers that had implemented the approach taught at the CME course had excellent staff rapport and produced patients who were more knowledgeable about their disease and better able to engage in self-care. As a result of this research, the Stockholm DETU has added innovative field- interactive strategies to stimulate centers that have not implemented the program. These strategies include techniques to enhance staff rapport, increase knowledge and interest in care for people with diabetes, and arrive at staff- determined approaches for organizing diabetes care. Initial evaluation of these strategies indicate encouraging results.

Evaluation of comprehensive program for diabetes care at primary health-care level

The Swedish National Board of Health and Welfare published its first diabetes health-care program in 1977. The impact of the program was evaluated in the Stockholm County after 4 yr. The results showed that the educational program had reached greater than or equal to 1 staff member in 86% of the 104 primary health-care centers (PHCCs). Several organizational changes had taken place as a result of the program. The 10 "best" PHCCs were compared with a random sample of the centers with regard to patient outcomes. Patients from the 10 best centers had gotten a more comprehensive education, were more knowledgeable about foot care, tested glucose more often, and used less medication. The metabolic control was the same for both groups of patients. The PHCC staffs reported the following roadblocks to change: lack of knowledge of diabetes care, insufficient cooperation between staff members, poor contact with specialists, and absence of guidelines for diabetes care. The staffs in the best centers spent twice as much time in staff meetings and continuing education as those from the random sample of centers. The findings led us to formulate a new strategy for the program. The main objective of the new approach is to create organizational changes within the centers. Thus, local knowledge and creativity can be utilized. Preliminary data demonstrate that 84% of the locally developed plans for reorganization of diabetes care had been accomplished within 1 yr.