Metabolic-associated fatty liver disease and hepatocellular carcinoma: a prospective study of characteristics and response to therapy

BACKGROUND AND AIM

The rising incidence of hepatocellular carcinoma (HCC) in Australia is related to increasing rates of metabolic-associated fatty liver disease (MAFLD). This study aimed to prospectively characterize the metabolic profile, lifestyle, biometric features, and response to treatment of HCC patients in an Australian population.

METHOD

Multicenter prospective cohort analysis of newly diagnosed HCC patients at six multidisciplinary team meetings over a 2-year period.

RESULTS

Three hundred and thirteen (313) newly diagnosed HCC patients with MAFLD (n = 77), MAFLD plus other liver disease (n = 57) (the "mixed" group), and non-MAFLD (n = 179) were included in the study. Alcohol-associated liver disease (ALD) (43%) and MAFLD (43%) were the most common underlying liver diseases. MAFLD-HCC patients were older (73 years vs 67 years vs 63 years), more likely to be female (40% vs 14% vs 20%), less likely to have cirrhosis (69% vs 88% vs 85%), showed higher ECOG, and were less likely to be identified by screening (29% vs 53% vs 45%). Metabolic syndrome was more prevalent in the MAFLD and mixed groups. The severity of underlying liver disease and HCC characteristics were the same across groups. While the MAFLD population self-reported more sedentary lifestyles, reported dietary patterns were no different across the groups. Dyslipidemia was associated with tumor size, and those taking statins had a lower recurrence rate.

CONCLUSION

Equal to ALD, MAFLD is now the most common underlying liver disease seen in HCC patients in Australia. Future HCC prevention screening and treatment strategies need to take this important group of patients into consideration.

Groundwater protection and unconventional gas extraction: the critical need for field-based hydrogeological research

Unconventional natural gas extraction from tight sandstones, shales, and some coal-beds is typically accomplished by horizontal drilling and hydraulic fracturing that is necessary for economic development of these new hydrocarbon resources. Concerns have been raised regarding the potential for contamination of shallow groundwater by stray gases, formation waters, and fracturing chemicals associated with unconventional gas exploration. A lack of sound scientific hydrogeological field observations and a scarcity of published peer-reviewed articles on the effects of both conventional and unconventional oil and gas activities on shallow groundwater make it difficult to address these issues. Here, we discuss several case studies related to both conventional and unconventional oil and gas activities illustrating how under some circumstances stray or fugitive gas from deep gas-rich formations has migrated from the subsurface into shallow aquifers and how it has affected groundwater quality. Examples include impacts of uncemented well annuli in areas of historic drilling operations, effects related to poor cement bonding in both new and old hydrocarbon wells, and ineffective cementing practices. We also summarize studies describing how structural features influence the role of natural and induced fractures as contaminant fluid migration pathways. On the basis of these studies, we identify two areas where field-focused research is urgently needed to fill current science gaps related to unconventional gas extraction: (1) baseline geochemical mapping (with time series sampling from a sufficient network of groundwater monitoring wells) and (2) field testing of potential mechanisms and pathways by which hydrocarbon gases, reservoir fluids, and fracturing chemicals might potentially invade and contaminate useable groundwater.

Expression of genes involved in lipogenesis is not increased in patients with HCV genotype 3 in human liver

Hepatitis C virus (HCV) infection is frequently associated with hepatic steatosis, particularly in patients with HCV genotype-3 (HCVGT3). It has variously been hypothesized, largely from in-vitro studies, to be the result of increased synthesis, decreased metabolism and export of triglycerides. We measured by real-time PCR the expression of genes involved in lipid metabolism [acetyl-Coenzyme A carboxylase alpha, apolipoprotein B (APOB), diacylglycerol O-acyltransferase 2, fatty acid-binding protein 1, fatty acid synthase, microsomal triglyceride transfer protein (MTTP), peroxisome proliferator-activated receptor alpha (PPARA), peroxisome proliferator-activated receptor gamma (PPARG), protein kinase AMP-activated alpha 1 catalytic subunit (PRKAA1) and sterol regulatory element-binding transcription factor 1 (SREBF1)] in liver biopsies from patients infected with HCV genotype-1 (HCVGT1), HCVGT3 and Hepatitis B (HBV) using β-glucuronidase (GUSB) and splicing factor arginine/serine-rich 4 (SFRS4) as housekeeping genes. Patients infected with HCVGT3 were younger than those infected with HCVGT1 (36.3 ± 2.5 vs 45.6 ± 1.5, P < 0.05, Mann-Whitney) and were more likely to have steatosis (69.2%vs 11.8%). No significant difference was found in the expression of genes involved in lipogenesis or transport in patients infected with HBV or HCV of either genotype. Contrary to expectation, given the greater degree of steatosis in HCVGT3-infected liver, expression of enzymes involved in lipogenesis was not elevated in HCVGT3 compared with HCVGT1 or HBV-infected liver. Significantly less mRNA for SREBF1 was found in HCVGT3-infected liver tissue compared with HCVGT1-infected liver (1.00 ± 0.06 vs 0.70 ± 0.15 P < 0.05). These results suggest that steatosis in patients infected with HCVGT3 is not the result of a sustained SREBF1 driven increase in expression of genes involved in lipogenesis. In addition, a significant genotype-independent correlation was found between the expression of APOB, MTTP, PRKAA1 and PPARA, indicating that these networks are functional in HCV-infected liver.

In-well degassing issues for measurements of dissolved gases in groundwater

Measurement of dissolved gases in groundwater is becoming increasingly common and important. Many of these measurements involve monitoring or sampling within wells or from water pumped from wells. We used total dissolved gas pressure (TDGP) sensors placed in the screened section of various wells (4 to 72 m deep) to assess the dissolved gas conditions for open wells compared to the conditions when sealed (i.e., isolated from the atmosphere) with a hydraulic packer (one well) or when pumped. When the packer was installed (non-pumping conditions), TDGP rose from <1.7 to >3.1 atm (<172 to >314 kPa), with declines noted when the packer was removed or deflated. While pumping, TDGP measured in many of the wells rose to substantially higher levels, up to 4.0 atm (408 kPa) in one case. Thus, when groundwater is gas charged, the background aquifer TDGP, and likewise the dissolved gas concentrations, may be substantially higher than initially measured in open wells, indicating significant in-well degassing. This raises concerns about past and current methods of measuring the dissolved gases in groundwater. Additional procedures that may be required to obtain representative measurements from wells include (1) installing in-well hydraulic packers to seal the well, or (2) pumping to bring in fresh groundwater. However, observed transient decreased TDGPs during pumping, believed to result from gas bubble formation induced by drawdown in the well below a critical pressure (relative to TDGP), may disrupt the measurements made during or after pumping. Thus, monitoring TDGP while pumping gas-charged wells is recommended.

Separation of physical loading from photosynthesis/respiration processes in rivers by mass balance

Diurnal variations in physical and chemical concentrations, including nutrients, are observed in river ecosystems. Understanding these cycles and separating the effects of physical loading (from point and non-point sources) and biogeochemical processes are necessary for water management and the TMDL process. A chloride mass balance approach is used to separate the relative influences of physical loading and biogeochemical processes in the Bow River through Calgary, Canada, which has a significant influence on the river water chemistry. Sampling campaigns were conducted in December 2005, when minimal photosynthesis and respiration occur, and in July 2006, when river discharge is high and some photosynthesis and respiration activity is present. Samples in each campaign were collected at point source input and output along the river reach through the city every hour for a 24-hour period, allowing for time of travel. The two wastewater treatment facilities within the city contributed the majority of physical mass loading to the river, with temporal variations in effluent discharge, chloride, and nutrient concentrations. Wastewater effluent chloride to nutrient (as well as other parameter relationships) concentrations also varied diurnally. An hourly chloride mass balance was achieved, within 0.5% (average, S.D.=4.4) for December and 7.7% (average, S.D.=4.2) for July, between estimated cumulative sum values from all inputs and measured values at the river output downgradient of the city, allowing for the investigation of other parameter conservativeness. Some slight diurnal variations associated with photosynthesis and respiration were observed even with limited productivity in the river. Nitrate mass fluxes appeared to be most strongly influenced by photosynthesis and respiration processes, with phosphate being less influenced. Ammonia mass fluxes appeared to be most strongly influenced by wastewater effluent loading. Physical loading can mask or enhance biogeochemical diurnal fluctuations, creating errors in river process interpretations. Chloride was a useful tracer in the mass balance to distinguish between and assist in separating physical loading and biogeochemical processes in the river.

Abnormal development of glomerular endothelial and mesangial cells in mice with targeted disruption of the lama3 gene

Mice with targeted disruption of the lama3 gene, which encodes the alpha3 chain of laminin-5 (alpha3beta3gamma2, 332), develop a blistering skin disease similar to junctional epidermolysis bullosa in humans. These animals also develop abnormalities in glomerulogenesis. In both wild-type and mutant animals (lama3(-/-)), podocytes secrete glomerular basement membrane and develop foot processes. Endothelial cells migrate into this scaffolding and secrete a layer of basement membrane that fuses with the one formed by the podocyte. In lama3(-/-) animals, glomerular maturation arrests at this stage. Endothelial cells do not attenuate, develop fenestrae, or form typical lumens, and mesangial cells (MCs) were not identified. LN alpha3 subunit (LAMA3) protein was identified in the basement membrane adjacent to glomerular endothelial cells (GEnCs) in normal rats and mice. In developing rat glomeruli, the LAMA3 subunit was first detectable in the early capillary loop stage, which corresponds to the stage at which maturation arrest was observed in the mutant mice. Lama3 mRNA and protein were identified in isolated rat and mouse glomeruli and cultured rat GEnCs, but not MC. These data document expression of LAMA3 in glomeruli and support a critical role for it in GEnC differentiation. Furthermore, LAMA3 chain expression and/or another product of endothelial cells are required for MC migration into the developing glomerulus.

Evolution of novel functions: cryptocyanin helps build new exoskeleton in Cancer magister

Hemocyanin, the blue blood protein of many arthropods and molluscs, reversibly binds oxygen at its highly conserved copper-oxygen-binding sites and supplies tissues with oxygen. Cryptocyanin, closely related structurally and phylogenetically to arthropod hemocyanin, lacks several of the six critical copper-binding histidines, however, and has lost the ability to bind oxygen. Despite this loss of function, cryptocyanin continues to be synthesized, an indication that it has been exploited to carry out new functions. Here, we show that cryptocyanin is present in extremely high concentrations in the hemolymph of the crab during the premolt portion of the molt cycle. Both proteins are specifically expressed in the same type of cell in the hepatopancreas and secreted into the hemolymph, but cryptocyanin plays a major role in forming the new exoskeleton, while hemocyanin functions in oxygen transport. A cessation in cryptocyanin, but not hemocyanin, synthesis after eyestalk ablation supports our hypothesis that cryptocyanin is closely regulated by molting hormones. The contrasts between the two gene products illustrate how a gene duplication of a copper-oxygen protein and its subsequent mutation may work in concert with the evolution of new regulatory mechanisms, leading to the assumption of new functions.

Changes in ground water quality in an irrigated area of southern Alberta

Few studies have documented spatial and temporal variations in ground water quality in areas with high densities of animal farming operations (AFOs), or the long-term effects on surface-water quality. Changes in ground water quality were characterized in an irrigated area with a high density of AFOs in southern Alberta, Canada to evaluate the effect on ground water quality of manure application to fields. Fifty-five piezometers in the oxidized zone were sampled once or twice annually from 1995 to 2001, and temporal changes were analyzed using mixed model analysis. Average NO3- -N increased significantly from 12.5 to 17.4 mg L(-1) and average Cl- increased significantly from 19.4 to 34.4 mg L(-1) in piezometers installed in an unconfined sand aquifer at locations receiving fertilizer and manure. Compared with these manured locations, nitrate and chloride concentrations were significantly lower in shallow aquifer water in areas of pasture or native range, and concentrations did not change significantly with time. Nitrate and chloride concentrations in shallow ground water in fine-textured manured locations did not change significantly. Ground water below about 6 m in till and fine lacustrine sediments contains 18O signatures indicative of recharge under preirrigation or glacially influenced conditions, suggesting this ground water has a low vulnerability to agricultural contamination. Evaluations suggest that shallow ground water discharge will cause NO3- -N and Cl- in the Oldman River to increase by factors of at least 4.3 and 1.3, respectively, with more significant effects in smaller streams and under low-flow conditions.

Bacterial water quality in the personal water bottles of elementary students

BACKGROUND

Samples of drinking water were collected directly from the personal water bottles of students at an elementary school in Calgary, Alberta.

METHODS

Total and fecal coliforms and heterotrophic bacteria were enumerated using membrane filtration and agar plate count methods respectively.

RESULTS

The Canadian Drinking Water Quality Guidelines (CWQG) criterion was exceeded for total coliform in 13.3% of 75 samples. Fecal coliform and total heterotrophic criteria were exceeded in 8.9% (of 68 samples) and 64.4% (of 76 samples) respectively.

FINDINGS

The use of personal water bottles for students in elementary classrooms is not recommended.

Bacterial water quality in the personal water bottles of elementary students

BACKGROUND

Samples of drinking water were collected directly from the personal water bottles of students at an elementary school in Calgary, Alberta.

METHODS

Total and fecal coliforms and heterotrophic bacteria were enumerated using membrane filtration and agar plate count methods respectively.

RESULTS

The Canadian Drinking Water Quality Guidelines (CWQG) criterion was exceeded for total coliform in 13.3% of 75 samples. Fecal coliform and total heterotrophic criteria were exceeded in 8.9% (of 68 samples) and 64.4% (of 76 samples) respectively.

FINDINGS

The use of personal water bottles for students in elementary classrooms is not recommended.

Contrasting nitrate adsorption in Andisols of two coffee plantations in Costa Rica

Fertilizer use in coffee plantations is a suspected cause of rising ground water nitrate concentrations in the ground water-dependent Central Valley of Costa Rica. Nitrate adsorption was evaluated beneath two coffee (Coffea arabica L.) plantations in the Central Valley. Previous work at one site had identified unsaturated zone nitrate retardation relative to a tritium tracer. Differences in nitrate adsorption were assessed in cores to 4 m depth in Andisols at this and one other plantation using differences in KCl- and water-extractable nitrate as an index. Significant adsorption was confirmed at the site of the previous tracer test, but not at the second site. Anion exchange capacity, X-ray diffraction data, extractable Al and Si, and soil pH in NaF corroborated that differences in adsorption characteristics were related to subtle differences in clay mineralogy. Soils at the site with significant nitrate adsorption showed an Al-rich allophane clay content compared with a more weathered, Si-rich allophane and halloysite clay mineral content at the site with negligible adsorption. At the site with significant nitrate adsorption, nitrate occupied less than 10% of the total anion adsorption capacity, suggesting that adsorption may provide long-term potential for mitigation or delay of nitrate leaching. Evaluation of nitrate sorption potential of soil at local and landscape scales would be useful in development of nitrogen management practices to reduce nitrate leaching to ground water.

Role of the peripheral myelin protein 22 N-linked glycan in oligomer stability

Peripheral myelin protein 22 (PMP22) is a 22-kDa glycoprotein containing a single N-linked carbohydrate moiety. This posttranslational modification is conserved in PMP22 across species and within members of the PMP22 gene family; however, the function of the oligosaccharide is not known. To study the role of the PMP22 carbohydrate, site-directed mutagenesis was used to alter the glycosylation consensus sequence and produce a glycosylation-deficient mutant protein. This modified PMP22 was expressed in primary Schwann cells (SCs), and the effect of the N-glycan on the turnover rate, oligomerization, and intracellular trafficking of PMP22 was determined. Our data show a slight decrease in turnover rate from a half-life of approximately 70 min for the wild-type (wt) protein to 100 min for the glycosylation mutant. Although the presence of glycosylation-deficient PMP22 oligomers could be detected in SCs, we observed a decrease in oligomer stability compared with the wt oligomers. Both wt and mutant proteins showed similar localization in the endoplasmic reticulum and Golgi compartments and were transported to the SC surface. These results suggest that the N-glycan of PMP22 facilitates, in part, the stability of the PMP22 oligomer; however, the implications of PMP22 oligomerization remain unknown.

Deposition of laminin 5 in epidermal wounds regulates integrin signaling and adhesion

Adhesion of keratinocytes in a wound outgrowth to laminin 5 in the basement membrane via integrins alpha6beta4 and alpha3beta1 is distinct from adhesion to dermal collagen via alpha2beta1 or to fibronectin via alpha5beta1. Leading cells in the outgrowth are distinguished from following keratinocytes by deposition of laminin 5, failure to communicate via gap junctions and sensitivity to toxin B, an inhibitor of RhoGTPase. Laminin 5 deposited by leading keratinocytes onto dermal collagen dominates over dermal ligands and changes the cell signals required for adhesion from collagen-dependent to laminin-5-dependent. Thus, deposition of laminin 5 can instruct keratinocytes to switch from an activated phenotype to a quiescent and integrated epithelial phenotype.

Galanin-R1 and -R2 receptor mRNA expression during the development of rat brain suggests differential subtype involvement in synaptic transmission and plasticity

The present study employed 35S-labelled oligonucleotides and in situ hybridization to examine the distribution in the developing rat brain of mRNA encoding two galanin receptor subtypes, i.e. Gal-R1 and Gal-R2. Gal-R1 and/or Gal-R2 mRNA was detected at embryonic day (E) 20 and from postnatal day (P) 0-70. Gal-R1 mRNA was highly expressed in olfactory regions, ventral hippocampal CA fields, dorsomedial thalamic areas and many hypothalamic nuclei at all ages studied. In adult brain, Gal-R2 mRNA was most abundant in the dentate gyrus, anterior and posterior hypothalamus, raphe and spinal trigeminal nuclei, and in the dorsal motor nucleus of the vagus. At P0-P7, Gal-R2 mRNA was more widely distributed and abundant than at other ages, with highest levels of expression detected throughout the neocortex and thalamus. Thus, Gal-R2 transcripts had a more restricted distribution than Gal-R1 and were differentially abundant at different ages, while the distribution and relative abundance of Gal-R1 mRNA did not alter substantially during postnatal development. In general, Gal-R1 and -R2 mRNAs were localized in regions previously shown to contain [125I]-galanin binding sites and galanin-positive terminals in adult brain. Galanin-immunostaining was assessed in postnatal brain to determine whether peptide innervation correlated with observed transient receptor expression, but was not particularly enriched in Gal-R2 mRNA-positive areas of P4 or P7 brain. These results, together with earlier findings [e.g. Burazin, T. C. D. & Gundlach, A. L. (1998) J. Neurochem., 71, 879-882], suggest that Gal-R1 receptors have a broad role in normal synaptic transmission, while Gal-R2 receptors, in addition to a similar role in particular pathways, may be involved in processes prominent during the establishment and maturation of synaptic connections in developing brain and during neural damage and repair in the mature nervous system.

PMP22 accumulation in aggresomes: implications for CMT1A pathology

Peripheral myelin protein 22 (PMP22) is a 22-kDa glycoprotein mainly expressed by Schwann cells (SCs). Duplication or deletion of the PMP22 gene locus is associated with heritable peripheral neuropathies suggesting that the correct level of PMP22 protein is essential for SC functioning. Previously we reported that in SCs the majority (80%) of newly synthesized PMP22 is rapidly degraded, possibly due to inefficient folding. Here we show that inhibition of the proteasome pathway results in a marked accumulation of PMP22 in the perinuclear cytoplasm. Double immunolabeling with an anti-ubiquitin antibody and various organelle markers indicates that the accumulated PMP22 is found in unique intracellular inclusions, called aggresomes. Moreover, overexpression of PMP22 in SCs can induce perinuclear accumulation of the protein. Together, these studies suggest that the proteasome pathway is critical for the regulation of PMP22 protein levels and raise the possibility that aggresomes may be involved in the pathogenesis of PMP22-associated peripheral neuropathies.

Targeted disruption of the LAMA3 gene in mice reveals abnormalities in survival and late stage differentiation of epithelial cells

Laminin 5 regulates anchorage and motility of epithelial cells through integrins alpha6beta4 and alpha3beta1, respectively. We used targeted disruption of the LAMA3 gene, which encodes the alpha3 subunit of laminin 5 and other isoforms, to examine developmental functions that are regulated by adhesion to the basement membrane (BM). In homozygous null animals, profound epithelial abnormalities were detected that resulted in neonatal lethality, consistent with removal of all alpha3-laminin isoforms from epithelial BMs. Alterations in three different cellular functions were identified. First, using a novel tissue adhesion assay, we found that the mutant BM could not induce stable adhesion by integrin alpha6beta4, consistent with the presence of junctional blisters and abnormal hemidesmosomes. In the absence of laminin 5 function, we were able to detect a new ligand for integrin alpha3beta1 in the epidermal BM, suggesting that basal keratinocytes can utilize integrin alpha3beta1 to interact with an alternative ligand. Second, we identified a survival defect in mutant epithelial cells that could be rescued by exogenous laminin 5, collagen, or an antibody against integrin alpha6beta4, suggesting that signaling through beta1 or beta4 integrins is sufficient for survival. Third, we detected abnormalities in ameloblast differentiation in developing mutant incisors indicating that events downstream of adhesion are affected in mutant animals. These results indicate that laminin 5 has an important role in regulating tissue organization, gene expression, and survival of epithelium.

Molecular analysis of the human laminin alpha3a chain gene (LAMA3a): a strategy for mutation identification and DNA-based prenatal diagnosis in Herlitz junctional epidermolysis bullosa

Mutations in the genes (LAMA3, LAMB3, and LAMC2) encoding the subunit polypeptides of the cutaneous basement membrane zone protein laminin 5 have been reported in different forms of junctional epidermolysis bullosa (JEB), an inherited blistering skin disease. In this study, we present the complete exon-intron organization of the "a" transcript of the laminin alpha3 chain gene, LAMA3a, which is expressed primarily in the skin. We have performed fine-resolution mapping of this gene on chromosome 18q11.2 using a human-hamster radiation hybrid panel. We have also developed a mutation-detection strategy based on the exon-intron structure of LAMA3a. This strategy, based on PCR amplification of genomic sequences, followed by heteroduplex scanning and automated nucleotide sequencing, was used for successful mutation screening in a family with the lethal (Herlitz) type of JEB, and two novel LAMA3 mutations were identified in the proband. The mutations consisted of a single-base pair deletion in LAMA3a exon A11 on the paternal allele, designated 1239delC, and a two-base pair deletion in LAMA3a exon A23 on the maternal allele, designated 2959delGG. This information was also used for DNA-based prenatal testing in a subsequent pregnancy in this family. Collectively, these results attest to our expanding capability to elucidate the genetic basis of various forms of epidermolysis bullosa using molecular techniques.

The relationship between loneliness, social support, and decline in cognitive function in the hospitalized elderly

To determine the effects of preexisting levels of loneliness and social support on cognitive decline during hospitalization, 145 elderly subjects 65 to 92 years old without impaired cognition were tested for levels of loneliness, social support, and cognitive status on admission to an acute care hospital. Five days later, cognitive status was again measured in the remaining 86 patients. Loneliness was found to be inversely related to cognitive status on admission. In those with high loneliness scores on admission, cognitive status had improved significantly 5 days later. High social support was correlated with high cognitive status on admission and significant cognitive decline during hospitalization.

Ontogenic expression of natriuretic peptide mRNAs in postnatal rat brain: implications for development?

The central natriuretic peptide system is composed of at least three structurally homologous and uniquely distributed peptides and receptors which are thought to be involved in the central regulation of cardiovascular and autonomic function and more recently been shown to affect cellular growth and proliferation, processes pertinent to mammalian development. As such, following our initial mapping of preproatrial natriuretic peptide (ppANP) mRNA in adult brain [M.C. Ryan, A.L. Gundlach, Anatomical localization of preproatrial natriuretic peptide mRNA in the rat brain by in situ hybridization histochemistry: in olfactory regions, J. Comp. Neurol., 356 (1995) 168-182], it was of interest to determine the ontogenic expression of natriuretic peptide mRNAs in the developing rat brain. Using in situ hybridization histochemistry of specific [35S]- or [33P]-labeled oligonucleotides, ppANP and preproC-type natriuretic peptide (ppCNP) mRNAs were detected in the developing rat brain from postnatal day 4 to day 60 (adult). PpANP mRNA was observed in many hindbrain, but only some forebrain, regions at postnatal day 4. Regional differences in the temporal expression of ppANP mRNA were apparent with ppANP mRNA detected in the medial preoptic area, mammillary nuclei and medial habenular nucleus at postnatal day 4 and in other areas including the arcuate and dorsomedial hypothalamic nuclei and in olfactory and limbic regions at postnatal day 10. A number of regions also exhibited transient expression of ppANP mRNA such as the bed nucleus of the stria terminalis and the medial cerebellar nucleus. In contrast, ppCNP mRNA was detected at relatively high levels in several regions on postnatal day 4 including olfactory nuclei, the hippocampus and particularly the pontine nucleus. The level of expression appeared to increase markedly in most regions including forebrain olfactory and hippocampal areas and in brainstem regions including the pontine nucleus, the parvocellular and lateral reticular and spinal trigeminal nuclei by postnatal days 10 and 13, but decreased from this peak to equivalent to adult levels by postnatal day 28. The differential and transient expression of the natriuretic peptides during postnatal development, together with previous reports of the ontogenic regulation of natriuretic peptide receptor expression and binding patterns, further suggests their involvement in developmental processes in the rat CNS and provides information relevant to the likely functional development of natriuretic peptide-utilizing pathways.

Galanin messenger RNA during postnatal development of the rat brain: expression patterns in Purkinje cells differentiate anterior and posterior lobes of cerebellum

Following our initial mapping of preprogalanin messenger RNA in adult brain and its presence in a subpopulation of cerebellar Purkinje neurons [Ryan M. C. and Gundlach A. C. (1996) Neuroscience 70, 709-728], the present study examined the ontogenic expression of preprogalanin messenger RNA in the postnatal rat brain focussing on the Purkinje cells of the cerebellar cortex. Using in situ hybridization histochemistry, preprogalanin messenger RNA was detected in the developing forebrain and hindbrain from postnatal day 4 to day 60 (adult). On postnatal day 4 very light hybridization signal (labelling) was observed in cells of a number of nuclei including the central amygdaloid nucleus, the medial preoptic area, paraventricular nucleus and dorsomedial hypothalamic nucleus of the forebrain while lightly-labelled cells were detected in neurons of the nucleus of the solitary tract and locus coeruleus of the hindbrain. Hybridization signal was not apparent in other nuclei until later, with positively-labelled neurons first apparent in the dorsal cochlear nucleus at postnatal day 21. The abundance of preprogalanin messenger RNA-positive neurons and the intensity of the hybridization signal increased, in most regions, until postnatal day 28 when labelling resembled that of the mature rat. Preprogalanin messenger RNA was first detected in the cerebellum on postnatal day 10 only in Purkinje cells of lobule 10 of the posterior vermis and increased in distribution throughout Purkinje cell layers of the entire cerebellar cortex by postnatal day 13. The intensity of hybridization signal in Purkinje cells varied between lobules, with Purkinje cells in lobule 10 displaying a moderate to heavy degree of labelling, while lobules 6-9 and the more posterior lobules of the hemisphere including crus 2 of the ansiform lobule, the paramedian lobule and the copula pyramis, displayed only light labelling. The intensity of labelling in the anterior vermis and the remaining lobules of the hemisphere including crus 1 of the ansiform lobule, the simple lobule, the paraflocculus and the flocculus, was homogeneously weak. By postnatal day 21, Purkinje cell labelling reached maximum intensity in all lobules. Regional differences were still apparent, however, with labelling in the posterior vermis and hemisphere ranging from moderate to heavy, with only light to moderate labelling detected in the anterior vermis. The intensity of labelling in the posterior vermis and most lobules of the hemisphere was similar from postnatal day 21 to adulthood, while, in the anterior vermis, crus 1 of the ansiform lobule and the simple lobule, the intensity of hybridization decreased slightly by postnatal day 28 and was completely absent in Purkinje cells of the adult rat. Differential expression of preprogalanin messenger RNA in Purkinje cells of the developing rat cerebellum and transient expression in certain lobules suggests that galanin gene products may have a role in both the developing and mature rat brain and that galanin gene expression may represent a useful marker for differentiating the anterior and posterior cerebellar lobes.

Angiotensinogen and natriuretic peptide mRNAs in rat brain: localization and differential regulation by adrenal steroids in hypothalamus

Adrenal steroids have been shown to modulate angiotensin II and natriuretic peptide systems--peptide synthesis and metabolism--in vitro. In the present study the effects of adrenal steroids on mRNA encoding the angiotensin II precursor, angiotensinogen (AOGEN), and the natriuretic peptides, atrial natriuretic peptide (ANP) and C-type natriuretic peptide (CNP) in the rat hypothalamus were investigated using quantitative in situ hybridization histochemistry of [35S]- and [33P]-labeled oligonucleotide probes. Adrenalectomy produced an apparent overall decrease in preproAOGEN (ppAOGEN) mRNA in presumed astrocytes in the anterior hypothalamus with significant decreases (ANOVA) measured in the medial preoptic area, the ventral region of the medical preoptic area, the paraventricular, suprachiasmatic, supraoptic, and periventricular nuclei. ppAOGEN mRNA levels were restored by both glucocorticoid (dexamethasone; 2 micrograms/ml in drinking water) and mineralocorticoid (aldosterone; 50 micrograms/kg, SC) replacement. Treatment of intact animals with dexamethasone (2 micrograms/ml in drinking water for 5 days) and aldosterone (100 micrograms/kg, SC, daily for 10 days) produced a significant increase in ppAOGEN mRNA in those hypothalamic regions affected by adrenalectomy. ppANP and ppCNP mRNA-positive neurons were successfully detected using [35S]- and [33P]-labeled probes, respectively, and were abundant in the anterior hypothalamus, particularly in the anteromedial preoptic nucleus of the medial preoptic area. In contrast to the effects on ppAOGEN mRNA, however, alterations in adrenal steroid levels did not significantly change ppANP or ppCNP mRNA levels in neurons of the anteromedial preoptic nucleus or in the arcuate nucleus. These results indicate that adrenal steroids modulate AOGEN gene transcription in vivo, consistent with previous reports of increased levels of ppAOGEN mRNA in a number of brain regions in response to acute dexamethasone treatment and reports of decreased AOGEN immunoreactivity in brain regions of adrenalectomized rats. In contrast, despite reports of modulation of hypothalamic ANP immunoreactivity following adrenalectomy and dexamethasone treatment, it would appear that adrenal steroids do not alter the transcription or stability of hypothalamic natriuretic peptides mRNA in vivo.

Differential regulation of angiotensinogen and natriuretic peptide mRNAs in rat brain by osmotic stimulation: focus on anterior hypothalamus and supraoptic nucleus

Central angiotensin II and natriuretic peptide systems have been shown to be involved in the central regulation of blood fluid homeostasis with alterations in central peptide and/or receptor levels observed following changes in osmotic status. The present study investigated the effects of sodium loading on mRNA encoding the angiotensin II precursor, angiotensinogen (AOGEN), and the natriuretic peptides, atrial natriuretic peptide (ANP) and C-type natriuretic peptide (CNP) in rat brain using quantitative in situ hybridization histochemistry of [35S]- and [33P]-labeled oligonucleotide probes. Following 7 and 14 days of 2% sodium chloride in drinking water a significant increase was detected in preproAOGEN (ppAOGEN) mRNA in presumed astrocytes in regions of the anterior hypothalamus, including the periventricular nucleus, the medial preoptic area and medial preoptic nucleus, while a decrease was observed in astrocytes in the supraoptic nucleus. Other forebrain regions examined including the subfornical organ, bed nucleus of the stria terminalis and the arcuate nucleus showed no significant alteration in the level of ppAOGEN mRNA. Sodium loading did not appreciably alter ppANP or ppCNP mRNA levels in neurons of the anteromedial preoptic or arcuate nuclei or hippocampus at the times studied. PpANP mRNA levels were also unaltered in Barrington's nucleus following sodium loading, while preprocorticotropin-releasing hormone mRNA was significantly decreased. These results indicate that AOGEN mRNA transcription/stability in vivo is modulated by alterations in osmotic balance, consistent with previous reports of a central role for AII in cardiovascular and body fluid homeostasis. In contrast, despite reports of modulation of hypothalamic ANP-immunoreactivity following changes in osmotic status, it would appear that osmotic stimulation over periods of 7-14 days does not markedly alter the transcription or stability of hypothalamic natriuretic peptide mRNAs in vivo.

The functions of laminins: lessons from in vivo studies

This series of three short reviews is an attempt to summarize our current knowledge of the in vivo tests of hypotheses of laminin functions. The structures of the laminins have been thoroughly reviewed recently (P. Ekblom and R. Timpl, in press), and I will not attempt to repeat this information here. Instead, I will focus on the recent evidence gathered from gene knock out experiments in mice and from naturally occurring human and mouse gene mutations. The most obvious lesson from the above studies--other than demonstrating the importance of laminins in general--is that the structural diversity of the laminin family members makes highly specialized functions possible. While all laminins may share many functional properties, the individual chains are involved in interactions which cannot be substituted for by other laminins or by other basement membrane components. While this concept is not new, it is very satisfying to see its validity so dramatically confirmed. It is therefore predictable that additional gene ablation experiments using other known and yet undescribed laminin genes will be equally interesting and informative. To me, one of the most striking lessons from these studies is how strongly the induced mouse mutations mimic human disease. With all the concerns with genetic background differences and species specific effects, manipulation of the laminin genes appears to be a particularly good first approach to identifying the causes of human disease. There is an abundant literature accumulated from biochemical and, more recently, molecular structural analyses, and from in vitro systems, suggesting a role of laminins contributing directly to the stability of the basement membrane. There is an equally vast literature supporting an indirect role in mediating cellular behavior, through interactions with various receptors. It is interesting that the in vivo studies summarized above support both activities. In the case of laminin 5 mutations, the phenotypic consequence appears to be due primarily to the loss of an important structural link between the epithelial cytokeratins and the dermal anchoring fibrils. The ultrastructure of the epithelium appears normal, as does the architecture of the papillary dermis. Only the anchoring complex itself is aberrant. The absence of laminin 5 appears not to compromise the development or viability of the epidermis. The basement membrane appears normal-other than the anchoring complex itself. The pathology observed in the newborn is believed to be due to the frictional trauma of birth, with the expectation that the function of the fetal skin is normal in utero. The Herlitz epidermolysis bullosa phenotype is obvious immediately at birth, and it does not progress postnatally beyond the extent to which the affected individual experiences additional frictional trauma or secondary consequences such as infection or fluid loss. Since laminin 5 is only one of a series of structural links within the anchoring complex, one would predict that a loss of any of these links would result in the same phenotype. Current evidence supports this view, as the absence of integrin alpha 6 beta 4 (Vidal et al., 1995; Dowling et al., 1996; Georges-Labouesse et al., 1996; van der Neut et al., 1996) or of collagen VII (A. M. Christiano and J. Uitto, in press) also results in dramatic neonatal dermal-epidermal fragility. The differences in phenotype, such as the pyloric atresia in the case of loss of integrin alpha 6 beta 4, are presumably due to additional functions of the integrin in other tissues or in other developmental processes. Therefore, the laminin 5 mutations may be unique, in that the in vivo studies suggest that the primary role of the molecule is in the elaboration and stability of the anchoring complex, but not in the basement membrane itself. Of course, since the in vivo phenotype reflects only losses that cannot be compensated, this interpretation may be much too narrow. (ABSTRACT TRUNCATED)

Structure-activity relationships of competitive NMDA receptor antagonists

The interaction of structurally constrained competitive NMDA receptor antagonists, (+/-)-cis-4-phosphonomethyl-2-piperidine carboxylic acid (CGS 19755), (2-amino-4,5-(1,2-cyclohexyl))-7-phosphonoheptanoic acid (NPC 12626), (+/-)-6-phosphonomethyl-de-cahydroisoquinoline-3-carboxylic acid (LY 274614), (S)-alpha-amino-5-phosphonomethyl[1,1'-biphenyl]-3-propanoic acid (SDZ EAB-515) and (S)-alpha-amino-5-phosphonomethyl[1,1':4',1"-terphenyl]-3-propa noi c acid (SDZ 215-439), with their receptor was assessed using radioligand binding, protection against neurotoxicity in cortical neuronal cultures and computerised molecular modelling. All compounds inhibited the specific binding of [3H]CGS 19755 and/or [3H]CGP 39653 (inhibition constants 40-2000 nM), and protected neuronal cultures from NMDA-mediated injury (IC50 values 1.3-5.6 microM). Quantitative conformational analyses indicated that the molecules fitted well to a NMDA receptor model. Our results draw attention to a deep hydrophobic pocket, defined by the bi- and terphenyl containing antagonists (SDZ EAB-515, SDZ 215-439), which may influence potency and selectivity.

Helping home care aides work with newly dependent elderly in a cluster care setting

A Cluster Care Aide Model of home care was implemented within a senior apartment complex in New York City. Many unforeseen difficulties arose when traditional home health aides were teamed with newly dependent elderly. Cooperation between the administrators of the two agencies created a specialized orientation and in-service program with positive outcomes.

Loneliness, social support and depression as interactive variables with cognitive status: testing Roy's model

This study examined the relationships between and among the variables of loneliness, social support, depression, and cognitive functioning in adults over 60, living in senior housing in a metropolitan area. Other variables, namely, life-satisfaction and ability to perform activities of daily living, were also measured. Although the research hypotheses were not supported, relationships between subjects' health status, life satisfaction, and self-assessment of health were significant. Assessment of these variables by community and advanced practice nurses who work with community elderly, to effect positive client outcomes, is presented within the context of Roy's adaptation model.

Localization of preprogalanin messenger RNA in rat brain: identification of transcripts in a subpopulation of cerebellar Purkinje cells

Galanin, a 29 amino acid peptide, is widely distributed throughout both the peripheral and central nervous systems and is thought to be involved in multiple physiological functions including smooth muscle relaxation, stimulation of feeding, blood pressure regulation, control of hormone secretion and modulation of nociception. Galanin has been shown to co-exist with several neurotransmitters throughout the neuroaxis and in some cases to modify their presynaptic and postsynaptic actions. In the present study, the anatomical distribution of preprogalanin messenger RNA in rat brain was examined by in situ hybridization histochemistry using specific 35S-labelled oligonucleotide probes. Neurons expressing preprogalanin messenger RNA were found throughout the brain and were particularly abundant in the hypothalamus. High densities of preprogalanin messenger RNA-positive neurons were found in the anteroventral preoptic, supraoptic, paraventricular and dorsomedial nuclei of the hypothalamus, in the locus coeruleus and in the nucleus of the solitary tract. Moderate densities of preprogalanin messenger RNA-positive cells were apparent in the periventricular and arcuate nuclei of the hypothalamus, in the dorsal raphe and dorsal cochlear nuclei. Low densities of preprogalanin messenger RNA-expressing neurons were observed in the piriform cortex, medial septum and the retrochiasmatic area. These findings are consistent with results of previous in situ localization studies of preprogalanin messenger RNA and also with studies reporting the distribution of galanin-like immunoreactivity in rat brain. A novel finding, however, was the detection of preprogalanin messenger RNA in Purkinje cells in the caudal cerebellar vermis (lobules 6 to 10) and the flocculus and paraflocculus of the lateral hemispheres of the cerebellum. Galanin is presumably co-localized in these cells with GABA, which is normally present in Purkinje cells and possibly with tyrosine hydroxylase, which has recently been detected in a similar subpopulation of cerebellar Purkinje cells in both rat and mouse. Thus, the present study reveals a previously unreported site of galanin gene expression in the cerebellum which represents a novel, putative site of action for galanin to add to its already varied physiological roles.

Anatomical localisation of preproatrial natriuretic peptide mRNA in the rat brain by in situ hybridisation histochemistry: novel identification in olfactory regions

Atrial natriuretic peptide (ANP) is one of three structurally homologous natriuretic peptides present in heart and brain, which is thought to be involved in the regulation of water and salt intake, blood pressure, and hormone secretion. In the present study, the distribution of preproatrial natriuretic peptide (ppANP) mRNA in the central nervous system of the rat was examined by in situ hybridisation histochemistry by using [35S]-labelled oligonucleotides. Cells expressing ppANP mRNA were apparent in several major neuronal systems, being present in hypothalamic, limbic, pontine and forebrain olfactory regions. Relatively high densities of ppANP mRNA-positive neurones were found in the anterior medial preoptic hypothalamic nucleus, medial habenular nucleus, and in Barrington's nucleus in the pons. Moderate numbers of ppANP mRNA-positive cells were present in a number of amygdaloid nuclei, including the posterolateral and anterior cortical nuclei, in the zona incerta, and the pedunculopontine tegmental nucleus. Other areas, including the ventromedial hypothalamic nucleus and the laterodorsal tegmental nucleus, displayed only low densities of ppANP mRNA-positive neurones. A number of structures in which ppANP mRNA (or ANP-like immunoreactivity) has not previously been reported were found to contain moderate to high numbers of ppANP mRNA-positive neurones including several nuclei associated with the olfactory system, such as the anterior olfactory nucleus and neurones of the tenia tecta and ventrolateral orbital cortex. Although ppANP mRNA in CA1 pyramidal cells of the hippocampus has been described, we also detected labelling in CA2 and ventral CA3 regions of the hippocampus. Conversely, nuclei such as the bed nucleus of the stria terminalis and the nucleus of the solitary tract, which are reported to possess ANP-like immunoreactivity, were found not to contain ppANP mRNA. Overall, these results demonstrate the presence of ANP gene expression in discrete neuronal populations of the rat central nervous system and provide additional evidence to support a putative role for this peptide in regulating and integrating hypothalamic, olfactory, limbic, and neuroendocrine systems.

Junctional epidermolysis bullosis: defects in expression of epiligrin/nicein/kalinin and integrin beta 4 that inhibit hemidesmosome formation

Junctional epidermolysis bullosis (JEB) is a heterogeneous inherited blistering disorder of human epithelial basement membranes (BMs). Characteristically, the epidermis detaches from the BM between the basal cells and the lamina lucida due to reduced numbers of hemidesmosomes (HDs). Attempts to identify a candidate gene for JEB led to the characterization of nicein, a protein complex in normal BMs that is absent from BMs of patients with JEB gravis. In independent research, two related BM glycoproteins, epiligrin and kalinin, were identified as functional adhesion components of HDs. Epiligrin was characterized as a BM ligand for basal cell adhesion via integrins alpha 3 beta 1 in focal adhesions and alpha 6 beta 4 in HDs. Kalinin was characterized as an adhesive ligand and a component of anchoring filaments. Recent antibody and sequence studies on epiligrin/nicein/kalinin have identified limited homologies with laminin. Ongoing studies in multiple laboratories seek to identify mutations in one or more of the three subunits of epiligrin that are causal in JEB gravis. Consistent with the genetic heterogeneity of JEB, we have identified a patient with a variant form of JEB that is associated with pyloric atresia. This patient has negligible HDs, normal epiligrin, but reduced expression of integrin beta 4. A defect in the beta 4 expression may define a subset of JEB cases that also present with pyloric atresia. These results testify to the dual requirements for epiligrin in the BM and integrin beta 4 in the plasma membrane in regulating function of HDs in epithelium.

Heterocyclic amino alcohols related to ifenprodil as sigma receptor ligands: binding and conformational analyses

The interaction of a novel series of heterocyclic amino alcohols with the sigma receptor site was assessed using radioligand binding and computerized molecular modelling. All heterocyclic amino alcohols, like the structurally related ifenprodil, fully inhibited the specific binding of [3H]R(+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine ([3H]3-PPP) to rat cerebral cortical membranes. All compounds recognised two populations of binding sites labelled by [3H]3-PPP and the proportion of sites in the high affinity state was 60-80% of the total sites. Some of the heterocyclic amino alcohols also displayed similar affinity for alpha 1-adrenoceptors labelled by [3H]prazosin, where the pattern of inhibition appears to be stereospecific, unlike that seen with the binding of [3H]3-PPP. The amino alcohols had negligible affinity for sites labelled by the N-methyl-D-aspartate channel ligand, [3H]-(N-1-[thienyl]cyclohexyl)piperidine. Quantitative conformational analyses indicated that the heterocyclic amino alcohols and ifenprodil fitted well to a sigma receptor site model; low energy conformers could be superimposed like other potent sigma receptor ligands with confidence to the sigma receptor model. Our results define a new class of sigma receptor ligands and extend the understanding of the molecular requirements for drugs active at the sigma receptor.

Cloning of the LamA3 gene encoding the alpha 3 chain of the adhesive ligand epiligrin. Expression in wound repair

We have isolated cDNA clones encoding the entire 170-kDa chain of epiligrin (alpha 3Ep) and a genomic clone encoding the alpha 3Ep gene (LamA3). Analysis of multiple cDNA clones revealed two distinct transcripts (alpha 3EpA and alpha 3EpB). Sequencing of the alpha 3EpA transcript indicated sequence and structural homology to laminin alpha 1 and alpha 2 chains that extend from domain IIIa through the carboxyl-terminal G domain. The alpha 3EpB transcript encodes a larger amino-terminal domain and contains additional epidermal growth factor repeats and sequences corresponding to domain IV of alpha 1 laminin. Fluorescence in situ hybridization indicated that the LamA3 gene is located on chromosome 18q11.2, a locus distinct from the LamA1 gene (18p11.3). The G domain of the epiligrin alpha 3 chain contains five subdomains that are individually related to the G subdomains reported for Drosophila and vertebrate laminin alpha chains. Sequence divergence within the G domain of alpha 3 epiligrin suggests that it is functionally distinct from laminin, consistent with our previous report showing that epiligrin interacts with different integrin adhesion receptors. Analysis of RNA from human foreskin keratinocytes (HFKs) identified multiple epiligrin transcripts that were down-regulated by viral transformation and differentiation. In contrast, epiligrin expression was up-regulated in wound sites of human skin.

Fibroblast stimulation of breast cancer cell growth in a serum-free system

Conditioned media from 14 short term fibroblast cell lines were mitogenic for human breast cancer cells with different steroid receptor profiles in serum-free culture. Fibroblast-conditioned medium stimulated tritiated thymidine incorporation in short term culture and growth in a longer proliferation study as measured by the MTT colorimetric assay. Conditioned media from benign and malignant epithelial cells were non-stimulatory for breast cancer cells but that derived from endothelial cells showed similar stimulation to fibroblasts. Partial purification of fibroblast-conditioned medium identified a peptide with a molecular weight of approximately 8 kDa that showed no affinity for heparin and was mitogenic for MCF-7 breast cancer cells.

Is 24-hour operating room staff absolutely necessary for level II trauma center designation?

Recent papers from established trauma centers reported average elapsed times from emergency department (ED) admission to the operating room (OR) of greater than 100 minutes for patients judged to be in immediate need of surgery. This study was undertaken to determine whether patients treated at an institution desiring level II trauma center designation in a geographic area with a low incidence of penetrating trauma suffered any adverse effects because of lack of a 24-hour in-house OR staff. Trauma registry data at The Stamford Hospital, a suburban community teaching hospital without OR nursing staff in-house at night, were reviewed and compared with data from three affiliated level I trauma centers and with established national standards using TRISS methodology. Of 659 major trauma patients, 86 (44 blunt, 42 penetrating) underwent surgery within 12 hours of admission. Patients' injuries were similar in severity to those seen at the affiliated trauma centers and to the Major Trauma Outcome Study population. Mortality rates were also similar. No statistically significant differences were seen in elapsed times from ED arrival to OR arrival even in the subgroup of patients with systolic blood pressure values of < or = 90 mm Hg. No unexpected adverse outcomes could be ascribed to the lack of 24-hour OR staffing in this setting. The estimated cost of providing additional OR staffing is $145,000 per year. Since times to the OR and outcomes were similar to those at level I centers, this expense may not be warranted.

Epiligrin, a new cell adhesion ligand for integrin alpha 3 beta 1 in epithelial basement membranes

Epiligrin is a new glycoprotein in most epithelial basement membranes (BMs) and is a ligand for cell adhesion via integrin alpha 3 beta 1. In the extracellular matrix of human foreskin keratinocytes (HFKs), epiligrin contains three disulfide-bonded, glycoprotein subunits, E170, E145, and E135, based on molecular size in kilodaltons. Epiligrin, immunopurified with MAb P1E1, induced cell adhesion and localization of integrin alpha 3 beta 1 in focal adhesions (FAs). Cell adhesion to epiligrin was inhibited with an anti-alpha 3 beta 1 MAb. Epiligrin also colocalized with integrin alpha 6 beta 4 in hemidesmosome-like stable anchoring contacts (SACs). alpha 3 beta 1-FAs encircled alpha 6 beta 4-SACs in a complex adhesion structure. alpha 3 beta 1 and epiligrin localized in BM junctions of epithelial cells primarily in organs of endodermal/ectodermal origin. In epidermis, epiligrin was detected in the lamina lucida of BMs. alpha 3 beta 1 localized in plasma membranes of basal cells in contact with epiligrin and also in lateral/apical membranes. Epiligrin is the ligand of an adhesion super complex composed of alpha 3 beta 1-FAs and alpha 6 beta 4-SACs (hemidesmosomes).

The human type II procollagen gene: identification of an additional protein-coding domain and location of potential regulatory sequences in the promoter and first intron

The complete DNA sequence (6 kb) of the 5' portion of the human type II procollagen gene (COL2A1) was determined from the promoter through the third exon including intron sequences and 690 bp of 5' flanking sequence. Three regions between -501 and -649 in the human promoter share high sequence homology to the rat type II procollagen gene and suggest that the functional sequences within the promoter may extend to at least 649 bp upstream from the start site of transcription. The first intron of the human gene contains elements known to play a role in transcription of other genes: three GC boxes, an inverted repeat with homology to a serum responsive element, a viral core enhancer motif, a high-affinity recognition sequence for nuclear factor-1, and an alternating purine/pyrimidine stretch composed of GT repeats. Both the promoter and a portion of the first intron have a high percentage of G + C residues and a high frequency of CpG dinucleotides. In addition, a protein domain that has been identified in the human COL2A1 gene is present in pro-alpha 1(I) and pro-alpha 1(III) collagen but was not previously described for pro-alpha 1(II) collagen. On the basis of this new information we present a modified gene structure for the exons encoding the pro-alpha 1(II) collagen NH2-propeptide.

What does it mean? Making sense of the hospital experience

The process by which people attempt to make sense of an event, such as hospitalization, is referred to as "meaning making" by Kegan. Because the ways in which the elderly define their feelings generated by illness and hospitalization influence their behavioral responses, understanding this interpretation increases the predictions that can be made about their behaviors. Interventions aim at helping clients integrate their experience of illness to form a new self. The nurse acts as the matrix from which patients explore the meaning of illness and hospitalization.

Differential expression of a cysteine-rich domain in the amino-terminal propeptide of type II (cartilage) procollagen by alternative splicing of mRNA

Type II collagen, like other fibrillar collagens, is synthesized as a procollagen containing amino (NH2)-and carboxyl (COOH)-terminal extension peptides. Based on cDNA cloning of human (Baldwin, C. T., Reginato, A. M., Smith, C., Jimenez, S. A., and Prockop, D. J. (1989) Biochem. J. 262, 521-528) and rat (Kohno, K., Martin, G. R., and Yamada, Y. (1984) J. Biol. Chem. 259, 13668-13673) type II procollagen, it was concluded that much of the NH2-terminal propeptide seen in pro-alpha 1(I) was missing. Analysis of human genomic clones for type II collagen revealed an additional exon encoding a 69-amino acid cysteine-rich domain in the NH2-terminal propeptide. This exon (exon 2) is expressed in the mRNA population of chondrocytes isolated from human fetal skeleton and notochord, juvenile costal cartilage, and bovine articular cartilage. Oligonucleotide probes spanning specific exon boundaries were used to detect two populations of procollagen mRNA by Northern blot analysis. Amplification of cDNA templates using polymerase chain reaction provided direct evidence for two distinct pro-alpha 1(II) collagen mRNAs. DNA sequence analysis showed that the two mRNAs resulted from the alternative splicing of exon 2. The protein domain encoded by exon 2 is conserved between the fibrillar collagens and two other extracellular matrix proteins, thrombospondin and von Willebrand factor. In fibrillar collagens, this protein domain may play a regulatory role in fibrillogenesis and feedback inhibition of collagen biosynthesis. Consequently, the differential expression of this protein domain could alter the biosynthesis or fibril formation of type II collagen. In addition, the expression of exon 2 may be a marker for a distinct population of chondrocytes.

Treating childhood respiratory illness in developing countries: mist therapy without electricity

We have developed an effective and well-accepted method of providing mist for children with acute respiratory distress. This method can be especially useful in areas of the world where resources are limited.

Changes in peripheral blood cells in mice after injection with benzo(a)pyrene during pregnancy

Pregnant C3H/Anfcum mice were injected ip with 150 micrograms benzo(a)pyrene (BP)/g body weight at the second trimester (12 days). Quantitative and differential changes were assayed in the peripheral blood leukocytes and erythrocytes at various times before and after mating and treatment. Within 5 days after injection, a 2- to 4-fold reduction in leukocytes was observed when compared to controls [corn oil (vehicle for BP)-injected pregnant females] which persisted into the 10th postpartum day. The erythrocytes were also significantly reduced but not to the same degree (1.2- to 1.5-fold). Depression in white blood cells is attributed to lymphocyte depletion since the granulocytes were virtually unchanged and the lymphocyte to granulocyte ratio, ordinarily greater than 2 was 1 or less than one. No change in monocytes was observed and none of the cell populations, including the erythrocytes, appeared to be abnormal (e.g., no increase in reticulocytes). A moderate reduction (1.5-fold) in erythrocytes and leukocytes also occurred in the controls (vs virgin females). Pregnancy also led to transient decreases in medium sized lymphocytes and 3- to 4-fold increase in small lymphocytes shortly after mating to about 3 days before parturition. These results show that, although pregnancy depresses the leukocyte profile, exposure to BP exacerbates this change, and preferentially affects the lymphocytes. These blood profile changes may have important health consequences in the mother and her progeny.