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Biomedical subjects

E Penner

Publications and source records attributed to E Penner.

At least 19 recordsLinked to original sources

The relation of iron status and hemochromatosis gene mutations in patients with chronic hepatitis C.

BACKGROUND & AIMS: Elevated hepatic iron concentration may affect the response to antiviral therapy in chronic hepatitis C. This study explored the contribution of genetic hemochromatosis to iron accumulation in chronic hepatitis C. METHODS: HFE mutations (C282Y and H63D) were assessed in 184 patients with chronic hepatitis C virus and 487 controls. Liver biopsy specimens were available in 149 patients. Hepatic iron content was measured in 114 patients by atom-absorption spectrophotometry. RESULTS: The C282Y and H63D allele frequencies were 7.06 and 11.6 in patients and 4.83 and 11.09 in controls, respectively. Eight patients were homozygotes (5 C282Y [2.7%] and 3 H63D [1.6%]), 2 compound heterozygotes (1%), and 49 heterozygotes (14 C282Y [7.6%] and 35 H63D [19%]). Biochemical evidence of iron overload was more common in patients with HFE mutations (28 of 47) than in those without (34 of 102; P = 0.0045). Histological iron grading and hepatic iron content overlapped among patients with or without mutations. A hepatic iron index of >1.9 was observed only in 1 of the 4 C282Y homozygotes and 1 of the 3 H63D homozygotes. CONCLUSIONS: HFE mutations contribute to but do not fully explain hepatic iron accumulation in chronic hepatitis C. Furthermore, C282Y or H63D homozygosity in chronic hepatitis C is not necessarily associated with a high hepatic iron content.

Adolescent

Characterization of the inflammatory infiltrate in autoimmune cholangitis. A morphological and immunhistochemical study.

Autoimmune cholangitis (AIC) is characterised by clinical and/or laboratory features of cholestasis, the presence of antinuclear antibodies and the lack of antimitochondrial antibodies. Histologically, changes largely identical to those found in primary biliary cirrhosis (PBC) are typically found. It is not possible to differentiate between AIC and PBC on conventional morphological grounds, and we therefore wished to find whether there is a difference between these entities in the composition of the inflammatory infiltrate leading to bile duct destruction. In liver biopsies from ten patients with confirmed AIC and ten patients with PBC the inflammatory infiltrate was characterised with antibodies against CD 3, OPD 4 CD 8, GB 7, L 26, CD 56 and CD 57. In AIC, T cells were predominant in the portal inflammatory infiltrate in nine cases. Granzyme B-positive activated cytolytic T lymphocytes were found in the bile duct epithelium in five cases. All these five cases showed inflammatory bile duct destruction. No significant differences between the immunohistochemical findings in AIC and in PBC were found. We suggest that AIC is a subgroup of PBC, antimitochondrial antibody-negative type.

Adult

Members of the glutathione S-transferase gene family are antigens in autoimmune hepatitis.

BACKGROUND & AIMS: Autoimmmune hepatitis (AIH), a chronic liver disorder, can be classified into two subtypes on the basis of the specificities of circulating autoantibodies. Type I AIH is defined by antibodies to nuclear and/or smooth muscle antigens (SMA), and type II is characterized by antibodies to cytochrome P450IID6. There is an additional type of AIH characterized by antibodies to a cytosolic soluble liver antigen (SLA), which can occur alone or in combination with antinuclear antibodies and SMA. The aim of this study was to identify the reactive antigen in SLA, a heterogenous cytosolic fraction consisting of at least 100 extremely soluble proteins. METHODS: Sera from 31 patients with AIH reacting with SLA and from 30 disease controls were tested. The immunoreactive antigens were determined using immunoprecipitation and immunoblotting after one- and two-dimensional polyacrylamide gel electrophoresis. The antigens were identified by microsequencing of the corresponding protein spots. RESULTS: Twenty-five of 31 anti-SLA-positive sera (80, 7%) reacted with a set of proteins ranging from 25 to 27 kilodaltons that were identified as three subunits of glutathione S-transferases: Ya, Yb1, and Yc. CONCLUSIONS: Glutathione S-transferase subunit proteins represent the major autoantigen in anti-SLA-positive AIH. This new finding permits the establishment of standardized immunoassays for routine diagnosis.

Adolescent

Treatment of pruritus in chronic liver disease with the 5-hydroxytryptamine receptor type 3 antagonist ondansetron: a randomized, placebo-controlled, double-blind cross-over trial.

BACKGROUND: Recently, the serotonin antagonist ondansetron has been reported to have a positive effect on cholestasis-associated pruritus. OBJECTIVES: To study the effect of orally administered ondansetron on pruritus in chronic liver disease in a randomized, placebo-controlled, double-blind, cross-over study. METHODS: Subjective severity of pruritus was assessed using a visual analogue scale (VAS) recorded four times daily by the patients. After a one week pretreatment baseline period the patients were randomized to receive ondansetron tablets 8 mg tds or placebo tablets tds for one week. Following a one week wash-out period patients were switched to the other treatment for one week. The study was ended by an additional follow-up week without medication. For each day peak VAS values were determined and the mean value of the last five days of each week was calculated and referred to as the composite peak VAS score. RESULTS: We observed a significant but moderate reduction of the composite peak VAS score of 1.34 points (CI(95%): 0.12-2.56; P=0.033) during treatment with ondansetron as compared to placebo (treatment effect). In addition, a period effect was observed: a reduction of composite peak VAS score by 1.26 points (C1(95%): 0.04-2.48; P=0.044) was seen in the second treatment period as compared to the first period, irrespective of the kind of treatment. Although under treatment with ondansetron a significant improvement of itching as assessed by the VAS score was demonstrated, this treatment was not preferred over placebo by the patients. CONCLUSIONS: The 5-hydroxytryptamine receptor type 3 antagonist ondansetron has a small, but significant positive effect on pruritus in chronic liver disease as compared to placebo.

Administration, Oral

Rational use of polymerase chain reaction--based detection of viral genomes in patients with serologic markers of hepatitis B or C virus infection.

We studied the value of additional diagnostic information obtained by detection of hepatitis B virus (HBV) DNA or hepatitis C virus (HCV) RNA using the qualitative polymerase chain reaction (PCR) in patients with serologic markers of hepatitis B or hepatitis C virus infection. In HBV infection, all HBsAg+HBeAg+ patients and all HBsAg+HBeAg- patients with alanine aminotransferase (ALT) levels > 100 U/L were positive for HBV-DNA by PCR, whereas in HBsAg+HBeAg- patients with ALT < 100 U/L 58% and in HBsAg+HBeAg- patients with normal aminotransferase 45% were found to be positive. In HBsAg+ patients no further clinically useful information can be obtained by PCR as the presence of HBsAg proves infection. However in three of 42 (7%) patients with markers of past HBV infection (antiHBs and/or antiHBc+) HBV-DNA was detected in the serum. Similarly, in some patients with acute hepatitis B HBV-DNA was demonstrable up to four months after the disappearance of HBsAg from serum, pointing to persistence of viremia despite the loss of serological markers of ongoing HBV infection. Demonstrating ongoing HBV infection in patients with serological markers of past infection is valuable additional information in only selected patients. In HCV infection, 10% of anti-HCV+ patients with increased ALT levels had a negative serum HCV-RNA. However, in 20% of those patients HCV-RNA was demonstrated in a serum sample collected later during follow-up, indicating that a single negative HCV-RNA determination cannot be taken as evidence for the resolution of infection.

Adolescent

Imaging temperature changes in an interventional 0.5 T magnet: in-vitro results.

BACKGROUND AND OBJECTIVE: To evaluate the ability of monitoring laser induced temperature changes in an open, interventional 0.5 T magnet, adopting fast T1-weighted sequences. MATERIALS AND METHODS: A fast gradient echo- (FGRE) and a fast spoiled gradient echo-sequence (FSPGR), both enabling an image update every 2.5 s, were investigated for their ability to visualize laser tissue effects at 5 Watt. Laser induced temperature was fluorooptically measured and correlated with signal intensity (SI) changes depicted by magnetic resonance imaging (MRI). MRI-lesions were compared with macroscopic findings. RESULTS: SI changes on FGRE images appeared as early as 15 s following the onset of laser application and were significantly more pronounced than those seen on FSPGR images (p < .0001). A correlation of r = 0.94 (FGRE) and r = 0.92 (FSPGR) between temperature and SI loss was established. Owing to a steeper slope, the FGRE sequence was considered more sensitive to temperature changes. The areas of macroscopic tissue change correlated with those of SI loss, but lesion size was generally underestimated by MRI. CONCLUSION: Laser monitoring is possible with rapid image updates in a midfield (0.5 T) interventional MRI environment using fast gradient echo sequence designs.

Animals

Target platelet antigens of autoantibodies in patients with primary biliary cirrhosis.

Primary biliary cirrhosis (PBC) is an autoimmune disease of the liver, frequently associated with thrombocytopenia. As various immune abnormalities have been described in PBC, we hypothesized that thrombocytopenia is also an autoimmune phenomenon in these patients. We therefore assessed the frequency of platelet antibodies and their target platelet glycoprotein (GP) specificities. We investigated 66 PBC patients with a median disease duration of 25 months. Twenty-two patients with alcoholic liver disease and thrombocytopenia served as controls. Specificities of platelet antibodies were determined by the monoclonal antibody-specific immobilization of platelet antigens (MAIPA) assay using monoclonal antibodies directed against GPIIb/IIIa and GPIb/IX. The notion that immunoglobulins are nonspecifically bound to platelets was further evaluated by the production of eluates from antibody-coated platelets. The specificities of antibodies in these eluates were again determined by the MAIPA assay. Twenty-six PBC patients had platelet antibodies, whereas antibodies were not detectable in control alcoholic patients. Seven of 13 thrombocytopenic PBC patients had detectable antibodies. Overall, GP Ib/IX and GP IIb/IIIa served in a similar frequency as target antigens. Antibody specificities were confirmed by the production of eluates from platelets. These studies provide evidence that antibodies are specifically bound to platelets in patients with PBC and that the development of immune phenomena in PBC may also involve immuno-mediated platelet destruction.

Adult

Predominance of the HLA-H Cys282Tyr mutation in Austrian patients with genetic haemochromatosis.

BACKGROUND/AIMS: Genetic haemochromatosis is the most common autosomal recessive disorder in Northern European populations. A major histocompatibility complex class I-like gene, HLA-H, has been proposed to be responsible for genetic haemochromatosis. The prevalence of HLA-H gene mutations 282(TGC; Cys/TAC; Tyr) and 63(CAT; His/GAT; Asp) was determined in patients of Austrian origin. METHODS: DNA extracted from the blood of 40 Austrian patients and 271 controls was used to amplify HLA-H gene fragments by the polymerase chain reaction method. The base changes responsible for mutations Cys282Tyr and His63Asp alter recognition sites for restriction enzymes SnaB I and Bcl I, respectively. Digestion products were separated by agarose gel electrophoresis and visualised by ethidium bromide staining. RESULTS: Thirty-one (77.5%) genetic haemochromatosis patients were homozygous for mutation Cys282Tyr and three compound heterozygous for mutations Cys282Tyr and His63Asp. One patient was homozygous for mutation His63Asp but normal for mutation Cys282Tyr. Four patients were normal at both genetic loci and one patient was heterozygous for mutation His63Asp. One control subject homozygous for mutation Cys282Tyr was found on investigation to fulfill diagnostic criteria for haemochromatosis. Eight control subjects homozygous for mutation His63Asp showed no biochemical or clinical evidence of haemochromatosis indicating that this variant is not directly responsible for haemochromatosis. Absence of the Cys282Tyr mutation in six genetic haemochromatosis patients with distinct haplotypes indicates mutations within the HLA-H gene or at alternative genetic loci are the cause of genetic haemochromatosis in these patients. CONCLUSIONS: The HLA-H Cys282Tyr defect is likely to play a key role in the pathogenesis of haemochromatosis in most patients. Predominance of a single HLA-H gene mutation in haemochromatosis allows presymptomatic screening by genotypic analysis.

Adult

Autoantibodies against nucleoporin p62 constitute a novel marker of primary biliary cirrhosis.

BACKGROUND & AIMS: Patients with primary biliary cirrhosis (PBC) frequently produce autoantibodies against constituents of the nuclear envelope. We have recently observed a reactivity of PBC sera with a nuclear envelope antigen at approximately 60 kilodaltons. The aim of this study was to characterize the reactive antigen. METHODS: Sera from 103 patients with liver disease were tested by immunoblotting after the separation of proteins by one- and two-dimensional polyacrylamide gel electrophoresis (PAGE) using proteins of whole nuclei and nuclear pore complexes (NPCs). RESULTS: A nuclear immunofluorescence staining with peripheral accentuation was observed in 25 of 43 sera from patients with PBC. In immunoblotting, the sera displaying a peripheral pattern reacted preferentially with two proteins. Twelve sera showed specificity to an antigen of 210 kilodaltons corresponding to gp210, and 14 sera recognized a protein band at 60 kilodaltons. The intensity of the reactive band at 60 kilodaltons was clearly stronger on blots with immobilized proteins of the NPC than on blots with nuclear proteins, thereby indicating that the sera targeted an antigen as being a component of the NPC. Immunoblotting performed after protein separation by two-dimensional PAGE showed that the sera are directed against nucleoporin p62, a functional protein of the NPC. CONCLUSIONS: Anti-p62 antibodies appear to be a novel marker that is specific for PBC.

Autoantibodies

Nuclear architecture and ultrastructural distribution of poly(ADP-ribosyl)transferase, a multifunctional enzyme.

A monospecific autoimmune serum for poly(ADP-ribosyl)transferase (pADPRT) was used to localise the enzyme in ultrastructural cellular compartments. We detected enzyme in mitochondria of HeLa and Sertoli cells. Within the nucleoplasm the enzyme concentration was positively correlated with the degree of chromatin condensation, with interchromatin spaces being virtually free of pADPRT. During spermatogenesis we observed a gradual increase of the chromatin associated pADPRT that parallelled chromatin condensation. The highest concentration was seen in the late stages of sperm differentiation, indicating the existence of a storage form in transcriptionally inactive nuclei. In nucleoli pADPRT is accumulated in foci within the dense fibrillar component. Such foci are seen in close spatial relationship to sites of nucleolar transcription as revealed by high resolution immunodetection of bromouridine uptake sites. It is suggested that nucleolar pADPRT plays a role in preribosome processing via the modification of nucleolus specific proteins that bind to nascent transcripts and hence indirectly regulates polymerase I activity. The persisting binding of pADPRT to ribonucleoproteins may explain the observed disperse enzyme distribution at lower concentrations in the granular component. The fibrillar centres seem to contain no pADPRT. We conclude that known compounds of fibrillar centres like polymerase I are unlikely candidates for modification via direct covalent ADP-ribosylation.

Animals

[Characterization of inflammatory infiltrates in autoimmune cholangitis: an immunohistochemical study].

Autoimmune cholangitis is clinically characterized by cholestasis and serologically by the presence of antinuclear antibodies (ANA) and a lack of antimitochondrial antibodies (AMA). Morphologic characteristics are non suppurative bile duct destruction (NSBDD), ductopenia and occasionally granulomas. The aim of the study was to characterize the inflammatory infiltrate to find about the possible mechanism of bile duct destruction in AIC. Liver biopsy material of ten patients (9 female/1 male, mean age of 45,5 a) with the clinical and serologic features of AIC were evaluated morphologically for the presence of NSBDD, ductopenia and granulomas. The inflammatory infiltrate was characterized immunohistochemically using Ab against CD3 (pan T lymphocytes), OPD 4 (helper T lymphocytes and memory T lymphocytes), CD8 (cytotoxic T lymphocytes), GB4 (activated cytotoxic T lymphocytes), L26 (pan B lymphocytes), CD56 and CD57 (NK/K cells). Lymphocyte subsets were investigated with regard to quantity and distribution within liver tissue. For control ten cases of PBC were also investigated simultaneously. NSBDD was found in five, granulomas in three cases. Portal inflammation was seen in all cases. In 9 cases T cells outweighed B cells. GB4 positive activated cytotoxic T lymphocytes were found within bile duct epithelium in five cases. All these cases showed associated NSBDD. NK/K cells were seen infrequently. Similar findings were observed in the ten cases of PBC. We therefore conclude that bile duct destruction in AIC is mediated by activated cytotoxic T lymphocytes. AIC cannot be differentiated from PBC histologically or by immunomorphology.

Antibodies, Antinuclear

Anti-gp210 antibodies in sera of patients with primary biliary cirrhosis. Identification of a 64 kD fragment of gp210 as a major epitope.

Patients with primary biliary cirrhosis (PBC) frequently produce autoantibodies against gp210, an integral glycoprotein of the nuclear pores. this protein consists of three main domains: a large glycosylated lumenal domain, a single hydrophobic transmembrane segment and a short cytoplasmic tail. It has been previously shown that autoantibodies from PBC patients exclusively react with the cytoplasmic tail when recombinant rat gp210 expressed in Escherichia coli was used as antigen. Using human gp210 isolated from HeLa cells we found the lumenal domain as the major target. The aim of this study was to further characterize the dominant autoepitopes of gp210. Sera from 88 patients with autoimmune liver disease and 20 controls were used. Gp210 protein was digested with papain or endoglycosidase H and then subjected to immunoblotting. Autoantibodies against gp210 were detected in 12 of 43 (28%) PBC patients, but in none of the autoimmune hepatitis and control sera. Four of 12 (33%) anti-gp210 positive sera reacted with a fragment consisting of the cytoplasmic tail and 8 (66%) sera targeted an epitope located within the large lumenal domain. Furthermore, our data show that antigenic determinant is restricted to the 64 kD glycosylated amino-terminal fragment and that carbohydrate residues are an essential part of this novel epitope. We suggest that antigens possessing both epitopes namely; the glycosylated lumenal domain and the cytoplasmic tail should be used for screening tests in order to detect all sera with anti-gp210 specificity.

Animals

Autoantibodies from patients with primary biliary cirrhosis preferentially react with the amino-terminal domain of nuclear pore complex glycoprotein gp210.

Patients with primary biliary cirrhosis frequently develop autoantibodies directed to gp210, a major glycoprotein of the nuclear pore complex. This protein contains a large glycosylated cisternal domain, a single transmembrane segment, and a short cytoplasmic tail. It has been previously shown that autoantibodies from primary biliary cirrhosis patients exclusively react with the cytoplasmic tail. We demonstrate that autoantibodies against gp210 recognize at least two different epitopes. 4 out of 12 anti-gp210 positive sera reacted with the fragment consisting of the cytoplasmic tail, and 8 sera targeted a novel epitope located within the large glycosylated lumenal domain. Moreover, our data prove that carbohydrate moieties are an essential part of this novel epitope. We propose, therefore, that future screening assays should be performed with antigens possessing both epitopes to detect all sera with anti-gp210 specificity.

Antibody Specificity

Manifestation late in life of idiopathic adulthood ductopenia.

Idiopathic adulthood ductopenia is a chronic cholestasic liver disease of unknown etiology characterized by the loss of interlobular bile ducts. We describe three patients who fulfilled the diagnostic criteria of idiopathic adulthood ductopenia, but differed from the cases reported so far in late manifestation of the disease and a benign clinical course despite histologic evidence of ongoing cholangitis. Treatment with ursodeoxycholic acid in one patient resulted in improvement of biochemical markers of cholestasis, suggesting that chronic cholestasis in idiopathic adulthood ductopenia can be influenced beneficially.

Aged

Screening for celiac disease in first-degree relatives of patients with celiac disease by lactulose/mannitol test.

OBJECTIVES: In first-degree relatives of celiac patients, the risk of oligosymptomatic celiac disease is elevated. These individuals therefore also have a higher potential for malignancy or nutritional deficiencies. Lactulose/mannitol permeability is increased in untreated celiac patients and has been recommended to screen for celiac disease. We investigated the usefulness of a lactulose/mannitol home test kit for screening first-degree relatives home test kit for screening first-degree relatives of celiac patients. METHODS: The lactulose/mannitol test was performed at home by 111 first-degree relatives. These subjects received the test kit from celiac index patients, were instructed by an information sheet how to carry out the test, and were asked about their symptoms by questionnaire. When lactulose/mannitol permeability was abnormal, endomysial antibodies were tested by immunofluorescence. Any relatives with positive endomysial antibodies were then biopsied. To investigate the specificity of the lactulose/mannitol test for celiac disease, 40 patients with nonspecific gastrointestinal symptoms were tested. RESULTS: Lactulose/mannitol permeability was elevated in 34 (31%) relatives, but only nine (8%) of those relatives showed positive endomysial antibodies. Flat mucosa was found in all nine relatives after biopsy. The prevalence of celiac disease was much higher (42%) among 12 relatives who contacted the outpatient clinic themselves because of symptoms. Seventy-one percent of the remaining 21 relatives with elevated permeability demonstrated normal intestinal permeability at a control test within 1 yr. CONCLUSION: By combining the lactulose/mannitol test with endomysial antibody testing, we have developed a good strategy for use in screening for celiac disease among first-degree relatives.

Adolescent

Screening for celiac disease: a prospective study on the value of noninvasive tests.

OBJECTIVE: Celiac disease is frequently diagnosed in patients with nonspecific abdominal symptoms. Therefore, highly sensitive, specific, and simple noninvasive screening tests are needed. METHODS: This study compared the usefulness of IgG- and IgA-antigliadin antibodies, IgA-endomysial antibodies, and intestinal permeability in diagnosing celiac disease in 102 adult patients with nonspecific abdominal symptoms. In addition, all patients underwent small bowel biopsy as a gold standard for the diagnosis of celiac disease. RESULTS: Forty-nine patients were ultimately diagnosed as having celiac disease because of flat mucosa. Flatulence and signs and symptoms dating back to childhood were more frequent and abdominal pain less frequent (p < 0.05) in celiac disease but were not helpful for screening. IgA-endomysial antibodies showed a sensitivity and specificity of 100%; an altered intestinal permeability had also a 100% sensitivity, but only 55% specificity. IgG- and IgA-antigliadin antibodies' sensitivity (73% and 82%, respectively) and specificity (74% and 83%, respectively) were much lower. Combining the two antigliadin antibodies did not significantly improve the sensitivity and specificity. CONCLUSIONS: Our data show the advantage of IgA-endomysial antibodies for screening of celiac disease except in the case of patients with IgA-deficiency or dermatitis herpetiformis. In these patients, the permeability test could improve noninvasive differential diagnosis.

Adult

Autoantibodies against constituents of nuclear pore complexes in patients with primary biliary cirrhosis and autoimmune hepatitis.

Sera obtained from patients with autoimmune liver disease were screened in indirect immunofluorescence microscopy for the presence of autoantibodies. Patients' sera, which strongly stained nuclei (ANA) with peripheral accentuation, were used for further experiments to define the corresponding antigen(s). Nuclei and nuclear subfractions were isolated from HeLaS3 cells and used as antigen source. Immunoblotting experiments were performed after separation of nuclear proteins by one- and two-dimensional polyacrylamide gel electrophoresis. Some ANA positive sera recognized the nuclear protein with molecular mass of approximately 200 kDa. Further analysis revealed that the patients' sera reacted with gp210, an integral protein of the nuclear pores. The incidence and clinical significance of these antibodies is discussed.

Autoantibodies

Antinuclear antibody profile in UCD line 200 chickens: a model for progressive systemic sclerosis.

The fully blown disease of human progressive systemic sclerosis (PSS, scleroderma) is serologically associated with the emergence of several types of autoantibodies, some of them regarded as more specific for scleroderma (e.g. Scl-70, anti-centromere) and some common also to other connective tissue diseases (e.g. anti-ssDNA). Since most patients suffering from PSS are not under medical control until clinical manifestations are fully established, only scarce data are available on the dynamics and clinical significance of autoantibodies in the very early stages of this systemic fibrotic disease. The University of California at Davis line 200 (UCD 200) of chickens spontaneously develop a PSS-like disorder with an acute inflammatory stage around 60 days after hatching, leading to fibrosis with fast progression. In order to address a possible correlation between the occurrence and titer of autoantibodies and the initial disease activity, we have chronologically investigated the presence and titer of autoantibodies directed against several human nuclear antigens in this animal strain. In UCD-200 chickens, we found a progressive increase in autoantibodies to histones, to ssDNA and--to a lesser degree--dsDNA with peaks at the age of 60 and 120 days, to poly(I) and poly(G) with a peak at 120 days and an elevation in anti-cardiolipin antibodies. Total immunoglobulin concentrations, anti-Ro, anti-La and anti-Sm showed no significant differences as compared to negative results in healthy normal controls. Our data reveal parallels in the antinuclear antibody (ANA) spectrum between UCD-200 chickens and human autoimmune collagen diseases, but do not reflect the typical ANA spectrum found in the foudroyant form of diffuse scleroderma.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors