Generation of cytotoxic donor CD8+ T cells against relapsing leukemic cells following allogeneic transplantation by stimulation with leukemic cell- or leukemic lysate pulsed donor cell-derived dendritic cells

To treat leukemia relapse after allogeneic hematopoietic stem cell transplantation (HSCT), we investigated the possibility of immunotherapy using donor CD8+ T cells that were generated by stimulating leukemic cell-derived dendritic cells (leukemic-DCs) or leukemic cell lysate pulsed donor cell-derived DCs (donor-DCs). Leukemic- and donor-DCs were generated from mononuclear cells of patients and CD14+ cells of HLA-matched donors, respectively. The expression of CD80, CD83, CD86, CD1a, and CD40 on leukemic-DCs was significantly lower than that on donor-DCs. Donor-DCs exhibited a higher capacity to stimulate allogeneic T cells compared with leukemic-DCs. Donor CD8+ T cells stimulated by leukemic- or donor-DCs were more cytotoxic than unprimed CD8+ T cells, and slightly higher cytotoxicity was observed with donor-DCs compared to leukemic-DCs. This study indicates that leukemic- or donor-DCs pulsed with leukemic cell lysates can effectively prime donor cytotoxic T cells in vitro, and that they may be used as a potential alternative tool for treating leukemic patients who relapse after allogeneic HSCT.

Insulin sensitivity in physically fit and unfit children of parents with Type 2 diabetes

AIMS

First-degree relatives of patients with Type 2 diabetes mellitus (T2DM) are often reported to be insulin resistant. We wanted to identify early metabolic abnormalities in this condition, and determine whether they are altered by regular physical training.

METHODS

We measured insulin sensitivity using the euglycaemic glucose clamp technique and insulin response to oral glucose in 10 unfit (did not participate in routine physical exercise) offspring of T2DM parents and 10 unfit control subjects, and compared them with six fit (routinely swam for 3 h/day 5 days/week) offspring of T2DM parents and six fit controls with no family history of T2DM.

RESULTS

Unfit offspring had a higher plasma glucose response than the other three groups. The mean area under the glucose curve was also significantly higher in unfit offspring than in the other three groups (12.6 +/- 0.6 vs. 10.4 +/- 0.4, 9.6 +/- 0.5, and 9.5 +/- 0.7 mmol/l per hour for the unfit controls, fit offspring and fit controls, respectively; P < 0.05). The corresponding insulin response of unfit offspring was significantly higher at 60 min in the oral glucose tolerance test (OGTT) that that of fit offspring or fit controls. In addition, the mean area under the insulin curve was significantly greater in unfit offspring than in either fit offspring or fit controls (868 +/- 172 vs. 294 +/- 71, 287 +/- 43 mmol/l per hour, respectively; P < 0.05). Moreover, the glucose disposal rate (GDR), measured using a euglycaemic clamp, was significantly lower in unfit and fit offspring than in unfit and fit controls (5.6 +/- 0.3 vs. 8.6 +/- 0.3 mg/kg per minute; P < 0.01 and 9.3 +/- 0.9 vs. 12.1 +/- 0.8 mg/kg per minute, respectively; P < 0.015), whereas the GDR was similar in unfit controls and fit offspring (8.6 +/- 0.4 vs. 9.3 +/- 0.9 mg/kg per minute; P > 0.05).

CONCLUSION

These results support the concept that early metabolic abnormalities, as reflected by a decreased GDR (insulin sensitivity) in the offspring of T2DM patients, may be improved by increased physical fitness.

Clinicopathologic analysis of fine needle aspiration cytology of the thyroid. A review of 1,613 cases and correlation with histopathologic diagnoses

OBJECTIVE

To evaluate the accuracy of fine needle aspiration (FNA) of thyroid lesions at our institution and to ascertain its usefulness in determining the therapeutic approach.

STUDY DESIGN

The authors reviewed the results of 1,613 cases of FNA cytology of thyroid nodules performed from 1999 to 2001 at the Department of Pathology, Chonnam National University Hospital. Cytologic diagnoses were compared with histologic diagnoses in 207 cases that included both FNA and thyroid surgery.

RESULTS

The sensitivity for the detection of neoplasms (carcinoma and follicular adenoma) was 78.4% and the specificity 98.2%. A false positive diagnosis was made in 1 case (1.8%) and false negative ones in 28 cases (21.5%). The diagnostic accuracy was 84.4%, with a positive predictive value of 99.0% and negative predictive value of 66.3%. The predictive value of a cytologic diagnosis was 100% in papillary carcinoma.

CONCLUSION

FNA is a useful test in determining the therapeutic approach of thyroid lesions.

Application of cDNA microarray technique to detection of gene expression in host cells infected with viruses

cDNA microarray technique was used to monitor changes in mRNA levels in cells after Hantaan virus (HTNV) infection. The values of the ratio of medians for HTNV and Japanese encephalitis virus (JEV) at the early stage of infection were compared and found similar, suggesting that the same or similar genes are associated with the early events of infection with either virus. The reproducibility of values of the "ratio of medians" for HTNV was examined. We found that applying cluster analysis to the gene expression data groups efficiently together genes with the same function. Therefore, in analyzing the effects of viral infection on host cells by the cDNA microarray technique, clustering data appear to be necessary for gaining biological meaning from a dump of gene expression profiles obtained from virus-infected cells.

Inverse relationship between APC gene mutation in gastric adenomas and development of adenocarcinoma

Gastric cancer is common among the world, but genetic mechanisms of gastric carcinogenesis are not well understood. Gastric polypoid adenomas and flat dysplasias are regarded as precursor lesions. However, a detailed molecular study of these lesions has not been done to determine their role as precancerous lesions. We investigated mutations of the APC, beta-catenin, and K-ras genes, and microsatellite instability (MSI) status in 35 adenomas and 47 flat dysplasias without adenocarcinoma, 35 adenomas/dysplasias associated with adenocarcinomas, and 39 adenocarcinomas (20 diffuse type and 19 intestinal type). Somatic APC gene mutations were identified in 76% (59 of 78) of adenomas or flat dysplasias without associated adenocarcinoma, but in only 3% (1 of 30) of adenomas/dysplasias associated with adenocarcinoma, and in only 4% (3 of 69) of adenocarcinomas (P < 0.000001). No mutations of beta-catenin were found in adenocarcinomas, or adenomas/dysplasia without APC mutation. K-ras mutations were detected in 5% (4 of 82) of gastric adenomas/dysplasia without carcinoma, 3% (1 of 39) of adenocarcinomas without associated adenoma/dysplasia, and not in 32 adenocarcinomas with associated adenoma/dysplasia. High level of MSI (MSI-H) was more frequent in gastric adenoma/dysplasia associated with carcinoma (17%, 6 of 35) than in adenomas/dysplasia without carcinoma (3%, 2 of 75; P = 0.01). MSI-H was also more frequent in intestinal type adenocarcinoma (20%, 11 of 54) than in diffuse type (0%, 0 of 20; P = 0.03). APC gene mutations were present in six of nine (67%) of gastric adenomas/dysplasias with low level of MSI, but in none of the eight adenomas/dysplasia with MSI-H phenotype (P = 0.009). Our results indicate that somatic mutation of the APC gene plays an important role in the pathogenesis of gastric adenoma and dysplasia but has a limited role in neoplastic progression to adenocarcinoma. Gastric adenomas or dysplasias without APC mutations but with or without MSI may have a different biological behavior, and are precursors of intestinal-type of gastric adenocarcinomas.

Clinical characteristics, GAD antibody (GADA) and change of C-peptide in Korean young age of onset diabetic patients

AIMS

To investigate the association of clinical and immunological markers with diabetes classification in newly diagnosed young diabetic patients at disease onset.

METHODS

Eighty-two diabetic patients recruited within 1 year of onset (mean age 23.0 +/- 7.1, M:F = 46:36) were divided into three groups, namely: a low fasting C-peptide (FC) level at baseline group (the low FC group (n = 14, FC < 0.18 nmol/l)), an intermediate FC group (n = 29, 0.18 nmol/l < or = FC < 0.37 nmol/l), and a high FC group (n = 39, 0.37 nmol/l < or = FC). Patients were reclassified at follow-up (mean follow-up period 3.7 +/- 1.4 years) in the same manner as described above into low FC group (n = 31), intermediate FC group (n = 20), and high FC group (n = 31). The clinical characteristics and prevalence of GADA were compared.

RESULTS

Patients in the high FC group at baseline had a higher body mass index (BMI), a higher frequency of a family history of diabetes, a higher meal-stimulated C-peptide increment, a lower frequency of ketonuria, a lower frequency of history of diabetic ketoacidosis, and a lower frequency of insulin therapy at diagnosis than those in the low and intermediate FC groups at baseline. Insulin secretory capacity, which was represented by fasting C-peptide, was affected by BMI at diagnosis and the presence of GADA. All the patients of the low FC group on follow-up were finally classified as having Type 1 diabetes; moreover, the factors that determined the type of diabetes were lower BMI at onset, GADA positivity, insulin therapy, lower fasting C-peptide level and lower meal-stimulated C-peptide increment at initial admission.

CONCLUSIONS

Our study suggests that follow-up involving C-peptide and GADA measurements in combination with clinical characteristics is useful for discriminating between the types of diabetes in these groups.

Relationships of urinary phyto-oestrogen excretion to BMD in postmenopausal women

OBJECTIVE

Phyto-oestrogens are plant compounds with both oestrogenic and anti-oestrogenic properties. However, it is not known whether natural phyto-oestrogens are beneficial or harmful in human osteoporosis. This study was performed to investigate the relationships between urinary phyto-oestrogens and bone mineral density (BMD) in Korean postmenopausal women.

DESIGN

The subjects were classified into osteoporotic, osteopenic and normal groups according to their BMD as defined by WHO criteria. We compared the urinary phyto-oestrogens of each group and studied whether urinary phyto-oestrogens correlate with BMD.

PATIENTS

The subjects were 75 Korean postmenopausal women with ages ranging from 52 to 65 years (mean 58 +/- 1.1 years). Mean number of years after menopause was 7.3 +/- 1.3.

MEASUREMENTS

Twenty-four-hour urinary phyto-oestrogens were measured by gas chromatography-mass spectrometry (GCMS) and BMD by dual-energy X-ray absorptiometry (DXA, Lunar Expert-XL, Lunar Co., WI, USA).

RESULTS

In Korean postmenopausal women, urinary enterolactone (1.46 +/- 1.11 micromol/day) was lower and daidzein (2.59 +/- 3.25 micromol/day) was higher than in western women, and both levels were comparable to those in Japanese women. Daily urinary excretion of genistein and apigenin were 1.09 +/- 0.912 and 0.48 +/- 0.40 micromol/day, respectively. In subjects with osteoporosis, urinary enterolactone was lower (P < 0.05) but apigenin was significantly higher (P < 0.05) than in the controls. BMD of L2-L4 correlated positively with urinary enterolactone (r = 0.388, P < 0.01), and BMD of the femoral neck and Ward's triangle correlated positively with urinary enterolactone (r = 0.271, P < 0.05 and r = 0.322, P < 0.05) but negatively with apigenin (r = -0.412, P < 0.01 and r = -0.395, P < 0.01). By multiple stepwise regression, the variables associated with spinal BMD were age, the amount of urinary apigenin and body mass index (BMI). The variables associated with femoral neck BMD were age and urinary apigenin.

CONCLUSIONS

From these results, we conclude that urinary phyto-oestrogens, especially enterolactone and apigenin, are related to BMD in Korean postmenopausal women. Our results also suggest the possibility that phyto-oestrogens have differential effects on bone density. Further studies are needed to clarify the exact biological roles of phyto-oestrogenic components on bone metabolism.

Prenatal detection of mesoblastic nephroma by sonography and magnetic resonance imaging

Congenital mesoblastic nephroma is the most common neonatal kidney tumor and surgical excision is almost always curative. We report the prenatal detection of congenital mesoblastic nephroma by sonography and magnetic resonance imaging. After birth, a right nephrectomy was performed and the baby recovered well.

Conjugation of low-molecular-weight heparin and deoxycholic acid for the development of a new oral anticoagulant agent

BACKGROUND

Heparin administration is usually limited to intravenous or subcutaneous injection. Oral delivery of heparin is an alternative to this and has been in great demand for treating patients who are at a high risk of deep vein thrombosis or pulmonary embolism. In this study, new heparin derivatives were synthesized to enhance the oral absorption of heparin in the gastrointestinal tract. Methods and Results- By using heparin of 3000 Da [LMWH(3 kDa)], heparin of 6000 Da [LMWH(6 kDa)], and unfractionated heparin (UFH), we synthesized 3 kinds of conjugates of heparin and deoxycholic acid (DOCA): LMWH(3 kDa)-DOCA, LMWH(6 kDa)-DOCA, and UFH-DOCA. After oral administration of 100 mg/kg of heparin-DOCA, the maximum activated partial thromboplastin times of the LMWH(3 kDa)-DOCA, LMWH(6 kDa)-DOCA, and UFH-DOCA were 31.0+/-6.0, 87.8+/-11.1, and 51.0+/-8.7 seconds, respectively. The peak plasma concentrations of LMWH(3 kDa)-DOCA, LMWH(6 kDa)-DOCA, and UFH-DOCA were 0.06+/-0.02, 0.76+/-0.15, and 0.41+/-0.13 IU/mL, respectively. The bioavailability of LMWH(6 kDa)-DOCA at the 20-mg/kg dosage was calculated to be 7.8%.

CONCLUSIONS

LMWH(6 kDa)-DOCA was found to have a high anticoagulant effect when administered orally and could be used as a new oral anticoagulant agent. Furthermore, the present work proposed a new method for oral delivery of macromolecules and polysaccharide drugs.

Diabetes mellitus induces vaginal tissue fibrosis by TGF-beta 1 expression in the rat model

The commonly reported sexual problem in women with diabetes mellitus is lack of vaginal lubrication. It is our hypothesis that reduced vaginal lubrication in diabetic women may result from the structural changes of the vagina. The aim of this study was to investigate in the diabetic rat model the vaginal structures using histochemistry and the expression of TGF-beta 1 using immunohistochemistry. Twenty female Sprague-Dawley rats (200-210 g) were divided into two groups: control and experimental. The experimental group (n = 10) received intravenous injection of streptozotocin (50 mg/kg). After 4 weeks, blood glucose levels were measured, and the vagina of the rat was excised. Serial sections of the vagina were used to perform hematoxylin and eosin (H & E) and Masson's trichrome stains, and for immunohistochemistry to identify TGF-beta 1 expression. The mean blood glucose concentrations were 67 +/- 11 mg/dL (range; 50-85) in the control group and 522 +/- 61 mg/dl (range; 429-590) in the experimental group. In the diabetic animals, vaginal tissue revealed reduced epithelial layers and decreased vaginal submucosal vasculatures compared to the control animals. The collagen connective tissue in the submucosal area of the diabetic animal tissue showed a dense and irregular, distorted arrangement. The immunoreactivity of TGF-beta 1 in the diabetic animals was prominent in the collagen connective tissue, fibroblasts, and smooth muscle fibers, whereas no immunoactivity was detected in the vaginal structures of the control animals. Diabetes mellitus may induce vaginal tissue fibrosis by TGF-beta 1 expression in the rat model. This implies that reduced vaginal lubrication in the diabetic women may result from the structural changes of the vagina.

Short report: genetic heterogeneity of Japanese encephalitis virus assessed via analysis of the full-length genome sequence of a Korean isolate

We determined the full-length genome sequence of Japanese encephalitis virus (JEV) K94P05 isolated in Korea. Sequence analysis showed that the 10,963-nucleotide-long RNA genome of K94P05 was 13 or 14 nucleotides shorter than the genome of other JEV isolates because of a deletion in the 3' noncoding region of K94P05. Compared with sequences of other JEV isolates, the full-length nucleotide sequence showed 89.0-89.6% homology, and the deduced amino acid sequence showed between 96.4-97.3% homology. A region of approximately 60 nucleotides immediately downstream of the open reading frame stop codon of K94P05 showed high sequence variability as compared with other JEV isolates. K94P05 formed a distinct group within a phylogenetic tree established with the full-length genome sequences. Cross-neutralization studies showed that polyclonal antibodies to Korean isolates were 3 times better at neutralizing the Korean isolates than antibodies to Nakayama-NIH. These findings suggest that Korean JEV K94P05 is genetically and antigenically distinct from other Asian JEV isolates.

Maternal-fetal n-6 and n-3 polyunsaturated fatty acids gradient in plasma and red cell phospholipids

Fatty acid distribution was investigated in ethnically and economically homogenous Korean mothers (n = 40) and neonates. Venous blood, maternal before delivery and cord, was obtained. Choline (CPG) and ethanolamine (EPG) phosphoglycerides and sphingomyelin (SM) were assayed. Mean arachidonic acid (AA) level was higher in plasma CPG and SM (p < 0.0001), and red cell CPG (p < 0.0001), EPG (p < 0.0001) and SM (p = 0.005) of the neonates. Similarly, the neonates had higher proportions of docosahexaenoic acid (DHA) in plasma CPG (p < 0.0001) and red cell CPG (p = 0.001) and EPG (p = 0.036). In contrast, linoleic and alpha-linolenic acids were significantly higher in maternal blood. Mead acid was elevated in plasma CPG (p < 0.0001) and red cell CPG and EPG (p < 0.0001) of the neonates. Consistent with data from high-fat-intake populations, our subjects, whose traditional diet is low in fat, exhibited maternal-fetal gradient in AA and DHA in plasma and red cell phospholipids. This may be due to an imbalance between supply and maternal and fetal requirements, and/or a physiological response to pregnancy. Prenatal nutritional constraint is associated with impaired development and a risk of chronic diseases in adults. AA and DHA are vital nutrients. Hence, there is a need to investigate whether the discrepancy between maternal and neonatal AA and DHA is a manifestation of nutritional insufficiency.

High-level expression of hepatitis C virus (HCV) structural proteins by a chimeric HCV/BVDV genome propagated as a BVDV pseudotype

A chimeric cDNA genome was constructed in which the core, E1 and E2 genes of hepatitis C virus (HCV) replaced the core, E(rns), E1 and E2 genes of bovine viral diarrhea virus (BVDV). High levels of HCV structural proteins were expressed in a small number of human or bovine cells following transfection with chimeric RNA. However, in one cell line, bovine embryonic trachea cells [EBTr(A)], the number of cells expressing HCV proteins increased to greater than 70% following serial passage of culture medium. These cells were persistently infected with a non-cytopathogenic BVDV helper virus. In these cells, the chimeric genome was packaged into infectious particles that accumulated in the culture medium at a titer as high as 10(7)-10(9) genome equivalents per ml. The virus particles were pseudotypes, because they were neutralized by anti-BVDV but not by anti-HCV.

Reduction of simian-human immunodeficiency virus 89.6P viremia in rhesus monkeys by recombinant modified vaccinia virus Ankara vaccination

Since cytotoxic T lymphocytes (CTLs) are critical for controlling human immunodeficiency virus type 1 (HIV-1) replication in infected individuals, candidate HIV-1 vaccines should elicit virus-specific CTL responses. In this report, we study the immune responses elicited in rhesus monkeys by a recombinant poxvirus vaccine and the degree of protection afforded against a pathogenic simian-human immunodeficiency virus SHIV-89.6P challenge. Immunization with recombinant modified vaccinia virus Ankara (MVA) vectors expressing SIVmac239 gag-pol and HIV-1 89.6 env elicited potent Gag-specific CTL responses but no detectable SHIV-specific neutralizing antibody (NAb) responses. Following intravenous SHIV-89.6P challenge, sham-vaccinated monkeys developed low-frequency CTL responses, low-titer NAb responses, rapid loss of CD4+ T lymphocytes, high-setpoint viral RNA levels, and significant clinical disease progression and death in half of the animals by day 168 postchallenge. In contrast, the recombinant MVA-vaccinated monkeys demonstrated high-frequency secondary CTL responses, high-titer secondary SHIV-89.6-specific NAb responses, rapid emergence of SHIV-89.6P-specific NAb responses, partial preservation of CD4+ T lymphocytes, reduced setpoint viral RNA levels, and no evidence of clinical disease or mortality by day 168 postchallenge. There was a statistically significant correlation between levels of vaccine-elicited CTL responses prior to challenge and the control of viremia following challenge. These results demonstrate that immune responses elicited by live recombinant vectors, although unable to provide sterilizing immunity, can control viremia and prevent disease progression following a highly pathogenic AIDS virus challenge.

beta-Cell dysfunction rather than insulin resistance is the main contributing factor for the development of postrenal transplantation diabetes mellitus

BACKGROUND

Our study was undertaken to investigate the pathogenesis and possible risk factors for postrenal transplantation diabetes mellitus (PTDM).

METHODS

We recruited 114 patients with normal glucose tolerance (NGT) and performed both 75-g oral glucose tolerance tests (OGTT) and short insulin tolerance tests 1 week before and 9-12 months after transplantation.

RESULTS

The subjects were classified into three groups by World Health Organization criteria on the basis of OGTT after transplantation: (a) 36 (31.6%) subjects with normal glucose tolerance; (b) 51 (45.7%) subjects with impaired glucose tolerance (IGT); and (c) 27 (23.7%) subjects with postrenal transplantation diabetes mellitus. Dosages of steroid and cyclosporine were equivalent among the three groups. Before transplantation, the fasting and 2-hr plasma glucose and proinsulin/insulin (PI/I) ratios were significantly higher in the IGT and PTDM groups than in the NGT group, but the insulin sensitivity index (ISI) was not significantly different among the three groups. In addition, the area under the curve-insulin on OGTT was significantly lower in the PTDM group than in the NGT group. After transplantation, however, the ISI was increased in all groups. Furthermore, the ISI and PI/I ratios revealed significantly higher values in the PTDM group than in the NGT group after transplantation.

CONCLUSIONS

These results revealed that fasting and 2-hr plasma glucose levels, as well as the proinsulin/insulin ratio before transplantation, are both possible indicators of beta-cell dysfunction and may be predictors for the development of PTDM. Furthermore, beta-cell dysfunction, rather than insulin resistance, was proven to be the main factor for the pathogenesis of PTDM.

Elicitation of high-frequency cytotoxic T-lymphocyte responses against both dominant and subdominant simian-human immunodeficiency virus epitopes by DNA vaccination of rhesus monkeys

Increasing evidence suggests that the generation of cytotoxic T-lymphocyte (CTL) responses specific for a diversity of viral epitopes will be needed for an effective human immunodeficiency virus type 1 (HIV-1) vaccine. Here, we determine the frequencies of CTL responses specific for the simian immunodeficiency virus Gag p11C and HIV-1 Env p41A epitopes in simian-human immunodeficiency virus (SHIV)-infected and vaccinated rhesus monkeys. The p11C-specific CTL response was high frequency and dominant and the p41A-specific CTL response was low frequency and subdominant in both SHIV-infected monkeys and in monkeys vaccinated with recombinant modified vaccinia virus Ankara vectors expressing these viral antigens. Interestingly, we found that plasmid DNA vaccination led to high-frequency CTL responses specific for both of these epitopes. These data demonstrate that plasmid DNA may be useful in eliciting a broad CTL response against multiple epitopes.

Lymphonodular cryptococcosis diagnosed by fine needle aspiration cytology in hyper-IgM syndrome. A case report

BACKGROUND

Most cases of cryptococcosis are diagnosed when signs of meningitis have appeared. We report a case of lymphonodular cryptococcosis that was diagnosed by fine needle aspiration cytology (FNAC), excisional biopsy of a cervical lymph node and culture of aspirated material.

CASE

An 11-year-old boy presented with a history of fever and enlarged bilateral cervical lymph nodes of two weeks' duration. Past medical history included immunoglobulin replacement for hyper-IgM syndrome for the previous eight years. FNAC smears from a cervical lymph node showed numerous yeasts of various sizes, ranging from 5 to 15 microns in diameter, located in the cytoplasm of multinucleated giant cells and in the background. In air-dried, Diff-Quik-stained slides, the yeasts stained blue and were surrounded by clear halos. Aspirated material collected in the syringe was cultured, and Cryptococcus neoformans was isolated.

CONCLUSION

This case report suggests that a combination of FNAC and culture is a simple and useful method of diagnosing fungal infections. Early diagnosis by FNAC makes possible the early initiation of treatment.

The progression of mediastinal lymphangioma in utero

We describe a case of mediastinal lymphangioma that suddenly progressed in utero. The initial sonographic impression was one of pericardial effusion while the follow-up examination revealed a mediastinal cystic mass. At 35 weeks of gestation preterm labor occurred. An ultrasound examination performed at this time demonstrated the mediastinal cyst with internal hemorrhage and fetal hydrops. The cystic mass was resected 5 days after birth. The diagnosis of lymphangioma was made from histological examination. The infant was followed up for 18 months and remained well. We recommend frequent prenatal sonographic follow-up when a localized fluid collection is, shown in the mediastinum.

Identification of glucokinase mutation in subjects with post-renal transplantation diabetes mellitus

Mutations in the glucokinase (GCK) gene are considered to be a possible cause of maturity-onset diabetes of the young. The purpose of this study was to evaluate the contribution of this gene to the development of post-renal transplantation diabetes mellitus (PTDM). Identification of the GCK mutation was attempted in 58 selected renal allograft recipients with PTDM and 45 normal controls. The exons in the GCK gene were examined using polymerase chain reaction (PCR), followed by an analysis of single-stranded DNA conformational polymorphism (SSCP). The abnormal bands were then confirmed by DNA sequencing analysis. The family members of the patients affected with GCK mutation were also examined. Two of the 58 PTDM patients (3. 4%) were found to have GCK mutations. One had the mutation on exon 5 and the other on intron 7. One control subject had the mutation on intron 9. The mutation on exon 5 was identified as a substitution of CCT (proline) for CTT (leucine) at codon 164, which has never been reported before. The family members of the PTDM patient with a mutation on exon 5 were analyzed by PCR, followed by SSCP, and two of them had the same mutation. The abnormal band seen on SSCP analysis of exon 7 was identified as the C-->T substitution at the 39th nucleotide in intron 7. Two of the family members also displayed the same bands on the SSCP. One of the 45 normal controls had a known polymorphism located at the 8th nucleotide in intron 9. We found a GCK mutation on the exon in subjects with PTDM and we speculate that this mutation may be one of the possible contributing factors of PTDM, although variations of the GCK gene are not common causes of PTDM.

Variance of high contrast textures is sensed using negative half-wave rectification

A rectifying transformation is required to sense variations in texture contrast. Various theoretical and practical considerations have inclined researchers to suppose that this rectification is full-wave, rather than half-wave. In the studies reported here, observers are asked to judge which of two texture patches has higher texture variance. Textures are composed of small squares, with each square being painted with one of nine different luminances. Different texture variances are achieved by manipulating the histograms of the texture patches to be compared. When the nine luminances range linearly from 0 to 160 cd/m(2), the transformation mediating judgments of texture variance takes the form of a negative half-wave rectifier: texture variance judgments are determined exclusively by the frequencies of luminances below mean luminance in the textures being compared. However, when the nine luminances range linearly from 60 to 100 cd/m(2), two of three observers use a full-wave rectifying transformation in making texture variance judgments; the third observer continued to use a negative half-wave rectifier. The unexpectedly asymmetric roles played by low versus high luminances in texture variance judgments suggest that the off-center system may play a dominant role in human perception of texture contrast.

Texture luminance judgments are approximately veridical

This paper investigates intensity coding in human vision. Specifically, we address the following question: how do different luminances influence the perceived total luminance of a composite image? We investigate this question using a paradigm in which the observer attempts to judge, with feedback, which of two texture patches has higher total luminance. All patches are composed of nine luminances, ranging linearly from 0 (black) to a maximum luminance (white: 160 cd/m(2) in one condition; 20.2 cd/m(2) in another condition). Luminance histograms of the patches being compared are experimentally varied to derive, for each luminance nu, the impact exerted by texture elements (texels) of luminance nu on texture luminance judgments. We find that impact is approximately proportional to texel luminance; That is, a texture element exerts, on average, an impact on texture brightness (i.e. perceived texture luminance) that is proportional to its (the texel's) luminance. The only exception occurs for texels of maximal luminance, which surprisingly exert an impact that is slightly, but significantly, less than that exerted by texels of the next lower luminance. We conclude that visual intensity coding for purposes of assessing overall luminance of inhomogeneous patches is approximately veridical. In particular, texture luminance judgments are not mediated by a significant, compressive nonlinearity.

Apoplexy of pituitary macroadenoma after combined test of anterior pituitary function

Pituitary apoplexy has been reported as a very rare complication of combined tests of anterior pituitary function and of TRH or gonadotropin-releasing hormone (GnRH) administration in pituitary tumor. A 34-year-old man with a GH-secreting pituitary macroadenoma and diabetes mellitus received an injection of 400 microg TRH, 100 microg GnRH, and 0.15 U/Kg regular insulin. Twenty minutes later, he complained of a severe headache and vomited. Visual acuity and visual field did not change and his headache was persistent during the next 24 hours of conservative management. Magnetic resonance imaging (MRI) of the sella turcica done the day after the event showed definitive elevation of the optic chiasm and slight enlargement of tumor and focal areas of mixed high signal and low signal intensities in the macroadenoma on noncontrast T1-weighted images. Headache subsided markedly within a day of octreotide therapy. Transsphenoidal removal of the pituitary tumor was performed 9 days after the hormone study. Ischemic necrosis and hemorrhage were confirmed in the acidophilic adenoma with positive immunostaining for GH. Postoperative course was uneventful and his serum insulin-like growth factor-1 (IGF-1) level and blood glucose levels were normalized. Three months after the surgery the dynamic test was repeated without adverse effects. To our knowledge, this is a very rare case of apoplexy of GH-secreting pituitary adenoma after a combined stimulation test of anterior pituitary function.

Blood fatty acid composition of pregnant and nonpregnant Korean women: red cells may act as a reservoir of arachidonic acid and docosahexaenoic acid for utilization by the developing fetus

Relative fatty acid composition of plasma and red blood cell (RBC) choline phosphoglycerides (CPG), and RBC ethanolamine phosphoglycerides (EPG) of pregnant (n = 40) and nonpregnant, nonlactating (n = 40), healthy Korean women was compared. The two groups were of the same ethnic origin and comparable in age and parity. Levels of arachidonic (AA) and docosahexaenoic (DHA) acids were lower (P < 0.05) and palmitic and oleic acids higher (P < 0.0001) in plasma CPG of the pregnant women. Similarly, the RBC CPG and EPG of the pregnant women had lower AA and DHA (P < 0.05) and higher palmitic and oleic acids (P < 0.01). The reduction in DHA and total n-3 fatty acids in plasma CPG of the pregnant women was paralleled by an increase in docosatetraenoic (DTA) and docosapentaenoic (DPA) acids of the n-6 series and in DPA/DTA ratio. In the RBC phospholipids (CPG and EPG) of the pregnant women, DTA and DPA acids of the n-6 series and DPA/DTA ratio did not increase with the decrease of the n-3 metabolites (eicosapentaenoic acid, DPA, and DHA) and total n-3. Since pregnancy was the main identifiable variable between the two groups, the lower levels of AA and DHA in RBC CPG and EPG of the pregnant women suggest that the mothers were mobilizing membrane AA and DHA to meet the high fetal requirement for these nutrients. It may also suggest that RBC play a role as a potential store of AA and DHA and as a vehicle for the transport of these fatty acids from maternal circulation to the placenta to be utilized by the developing fetus.