Autosomal dominant cone-rod dystrophy with negative electroretinogram

AIMS

The negative electroretinogram (ERG) is observed in many hereditary retinal disorders. However, no reports have described a negative ERG in a family with autosomal dominant cone-rod dystrophy. A Japanese family with autosomal dominant cone-rod dystrophy with negative ERG is described.

METHOD

Members of a Japanese family with autosomal dominant cone-rod dystrophy were examined and evaluated with Goldmann and Humphrey perimetry, bright flash ERG with an intense white stimulus, rod, cone, and flicker ERGs, and fluorescein angiography. Molecular analysis of the rhodopsin and peripherin/RDS genes in the patients was also performed.

RESULTS

A 45-year-old Japanese man (proband) presented with decreased visual acuity. His fundi revealed bull's eye maculopathy and his single flash bright ERG showed a negative configuration. Negative ERG responses also were found in his father, who had macular degeneration, and one of the proband's three children who showed no fundus changes. No irregularities were found in their rhodopsin or peripherin/RDS genes.

CONCLUSION

The condition of this family is believed to represent a previously undescribed autosomal dominant cone-rod dystrophy.

Cloning and structural analysis of the mouse apolipoprotein B mRNA editing protein gene

Mouse apolipoprotein B mRNA editing protein gene has been isolated and characterized. The amino acid sequences deduced from the exonic sequences of the gene showed 90, 70 and 68% identity to those of rat, human and rabbit, respectively. RNA blotting experiments demonstrated high expression in small intestine especially in the jejunum as a major 2.4 kb mRNA species. mRNA in other tissues including the liver is smaller in amounts and larger in size (3.1 kb) than the intestinal mRNA. The gene spans 12 kb and contains 5 exons and 4 introns. Sequencing of the 5'-flanking region revealed that a canonical TATA box is absent and the consensus recognition sequences for several transcription factors have been identified.

Mucopolysaccharidosis IVA: identification of a common missense mutation I113F in the N-Acetylgalactosamine-6-sulfate sulfatase gene

Mucopolysaccharidosis IVA is an autosomal recessive lysosomal storage disorder caused by a deficiency of N-acetylgalactosamine-6-sulfate sulfatase. The recent isolation and characterization of cDNA and genomic sequences encoding GALNS has facilitated identification of the molecular lesions that cause MPS IVA. We identified a common missense mutation among Caucasian MPS IVA patients. The mutation was originally detected by SSCP, and successive sequencing revealed an A-->T transversion at nt 393. This substitution altered the isoleucine at position 113 to phenylalanine (I113F) in the 622 amino acid GALNS protein and was associated with a severe phenotype in a homozygote. Compound heterozygotes with one I113F-allele mutation have a wide range of clinical phenotypes. Transfection experiments in GALNS-deficient fibroblasts revealed that the mutation drastically reduces the enzyme activity of GALNS. Allele-specific oligonucleotide or SSCP analysis indicated that this mutation accounted for 22.5% (9/40) of unrelated MPS IVA chromosomes from 23 Caucasian patients, including 6 consanguineous cases. Of interest, the I1e 113-->Phe substitution occurred in only Caucasian MPS IVA patients and in none of the GALNS alleles of 20 Japanese patients. These findings identify a frequent missense mutation among MPS IVA patients of Caucasian ancestry, that results in severe MPS IVA when homoallelic, and will facilitate molecular diagnosis of most such patients and identification of heterozygous carriers. In addition to this common mutation, 10 different point mutations and 2 small deletions were detected, suggesting allelic heterogeneity in GALNS gene.

Evaluation of an allogeneic cultured dermal substitute composed of fibroblasts within a spongy collagen matrix as a wound dressing

The purpose of this study was to examine whether epithelialisation is promoted when an allogeneic cultured dermal substitute is used as a biological wound dressing. The dermal substitute was prepared by plating fibroblasts on to a spongy collagen matrix, and then culturing them for 7 to 10 days. A new animal wound model was designed to measure re-epithelialisation quantitatively. A full thickness skin defect was made on the dorsum of each of 33 rats; the skin was excised, leaving a layer of pannicular carnosus with an island of intact skin in the central portion of the skin defect. In the first group of rats (n = 13), a piece of cultured dermal substitute was applied to the wound, and a medicated covering material was placed over it. Re-epithelialisation from the island of intact skin was monitored over a period of 7 days. In the second group of rats (n = 10), the wound was covered with an acellular collagen matrix in conjunction with the medicated covering material, and in the third group of rats (n = 10), the wound was covered with the medicated covering material alone. Both the macroscopic and histological findings indicated that the epithelial migration of the first group of rats was far more rapid than that in the other two groups. It comes to the conclusion that the application of this new fibroblastic cultured dermal substitute provided a good environment for the promotion of wound healing.

Enhanced expression of transforming growth factor-beta and its type-I and type-II receptors in human glioblastoma

Immunohistochemical studies of transforming growth factor-beta (TGF-beta) and its receptors have been carried out on 16 glioma tissues and compared with 5 cases of gliosis. Significantly higher expressions of TGF-beta I, as well as type-I and type-II TGF-beta receptors (T beta R-I and T beta R-II, respectively), were observed in advanced-malignant-glioma tissues when compared with non-tumorous gliosis. Immunoreactivities of TGF-beta and T beta R-I were localized in the cytoplasm of spindle-shaped tumor cells surrounding proliferating vessels or around areas of necrosis. The advancing edge of the tumor clusters frequently stained positive. Similar expression patterns were found for TGF-beta 2 and TGF-beta 3, whereas only weak or no expression was found for endoglin. In low-grade astrocytomas and in gliosis cases, the expression was moderate for T beta R-I and weak for TGF-beta and T beta R-II. In 3 examined human malignant glioma cell lines, clear immunostainings were detected for TGF-beta and its receptors. Ligand-induced heteromeric complexes of the receptors were formed in these cell lines, but the amount of the receptors was less than that of mink lung epithelial cells, which are sensitive target cells for TGF-beta. TGF-beta I showed no growth-inhibitory activity on any of these glioma cell lines. These results suggest that malignant gliomas produce TGF-beta and receptors, but are refractory to TGF-beta, implying dysregulation in the signalling pathway in the tumor cells. It is possible that the released TGF-beta acts on neighboring cells and affects stromal growth, angiogenesis, metastasis or immune surveillance in human glioma.

Ultrahigh-resolution low-voltage SEM reveals ultrastructure of the glucan network formation from fission yeast protoplast

The refined field emission SEM, S-900 LV which gives better resolution especially at low voltages below 5 kV was developed for ultrahigh resolution scanning electron microscopy. A visualization test at x 300,000 was made using a gold-evaporated magnetic tape, and the resolution was found to be about 1 nm at 2.5 kV. The ultrastructure of the cell wall, especially the reverting glucan network, from the protoplast of Schizosaccharomyces pombe was studied using this improved ultrahigh-resolution low-voltage SEM (UHR-LVSEM). The results with uncoated reverting protoplasts observed with this microscope revealed that the network was originally formed as secreted particles scattered on the protoplast surface and these were subsequently stretched to microfibrils about 2 nm thick. The microfibrils were twisted around each other and joined together so that they developed into 8-nm-thick fibrils, forming a ribbon-shaped network of glucans about 16-nm-thick which covered the entire protoplast surface. The UHR-LVSEM images of reverting protoplasts treated with glucanase confirmed that the particles scattered on the protoplast surface in the initial stage of regeneration were glucan in nature.

[A case of papillary muscle rupture associated with acute inferior myocardial infarction]

A sixty-year-old man was admitted to our hospital due to prolonged left anterior chest oppression and hypotention. The electrocardiogram revealed acute inferior myocardial infarction, confirmed by the coronary angiography which showed occluded right coronary artery (RCA) at the segment 4AV. The intra-coronary pro-urokinase infusion and coronary angioplasty successfully revascularized the occluded 4AV segment. Although the 4AV segment perfused small area, he developed severe pulmonary edema on the second hospital day. A transesophageal echocardiography revealed severe mitral regurgitation due to posterior mitral valve prolapse by the ruptured tendineae with a mobile mass. The damaged mitral valve was replaced by the prosthetic mechanical valve (SJM 25M), resulted in stable hemodynamic state. He discharged one month after the operation.

[An analysis on fat digestion in the upper small intestine after intragastric infusion of a test meal in patients with exocrine pancreatic insufficiency]

To clarify the mechanism of the fat maldigestion in 9 patients with exocrine pancreatic insufficiency, lipase activities, pH, and micellar lipids in the upper small intestinal contents were studied. The upper small intestinal pH was slightly less in patients with exocrine pancreatic insufficiency than in healthy controls. Lipase activities and micellar lipids were significantly reduced in patients with exocrine pancreatic insufficiency compared with in healthy controls. There was a significant correlation between serum cholesterol and micellar cholesterol concentrations. The results suggest that there is maldigestive state in the digestion-absorption process in patients with exocrine pancreatic insufficiency due to insufficiency of lipase secretion and that insufficiency of lipase secretion disturbs hydrolysis of triglyceride and prevents micelle formation and leads to reduced uptake of cholesterol into micellar phase and it is reflected in serum cholesterol.

Clinical efficacy of fluvastatin for hyperlipidemia in Japanese patients

The objective of the study was to evaluate the efficacy and safety of fluvastatin in patients with hypercholesterolemia, including heterozygous familial hypercholesterolemia, in a 1-year study (a 12-week open assessment, followed by 40 weeks of active treatment). Of the 337 patients enrolled in the study, the effects of fluvastatin were analyzed in 296 patients at baseline and at 12 weeks. Of these, 265 were receiving 20 mg/day fluvastatin at week 12 and in 20 patients the dose had been increased to 30 mg/day; 11 patients violated the dosing protocol. A total of 229 patients continued into the 40-week, long-term phase, and 212 patients were analyzed at baseline and after 24 and 52 weeks. At the end of treatment, 153 evaluable patients were still taking 20 mg/day fluvastatin, 1 was taking 10 mg/day, and 48 patients were taking 30 mg/day, and 10 were taking 40 mg/day. In the 20 mg/day fluvastatin group, low density lipoprotein cholesterol (LDL-C) levels decreased by 24.1% at week 12 and by 29.3% at week 52. In those patients requiring the higher doses, the corresponding reductions in LDL-C were 20.2% (week 12) and 26.7% (week 52). Total cholesterol was also reduced at week 12 by 17.0% (20 mg/day) and 15.7% (20-30 mg/day), and at week 52 by 20.4% (< or = 20 mg/day) and 19.2% (> or = 30 mg/day). Throughout the study, fluvastatin was generally well tolerated and no serious clinical adverse events were observed. In conclusion, long-term treatment of hypercholesterolemia with fluvastatin at dosages of 20-40 mg daily can be considered both safe and effective.

Relationship between insulin-dependent diabetes mellitus (IDDM) and non-insulin-dependent diabetes mellitus: beta-cell function, islet cell antibody, and haptoglobin in parents of IDDM patients

To examine the relationship between non-insulin-dependent diabetes mellitus (NIDDM) and insulin-dependent diabetes mellitus (IDDM), we studied beta-cell function, HLA type, and serologic markers of IDDM and NIDDM in the parents of IDDM patients. Fifty-two parents of 33 IDDM patients were examined in terms of islet-cell antibody (ICA) status, haptoglobin phenotype, HLA type, and insulin responses during an oral glucose tolerance test (OGTT). Twenty-seven parents were prospectively evaluated for up to 113 months. They were divided into the following three groups based on pattern of ICA positivity during the follow-up period: group 1, persistently positive ICA (n = 4); group 2, fluctuating ICA (n = 7); and group 3, persistently negative ICA (n = 16). Twenty-three percent (12 of 52) of the parents of IDDM patients had NIDDM, and 12% (six of 52) of the matched controls did. The prevalence of ICA in the parents (11 of 52, 21%) was greater than in normal controls (one of 112, P < .01). Diabetic parents tended to show a higher prevalence of ICA (six of 12, 50%) than nondiabetic parents (six of 40, 15%; P = .06). ICA-positive parents showed higher glucose levels and lower insulin responses than ICA-negative parents. Three of four parents in group 1 slowly progressed to an insulin-dependent state during 25 +/- 3 months of follow-up evaluation. Parents in group 2 and group 3 did not show any changes in glucose levels or insulin responses during the study.(ABSTRACT TRUNCATED AT 250 WORDS)

[Contribution of carbohydrate antigens to endothelial E-selectin binding in cancer cells]

We first investigated the difference in carbohydrate antigens' expression between primary tumors and matched metastatic liver lesions of colorectal carcinomas, using immunohistochemical methods. Regarding the degree of expression, SLA, SLX and SPan-1 antigens were found to be expressed on a larger proportion of tumor cells in liver metastases than in primary tumors. Second, comparing the expression of carbohydrate antigens on highly metastatic colon cancer cell line to the parental line, the expression of SLA on the surface of highly metastatic variant was increased more intensively than the parental line. Finally, we investigated the contribution of carbohydrate antigens to endothelial E-selectin binding in colon and pancreatic cancer cells, and the results indicated that SLA might play a significant role in this binding. These findings suggest that the expression of carbohydrate antigens on the surface of cancer cells obviously contributed to E-selectin binding and also to metastatic potential.

NBQX, a selective antagonist of the AMPA receptor, affects neither field potentials nor long-term potentiation in vivo

NBQX (2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline), a selective antagonist of AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate) receptors, at an anticonvulsant dose of 40 mg/kg (i.p.), was shown in vivo to have no effects on either the field potentials in the piriform cortex or those in the dentate gyrus of the hippocampus. The same dose of NBQX also exerted no significant effects on long-term potentiation in the hippocampus. These results suggest that the mechanism underlying the anticonvulsant action of NBQX in vivo does not involve a suppressive action on physiological synaptic transmission. The possible clinical usefulness of AMPA receptor antagonists as antiepileptic drugs is suggested.

Clinical and chronobiological effects of light therapy on nonseasonal affective disorders

Light therapy (bright or dim light) was given at different times (morning or evening) to 27 unmedicated patients with nonseasonal depression (according to DSM-III-R criteria) and 16 normal volunteers. Circadian rhythms in body temperature were measured before and after light therapy. Bright light significantly improved clinical symptoms of depression, as measured by the Hamilton Rating Scale for Depression (HRSD), independent of the time of phototherapy. Dim light therapy had no effect on HRSD scores. Circadian rhythms of body temperatures in patients with affective disorder were more sensitive to the entraining effects of bright light than those of normal subjects, but these effects were not related to clinical improvement. Bright light exposure has an antidepressant effect on patients with nonseasonal depression, but the effect is unlikely to be mediated via the same circadian system that regulates body temperature.

Inhibition of restenosis by beraprost sodium (a prostaglandin I2 analogue) in the atherosclerotic rabbit artery after angioplasty

We examined the effect of beraprost sodium (BPS), a stable prostaglandin I2 (PGI2) analogue, on restenosis after balloon angioplasty in the atherosclerotic artery in rabbits. Regional atherosclerosis was induced in the femoral artery of New Zealand white rabbits by balloon deendothelialization and 2% cholesterol diet. After establishment of atheroma in the femoral artery, angioplasty was performed. In all, 65 rabbits were assigned to the following six subcutaneous drug treatment groups: control group (n = 13, saline 0.25 ml/kg); BPS low-dose group (n = 11, BPS 50 micrograms/kg twice daily); BPS high-dose group (n = 12, BPS 100 micrograms/kg twice daily); 2-day BPS high-dose group (n = 11, BPS 100 micrograms/kg twice daily for 2 days after angioplasty); aspirin (ASA) group (n = 10, ASA 30 mg once daily); and BPS+ASA group (n = 8, BPS 50 micrograms/kg twice daily plus ASA 30 mg once daily). Administration of each drug was started 30 min before balloon angioplasty and was continued until 4 weeks thereafter, except in the 2-day BPS high-dose group. Re-examination 4 weeks after the angioplasty showed significant (p < 0.05) preservation of the luminal diameter in the BPS high-dose and 2-day BPS high-dose groups (1.30 +/- 0.15 and 1.25 +/- 0.09 mm, respectively) as compared with that in the control group (0.83 +/- 0.10 mm); however, the luminal diameter in the BPS low-dose, ASA, and BPS+ASA groups (0.94 +/- 0.18, 1.06 +/- 0.11, and 1.05 +/- 0.15 mm, respectively) was not significantly different from that in the control group.

[Role of carbohydrate antigens in cell-cell and cell to extracellular matrix adhesion on pancreatic cancer]

We investigated the variable adhesiveness of pancreatic cancer cells by glycosylation inhibitor to elucidate the role of carbohydrate antigens in cell-cell and cell to extracellular matrix adhesion. Various carbohydrate antigens were strongly expressed on pancreatic cancer cell (SW1990) by ELISA, and these expression correlated to its in vitro invasiveness and in vivo metastatic potential. Cellular adhesion to Matrigel, laminin and collagen type IV and homotypic cellular aggregation in SW1990 were enhanced by reducing O-linked glycosylation with its inhibitor (Bzl-GalNAc), and these effect were reversed by additional purified mucins. These results suggested that O-linked glycoproteins on SW1990 cell surface may inhibit its adhesiveness to the substratum and aggregation properties by hindering surface receptors, and this variability of adhesiveness induced by altered glycosylation may have an another important role in highly metastatic potential of well glycosylated cancer cells.

[The changes in nuclear DNA content in acquisition of a high capacity for metastasis of human cell lines]

Quantification of nuclear DNA content in cancer is considered a prognostic factor, and several investigators have demonstrated that aneuploid tumors are more aggressive than diploid tumors. In this report, we investigated the relationship between metastatic capacity and nuclear DNA content using gastric and colon cancer cell lines. We established a highly peritoneal metastatic cell line (2M-D3) from a gastric cancer cell line (2M) and a highly liver metastatic cell line (LM-H3) from colon cancer cell line (LM) in our laboratory. Both the highly metastatic cell lines have more capacity for growth and metastasis, but lower nuclear DNA content and chromosome numbers than these parental cell lines. The results indicated that metastatic capacity was inversely proportional to nuclear DNA content. We cannot provide a satisfactory explanation for this inverse correlation between metastatic capacity and nuclear DNA content, but it is supposed that each cancer cell may have suitable and stable nuclear DNA content in metastasis.

Effect of ultraviolet-A (UV-A) light on growth, photosynthetic activity and production of biopterin glucoside by the marine UV-A resistant cyanobacterium Oscillatoria sp

We have isolated a marine planktonic cyanobacterium Oscillatoria sp. NKBG 091600 which is resistant to ultraviolet-A (UV-A) irradiation. In response to UV-A irradiation this cyanobacterium produces high levels of a UV-A absorbing compound which was identified previously as biopterin glucoside. Here, we have investigated the effect of UV-A light intensity on growth, biopterin glucoside production and photosynthetic activity. Oscillatoria sp. NKBG 091600 could grow at UV-A intensities of up to 800 microW/cm2 and at 300 microW/cm2 could grow as well as in the absence of UV-A irradiation. In addition, pre-culture of cells with UV-A protected cells from UV-A induced inhibition of photosynthetic activity. Detection of biopterin glucoside levels in irradiated cells by HPLC demonstrated that after 10 h there was a rapid increase in biopterin glucoside content. This increase was dependent on the intensity on the intensity of the UV-A irradiation.

Differential expression of type 2 and type 3 inositol 1,4,5-trisphosphate receptor mRNAs in various mouse tissues: in situ hybridization study

The inositol 1,4,5-trisphosphate receptor (IP3R) is an intracellular Ca2+ release channel responsible for mobilizing stored Ca2+. Three different receptor types have been molecularly cloned, and their genes have been classified into a family. The gene for the type 1 receptor (IP3R1) is predominantly expressed in cerebellar Purkinje neurons, but its gene product is localized widely in a variety of tissues; however, there is little information on what types of cells express the other two receptor types, type 2 and type 3 (IP3R2 and IP3R3, respectively). We studied the expression of the IP3R gene family in various mouse tissues by in situ hybridization histochemistry. Compared with IP3R1, the levels of expression of IP3R2 and IP3R3 mRNAs were low in all of the tissues tested. IP3R2 mRNA was localized in the intralobular duct cells of the submandibular gland, the urinary tubule cells of the kidney, the epithelial cells of epididymal ducts and the follicular granulosa cells of the ovary, while the IP3R3 mRNA was distributed in gastric cells, salivary and pancreatic acinar cells and the epithelium of the small intestine. All of these cells which express either IP3R2 or IP3R3 mRNA are known to have a secretory function in which IP3/Ca2+ signalling has been shown to be involved, and thus either IP3R2 or IP3R3 may be a prerequisite to secretion in these cells.

Role of SPan-1 antigen in adhesion of human colon cancer cells to vascular endothelium

Recently E-selectin (ELAM-1, endothelial leukocyte adhesion molecule-1) was shown to recognize not only sialyl Lewis X but also sialyl Lewis A, and these carbohydrate antigens may be involved in the process of the adhesion between cancer cells and endothelial cells in cancer metastasis. To investigate the contribution of sialylated carbohydrate antigen, SPan-1, and sialic acid to the adhesion of human colon cancer cells to endothelial cells, adhesion assay using HUVECs (human umbilical vein endothelial cells) was performed. The adhesion was significantly inhibited by pretreatment with anti-E-selectin antibody, indicating that this adhesion was thought to be mediated by E-selectin. When these cancer cells were pretreated with SPan-1 antibody, the adhesion was significantly inhibited in a concentration-dependent manner. The adhesion was also inhibited by pretreatment with neuraminidase. These findings suggest that the SPan-1 antigen plays a significant role in the adhesion of human colon cancer cells to endothelial cells, and sialylation of the terminal structure of carbohydrate antigens is important in this adhesion.

Overexpression of apolipoprotein E prevents development of diabetic hyperlipidemia in transgenic mice

To determine the role of apolipoprotein E (apoE) in diabetic hyperlipidemia, we induced diabetes in transgenic mice overexpressing apoE by intravenous injection of streptozotocin (STZ) and examined plasma lipoprotein metabolism in these mice. In STZ-induced diabetic mice, blood glucose levels were > 19 mmol/l (350 mg/dl) and plasma insulin levels were reduced to < 5 pmol/l (1 microU/ml). The diabetic nontransgenic mice developed hypercholesterolemia (plasma total cholesterol level: 4.55 +/- 1.32 vs. 1.97 +/- 0.13 mmol/l [176 +/- 51 vs. 76 +/- 5 mg/dl]) and hypertriglyceridemia (plasma triglyceride level: 0.82 +/- 0.29 vx. 0.42 +/- 0.11 mmol/l [73 +/- 26 vs. 37 +/- 10 mg/dl]) compared with values before induction of diabetes. In the diabetic nontransgenic mice, enhanced intestinal acylCoA:cholesterol acyltransferase activity was demonstrated, a factor that may contribute to the development of diabetic hyperlipidemia. Induction of apoE remarkably reduced the development of hyperlipidemia in diabetic transgenic mice compared with diabetic nontransgenic mice (plasma cholesterol level: 4.55 +/- 1.32 vs. 3.31 +/- 0.47 mmol/l [176 +/- 51 vs. 128 +/- 18 mg/dl], P < 0.01, and plasma triglyceride level: 0.82 +/- 0.29 vs. 0.17 +/- 0.11 mmol/l [73 +/- 26 vs. 15 +/- 10 mg/dl], P < 0.01). Plasma lipoprotein analysis by gel filtration chromatography showed that the reduction of plasma cholesterol and triglyceride levels was due to the disappearance of lipoproteins containing apoB. In these studies, we demonstrated the usefulness of STZ-induced diabetes in mice as an animal model for diabetic hyperlipidemia and demonstrated that endogenous induction of apoE in transgenic mice improved diabetic hyperlipidemia.