Secondary reconstruction of a mobile eye socket 30 years after enucleation of the eyeball for retinoblastoma: a case report.

A mobile eye socket is generally reconstructed by inserting an implant into the scleral pocket immediately after bulbar exenteration, or by attaching the extra-ocular muscles to the implanted artificial eyeball immediately after enucleation. However, exposure of the implanted material and other problems can occur. We achieved satisfactory reconstruction of a mobile eye socket by using an autogenous cartilage graft and a pericranial flap in a patient with long-standing anophthalmia due to enucleation. This case is presented with a review of the relevant literature.

Coronary revascularization in Japan. Part 1: survey of facilities during 1997.

Coronary artery disease is one of the major causes of morbidity and mortality in industrialized countries, including Japan. Increasing numbers of patients have been treated with percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG), but there is little information in Japan concerning the use of revascularization therapy and the facilities. The Japanese Coronary Intervention Study (JCIS) Group conducted a nationwide survey on coronary revascularization procedures and facilities during 1997. A questionnaire was mailed to the presidents or designated delegates of 8,253 laboratories in 7,986 hospitals that had departments of internal medicine and/or cardiovascular medicine and to 578 facilities in 558 hospitals identified by the PCI survey as performing CABG and/or registered in the annual survey carried out by the Japanese Association for Thoracic Surgery. A total of 109,788 PCIs were performed at 1,023 laboratories, and 17,667 CABGs at 477 facilities. PCI and CABG numbers per 10(6) population were 870 and 140, respectively. The ratio of PCI to CABG was 6.2. The numbers of PCI laboratories and CABG facilities per 10(6) population were 8.1 and 3.8, respectively. The majority of PCI laboratories and CABG facilities had a small annual volume: 44% of PCI laboratories and 77% of CABG facilities had annual volumes of 50 or less. Only half of the PCI laboratories had surgical backup on-site. Despite the small volume for each facility, coronary revascularization, especially PCI, is highly utilized in Japan.

Coronary revascularization in Japan. Part 2: comparison of facilities between 1997 and 1999.

A nation-wide survey on the procedures and facilities of coronary revascularization, percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) conducted by the Japanese Coronary Intervention Study (JCIS) group during 1997 revealed that PCI is more often used than CABG and is mainly carried out in low-volume facilities without surgical backup. The present study aimed to investigate the temporal changes in the usage of revascularization therapies and facilities from 1997 to 1999. A questionnaire was mailed in 1998 to the delegates of 1,086 PCI and 582 CABG facilities identified by the previous survey, and 89% of PCIs surveyed and 94% of CABGs surveyed reported back. The number of PCI procedures had increased by 19% from 97,831 to 116,479 and that of CABG procedures also increased by 21% from 16,374 to 19,846. The ratio of PCI to CABG was 5.9 in 1999, showing no significant change from 6.0 in 1997. In parallel, the number of PCI and CABG facilities increased from 888 to 941 and from 442 to 453, respectively. The use of coronary stents and other interventional devices increased during these 2 years. Coronary stents were used regardless of the annual procedural volume of the facilities, whereas other interventional devices, directional and rotational coronary atherectomy, were used mainly in the high-volume laboratories (p<0.01). Beating-heart, off-pump CABG had increased from 2% to 11% of total cases. Continued monitoring of trends in PCI and CABG facilities and procedures will be needed for nation-wide assessment of the use of new technology.

Retinoic acid-induced tissue transglutaminase and apoptosis in vascular smooth muscle cells.

Retinoids exert antiproliferative and prodifferentiating effects in vascular smooth muscle cells (SMCs) and reduce neointimal mass in balloon-injured blood vessels. The mechanisms through which retinoids carry out these effects are unknown but likely involve retinoid receptor-mediated changes in gene expression. Here we report the cloning, chromosomal mapping, and biological activity of the retinoid-response gene rat tissue transglutaminase (tTG). Northern blotting studies showed that tTG is rapidly and dose-dependently induced in a protein synthesis-independent manner after stimulation with the natural retinoid all-trans retinoic acid (atRA). The induction of tTG was selective for atRA and its stereoisomers 9-cis and 13-cis RA, because little or no elevation in mRNA expression was observed with a panel of growth factors. Western blotting and immunofluorescence confocal microscopy showed an accumulation of cytosolic tTG protein after atRA stimulation. Radiolabeled cross-linking studies revealed a corresponding elevation in in vitro tTG activity. The increase in tTG activity was reduced in the presence of 2 distinct inhibitors of tTG (monodansylcadaverine and cystamine). atRA-induced tTG mRNA and protein expression were followed by a significant elevation in SMC apoptosis. Such retinoid-induced programmed cell death could be partially inhibited with each tTG inhibitor and was completely blocked when both inhibitors were used simultaneously. These results establish a role for atRA in the sequential stimulation of tTG and apoptosis in cultured SMCs. atRA-mediated apoptosis in SMCs seems to require the participation of active tTG, suggesting a potential mechanistic link between this retinoid-inducible gene and programmed cell death.

Surgical resection of cerebral arteriovenous malformation combined with pre-operative embolisation.

To assess the importance of pre-operative embolisation, 27 cases of cerebral artriovenous malformation (AVM) treated in this institute between July 1994 and October 1998 were analysed. The patients' ages ranged from 3 to 70 years (average 36.9) with a follow-up period of 1-41 months (average 19.2). The patient presented with haemorrhage in 21 cases and seizure in five. In 21 of 27 cases, surgical resection of a nidus was performed, gamma knife therapy was applied in three and conservative therapy was chosen in three. Of 21 cases treated surgically, total removal was achieved in 19 cases and a residual nidus was seen in one (a large basal ganglia AVM). In the remaining case, postoperative angiography was not available. Pre-operative embolisation followed by surgical resection of the nidus was performed in seven cases in which there was a large AVM. A volume index was calculated to indicate the size of the nidus using X x Y x Z, where X is the maximum diameter (cm) of the nidus on the lateral angiogram, Y is the diameter (cm) perpendicular to X and Z is the maximum diameter (cm) on the anteroposter or angiogram. The index averaged 45.9 for the cases in which pre-operative embolisation was performed, while it was 5.6 in the cases without embolisation. Pre-operative embolisation was performed to reduce the nidus flow as much as possible, to prevent overload to the surrounding structures. At surgery, the nidus was resected from the surrounding tissue and care was taken not to enter the nidus. Postoperatively, the systolic blood pressure was maintained at 90-100 mmHg for several days in the intensive care unit. The results were excellent in 15 cases, good in three (hemiparesis due to the initial haemorrhage remained in all three), fair in one (a patient with a severe subarachnoid haemorrhage). Two patients died (acute pulmonary oedema and severe meningitis). Minor postoperative bleeding or oozing was seen in three cases. In conclusion, reducing the shunt flow through a nidus in a step-wise fashion with pre-operative embolisation of a large AVM seems to be quite helpful in preventing postoperative haemodynamic overload to the surrounding brain. It is also important not to enter the nidus when it is removed at surgery. This helps to prevent intraoperative and/or postoperative bleeding, and led to successful total removal of the nidus with a good postoperative course.

Angiotensin in the nucleus tractus solitarii contributes to neurogenic hypertension caused by chronic nitric oxide synthase inhibition.

Activation of the sympathetic nervous system and renin-angiotensin system has been suggested to contribute to the hypertension caused by chronic nitric oxide synthase inhibition. The aim of the present study was to determine whether angiotensin within the nucleus tractus solitarii (NTS) plays a role in activation of the sympathetic nervous system in this model. Rats were treated with N(omega)-nitro-L-arginine methyl ester (L-NAME, 100 mg. kg(-1). d(-1) in drinking water) for 2 weeks. Experiments were performed on anesthetized rats with denervated arterial and cardiopulmonary baroreceptors. Arterial pressure, heart rate, and renal sympathetic nerve activity (RSNA) were measured. Microinjection of an angiotensin II type 1 (AT(1)) receptor antagonist (CV11974) or an angiotensin II type 2 (AT(2)) receptor antagonist (PD123319) into the depressor region within the NTS (identified by prior injection of L-glutamate) was performed. Microinjection of CV11974, but not of PD123319, produced greater decreases in arterial pressure, heart rate, and RSNA in L-NAME-treated rats than in control rats. The administration of hexamethonium resulted in a larger fall in arterial pressure in L-NAME-treated rats than in control rats. The ACE mRNA level in the brain stem was greater in L-NAME-treated rats than in control rats. These results suggest that increased sympathetic nerve activity plays a role in hypertension caused by chronic nitric oxide synthase inhibition and that activation of the renin-angiotensin system in the NTS is involved at least in part in this increased sympathetic nerve activity via AT(1) receptors.

Non-ruptured large dorsal internal carotid artery aneurysm presenting with temporal quadrantanopsia.

A 63-year-old woman presenting with temporal lower quadrantanopsia of the right eye was found to have a large dorsal internal carotid artery aneurysm. Large dorsal aneurysms of the internal carotid artery are rare. Lateral compression of the optic nerve by the aneurysm might damage the optic nerve at the medial side of the right optic foramen. Direct clipping surgery was performed uneventfully. Since the dome of the aneurysm was buried in the frontal lobe and also attached to the anterior skull base, a careful approach to the aneurysm with removal of the anterior clinoid process and drilling into the planum sphenoidale around the aneurysm dome was needed. The surgical strategy is discussed.

Gene structure and chromosomal mapping of the rat smooth muscle calponin gene.

Smooth muscle cells (SMC) express a battery of lineage-restricted genes whose encoded proteins impart the unique contractile phenotype that characterizes this muscle type. While the encoded function of many SMC-restricted genes has been extensively analyzed, less is known about their position within the genome and the regulatory factors governing their transcription. In this report, we define the gene structure, 5' promoter analysis, and chromosomal mapping of the rat smooth muscle calponin (CnnI) gene. The rat CnnI gene is comprised of seven exons spanning approximately 8 kb of genomic sequence. The intron-exon boundaries of the rat CnnI gene match precisely those in human and mouse. Primer extension and RNase protection assays indicate two major transcription start positions (tsp). Comparative sequence analysis of the 5' promoter region reveals several conserved cis regulatory elements, including a TA-rich element within 30 nt of the tsp that could be a recognition site for TATA-binding protein and two CCAAT boxes. Transient and stable transfection studies support the hypothesis that distal regulatory elements confer SMC-restricted expression of CnnI. Finally, using an F2 intercross, we have mapped the rat CnnI gene to the telomeric end of Chromosome (Chr) 8. These studies provide additional information relating to the control of CnnI gene expression and provide a platform to begin assessing the potential linkage of CnnI to spontaneous and experimental disease phenotypes in rats.

BB rat diabetes susceptibility and body weight regulation genes colocalize on chromosome 2.

The genetic etiology of Type 1 (insulin-dependent) diabetes mellitus is complicated by the apparent presence of several diabetes susceptibility genetic regions. Type 1 diabetes in the inbred BioBreeding (BB) rat closely resembles the human disorder and was previously shown to involve two genes: the lymphopenia (lyp) region on Chromosome (Chr) 4 and RT1(u) in the major histocompatibility complex (MHC) on Chr 20. In addition, a segregation analysis of an F(2) intercross between the diabetes-prone congenic BB DR(lyp/lyp, u/u) and F344(+/+,)(lv/lv) rats indicated that at least one more genetic factor was responsible for Type 1 diabetes. In this study, we generated F(2)N(2) progeny in a cross between non-diabetic F(2)(DR(lyp/lyp,u/u) x F344)(lyp/lyp,u/u) and diabetic DR(lyp/lyp, u/u) rats. In a subsequent total genome scan, a third factor was mapped to the 21.3-cM region on Chr 2 between D2Mit14 and D2Mit15 (peak LOD score 4.7 with 67% penetrance). Interestingly, the homozygosity of the BB allele (b/b) for the Chr 2 region was significantly associated with a greater weight reduction after fasting than the homozygosity of the F344 allele (f/f, p < 0.008). In conclusion, the development of Type 1 diabetes in the congenic DR(lyp/lyp) rat is controlled by at least three genes: lymphopenia, MHC, and a third factor that may play a role in metabolism and body weight regulation.

Identification of a novel inflammation-protective locus in the Fischer rat.

Inbred LEW/N rats are relatively susceptible, while histocompatible inbred F344/N rats are relatively resistant to development of a wide variety of inflammatory diseases in response to a range of pro-inflammatory stimuli. In a LEW/N vs. F344/N F2 intercross, we identified a quantitative trait locus (QTL) on Chr 10 that protects in a dominant fashion against the exudate volume component of innate inflammation in the F344/N rat, as well as a suggestive QTL on Chr 2 near the Fibrinogen cluster region. The exudate volume linkage region on Chr 10 may be similar to one of the multiple regions found to link to inflammatory arthritis phenotypes in other crosses. The suggestive linkage on Chr 2 has not been previously reported and does not seem to contribute to this phenotype in the same manner as the QTL on Chr 10. These findings are consistent with the hypothesis that the innate exudate volume trait is a sub-phenotype of more complex inflammatory phenotypes, such as arthritis, and genes within the Chr 10 linkage region could account for differences in this non-specific acute phase component of the inflammatory response. Since the rat Chr 10 exudate volume linkage region we have identified is syntenic with a region of human Chr 17 that has been shown to link to a variety of autoimmune/inflammatory diseases, including insulin-dependent diabetes mellitus, multiple sclerosis, and psoriasis, identification of genes within this linkage region will shed light on genes relevant to the earliest inflammatory component and to susceptibility and resistance to such human autoimmune/inflammatory diseases.

Mapping and characterization of quantitative trait loci for non-insulin-dependent diabetes mellitus with an improved genetic map in the Otsuka Long-Evans Tokushima fatty rat.

The Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an animal model for obese-type, non-insulin-dependent diabetes mellitus (NIDDM) in humans. We have previously reported four quantitative trait loci (QTLs) responsible for NIDDM on Chromosomes (Chrs) 7, 14, 8, and 11 (Nidd1-4/of for Non-insulin-dependent diabetes1-4/oletf) by a whole-genome search in 160 F2 progenies obtained by mating the OLETF and the Fischer-344 (F344) rats. Our present investigation was designed to identify and characterize novel QTLs affecting NIDDM by performing a genome-wide linkage analysis of genes for glucose levels and body weight and analysis for gene-to-gene and gene-to-body-weight interactions on an improved genetic map with a set of 382 informative markers in the 160 F2 progenies. We have identified seven novel QTLs on rat Chrs 1 (Nidd5 and 6/of), 5 (Nidd7/of), 9 (Nidd8/of), 12 (Nidd9/of), 14 (Nidd10/of) and 16 (Nidd11/of) which, together with the Nidd1-4/of, account for a total of approximately 60% and approximately 75% of the genetic variance of the fasting and postprandial glucose levels, respectively, in the F2. While the OLETF allele corresponds with increased glucose levels as expected for the novel QTLs except Nidd8 and 9/of, the Nidd8 and 9/of exhibit heterosis: heterozygotes showing significantly higher glucose levels than OLETF or F344 homozygotes. There are epistatic interactions between Nidd1 and 10/of and between Nidd2 and 8/of. Additionally, our results indicated that the Nidd6 and 11/of could also contribute to an increase of body weight, and that the other five QTLs could show no linkage with body weight, but Nidd8,9, and 10/of have an interaction with body weight.

Identification of quantitative trait loci for non-insulin-dependent diabetes mellitus that interact with body weight in the Otsuka Long-Evans Tokushima Fatty rat.

Non-insulin-dependent diabetes mellitus (NIDDM) is a prototypical multifactorial disease. Genetic predisposition and obesity are major risk factors for NIDDM development and the interactions between these factors are likely to be important in the etiology of this disease. The Otsuka Long-Evans Tokushima Fatty (OLETF) rat is one of the best animal models of NIDDM, since the OLETF rat develops NIDDM with mild obesity that is very similar to human NIDDM. Therefore, the OLETF rat is a powerful model for investigating the interaction between genetic susceptibility to NIDDM and obesity. In this study, our goal was to clarify the relationship between an individual NIDDM susceptibility locus and obesity in the OLETF using a molecular genetics approach. We identified four novel quantitative trait loci (QTLs) that contribute to the susceptibility to NIDDM, none of which shows significant linkage with body weight. However, Nidd1/of on chromosome 7 and Nidd2/of on chromosome 14 have an interaction with body weight. In contrast, one locus was mapped to chromosome 10 for body weight, but not to fasting or postprandial glucose levels. These data illustrate that NIDDM and body weight are under separate genetic control in the OLETF yet interact to yield the final disease phenotype in the two Nidd/of loci. In addition, body weight could be used in place of body mass index as an indicator of obesity in our experimental system of genetic study. This study will facilitate the understanding of the complex interaction between genetic susceptibility to NIDDM and obesity.

Gene-based anchoring of the rat genetic linkage and cytogenetic maps: new regional localizations, orientation of the linkage groups, and insights into mammalian chromosome evolution.

In order to generate anchor points connecting the rat cytogenetic and genetic maps, the cytogenetic position of 62 rat markers (including 55 genes) already localized genetically was determined by fluorescence in situ hybridization. Whenever possible, markers located near one end of the linkage groups were included. These new localizations allowed us to unambiguously orient the 20 autosomal and the X chromosome linkage groups. The position of the centromere in the linkage map could also be determined in the case of several metacentric chromosomes. In addition, the regional localization of 15 other rat genes was determined. These new data bring useful information with respect to comparative mapping with the mouse and the human and to mammalian evolution. They illustrate, for instance, that groups of genes can remain syntenic during mammalian evolution while being subjected to intrachromosomal rearrangements in some lineages (synteny is conserved while gene order is not). This analysis also disclosed cases of synteny conservation in one the two rodent species and the human, while the synteny is split in the other rodent species: such configurations are likely examples of lineage-specific interchromosomal rearrangements associated with speciation.

An integrated genetic linkage map of the laboratory rat.

The laboratory rat, Rattus novegicus, is a major model system for physiological and pathophysiological studies, and since 1966 more than 422,000 publications describe biological studies on the rat (NCBI/Medline). The rat is becoming an increasingly important genetic model for the study of specific diseases, as well as retaining its role as a major preclinical model system for pharmaceutical development. The initial genetic linkage map of the rat contained 432 genetic markers (Jacob et al. 1995) out of 1171 developed due to the relatively low polymorphism rate of the mapping cross used (SHR x BN) when compared to the interspecific crosses in the mouse. While the rat genome project continues to localize additional markers on the linkage map, and as of 11/97 more than 3,200 loci have been mapped. Current map construction is using two different crosses (SHRSP x BN and FHH x ACI) rather than the initial mapping cross. Consequently there is a need to provide integration among the different maps. We set out to develop an integrated map, as well as increase the number of markers on the rat genetic map. The crosses available for this analysis included the original mapping cross SHR x BN reciprocal F2 intercross (448 markers), a GH x BN intercross (205 markers), a SS/Mcw x BN intercross (235 markers), and a FHH/Eur x ACI/Hsd intercross (276 markers), which is also one of the new mapping crosses. Forty-six animals from each cross were genotyped with markers polymorphic for that cross. The maps appear to cover the vast majority of the rat genome. The availability of these additional markers should facilitate more complete whole genome scans in a greater number of strains and provide additional markers in specific genomic regions of interest.

Regional time-dependent changes in vasopressin V2 receptor expression in the rat kidney during water restriction.

Elevations of arginine vasopressin (AVP) binding to renal vasopressin V2 receptors (V2R) enhance water and urea reabsorption in the collecting duct epithelium. This study was designed to quantify the levels of V2R mRNA and protein within the distinct regions of the Sprague-Dawley rat kidney (i.e., the cortex and outer and inner medulla) during 24 and 48 h of water restriction. A competitive reverse transcription-polymerase chain reaction (RT-PCR) assay was developed to quantify changes in the V2R mRNA, in which a deletion mutant RNA transcript was used to control for the efficiency of RT-PCR. Western blot analysis was utilized for the quantification of the V2R protein. The results showed that the steady-state levels of the V2R mRNA decreased in a time-dependent manner in the cortex and outer and inner medulla throughout 48 h of water restriction. Western blot analysis revealed that the V2R protein in the renal cortex decreased after the initial 24 h of water restriction and remained decreased at 48 h. In contrast, outer medullary V2R protein decreased significantly only after 48 h of water restriction, whereas no significant change in the inner medullary V2R protein was observed throughout the 48 h of water restriction. These results suggest that water restriction leads to a regional time-dependent downregulation of the V2R mRNA and protein within the rat kidney. The stability of the plasma membrane V2R protein within the inner medulla may allow for the optimization of urine concentration and minimize water loss during periods of water restriction.