Differential expression of XAP5, a candidate disease gene

We have isolated a full-length cDNA corresponding to the XAP5 gene in Xq28. An unusual feature of the cDNA is that it contains runs of CCG repeats in the 5' untranslated region, typical of genes that exhibit anticipation. It has a striking pattern of differential expression and is greatly enhanced in various fetal tissues. This predicted protein encodes a unique 339-amino-acid polypeptide that contains a large percentage of highly charged residues and a possible nuclear localization signal. A comparison to genomic sequence shows that XAP-5 comprises 13 exons spanning 6.5 kb. An examination of the human population indicates that the longest CCG run is polymorphic and varies in length from 8 to 12 repeats.

Prohormone convertase 2 is necessary for the formation of cholecystokinin-22, but not cholecystokinin-8, in RIN5F and STC-1 cells

Two endocrine tumor cell lines from pancreas (RIN5F) and intestine (STC-1) express cholecystokinin (CCK) messenger RNA and are able to posttranslationally process pro-CCK to CCK-22 and CCK-8 amide. Both of these forms are also secreted by these cells. Because they make and secrete forms of amidated CCK larger than CCK-8, they represent a model of pro-CCK processing in the gut and allow investigation of possible mechanisms for tissue differences in prohormone processing. Both of these cells express two endoproteases convertase-1 (PC1) also known as PC3 and prohormone convertase-2 (PC2), which may be involved in pro-CCK processing. We have previously shown than inhibition of PC1 expression in these cells using stable expression of antisense messenger RNA caused a significant reduction in cellular content of amidated CCK and caused a selective depletion of CCK-8 with a comparative sparing of CCK-22. We demonstrate here that inhibition of PC2 expression in these cells also caused a large initial decrease in CCK content and produced a selective depletion of CCK-22 and a comparative sparing of CCK-8. These results support both a role for both PC1 and PC2 in pro-CCK processing in these cells and the hypothesis that tissue-specific processing of pro-CCK may be explained by differences in expression or activity of PC1 and PC2.

Analysis of the structure and expression fo the TFIIB gene in Drosophila melanogaster

We have isolated and characterized a genomic clone encoding the Drosophila melanogaster transcription factor IIB (TFIIB). The coding region of the TFIIB gene is interrupted by three short introns. The 5'-flanking region of the gene lacks the typical TATA box sequence like those of other known genes encoding the general transcription factors. In addition, the 5'-flanking region of the gene contains several common DNA sequences present in Drosophila TBP and TFIIS genes, suggesting the common regulation mechanism of gene expression. RNA blot analysis revealed that the gene expresses 1.6 kb, 1.3 kb and 1.2 kb mRNAs throughout development and in adults. Deletion analysis of the promoter region shows that the minimal promoter necessary for efficient expression is located between -698 (PstI) and +60 relative to the transcription start point. Within this minimal promoter region, the upstream regulatory element responsible for the stimulation of gene expression may exist in the DNA fragment between -698 (PsfI) and -351 (StuI).

Bilateral coronary arteriovenous fistula coexistent with atrial septal defect and pulmonary stenosis

A coronary arteriovenous fistula consists of a communication between a coronary artery and a cardiac chamber, a great artery or the vena cava. It is the most common anomaly that can affect coronary perfusion. Bilateral involvement of coronary fistula, however, constitutes an uncommon subgroup of coronary arteriovenous fistulas. We report a case which shows a rare occurrence of bilateral coronary arteriovenous fistula coexistent with atrial septal defect and pulmonic stenosis.

Prohormone convertase 1 is necessary for the formation of cholecystokinin 8 in Rin5F and STC-1 cells

Several immortalized cell lines serve as models for procholecystokinin (pro-CCK) processing. Rin5F cells, derived from a rat insulinoma, and STC-1 cells, derived from a murine intestinal tumor, process pro-CCK mainly to amidated CCK 8. Both also make significant quantities of amidated CCK 22, a slightly larger form found in the gut. Many modifications are necessary during pro-CCK processing including cleavages performed by endoproteases, the identities of which are unknown. A candidate endoprotease is prohormone convertase 1 (PC1) also known as PC3, a Ca2+-dependent serine endoprotease of the subtilisin family. Constitutive expression of antisense PC1 message in stably transfected Rin5F cells resulted in a significant reduction of the cellular content of CCK 8 as measured by radioimmunoassay. Several affected cell lines displayed about 80% reduction in CCK content in early passages after transfection. Expression of antisense PC1 message in these cell lines resulted in a selective depletion of CCK 8 and a comparative sparing of CCK 22. The induction of antisense PC1 message within a single subclone of Rin5F cells using the Lac Switch system also resulted in a significant inhibition of CCK content. Expression of antisense PC1 message in a stably transfected STC-1 cell line also resulted in a decrease in CCK content and in PC1 protein expression, and the specific depletion of CCK 8 with comparative sparing of CCK 22. These observations support the hypothesis that PC1 is necessary for pro-CCK processing in Rin5F and STC-1 cells and suggests a role for PC1 endoprotease in the biosynthesis of CCK 8 in vivo.

Historical selection, amino acid polymorphism and lineage-specific divergence at the G6pd locus in Drosophila melanogaster and D. simulans

The nucleotide diversity across 1705 bp of the G6pd gene is studied in 50 Drosophila melanogaster and 12 D. simulans lines. Our earlier report contrasted intraspecific polymorphism and interspecific differences at silent and replacement sites in these species. This report expands the number of European and African lines and examines the pattern of polymorphism with respect to the common A/B allozymes. In D. melanogaster the silent nucleotide diversity varies 2.8-fold across localities. The B allele sequences are two-to fourfold more variable than the derived A allele, and differences between allozymes are twice as among B alleles. There is strong linkage disequilibrium across the G6pd region. In both species the level of silent polymorphism increases from the 5' to 3' ends, while there is no comparable pattern in level of silent site divergence or fixation. The neutral model is not rejected in either species. Using D. yakuba as an outgroup, the D. melanogaster lineage shows a twofold greater rate of silent fixation, but less than half the rate of amino acid replacement. Lineage-specific differences in mutation fixation are inconsistent with neutral expectations and suggest the interaction of species-specific population size differences with both weakly advantageous and deleterious selection.

Stability of fronto-orbital advancement in nonsyndromic bilateral coronal synostosis: a quantitative three-dimensional computed tomographic study

Fronto-orbital dysmorphology in nonsyndromic bilateral coronal synostosis includes frontal flattening, supraorbital recession, and ocular globe protrusion. Surgical advancement of the supraorbital region ("bandeau") is performed to correct these deformities. A retrospective analysis of 10 consecutive patients with nonsyndromic bilateral coronal synostosis was performed to assess the effect of two types of bandeau fixation at the nasion. The advanced bandeau was fixed medially at the nasion with a calvarial bone graft and polyglycolic acid sutures (bone graft/suture group, five patients) or with a microplate (plate group, five patients) and bilaterally at pterion with calvarial bone grafts and polyglycolic acid sutures (all patients). The cranio-orbital dysmorphology and the surgical results were studied using pre-, peri-, and post-operative three-dimensional computed tomographic (CT) data. Reformation, manipulation, editing, and quantitative measurements of the CT data were performed on a computer workstation and Analyze imaging program. Four measurements performed to evaluate the fronto-orbital morphology: the length:width ratio of anterior cranial fossa, ventral globe index, cornea position, and supraorbital rim lag. The ventral globe index assessed the degree of eyeball protrusion out of the orbit cavity. Measurements of the cornea position and supraorbital rim lag were performed on the longitudinal orbit projections of the CT data. Six normal skull CT scans were available for same measurement and comparison. Measurements of the preoperative fronto-orbital dysmorphology in bilateral coronal synostosis were significantly different from those of normal subjects. One year after the surgery, the length:width ratio of the anterior cranial fossa was normalized in both groups. The ventral globe index was improved but not normalized in both groups, whereas the cornea position and supraorbital rim lag were improved in the bone graft/suture group but were normalized in the plate group. Based on the quantitative data, the surgical outcomes in the plate group were significantly better than those in the bone graft/suture group. Major relapse of surgical advancement in the bone graft/suture group seemed to occur in perioperative period. In summary, at 1 year postoperatively, the bandeau advancement improved but did not entirely normalize the fronto-orbital dysmorphology of nonsyndromic bilateral coronal synostosis in either group. We conclude that plate rigid fixation at the nasion provides superior stability for bandeau advancement compared with bone graft/suture fixation.

Chelation-enhanced fluorescence chemosensing of Pb(II), an inherently quenching metal ion

Pb(II) ion serves as a quencher of anthracene fluorescence both intermolecularly and in intracomplex systems reported to date. The advantages of intensimetric analyses showing increasing signal require the design of mechanistically novel fluorescent chemosensors capable of yielding enhanced fluorescence upon chelation of inherently quenching metals. We synthesized both 2- and 9-derivatives of anthracene bearing the N-methylthiohydroxamate ligand, which is capable of quenching fluorescence in the uncomplexed form and which shows some selectivity for Pb(II). Complexation of the 2-derivative to Pb(II) results in rapid metal ion-catalyzed hydrolysis, rendering this compound useless as a sensor with real-time response. However, complexation of the 9-derivative with Pb(II) results in a 13-fold fluorescence increase, reversible upon dissociation of the metal ion. While blood lead analysis is a major potential application for fluorescent chemosensors, the present compound is insufficiently selective for this use.

Amino acid polymorphism and rare electrophoretic variants of G6PD from natural populations of Drosophila melanogaster

Identifying the amino acid changes responsible for electrophoretic variants is essential to understanding the significance of allozyme polymorphism in adaptation. The amino acid mutations responsible for the common G6PD allozyme polymorphisms in Drosophila melanogaster have been recently described. This study characterizes the amino acid changes associated with 11 rare electrophoretic G6PD variants. The 11 rare electrophoretic variants result from six independent amino acid mutations. The in vivo function of the rare variants was determined in an earlier study and most variants fell into one of two function classes. It is shown here that the function of the rare variants reflects the state of the Pro/Leu mutation responsible for the A/B allozyme polymorphism in each variant. Two mutations destabilize quaternary structure resulting in shifts from tetrameric dimeric alleles, and one of these also results in a variant with in vivo function intermediate to A and B. That mutation is an aspartic-acid-to-asparagine change that is two residues away from the Pro/Leu polymorphism responsible for the A/B dimertetramer quaternary shift. Structure-function relationships based on studies of human G6PD deficiency-associated mutations predict that these last two amino acid changes fall within the protein domain responsible for NADP binding.

Acquired cutis laxa associated with chronic urticaria

A 31-year-old man had cutis laxa after an urticarial eruption. He had no systemic manifestations. In urticarial lesions, elastolysis occurred only within the inflammatory infiltrate of neutrophils around the vessels and between the collagen bundles. In lax skin, elastolysis occurred throughout the entire dermis. Electron microscopic study showed a markedly decreased number of elastic fibers, with elastolysis most predominant near the inflammatory cells. These findings suggest that the neutrophil plays a significant role in the destruction of elastic fibers and subsequent development of cutis laxa.

Mutational analysis of a conserved motif of Agrobacterium tumefaciens VirD2

The VirD2 polypeptide from Agrobacterium tumefaciens, in the presence of VirD1, introduces a site- and strand-specific nick at the T-DNA borders. A similar reaction at the origin of transfer (oriT) of plasmids is essential for plasmid transfer by bacterial conjugation. A comparison of protein sequences of VirD2 and its functional homologs in bacterial conjugation and in rolling circle replication revealed that they share a conserved 14 residue segment, HxDxxx(P/u)HuHuuux [residues 126-139 of VirD2; Ilyina, T.V. and Koonin, E.V. (1992) Nucleic Acids Res. 20, 3279-3285]. A mutational approach was used to test the role of these residues in the endonuclease activity of VirD2. The results demonstrated that the two invariant histidine residues (H133 and H135) are essential for activity. Mutations at three sites, histidine 126, aspartic acid 128 and aspartic acid 130, that are conserved in a subfamily of the plasmid mobilization proteins, led to the loss of VirD2 activity. Aspartic acid at position 130, could be substituted with glutamic acid and to a much lesser extent, with tyrosine. In contrast, another conserved residue, asparagine 139, tolerated many different amino acid substitutions. The non-conserved residues, arginine 129, proline 132 and leucine 134, were also found to be important for function. Isolation of null mutations that map throughout this conserved domain confirm the hypothesis that this region is essential for function.

Mycobacterium tuberculosis infection in an orangutan (Pongo pygmaeus)

A respiratory disorder was noted in a 5-year-old female orangutan kept in the Yongin Farmland. Radiographically, multiple radiodense foci ranging from 2 to 6 mm diameter were seen throughout the lung lobes. Grossly, the thoracic cavity revealed a firm texture and grayish-pink discoloration of the left apical lung lobe. Histopathologically, multifocal areas of granulomatous pneumonia present the right and left apical lung lobes. Both primers from IS1081 and IS6110 targeting 196 bp and 245 bp respectively were used in polymerase chain reaction, Mycobacterium tuberculosis was isolated from liver and confirmed by polymerase chain reaction.

Molecular characterization of two Drosophila guanylate cyclases expressed in the nervous system

We have isolated, by interspecies hybridization, two classes of Drosophila cDNA each encoding a different guanylate cyclase (GC). One of them encodes an alpha subunit homolog of soluble GC, designated DGC alpha 1, and the other encodes a receptor-type GC, designated DrGC. The dgc alpha 1 cDNA encodes a protein of 676 amino acids and maps to 99B. In situ hybridization to adult tissue sections showed that dgc alpha 1 mRNA is found mainly in the cell bodies of the optic lobe, central brain, and thoracic ganglia. The DGC alpha 1 protein was also localized primarily to the nervous system by immunocytochemical staining, consistent with results of in situ hybridization. However, no detectable expression of this protein was found in the retina. The other class of cDNA, drgc, maps to 76C and encodes a 1525-amino acid protein displaying structural features similar to other known receptor-type guanylate cyclases. However, it has a C-terminal 430 amino acid region that has no homology to any known proteins. drgc RNA is expressed at low levels throughout development and in adult heads and bodies. In situ hybridizations to adult tissue sections showed that drgc mRNA is expressed in a wide range of tissues, including the optic lobe, central brain, thoracic ganglia, digestive tract, and the oocyte.

Isolation and characterization of the gene encoding the Drosophila melanogaster transcriptional elongation factor, TFIIS

We have characterized a genomic clone encoding the Drosophila melanogaster transcriptional elongation factor, TFIIS. The coding region of the TFIIS gene is interrupted by a short intron. The potential promoter region, deduced from the determination of the transcription start point (tsp), lacks distinct TATAAA or CCAAT box consensus sequences. Southern analysis and the in situ hybridization to chromosomes suggests that it is single-copy gene which is localized to the 35B region on the left arm of the second chromosome.

Fatal vascular involvement in systemic lupus erythematosus following epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita may be associated with various systemic diseases, including systemic lupus erythematosus. We describe the clinical and immunological findings in a 38-year-old women with epidermolysis bullosa acquisita and systemic lupus erythematosus. The epidermolysis bullosa acquisita preceded a dramatic flare of systemic lupus erythematosus and fatal cerebral vasculitis. If serologic evidence of lupus erythematosus develops during the course of epidermolysis bullosa acquisita, a thorough investigation is warranted to rule out potentially life-threatening systemic lupus erythematosus.

Torsade de pointes induced by terfenadine in a patient with long QT syndrome

Torsade de pointes is a form of polymorphic ventricular tachycardia that is associated with prolongation of the QT interval. Although torsade de pointes is found in many clinical settings, it is mostly drug induced. Similar problems have been described with nonsedating H1-receptor antagonists, such as astemizole and terfenadine. Terfenadine is a widely used antihistamine. The authors report a case of torsade de pointes in a patient with a possible congenital sporadic form of QT interval prolongation who was receiving a therapeutic dose of terfenadine.

Suprageneric classification of peptidoglycan group B actinomycetes by nucleotide sequencing of 5S ribosomal RNA

5S ribosomal RNA sequences were determined for thirteen actinomycetes mainly representatives with the rare group B type peptidoglycan. The primary and secondary structure of the resultant sequences were of the type characteristic of Gram-positive bacteria with DNA rich in guanine plus cytosine. The sequencing and associated chemotaxonomic data provide compelling grounds for classifying actinomycetes with a group B type peptidoglycan in a single family. The family Microbacteriaceae fam. nov. is proposed to accommodate actinomycetes classified in the genera Agromyces, Aureobacterium, Clavibacter, Curtobacterium and Microbacterium.

Fluorescent chemosensing of catechol and catecholamines in water

It has been known for almost 35 years that catechol complexes reversibly to boronic acids. We observe that 2-anthrylboronic acid complexes catechol in water with Kd 330 microM and concomitant 20-fold reduction in fluorescence intensity. L-DOPA and dopamine behave similarly, suggesting a mechanism for the development of real-time sensing schemes.

Evidence for adaptive evolution of the G6pd gene in the Drosophila melanogaster and Drosophila simulans lineages

Proponents of the neutral theory argue that evolution at the molecular level largely reflects a process of random genetic drift of neutral mutations. Under this theory, levels of interspecific divergence and intraspecific polymorphism are expected to be correlated across classes of nucleotide or amino acid sequences with different degrees of functional constraint, such as synonymous and replacement sites. Nucleotide sites with reduced polymorphism should show comparably reduced levels of interspecific divergence. To examine this hypothesis, we have sequenced 32 and 12 copies of the glucose-6-phosphate dehydrogenase (G6pd) gene in Drosophila melanogaster and Drosophila simulans, respectively. Both species exhibit similar levels of nucleotide polymorphism at synonymous sites. D. melanogaster shows two amino acid polymorphisms, one associated with the cosmopolitan allozyme polymorphism and a second with an allozyme polymorphism endemic to European and North African populations. In contrast, D. simulans shows no replacement polymorphism. While synonymous divergence between species is 10%, which is typical of other genes, there are 21 replacement differences. This level of amino acid sequence divergence, when contrasted with levels of amino acid polymorphism, silent polymorphism, and divergence, is in 10-fold excess over that expected under the neutral model of molecular evolution. We propose that this excess divergence reflects episodes of natural selection on G6pd resulting in fixation of advantageous amino acid mutations in these two recently separated lineages.

Relapsing syphilis

Although penicillin still remains highly effective for syphilis, concerns have been raised that current regimens may be inadequate for the treatment of early syphilis. We report the failure of benzathine penicillin in the treatment of secondary syphilis. Extensive tracing of sexual contact history failed to identify sources of possible reinfection; therefore, we believe that this case represents a treatment failure and an ensuing relapse of secondary syphilis.

Sea urchin maternal mRNA classes with distinct development regulation

Previous studies of newly synthesized proteins during early development in sea urchins have revealed several different patterns of synthesis that can be used to predict the existence of mRNA classes with distinct regulatory controls. We have identified clones for abundant maternal mRNAs that are actively translated during early development by screening a cDNA library prepared from polysomal poly(A)+RNA isolated from 2-cell stage (2-hour) Strongylocentrotus purpuratus embryos. Probes prepared from these cDNA clones and several previously characterized maternal mRNA cDNAs were used to compare relative levels of individual mRNAs in eggs and embryos and their translational status at various developmental stages. These abundant mRNAs can be classified into two major groups which we have termed cleavage stage-specific (CSS) and post cleavage stage (PCS) mRNAs. The relative levels of the CSS mRNAs are highest during the rapid cleavage stage and decrease dramatically at the blastula stage (12-hours). In contrast, PCS mRNAs are present at relatively low levels during the rapid cleavage stage and then increase at the blastula stage. Polysome partition profiles reveal that CSS mRNAs are translated more efficiently than PCS mRNAs in the unfertilized egg, at fertilization, and during the cleavage stages. Following the blastula stage, some CSS transcripts move out of polysomes and accumulate as untranslated RNAs, while newly transcribed PCS mRNAs are recruited into polysomes. These data suggest that the rapid cell cycles following fertilization require high levels of specific cleavage stage proteins, and the synthesis of these proteins occurs preferentially over PCS mRNAs.

A Drosophila phospholipase C gene that is expressed in the central nervous system

A Drosophila phospholipase C (PLC) gene, designated as plc-21, was isolated by screening a genomic DNA library using a cDNA for a previously isolated Drosophila PLC gene, norpA, as probe under reduced stringency hybridization conditions. The gene maps to 21C on the left arm of the second chromosome. Two proteins of 1305 and 1312 amino acids, respectively, were deduced from two classes of cDNA which were isolated. The two putative plc-21 proteins are similar in sequence and overall structure to the beta-class of PLCs found in mammals and differ from each other only by 7 amino acid residues that are present near the C terminus of one of the proteins but not the other. Hybridization of plc-21 cDNA probes to blots of poly(A)+ RNA revealed that the gene encodes a 7.0-kilobase transcript that could be detected in the head but not in the body of adult flies and a 5.6-kilobase transcript that could be detected throughout development and in both heads and bodies of adults. In situ hybridization of cDNA sequences to tissue sections showed that the gene is expressed in the neuronal cell bodies of the optic lobe, central brain, and thoracic ganglia of adults and the brain of larvae. This tissue distribution of plc-21 transcripts is identical to the distribution of transcripts from a Drosophila Go alpha-subunit gene that we reported previously.

Molecular characterization of Drosophila gene encoding G0 alpha subunit homolog

A Drosophila melanogaster gene (dgo) encoding a G protein alpha subunit has been isolated by screening genomic and adult head cDNA libraries using bovine transducin alpha subunit cDNA as probe. The gene, which maps to 47A on the second chromosome, encodes two proteins which are both 354 amino acids long but differ in seven amino acids in the amino-terminal region. The deduced amino acid sequences of the two proteins are 81% identical to that of a rat Go alpha subunit. Analysis of genomic clones revealed that there are eight coding exons and that the putative transcripts for the two proteins differ in the 5'-noncoding regions and the first coding exons but share the remaining six coding exons. The arrangement of two different 5'-noncoding regions on the gene suggests that two different promoters regulate the expression of the transcripts encoding the two proteins. RNA blot analysis detected three transcripts: a 3.9-kilobase (kb) transcript found at all stages of development; a 5.4-kb transcript present predominantly in adult heads; and a 3.4-kb transcript present only in adult bodies. In situ hybridizations of a cDNA probe to adult tissue sections showed that the gene is expressed abundantly in neuronal cell bodies in the brain, optic lobe, and thoracic ganglia.

Mechanism of suppression in Drosophila: regulation of tryptophan oxygenase by the su(s)+ allele

The suppressor gene, su(s)2, in Drosophila melanogaster restores the production of red and brown eye pigments for some purple and vermilion mutant alleles, respectively. We showed previously that the product of the su(s)+ allele caused inhibition of the sepiapterin synthase A produced by the purple mutant but did not affect the wild-type enzyme. Suppression was accomplished by removing su(s)+ from the genome. We now report that the tryptophan oxygenase, produced by suppressible vermilion alleles, is also inhibited by extracts from su(s)+ flies. The inhibition of the vermilion enzyme can be reduced or eliminated, respectively, by prior storage of the extract at 4 or -20 degrees C or by boiling, whereas the wild-type enzyme is not affected by extracts of su(s)+ flies. Also, when the suppressible vermilion strain is raised on certain diets, brown eye pigment production occurs. This epigenetic suppression was reduced by the presence of an extra copy of su(s)+ in the genome. These data support a posttranslational mechanism for regulation of enzyme activity in which the activity of the mutant enzyme is reduced by the product of the su(s)+ allele. How the su(s)+ gene product can distinguish between the normal and the mutant forms of these two enzymes is discussed, along with other mechanisms for suppression that are currently under investigation.

Messenger RNA structure participating in the initiation of synthesis of cucumber mosaic virus coat protein

The sequence of the 5'-terminal 106 nucleotides of cucumber mosaic virus (strain Y) RNA 4, the mRNA coding for viral coat protein, has been determined. The first AUG was located at 77 nucleotides from the 5'-terminus and was confirmed to be an initiation codon by analysis of the N-terminal amino acid sequence of the protein. The nucleotide sequence (positions 77-106) beyond the AUG codon predicted the sequence of ten amino acids corresponding to the N-terminal region of the protein, which exactly matched the determined amino acid sequence containing an acetyl methionine as the N-terminal amino acid. The distance of the initiation codon AUG from the cap structure was 76 nucleotides and the longest among the mRNAs for coat protein of plant viruses so far reported (9-36 nucleotides). This noncoding region is rich in U residues (40%) and the number of G residues (21 nucleotides) is the largest among these mRNAs (usually 1 or 2 residues). A possible secondary structure is postulated for the region, which might be implicated in efficient translation of the RNA 4 in vivo.

Electron microscopy of renal and ocular changes in virus-induced diabetes mellitus in mice

The eyes, kidneys and pancreas of mice (SJL/J) infected with encephalomyocarditis virus were examined by light and electron microscopy. Diabetic mice with the longest duration (6 months) of diabetes showed marked renal and ocular alterations. Fasting blood glucose levels were 17.8-21.9 mmol/l and glycosuria was present. Clinically, based on ophthalmoscopy and fluorescein angiography, retinal vessels were normal. Histologically, moderately decreased numbers of pericytes were noted following trypsin digestion. The basement membrane of inner retinal vessels showed significant thickening in diabetic mice. Corneal epithelial oedema was present and surface microvillus projections were decreased compared with control mice. The kidneys of the same animals showed nodular and diffuse glomerulosclerosis and mesangial thickening. Electron microscopy showed excessive accumulation of basement membrane-like material in the mesangium and the peripheral glomerular region. Histologically, moderate to advanced kidney disease was associated with relatively early retinopathy.

Phase II study of 3-deazauridine in advanced colorectal adenocarcinoma

A phase II study of 3-deazauridine (DAUR) showed poor activity in previously treated patients with advanced colorectal adenocarcinoma. There were no responses among 15 patients treated on a dose schedule of 1200 mg/m2/day for 5 days repeated at 3-week intervals. Toxicity included mild nausea and vomiting, occasional mucositis, diarrhea, and dizziness. A minimal degree of myelosuppression was observed.

Indications for cholecystectomy in ligation of the hepatic artery

Ligation of the hepatic artery has been successfully used in the management of massive bleeding, secondary to hepatic trauma, and in the treatment of metastatic neoplastic disease. The indications for a concomitant cholecystectomy are less well defined. It is generally accepted that cholecystectomy should be performed when ligation is used to control bleeding. In our study, ligation of the hepatic artery was performed, leaving the gallbladder in situ. At autopsy, no pathologic process could be detected in the gallbladder. Microscopic analysis showed fibrosis in the mucosal surface, mild chronic inflammation and nonspecific mononuclear infiltration. We conclude that the changes are insufficient to warrant the removal of a normal gallbladder when ligation of the hepatic artery is performed as treatment for neoplastic disease.

Virus-induced diabetes mellitus: VIII. Passage of encephalomyocarditis virus and severity of diabetes in susceptible and resistant strains of mice

The diabetogenic capacity of the M-variant of encephalomyocarditis (EMC) virus was markedly diminished after passage in mouse kidney cell cultures. One passage in mice fully restored this capacity. Virus harvested after five passages in either susceptible (SWR/J) or resistant (C57BL/6J) strains of mice was capable of producing diabetes in susceptible SWR/J mice but not in resistant C57BL/6J mice. Resistance was not overcome by inoculating mice with high concentrations of virus. Immunofluorescence studies showed that islets from strains of mice (i.e. CBA, AKR, C57BL/6J, A/J) that did not develop diabetes after infection with EMC virus, nonetheless, contained virus antigens. The percentage of cells in the islets containing virus antigens varied from 3-6% in CBA to 13-5% in A/J. In contrast 38% of the islet cells in susceptible SWR/J mice contained virus antigens. It is concluded that both the genetic background of the host and the passage history of the virus influence the development of diabetes.