Agonist-induced vasoactive responses in isolated perfused porcine dental pulpal arterioles

A novel isolated perfused pulpal arteriole preparation and microperfusion system was used to evaluate the direct vasoactive responses of pulpal arterioles to selected agonists. Short lengths of porcine pulpal arterioles (101.7+/-2.2 microm o.d., n=105) were dissected out and placed in an environment-controlled bath on the stage of an inverted microscope. Both ends of the vessel were cannulated and perfused at a controlled rate through the lumen. The diameter of the vessel was measured online. Following equilibration, the vessel was challenged with various agonists: adrenaline (epinephrine), noradrenaline (norepinephrine), phenylephrine, dopamine, isoproterenol, 5-hydroxytryptamine, histamine and adenosine. The endothelium-dependent vasodilator acetylcholine was used to evaluate endothelial cell function. Adrenaline, noradrenaline, phenylephrine, 5-hydroxytryptamine and dopamine caused dose-dependent contractions (adrenaline=noradrenaline>phenylephrine>dopamine>5-hydroxytryptamine). Isoproterenol and histamine provoked a dose-dependent dilation. Adenosine produced pronounced vasodilatation in vessels precontracted with 10(-8)M endothelin-1. Functional adrenergic, histamine, 5-hydroxytryptamine and adenosine receptors are, therefore, present in porcine pulpal arterioles. The isolated perfused pulpal arteriole preparation may prove valuable in understanding local control mechanisms of pulpal microcirculation.

Acetylcholine-induced vasodilation of isolated pulpal arterioles

The presence of cholinergic mechanisms in the control of pulpal microcirculation has been a controversial issue. In this study, we aimed to determine the direct vasoactive responses of isolated pulpal arterioles to acetylcholine, and to investigate whether such responses are endothelium-dependent. Using an in vitro micro-perfusion system, we isolated pig pulpal arterioles, cannulated and perfused them intraluminally, and monitored the diameter. Following equilibration, the vessels were contracted with 10(-5) M noradrenaline, and the effect of increasing doses of acetylcholine was determined. The influence of the muscarinic antagonist, atropine, or the loss of endothelial cell function following saponin treatment was also determined. Acetylcholine induced a dose-dependent vasodilation, reaching 94.6+/-1.4% (n = 22) of the uncontracted diameter at 10(-4) M. The vascular relaxation effect of acetylcholine was abolished in the presence of atropine, and by saponin treatment. Analysis of these data suggests that, in the pig, the acetylcholine-induced vasodilation of incisor pulpal arterioles is endothelium-dependent and mediated by muscarinic receptors.

Implementation of whole body scanner for determining somatotype index at Chang Gung Memorial Hospital

BACKGROUND

Body mass index (BMI) and waist-hip ratio (WHR) using 1-dimensional circumference data have been proven to be highly related to blood pressure and total cholesterol; these 2 indices have been widely used as health indicators in preventive diagnosis and health examination. Sophisticated software, which allows calculation of the triangular mesh related to the body surface in 3D space, is capable of computing the circumference, width, sectional surface, volume, and surface area of the body.

METHODS

Chang Gung Whole Body Scanner (CGWBS) was used to capture 3D whole body surface images. In this study, the human body was divided into 10 segments consisting of the head, breast, wrist, hip, upper arm, forearm, hand, thigh, calf, and foot. Five independent assessments were made on a total of 32 anthropometric sites, including 12 circumferences, 3 widths, 3 profile areas, 7 surface areas, and 7 volumes. In this study, the somatotype index (SI) was computed through anthropometric data after 1,323 subjects were investigated. Correlation analysis was used to describe the relationship between BMI, WHR, SI, and anthropometric data. One-way analysis of variance (ANOVA) and Duncan's multiple range tests were used to examine differences between examination variables across sex and SI groups.

RESULTS

This study found 4 somatotypes from anthropometric data. SI determined by CGWBS has better correlation with anthropometry than WHR or BMI. Of the 644 male subjects, 155 were in the ectomorph group, 232 in the semi-mesomorph group, 136 in the full-mesomorph group, and 121 in the endomorph group. Of the 679 female subjects, 160 were in the ectomorph group, 235 in the semi-mesomorph group, 168 in the full-mesomorph group, and 116 in the endomorph group.

CONCLUSION

The results show that SI has great potential to perform precise somatotype classification.

Role of chicken serum in inhibiting Leucocytozoon caulleryi development in Culicoides arakawae infected by membrane-feeding of infective blood meals

Leucocytozoon caulleryi, the most important pathogen of leucocytozoonsis in several Asian countries, is transmitted by Culicoides arakawae. Although the vector blood meal factors that influence the infectivity of L. caulleryi remain poorly understood, the factors in infected chicken serum remain vital. C. arakawae blood-fed through a membrane were used in this experiment to examine the influence of serum factors on L. caulleryi development. Experimental results indicate that C. arakawae were successfully blood-fed through a chicken-egg-shell membrane and the serum factors in infected chicks significantly affected L. caulleryi sporogony. The inhibition effect of serum factors calculated from sporozoite averages was 53.6% +/- 2.2%. The serum factors, including transmission-blocking antibody, require further detailed study.

Culicoides arakawae (Diptera: Ceratopogonidae) efficiently blood-fed and infected with Leucocytozoon caulleryi through a natural membrane

Culicoides arakawae, the most common Culicoides sp. on chicken farms in East Asia, is an important blood-sucking insect and Leucocytozoon caulleryi vector. How parasites, in an ingested blood bolus, enter the midgut of insects and deal with this complex and biochemically hostile environment is poorly understood. However, successful blood-feeding through a membrane in C. arakawae is beneficial for studying this phenomenon. Therefore, a membrane-feeding method for C. arakawae was developed in. The blood-feeding success rates of C. arakawae fed through five different membranes were: turkey egg at 43.7+/-11.7%, chicken egg at 45.2+/-12.1%, duck egg at 38.8+/-12.0%, pig gut at 0% and chick skin at 0%. In fertility measurements, the average number of eggs produced for C. arakawae fed through egg-shell membrane, at 77.7+/-15.1 per female, was significantly higher (P<0.01) than the 46.7+/-10.6 found in C. arakawae fed on the breast skin of a live chicken. Meanwhile, in parasite infectivity tests, C. arakawae could be infected by L. caulleryi when the vector was blood-fed with infective blood cells reconstituted with specific pathogen-free (SPF) sera through an egg-shell membrane. The sporozoite average and infection rates of inoculated chicks were 166.8+/-12.5 and 100%, respectively. In conclusion, feeding C. arakawae blood through fowl-egg-shell membranes should be an efficient method for in vitro infection of midges as the engorged midges are infected by parasites and display reproductive potential. Furthermore, the method is practical for feeding a large number of midges.

Features of the two gene pairs RD-SKI2W and DOM3Z-RP1 located between complement component genes factor B and C4 at the MHC class III region

Located at the 30 kb genomic region between complement factor B and component C4 are four ubiquitously expressed genes RD, SKI2W, DOM3Z and RP1. Besides RP1, the protein products of the other three genes each has highly conserved homologues or related proteins in lower eukaryotes, contains leucine zipper motifs for protein interaction, and plays important roles related to RNA metabolism. RD is a subunit of the negative transcription elongation factor, critical for the regulation of gene expression. It has an RNA recognition motif and 24 copies of Arg-Asp (RD) repeats. Ski2w is a nucleolar and cytoplasmic protein that has a putative RNA helicase domain. Fusion proteins of human Ski2w expressed in insect cells and bacteria have ATPase activity. The cytoplasmic protein of human Ski2w is associated with the polysomes and probably the 40S subunit of ribosomes. Ski2w is probably involved in the regulation of translation and RNA turnover. Dom3z is a nuclear protein whose yeast homologue forms a complex with an exoribonuclease. RP1 (or STK19) is a Ser/Thr nuclear protein kinase. No homologues of RP1 in lower eukaryotes have been discovered. Six polymorphic residues are present in human Ski2w and two in Dom3z. The potential roles of Ski2w and Dom3z on the clearance of degraded nuclear and cytoplasmic RNA raised their possibilities as susceptibility genes of systemic lupus erythematosus that is a disease with flawed processes in the removal of apoptotic materials.

Genetics of human complement component C4 and evolution the central MHC

The two classes of human complement component C4 proteins C4A and C4B manifest differential chemical reactivities and binding affinities towards target surfaces and complement receptor CR1. There are multiple, polymorphic allotypes of C4A and C4B proteins. A complex multiplication pattern of C4A and C4B genes with variations in gene size, gene dosage and flanking genes exists in the population. This is probably driven by the selection pressure to respond to a great variety of parasites efficiently and effectively, which the bony fish achieved through the multiplication and diversification of the related complement C3 proteins. Complement C4, C3 and C5 belong to the alpha2 macroglobulin protein family but acquired specific features that include an anaphylatoxin domain, a netrin (NTR) domain, and stretches of basic residues for proteolytic processings to form multiple chain structures. Complement C3 and C4 are important in the innate immune response as they opsonize parasites for phagocytosis. The emergence of complement C3 predates proteins involved in the adaptive immune response as C3 is present in deuterostome invertebrates such as echinoderms. The human C4 genes are located in the central MHC at chromosome 6p21.3. C3 and C5 are located at chromosome 19 and 9, respectively, with representatives of the other groups of genes paralogous to the MHC at 19p13.1-p13.3, 1q21-25, and 9q33-34. The central MHC also contains genes for complement components C2 and Bf. These genes appear to have similar evolutionary histories to C3/C4/C5 and are used here to illustrate stepwise processes resulting in co-location of diverse domains, chromosomal duplication, local segmental duplication and divergence of sequence and function. This model of evolution is useful in the investigation of innate and acquired immunity and in seeking explanations for diseases associated with MHC ancestral haplotypes.

Recursive partitioning for tumor classification with gene expression microarray data

Precise classification of tumors is critically important for cancer diagnosis and treatment. It is also a scientifically challenging task. Recently, efforts have been made to use gene expression profiles to improve the precision of classification, with limited success. Using a published data set for purposes of comparison, we introduce a methodology based on classification trees and demonstrate that it is significantly more accurate for discriminating among distinct colon cancer tissues than other statistical approaches used heretofore. In addition, competing classification trees are displayed, which suggest that different genes may coregulate colon cancers.

Differential changes in regional bone mineral density in healthy Chinese: age-related and sex-dependent

To investigate the pattern of age-related and sex-dependent bone mineral density (BMD) changes in the six skeletal regions in healthy Chinese, total-body and regional BMD were measured by dual-energy X-ray absorptiometry (DXA) in 310 women and 387 men aged 20-80 years. In women, a five-phase change was discernible in the axial bones: (1) gradual bone increase from 20-29 years old to maximal BMD at 35-39 years old; (2) maintenance of this level from 35-39 to 40-44; (3) a mild bone decrease from 40-44 to 45-49; (4) a rapid bone decrease from 45-49 to 55-59; and (5) a decelerated bone decrease after 55-59 years old. After validation of menopause status, the decrease of BMD in the late 40s became insignificant in premenopausal women. In appendicular bones, no obvious peak was observed, and significant bone decrease started at 50-54 years old. The overall bone decrease from 35-39 to 70-80 years old was 19.3% for the total body, 16.4% for the head, 29% for the spine, 23% for the pelvis, 18.2% for the ribs, 23.9% for the arms, and 20.4% for the legs. In men, the maximal bone mass was attained at 30-34 and 35-39 years old for axial and appendicular bones, respectively. The age-related bone decrease in the skeletal regions was small, except from 60-64 to 65-69 years old. The overall bone decrease in each region from maximal bone mass to 70-80 years old was 6.7% for the total body, 1.7% for the head, 7.6% for the spine, 11.3% for the pelvis, 9.5% for the ribs, 7.8% for the arms, and 10.4% for the legs. The overall magnitude of reduction in total-body BMD in women was about three times greater than that in men. The pattern of BMD changes differs in each region and is age-related as well as sex-dependent. There appeared to be no significant premenopausal bone decrease.

Genetic, structural and functional diversities of human complement components C4A and C4B and their mouse homologues, Slp and C4

The complement protein C4 is a non-enzymatic component of the C3 and C5 convertases and thus essential for the propagation of the classical complement pathway. The covalent binding of C4 to immunoglobulins and immune complexes (IC) also enhances the solubilization of immune aggregates, and the clearance of IC through complement receptor one (CR1) on erythrocytes. Human C4 is the most polymorphic protein of the complement system. In this review, we summarize the current concepts on the 1-2-3 loci model of C4A and C4B genes in the population, factors affecting the expression levels of C4 transcripts and proteins, and the structural, functional and serological diversities of the C4A and C4B proteins. The diversities and polymorphisms of the mouse homologues Slp and C4 proteins are described and contrasted with their human homologues. The human C4 genes are located in the MHC class III region on chromosome 6. Each human C4 gene consists of 41 exons coding for a 5.4-kb transcript. The long gene is 20.6 kb and the short gene is 14.2 kb. In the Caucasian population 55% of the MHC haplotypes have the 2-locus, C4A-C4B configurations and 45% have an unequal number of C4A and C4B genes. Moreover, three-quarters of C4 genes harbor the 6.4 kb endogenous retrovirus HERV-K(C4) in the intron 9 of the long genes. Duplication of a C4 gene always concurs with its adjacent genes RP, CYP21 and TNX, which together form a genetic unit termed an RCCX module. Monomodular, bimodular and trimodular RCCX structures with 1, 2 and 3 complement C4 genes have frequencies of 17%, 69% and 14%, respectively. Partial deficiencies of C4A and C4B, primarily due to the presence of monomodular haplotypes and homo-expression of C4A proteins from bimodular structures, have a combined frequency of 31.6%. Multiple structural isoforms of each C4A and C4B allotype exist in the circulation because of the imperfect and incomplete proteolytic processing of the precursor protein to form the beta-alpha-gamma structures. Immunofixation experiments of C4A and C4B demonstrate > 41 allotypes in the two classes of proteins. A compilation of polymorphic sites from limited C4 sequences revealed the presence of 24 polymophic residues, mostly clustered C-terminal to the thioester bond within the C4d region of the alpha-chain. The covalent binding affinities of the thioester carbonyl group of C4A and C4B appear to be modulated by four isotypic residues at positions 1101, 1102, 1105 and 1106. Site directed mutagenesis experiments revealed that D1106 is responsible for the effective binding of C4A to form amide bonds with immune aggregates or protein antigens, and H1106 of C4B catalyzes the transacylation of the thioester carbonyl group to form ester bonds with carbohydrate antigens. The expression of C4 is inducible or enhanced by gamma-interferon. The liver is the main organ that synthesizes and secretes C4A and C4B to the circulation but there are many extra-hepatic sites producing moderate quantities of C4 for local defense. The plasma protein levels of C4A and C4B are mainly determined by the corresponding gene dosage. However, C4B proteins encoded by monomodular short genes may have relatively higher concentrations than those from long C4A genes. The 5' regulatory sequence of a C4 gene contains a Spl site, three E-boxes but no TATA box. The sequences beyond--1524 nt may be completely different as the C4 genes at RCCX module I have RPI-specific sequences, while those at Modules II, III and IV have TNXA-specific sequences. The remarkable genetic diversity of human C4A and C4B probably promotes the exchange of genetic information to create and maintain the quantitative and qualitative variations of C4A and C4B proteins in the population, as driven by the selection pressure against a great variety of microbes. An undesirable accompanying byproduct of this phenomenon is the inherent deleterious recombinations among the RCCX constituents leading to autoimmune and genetic disorders.

Technical innovation to calibrate the gantry angle indicators of linear accelerators

Finding the actual zero degree of the gantry angle is important in order to perform the mechanical quality assurance (QA) of linear accelerators. To determine real zero, we must locate a "good surface" which could be defined as a plane on the surface of the gantry head that is perpendicular to the direction of radiation. The actual gantry angle could then be defined as the angle between vertical, as indicated by a plumb bob, and the direction of the beam axis that could be indicated by the position of a BB placed in the central axis and its shadow. From this we located the real zero degree and the good surface. The good surface can be applied to check the important mechanical readouts. The technique we introduce could solve the essential problems of a traditional QA technique, as well as taking up an important role in the quality assurance of a patient's treatment.

Culicoides arakawae (Diptera: Ceratopogonidae) population succession in relation to leucocytozoonosis prevalence on a chicken farm in Taiwan

Leucocytozoonosis caused by Leucocytozoon caulleryi is a significant disease prevalent in open chicken houses of southern and eastern Asia. L. caulleryi is transmitted by Culicoides arakawae, a blood-sucking vector. Leucocytozoonosis prevalence is influenced by vector population succession. Thus this examination was performed on a farm to investigate vector population succession and leucocytozoonosis prevalence in experimental chicks and to obtain the ecology data for assessing the prevalence. The findings were as follows: (1) C. arakawae adults might be highly host specific because they were rarely discovered on cattle or pig farms, and none of the experimental chickens were infected by L. caulleryi on those farms. (2) Identifying and counting gorged and gravid C. arakawae to assess leucocytozoonosis prevalence is a practical strategy. The critical vector index should be 5.0 calculated by dividing the smallest vector mean from the prevalent period by the largest vector mean from the population not causing leucotocytozoonosis. (3) Taking vector means from three or more collections each month, should be the best assessment of leucocytozoonosis prevalence because C. arakawae succession appears to have a 3-week periodicity. Hopefully, these findings will contribute to assessing leucocytozoonosis prevalence.

Molecular genetics of the human MHC complement gene cluster

The human major histocompatibility complex (MHC) complement gene cluster (MCGC) is a highly variable region that is characterized by polymorphisms, variations in gene size and gene number, and associations with diseases. Deficiencies in complement C2 are either due to abolition of C2 protein synthesis by mini-deletions that caused frameshift mutations, or blocked secretion of the C2 protein by single amino acid substitutions. One, two or three C4 genes may be present in a human MCGC haplotype and these genes may code for C4A, C4B, or both. Deficiencies of C4A or C4B proteins are attributed to the expression of identical C4 isotypes or allotypes from the C4 loci, the absence or deletion of a C4 gene, 2-bp insertion at exon 29 or 1-bp deletion at exon 20 that caused frameshift mutations. The C4 genes are either 21 or 14.6 kb in size due to the presence of endogenous retrovirus HERV-K(C4) in the intron 9 of long C4 genes. A deletion or duplication of a C4 gene is always accompanied by its neighboring genes, RP at the 5' region, and CYP21 and TNX at the 3' region. These four genes form a genetic unit termed the RCCX module. In an RCCX bimodular structure, the pseudogene CYP21A, and partially duplicated gene segments TNXA and RP2 are present between the two C4 loci. The RCCX modular variations in gene number and gene size contributed to unequal crossovers and exchanges of polymorphic sequences/mutations, resulting in the homogenization of C4 polymorphisms and acquisitions of deleterious mutations in RP1, C4A, C4B, CYP21B and TNXB genes. RD, SKI2W, DOM3Z and RP1 are the four novel genes found between Bf and C4. RD and Ski2w proteins may be related to RNA splicing, RNA turnover and regulation of translation. The functions of Dom3z and RP1 are being investigated. The complete genomic DNA sequence between C2 and TNX is now available. This should facilitate a complete documentation of polymorphisms, mutations and disease associations for the MCGC.

Organizations and gene duplications of the human and mouse MHC complement gene clusters

The MHC complement gene cluster (MCGC) in most people contains thirteen structural genes, pseudogenes and gene segments. Novel genes RD, SKI2W, DOM3Z and RP1 are organized as two head-to-head gene pairs between complement gene Bf and the first locus of C4. Southern blot analysis shows that single-copy genes for DOM3Z are detectable in primates and other mammals. Sequence analyses revealed that the exon- intron structures of human and mouse DOM3Z genes are identical. Both human and mouse DOM3Z transcripts exhibit splice variants at the 5' regions, although the open reading frames remain identical. Cloning and characterization of the mouse RP1 cDNA revealed a reading frame for 254 amino acids with a bipartite nuclear localization signal close to the amino terminus. The mouse RP1 gene consists of 7 exons and spans 12.9 kb. Located in intron 4 of mouse RP1 is an endogenous retrovirus that probably confers the androgen-responsive expression of the Slp protein in certain male mice. The availability of the complete human and mouse MCGC genomic and cDNA sequences allows further deliberate analyses of gene duplications and evolution. The intergenic region between mouse SLP and C4 genes is more than six times larger than the corresponding region in humans. It contains the functional gene steroid CYP21A, long stretches of repetitive DNA elements, and three partially duplicated gene segments TNXA, SKI2W2 and RP2. The modular duplications of human and mouse RP-C4-CYP21-TNX (RCCX) are sharply different as SKI2W2 is absent in the human MCGC, and TNXA and RP2 are smaller in size but higher in sequence conservation in humans.

Mixed germ cell tumor presenting as intratumoral hemorrhage: report of a case originated from the pineal region

A 17-year-old male patient was brought to our clinic because of sudden onset of headache, vomiting, followed by transient loss of consciousness during a strenuous exercise. Neurologic examinations revealed that the patient had severe sensorimotor and brain stem dysfunction. Examinations of cranial CT and MR imaging showed a huge heterogeneously enhanced tumor originated from the pineal region with tumoral hemorrhage. The tumor markers were found to be high in AFP but not the beta-HCG and CEA. A clinical diagnosis highly suggestive of germ cell tumor was made. Prior to the planned emergency radiation therapy, he received an external ventricular drainage (EVD) and open biopsy of the tumor. Due to a postoperative complication of cerebellar hemorrhage observed 8 hours later, another maneuver was therefore required to extirpate the pineal tumor and cerebellar hematoma. The histological diagnosis proved to be a mixed germ cell tumor with tumoral hemorrhage. Spontaneous intratumoral hemorrhage in germ cell tumor of the pineal region is rare, probably due to compromised venous circulation within the tumor. The bleeding propensity, which may contribute to the formation of cerebellar hematoma, warrants a special attention when a biopsy procedure is to be performed.

An unequal crossover between the RCCX modules of the human MHC leading to the presence of a CYP21B gene and a tenascin TNXB/TNXA-RP2 recombinant between C4A and C4B genes in a patient with juvenile rheumatoid arthritis

The RCCX module of the human MHC class III region is comprised of four genes arranged in tandem: RP, complement C4, steroid 21-hydroxylase (CYP21), and tenascin X (TNX). Variations in the number and genes of the RCCX modules may lead to genetic and/or autoimmune diseases. Restriction fragment length polymorphism (RFLP) analysis was utilized to determine the RCCX modular variation in patients with juvenile rheumatoid arthritis (JRA). In JRA patient L1, RFLP analysis suggested the presence of a bimodular RCCX structure containing both C4A long and C4B short genes, yet missing the markers for the CYP21A and TNXA genes usually located between the C4A and C4B genes. The 7.5-kb genomic fragment spanning the CYP21-TNX-RP2 genes was cloned and sequenced, revealing that a genetic recombination occurred between TNXA of a bimodular RCCX chromosome and TNXB of a monomodular RCCX chromosome. This recombination results in a new MHC haplotype with a CYP21B gene and a TNXB/TNXA-RP2 recombinant between the two C4 genes. Elucidation of the breakpoint region provides further evidence for the instability of the MHC class III gene region as a result of the RCCX modular variation.

[Polymorphic study of CSF1PO locus in Han population in Wuhan]

Using the primers designed by Yoshida, the amplified fragment length polymorphism of the STR locus CSF1PO was studied. 8 alleles were determined from 312 unrelated individuals of Han population living in Wuhan. Sensitivity and suitability of the PCR-STR typing using Yoshida's primers were compared with the one using Hammond's. Results proved that Yoshida's method were more suitable in forensic identification than that of Hammond, especially in the typing of severely degraded DNA samples.

Modular variations of the human major histocompatibility complex class III genes for serine/threonine kinase RP, complement component C4, steroid 21-hydroxylase CYP21, and tenascin TNX (the RCCX module). A mechanism for gene deletions and disease associations

The frequent variations of human complement component C4 gene size and gene numbers, plus the extensive polymorphism of the proteins, render C4 an excellent marker for major histocompatibility complex disease associations. As shown by definitive RFLPs, the tandemly arranged genes RP, C4, CYP21, and TNX are duplicated together as a discrete genetic unit termed the RCCX module. Duplications of the RCCX modules occurred by the addition of genomic fragments containing a long (L) or a short (S) C4 gene, a CYP21A or a CYP21B gene, and the gene fragments TNXA and RP2. Four major RCCX structures with bimodular L-L, bimodular L-S, monomodular L, and monomodular S are present in the Caucasian population. These modules are readily detectable by TaqI RFLPs. The RCCX modular variations appear to be a root cause for the acquisition of deleterious mutations from pseudogenes or gene segments in the RCCX to their corresponding functional genes. In a patient with congenital adrenal hyperplasia, we discovered a TNXB-TNXA recombinant with the deletion of RP2-C4B-CYP21B. Elucidation of the DNA sequence for the recombination breakpoint region and sequence analyses yielded definitive proof for an unequal crossover between TNXA from a bimodular chromosome and TNXB from a monomodular chromosome.

Deficiency of human complement protein C4 due to identical frameshift mutations in the C4A and C4B genes

The complement protein C4, encoded by two genes (C4A and C4B) on chromosome 6p, is the most polymorphic among the MHC III gene products. We investigated the molecular basis of C4 deficiency in a Finnish woman with systemic lupus erythematosus. C4-specific mRNA was present at low concentrations in C4-deficient (C4D) patient fibroblasts, but no pro-C4 protein was detected. This defect in C4 expression was specific in that synthesis of two other complement proteins was normal. Analysis of genomic DNA showed that the proposita had both deleted and nonexpressed C4 genes. Each of her nonexpressed genes, a C4A null gene inherited from the mother, a C4A null gene, and a C4B null gene inherited from the father, all contained an identical 2-bp insertion (TC) after nucleotide 5880 in exon 29, providing the first confirmatory proof of the C4B pseudogene. This mutation has been previously found only in C4A null genes. Although the exon 29/30 junction is spliced accurately, this frameshift mutation generates a premature stop at codon 3 in exon 30. These truncated C4A and C4B gene products were confirmed through RT-PCR and sequence analysis. Among the possible genetic mechanisms that produce identical mutations is both genes, the most likely is a mutation in C4A followed by a gene conversion to generate the mutated C4B allele.

[Study of the high polymorphism STR locus-FGA in Chinese population]

Population genetic study of the complicated STR locus-FGA was performed by the method of PCR in Han population samples. A total of 21 different alleles including 7 interalleles and 63 different genotypes were observed in 349 unrelated individuals. The observed genotype discrimination showed no significant deviation from Hardy-Weinberg equilibrium and 51 family studies showed no mutation. According to the results obtained in this study(DP = 0.9612, PE = 0.7007, PIC = 0.8333), this system can be used as an useful means in forensic identification of both criminal and paternity case.

Regulation by phosphorylation of the zinc finger protein KRC that binds the kappaB motif and V(D)J recombination signal sequences

The DNA binding protein KRC (forkappaB binding andrecognitioncomponent of the V(D)J recombination signal sequence) belongs to a family of large zinc finger proteins that bind to the kappaB motif and contains two widely separated DNA binding structures. In addition to the kappaB motif, KRC fusion proteins bind to the signal sequences of V(D)J recombination to form highly ordered complexes. Here, we report that KRC may be regulated by post-translational modifications. Specific protein kinases present in the nucleus of pre-B cells phosphorylated a KRC fusion protein at tyrosine and serine residues. Such protein modifications increased DNA binding, thereby providing a mechanism by which KRC responds to signal transduction pathways. KRC is a substrate of epidermal growth factor receptor kinase and P34cdc2 kinase in vitro. Our results suggest that activation of the KRC family of transcription factors may provide a mechanism by which oncogenic tyrosine kinases regulate genes with kappaB-controlled gene regulatory elements.

Influence of incubation time, inoculum size, and glucose concentrations on spectrophotometric endpoint determinations for amphotericin B, fluconazole, and itraconazole

We addressed the influence of the incubation time (24 h versus 48 h), starting inoculum size (standard inoculum size, approximately 10(3) CFU/ml, versus large inoculum size, approximately 10(4) CFU/ml), and supplementation with 2% glucose of RPMI 1640 medium on the spectrophotometric determination of the MICs of amphotericin B, fluconazole, and itraconazole. We compared the MICs determined spectrophotometrically with those determined by the standard broth macrodilution method (National Committee for Clinical Laboratory Standards approved guideline M27-A). The agreement between the results of the spectrophotometric and standard methods for amphotericin B testing was 100%; this agreement was independent of the inoculum size and incubation time. On the other hand, the agreement for the results for fluconazole testing and itraconazole testing was dependent on the inoculum size and incubation time. With large inoculum size, excellent agreement can be achieved at 24 h. With standard inoculum size, acceptable agreement can be achieved only at 48 h. In contrast to previous observations, the addition of 2% glucose did not have any significant impact on the growth density at 24 h, nor did it improve the agreement with the standard method. Furthermore, supplemental glucose might falsely elevate the MIC at 48 h.

Four ubiquitously expressed genes, RD (D6S45)-SKI2W (SKIV2L)-DOM3Z-RP1 (D6S60E), are present between complement component genes factor B and C4 in the class III region of the HLA

The association of the HLA class III region with many diseases motivates the investigation of unidentified genes in the 30-kb segment between complement component genes Bf and C4. RD, which codes for a putative RNA binding protein, is 205 bp downstream of Bf. SKI2W (HGMW-approved symbol SKIV2L), a DEVH-box gene probably involved in RNA turnover, is 171 bp downstream of RD (HGMW-approved symbol D6S45). RP1 (HGMW-approved symbol D6S60E) is located 611 bp upstream of C4. The DNA sequence between human RD and RP1 was determined and the exon-intron structure of SKI2W elucidated. SKI2W consists of 28 exons. The putative RNA helicase domain of Ski2w is encoded by 9 exons. Further analysis of the 2.5-kb intergenic sequence between SKI2W and RP1 led to the discovery of DOM3Z. The full-length cDNA sequence of DOM3Z encodes 396 amino acids with a leucine zipper motif. Dom3z-related proteins are present in simple and complex eukaryotes. In Caenorhabditis elegans, Dom3z-related protein could be involved in the development of germ cells. Human RD-SKI2W and DOM3Z-RP1 are arranged as two head-to-head oriented gene pairs with unmethylated CpG sequences at the common 5' regulatory region of each gene pair. The ubiquitous expression pattern suggests that these four genes are probably housekeeping genes.

Effects of early postnatal dexamethasone therapy on calcium homeostasis and bone growth in preterm infants with respiratory distress syndrome

The effects of dexamethasone therapy on calcium homeostasis and bone growth were evaluated in 49 infants (24 placebo and 25 dexamethasone) who participated in a double-blind trial of early dexamethasone therapy for the prevention of chronic lung disease. Dexamethasone (0.25 mg kg(-1) b.i.d. on d 1-7; 0.12 mg kg(-1) b.i.d. on d 8-14; 0.05 mg kg(-1) b.i.d. on d 15-21; 0.02 mg kg(-1) b.i.d. on d 22-28) or saline placebo was given i.v. Serum calcium (Ca), phosphorus (P) and parathyroid hormone (PTH), and the corresponding urinary excretion of calcium (FECa) and phosphorus (FEP) were measured on d 2, 3, 7, 10, 14, 21 and 28 after starting the study. Radiographic evaluations of bone growth were also evaluated. Infants in the dexamethasone group had significantly higher PTH on d 2 (p < 0.01), 7 and 14 (p < 0.05) than infants in the placebo group. The dexamethasone-treated infants also had significantly higher FEP on d 2, 7 and 14 (p < 0.05) and lower FECa on d 7 and 14 (p < 0.05) than control infants. There was no significant difference between the groups in bone growth during the study. It was concluded that early dexamethasone therapy causes a transient elevation in PTH without apparent change in bone growth. The long-term effect remains to be evaluated further.

Technetium-99m-HMPAO brain SPECT in neonates with hypoglycemic encephalopathy

Regional brain injury in three neonates with hypoglycemic encephalopathy are presented using serial 99mTc-hexamethyl propyleneamine oxime (HMPAO) SPECT and, for comparison, MRI. During the acute stage, both 99mTc-HMPAO SPECT and MRI reveal abnormalities in the posterior cerebrum. Technetium-99m-HMPAO SPECT reveals further areas of insult, for example the frontal lobes. The degree of hypoperfusion correlates with the clinical severity of hypoglycemia during the neonatal period and subsequent neurological sequelae. Follow-up with HMPAO SPECT several months after insult demonstrates persistent hypoperfusion in some areas, mainly in the occipital and posterior parietal regions. MRI can depict morphological changes with superior resolution. Because morphological change generally follows slowly after functional change, MRI is less sensitive than HMPAO SPECT in detecting and predicting the extent of hypoglycemic cerebral injury during the acute phase. HMPAO SPECT during the acute stage is a valuable tool for evaluating the extent and severity of brain injury in neonates with hypoglycemic encephalopathy.

Holoprosencephaly due to mutations in ZIC2, a homologue of Drosophila odd-paired

Holoprosencephaly (HPE) is the most common structural anomaly of the human brain and is one of the anomalies seen in patients with deletions and duplications of chromosome 13. On the basis of molecular analysis of a series of patients with hemizygous deletions of the long arm of chromosome 13, we have defined a discrete region in band 13q32 where deletion leads to major developmental anomalies (the 13q32 deletion syndrome). This approximately 1-Mb region lies between markers D135136 and D13S147. Patients in which this region is deleted usually have major congenital malformations, including brain anomalies such as HPE or exencephaly, and digital anomalies such as absent thumbs. We now report that human ZIC2 maps to this critical deletion region and that heterozygous mutations in ZIC2 are associated with HPE. Haploinsufficiency for ZIC2 is likely to cause the brain malformations seen in 13q deletion patients.

The human DEVH-box protein Ski2w from the HLA is localized in nucleoli and ribosomes

The human helicase gene SKI2W is located between RD and RP1 in the class III region of the major histocompatibility complex. Transcripts of SKI2W are detectable in RNA samples isolated from multiple tissues. The protein product Ski2w shares striking amino acid sequence similarities to the yeast antiviral protein Ski2p that controls the translation of mRNAs, probably based on the mRNA structural integrity. Whether this translational regulation mechanism for cellular and viral RNAs exists in mammals is under investigation. Antisera against human Ski2w were generated using fusion proteins produced in bacteria or insect cells. Western blot analysis showed that the endogenous Ski2w protein is approximately 140 kDa in size and is enriched in polysomal fractions of cytoplasmic extracts from HeLa cells. Ribosomal profile studies revealed that Ski2w distributed throughout the entire sucrose gradient in the presence of Mg2+, but co-sedimented with the 18S rRNA-containing 40S subunit and the small ribosomal subunit protein S27a in the presence of EDTA. The co-sedimentation of Ski2w with the 40S subunit is not affected by RNase A treatment of the cell extract, or the addition of KCl to 0.5 M, suggesting that Ski2w is associated with the 40S ribosomal subunit. Indirect immunofluorescence experiments showed that human Ski2w is localized in the nucleoli and in the cytoplasm. In essence, human Ski2w is present at the sites of ribosome biogenesis and protein synthesis.

Voriconazole against fluconazole-susceptible and resistant candida isolates: in-vitro efficacy compared with that of itraconazole and ketoconazole

We compared the in-vitro activity of fluconazole, itraconazole, ketoconazole and voriconazole against 67 blood isolates of Candida spp. exhibiting a wide range of fluconazole MICs (0.125 to >64 mg/L). Voriconazole was the most potent in vitro, followed by itraconazole, ketoconazole and fluconazole. Itraconazole and voriconazole had in-vitro activity against fluconazole-susceptible and -resistant candida isolates. Higher itraconazole and voriconazole MICs were observed in isolates exhibiting higher fluconazole MICs, suggesting cross-resistance. Itraconazole and voriconazole MICs of > or =16 mg/L were observed only in Candida albicans and Candida tropicalis. Candida krusei and Candida glabrata exhibited itraconazole MICs of 0.5-1 mg/L and voriconazole MICs of 0.25-0.5 mg/L.

In vitro comparative efficacy of voriconazole and itraconazole against fluconazole-susceptible and -resistant Cryptococcus neoformans isolates

In vitro susceptibility testing for 50 clinical isolates of fluconazole-susceptible or -resistant Cryptococcus neoformans was performed with itraconazole and voriconazole. Voriconazole was more potent than itraconazole for fluconazole-susceptible isolates and as potent as itraconazole for fluconazole-susceptible dose-dependent isolates and for fluconazole-resistant isolates. For fluconazole-resistant isolates, the voriconazole and itraconazole MICs ranged from 1 to 2 microg/ml.

Comparison of PCR and culture to the indirect fluorescent-antibody test for diagnosis of Potomac horse fever

Potomac horse fever is an acute systemic equine disease caused by Ehrlichia risticii. Currently, serologic methods are widely used to diagnose this disease. However, serologic methods cannot determine whether the horse is presently infected or has been exposed to ehrlichial antigens in the past. The purpose of the present study was to compare the sensitivities of the nested PCR and cell culture with that of the indirect fluorescent-antibody (IFA) test for the diagnosis of Potomac horse fever. Blood and fecal specimens serially collected from a pony experimentally infected with E. risticii Maryland, blood specimens serially collected from mice inoculated with E. risticii Ohio 380, and blood and/or fecal specimens collected from 27 horses which had clinical signs compatible with Potomac horse fever were examined. These horses resided in Kentucky, Indiana, Pennsylvania, and Vermont. The IFA test titer became positive after 6 days postinoculation (p.i.) for the pony. A culture of the blood of the pony was positive for E. risticii starting on day 1 and was positive through day 28 p.i. By the nested PCR, E. risticii was detectable in the blood and feces of the pony starting on day 1 and was detectable through day 32 p.i. E. risticii was detected in the blood of subclinically infected mice by the nested PCR. Twenty-two clinical specimens were seropositive for E. risticii by the IFA test, with titers ranging from 1:20 to 1:1,280. E. risticii was cultured from 95% (20 of 21) of seropositive clinical blood specimens. E. risticii was detected in the blood by PCR in 81% (17 of 20) of the culture-positive clinical specimens. The study indicated that the nested PCR is as sensitive as culture for detecting infection with E. risticii.

Combination therapy with fluconazole and flucytosine in the murine model of cryptococcal meningitis

This study elucidates the role of combined fluconazole and flucytosine as therapy for cryptococcosis in the murine model of meningitis. Three strains of Cryptococcus neoformans for which the range of fluconazole MICs was wide--2 microg/ml (susceptible strain), 8 microg/ml (moderately susceptible strain), and 32 microg/ml (resistant strain)--were used for infection. One day postinfection, the mice were randomized into eight treatment groups: placebo; flucytosine (40 mg/kg of body weight/day); fluconazole at 3 mg/kg/day (low dosage), 10 mg/kg/day (moderate dosage), or 20 mg/kg/day (high dosage); and combined flucytosine and fluconazole at low, moderate, or high doses of fluconazole. Three major findings were demonstrated: (i) correlation between the MICs for the isolates and the in vivo effectiveness of fluconazole as assessed by the reduction in cryptococcal brain burden, (ii) a dose-response curve (a higher dose of fluconazole was significantly more efficacious than a lower dose [P < 0.001]), and (iii) synergism between fluconazole and flucytosine (therapy with a combination of fluconazole and flucytosine was superior to therapy with either agent alone [P < 0.01]).

Characterization of focal hepatic masses by dynamic contrast-enhanced MR imaging: findings in 311 lesions

This study aimed to determine the overall accuracy of known enhancement patterns for the characterization of a large series of focal hepatic masses on dynamic contrast-enhanced magnetic resonance (MR) images. Breath-hold T1-weighted images of the liver acquired before intravenous gadolinium administration and serially over 6-10 min after contrast injection were acquired in < 25 a using FLASH or rapid spin-echo pulse sequences. A total of 311 proven focal hepatic masses in 128 patients were analyzed, including 192 malignant lesions (166 metastases and 26 hepatomas) and 119 benign lesions (48 cavernous hemangiomas, 45 hepatic cysts, and 26 other abnormalities). The lesions were evaluated for a variety of characteristics independently by two reviewers who were blinded to results. Cavernous hemangiomas showed early peripheral nodular enhancement (80% sensitivity and 99% specificity) and hepatic cysts showed no enhancement (100% sensitivity and 95% specificity). Hepatic metastases showed variable, moderate enhancement (47% by one reviewer and 74% by the other). Metastatic lesions from hypervascular primary neoplasms displayed peak enhancement during the hepatic artery dominant (bolus) phase, while other malignant neoplasms showed later peak enhancement (72% sensitivity and 77% specificity). Five metastatic foci with early homogeneous enhancement showed a delayed peripheral washout of contrast (rim sign), while no nonmetastatic foci displayed this finding (3% sensitivity and 100% specificity). Characteristic enhancement patterns of focal hepatic lesions were described in a large series of patients. This study confirms results of previous investigators who have shown that early nodular peripheral enhancement was highly specific for hemangiomas and lack of enhancement was highly specific for hepatic cysts. Hypervascular metastatic foci show earlier peak enhancement than other malignant lesions. Some (2-3%) metastatic lesions display a peripheral washout of contrast on serial images, with 100% specificity.

Pulmonary cavernous hemangiomatosis treated with interferon alfa-2a

Pulmonary hemangiomatosis is a rare, usually fatal disorder characterized by diffuse proliferation of blood vessels within the thorax. We describe a 7-year-old boy with cavernous-type pulmonary hemangiomatosis successfully treated with interferon alfa-2a. He presented with respiratory distress and hemoptysis that were alleviated during a 2-year follow-up period.

The mouse DNA binding protein Rc for the kappa B motif of transcription and for the V(D)J recombination signal sequences contains composite DNA-protein interaction domains and belongs to a new family of large transcriptional proteins

Rc is a DNA binding protein with dual specificities for the V(D)J recombination signal sequences and for the B motif of the immunoglobulin kappa chain gene enhancer. The largest Rc transcript present in lymphoid cells/tissues is approximately 9 kb. Molecular cloning and sequence determination for 8822 bp of mouse Rc cDNA revealed an open reading frame of 2282 amino acids and long 5'- and 3'-untranslated regions. The derived amino acid sequence contains multiple DNA and protein interaction domains. Composite ZAS structures with tandem zinc fingers, an acidic motif, and a Ser/Thr-rich segment are located near the N-terminal and the C-terminal regions. The middle region of Rc contains a lone zinc finger, an acidic motif, a Ser-rich region, a nucleus localization signal, and GTPase motifs. Cloning and characterization of a mouse Rc gene show that the Rc cDNA corresponds to seven exons located in a genomic region spanning 70 kb. Exon 2 is exceptionally large, with 5487 bp. cDNA cloning and Northern blot analyses revealed multiple Rc transcripts, probably generated by alternative splicings. Sequence comparisons show that Rc belongs to a ZAS protein family that is involved in gene transcription and/or DNA recombination. The major histocompatibility complex class I gene enhancer binding proteins MBP1 and MBP2 are other representatives of this ZAS protein family.

Isolated congenital left ventricular diverticulum

Congenital diverticulum of the left ventricle, a rare malformation, is usually associated with midline thoracoabdominal defect. We describe a case with congenital left ventricular diverticulum presenting as an isolated lesion. The lesion was suspected on two-dimensional echocardiography and was confirmed by cardiac catheterization and magnetic resonance imaging.

Self-expandable metallic stents in the management of malignant biliary obstruction

To overcome problems with conventional plastic endoprostheses, a study was conducted to determine the clinical efficacy of self-expandable metallic stents in the palliative treatment of malignant biliary obstruction. From May 1994 to March 1995, 19 self-expandable metallic stents were implanted in 13 consecutive patients with malignant obstructive jaundice due to cholangiocarcinoma (four patients), ampullary carcinoma (six), pancreatic carcinoma (one), and hepatic hilar lymph node metastasis (two). All patients underwent percutaneous transhepatic biliary drainage followed by stent insertion, except for two patients where the T-tube tract was used as access and another with previous placement of a polyethylene internal-external drainage catheter for more than 6 months. When both lobes of the biliary system were to be drained, stents were placed either side by side through punctured, separate hepatic ducts or, using a T configuration, through a single transhepatic tract. Percutaneous transhepatic stent placement was technically successful in all patients. After a mean follow-up of 5.9 months (range, 1-10 mo), 10 of 13 patients were still alive while three had died of nonprocedure-related causes. In 10 patients, total serum bilirubin levels decreased significantly (from 136.8 +/- 157 mumol/L to 34.2 +/- 22.2 mumol/L), while it increased in three patients. Two patients had stent occlusions at 2 and 3 months after stent placement, which required intervention. The overall patency period ranged from 1 to 9 months (mean, 5.1 mo). Our results confirm that the use of metallic stents is effective in the palliative treatment of malignant jaundice.

G alpha 13 stimulates Na+-H+ exchange through distinct Cdc42-dependent and RhoA-dependent pathways

Activity of the ubiquitously expressed Na+-H+ exchanger subtype NHE1 is stimulated upon activation of receptor tyrosine kinases and G protein-coupled receptors. The intracellular signaling pathways mediating receptor regulation of the exchanger, however, are poorly understood. Using transient expression of dominant interfering and constitutively active alleles in CCL39 fibroblasts, we determined that the GTPases Ha-Ras and Galpha 13 stimulate NHE1 through distinct signaling cascades. Exchange activity stimulated by constitutively active RasV12 occurs through a Rafl- and mitogen-activated protein kinase kinase/extracellular signal-regulated kinase kinase (MEK)-dependent mechanism. Constitutively active Galpha 13QL, recently shown to stimulate the Jun kinase cascade, activates NHE1 through a Cdc42- and MEK kinase (MEKK1)-dependent mechanism that is independent of Rac1. Constitutively active Rac1V12 does stimulate NHE1 through a MEKK1-dependent mechanism, but dominant interfering Rac1N17 does not inhibit Galpha 13QL-mediated or constitutively active Cdc42V12-mediated stimulation of the exchanger. Conversely, Cdc42NI7 does not inhibit Rac1V12 activation of NHE1, suggesting that Rae I and Cdc42 independently regulate a MEKK1-dependent activation of the exchanger. Rapid (<10 min) stimulation of NHE1 with a Ga13/Gaz chimera also was inhibited by a kinase-inactive MEKK. Galpha 13QL, but not RasV12, also stimulates NHE1 through a RhoA-dependent pathway that is independent of MEKK, and microinjection of mutationally active Galpha 13 results in a Rho phenotype of increased stress fiber formation. These findings indicate a new target for Rho-like proteins: the regulation of H+ ex- change and intracellular pH. Our findings also suggest that a MEKK cascade diverges to regulate effectors other than transcription factors.

Magnetic resonance spectroscopic findings in patients with subcortical ischemic stroke

BACKGROUND

Biochemical changes inside the brain during acute ictus have been extensively studied by means of magnetic resonance spectroscopy (MRS). Previous reports revealed that cerebral cortical infarction causes reduction of N-acetylaspartate (NAA) and elevation of lactate. This study was designed to evaluate the biochemical changes in subcortical infarction.

METHODS

Nine normal controls and four patients, including two thalamic infarct, one basal ganglia infarct, and one putamen infarct cases were examined using MRS in addition to magnetic resonance imaging (MRI). Evaluation experiments were performed on a Siemens Wagnetom 63SP machine. A spin echo sequence with TE 270 msec was applied for the measurement. The voxel was located at basal ganglia in the controls and at the lesion site, as well as at the contralateral corresponding region in the patients.

RESULTS

Three resonance signals were present in the spectrum-NAA, choline-containing compounds (Cho) and creatine-phosphocreatine (Cr). The NAA/Cho and NAA/Cr ratios were reduced significantly on the lesion side compared with the controls. NAA/Cho also decreased on the lesion side compared with the healthy side.

CONCLUSIONS

There is a remarkable reduction of NAA concentration even in subcortical infarction. Further study is needed for the detection of changes in lactate in patients with subcortical lesion.

Fat in the prediction of bone strength of porcine lumbar vertebrate by quantitative computed tomography

The influence of fat content on quantitative computed tomography (QCT) values was studied using porcine lumbar vertebrae as a model. A total of 72 cancellous bone columns, prepared from 18 vertebrae, underwent QCT examination before and after defatting. Mechanical testing and ashing were performed to obtain the ultimate strength and bone mineral content. The ultimate strength was calculated as a power function of apparent density using linear regression on a log-log plot and the power coefficient was 1.88. QCT values were positively correlated with bone density. QCT values of defatted specimens correlated much better with ultimate strength than those of fresh specimens. The average fat content was 27.2%. The QCT values decreased linearly with increasing fat content with a slope of 7.9 mg/cm3/% fat and a correlation coefficient of 0.65. The results provided basic data for the calibration of the machine and the principles for the interpretation of QCT values excluding the fat influence.

Renal tubular acidosis complicated with hypokalemic periodic paralysis

Three Chinese girls with hypokalemic periodic paralysis secondary to different types of renal tubular acidosis are presented. One girl has primary distal renal tubular acidosis complicated with nephrocalcinosis. Another has primary Sjögren syndrome with distal renal tubular acidosis, which occurs rarely with hypokalemic periodic paralysis in children. The third has an isolated proximal renal tubular acidosis complicated with multiple organ abnormalities, unilateral carotid artery stenosis, respiratory failure, and consciousness disturbance. The diagnostic evaluation and emergent and prophylactic treatment for these three types of renal tubular acidosis are discussed.

Ultrasonographic evaluation of multicystic dysplastic kidney

Eleven cases of multicystic dysplastic kidney (MCDK) in children were diagnosed over an 11 year period. All underwent postnatal ultrasound (US) studies. Four different patterns of MCDK were recognized: (1) Six cases presented with the classic sonogram of multicystic components. (2) Three cases had hydronephrotic form; correct diagnosis between hydronephrotic form of MCDK and hydronephrosis was difficult as there was a medially-located, large, lobulated cyst and there was connection between the large cyst and neighboring small cysts. (3) One case initially presented with normal renal sonogram but a small cyst appeared on follow up sonogram and there was also decreased renal size and increased echogenecity. (4) One case had only two moderate-sized cysts but no identifiable renal parenchyma. Two cases had follow-up US examination and one dysplastic kidney decreased in renal size on follow-up sonogram. Intravenous urography and radionuclide study revealed both these dysplastic kidneys to be nonfunctioning. Nine children had surgical resection of the diseased kidneys. Contralateral renal anomalies were detected in five children, which included ureteropelvic junction stenosis, ureterovesical junction stenosis, distal ureteral stenosis and polycystic kidney disease. Two of three hydronephrotic forms of MCDK had contralateral ureteral stenosis. Two of six classic forms of MCDK had contralateral ureteral stenosis. The proportion of contralateral ureteral stenosis was higher in the group of hydronephrotic forms of MCDK. Ultrasonography is beneficial for conclusive diagnosis of MCDK; however, a differential diagnosis of simple hydronephrosis needs to be considered.

Human helicase gene SKI2W in the HLA class III region exhibits striking structural similarities to the yeast antiviral gene SKI2 and to the human gene KIAA0052: emergence of a new gene family

Helicases are essential enzymes for life because DNA replication, DNA repair, recombination, transcription, RNA splicing and translation all involve more than one helicase to unwind DNA or RNA. We have discovered, cloned and partially characterized a novel human helicase gene, SKI2W. The human SKI2W is located between the RD and RP1 genes in the class III region of the major histocompatibility complex (MHC) on chromosome 6, a genomic region associated with many malignant, genetic and autoimmune diseases. Derived amino acid sequence of human SKI2W showed an open reading frame for 1246 residues. It contains consensus sequences for structural motifs of an RNA helicase with a DEVH box. It has a leucine zipper motif that may be important for protein dimerization, and an RGD motif close to the N-terminus that might serve as a ligand for integrin or cell adhesion molecules. SKI2W shares a striking and extensive similarity to the yeast Ski2p that is involved in the inhibition of translation of poly(A) negative [poly(A)-] RNA, and plays an important role in antiviral activities. Human SKI2W fusion protein expressed in insect cells using a baculovirus vector has ATPase activity. The human SKI2W protein and the yeast Ski2p share extensive sequence similarities to another putative human protein KIAA0052, suggesting the presence of a new gene family that may be involved in translational regulation of cellular and viral RNA.

Complement component C4 gene intron 9 as a phylogenetic marker for primates: long terminal repeats of the endogenous retrovirus ERV-K(C4) are a molecular clock of evolution

The complement component C4 genes of Old World primates exhibit a long/short dichotomous size variation, except that chimpanzee and gorilla only contain short C4 genes. In human it has been shown that the long C4 gene is attributed to the integration of an endogenous retrovirus, HERV-K(C4), into intron 9. This 6.36 kilobase retroviral element is absent in short C4 genes. Here it is shown that the homologous endogenous retrovirus, ERV-K(C4), is present precisely at the same position in the long C4 gene of orangutan and African green monkey. Determination of the short C4 gene intron 9 sequences from human, three apes, two Old World monkeys, and a New World monkey allowed the establishment of consistent phylogenetic trees for primates, which favors a chimpanzee-gorilla clade. The 5' long terminal repeats (LTR) and 3' LTR of ERV-K(C4) in long C4 genes of human, orangutan, and African green monkey have similar sequence divergence values of 9.1%-10.5%. These values are more than five-fold higher than the sequence divergence of the homologous intron 9 sequences between the long and short C4 genes in higher primates. The latter is probably a result of homogenization or concerted evolution. We suggest that the 5' LTR and 3' LTR of an endogenous retrovirus can serve as a reliable reference point or a molecular clock for studies of gene duplication and gene evolution. This is because the 5'/3' LTR sequences were identical at the time of retroviral integration and evolved independently of each other afterwards. Our data provides strong evidence for the short C4 gene being the ancestral form in primates, trans-species evolution, and the "slow-down" phenomenon of the sequence divergence in great apes.

Diagnosis of disseminated candidiasis by fine needle aspiration of lymph node and by splenic imprint in a patient with acute promyelocytic leukemia

Cytologic studies were done on fine needle aspirates of the lymph node and imprints of splenic biopsies from a patient with acute promyelocytic leukemia who was febrile while being treated with chemotherapy. Examination of the lymph node aspirates revealed pus and numerous pseudohyphae which were later identified as Candida tropicalis. When multiple nodular lesions were detected in the spleen by abdominal sonography and CT scan, needle biopsy of the spleen was done. Cytologic examination of touch imprints of the biopsy disclosed intracellular fungal blastospores. The patient was treated with and responded well to amphotericin B and 5-fluorocytosine. As a result of our experience with this patient we emphasize the importance of close incorporation of clinical information and diagnostic cytology. With such a cooperation, cytologic studies become a most useful method for diagnosis.

Successful resection of a minute icteric hepatocellular carcinoma--case report

A 38-year-old male was admitted to our department with jaundice. Imaging studies including ultrasonography, ERCP, PTC and computed tomography (CT) revealed a hilar lesion. Right hepatic lobectomy, caudate lobectomy, excision of CBD and restoration of biloenteric continuity was performed. Pathological examination showed an icteric hepatoma (1.2 x 0.8 x 0.8 cm in size) originating in the caudate lobe. The tumor thrombus occupied the common hepatic duct and the right intrahepatic duct. The postoperative course was fairly unremarkable, and the patient has remained in good health for four years after surgery without any sign of recurrence.