Benign isolated abducens nerve palsy in Mycoplasma pneumoniae infection

Benign acquired isolated abducens nerve palsy in children is a rare condition. The palsy may be due to a postinfectious process; Epstein-Barr virus and cytomegalovirus have been documented etiologies. This is a case report of a boy 26 months of age with benign acquired isolated bilateral abducens nerve palsy. It may be the first report of Mycoplasma pneumoniae as the cause of benign isolated abducens nerve palsy in children.

Polyethylene failure in New Jersey low-contact stress total knee arthroplasty

From January 1985 to December 1990, 598 consecutive New Jersey low-contact stress (LCS) total knee arthroplasties (TKAs) were performed for gonarthrosis. Among these 598 operations, 322 were with rotating platform elements and 276 were with meniscal bearing elements. During 5 to 8 years of follow-up, eight knees had severe symptomatic polyethylene failure that required revision surgery; all eight cases were meniscal bearing types. The failed polyethylene inserts were retrieved and studied. It was observed that there were four probable failure mechanisms associated with the catastrophic polyethylene wear. First, insufficient thickness of the meniscal bearing was the major reason for wear. Second, the malpositioning of the metal tibial tray in the transverse plane resulted in the breaking of the meniscal bearing. Third, the inability of the patellar to rotate due to tissue ingrowth made the polyethylene break. Last, yellowing of the subsurface of the meniscal bearing was a sign of polyethylene failure. These four possible failure mechanisms are all associated with the design of the meniscal bearing type of LCS knee prostheses. Therefore, it is suggested that the design of the LCS knee prosthesis should be modified.

Time-frequency spectral analysis of heart rate variability during induction of general anaesthesia

We have examined the spectral components of heart rate variability (HRV) during induction of anaesthesia with thiopentone, tracheal intubation and subsequent inhalation of isoflurane-nitrous oxide. Commonly used spectral analysis methods such as fast Fourier transformation or autoregressive modelling require stationary data and are not suitable for the rapidly changing HRV data in this period. An advanced spectral analysis method, time-frequency analysis, which can treat non-stationary data, was used in this study. Multiple spectra were generated to demonstrate the time-related spectral components of HRV. Mid-frequency power (MF, 0.08-0.15 Hz), high-frequency power (HF, 0.15-0.5 Hz) and MF/HF ratio at baseline, after induction (before intubation), immediately after intubation and during maintenance periods were calculated and compared. MF and HF powers decreased after induction and were reduced further in the maintenance period but MF/HF ratio remained unchanged after induction. Immediately after intubation MF and HF powers did not differ significantly from the immediate pre-intubation values, but MF/HF ratio did.

The correlation between ultrasound-detected renal parenchymal thickness and isotope-detected individual renal function

Ultrasound has been used as a convenient examination method to obtain an estimate of the kidney size and parenchymal thickness. The aim of this study was to determine the relationship between the renal parenchymal thickness and individual renal function. Renal ultrasonography to determine parenchymal thickness and 99mTc-DTPA renal scan to detect individual renal function were carried out on 30 patients. The statistic analysis showed poor correlation between these two factors. The correlation coefficients is 0.1 only. However, the correlation coefficients of the difference of bilateral renal parenchymal thickness and the difference of bilateral renal function in the same patient is much higher (r = 0.67). So, it is unreliable to predict the random single renal function based on parenchymal thickness only. However, in the same patient, it is sometimes worthwhile to differentiate bilateral renal function based on the difference of renal parenchymal thickness between the two kidneys.

Predicting the outcome of hemodialysis arteriovenous fistulae using duplex ultrasonography

Duplex ultrasonography is a reliable method for assessing the anatomic features and blood flow rate of a vascular access point of hemodialysis. We assessed the value of measurement of cross-sectional area and blood flow rate of the major outflow veins using duplex ultrasonography in predicting the outcome of fistulae. Radiocephalic arteriovenous fistulae were created in 126 consecutive end-stage renal failure patients (55 men, 71 women; aged 20-83 yr) and examined using duplex ultrasonography in the second week following surgery. Examinations were repeated in 45 of the 126 fistulae in the third week. The outcome of new fistulae was classified as success or failure. The failure group fistulae were further classified as delayed maturation or primary failure. The cross-sectional area (12.1 +/- 3.5 vs 6.9 +/- 2.4 mm2) and blood flow rate (825.6 +/- 424.3 vs 303.7 +/- 114.5 mL/min) were significantly lower in the failure group, but there was no difference between the subgroups of primary failure and delayed maturation. Receiver-operating characteristic plots were generated for cross-sectional area and blood flow rate. The best cut-off point for distinguishing successful outcome from failure was 8.5 mm2 for cross-sectional area (sensitivity 0.823, specificity 0.867, positive predictive value 0.952, negative predictive value 0.605) and 425 mL/min for blood flow rate (sensitivity 0.813, specificity 0.933, positive predictive value 0.975, negative predictive value 0.609). Our findings show the cross-sectional area and blood flow rate, as measured using duplex ultrasonography, are useful in predicting the outcome of vascular access points of hemodialysis.

Early genetic and cellular responses in the smooth muscle layer of obstructed ureters in a rat model of obstructive uropathy

OBJECTIVE

To investigate the early genetic and cellular responses in the smooth muscle layer of completely obstructed ureters, and to determine whether myocytes proliferate (hyperplasia) in the ureters during the early stage of obstructive uropathy.

MATERIALS AND METHODS

The study comprised 35 female Sprague-Dawley rats which had undergone unilateral ligation of their ureters. After ureteric ligation, five rats each were killed and examined at 0.5, 1, 2, 4, 8, 16 and 24 h after ligation. The proximal portion of the ureters was prepared for light and electron microscopy. The expression of c-Fos, c-Jun, c-Myc and Ki-67 antigen was assessed immunohistochemically.

RESULTS

c-Fos and c-Jun were detected 2 h after ligation and the expression of these two proteins reached a maximum after 4 h, becoming undetectable 16 h after ligation. The expressions of c-Fos and c-Jun were strongly correlated (r = 0.9854, P < 0.001). The expressions were of c-Myc and Ki-67 antigen was not detected within 24 h after ureteric ligation. The amount of rough endoplasmic reticulum (rER) in the ligated ureters increased soon after complete ligation and the increase continued throughout the period of ureteric obstruction (r = 0.9699, P < 0.001). The change in rER was also significantly correlated with the expression of c-Fos and c-Jun within 8 h after ligation.

CONCLUSION

The expression of c-Fos and c-Jun, but not c-Myc, might contribute to the hypertrophy of the ureteric smooth muscle layer during the course of complete ureteric obstruction. There is no hyperplasia in ureteric smooth muscle in the early stages of obstructive uropathy.

Molecular genetics of glycophorin MNS variants

The antigens for the MNS blood group system are Glycophorins A and B (GPA,GPB), products of the GPA gene family. The existence of close to 40 variant phenotypes of this blood group system has been documented by serological analyses. Here is summarized the molecular basis for a large number of variants, including all the variants of the Miltenberger complex and several isoforms of Sta; also, Dantu, Sat, He, Mg, and deletion variants Ena, S-s-U- and Mk. The diversity is based predominantly on gene recombinations, namely unequal homologous recombinations and/or gene conversions, often coupled to pre-mRNA splicing. Most rearrangements occurred between GPA and GPB alleles, and were confined to hot-spots within the 4 kb region coding for the extracellular domain. The homologous region in GPE, the third member of the gene family, was involved only rarely. Sites of the variant epitopes are mapped to new intra- and inter-exon junctions or to patches of previously silenced sequences that become expressed following recombination.

Human D(IIIa) erythrocytes: RhD protein is associated with multiple dispersed amino acid variations

As a partial D antigen of the Rh blood group system, the D category IIIa phenotype occurs mainly in Blacks, but its molecular basis has not been defined. Here we describe studies of the D category D(IIIa) and VS+ red blood cells (RBC) from two unrelated probands by Southern blot, cDNA PCR, and nucleotide sequencing. Rh haplotyping by Sph I restriction fragment length polymorphisms indicated that the two probands carried Dce/dCe and Dce/DcE genotypes, respectively. Sequence analysis of Rh cDNAs showed that their erythroid cells expressed both D and CE transcripts. Nevertheless, the D transcripts were found to contain four nucleotide changes scattered in three exons: nt455 A-to-C (exon 3), nt602 C-to-G (exon 4), nt 654 C-to-G (exon 5), and nt667 T-to-G (exon 5). These variations resulted in the following amino acid substitutions characteristic of RhCE polypeptides: 152 Asn-to-Thr, 201 Thr-to-Arg, 218 Ile-to-Met, and 223 Phe-to-Val. The 152Thr and 223Val residues were predicted to reside in proximity to the third and fourth extracellular loops, respectively. Together, these results establish a correlation of the four amino acid changes in the RhD protein with the expression of D(IIIa) as a partial D antigen on the RBC membrane. Since the varied nucleotides identified in D(IIIa) all pre-exist in CE, they are likely to have originated from CE by templated micro-conversion event(s). The identification of a specific nt736 C-to-G transversion in CE in the two probands suggests that 245Val may involve the expression of VS antigen.

Alternative splicing of a novel glycophorin allele GPHe(GL) generates two protein isoforms in the human erythrocyte membrane

The Henshaw antigen (synonym: He or MNS6) is carried by an altered form of glycophorin B (GPB), but the molecular basis for its variable expression or quantitative polymorphism remains largely undefined. We report here the identification and analysis of a novel glycophorin He allele, GPHe(GL), which gives rise to the expression of two protein isoforms in the erythrocyte membrane. In addition to the nucleotide changes defining the epitopic sequence of He, a single C-to-G nucleotide transversion in exon V coding for the membrane domain was found to cause aberrant RNA splicings by creating a new acceptor splice site. In addition, a T-to-G transversion at -6 position of the acceptor splice site for exon IV was identified. Both full-length and truncated transcripts of GPHe(GL) were detected as the result of partial activation of the new acceptor splice site and partial inactivation of the normal splice sites. The full-length cDNA encoded He, S, and U antigens, whereas the three truncated ones lacked either the sequence for S and U antigens or a large portion of the membrane domain or both. The GPB gene on the other chromosome was apparently normal and its transcript encoded N, s, and U antigens. These results correlate alternative RNA splicing with the expression of two GPHe isoforms and thus delineate a new mechanism for the phenotypic diversity of membrane glycophorins.

Delayed enhanced nitric oxide-mediated coronary vasodilation following brief ischemia and prolonged reperfusion in conscious dogs

The goal of this study was to determine both the early and delayed effects of a brief (10-minute) coronary artery occlusion (CAO) and prolonged (5-day) reperfusion (CAR) on coronary endothelial function. Fourteen mongrel dogs were chronically instrumented to measure aortic and left ventricular pressures, wall thickness, and left circumflex coronary blood flow (CBF). Before CAO and during CAR, coronary vascular reactivity was investigated by 15-second CAO and subsequent reactive hyperemia (RH) and by the selective intracoronary infusion of acetylcholine (ACh, 10 micrograms/min) and bradykinin (BK, 2.5 micrograms/min), endothelium-dependent vasodilators, and sodium nitroprusside (SNP, 40 micrograms/min), an endothelium-independent vasodilator. CBF responses to ACh and BK began to increase after 6 hours of CAR, reached a peak after 1 to 2 days of CAR, and then subsided over the subsequent 4 days. After 1 day of CAR, compared with before CAO, enhanced CBF responses (P < .05), associated with increased coronary sinus oxygen content, were observed for-ACh (+66 +/- 20%), BK (+74 +/- 24%), and RH (+24 +/- 5%) but not SNP (-2 +/- 10%). Production of NO metabolites (nitrate and nitrite), measured as their coronary arteriovenous differencexCBF, was significantly increased after 1 to 2 days of CAR, both at baseline (153 +/- 56%) and during BK infusion (220 +/- 76%) (P < .05). Holding CBF at pre-CAO levels during the initial CAR period did not attenuate the delayed enhanced endothelial vasodilation to ACh and BK. However, NO blockade with intracoronary NG-nitro-L-arginine blocked the enhanced coronary vasodilation to ACh and BK. Thus, in contrast to previous studies, these data indicate that brief ischemic episodes induce delayed enhanced coronary endothelial function, which is delayed in onset and prolonged in duration. This can be explained by an upregulation of coronary vascular NO production, potentially involved in the mechanism of the delayed window of preconditioning.

Percutaneous drainage in the treatment of emphysematous pyelonephritis: 10-year experience

PURPOSE

We investigated the effect of percutaneous drainage for the treatment of emphysematous pyelonephritis.

MATERIALS AND METHODS

A retrospective analysis was done of 25 patients with emphysematous pyelonephritis who were treated initially with computerized tomography (CT) guided percutaneous drainage during a 10-year period. The patients were concomitantly treated with antibiotics, fluids, and correcting blood glucose and/or ureteral obstruction. We also compared our results of percutaneous drainage to CT findings.

RESULTS

CT identified 12 patients with emphysematous pyelonephritis who had gas with little fluid and 13 who had gas with renal or perirenal fluid collections. In 20 of 25 patients (80%) antibiotic therapy combined with percutaneous drainage constituted the only treatment required. Three patients (12%) whose clinical status improved after percutaneous drainage subsequently underwent elective nephrectomy without further complications. Two patients (8%) died of multiple organ failure. There was no correlation between the gas patterns of emphysematous pyelonephritis and initial success with the antibiotics and percutaneous drainage. There were no recurrences and no complications during a followup of 1 to 10 years (mean 5). Mean duration of treatment was 5.54 weeks (range 1 to 12.6).

CONCLUSIONS

CT is an efficient imaging method for diagnosis, guiding the drainage procedures and monitoring response to percutaneous drainage of emphysematous pyelonephritis. Antibiotic therapy combined with CT guided percutaneous drainage of emphysematous pyelonephritis is an acceptable alternative to antibiotic therapy with surgical intervention.

Concomitant chemotherapy and radiotherapy for locally advanced nasopharyngeal carcinoma

BACKGROUND

The prognosis of stage III and IV nasopharyngeal carcinoma treated with radiation therapy alone is poor. To improve outcome, concomitant chemotherapy was incorporated into the treatment of locally advanced nasopharyngeal carcinoma.

METHODS AND PATIENTS

Seventy-four patients with locally advanced nasopharyngeal carcinoma were prospectively treated with a combination of concomitant chemotherapy and computerized-tomography-assisted radiotherapy at Koo Foundation Sun Yat-Sen Cancer Center, Taipei, Taiwan, between April 1990 and December 1995. The first 29 patients who had a minimum of 2 years of follow-up were included in this report. Their median interval of follow-up was 42 months. The dose of radiation was 7000 cGy given in 35 fractions. Two courses of chemotherapy, consisting of cisplatin and 5-fluorouracil, were delivered simultaneously with radiotherapy during weeks 1 and 6, and two additional monthly courses were given after radiotherapy. Included in this study were four patients with stage III and 25 patients with stage IV disease.

RESULTS

Toxicities of concomitant radiotherapy and chemotherapy were acceptable and reversible. The locoregional control rate at 50 months was 88.2%, and the disease-free survival rate was 74.6%.

DISCUSSION

Our results demonstrate an improved survival with the addition of computerized tomography treatment planning and concomitant chemotherapy to radiotherapy in the treatment of locally advanced nasopharyngeal carcinoma when compared with data in the current literature. However, a randomized trial comparing computerized-tomography-assisted radiotherapy with and without chemotherapy is necessary to confirm the contribution of chemotherapy.

Anti-D in a D-positive renal transplant patient

BACKGROUND

The detection of anti-D in a D-positive renal transplant recipient is unusual and may arise by several potential mechanisms. These include passive transfer of alloantibody and the presence of autoanti-D or alloanti-D that is due to microchimerism when the allograft is from a D-negative donor. In the latter case, overt hemolysis has been seen or suspected. The occurrence of anti-D in a D-positive renal transplant recipient without hemolysis, which is most likely attributable to microchimerism, is reported.

CASE REPORT

A 51-year-old group O, D-positive woman, who was serologically HLA type A1, A2; B8, B44; DR3, DR6, DR52; DQ1, DQ2, underwent the transplantation of a kidney from a cadaveric donor who was serologically HLA type A1, A2; B8, B44; DR13, DR17, DR52; DQ1, DQ2. The donor was known to be D-negative and immunized to D. No blood components or derivatives were administered at the time of organ graft. Ten weeks after the transplant, the direct antiglobulin test was positive in the recipient, and anti-D was eluted. Polymerase chain reaction amplification using primers to distinguish DR13 (donor) from DR14 alleles (recipient split of DR6) in the peripheral blood showed the recipient to be DR14. No DR13 could be detected, and thus microchimerism could not be confirmed. However, in the peripheral blood, GM and KM allotyping of the serum (GM A,F,X B,G and KM 1,3) and eluate (G1M F, KM 3) showed a pattern of allotypes most consistent with an alloantibody. Eleven months after transplantation, the graft continued to function; the direct antiglobulin test was still positive, and elution of anti-D persisted.

CONCLUSION

This case of anti-D in a D-positive renal transplant recipient is attributed to microchimerism, despite the lack of confirmation by genotypic analysis of the peripheral blood. It raises the possibility that microchimerism may be a more common phenomenon in solid allograft recipients than is realized.

Molecular insights into the Rh protein family and associated antigens

The Rh (Rhesus) protein family is expressed mainly in cells of erythroid lineage and, currently, is thought to comprise Rh30 (RhD and RhCE) polypeptides and Rh50 glycoprotein. As multipass integral membrane proteins, Rh30 and Rh50 are closely related by clear sequence homology and similar membrane topology, functioning respectively as the carrier and coexpressor of the Rh blood group antigens. The past year has seen a further accumulation of evidence concerning the molecular basis of Rh antigen expression, a major expansion of the catalogue of Rh allelic polymorphism, and significant progress in defining the genetic defects underlying the Rh deficiency syndrome. Now the gene structure for many Rh variants has been determined and some information obtained on the mechanisms of Rh genetic diversity and on the factors affecting the formation and surface presentation of discrete antigenic epitopes. The identification of various mutations in the Rh50 gene associated with the Rhnull and Rhmod phenotypes establishes RH50 as a suppressor for the RH locus and Rh50 protein as a critical component of the Rh complex. These new advances have broadened our understanding of the molecular biology of the Rh protein family and provided insight into the functional role of the Rh complex in maintaining the architecture of the erythrocyte membrane.

Leiomyosarcoma of the left atrium: a case report

Primary malignant cardiac tumors are uncommon, and cardiac leiomyosarcoma is extremely rare. We reported a case of left atrial (LA) leiomyosarcoma with unusual clinical manifestations. A 28-year-old female presented with unknown cause of fever, body weight loss and anemia for two months. Echocardiography and magnetic resonance image study disclosed a 5 x 3 x 3.6 cm3 lobulated mass in the LA with invasion to its posterior wall. Histologic and immuno-histochemical studies of the resected specimen revealed a picture of leiomyosarcoma. The patient improved after surgical resection and post-operative chemotherapy. The literature was reviewed with a discussion of the clinical manifestations, diagnosis and treatment strategy of this rare tumor. Diagnosis of LA leiomyosarcoma is frequently delayed to make a very poor prognosis. Postoperative chemotherapy should be considered because of highly possible incomplete resection. However, an optimal treatment regimen remains unknown.

The glycophorin A gene family in gorillas: structure, expression, and comparison with the human and chimpanzee homologues

Homologues of MN blood group antigens, encoded by members of the glycophorin A (GPA) gene family, are expressed in man, anthropoid apes, and some species of Old World monkeys. Previous studies had shown that a three-gene framework, most closely related to that in man, is present in the chimpanzee. Here we report the genomic structure, transcript map, and protein expression of the GYPA locus in gorillas. Compared to the corresponding human and chimpanzee homologues, gorilla GPA, GPB, and GPB/E genes each showed a high degree of sequence identity, with the same exon-intron organization. However, the expression of exons III, IV or V encoding the extracellular or membrane domains of homologous glycophorins varied among the three species. Gorilla GPA and GPB/E genes were unique in that the former occurred in two allelic forms with or without the expression of exon III, whereas the latter contained one (psi exon III) instead of two silenced exons (psi exons III and IV). Differences from human but not chimpanzee GPA also included the presence of a hybrid M/N epitope and the absence of the sequon for N-glycosylation. Owing to the retention of a functional exon III, gorilla GPB was more similar to chimpanzee GPB than human GPB. A transspecies allele was identified in the gorilla that gave rise to the Henshaw (He)-like antigen similar to that found in man. These results provide further insight into the model for evolution of the GPA gene family, indicating that the mechanisms underlying inter- and intraspecific polymorphism of glycophorins could predate the divergence of gorillas as the consequence of gene duplication and diversification.

Influence of furosemide on the ureteric damage in a rat model of obstructive uropathy

Furosemide has been used in the diuretic renography and diuretic radionuclide scan to evaluate the severity of hydroureter and hydronephrosis. To elucidate the influence of furosemide on obstructed ureters, unilateral ligation of ureter was performed in 45 rats. Twenty-four of the rats received intramuscular injections of furosemide (6 mg/kg/day) after the third day postligation. Eight rats were sacrificed for examination on days 7, 10 and 14 after ligation, respectively. The remaining 21 untreated rats were also sacrificed for comparison. The severity of hydroureter and hydronephrosis in the ligated side of the furosemide-treated rats was significantly higher than that of the untreated rats. However, the histological changes in the treated and untreated rats showed no significant difference. The ultrastructural alterations aggravated along the course of ureteric obstruction. Intriguingly, the ultrastructural changes were significantly milder in the treated rats. We conclude that the administration of furosemide might increase the severity of hydroureter, but it does not accelerate the ureteric damage of the obstructed ureters.

Viral hepatitis in continuous ambulatory peritoneal dialysis patients in an endemic area for hepatitis B and C infection: the Taiwan experience

The prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), and their associations in 64 continuous ambulatory peritoneal dialysis (CAPD) patients (30 males and 34 females) were evaluated. A comparison was also made with 526 normal controls (266 males and 260 females). Forty-seven (75%) CAPD patients were anti-HBc positive, with no significant difference to the control group (81.9%). This probably reflects acquisition of HBV infection by CAPD patients before initiation of chronic dialysis therapy in a region hyperendemic for HBV. On the contrary, 11 (17.2%) CAPD patients were anti-HCV positive and 8 (15.2%) were seropositive for both anti-HBc and anti-HCV-much greater prevalence rates compared to those of the control group. The prevalence of anti-HCV correlated with the history and numbers of blood transfusion, and the length of time on previous hemodialysis. A similar correlation occurred in patients with both anti-HBc(+) and anti-HCV(+). In conclusion, in an HBV endemic area such as Taiwan, the prevalence of coexisting HBV and HCV infection in CAPD patients depends on the latter.

Rigid bronchoscopy and jet ventilation in an extremely low birthweight infant

Until recently, rigid bronchoscopy was considered too risky for premature infants. We report a 658 g infant with life-threatening mediastinal shift due to right pulmonary atelectasis. Rigid bronchoscopy revealed tenacious mucous plugs in the right main bronchus. The collapsed lung was successfully reinflated after bronchial lavage with a rigid bronchoscope, with the help of intermittent high-frequency jet ventilation (HFJV). The infant's mediastinal shift was reversed and the vital signs became stable. In our experience, rigid bronchoscopy combined with HFJV is a valuable diagnostic and therapeutic procedure for very small premature infants.

Genetic recombination at the human RH locus: a family study of the red-cell Evans phenotype reveals a transfer of exons 2-6 from the RHD to the RHCE gene

The human RH locus appears to consist of two structural genes, D and CE, which map on the short arm p34-36 of chromosome 1 and specify a most complex system of blood-group genetic polymorphisms. Here we describe a family study of the Evans (also known as "D..") phenotype, a codominant trait associated with both qualitative and quantitative changes in D-antigen expression. A cataract-causing mutation was also inherited in this family and was apparently cotransmitted with Evans, suggesting a chromosomal linkage of these two otherwise unrelated traits. Southern blot analysis and allele-specific PCR showed the linkage of Evans with a SphI RFLP marker and the presence of a hybrid gene in the RH locus. To delineate the pattern of gene expression, the composition and structure of Rh-polypeptide transcripts were characterized by reverse transcriptase-PCR and nucleotide sequencing. This resulted in the identification of a novel Rh transcript expressed only in the Evans-positive erythroid cells. Sequence analysis showed that the transcript maintained a normal open reading frame but occurred as a CE-D-CE composite in which exons 2-6 of the CE gene were replaced by the homologous counterpart of the D gene. This hybrid gene was predicted to encode a CE-D-CE fusion protein whose surface expression correlates with the Evans phenotype. The mode and consequence of such a recombination event suggest the occurrence, in the RH locus, of a segmental DNA transfer via the mechanism of gene conversion.

On the bilayer phase transition temperatures for monoenoic phosphatidylcholines and phosphatidylethanolamines and the interconversion between them

The dependence of the phase transition temperature, Tm, on the structural parameters of the lipid molecule has been firmly established for lipid bilayers composed of saturated phosphatidylcholines (PC) or phosphatidylethanolamines (PE). It is from such a dependence that conversions of Tm values from saturated PC to PE and vice versa have been successfully demonstrated. In this communication, similar chain-melting-structure relationships are sought for monoenoic PC and PE in which the long hydrocarbons linked at the sn-1 and sn-2 positions are saturated and cis-mono-unsaturated chains, respectively. Specifically, various molecular species of monoenoic PC and PE were first semisynthesized and their Tm values were subsequently determined by high-resolution differential scanning calorimetry. Based on the crankshaft-like kink motif model, the synthesized monoenoic PC and PE can each be divided into two groups, each group being characterized by three structural parameters. For each group of monoenoic PC or PE, a specific equation correlating the changes in Tm with variations in the structural parameters was derived using the multiple regression analysis. Furthermore, within each group of lipids including both PC and PE, an explicit equation describing the interconversion of Tm values between PC and PE with the same fatty acyl chain composition was established. The present work not only extends the earlier work relating the chain-melting temperature of saturated PC and PE to their structural parameters, but also indicates that the basic topology of the sn-2 mono-unsaturated acyl chain of PC and PE in the gel-state bilayer can be approximated by the crankshaft-like kink motif with the longer segment being packed much more orderly than the shorter segment.

Alteration of RH gene structure and expression in human dCCee and DCW-red blood cells: phenotypic homozygosity versus genotypic heterozygosity

This report describes a comparative study on the dCCee and DCW-red blood cells devoid of RhD and CcEe antigens, respectively. Southern blots showed that the two variants carried opposite deletions in the D and non-D (CcEe) genes. Rh haplotyping and exon polymerase chain reaction (PCR) assay indicated that the deletions did not extend beyond the 5' region upstream from exon 1 or the 3' region downstream from exon 10 of the respective genes. This was confirmed by finding intact promoters and 3' untranslated regions in both D and non-D genes in each variant. Reverse transcriptase-PCR and cDNA sequencing showed the expression of two transcripts in each cell type. In dCCee cells, one transcript was the regular Ce form and the other occurred as a D-Ce-D hybrid whose Ce sequence spanned exons 2 through 9. In DCW-cells, the two transcripts were derived from reversely arranged hybrid genes, ie, the CW-D gene was formed by fusion of CW exon 1 with D exons 2 through 10, whereas the reverse product was formed by fusion of D exons 1 through 9 with non-D exon 10. These results indicated that DNA deletion and recombination had occurred in either cis or trans configuration and involved both RH loci in the dCCee or DCW-genome. Identification of such compound alterations correlates the genotypes with phenotypes and explains the lost Rh antigenic expression. A reinvestigation of gene organization also led to the reassignment of several 5' and 3' splice sites. Together, this study not only shows the complexity of Rh phenotypic diversity, but also points to the importance of concurrent analysis of genomic structure and transcript expression in deciphering the underlying genetic mechanisms.

Perioperative alterations of the thromboelastography in patients receiving one-stage bilateral total knee arthroplasty

BACKGROUND

Total knee arthroplasty is associated with activation of coagulation and fibrinolytic system in the perioperative period. The coagulation and fibrinolytic activation in one-stage bilateral total knee arthroplasty has not been described before. Thromboelastography is a real-time aid in the monitoring of coagulation and is clinically valuable in the evaluation of whole blood hemostasis. We evaluated the coagulation and fibrinolysis system activation during and after one-stage bilateral total knee arthroplasty by thromboelastography.

METHODS

Twenty patients, ASA class I-II, undergoing one stage bilateral total knee arthroplasty were included in this study. All patients received continuous spinal anesthesia with isobaric 0.2% bupivacaine. Arterial blood samples were obtained for thromboelastography in the following sequences (1) after induction of anesthesia (baseline), (2) 20 min after releasing tourniquet of the first leg (3) 20 min after releasing tourniquet of the second leg, (4) 2 h postoperatively, (5) 24 h postoperatively.

RESULTS

There was a significant shortening of reaction time (R value) after deflation of the first leg tourniquet, and a further decrease of R value after deflation of the second leg tourniquet and two hours postoperatively. The perioperative change of coagulation time was similar to that of R value. The maximum amplitude decreased after releasing tourniquet of the second leg and two hours postoperatively.

CONCLUSION

The activation of coagulation, as monitored by thromboelastography, is predominant in one-stage bilateral total knee arthroplasty after releasing tourniquet of the second leg and returns to baseline 24 h postoperatively.

Expression and quantitative variation of the low-incidence blood group antigen He on some S-s-red cells

BACKGROUND

Red cells devoid of glycophorin B (GPB)-borne S, s, and U antigens are classified as an S-s-U- or S-s-U variant (U+var) and can arise from deletion and nondeletion genetic backgrounds. In nondeletion forms of S-s-U-, little information is available on whether the altered GPB gene (GYPB) is expressed in red cells.

STUDY DESIGN AND METHODS

Red cells classified as S-s-U- or S-s-U+var were tested with anti-U, anti-U/GPB, anti-He, and anti-N by hemagglutination. Selected samples were tested by flow cytometry, immunoblotting, and polymerase chain reaction amplification using allele-specific primers.

RESULTS

He (MNS6) was found on 23 percent (20/87) of samples. These and another 21 of the 87 samples were agglutinated by an anti-U/GPB reagent; this indicated that approximately 50 percent of S-s-samples possessed GPB variants. The strength of He varied among the samples. Genomic polymerase chain reaction with allele-specific primers showed the presence of expected DNA GPB-like products encoding He. Immunoblotting showed that He was carried on a membrane component with a relative molecular mass indistinguishable from that of GPB.

CONCLUSION

The finding of He on S-s- red cells provides direct evidence for the presence of an altered form of GPB in red cells previously thought to be devoid of this glycophorin. Quantitative variation in He antigen expression was observed in a subset of S-s- red cells.

Characterization of a new human transitional cell carcinoma cell line from the renal pelvis, RTCC-1/KMC

Tumors of the renal pelvis and ureter are relatively common malignancies in Taiwan. Studying the genetic or biochemical aberrations is a feasible pursuit that has great potential to further our understanding of urothelial cancer and may provide clinically valuable information. We now report a new long-term culture (RTCC-1/KMC) of human TCC derived from the renal pelvis, which is aimed to be used as a target for those studying in this field. The cultured cells exhibited anchorage independence and loss of contact inhibition. Chromosomal analysis revealed an aneuploidy line with a modal number of 50. Population doubling time was about 36 hours at the third passage. Expression of keratin proteins confirmed its epithelial origin. The genetic markers of the RTCC -1/KMC cell line were HLA-A11, B46, B60, Cw1, Cw7, DRw12 and DRw16. The human papillomavirus and herpes simplex virus genomes were not found in this cell line.

Analysis of sequence polymorphism of a major mite allergen, Der p 2

BACKGROUND

The major house dust mite allergen Der p 2 has been regarded as an important allergen involved in the immunopathogenesis of allergic asthma and eczema.

OBJECTIVES

To determine the degree of sequence polymorphism exists in Der p 2 at both the genomic DNA and cDNA levels.

METHODS

Isolation of cDNA clones was performed by screening the cDNA libraries with Der p 2 cDNA probe and the genomic sequences for Der p 2 were obtained by PCR amplification from environmental dust mites with Der p 2-specific primers. DNA sequencing was carried out by the dideoxynucleotide chain termination method. The study of Der p 2 isoforms was performed by 2-D gel immunoblot analysis using mouse anti-Der p 2 serum.

RESULTS

In this study, we have characterized the sequences of three different gene alleles coding for the major house dust mite allergen Der p 2 at the cDNA level. The translated polypeptides from these clones differed from each other by 3-4 amino-acid residues. These polymorphic residues determined were also found in Der f 2 and they were located in regions containing T-epitopes. In addition, the genomic DNA sequences of Der p 2 which were obtained by PCR amplification using the environmental mites isolated from Taiwan and Australia have helped to confirm the authenticity of the polymorphisms detected in the cDNA clones generated from CSL cultured mites. Furthermore, 2D- immunoblot analysis indicated that there were at least 10 different isoforms (p 1 values range from greater than 7.0-5.9) of Der p 2 proteins produced by CSL cultured mites.

CONCLUSION

The results showed that there was a small but significant degree of sequence polymorphisms exists in Der p 2 gene alleles. Interestingly, the polymorphic residues were found in regions containing previously determined T-epitopes. The polymorphism data reported here will be important for the understanding of the immune responses of mite allergens as well as for the development of the peptide-based immunotherapeutic reagents for mite allergy.

Muscle strength after successful total knee replacement: a 6- to 13-year followup

This study investigated the long term results of muscle strength of the knee joint after total knee replacement. Isokinetic testings of 120 degrees and 180 degrees per second and isometric testings at 30 degrees and 60 degrees knee flexion were studied on 1 healthy group and 3 groups of patients 6 to 13 years after total knee arthroplasty with prosthesis designs of total condylar, low contact stress meniscal bearing, or low contact stress rotating platform. The total condylar and low contact stress rotating platform prostheses were designed for use with a cut posterior cruciate ligament, whereas the low contact stress with meniscal bearing type was designed for use with a retained posterior cruciate ligament The muscle strength ratios of hamstring to quadriceps were compared among the prosthetic designs and there were no statistical differences among patient groups. Whether the posterior cruciate ligament was cut or retained did not affect the relative muscle strength of the quadriceps and hamstring. All hamstring to quadriceps ratios from the isokinetic testings of these 3 prostheses design groups were greater than those of the healthy group, but were quite close to those of patients with cut anterior cruciate ligaments or with lower levels of daily activity. The hamstring to quadriceps ratios after successful total knee replacement were not the same as those of the healthy group even after long term (6-13 years) functional adaptation.

Extra-articular tuberculous osteomyelitis. A report of 11 cases

Eleven cases of extra-articular tuberculous osteomyelitis are presented. Eight of the patients were children. Ten were treated by curettage and chemotherapy and the diagnosis proved by histology or positive culture of the tubercle bacillus. One case was diagnosed because she also had tuberculous salpingitis, and she was treated by chemotherapy alone. A high index of suspicion is needed for early diagnosis. Treatment gave satisfactory results.

Blood and central venous pressure responses after serial tourniquet deflation during bilateral total knee replacement

Thirty-five patients who underwent one-stage bilateral total knee replacement were included in this study to determine whether there was any difference in hemodynamic effects following the deflation of the first and second tourniquets. The values of hemodynamic variables were not significantly different immediately before either the first or the second tourniquet release as compared to preoperative values. The changes in heart rate after the release of the first and second tourniquets showed similar patterns. The systolic and diastolic blood pressure decreased significantly after deflation of the first and second tourniquets. However, the decrease was more marked after the second tourniquet deflation. The level of central venous pressure decreased significantly after the release of the first and second tourniquets but the patterns of change were not significantly different. The need for administration of ephedrine was also higher after the deflation of the second tourniquet than after the first. We conclude that the blood pressure changes after the second tourniquet deflation are more pronounced than those following the first tourniquet deflation. Anesthesiologists must be aware of this phenomenon and prevent marked hemodynamic changes that could be detrimental to high-risk patients.

Perioperative changes of plasma endothelin-1 concentrations in patients undergoing cardiac valve surgery

Twenty-one patients who underwent cardiac valvular replacement procedures were studied to determine the perioperative changes of plasma endothelin-1 (ET-1) concentration and disposition of ET-1 in the pulmonary and systemic vasculature between patients with elevated (over 20 mmHg) mean pulmonary artery pressure and patients with normal pulmonary artery pressure. The overall profile alterations of plasma ET-1 concentration did not differ between the two groups of patients. The plasma ET-1 levels in the pulmonary artery and right atrium were significantly higher in patients with high pulmonary artery pressure than in patients with normal pulmonary artery pressure. Before cardiopulmonary bypass, significant pulmonary extraction of the plasma ET-1 existed in patients with high pulmonary artery pressure but the pulmonary extraction was not seen after bypass. There was no transpulmonary difference of the plasma ET-1 concentration in patients with normal pulmonary artery pressure either before or after bypass. The high levels of ET-1 in the pulmonary circuit and the pulmonary extraction of the ET-1 in patients with high pulmonary artery pressure might be a protective mechanism for rheumatic valvular patients with elevated pulmonary artery pressure.

[Pre- and intra-operative administration of epidural morphine provides good postoperative pain relief after laminectomy]

BACKGROUND

To evaluate the postoperative analgesic effect of epidural morphine administered at different timing in lumbar spine surgery.

METHODS

Eighty-four patients who were scheduled for elective lumbar spine surgery were randomized in three groups. Seventeen patients in group I who received non-steroid analgesics postoperatively (diclophenac sodium 50 mg, iv, q4h) served as control while thirty-six patients in group II who received single dose epidural morphine 3 mg in combination with 10 ml 2% lidocaine given at the lesion site (L4-5 or L5-S1) just before general anesthesia and thirty-one patients in group III who received 3 mg morphine in combination with 3 ml 2% lidocaine administered to the targeted epidural space by means of slow drippings just before wound closure were studied subjects.

RESULTS

During the first 24 h postoperatively, the patients in group II and group III suffered a pain which was significantly less in intensity as compared with those in group I (p < 0.05). We used the 10 cm visual analog pain score (VAS) to scale post-operative pain with "no pain" and "worst pain" respectively anchored at 0 and 10 cm. The incidence of side effects such as pruritus, nausea and vomiting was higher in group II and III than in group I. We did not evaluate the occurrence of urinary retention because routine retention urinary catheterization in all patients hampered us to do so. There were no significant differences in the quality and duration of analgesia between group II and III. Respiratory depression of clinical significance was not observed. Neither decrease in oxygen saturation below 92% registered on pulse oximetry nor decrease in respiratory rate below 12 cycles/min was found in the PACU.

CONCLUSIONS

Preoperative or intraoperative administration of epidural morphine could provide satisfactory analgesia in lumbar spine surgery during the first 24 h postoperatively.

Human red blood cell Wright antigens: a genetic and evolutionary perspective on glycophorin A-band 3 interaction

The Wright (Wra/Wrb) blood group polymorphism is defined by an allelic change (Lys658Glu) in the band 3 protein; nevertheless, the Wrb antigen apparently requires glycophorin A (GPA) for surface presentation. To gain insight into the structural basis for this protein-protein interaction and delineate its relationship with Wrb antigen expression, we investigated GPA and band 3 sequence polymorphisms occurring in rare humans and nonhuman primates. The lack of GPA or amino acid residues 59 through 71 of GPA results in the absence of Wrb from human red blood cells (RBCs) exhibiting the MkMk, En(a-), or MiV phenotype. However, the SAT homozygous cells carried a Glu658 form of band 3 and a hybrid glycophorin with the entire GPA extramembrane domain from residues 1 through 71, yet expressed no Wrb antigen. This finding suggests that formation of the Wrb antigenic structure is dependent on protein folding and that the transmembrane junction of GPA is important in maintaining the required conformation. Comparative analyses of GPA and band 3 homologues led to the identification in the interacting regions of conserved and dispensable amino acid residues that correlated with the Wrb positive or negative status on nonhuman primates. In particular, the chimpanzee RBCs cells expressed Wrb and the Glu658 form of band 3, which is identical to humans, but their GPA contained the Gly rather than Arg residue at position 61. Taken together, the results suggest that (1) Arg61 of GPA and the proposed Arg61-Glu658 charge pair are not crucial for Wrb antigen exhibition and (2) the role of GPA for interaction with band 3, including Glu658, probably involves a number of amino acid residues located in the alpha-helical region and transmembrane junction.

Dietary fat influences Ia antigen expression, cytokines and prostaglandin E2 production of immune cells in autoimmune-prone NZB x NZW F1 mice

To elucidate further the influences of dietary fat on autoimmune diseases, two groups of NZB/W F1 mice were fed with diets containing 200 g dietary fat/kg and 50 g dietary fat/kg (control) respectively. The difference in energy intake between these two groups was compensated with carbohydrate. Mice were bled regularly every month and some of them were killed for in vitro experiments after 5 months experimental diets. Higher immunoglobulin (Ig)M and IgG anti-double stranded DNA antibody levels, shortened life span and worsened proteinuria were noted in mice fed on the high-fat diet compared with those fed on 50 g dietary fat/kg. Phenotypic analyses of spleen cells and peritoneal exudate cells showed that the percentage of CD5+ B cells and the mean fluorescent intensity of major histocompatibility molecules on the surface of both types of cells were higher in mice fed on the high-fat diet. In general, higher type 2 T-helper cell activity was noted in mice fed on the high-fat diet. In addition, cytokines such as interleukin-6, tumour necrosis factor-alpha and prostaglandin E2 (PGE2) produced by lipopolysaccharide-stimulated peritoneal exudate cells were also higher in the high-dietary-fat group. These studies suggest that high dietary fat and its related PGE2 level might have a critical effect on the frequency of CD5+ B cells, cytokine production, macrophage function and subsequent autoimmune regulation in autoimmune mice.

The regulation mechanism of c-jun and junB by human papillomavirus type 16 E5 oncoprotein

In this study, we show that HPV-16 E5 induced anchorage-independent growth in immortalized human epidermal keratinocytes and that HPV-16 E5 in human keratinocytes had higher expression of c-jun and junB; also, we investigated the role of transcriptional initiation pathways in the expression elevation. In addition, Ras-dependent pathway, as well as PKC-dependent pathway, leads to HPV-16 E5-induced c-jun gene expression.

A replication-deficient adenovirus enhances liposome-mediated nucleic acid transfer into a stable cell line expressing T7 RNA polymerase

Liposome-mediated transfer of nucleic acids into a cell line expressing bacteriophage T7 RNA polymerase was enhanced by addition of a replication-deficient adenovirus (Ad5-259A) to transfection mixtures. Increasing quantities of Ad5-259A resulted in a dose-related (up to 30-fold) enhancement of reporter gene activity expressed in BT7-H cells transfected with plasmid DNA containing the reporter sequence fused to the internal ribosome entry site of encephalomyocarditis virus. Similarly, Ad5-259A enhanced reporter gene expression 7-fold following transfection of DNA containing the reporter sequence under transcriptional control of the Rous sarcoma virus long terminal repeat. Addition of Ad5-295A to transfection mixtures increased the proportion of cells staining positively for reporter gene activity, from 2 to 25% when the reporter was expressed via the T7 polymerase and from 20 to 50% when the reporter was under the control of a eucaryotic promoter. Thus, Ad5-259A enhanced reporter protein activities expressed by cytoplasmic T7-directed transcription and cap-independent initiation of translation, or nuclear transcription and cap-dependent translation. Transfection enhancement was blocked by neutralizing antibody to Ad5, and is most likely related to the endosome-disrupting activities of the virus. Adenovirus enhancement of liposome-mediated transfection provides a useful method for efficient nucleic acid transfer into eucaryotic cells.

Total knee replacement with minimally constrained prostheses in spontaneous bony ankylosis

Total knee replacement has been carried out in the 4 knees of 2 patients for spontaneous bony ankylosis. Minimally constrained prostheses were used because the ligaments were usually intact and the patellofemoral and tibiofemoral joint lines could be re-established. The approach and repair was by a V-Y quadricepsplasty. Satisfactory results were obtained.

Efficacy of ultrafiltration in removing inflammatory mediators during pediatric cardiac operations

BACKGROUND

Conventional and modified ultrafiltration was used in pediatric cardiac operations to reduce volume overload and total body water. The purpose of this study was to compare the efficacy of these techniques in removing inflammatory mediators during cardiopulmonary bypass.

METHODS

Fifty pediatric patients undergoing cardiac operations were randomized into a modified or conventional ultrafiltration group. Blood samples were obtained before and after ultrafiltration to assess the plasma concentrations of leukocyte elastase, tumor necrosis factor-alpha, interleukin-6, and interleukin-8.

RESULTS

Except for plasma concentrations of tumor necrosis factor-alpha in the modified ultrafiltration group, the plasma concentrations of all the mediators measured increased after ultrafiltration in both groups of patients. The volume of ultrafiltrate and the total amounts of tumor necrosis factor-alpha and interleukin-6 removed by ultrafiltration were significantly greater in the modified group. The concentrations of mediators in the ultrafiltrate and the ratio of ultrafiltrate to plasma concentrations of the mediators did not differ between the groups. Ultrafiltration was more efficient in removing tumor necrosis factor-alpha than the other mediators.

CONCLUSIONS

The efficacy in removing the inflammatory mediators generated during cardiopulmonary bypass did not differ between modified and conventional ultrafiltration.

Molecular definition of red cell Rh haplotypes by tightly linked SphI RFLPs

The Rh blood group system of human red cells contains five major antigens D, C/c, and E/e (the latter four designated "non-D") that are specified by eight gene complexes known as Rh haplotypes. In this paper, we report on the mapping of RH locus and identification of a set of SphI RFLPs that are tightly linked with the Rh structural genes. Using exon-specific probes, we have localized the SphI cleavage sites resulting in these DNA markers and derived a comprehensive map for the RH locus. It was found that the SphI fragments encompassing exons 4-7 of the Rh genes occur in four banding patterns or frameworks that correspond to the distribution and segregation of the common Rh haplotypes. This linkage disequilibrium allowed a genotype-phenotype correlation and direct determination of Rh zygosity related to the Rh-positive or Rh-negative status (D/D, D/d, and d/d). Studies on the occurrence of SphI RFLPs in a number of rare Rh variants indicated that Rh phenotypic diversity has taken place on different haplotype backgrounds and has arisen by diverse genetic mechanisms. The molecular definition of Rh haplotypes by SphI RFLP frameworks should provide a useful procedure for genetic counseling and prenatal assessment of Rh alloimmunization.

Improvement of arterial oxygenation by selective infusion of prostaglandin E1 to ventilated lung during one-lung ventilation

BACKGROUND

One-lung anesthesia provides a better surgical field for thoracic procedures but also impairs the arterial oxygenation and venous admixture. During one-lung ventilation, pulmonary vasoconstriction is assumed to be present within both ventilated and collapsed lungs. We propose that arterial oxygenation could be optimized by offsetting the vasoconstriction within the microcirculation of ventilated lung.

METHOD

In an anesthetized dog model, incremental doses of prostaglandin E1 (PGE1) were selectively infused into the main trunk of the pulmonary artery of the ventilated lung after one-lung ventilation for 60 min (PGE1 group, n = 9). Arterial oxygenation and calculated venous admixture (Qs/Qt) was also assessed in a time-course control group (Control group, n = 5). During two-lung ventilation (FIO2: 0.66), arterial PO2 and venous admixture was 44.2 +/- 3.5 kPa and 10.7 +/- 2.3%, respectively. One-lung ventilation (FIO2: 0.66) with left lung collapsed reduced arterial PO2 to 11.6 +/- 1.7 kPa and increased venous admixture to 40.7 +/- 5.8% (P<0.001). Venous O2 tension also decreased from 6.3 +/- 0.7 kPa to 5.0 +/- 0.6 kPa with a slight increase in mean pulmonary artery pressure and pulmonary vascular resistance (P<0.05).

RESULTS

During selective infusion of PGE1 at a dose of 0.04 to 0.2 mu g kg-1 min-1, there was a dose-dependent improvement in arterial PO2 with a parallel reduction of venous admixture during one-lung ventilation. Arterial PO2 increased to a maximum of 23.0 +/- 4.3 kPa, and the venous admixture decreased significantly to a minimum of 27.4 +/- 4.2% by PGE1 at a dose of 0.04-0.4 mu g kg-1 min-1 (P<0.01). PGE1 resulted in a small increase in cardiac output and decreases of pulmonary pressure and pulmonary vascular resistance at a relatively high dose of 0.4 mu g kg-1 min-1 during selective infusion (P<0.05).

CONCLUSIONS

These results suggest that a selective pulmonary artery infusion of PGE1 to the ventilated lung within the dose range of 0.04-0.4 mu g kg-1 min-1 is practical and effective to improve arterial oxygenation and reduce venous admixture during one-lung ventilation.

Fibroadhesive form of tuberculous peritonitis: chyloperitoneum in a patient undergoing automated peritoneal dialysis

Chyloperitoneum is a rare condition in patients undergoing peritoneal dialysis. We report here a patient who developed chylous ascites during the course of tuberculous peritonitis. The diagnosis was confirmed by cultures of dialysate and peritoneal biopsy, and laparoscopy revealed severe hyperemia and intestine adhesion. Intrinsic lymphatic obstruction and superimposed peritoneal fibrosis together might be responsible for the pathogenesis of this special presentation. Although in most cases of continuous ambulatory peritoneal dialysis, the causes of chyloperitoneum remained unknown, we suggest, from the experience of this case, that tuberculous peritonitis, especially the fibroadhesive form, should be highly suspected in any dialysis cases with chyloperitoneum. Laparoscopy should be initiated early, particularly when the culture is negative for common pathogens or when the patient responds poorly to the usual antimicrobial agents.

Recent experience of penile fracture (1989-1993)

Penile fracture is an uncommon injury in the genitourinary organ which occurs following a blunt injury on the rigid penis. Penile fracture with urethral injury is even rarer. A total of 11 new patients with penile fracture were treated at our institution from 1989 to 1993. All of these injuries occurred during sexual intercourse and received immediate surgical repair to preserve the sexual function. Only one patient with complete transection of the urethra received end-to-end anastomosis of the urethra. Unfortunately, he suffered from urethral-cutaneous fistula ten days later. Suprapubic urinary diversion was performed in 3 patients with partial urethral tearing, and they enjoyed satisfactory outcomes during the limited follow-up. Immediate surgical repair of tunica albuginea is recommended for preserving penile function. If associated with partial urethral tear, suprapubic urinary diversion is sufficient to treat urethral lesions.

Differential induction and regulation of c-jun, junB, junD and c-fos by human papillomavirus type 11 E5a oncoprotein

The E5a gene of human papillomavirus type 11 (HPV-11) is a transforming oncogene. In this study, we investigated the mechanism of E5a induced transformation. Our results show that the expression of c-jun and junB, but not junD, was activated by HPV-11 E5a in NIH 3T3 cells and human epidermal keratinocytes. However, the expression of c-fos was activated by E5a in NIH 3T3 cells, but not in keratinocytes. We further investigated the mechanism of c-jun and junB induction by E5a. The amount of c-jun and junB RNAs correlated with the amount of E5a RNA in the heavy metal inducible system. E5a constitutively activated the expression of c-jun and junB at the initiation of transcription level. In addition, analyses of the effect of serum on c-jun expression in E5a transformed human epidermal keratinocytes show that EGF might have a stimulatory effect on c-jun gene expression in E5a expressing keratinocytes.

An unusual testicular metastasis from transitional cell carcinoma of the ureter: a case report

Testicular tumor metastasis from transitional cell carcinoma (TCC) of the ureter is very rare. Herein, we report a case who presented with a palpable mass of left testis, after he underwent radical nephroureterectomy and bladder cuff excision and adjuvant radiotherapy and chemotherapy for the TCC of left ureter tumor for 5 months. We performed left radical orchiectomy and histology revealed a TCC identical to the original ureteral tumor. In a review of the literature, we found this case was the second case of metastatic testicular tumor from the ureteral TCC. In patients presenting the symptom of a palpable testicular mass, if they are known to have a ureteral TCC, metastatic neoplasm should be considered in the differential diagnosis, even if in the absence of other systemic metastasis.

Sequence diversification and exon inactivation in the glycophorin A gene family from chimpanzee to human

In humans, the allelic diversity of MNSs glycophorins (GP) occurs mainly through the recombinational modulation of silent exons (pseudoexons) in duplicated genes. To address the origin of such a mechanism, structures of GPA, GPB, and GPE were determined in chimpanzee, the only higher primate known to have achieved a three-gene framework as in humans. Pairwise comparison of the chimpanzee and human genes revealed a high degree of sequence identity and similar exon-intron organization. However, the chimpanzee GPA gene lacks a completely formed M- or N-defining sequence as well as a consensus sequence for the Asn-linked glycosylation. In the case of the GPB gene, exon III is expressed in the chimpanzee but silenced, as a pseudoexon, in the human. Therefore, the protein product in the chimpanzee bears a larger extracellular domain than in the human. For the GPE genes, exon III and exon IV have been inactivated by identical donor splice-site mutations in the two species. Nevertheless, the chimpanzee GPE-like mRNA appeared to be transcribed from a GPB/E composite gene containing no 24-bp insertion sequence in exon V for the transmembrane domain. These results suggest a divergent processing of exonic units from chimpanzee to human in which the inactivation of GPB exon III preserved a limited sequence repertoire for diversification of human glycophorins.

Difference between in vivo and in vitro effects of propofol on defluorination and metabolic activities of hamster hepatic cytochrome P450-dependent mono-oxygenases

We have compared the in vivo and in vitro effects of propofol on cytochrome P450-dependent monooxygenase activities in hamster liver microsomes. Propofol (Diprivan) 10 mg/100 g body weight was injected i.p. twice a day for 2 weeks to induce cytochrome P450 enzymes. Liver microsomes were prepared by differential centrifugation. Metabolism of the cytochrome P450-dependent mono-oxygenase system was evaluated by measuring aniline hydroxylation, benzphetamine demethylation and benzo(a)pyrene hydroxylation. Defluorination of enflurane was assayed by detecting free fluoride metabolites. At similar concentrations as in the in vivo group, propofol in vitro exhibited concentration-dependent inhibition of metabolism of benzphetamine and benzo(a)pyrene. Aniline hydroxylation and defluorination of enflurane were inhibited to 78% of control with propofol 0.25 mmol litre-1. In propofol-treated hamsters, there was only minimal inhibitory or inductive effects on either mono-oxygenase activities or capacity for defluorination. This difference between the in vitro and in vivo effects of propofol on cytochrome P450 mono-oxygenase activities emphasizes the need for care when comparing in vitro and clinical data.

Phosphatidylcholines with sn-1 saturated and sn-2 cis-monounsaturated acyl chains. Their melting behavior and structures

Recently, we have shown by high resolution differential scanning calorimetry that the position of a cis double bond (delta-bond) in a series of 1-stearoyl-2-octadecenoyl- phosphatidylcholines can affect the phase transition temperature (Tm) or enthalpy (delta H) of the gel-to-liquid crystalline phase transition of this series of lipids in the following manner. The value of Tm (or delta H) is minimal when the delta-bond is positioned at C(11) in the sn-2 acyl chain; in addition, this value increases steadily as the delta-bond migrates toward either end of the acyl chain, resulting in a symmetrical, inverted bell-shaped profile (Wang, Z.-q., Lin, H.-n., Li, S., and Huang, C. (1995) J. Biol. Chem. 270, 2014-2023). In this communication, we have further demonstrated the inverted bell-shaped profile of Tm using 1-arachidoyl-2-eicosenoyl-phosphatidylcholines. In addition, we have extended the lipid series of 1-stearoyl-2-octadecenoyl-phosphatidylcholines to include 1-arachidoyl-2-octadecenoyl- phosphatidylcholines and 1-behenoyl-2-octadecenoyl-phosphatidylcholine, each series with a delta-bond at varying carbon position of 6, 7, 9, 11, 12, and 13. Calorimetric results obtained with these three series of lipids indicate that the inverted bell-shaped curve shifts toward higher temperatures in a nonuniform manner as the saturated sn-1 acyl chain length increases from 17 to 19 and then to 21 C-C bond lengths. Specifically, the Tm (or delta H) values are nearly identical for these cis-monoenoic lipids when their delta-bonds are positioned at C(13). Based on the height of the rotational energy barrier obtained with molecular mechanics calculations, it is evident that the rotational flexibility of the single C-C bond adjacent to the delta-bond in 1-stearoyl-2-octadecenoyl-phosphatidylcholine increases as the delta-bond migrates from C(9) to C(13). The differential scanning calorimetry results obtained with the three series of lipids can thus be attributed to an increase in the rotational flexibility of the short chain segment succeeding the C(14) atom in the sn-2 octadecenoyl chain. In this communication, we also propose that in the gel-state bilayer of sn-1 saturated/sn-2 cis-monounsaturated phosphatidylcholine the entire length of the shorter segment of the sn-2 acyl chain acts as a structural perturbing element; hence, it is mainly responsible for the large lower Tm of the monoenoic lipid relative to the saturated counterpart. Finally, two general equations relating Tm with the structural parameters of cis-monoenoic phosphatidylcholines are presented.(ABSTRACT TRUNCATED AT 400 WORDS)

The temporal relationship between the severity of hydroureter and the dynamic changes of obstructed ureters in a rat model

OBJECTIVE

To investigate dynamic changes in the obstructed rat ureter and to evaluate the usefulness of the rat model in the study of obstructive uropathy.

MATERIALS AND METHODS

Unilateral ligation of the ureter was performed in 26 rats. After ureteric ligation, four to seven rats were killed and examined after 1, 3, 7, 10, and 14 days. The severity of hydroureter and hydronephrosis was assessed by pyelography and the hydroureter-hydronephrosis index. The middle portion of the ureter was prepared for light and electron microscopic observation. Five rats which received a sham operation were also examined as controls.

RESULTS

The severity of hydroureter and hydronephrosis in the ligated ureters progressively increased during the period of obstruction (P < 0.005) and reached a maximum 10-14 days after ligation. Hypertrophy of the smooth muscle layer developed on the third day after ligation and proliferation of submucosal connective tissue occurred on the 10th day after ligation. The changes in smooth muscle and connective tissue layers also progressed consistently during ureteric obstruction (P < 0.001 and < 0.005, respectively). The number and size of granular endoplasmic reticulum and Golgi apparatus in the smooth muscle cells increased after ureteric ligation and then caveolae exocytosis developed. Deposition of collagen fibres between muscle cells became apparent later.

CONCLUSION

The rat model of hydrouropathy demonstrated a clear temporal relationship between the severity of hydroureter and the dynamic changes in the obstructed ureter and could be used as a conventional method for the study of obstructive ureter.