Rhnull disease: the amorph type results from a novel double mutation in RhCe gene on D-negative background

Rhnull disease, which includes the amorph and regulator types, is a rare genetic disorder characterized by stomatocytosis and chronic hemolytic anemia. We studied here a German family transmitting a putative amorph Rhnull disease gene and identified a rare mutation causing the loss-of-function phenotype. We analyzed the genomic and transcript structure of RH30, RH50, and CD47, the three loci thought to be most critical for expression of the Rh complex in the red blood cell membrane. We showed that in this family the Rh50 and CD47 transcripts were normal in primary sequence. However, the RH30 locus contained an unusual double mutation in exon 7 of the RhCe gene, in addition to a deletion of the RhD gene. The mutation targeted two adjacent codons in multiple arrangements probably via the mechanism of microgene conversion. One scheme entails a noncontiguous deletion of two nucleotides, [ATT(Ile322)-->AT] and [CAC(His323)-->CC], whereas the other involves a T-->C transition [ATT(Ile322)--> ATC] and a dinucleotide deletion [CAC(His323)-->C]. They caused the same shift in open reading frame predicted to encode a shortened protein with 398 amino acids. The loss of two transmembrane domains and gain of a new C-terminal sequence are likely to alter the protein conformation and impair the Rh complex assembly. Our findings establish the molecular identity of an amorph Rhnull disease gene, showing that Rh30 and Rh50 are both essential for the functioning of the Rh structures as a multisubunit complex in the plasma membrane.

Identification of a novel point mutation (Leu72Pro) in the NADH-cytochrome b5 reductase gene of a patient with hereditary methaemoglobinaemia type I

Utilizing polymerase chain reaction (PCR) related technology, we investigated the b5R gene of a Chinese patient with hereditary methaemoglobinaemia type I and found a novel missense mutation (CTC-CCC) at codon 72 in exon 3 of the gene. As the mutation generates an Apa I recognition site, homozygosity for the mutation was confirmed by restriction analysis of PCR-amplified fragments from the patient's genomic DNA. We predicted that the residue replacement of Leu with Pro of the mutant enzyme would account for the b5R deficiency in the patient. The results further confirm the genetic polymorphism of b5R gene mutations found in the RCM type I.

The telomeres of Streptomyces chromosomes contain conserved palindromic sequences with potential to form complex secondary structures

The chromosomes of the gram-positive soil bacteria Streptomyces are linear DNA molecules, usually of about 8Mb, containing a centrally located origin of replication and covalently bound terminal proteins (which are presumably involved in the completion of replication of the telomeres). The ends of the chromosomes contain inverted repeats of variable lengths. The terminal segments of five Streptomyces chromosomes and plasmids were cloned and sequenced. The sequences showed a high degree of conservation in the first 166-168bp. Beyond the terminal homology, the sequences diverged and did not generally cross-hybridize. The homologous regions contained seven palindromes with a few nucleotide differences. Many of these differences occur in complementary pairs, such that the palindromicity is preserved. Energy-optimized modelling predicted that the 3' strand of the terminal palindromes can form extensive hairpin structures that are similar to the 3' ends of autonomous parvovirus genomes. Most of the putative hairpins have a GCGCAGC sequence at the loop, with the potential to form a stable single C-residue loop closed by a sheared G:A pairing. The similarity between the terminal structures of the Streptomyces replicons and the autonomous parvoviral genomes suggests that they may share some structural and/or replication features.

Hypertrophic osteoarthropathy in nasopharyngeal carcinoma patients: two cases report

Hypertrophic osteoarthropathy (HOA) is a rheumatic disorder characterized by digital clubbing, bone pain, and arthralgia. HOA can be idiopathic or secondary to a variety of pulmonary, cardiogenic, or malignant disorders. We present 2 male patients, aged 46 and 42, with advanced nasopharyngeal carcinoma (NPC) who developed HOA 1-4 years after radiotherapy. Differential diagnosis between HOA and coexisting bone metastasis must be made with caution. We found bone scintigraphy to be the most sensitive tool to distinguish between these 2 disease. Intense symmetrical uptake of radioisotope along the cortex of long bones, so-called parallel tract sign, is typical. Plain radiographs demonstrating prominent periosteal reaction were also effective for this. The rheumatic manifestation of HOA was paraneoplastic and related to pulmonary metastasis. The clinical manifestation of the 2 patients suggested that pulmonary metastasis should be suspected in NPC patients when HOA appears.

Effects of ondansetron on postoperative emesis in Chinese children

BACKGROUND

Postoperative nausea together with vomiting (PONV) is a common adverse effect of general anesthesia. Ondansetron, a new serotonin (5-hydroxytryptamine) receptor antagonist of the subtype 3 is shown to be effective and safe in the prophylaxis and treatment of PONV. However, the clinical experiences of using ondansetron for prevention of PONV is lacking in Taiwan. The purpose of this study is to evaluate the efficacy and safety of ondansetron for prevention of PONV in Chinese children.

METHODS

Eighty pediatric patients aged from 2 to 12 years undergoing herinorrhaphy were prospectively randomized to receive either ondansetron 0.1 mg/kg or saline placebo. All patients received general anesthesia with tracheal intubation. The parents of patients were educated how to record the episodes of postoperative emesis and other complications and answer questions in the form of questionnaire. The observation period lasted for 24 h postoperatively.

RESULTS

The incidence of postoperative emesis was 55% and 10% in placebo and ondansetron group respectively. As to the severity of emetic symptoms it was milder in the ondansetron group. There was no difference in the incidence of other complications between the two groups.

CONCLUSIONS

The intravenous administration of ondansetron 0.1 mg/kg is safe and effective in reducing postoperative emesis in Chinese children undergoing herinorrhaphy surgery.

Antibody-based spot test for NADH-cytochrome b5 reductase activity for the laboratory diagnosis of congenital methemoglobinemia

NADH (reduced Coenzyme I)-cytochrome b5 reductase (b5R) is a multifunctional redox enzyme, whose deficiency causes recessive congenital methemoglobinemia. A novel procedure for the detection of b5R activity in human hemolysates was developed, in which b5R monoclonal antibodies dot-blotted on nitrocellulose membrane was used to capture and enrich b5R from hemolysates, and the captured b5R activity was subsequently visualized with the substrate 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide. Application of this simple method to the detection of b5R activity in the hemolysates from different subjects demonstrated that it was both sensitive and reliable. Our method would be useful for the laboratory diagnosis of congenital methemoglobinemia.

Torsion of a malignant undescended testis

Cryptorchid testis have a greater risk of malignant change than do normally descended testis. The undescended testis would also be susceptible to torsion by the mechanism of increase in testicular size. A 36-year-old man of torsion of malignant undescended testis is presented. He was diagnosed as having incarcerated inguinal hernia on his first visit to general surgeon due to acute left lower abdominal pain. At laparotomy, a 7.5 x 5.5 x 3.0 cm3, greyish tan color mass was found. The pathological diagnosis is choricarcinoma and teratoma, mixed germ cell tumor. We would emphasise that in any patient presenting with acute abdominal symptoms and an absent scrotal testis, the possibility of a complication of torsion of undescended testis should be considered.

Micellar electrokinetic chromatography of scopolamine-related anticholinergics

A simple micellar electrokinetic chromatography (MEKC) method is described for the separation of scopolamine N-oxide hydrobromide (SO), scopolamine hydrobromide (SH), scopolamine N-methylbromide (SM) and scopolamine N-butylbromide (SB), and for the quantitation of SH, SM and SB (using SO as an internal standard). The analysis of these drugs was performed in a phosphate buffer (30 mM; pH 7.00) with sodium dodecyl sulfate (SDS) (30 mM) as an anionic surfactant. Several parameters affecting the separation of the drugs were studied, including the concentrations of the buffer and SDS. The stability of the drugs in the phosphate buffer (pH 7.00) was also examined. Partial application of the method to the determination of scopolamine N-butylbromide in tablets proved to be feasible.

Primary intracranial leiomyoma: case report

We present a case of intracranial parenchymal leiomyoma in a 20-year-old woman with a chief complaint of numbness and a painful sensation over the right limbs for several years. CT and MRI revealed an intensely enhancing calcified mass. The patient was well, without recurrence, 2 years after surgery.

Primary synovial sarcoma of the gastrocolic ligament

A case of primary synovial sarcoma of the gastrocolic ligament is reported in a 37-year-old woman. CT showed an encapsulated intraabdominal cystic tumour with an amorphous solid component. Barium studies showed a mass at the gastrocolic ligament which elevated the gastric antrum and displaced the transverse colon downwards. This is the first report of synovial sarcoma formation in the gastrocolic ligament. This tumour may have originated from pluripotential mesenchyme.

Primary pyogenic abscess of the psoas muscle

During a six-year period, eleven persons with primary pyogenic abscess of the psoas muscle were treated at the Mackay Memorial Hospital. Five were males and six were females and their average age was 47.2 years (range 6-83 years). The abscess was identified by CT in 7 patients, MRI in 2 and ultrasonography in 1. One abscess was found during laparotomy. Treatment included extraperitoneal drainage of the abscess in 7 patients and CT guided aspiration in 3. One patient improved after antibiotic therapy and they all recovered after treatment. The diagnosis of primary pyogenic abscess requires a high index of suspicion and the best treatment is early operative drainage and administration of systemic antibiotics.

The human Rh50 glycoprotein gene. Structural organization and associated splicing defect resulting in Rh(null) disease

The Rh (Rhesus) protein family comprises Rh50 glycoprotein and Rh30 polypeptides, which form a complex essential for Rh antigen expression and erythrocyte membrane integrity. This article describes the structural organization of Rh50 gene and identification of its associated splicing defect causing Rhnull disease. The Rh50 gene, which maps at chromosome 6p11-21.1, has an exon/intron structure nearly identical to Rh30 genes, which map at 1p34-36. Of the 10 exons assigned, conservation of size and sequence is confined mainly to the region from exons 2 to 9, suggesting that RH50 and RH30 were formed as two separate genetic loci from a common ancestor via a transchromosomal insertion event. The available information on the structure of RH50 facilitated search for candidate mutations underlying the Rh deficiency syndrome, an autosomal recessive disorder characterized by mild to moderate chronic hemolytic anemia and spherostomatocytosis. In one patient with the Rhnull disease of regulator type, a shortened Rh50 transcript lacking the sequence of exon 7 was detected, while no abnormality was found in transcripts encoding Rh30 polypeptides and Rh-related CD47 glycoprotein. Amplification and sequencing of the genomic region spanning exon 7 revealed a G-->A transition in the invariant GT motif of the donor splice site in both Rh50 alleles. This splicing mutation caused not only a total skipping of exon 7 but also a frameshift and premature chain termination. Thus, the deduced translation product contained 351 instead of 409 amino acids, with an entirely different C-terminal sequence following Thr315. These results identify the donor splicing defect, for the first time, as a loss-of-function mutation at the RH50 locus and pinpoint the importance of the C-terminal region of Rh50 in Rh complex formation via protein-protein interactions.

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.