Measurement of anti-factor VIII IgG, IgG4 and IgM alloantibodies in previously untreated hemophilia A patients treated with recombinant factor VIII. Kogenate Japanese Clinical Study Group

Using enzyme-linked immunosorbent assay (ELISA), we measured anti-factor VIII immunoglobulin G (IgG), IgG4 and IgM in serum samples obtained from hemophilia A patients treated with a recombinant factor VIII (rFVIII) preparation (Kogenate). Twelve pre- and post-treatment serum samples from 3 previously untreated patients who developed an inhibitor (alloantibody) were evaluated. Both rFVIII and plasma-derived factor VIII (pdFVIII) were used as antigen. Serum samples were diluted 37.5-fold. For the measurement of IgM antibody, protein A Sephadex suspension was added to the patients' serum samples and the supernatant was assayed. Anti-human IgG, IgG4, and IgM monoclonal antibodies labelled with peroxidase were added and absorbance at 450nm was determined. The reactivity of the IgG antibody with rFVIII and pdFVIII was extremely low. Samples containing the IgG4 inhibitor with a neutralizing activity of approximately 7.5 Bethesda units (BU)/ml resulted in absorbance values of 0.451-0.551, thus demonstrating a considerably high degree of sensitivity. The correlation between the neutralizing activity and reactions of the IgG4 antibody with rFVIII and pdFVIII antigens was high, with correlation coefficients of 0.912 and 0.966, respectively. Furthermore, the correlation coefficient between the measured absorbance values for the antibody reacted with pdFVIII and rFVIII was 0.961. No correlation was found between the reactivity of IgM to rFVIII and pdFVIII.

Zonisamide: electrophysiological and metabolic changes in kainic acid-induced limbic seizures in rats

We studied the pharmacological mechanism of zonisamide (ZNS) using an electrophysiological and autoradiographical method in a limbic seizure model in rats. Limbic seizure status epilepticus was induced by a unilateral microinjection of kainic acid (KA) into the amygdala. Initially, observed seizures were limited to the side of the injected amygdala and then propagated to bilateral sensorimotor cortex. Eighty minutes after injection, secondarily generalized seizure status epilepticus was induced, with each seizure lasting approximately 30 s and recurring every 5 min. ZNS 100 mg/kg was administered intravenously (i.v.) during the generalized seizure. Forty minutes after ZNS administration, epileptic activity was observed only at the KA-injected amygdalar site and spikes were not observed in the bilateral sensorimotor cortex. We studied local cerebral glucose utilization (LCGU) after ZNS or saline administration using an autoradiographical method in the same limbic seizure preparation. In the ZNS group, LCGU decreased in the ipsilateral sensorimotor cortex and hippocampus, whereas in the controls LCGU increased in these structures. On the other hand, ZNS did not suppress the epileptic activity of the primary focus and no decrease in LCGU was observed in the KA-injected amygdala. ZNS inhibited seizure propagation from the epileptogenic focus but did not suppress the epileptic activity of the focus. Our results suggest that ZNS is effective for the treatment of secondarily generalized seizure.

Residues 484-508 contain a major determinant of the inhibitory epitope in the A2 domain of human factor VIII

The A2 domain (residues 373-740) of human blood coagulation factor VIII (fVIII) contains a major epitope for inhibitory alloantibodies and autoantibodies. We took advantage of the differential reactivity of inhibitory antibodies with human and porcine fVIII and mapped a major determinant of the A2 epitope by using a series of active recombinant hybrid human/porcine fVIII molecules. Hybrids containing a substitution of porcine sequence at segment 410-508, 445-508, or 484-508 of the human A2 domain were not inhibited by a murine monoclonal antibody A2 inhibitory, mAb 413, whereas hybrids containing substitutions at 387-403, 387-444, and 387-468 were inhibited by mAb 413. This indicates that the segment bounded by Arg484 and Ile508 contains a major determinant of the A2 epitope. mAb 413 did not inhibit two more hybrids that contained porcine substitutions at residues 484-488 and 489-508, indicating that amino acid side chains on both sides of the Ser488-Arg489 bond within the Arg484-Ile508 segment contribute to the A2 epitope. The 484-508, 484-488, and 489-508 porcine substitution hybrids displayed decreased inhibition by A2 inhibitors from four patient plasmas, suggesting that there is little variation in the structure of the A2 epitope in the inhibitor population.

Double mutations of the N-ras gene in a patient with acute myelomonocytic leukemia

We report a patient with acute myelomonocytic leukemia (AMMoL) who showed two independent point mutations of the N-ras gene at codons 12 and 13. Longitudinal analysis revealed that one mutation at codon 13 was detectable throughout his disease course and the other at codon 12 emerged as a second mutation 14 months after the diagnosis was made, at the refractory stage. Cloning to vector and subsequent sequencing confirmed that these mutations occurred in different alleles. Chromosome findings showed a simple abnormal karyotype at presentation and further karyotypic aberrations during his disease course, concomitantly with the second mutation of the N-ras gene. These findings revealed a close relationship among the disease progression, karyotypic evolution and a newly-appearing N-ras mutation.

Effect of immersion in water on linear expansion and strength of three base/liner materials

The purpose of this study was to characterize three base/liner materials in the initial stage of setting, i.e., dual-cured (light-activated glass ionomer), light-cured (light-activated glass ionomer analogue), and chemically-cured (conventional glass ionomer) materials. Changes in dimension, weight and flexural strength were examined from immediately after setting to the end of one week following immersion in water. The results obtained from these three types of material differed from each other, and showed a statistically significant correlation between changes in dimension and weight. This may be attributed to hygroscopic expansion. They also showed different flexural strength, indicating differences in the polymerization system. From these results, it appeared that marginal gaps following setting would be compensated for by hygroscopic expansion during immersion in water for one day or more. Physical properties would be favourably improved following the setting process which continues to advance during immersion in water.

Salfredins, new aldose reductase inhibitors produced by Crucibulum sp. RF-3817. I. Fermentation, isolation and structures of salfredins

New inhibitors of aldose reductase, designated salfredins A3, A4, A7, C1, C2, C3 and B11, were isolated from the fermentation broth of Crucibulum sp. RF-3817 by successive purification procedures of solvent extraction, silica gel column chromatographies and reverse-phase HPLC. Their structures were established by spectroscopic methods, including UV, SI-MS and NMR. The structures of salfredins A4 and B11 were confirmed by X-ray crystallographic analysis.

Characterization of a 14q+ marker chromosome in philadelphia chromosome positive acute lymphoblastic leukemia by DNA analysis and fluorescence in situ hybridization

We report a case of precursor-B acute lymphoblastic leukemia (ALL) with the Philadelphia chromosome (Ph) and a 14q+ chromosome whose additional material was a part of the long arm of der(9)t(9;22). A minor population carrying the standard Ph translocation without the 14q+ was also observed at the first presentation. The translocation of the BCR gene from chromosome 22 to the subtelomeric region of the 14q+ was confirmed by fluorescence in situ hybridization (FISH) using a yeast artificial chromosome (YAC) clone containing the BCR gene. The breakpoint of chromosome 14 could not be determined exactly but probably was at 14q24 or 14q32 by conventional chromosome analysis. Nevertheless, FISH using a YAC clone containing the human immunoglobulin heavy chain (IgH) gene locus, Southern blot, and pulsed-field gel electrophoresis (PFGE) analyses with IgJH probe, and loss of heterozygosity analysis at the alpha 1-antitrypsin (AT) gene locus showed lack of involvement of the IgH gene in the 14q+ and more centromeric breakage than the alpha 1-AT locus at 14q32.1. Thus, the formation of the 14q+ seemed to be a secondary genetic event after the Ph translocation and presumably played a minor role in the pathogenesis of B-cell malignancy in this case.

Hepatocyte growth factor stimulates liver regeneration and elevates blood protein level in normal and partially hepatectomized rats

The effects of recombinant human hepatocyte growth factor (HGF) on liver growth and function of normal and partially hepatectomized rats have been examined. HGF was continuously administered into the jugular vein because it was rapidly eliminated from the plasma (t1/2 alpha; approximately 4.5 min) and degraded. In normal rats, the labeling index of hepatocytes was increased about 6 times by the administration of HGF. HGF also decreased the prothrombin time and increased the hepaplastin and serum albumin content. In 70%-hepatectomized rats, HGF stimulated liver regeneration and increased the level of blood proteins such as hepaplastin in a dose-dependent manner. The stimulation of serum protein level seemed to result from not only the increase of hepatic cell number but also the direct effect of HGF on the protein production in hepatocytes, because HGF rapidly enhanced the protein synthesis prior to the increase of cell number and increased the mRNA content of albumin in the liver in vivo. In addition, a combination of heparin with HGF further accelerated the effects of HGF described above, possibly due to the decrease of HGF clearance. These findings suggest that HGF accelerates both the hepatic regeneration and function in vivo, and that rhHGF is clinically expected to be a potent therapeutic agent in hepatectomy and liver injury.

Hemizygous expression of the wild-type p53 allele may confer a selective growth advantage before complete inactivation of the p53 gene in the progression of chronic myelogenous leukaemia

We analysed the expression of the p53 gene in various clinical phases of chronic myelogenous leukaemia (CML) by quantitative reverse transcriptase (RT) polymerase chain reaction (PCR). Hemizygous expression of the wild-type p53 allele was observed in two samples showing the loss of one p53 allele, and affected p53 expression was associated with p53 allelic loss rather than the clinical phase of CML. In four patients with CML showing p53 inactivation, we performed a detailed sequential analysis of p53 allelic loss, p53 mutation and expression from the onset of the disease to the patients' death. Consequently, we demonstrated that the loss of a wild-type p53 allele preceded mutation of the remaining allele, and that cells hemizygous for the wild-type p53 allele dominated those with both wild-type alleles, then were replaced by cells with complete p53 inactivation. These observations indicate that not only complete p53 inactivation but also hemizygous expression of the wild-type p53 allele may confer a selective growth advantage, and that the former is implicated in a more malignant phase than the latter. Alternatively, the inactivation of another undefined anti-oncogene on chromosome 17p may allow selective growth before the p53 mutation occurs.

TP53 mutations emerge at early phase of myelodysplastic syndrome and are associated with complex chromosomal abnormalities

We examined TP53 mutation in 57 patients with myelodysplastic syndrome (MDS) at either the MDS phase or at the terminal leukemic phase using polymerase chain reaction-mediated single-strand conformation polymorphism (PCR-SSCP) analysis. TP53 mutations within exons 5 through 8 were found in seven patients. All these mutations were detected at the presentation of MDS whether these patients showed leukemic transformation or not. TP53 mutations were frequently found in patients with loss of the short arm of chromosome 17 (17p-) (three of seven patients with 17p-, 43%) and complex karyotypic abnormalities (five of 14, 38%). Among the seven patients with the TP53 mutation, four patients progressed to acute leukemia within 7 months from the diagnosis of MDS, and the remaining three died within 7 months without leukemic transformation. These findings suggest that mutations of the TP53 can be implicated in leukemic transformation and a poor prognosis in MDS.

Neurofibromatosis 1 gene (NF1) mutation is a rare genetic event in myelodysplastic syndrome regardless of the disease progression

Neurofibromatosis 1 gene (NF1) is a tumor suppressor gene and the product of which down-regulates Nras protein by its GTPase activating protein-related domain (NF1-GRD). Although the incidence of NF1 mutation was reported to be rare in the chronic phase of myelodysplastic syndrome (MDS), there have been no previous reports on its configuration in patients showing the disease progression. We examined NF1 in 50 patients with MDS including 9 who had progressed to more advanced stages and 16 to acute leukemia. Six patients had an Nras mutation. We carried out allele specific restriction analysis (ASRA) to detect a mutation at the first nucleotide A of codon 1423 (AAG), a mutational hot spot. We also employed a polymerase chain reaction mediated single strand conformation polymorphism (PCR-SSCP) method to confirm the result of ASRA and to detect a point mutation in other sequences of FLR exon. In consequence, ASRA disclosed wild type configuration and PCR-SSCP showed no aberrant band in any sample examined whether the samples harboured an Nras mutation or not. We conclude that NF1 mutation does not play a crucial role in the development and the progression of MDS.

Carcinosarcomas of the esophagus

Two cases of carcinosarcoma of the esophagus are reported. Both were polypoid tumors occurring in the middle of the intrathoracic esophagus. The tumors were predominantly composed of spindle-shaped sarcoma cells with some squamous cell carcinomas (SCC). One tumor showed many bizarre giant cells with filamentous materials in the cytoplasm. Microscopical examination of both tumors revealed transition from SCC to sarcoma cells. Immunohistochemically, the spindle-shaped sarcoma cells in both tumors displayed a strongly positive immunoreaction to alpha-smooth muscle actin, as did the bizarre giant cells of one tumor to sarcomeric actin. SCC and a few spindle-shaped sarcoma cells near the SCC showed a positive immunoreaction to cytokeratin. Electron microscopy revealed that the spindle-shaped cells had many myofilaments with dense bodies and that the bizarre giant cells had sarcomere structures with Z-bands in their cytoplasm. These findings indicate that both tumors were carcinosarcomas of SCC and myogenic sarcoma. We considered that sarcoma cells might originate in SCC, representing its metaplastic differentiation, or that both SCC and sarcoma might originate in a pluripotent stem cell.

[Cisplatin, 5-fluorouracil and leucovorin combination chemotherapy-added radiation therapy for advanced esophageal cancer--a case report]

Cisplatin, 5-fluorouracil and leucovorin combination chemotherapy added radiation therapy was performed for the treatment of 62-year-old male patient with advanced esophageal cancer who had liver cirrlosis. After the treatment, esophageal lesion disappeared. Only minimal side effect occurred during the treatment. Biochemical modulation chemotherapy combined with radiation therapy is useful for advanced esophageal cancer.

Long-term follow-up of patients with a history of near fatal episodes; can inhaled corticosteroids reduce the risk of death from asthma?

We retrospectively studied the use of inhaled corticosteroids in patients who experienced near fatal episodes (NFE) to determine whether such therapy reduces the risk of death. Forty-eight patients who had near fatal episodes of asthma between January 1981 and December 1989 were divided into two groups. Group A comprised 19 patients who received beclomethasone dipropionate (BDP) daily (mean dose of BDP:687 micrograms/day: 200-2,000) following NFE, and Group B, 28 patients who did not take BDP or who took less than 6 mg BDP/month. During the follow-up period (Group A:82.9 months, Group B:66.2 months), no patients in Group A died, but eight deaths occurred in Group B (mean period between near fatal episode and death was 31.5 months: 12-66). These results suggest that the regular use of inhaled corticosteroids, even at low doses, may reduce the risk of death in patients who experience NFE.

Cavernous sinus invasion by pituitary adenomas--relationship between magnetic resonance imaging findings and histologically verified dural invasion

The relationship between magnetic resonance (MR) imaging findings and histologically verified invasion of the cavernous sinus by tumor cells was studied in 26 patients treated surgically for pituitary adenoma. Dural invasion of the sellar floor by tumor cells was found in 10 cases (38%). All patients were classified according to MR imaging findings into three types. Type I showed a gadolinium-enhanced stripe medial to the carotid artery (5 patients), none of which showed dural invasion. Type II showed no enhanced stripe (17 patients), six of which showed dural invasion. Within this type, tumor size and dural invasion showed no correlation. Type III showed displacement or encasement of the carotid artery by the tumor with or without extracranial extension (4 patients), all of which showed massive infiltration of the tumor cells into the dura mater. This study shows that preoperative MR imaging can provide information for assessment of invasion into the cavernous sinus in patients with pituitary adenoma.

[Double uterus and double vagina with unilateral imperforate vagina associated with ipsilateral renal agenesis: an infant case report]

Duplicated uterus associated with unilateral imperforate vagina and ipsilateral renal agenesis is a very rare anomaly. We report a case of a 10-month-old female infant presenting with pus discharge from vagina, and discussed the embryologic and clinical features relevant to this interesting disease complex with a review of the past literature. Echographic and CT examinations demonstrated a right-sided cystic pelvic mass. IVP revealed a left slight hydronephrosis and non-visualizing right kidney. No right ureteral orifice was found at cystoscopy. Under anesthesia the mass and pus was aspirated. Under the diagnosis of Gartner's cystic duct and a right renal agenesis or dysplasia with or without ectopic ureter, we subsequently performed laparotomy. Surgical exploration revealed a duplicated uterus with a normal ovary, and the mass was an imperforate right-sided vagina which communicated through the uterus. The diagnosis was changed to a double uterus with right-sided imperforate vagina, then the vaginal septum was excised. The post-operative course was uneventful, and pus discharge and the left hydronephrosis have disappeared.

[Aneurysm surgery using temporary occlusion under SEP monitoring]

Premature rupture of a cerebral aneurysm during operation is a serious hazard. Temporary occlusion of intracranial arteries has emerged as a valuable technical adjunct in the management of intracranial aneurysms. Twenty-five patients (from a group of 43 consecutive aneurysm patients treated during a 13-month period) underwent elective temporary arterial occlusion under somatosensory evoked potential (SEP) monitoring. Median nerve SEPs were used during 19 ICA and MCA aneurysm operations, while posterior tibial SEPs only were used in 7 patients with aneurysm of the ACA. Amplitude of the N20 or P40 was evaluated. A decrease in amplitude more than 50% when compared to baseline value was defined as a significant SEP change. In 11 patients of the 25 cases, SEP changes were observed. Temporary occlusion was applied to the proximal portion of the internal carotid artery 10 times, to the M1 portion of the middle cerebral artery 5 times, to the M1-M2 complex 5 times, to the A1 portion of the anterior cerebral artery 9 times, and to the A2 - A3 once. Of the 26 clipping (25 patients), 12 had SEP alterations, 14 had no SEP changes. Temporary occlusion was released within 3 minutes after disappearance of N20 (or P40) in all the patients with SEP changes except one. Nine of these 11 patients showed complete recovery of SEP and two showed partial recovery. Patients with partial recovery of SEP were associated with postoperative new neurological deficit, which was transient in one of them. There was a correlation between changes in SEP and post operative outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

The fate of the adult exstrophy patient

Between 1968 and 1993, 101 patients with bladder exstrophy or incontinent epispadias underwent surgery at our hospital. The standard procedure was ureterosigmoidostomy and additional genital reconstruction. Of the 56 patients who have reached adulthood 45 could be interviewed regarding social integration, sexuality and fertility. All patients have a functioning urinary diversion. Of the 45 patients questioned 41 have completed vocational training or are currently in training, 3 are unemployed and 1 lives at a therapeutic center. Among the patients 29 are married or have a steady partner. All women engage in sexual intercourse and 2 have delivered 3 children by cesarean section. All men achieve erection. Of the 28 men who underwent reconstruction of the external genitalia 11 have a penile deviation, which is distressing in only 2. Only 3 of the men are dissatisfied with the cosmetic result and 33% had epididymitis, necessitating 2 orchiectomies and 3 vasectomies. No patient with reconstruction of the external genitalia can ejaculate normally or has fathered children, whereas all 5 who did not undergo genital reconstruction had normal ejaculation and 2 have fathered children. Male patients with genital reconstruction and closure of the urethra have a high risk of infertility. Our patients demonstrate that the cosmetic results after genital reconstruction are satisfactory. However, in male patients, surgery is performed at the expense of fertility. Because this corrective procedure is usually performed during childhood, the parents must be informed of these consequences before surgical correction.

Determination of a new H(+)-K+ ATPase inhibitor (E3810) and its four metabolites in human plasma by high-performance liquid chromatography

A method for the simultaneous determination of E3810, 2-[(4-(3-methoxypropoxy)-3-methyl pyridine-2-yl)methyl sulfinyl]-1H-benzimidazole sodium salt and its four metabolites, demethylated-E3810 (DM), demethylated thioether-E3810 (DMTE), sulfone-E3810 (S), and thioether-E3810 (TE), in human plasma by high-performance liquid chromatography (HPLC) with UV absorbance detection has been established. The correlation coefficient for all the standard curves was 0.998 or greater. The quantitation limit was 5 ng/ml for E3810 and 20 ng/ml for each of its four metabolites. The recovery of E3810 and its four metabolites from human plasma was high, being greater than 80% when 100 ng of each substance was added per tube, except for DM (74.1%). The stability of E3810 and its four metabolites was evaluated and the following results were obtained: (1) when samples were centrifuged within 20 min after collection, there was no loss of E3810 or its metabolites; (2) when 100 microliters of a 1% aqueous solution of diethylamine was added within 20 min after plasma isolation, there was no loss of E3810 or its metabolites; and (3) there were no stability problems during storage for a period of 10 months at -20 degrees C.

Enantiomeric separation of drugs by affinity electrokinetic chromatography using dextran sulfate

Dextran sulfate (sodium salt), which is a mixture of a linear alpha-(1,6)-linked D-glucose polymer having a sulfate group in the molecule, has been employed as a chiral selector in affinity electrokinetic chromatography (EKC) for the separation of enantiomers of drugs. Enantiomers of trimetoquinol hydrochloride and its positional isomer have been successfully separated by the method using a 3-5% dextran sulfate buffer solution of pH 5.5 within 20 min. The effects of buffer pH, concentration of dextran sulfate, and additives (such as an organic solvent, urea and a surfactant) on the enantioselectivity were investigated. The choice of pH and the concentration of dextran sulfate has been important for the improvement in selectivity.

[Scrotal calcification associated with hydrocele testis in a child: a case report]

Scrotal calcification is a rare complication of childhood hydrocele testis. Herein, a 12-year-old boy who suffered from left hydrocele testis with intrascrotal calcification is reported. The boy had experienced scrotal pain about 6 months prior to the first visit to our hospital, and gradually noted scrotal swelling. Physical examination revealed left scrotal enlargement with transillumination. Sonographic examination revealed a left hydrocele testis, and a 1.5 cm discrete focus of calcification was found immediate cranio-lateral to the left testis, contour, size and consistency of which were palpated normally. In left hydrocelectomy, no appendix epididymidis was found. A smooth, white, spherical, firm body connecting to the head of the epididymidis was removed. A microscopic examination revealed multiple layers of collagenous tissue with the necrotic tissue in the core. We concluded that this case presented with hydrocele testis secondary to a growing calcification reacting to the infarction due to the repeated torsion of the appendix epididymidis.

Pharmacokinetic properties of E3810, a new proton pump inhibitor, in healthy male volunteers

E3810 is a new H+,K(+)-ATPase inhibitor with a substituted benzimidazole, which is under clinical investigation for peptic ulcer treatment in Japan and the USA. Three separate studies were conducted to evaluate the safety and to establish the pharmacokinetic profile of E3810 after oral administration to healthy male subjects. E3810 was administered as: single oral doses (1, 3, 10, 20, 40 and 80 mg) in fasting conditions, a single oral dose (20 mg) after a meal and repeated oral doses (20 and 40 mg) once daily for 7 days. The concentrations of E3810 and its metabolites in plasma and urine were determined by HPLC methods with UV detection. E3810 was generally well tolerated by all subjects. In the single-dose study, Cmax and AUC increased with increasing doses in the dose range examined. The mean plasma half-life was about 1.0 hour and was dose-independent. The apparent oral clearance of E3810 ranged from 4.37 to 8.40 ml/min/kg. No significant deviation from linear pharmacokinetics was observed. Approximately, 30% of a dose was excreted into the urine as thioether carboxylic acid-E3810 and its glucuronide. The mean serum protein binding was 96.3%. No effect of food intake on the Cmax and AUC was observed while tmax after a meal was 1.7 hours longer than that in the fasting conditions. No appreciable change in drug pharmacokinetics was observed during repeated oral dosing of E3810.

N-ras mutation and karyotypic evolution are closely associated with leukemic transformation in myelodysplastic syndrome

We performed a longitudinal analysis of the karyotypes and N-ras gene configuration of bone marrow cells in 35 patients with myelodysplastic syndrome (MDS). Karyotypic evolution was found in eight patients, and was associated with disease progression, including leukemic transformation, in all the patients. We identified N-ras mutations in six patients, using a polymerase chain reaction (PCR) technique, in which oligonucleotide primers were constructed with induced mismatches, followed by endonuclease digestion. Direct sequencing confirmed single base substitutions at codon 12 in two patients and at codon 13 in four. The incidence of N-ras gene mutations was significantly higher in the karyotypically evolved group (five of eight patients) than in the stable group (one of 27 patients). All of five patients harboring both karyotypic evolution and an N-ras mutation showed concomitant disease progression to overt leukemia or refractory anemia with excess of blasts in transformation (RAEB-T). Two of four patients with either karyotypic evolution or N-ras mutation and six of 26 patients without any of these alterations also progressed to overt leukemia. Our results indicate that the accumulation of these genetic alterations is closely associated with leukemic transformation of MDS, although other genetic alterations may also play a key role in the remaining patients.

Multiple aberrant splicing of the p53 transcript without genomic mutations around exon-intron junctions in a case of chronic myelogenous leukaemia in blast crisis: a possible novel mechanism of p53 inactivation

We found three truncated p53 transcripts in a patient with chronic myelogenous leukaemia in blast crisis carrying chromosome 17 abnormalities. Sequencing of these transcripts revealed complete absence of the entire exons 7, 8 and 9 in one, exons 8 and 9 in another, and exon 10 in the other. Sequencing analysis of genomic DNA, however, revealed no mutation in exons 6-10 and their flanking introns. These results suggest that the aberrant p53 transcripts in this case might not result from splicing mutations but from an unknown affected splicing process.