[Experimental studies of the protective effect of deferoxamine mesilate on cisplatin induced toxicity]

Cisplatin (CDDP) is an antitumor agent against several types of neoplasms. It has, however, various side effects such as nephrotoxicity and ototoxicity. Several efforts have been made to prevent these toxic side effects. On the other hand, deferoxiamine mesilate (DFO), an iron-chelating agent, has been used for iron-overloaded patients. Since the 1980s, many authors have reported DFO-associated hearing impairment. Some experimental data suggest that DFO itself was responsible for ototoxicity. In addition, it has also been recognized that DFO can act as a free radical scavenger. Experimental trials using DFO are also expected to prevent CDDP-induced toxicity because its generation mechanism is thought to be associated with free radical formation. The present study was planned to investigate whether DFO, which might be an ototoxic agent, had a protective effect against various CDDP-induced toxicities including ototoxicity. Fisher rats were used in this study and were divided into four groups: 1) Group I, a vehicle control, 2) Group II, animals receiving 100 mg of DFO per kg, 3) Group III, animals administered 0.9 mg of CDDP per kg alone and 4) Group IV, animals receiving 100 mg of DFO per kg 60 min before 0.9 mg of CDDP per kg for 10 days. First, the protective effect of DFO against CDDP-induced ototoxicity was studied. The auditory threshold was determined by using the compound action potential (CAP) from the round window membrane. CAPs were recorded on the 5th day after completion of drug administration. Then CAPs recording, cochlear sensory epithelia were observed over all the turns of the cochlea by scanning electron microscopy. There were no significant differences in CAP thresholds between Group I and IV, though the thresholds in Group III were significantly higher at 16 kHz and 20 kHz than those in Group IV. The rate of missing outer hair cells in Group IV was significantly lower than that in Group III. The results clearly demonstrated that DFO had a protective effect against CDDP-induced ototoxicity. Second, the protective effect of DFO against CDDP-induced nephrotoxicity was studied. Renal function was evaluated by measuring blood urea nitrogen (BUN) and serum creatinine (Cr) levels. Both BUN and Cr levels in Group IV were significantly lower than those in Group III. The data suggested that DFO preadministration prevented CDDP-induced nephrotoxicity. Third, the influence of DFO on the antitumor activity of CDDP was investigated in rats inoculated with squamous cell carcinoma cells (SCC-131) subcutaneously. The influence of drugs was determined by measuring the tumor growth rate. There was no difference in the tumor growth rate between Group III and IV. The result revealed that DFO had no influence on CDDP antitumor activity. In conclusion, the above results demonstrating that DFO preadministration can prevent both CDDP-induced ototoxicity and nephrotoxicity without attenuation of CDDP antitumor activity, suggest the usefulness of CDDP antitumor chemotherapy.

Appearance of a different clone of Epstein-Barr virus genome in recurrent tumor of pyothorax-associated lymphoma (PAL) and a mini-review of PAL

A case of pyothorax-associated lymphoma (PAL) is reported. A 76-year-old Japanese man developed a lymphoma in the pleural cavity after 46 years duration of pyothorax due to pulmonary tuberculosis. The histologic diagnosis of biopsy specimen was diffuse large cell lymphoma of B cell type. The lymphoma cells contained the monoclonal Epstein-Barr virus (EBV) determined by the analysis of terminal repeat of EBV genome and expressed EBV nuclear antigen 2 and latent membrane protein 1 (LMP1). He received antineoplastic chemotherapy and was induced to complete remission (CR). After 19 months of CR, the lymphoma developed again in the thoracic wall. Histopathology and immunohistochemical phenotypes of recurrent tumor were almost the same as those of the primary tumor with the exception of a little more frequent expression of LMP1. The EBV genome in lymphoma cells was monoclonal, however, the clone was different from that of the primary tumor. After antineoplastic chemotherapy, minor EBV-positive clones in primary lymphoma might survive and develop into recurrent tumor. These results suggest that the PAL starts as poly- or oligoclonal proliferation of B lineage cells. This poly- or oligoclonality of PAL at the initial stage may suggest underlying immunosuppressive conditions in the development of PAL.

[An experimental study of ototoxicity induced by deferoxamine mesilate]

We investigated the possibility of ototoxicity induced by deferoxamine mesilate (DFO). DFO was administered to guinea pigs intraperitoneally at 200 or 400 mg/kg body weight/day, 6 days/week for 5 weeks, or 600 mg/kg body weight/day, 6 days/week for 4 weeks. Physiological saline instead of DFO was given to animals as a control. After the course of administration was completed, we measured the threshold of the compound action potential (CAP) and the endocochlear potential (EP). We also examined the cochlear histology by scanning electron microscopy. The CAP threshold of animals treated with 200 or 400 mg of DFO per kg was not elevated. In the animals treated with 600 mg/kg , however, the CAP threshold was clearly elevated when compared with that of control animals. The EP values of animals treated with 200 or 400 mg of DFO per kg were comparable to those of control animals. In some animals treated with 600 mg of DFO per kg, however, the EP values were decreased. Histological examination revealed that the outer hair cells of the cochlea were missing. DFO presumably acts on hair cells, resulting in elevation of the CAP threshold. We concluded that hair cell damage is one of the contributing factors to CAP threshold elevation.

Hepatitis C viral genome in a subset of primary hepatic lymphomas

Hepatitis B virus (HBV) and hepatitis C virus (HCV) are not only hepatotropic but possibly hematotropic. Recent studies showed the presence of HBV in lymphoma cells of extrahepatic origin. In the current study, we examined the presence of HBV DNA and HCV RNA in the tumor tissues of nine patients with primary hepatic lymphoma (PHL). Immunohistochemical study using polyclonal anti-HCV antibody was possible in four cases. The age of the patients ranged from 45 to 78 years (median, 58 yr), with a male-to-female ratio of 2:1. A history of chronic hepatitis was found in three patients and of cirrhosis in one. Histologically, all of the cases were non-Hodgkin's lymphoma of B-cell phenotype, with a diffuse large cell type being the most common. Polymerase chain reaction using both the S and X region primers failed to detect HBV DNA in the lymphoma tissues. The HCV genome was detected by in situ hybridization in the tumor cells but not in the surrounding hepatocytes in the one case of cirrhosis, which probably resulted from a blood transfusion more than 20 years previous; immunohistochemical analysis revealed positive staining for anti-HCV antibody in the cytoplasm of lymphoma cells in this case. In two cases, positive signals were found only in the hepatocytes surrounding the lymphoma. This is the first report showing the presence of the HCV genome in the lymphoma cells of PHL. HCV could be involved in development of PHL directly or via exogenic antigenic stimulus from HCV-infected hepatocytes.

Delayed onset of hemolytic anemia in CBA-Pk-1slc/Pk-1slc mice with a point mutation of the gene encoding red blood cell type pyruvate kinase

The Pk-1slc gene encodes a mutant red blood cell (RBC) type pyruvate kinase (PK), and adult CBA-Pk-1slc/Pk-1slc mice show a severe nonspherocytic hemolytic anemia. However, the number of RBCs and the proportion of reticulocytes were comparable between neonatal CBA-Pk-1slc/Pk-1slc mice and control -+/+ mice. Since the age-dependent increase of RBCs was much greater in CBA-+/+ mice than in CBA-Pk-1slc/Pk-1slc mice, significant anemia was observed in the latter mice on day 14 after birth. The increase of RBCs in CBA-+/+ mice was due to the prolongation of their survival time. The half life of RBCs increased in CBA-+/+ mice with ages, but it decreased in CBA-Pk-1slc/Pk-1slc mice. The relatively longer half life of RBCs in neonatal CBA-Pk-1slc/Pk-1slc mice appeared to be due to the delayed switching from M2-type PK that are expressed by undifferentiated erythroid precursor cells to RBC-type PK that are expressed by mature RBCs.

Expression and enzymatic characterization of human glucose phosphate isomerase (GPI) variants accounting for GPI deficiency

To elucidate the structure-function relationships in glucose phosphate isomerase (GPI), we established an expression system for human GPI as a fusion protein with glutathione S-transferase (GST) in E. coli. The GST-GPI fusion protein showed affinities for the substrates glucose 6-phosphate (G6P) and fructose 6-phosphate (F6P) similar to those of the native enzyme purified from human red blood cells (RBC). We expressed GPI cDNAs with four distinct disease-causing mutations and examined their enzymatic characteristics. Although each mutation caused reduced thermal stability, an amino acid substitution Thr-5-->Ile (T5I) exhibited marked thermal instability, suggesting that the amino-terminal of GPI is important for enzymatic stability. Thr-224 seemed not to be an essential residue, since the amino acid substitution Thr-224-->Met (T224M) showed normal substrate affinity in spite of a slight decrease in both specific activity and thermostability. Gln-343 and Asp-539 have been shown to be in close proximity to the putative catalytic sites, and the present study showed that both Gln-343-->Arg (Q343R) and Asp-539-->Asn (D539N) caused impaired substrate affinity; Q343R showed high Km for both G6P and F6P, whereas D539N showed significantly decreased affinity only for F6P. These results suggest that not only reduced enzymatic stability but also impaired kinetics may disturb RBC metabolism of the GPI variants associated with hereditary hemolytic anemia.

Large-vessel arteritis associated with chronic active Epstein-Barr virus infection

This report describes an autopsy case of large-vessel arteritis associated with chronic active Epstein-Barr virus (EBV) infection in a 10-year-old Japanese girl. All of the 3 main coronary arteries, bilateral common carotid and subclavian arteries, abdominal aorta and its major branches, and bilateral common iliac arteries were involved, and all showed aneurysmal dilation of the lumens. Histopathologic examination revealed mesoarteritis characterized by moth-eaten-appearing destruction of the medial elastic laminae, with T lymphocyte infiltration around the vasa vasorum and severe intimal thickening. The EBV DNA genome was detected in the diseased aortic tissue by polymerase chain reaction, and in the infiltrating lymphocytes by in situ hybridization. The clinical symptoms and histopathologic manifestations of the arterial lesions in this patient were obviously different from those of Kawasaki disease and Takayasu arteritis, and the arteritis was considered to be associated with the EBV infection.

Viability and function of human sperm in electrolyte-free cold preservation

OBJECTIVE

To assess the viability and function of human sperm in electrolyte-free cold preservation.

DESIGN

Prospective comparative study.

SETTING

Andrology laboratory of our hospital.

PATIENT(S)

Ten semen samples obtained from patients attending our infertility clinic.

INTERVENTION(S)

Ejaculated sperm were washed using the electrolyte-free Percoll gradient and were then preserved in 0.33 M glucose solution, 0.16 M NaCl solution, 0.16 M KCl solution at 4 degrees C for 4 weeks. As a control, TEST (TES and Tris) yolk buffer (TYB) was added to the ejaculated semen and preserved at 4 degrees C.

MAIN OUTCOME MEASURE(S)

Sperm tail morphology, motility, viability (eosin-Y stain), and the concentration of adenosine triphosphate (ATP) were analyzed.

RESULT(S)

The number of sperm with normal tail form and the motility of sperm preserved in glucose solution (electrolyte-free cold preservation) were significantly (P < 0.01) higher for 4 weeks than those of sperm preserved in the other three media. The sperm viability in glucose solution was 75.5%, 65.4%, and 51.3%, after 1, 2, and 4 weeks, respectively. The ATP concentration after 1, 2, and 4 weeks remained 64.2%, 53.0%, and 4.3% of the prestorage value, respectively, in the sperm stored in glucose solution.

CONCLUSION(S)

The morphology, motility, viability, and ATP concentration of sperm in electrolyte-free cold preservation were substantially better than those in NaCl solution, KCl solution, or TYB for 2 weeks.

Thoracoscopic treatment of esophagobronchial fistula with esophageal diverticulum

Thoracoscopic fistulectomy and diverticulectomy for esophagobronchial fistula with esophageal diverticulum were performed on a 49-year-old-woman. The neck of the diverticulum and the fistula were divided with endo-stapling technique. Intraoperative esophagoscopy was found to be useful for the definite localization and complete excision of the fistula and the diverticulum and the avoidance of stenosis of the esophagus. To avoid the recurrence of fistula, a pedicle of viable mediastinal pleura was interposed between esophageal and bronchial closures. Postoperative course was uneventful, and the complete relief of symptom was experienced for a period of 10 months after the operation. It is to be considered that the present thoracoscopic procedure with intraoperative esophagoscopy can be used as a standard operative procedure for esophagobronchial fistula with esophageal diverticulum.

Detection and analyses of ascorbyl radical in cerebrospinal fluid and serum of acute lymphoblastic leukemia

We have detected and analyzed a free radical in human cerebrospinal fluid (CSF) of acute lymphoblastic leukemia (ALL) for the first time using electron paramagnetic resonance (EPR) at ambient temperature. We have also introduced an alternative capillary method to measure the radical. EPR spectra of the radical show a characteristic doublet with hyperfine coupling value of 1.8 G and g = 2.005. Based on EPR measurements, computer simulation, and literature values, we have determined that the species is ascorbyl radical (AsR). The radical has been investigated in CSF samples from ALL patients having no therapy, undergoing chemotherapy, and following therapy. Determination of the ascorbyl radical concentrations in CSF and serum was attempted using known concentrations of a nitroxyl radical. In addition, comparison in CSF and serum for ALL has been made along with statistical analyses of the data obtained. We found that AsR in CSF and serum has a strong correlation in patients undergoing chemotherapy (n = 57, r = 0.57, P < 0.0001). Ascorbate in CSF and serum show good correlation in patients having therapy but not for patients after therapy.

Computed tomographic study of aged schizophrenic patients

The width of interhemispheric fissure, lateral ventricles and third ventricle were measured using cranial computed tomography (CT; linear method) in 45 elderly inpatients with chronic schizophrenia and in 28 age-matched control subjects. Twenty-three patients were men and 22 were women. In addition, Mini-Mental State Examination, Brief Psychiatric Rating Scale (BPRS) and a subclass of BPRS were undertaken in all patients. There is a significant enlargement of the maximum width of the interhemispheric fissure (in both male and female) and a significant enlargement of the ventricular system (more severe in men than in women) in aged schizophrenics, as seen with CT, compared with normal controls. These findings are consistent with previous studies of non-aged schizophrenic patients. Based upon the relation between the third ventricle enlargement and the positive and depressive symptoms in all patients. This result suggests that the advanced third ventricle enlargement may decrease these symptoms in aged schizophrenics.

[Clinical evaluation of a reagent for detection of DNA of Mycobacterium tuberculosis complex using the ligase chain reaction (LCR) method]

We evaluated the clinical efficacy of LCR MTB, a reagent developed by Abbott in the USA, in the full automatic ligase chain reaction (LCR) for detection of DNA of M. tuberculosis complex using a thermostable ligase. Using 458 samples isolated from patients with tuberculosis, LCR was compared with a smear method and with a culture method, and was also compared with two other methods of gene amplification, MTD and Amplicor, using 340 and 200 of the 458 samples, respectively. The LCR method detected M. tuberculosis in 49.8% (228/458) of the samples, and was superior to the smear method (31.9%, 146/458) and the culture method (39.1%, 179/458) in sensitivity. The LCR method was also superior to the MTD and Amplicor methods; sensitivity were 37.9% (129/340) for MTD vs. 47.6% (162/340) for LCR, and 56.5% (113/200) for Amplicor vs. 59.5% (119/200) for LCR. These favorable results and the convenience of the LCR method, which enables rapid detection of target genes with a high degree of sensitivity, strongly suggest that LCR MTB is useful as a reagent for detection of M. tuberculosis using nucleic acid amplification.

[Tuberous sclerosis associated with subependymal giant cell astrocytoma and renal angiomyolipoma: a case report]

We presented a case of tuberous sclerosis (TS) associated with subependymal giant cell astrocytoma (SEGC) and renal angiomyolipoma (RAML). A 19-year-old female, who had been diagnosed as TS since she was 3 months old, was admitted with complaints of headache, vomiting, and abdominal pain. At 10 years of age, a ventricular tumor was shown on CT, and at 16 years of age a ventricular peritoneal shunt was placed for obstructive hydrocephalus. On admission, an abdominal CT showed bilateral renal huge multicystic tumors with hemorrhage, which were diagnosed as RAMLs. CT and MRI showed an intraventricular tumor near the foramen of Monro, and this tumor was removed through a transcortical approach. The pathological diagnosis was SEGA. Large sized RAMLs were identified by CT. Although TS is often associated with additional tumors in the brain, heart, kidney, and other organs, the combination of SEGA and RAML is quite rare. If ventricular peritoneal shunt is placed in a TS patient, risk of shunt malfunction should be taken into account.

[The in vitro antifungal activities of fluconazole against pathogenic yeasts recently isolated from clinical specimens]

The emergence of Candida albicans resistance to azole antifungal agents have been reported in the U. S. and Europe. We examined the in vitro antifungal activities of fluconazole against clinical isolates collected by seven investigators in three years to examine if a tendency existed toward the development of azole-resistance among fungal isolates in Japan. The following results were obtained: 1. Sensitivities to fluconazole (FLCZ) were determined for yeast-like fungi, including 113 strains isolated in 1993, 149 strains isolated in 1994 and 205 strains isolated in 1995. No significant differences in sensitivities in the three years were detected. 2. Minimum inhibitory concentrations of FLCZ were 0.1-0.78 microgram/ml for C. albicans and 3.13-25 micrograms/ml for C. glabrata. Strains with 25 micrograms/ml of FLCZ's MIC were detected; two strains of C. krusei and one strain each of C. krusei, Trichospron beigelii and Hansenula anomala. No strains with higher than 50 micrograms/ml MIC of FLCZ were detected. 3. In vitro activities of FLCZ were compared between clinical strains isolated between 1993 and 1995 and clinical strains isolated before the marketing of FLCZ (up to December 1987) or clinical yeasts isolated between 1991 and 1992. No significant differences were observed, suggesting that no tendency existed toward azole resistance among fungal strains examined.

[Current status of clinical diagnosis and DNA test of von Hippel-Lindau disease in Japan]

An outline of the clinical diagnosis including the DNA testing in von Hippel-Lindau (VHL) disease is briefly explained. The current status of the diagnosis and treatment of VHL disease in Japan is also compared with those in European countries. According to the current experience in the world, DNA testing of VHL disease is regarded as one of the important references for the clinical diagnosis of this disease. We have to improve various points in the Japanese status of the clinical diagnosis, genetic counseling, treatment and follow-up in patients with VHL disease.

Frame shift mutation, exon skipping, and a two-codon deletion caused by splice site mutations account for pyruvate kinase deficiency

Three novel splice site mutations and two novel missense mutations were identified by molecular analysis of pyruvate kinase (PK) deficiency associated with hereditary nonspherocytic hemolytic anemia. A Nepalese PK variant, PK Kowloon, was found to have a homozygous transversion at the 5'-splice site of the seventh intervening sequence (IVS) of the L-type PK gene (Ivs7[+1]gt --> tt). Using a reverse transcription polymerase chain reaction (RT-PCR) assay, we showed that the R-type PK mRNA in the proband's reticulocytes included the seventh IVS between the seventh and eighth exon, introducing a stop codon 3 nucleotides downstream of the mutated site. Consequently, the translational product may lack 44% of the R-PK polypeptide. A transition at the last nucleotide of exon 9 (1269GCG --> GCA) was found in a Japanese PK variant, PK 'Kamata.' The mutation did not alter the amino acid sequence, but caused skipping of the ninth exonic sequence in the R-PK transcripts. As a result, the affected R-type PK lost 51 amino acid residues (373Met-423Ala del). A transversion at the splice acceptor site of the third IVS (Ivs 3[-2]ag --> tg) was identified in PK 'Aomori.' The mutation resulted in aberrant splicing at a cryptic splice site within exon 4, causing deletion of two codons in the aberrant R-PK transcript (95 Gly-96 Pro --> del). Both PK 'Kamata' and PK 'Aomori' had a missense mutation on the other allele, 1044AAG --> AAT (348Lys --> Asn) and 1075CGC --> TGC (359Arg --> Cys), respectively. Although both 348Lys and 359Arg were located in the sixth loop of A domain (beta/alpha)8 barrel, which has been shown to contain the substrate and cation binding sites, the degree of anemia was much more severe in PK 'Kamata' than PK 'Aomori,' possibly because the 51 amino acid deletion of PK 'Kamata' but the 2 amino-acid deletion of PK 'Aomori' may abolish PK catalytic activity.

Changes in corneal and lens autofluorescence and blood glucose levels in diabetics: parameters of blood glucose control

PURPOSE

We investigated corneal and lens autofluorescence in patients with proliferative diabetic retinopathy (PDR) to determine a correlation between the two parameters and blood glucose levels and HbA1c.

METHODS

Corneal and lens autofluorescence levels in 17 PDR patients and 8 healthy controls were measured with a fluorophotometer fitted with an anterior segment adapter. We measured the lower blood glucose level (BS1), corneal autofluorescence (CA1), and lens autofluorescence (LA1) simultaneously and the higher blood glucose level (BS2), CA2, and LA2 simultaneously on the same day. We defined parameter changes as: delta BS = BS2 - BS1, delta CA = CA2 - CA1, and delta LA = LA2 - LA1.

RESULTS

Corneal and lens autofluorescence significantly increased in the patients, compared with the controls (p < 0.001). Lens autofluorescence had a significant positive correlation with HbA1c (r = 0.656, p < 0.01) in the patients. delta CA (ngEq/ml) correlated significantly with delta BS (mg/dl) (r = 0.631, P < 0.01).

CONCLUSIONS

Results suggest that lens autofluorescence might represent the long-term control of diabetes, and corneal autofluorescence levels may represent short-term changes in the blood glucose level, because hyperglycemia accelerates with increasing corneal autofluorescence in PDR patients. Corneal and lens autofluorescence may be related to the breakdown of the blood-aqueous barrier.