Intervention of somatic mutational events in vivo by a germline defect at the adenine phosphoribosyltransferase locus

Both germline and somatic mutations are known to affect phenotypes of human cells in vivo. In previous studies, we cloned mutant peripheral blood T cells from germline heterozygous humans for adenine phosphoribosyltransferase (APRT) (EC 2.4.2.7) deficiency and found that approximately 1.3 x 10-4 peripheral T cells had undergone in vivo somatic mutations. Loss of heterozygosity (LOH) was the major cause of the mutations at the APRT locus since approximately 80% of the mutant T cell clones exhibited loss of normal alleles. In the present study, we identified three heterozygous individuals for APRT deficiency (representing two separate families), in whom none of the somatic mutant cells exhibited LOH at the APRT locus. The germline mutant APRT alleles of these heterozygotes from two unrelated families had the same gross DNA abnormalities detectable by Southern blotting. None of the germline mutant APRT alleles so far reported had such gross DNA abnormalities. The data suggest that the germline mutation unique to these heterozygous individuals is associated with the abrogation of LOH in somatic cells. The absence of LOH at a different locus has already been reported in vitro in an established cell line but the present study describes the first such event in vivo in human individuals.

Effect of sex hormones on the tissue localization of nuclear estrogen receptor positively stained cells in the seminal vesicle of immature castrated rats

We studied the changes in the tissue localization of nuclear estrogen receptor (ER) positively stained cells in the seminal vesicle of immature castrated rats under various environmental conditions of sex hormones by immunohistochemical methods. In castrated rats of 6 weeks of age, the percentage of nuclear ER positively stained cells showed remarkable increase in the periglandular stroma region, but not in the epithelium and the peripheral stroma region. Estrogen administration to castrated rats dramatically increased the percentage of nuclear ER positively stained cells in both the epithelium and the peripheral stroma region, whereas cessation of estrogen treatment caused a significant percentile decrease. These results suggest that the nuclear ER expression in both the epithelial cells and the peripheral stromal cells seems to respond to estrogen. The concomitant treatment of estradiol-17 beta (E2) with 5 alpha-dihydrotestosterone (DHT) completely inhibited these E2 mediated ER expression in the epithelium and the stroma. This result suggests that ER works only when E2 is given in the absence of DHT in the seminal vesicle of immature castrated rats.

[A case report of renal cell carcinoma with bilateral adrenal metastases]

A 52-year-old man consulted our hospital with a right abdominal mass. Imaging diagnosis revealed a 10.5-cm right renal tumor and bilateral adrenal masses (7 cm on the left side and 2.5 cm on the right). A radical nephrectomy and bilateral adrenalectomy demonstrated renal cell carcinoma with metastases to bilateral adrenal glands. Despite prophylactic treatment with interferon-alpha, a swollen left cervical lymph node and a left renal mass, which seemed to be metastatic lesions, developed respectively 6 and 33 months postoperative. He is alive with disease at 40 months.

Epidemiologic survey of lower urinary tract symptoms in Asia and Australia using the international prostate symptom score

BACKGROUND

The prevalence of lower urinary tract symptoms was determined by survey as an initial step in estimating the significance of benign prostatic hyperplasia (BPH) in Asia and Australia.

METHODS

The symptom index (0 to 35) and quality-of-life (QOL) index (0 to 6) of the international prostate symptom score were measured in 7588 men in 9 Asian countries and 146 men in Australia.

RESULTS

The percentages of Asian men considered to be symptomatic (symptom index > or = 8) were 18%, 29%, 40%, and 56% in the age groups of 40 to 49, 50 to 59, 60 to 69, and 70 to 79 years, respectively. For Australian men, these figures were 36%, 33%, and 37% in the 50 to 59, 60 to 69, and 70 to 79 year age groups, respectively.

CONCLUSIONS

Our estimates indicate that the prevalences of symptomatic men in Asia and Australia are similar to or greater than those in Europe and America, and suggest BPH is similarly common in these areas.

Generation and molecular characterisation of monoclonal IgG4 rheumatoid factor from a patient with rheumatoid arthritis

OBJECTIVE

To characterise IgG4 rheumatoid factor (RF) at the molecular level from a patient with rheumatoid arthritis.

METHODS

B cells were cloned from the peripheral blood of a patient with rheumatoid arthritis, using EB virus transformation. The supernatants of the clones were screened for IgG RF activity by ELISA. Nucleotide sequences of the expressed immunoglobulin heavy and light chain genes of one IgG RF producing clone were determined by direct sequencing of the products of a polymerase chain reaction.

RESULTS

One clone producing monospecific IgG4 RF was obtained. Sequence analysis of the heavy and light chain genes suggested the accumulation of somatic mutations resulting in amino acid replacement in complementarity determining regions.

CONCLUSIONS

The results may suggest an antigen driven response in the generation of IgG4 RF in rheumatoid arthritis disease processes.

An asymptomatic germline missense base substitution in the hypoxanthine phosphoribosyltransferase (HPRT) gene that reduces the amount of enzyme in humans

A 40-year-old normouricemic (5.5 mg/dl) male showed 46% hemolysate and 37% lymphoblast hypoxanthine phosphoribosyltransferase (HPRT) activities but was otherwise completely free of symptoms. His genomic DNA and cDNA had a missense base substitution (CAT-to-CGT in codon 60) leading to the amino-acid substitution His-to-Arg. Western blot analysis revealed that the amount of HPRT protein in lymphoblasts from this individual was 25%-50% of normal cells, suggesting that the decrease in the amount of enzyme protein was responsible for the partial deficiency. This provides the first clear evidence that a genomic missense mutation at the HPRT locus leads to a decrease in the amount of the enzyme protein but that otherwise it has no evident adverse effects in the hemizygote (asymptomatic mutation).

[Effects of Gosha-Jinki-Gan on the function of the urinary bladder in anesthetized dogs]

Gosha-Jinki-Gan is clinically used for the treatment of pollakiuria in patients with benign prostatic hyperplasia. The effect of Gosha-Jinki-Gan on the function of the urinary bladder in anesthetized dogs was examined. Gosha-Jinki-Gan (100 mg/kg) inhibited the rhythmic bladder contractions (RBC). However, the frequency of RBC increased resembling the effect of atropine (0.1 mg/body), and the amplitude decreased. On the cystometrogram, Gosha-Jinki-Gan caused an increase in maximum vesical volume (not significant). These findings indicated that Gosha-Jinki-Gan is a useful drug for the treatment of pollakiuria.

[Regional and chronological differences of urogenital cancer deaths in Japan]

PURPOSE

We investigated the changing patterns of urogenital cancer deaths during the past 22 years in Japan.

METHODS

We analyzed patients that died from cancer of the prostate, bladder and kidney between 1973-1994. Age-adjusted death rates (adjusted to the world population), standardized mortality ratios (SMR) according to each prefectures and age-specific death rates for each types of cancer were calculated and changes in these patterns were analyzed.

RESULTS

Age-adjusted death rates for cancer of the prostate increased from 2.29 in 1973 to 4.36 in 1994, a 1.9-fold increase. Death rates for cancer of the bladder were stable in males and declined in females. Death rates for cancer of the kidney (15 years or older) increased from 1.45 in 1973 to 2.72 in 1994, a 1.9-fold increase in males, and tended to increase in females as well. In the SMR analysis by prefecture, distribution in 1973-84 (former period) and that in 1985-94 (later period) were similar, and characteristic features were observed for each type of cancer. Age-specific death rates for cancer of the prostate and bladder rose by an index power of age, but that for cancer of the kidney reached a plateau or decreased after an index power increase to a certain age. The rate of increase in age-specific death rates (later period/former period) rose according to age, especially 70 years or older, in cancer of the prostate and kidney in both males and females. However, age-specific death rates in the later period from cancer of the bladder was higher only in patients 85 years or older, but was lower in other age groups.

CONCLUSIONS

Death rates for cancer of the prostate and kidney (15 years or older) tended to increase, while that of the bladder remained stable or decreased. It is expected that detection and treatment of these disease can be improved by utilizing these epidemiologic information.

[How to select and use urate lowering agents for hyperuricemia]

Two classes of urate lowering agents, i.e. uricosuric agents and allopurinol, are available for the treatment of hyperuricemia. To prevent the formation of urinary urate stones and possible damage to liver function, it is recommended to use uricosuric agents in those patients with underexcretion of urate, and allopurinol in those with overproduction. Urinary uric acid/creatinine ratio is a convenient index to determine these phenotypes. These agents should be started to prescribe from the minimal dose to prevent the gouty arthritis which is easily evoked in the first several months after the introduction of these agents. An uric acid level between 5.0 and 6.4 mg/dl had minimal occurence of gouty attack during the first six months of the drug therapy.

[Alcohol ingestion and hyperuricemia]

Purine nucleotide degradation during ethanol catabolism, inhibition of renal excretion of urate by lactic acid, and high purine content of certain kinds of beverage are responsible for the elevation of serum uric acid level following alcohol drinking. It is well documented that rapid consumption of ATP produces uric acid via purine nucleotide degradation. Since individuals with ALDH2*1 can catalyze ethanol readily, they consume large amount of ATP, and thus produce more hypoxanthine than those with ALDH2*2. Thus, daily drinker and heavy drinker tend to readily induce hyperuricemia after alcohol ingestion. A high purine content in beer may contribute to the increasing frequency of hyperuricemia. Restriction of any kind of alcohol beverages, especially beer, is necessary in the medical control of patients with gout or hyperuricemia.

Vitamin D3 elicits calcium response and activates blood monocyte-derived macrophages from patients with vitamin D dependent rickets type II

We studied the effects of vitamin D3 metabolites on intracellular free Ca2+ concentration ([Ca2+]i) and the respiratory burst of monocyte-derived macrophages (MDM) from patients with vitamin D dependent rickets type II. Treatment of MDM from the patients and healthy donors with 1 nM 1,25(OH)2D3 produced a rapid elevation of [Ca2+]i and similarly primed both types of cells for enhanced capacity for O2- release with phorbol diester. These results suggest that macrophages may have distinct non-genomic pathways of vitamin D3, which partly explain the absence of immunodeficiency and the disappearance of rickets after treatment with vitamin D3 in the patients.

Contrast enhancement of PC-3 prostate cancer for magnetic resonance imaging: animal studies using tumor-localizing Mn-metalloporphyrin (THF-Mn-Asp)

PURPOSE

The objective of the present study was to test, in nude mouse PC-3 tumors, the contrast enhancement of 2,4-bis(1-tetrahydro-fulfuroxyethyl)-deuteroporphynyl(IX)-6- 7-bisaspartic acid (THF-Mn-ASP), which is a hematoporphyrin derivative and depresses T1 relaxation time on magnetic resonance (MR) imaging.

MATERIALS AND METHODS

THF-Mn-ASP or gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) was intravenously administered, and MR imaging of the tumors transplanted into nude mice was performed on T1-weighted images.

RESULTS

After administration of THF-Mn-Asp, the signal intensity of PC-3 tumors increased and the tumor/muscle intensity ratio was highest at about 1 hour. The tumor/muscle intensity ratio, in contrast, was highest at about 5 minutes after administration of Gd-DTPA. The increase in intensity ratio was 32% in THF-Mn-ASP and 28% in Gd-DTPA.

CONCLUSION

The preliminary study suggested that THF-Mn-Asp has a predilection to accumulate in PC-3 tumors, and it seems to provide good contrast enhancement with tumor specificity for MR imaging.

Sequence analysis of presenilin-1 gene mutation in Japanese Alzheimer's disease patients

The mutations of presenilins (PSs) gene and their clinicopathological correlations to Alzheimer's disease (AD) have lately attracted considerable attention. In this report we analyzed fifteen Japanese familial Alzheimer's disease (FAD) including 12 early-onset FAD and 13 sporadic AD patients for the mutation of PS-1 gene by direct sequence analysis. We found the mutations, G384A, E280A in two FAD and H163R in one sporadic AD patient, and no N1411 or M239V mutation in PS-2 gene, and no mutation in exons 16 and 17 in amyloid precursor protein (APP) gene. Families in which we failed to find the mutation by this screening may have mutations elsewhere in PSs or in APP gene, or yet unidentified other AD loci may exist. This is the first report to find a sporadic AD patient having PS-1 mutation.

The origin of the most common mutation of adenine phosphoribosyltransferase among Japanese goes back to a prehistoric era

The incidence of adenine phosphoribosyltransferase (APRT) deficiency is higher among Japanese nationals than among other ethnic groups, and the most common mutation (APRT*J, ATG to ACG mutation at codon 136) accounts for 68% of the disease-causing genes among Japanese. To investigate the origin of these mutations, we studied the geographical distribution of the mutant genes in Japan. The APRT*J mutation is distributed nearly uniformly in the four main islands of Japan and Okinawa, suggesting a very early origin. The products of PCR amplification between positions 2344 and 2750 of the genomic APRT sequence were examined by SSCP analysis in random blood samples from Japanese, Korean, and Taiwanese nationals. Among 955 random Japanese blood samples, 7 (0.73%) were heterozygous for the APRT*J mutation, giving a calculated heterozygote frequency of 1.1% among Japanese for the entire APRT deficiency. None of 231 Taiwanese samples contained heterozygotes for the APRT*J mutation, while 2 (0.53%) of 356 Korean samples were heterozygous. In addition to the APRT*J sequence, a total of five variant sequences was found. Sequencing one variant revealed a base substitution in intron 4, suggesting therefore that they are harmless mutations. Since the APRT*J mutation is present in Koreans and Okinawans who share ancestors only before the Yayoi era (third century BC to third century AD), the origin of the APRT*J mutation predates 300 BC.

Similarity of in vivo somatic mutations at an autosomal adenine phosphoribosyltransferase locus between T- and B-cells in human peripheral blood

In vivo somatic mutations have been detected at several human loci by using clonal cultures of peripheral blood T-cells. It has not been fully understood whether or not the somatic mutations in T-cells are similar to those of other cell types. To address this issue, we cloned, from human peripheral blood, T- and B-cells with mutations at an autosomal adenine phosphoribosyltransferase (APRT) locus. For the efficient detection of somatic mutations at the APRT locus, a blood sample from a human individual heterozygous for germline APRT deficiency was used. T- and B-cells deficient in APRT enzyme activity were cloned from peripheral blood mononuclear cells using a selecting agent, 2,6-diaminopurine. The APRT-deficient mutant frequencies were on the order of 10(-4) in both T- and B-cells. The single-strand conformation polymorphism analysis of the APRT DNA of mutant B-cell clones suggested that the molecular mechanisms leading to the APRT deficiency in B-cells were similar to those in T-cells. Our observations suggest that both the frequency and the mode of in vivo somatic mutations occurring spontaneously at general autosomal loci in B-cells are similar to those in T-cells.

Differential binding avidities of human IgM for staphylococcal protein A derive from specific germ-line VH3 gene usage

Human IgM that express the variable region genes of the VH3 family bind staphylococcal protein A (SPA). We previously reported that the SPA-binding IgM can be divided into two groups based on the differential binding avidities for solid-phase SPA. To study the molecular basis for these differences, we cloned B cells from human blood by EBV transformation. The nucleotide sequences of the expressed Ig heavy chain genes were determined on 20 B cell clones that produce SPA-binding IgM. The germ-line VH3 gene usage in IgM with high avidities for SPA were distinct from the germ-line VH3 genes used in IgM with low avidities for SPA. There was no correlation in the usage of D or JH genes or in the usage of light chains in IgM according to the SPA binding avidity. These results suggest that the differential binding avidities for SPA are at least partly due to specific germ-line VH3 gene usage. An investigation of direct binding of SPA to the synthetic peptides corresponding to the portions of the variable regions of SPA-binding and non-SPA-binding IgM showed that the peptides corresponding to the VH3 family specific framework region 3 sequences had significant SPA binding capacities, while the peptides corresponding to the other subdomains and those corresponding to framework region 3 of the reported VH3 sequences from non-SPA-binding IgM showed little or no binding. It is of interest that the Ig-framework region 3 subdomain corresponds to the fourth hypervariable region, which in the TCR-beta chain has been implicated as a critical site for T cell superantigen binding.

[The mass screening for prostate cancer and the age eligibility. Gunma Urological Oncology Study Group]

BACKGROUND

The age eligibility for the mass screening (MS) for prostate cancer was investigated.

METHODS AND MATERIALS

This study was performed in subjects examined by MS from 1981 to 1994 in Gunma Prefecture, Japan. MS was performed by digital rectal examination (DRE) and prostatic acid phosphatase from 1981 to 1991, and by DRE, transrectal ultrasonography and prostate specific antigen from 1992 to 1994.

RESULTS

It was demonstrated that the prostate cancer detection rate was affected by the ratio of subjects newly and previously examined, the age distribution in the group examined and the diagnostic modality. It was also demonstrated that the detection rate of early stage prostate cancer was also affected by the age distribution and the diagnostic modality. The effective detection rate was determined on the assumption that the purpose of MS is the detection of the subjects who have the indication for the radical prostatectomy, and the effective detection rate was calculated in the range from 50 to 69 years for age eligibility, and B and C for clinical stage. It was estimated that effective detection rate was 0.37 to 0.61%. They were higher than the detection rate of MS for other organ cancers.

CONCLUSION

The eligibility is 50 to 69 years. If subjects in the range of 70 to 74 are included in this project, it is necessary to make an effort practice a subject-education about the prostate cancer natural history and the radical prostatectomy indication.

Differential binding avidities of human IgM for staphylococcal protein A derive from specific germ-line VH3 gene usage

Human IgM that express the variable region genes of the VH3 family bind staphylococcal protein A (SPA). We previously reported that the SPA-binding IgM can be divided into two groups based on the differential binding avidities for solid-phase SPA. To study the molecular basis for these differences, we cloned B cells from human blood by EBV transformation. The nucleotide sequences of the expressed Ig heavy chain genes were determined on 20 B cell clones that produce SPA-binding IgM. The germ-line VH3 gene usage in IgM with high avidities for SPA were distinct from the germ-line VH3 genes used in IgM with low avidities for SPA. There was no correlation in the usage of D or JH genes or in the usage of light chains in IgM according to the SPA binding avidity. These results suggest that the differential binding avidities for SPA are at least partly due to specific germ-line VH3 gene usage. An investigation of direct binding of SPA to the synthetic peptides corresponding to the portions of the variable regions of SPA-binding and non-SPA-binding IgM showed that the peptides corresponding to the VH3 family specific framework region 3 sequences had significant SPA binding capacities, while the peptides corresponding to the other subdomains and those corresponding to framework region 3 of the reported VH3 sequences from non-SPA-binding IgM showed little or no binding. It is of interest that the Ig-framework region 3 subdomain corresponds to the fourth hypervariable region, which in the TCR-beta chain has been implicated as a critical site for T cell superantigen binding.

Serial changes in proximal urethral function after transurethral balloon laser hyperthermia of the prostate (TUBAL-H) in a canine model

We performed transurethral balloon laser hyperthermia of the prostate (TUBAL-H) in 6 mongrel dogs. To evaluate the changes in proximal urethral function after TUBAL-H, the urethral cross sectional area (CSA, cm2) and urethral pressure (Pu, cmH2O) were measured using a balloon probe that allows their simultaneous measurement, and the urethral compliance (Comp, cm3/cmH2O) was calculated from these parameters and serially evaluated. In addition, the changes in Pu, CSA and Comp after administration of an alpha-adrenoceptor antagonist were evaluated before and 16 weeks after TUBAL-H. Before TUBAL-H, the mean Comp was 0.013, and the mean maximum CSA (MCSA) was 0.66. Eight weeks after TUBAL-H, the mean Comp was 0.038, and the mean MCSA was 1.39, showing a significant increase (p < 0.01). Sixteen weeks, after TUBAL-H, the mean Comp was 0.026, and the mean MCSA was 1.21, being lower than those at 8 weeks after TUBAL-H, but significantly higher than those before TUBAL-H (p < 0.05). After administration of the alpha-adrenoceptor antagonist, phentolamine (1 mg/kg), before TUBAL-H, the mean Comp significantly increased to 0.046 (p < 0.05), and the mean MCSA to 1.40 (p < 0.01). The mean Comp was significantly increased to 0.033 (p < 0.05), by phentolamine administration 16 weeks after TUBAL-H, but no other changes were observed. After TUBAL-H, urethral elasticity increased, and this increase persisted for 4 months. The responses of Comp and MCSA to alpha-adrenoceptor antagonist administration before and 16 weeks after TUBAL-H suggested that part of the effects of TUBAL-H is due to damage to alpha-adrenoceptors.

Preparation of Bragg gratings in sputter-deposited GeO(2)-SiO(2) glasses by excimer-laser irradiation

GeO(2) - SiO(2) thin glass films were prepared by the rfsputtering deposition method. Changes in the refractive index of -3% and in the volume of +18% were induced in the film by irradiation with excimer-laser pulses. Bragg gratings a (periodic surface-relief pattern with a sinusoidal wave) have been written in the film by irradiation through a phase mask.