Partial cloning of prohibitin cDNA from canine, feline, bovine, equine, and rabbit liver mRNA by RT-PCR

Prohibitin is the protein which has an inhibitory function in cell growth, and its gene is suggested to be one of putative tumor suppressor genes. In this report, we described a partial cloning of prohibitin cDNAs from canine, feline, bovine, equine, and rabbit liver mRNAs by RT-PCR, and their homology analysis. The sequences of these RT-PCR products were compared with each other as well as those reported for human and rat. The homology in this region of prohibitin cDNA was approximately 90%, and the amino acid sequence of each RT-PCR product shared more than 95% identity. Therefore, it is concluded that all the RT-PCR products are a part of prohibitin cDNA of each animal.

Prolactin expresses differential effects on apoptotic cell death of luteal cells in vivo and in vitro

PRL surges in female rats have dual effects of luteal function: either inducing luteolysis during the estrous cycle or rescuing and maintaining luteal function during pseudopregnancy. We analyzed these apparent contradictory effects in relation to apoptosis. The detection of fragmented DNA and in situ 3'-end labeling studies were done on corpora lutea (CL) collected from cycling rats at proestrus 1800 h (P1800 specimen) or pseudopregnant rats on day 6 (psp 6). Distinct DNA ladders were observed in P1800 samples as we previously reported, but only slight ones were found in psp 6 specimen. The effect of PRL on the induction of apoptosis was evaluated in vitro with dispersed luteal tissue. CL from cycling rats were exempted from a PRL surge by pre-treating donors with a dopamine agonist. The extent of apoptotic reaction in P1800 specimen depended on the doses of PRL added to the culture medium. In psp 6 specimen, in contrast, PRL suppressed the apoptotic reaction, increased the cell survival rate (MTT assay), and decreased the cell death rate (LDH assay). Furthermore, PRL enhanced 20 alpha-hydroxysteroid dehydrogenase activity in P1800 specimen but suppressed it in psp 6 specimen. In summary, PRL in rats is either an apoptosis-inducer or -suppressor, depending on the functional state of luteal cells.

A fraction unresponsive to growth inhibition by TGF-beta among the high-proliferative potential progenitor cells in bone marrow of p53-deficient mice

Transforming growth factor-beta (TGF-beta) has been found to block the progression of the cell-cycle by up-regulating a Cdk inhibitor, p15, only in epithelial cells; on the other hand, wild-type p53 was shown to activate transcriptionally the gene for another Cdk inhibitor, p21. The regulatory effects of TGF-beta on hematopoietic tissues is poorly understood. Hence, we investigated the effect of TGF-beta on hematopoietic progenitor cells in p53-deficient mice to determine whether an inhibitory signal from TGF-beta is linked to p53 in hematopoietic regulation. We found that the proliferation of megakaryocyte-progenitors (CFU-Mk) in our wild-type mice was markedly inhibited by TGF-beta. Contrary to an earlier report, an erythroid and a granulocyte-macrophage progenitor, stimulated by IL-3, were not significantly inhibited, whereas TGF-beta also completely inhibited the growth of high-proliferative potential progenitor cells (HPP-CFC) in the marrow of mice with 5-fluorouracil (5FU), as reported. It is interesting that in the p53-deficient mice, the inhibitory action of TGF-beta on the HPP-CFC was incompletely abolished. The response curve we obtained for graded doses of TGF-beta suggests that there is, at least, a subpopulation of HPP-CFC which is less sensitive to the regulation by TGF-beta. In contrast to HPP-CFC, the CFU-Mk, which TGF-beta inhibited only in wild-type mice not treated with 5FU, remained inhibited in the p53-deficient strain. Thus, HPP-CFC might be regulated by TGF-beta through their signal pathways which are linked to p53.

MRI findings in the liver in biliary atresia patients after the Kasai operation

To evaluate liver function in biliary atresia (BA) patients after the Kasai operation, magnetic resonance imaging (MRI) was carried out 28 times in 19 BA patients. Sixteen of these were divided into three groups on the basis of the serum level of total bilirubin (t-bil), glutamic pyruvic transaminase (GPT) and gamma-glutamyltransferase (gamma-GTP) in the postoperative follow-up period (2-11 years). In group 1 (n = 7) the t-bil was continuously kept under 1 mg/100 ml. In group 2 (n = 4) the t-bil was continuously kept under 1 mg/100 ml, but GPT and gamma-GTP remained high (GPT > 100 IU/liter, gamma-GTP > 200 IU/ liter) for more than 2 years. In group 3 (n = 5) an increase in the t-bil level reappeared (1-2 mg/100 ml; n = 4, > 2 mg/100 ml; n = 1). The differences between MRI finding in the 3 groups, and the correlation between MRI findings and laboratory data (t-bil, cholinesterase; ChE, GPT and gamma-GTP), which were taken around the time of MRI examinations, were studied. The results were as follows: (1) All 19 patients had normal or high signal areas of various sizes on T1 weighted images (WI). (2) Eighteen of 19 patients had high signal areas of various sizes on T2 WI in the portal system areas and/or liver parenchyma, and these areas were enhanced by gadolinium-DTPA in about half of the patients. (3) Ten of 16 patients had atrophic change over one liver lobe. (4) MRI findings for group 1 and the other groups were significantly different, and MRI findings, except for atrophic change, were correlated with the increase or decrease in laboratory data taken around the time of MRI examinations (p < 0.05). These results indicate that a normal or high signal area on T1 WI shows functional tissue, and that a high signal area on T2 WI shows tissue damaged by inflammation and/or progressive fibrosis. MRI is useful for evaluating liver function, especially in terms of morphological features, in BA patients after the Kasai operation, and will be one method for establishing their prognosis.

The carboxyl-terminal region is essential for Sec-A dimerization

SecA, comprising 901 amino acid residues, exists as a dimer. By means of size exclusion chromatography and chemical cross-linking analysis, five truncated SecA derivatives were examined to identify the region of SecA essential for dimer formation. Among them, only N95 (delta 832-901) retained SecA activity. N95 existed as a dimer, indicating that the carboxyl-terminal three cysteine residues are dispensable for physiological dimerization. Both N76 (delta 675-901) and N66 (delta 583-901) existed as monomers. Monomeric N76 was able to bind to ATP, indicating that the dimerization of SecA is not a prerequisite for ATP binding. However, the rate of ATP hydrolysis by N76 was 25% of that by SecA. C53 (delta 1-437) and C28 (delta 1-661) formed dimers irrespective of the presence or absence of 2-mercaptoethanol. C28, but not C53, also existed as an oligomer in the absence of 2-mercaptoethanol, suggesting that the 438-661 region present in C53 prevents intermolecular disulfide bond formation at the carboxyl-terminal cysteine residue. From these results, the region essential for the physiological dimer formation was concluded to be located in the 662-831 region of SecA.

Hepatic embolization through extrahepatic collateral pathways after hepatic arterial embolization for the hepatocellular carcinoma

Extrahepatic collateral pathways developing after repeated transcatheter arterial embolization (TAE) for hepatocellular carcinoma (HCC) make therapeutic arterial embolization for recurrent lesions extremely difficult. TAE was performed through the collateral pathways using a sophisticated micro-catheter with good trackability and pushability and a coaxial system. Twenty-three TAEs were undertaken through the collateral pathways in 13 patients with recurrent HCC who had extrahepatic collateral pathways after the previous hepatic arterial TAE. There were 69 extrahepatic collateral pathways, with partially obstructed hepatic arteries. On the average, three feeding arteries were seen in the liver. The main extrahepatic collateral pathways were the inferior phrenic artery and epicholedocal artery, 18 vessels and 29 vessels, respectively, accounting for about 80% of the total collateral pathways. TAEs were successful in all cases and the number of embolized vessels was 2.1 on average. The average time of the first collateral TAE after the initial conventional hepatic arterial TAE was 2.3 years. Excellent prognosis was observed with a one-year survival rate of 77% and 3-year survival rate of 38% after the collateral TAE. We consider that collateral TAE for recurrent HCC with obstruction of the hepatic artery is the procedure of choice, is technically feasible, and provides better prognosis for the patients.

Evaluation of patients with advanced neuroblastoma surviving more than 5 years after initiation of an intensive Japanese protocol: a report from the Study Group of Japan for Treatment of Advanced Neuroblastoma

In January 1985, a single protocol consisting of cyclophosphamide, vincristine, tetrahydropyranyl adriamycin, and cis-platinum for the treatment of advanced neuroblastoma was begun nationwide in Japan and was found to improve clinical results significantly in terms of 2- or 3-year survival rate. Between January 1985 and December 1988, 113 eligible patients (7 infants younger than 12 months of age with stage IVA disease and 106 patients aged 12 months or older with stage III or IV disease) were enrolled and followed up for 5 years or more after initiation of treatment, as of March 1994. In this study, the usefulness of the protocol for the treatment of advanced neuroblastoma was evaluated with survival rates in relation to age, tumor site, stage, and N-myc amplification for patients surviving more than 5 years after initiation of the protocol. Fifty of the 113 patients were alive 5 years or more after initiation of the treatment, 39 without any episodes of disease recurrence. Fourteen (70%) of 20 patients with stage III, 6 (50%) of 12 with stage IVB, and 24 (30%) of 81 with stage IVA disease were alive and disease-free 5 years after initiation of the protocol. Twenty (56%) of 36 patients without N-myc amplification were alive at 5 years after initiation of the protocol. Only one patient who was alive without evidence of the disease at 5 years had recurrence afterward.

[Immunologic analysis of milk, hen egg, and soybean proteins in butter and margarine, and clinical assessment for availability of hypoallergenic margarine (HAM)]

To determine the allergenic proteins in commercially available butter and margarine, protein fractions were extracted and immunologically analyzed against milk, hen egg, and soybean antigens. Butter and 10 kinds of margarine were proved to contain these proteins in various concentrations by ELISA and immunoblotting methods by use of the rabbit antisera developed against each food proteins. However, hypoallergenic margarine was found to contain no such proteins at all. Using sera obtained from atopic dermatitis patients, previously detected high levels of IgE antibodies to milk, hen egg, or soybeans, the extracted protein fraction from butter and margarine was analyzed whether these proteins react with IgG antibodies in patients' sera. The sera with high levels of specific IgE recognized protein antigens in these extracts except those from hypoallergenic margarine, suggesting that proteins in butter and margarine may become allergenic for the patients sensitive to the proteins, and that hypoallergenic margarine will be a reasonable alternative for the allergic patients to milk, hen egg, or soybeans.

Splenic macrophages can modify steroidogenesis of Leydig cells

A large amount of LH/hCG treatment given to male rats is known to suppress the enzyme activity of cytochrome P450c17 in Leydig cells for 48 h. A high dose LH/hCG injection is also known to allow immunocytes, such as macrophages, to migrate into the testicular interstitial compartment. It has not been known, however, whether these cells play a role in that suppression. In this study, we examined if splenic macrophages have any effects on testosterone secretion from Leydig cells by culturing rat testicular interstitial cells (TIC). Splenic macrophages co-cultured with TIC significantly suppressed testosterone secretion. Macrophages co-cultured reduced both progesterone to testosterone conversion and the amount of cytochrome P450c17 mRNA. The conditioned medium (SMCM), prepared by culturing macrophages for 12 h, significantly reduced either testosterone secretion from TIC or progesterone to testosterone conversion by TIC. These results indicate that splenic macrophages suppress testosterone secretion from Leydig cells by suppressing the cytochrome P450c17 enzyme in vitro, and that this effect is mediated at least in part by some soluble factors secreted from macrophages. Splenic macrophages migrating into the testis after LH/hCG stimulation could play a role in suppressing cytochrome P450c17 in Leydig cells.

[Low-dose radiation, therapy for choroidal neovascularization in age-related macular degeneration]

The efficacy of low-dose radiation was evaluated in the treatment of eyes with subfoveal or juxtafoveal choroidal neovascularization in age-related macular degeneration. Ten eyes of ten patients received a total dose of 14 Gy of 10 MV X-rays in seven fractions and the mean follow-up time was 12 months (range 9 approximately 18 months). Thirteen control eyes of thirteen patients were followed for an average of 18 months (range 12 approximately 24 months). Visual acuity was improved in 2 eyes (20%), unchanged in 3 eyes (30%), and deteriorated in 5 eyes (50%) of treated patients, and it was improved in no eyes (0%), unchanged in 5 eyes (32%), and deteriorated in 8 eyes (50%) of the control patients at their last follow-up examinations. Funduscopic and angiographic findings were improved in 3 eyes (30%), unchanged in 2 eyes (20%), and deteriorated in 5 eyes (50%) of treated patients, and they were improved in no eyes (0%), unchanged in 5 eyes (32%), and deteriorated in 8 eyes (50%) of the control patients. These results suggested that low-dose radiation is beneficial for the management of subfoveal or juxtafoveal choroidal neovascularization in age-related macular degeneration.

Regulation of glutamate release via NMDA and 5-HT1A receptors in guinea pig dentate gyrus

The regulation by 5-HT1A and N-methyl-D-aspartate (NMDA) receptors on the endogenous glutamate release was investigated in slices of guinea pig dentate gyrus. The release of glutamate was increased dose-dependently by the 5-HT1A receptor antagonist, NAN-190 at 0.01 to 300 nM, but was not affected by the 5-HT1A receptor agonist, 8-OH-DPAT even at 100 nM. The release of glutamate evoked by 0.1 microM NAN-190 was Ca(2+)-dependent, tetrodotoxin-sensitive and inhibited significantly by 8-OH-DPAT at 1, 10 and 100 nM. These results suggest that the 5-HT1A receptor, which is located postsynaptically on glutamatergic neurons, is involved in the inhibitory regulation of glutamate release. The release of glutamate evoked by 200 microM NMDA from dentate gyrus was inhibited significantly by pretreatment with 8-OH-DPAT at 1, 10 and 100 nM. The release of glutamate evoked by 0.1 microM NAN-190 was inhibited significantly by pretreatment with MK-801 at 1 and 10 microM, a selective non-competitive NMDA receptor antagonist. The release of glutamate evoked by NMDA at 25 and 75 microM from dentate gyrus was augmented by the concurrent application of 1 nM NAN-190. We propose that the glutamate release from guinea pig dentate gyrus is regulated both by the postsynaptic 5-HT1A receptor in an inhibitory manner and by the NMDA receptor in a stimulatory manner.

NMDA receptor activation induces glutamate release through nitric oxide synthesis in guinea pig dentate gyrus

We tested the hypothesis that the release of glutamate following activation of N-methyl-D-aspartate (NMDA) receptors is mediated by nitric oxide (NO) production, using slices of the guinea pig hippocampus. The NMDA-induced glutamate release from slices of dentate gyrus or CA1, which was both concentration-dependent and Ca(2+)-dependent, was also Mg(2+)-sensitive and abolished by MK-801, a selective non-competitive NMDA receptor antagonist. In dentate gyrus, the NMDA-induced glutamate release was inhibited non-significantly by tetrodotoxin, whereas the NO synthase (NOS) inhibitor NG-nitro-L-arginine (L-NNA) blocked the NMDA-induced release of glutamate in a concentration-dependent manner, but not a high K(+)-evoked release of glutamate. In addition, the L-NNA blockade of NMDA-induced release of glutamate was recovered by pretreatment with L-arginine, the normal substrate for NOS. These results suggest that activation of NMDA receptors in dentate gyrus, as well as subsequent Ca2+ fluxes, is required for the neuronal glutamate release mediated by NO production. On the other hand, the NMDA-evoked glutamate release from CA1 region was tetrodotoxin-sensitive and was not inhibited by L-NNA, thereby suggesting that activation of NMDA receptors in CA1 results in increased glutamate release in an NO-independent manner. Taken together, the NMDA receptor-mediated neuronal release of glutamate from the guinea pig dentate gyrus likely involves the recruitment of NOS activity.

Transcranial magnetic stimulation in an adrenoleukodystrophy patient

We experienced an 11-year-old boy diagnosed as having adrenoleukodystrophy (ALD), and studied his motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS). He had intellectual and visual impairment, and MRI revealed high intensity of the parieto-occipital white matter. On evaluation of the long tracts, slight spasticity with equivocal Babinski signs was noted: however, the long tracts appeared intact on MRI, and short latency somatosensory evoked potentials (SSEPs) were completely normal. On TMS delivered through a circular coil, MEPs recorded from the relaxed first dorsal interosseous muscle showed that only the duration was significantly prolonged, which may be due to temporal dispersion of descending volleys in the pyramidal tracts, while the latency was not prolonged. TMS in ALD was considered sensitive and useful for detecting subtle involvement of the long tracts.

Occurrence of deoxyribonucleic acid fragmentation during prolactin-induced structural luteolysis in cycling rats

We determined whether fragmentation of genomic DNA, one of the hallmarks of apoptosis, occurs during structural luteolysis in cycling rats. Corpora lutea (CL) were collected from rats at each estrous cycle stage (1800 h), and fragmented DNA was extracted. Only CL from rats at the proestrous stage showed distinct DNA fragmentation. To determine the period of occurrence of DNA fragmentation, CL were collected at several points between 1200 h on the day of proestrus and 0600 h on the day of estrus. Distinct DNA fragmentation was observed from 1800 h (proestrus) to 2400 h (proestrus), and the extent was significantly lower at 0600 h (estrus). It is known that prolactin (PRL) induces structural luteolysis in rats. To examine the role of PRL in luteal DNA fragmentation, 2-bromo-alpha-ergocryptine (BE) was used to suppress the PRL surge on the day of proestrus. CL collected at 1800 h from BE-treated rats did not show distinct DNA fragmentation, and PRL injection offset the effect of BE. Histochemical analysis with a 3'-end labeling technique confirmed the occurrence of DNA fragmentation in luteal tissue. These results suggest that apoptotic cell death occurs during PRL-induced structural luteolysis.

Massive apoptosis detected by in situ DNA nick end labeling in neuroblastoma

To seek evidence that tumor regression in neuroblastoma might result from massive apoptosis, we investigated tumor cell death in 39 neuroblastomas. Characteristic histologic features of apoptosis, condensed nuclear fragments and eosinophilic cytoplasm, were observed in all specimens. A ladder of DNA fragments induced by apoptosis was demonstrated by means of DNA agarose gel electrophoresis in 18 of the 19 tumors examined. In situ DNA nick end labeling (TUNEL) stained the nuclei with DNA fragmentation in 16 of 39 neuroblastomas. The TUNEL -positive cells were distributed in a scattered fashion in 10 tumors. In the remaining six tumors, they were densely located around nonviable areas of calcifications, where karyorrhectic or pyknotic cells were frequently observed. Five of six patients with such tumors were under 12 months of age, but there was no significant difference between the two groups in the patient age, origin of the primary lesion, or tumor stage. Biological features, including histology. DNA ploidy, and N-myc amplification, were not significantly different . Double fluorescent staining for bcl-2 oncoprotein and TUNEL showed that bcl-2 oncoprotein was expressed in the cytoplasm of tumor cells that were negative for TUNEL staining. This accumulated evidence suggests that massive apoptosis of tumor cells occurs in some neuroblastomas and may be related to tumor regression, whereas inhibition of apoptosis by bcl-2 oncoprotein expression might be associated with the tumorigenesis of neuroblastomas, as reported in our previous study.

[Renal toxicity of prulifloxacin (NM441) in rats]

Renal toxicity of prulifloxacin, a new antibacterial agent, was investigated in rats of both sexes. The animals were given prulifloxacin orally for 28 days at a dose of 3000 mg/kg. Tubular nephrosis in which crystalline substances appeared primarily within tubules was observed from the second day of administration, and a large number of brown circular crystals were found in the urinary sediment from the first day of administration. Electron microscopic observation revealed a close resemblance of the ultrastructural characteristics between the intratubular crystalline substance and the urinary brown circular crystal, and the tubules were occasionally occluded by the crystalline substances. Infrared spectral analysis and X-ray microanalysis indicated that the brown circular crystal consisted of NM394, an active metabolite of prulifloxacin. These results suggested that NM394, which was filtered into the primary urine, may be precipitated as crystals on the process of water reabsorption in the tubules. And then most of the crystals would be washed out as crystalluria particles, and some of crystals retained and caused the obstructive uropathy.

Varicella pneumonia in a healthy adult presenting with severe respiratory failure

We describe a case of varicella pneumonia in a 24-year-old healthy man presenting with severe respiratory failure. A chest radiograph showed diffuse, bilateral airspace consolidation; additional complications included liver dysfunction and thrombocytopenia. However, treatment with intravenous acyclovir and gamma-globulin improved his clinical symptoms and signs. A greater than four-fold change in paired titers of the varicella-zoster virus antibody was observed. Bronchoalveolar lavage performed during the recovery phase revealed increased total cell and lymphocyte counts and a decreased CD4:CD8 ratio of T lymphocytes. Transbronchial lung biopsy findings were compatible with a diagnosis of interstitial pneumonia.

Identification of putative 5-hydroxytryptamine(4) (5-HT4) receptors in guinea pig stomach: The effect of TKS159, a novel agonist, on gastric motility and acetylcholine release

We investigated the existence and the function of 5-hydroxytryptamine(4) (5-HT4) receptors and the effect of TKS159, a novel agonist of 5-HT4 receptor, on guinea pig stomach. The mechanical activity and the release of [3H]ACh were measured using preparations of muscle layers attached to intramural plexus from guinea pig stomach. 5-HT in the presence of 1 microM methysergide, 1 microM ketanserin and 1 microM granisetron, 5-methoxytryptamine or TKS159 enhanced the electrical transmural stimulation-evoked contraction and [3H]ACh release in strips of the stomach in a concentration-dependent manner. This enhancement by 5-HT, 5-methoxytryptamine or TKS159 was antagonized by SDZ 205-557 or atropine. Cisapride, metoclopramide and TKS159 enhanced the electrical transmural stimulation-evoked contraction and release of [3H]ACh in a concentration-dependent manner. We conclude that the pharmacological characteristics of the receptor, which mediates contraction of the guinea pig stomach by the activation of cholinergic nerves, are consistent with its being of the putative 5-HT4 receptor type and that TKS159 is an agonist at 5-HT4 receptors.

3,4-dihydroxyphenylalanine (DOPA) metabolism in screening-detected and non-screening-detected neuroblastoma

To investigate the possible clinical application of the hypothesis that insufficient induction of 3,4-dihydroxyphenylalanine decarboxylase (DDC) causes accumulation and secretion of 3,4-dihydroxyphenylalanine (DOPA) in unfavorable neuroblastomas, we measured plasma DOPA in 28 neuroblastoma patients. Abnormally high levels were demonstrated in patients with neuroblastoma, and the levels in patients with clinical manifestations (median, 44,800 pg/ml; range, 17,700 to 220,000 pg/ml; n = 6) were significantly higher than those in patients detected by screening (median, 5825 pg/ml; range 2890 to 33,300 pg/ml; n = 22) (P = 0.0004). The catecholamine secretion profiles of the two groups were different, and it was suggested that the relative deficiency of DDC caused DOPA secretion in patients in the former group, whose prognosis was unfavorable, except in one case. In both groups, serial determination of plasma DOPA was a good monitor of the disease course. The higher plasma DOPA level (>9400 pg/ml) was significantly correlated with the patients' age (>1 year old) (P = 0.019), tumor stage (III, IV) (P = 0.029), and DNA diploidy (P = 0.018). These results are consistent with previous studies that demonstrated plasma DOPA was a useful marker in the diagnosis and follow-up of neuroblastoma. The results also indicate that higher plasma DOPA levels are associated with the unfavorable characteristics of neuroblastoma, which seem to support the hypothesis on DDC deficiency in unfavorable neuroblastoma.

MR appearance of pulmonary metastatic calcification

We report a case of metastatic pulmonary calcification that showed hyperintense signal on T1-weighted MRI. This uncommon MR appearance of calcification is similar to the MR characteristics of calcification in the brain due to abnormal calcium metabolism.

Molecular cloning of DNA for inhibin alpha-subunit from equine ovary

cDNA encoding equine inhibin alpha-subunit precursor protein was isolated from an equine ovarian cDNA library. For screening, the DNA probe was amplified by the RT-PCR using primers designed based on the rat inhibin alpha-subunit cDNA sequence. Out of 1.2 x 10(5) plaques screened, 19 positive clones were isolated, and one of these clones (Eq-alpha-11) contained a complete open reading frame encoding 367 amino acids. The similarity of the deduced amino acid sequences of both equine inhibin alpha-subunit precursor protein and the mature protein were greater than 80% to those of other six mammalian species, including bovine, porcine, ovine, human, rat and mouse. Northern blot analysis revealed that a single major band at 1.5 kb was present in the RNA samples both from equine follicles and testes.

Treatment of a stage I testicular yolk sac tumor with vascular invasion

There is controversy concerning the treatment of stage I yolk sac tumor of the testis, particularly of those with histological factors that indicate a high risk of relapse. Usually orchiectomy alone is sufficient and adjuvant chemotherapy is unnecessary. Retroperitoneal lymphadenectomy is indicated for patients with persistently high alpha-fetoprotein. Once recurred, treatment at that time is thought to be curative. However, postoperative chemotherapy may be necessary for patients with a tumor expressing histological factors that predict possible relapse. In this paper we report on a case of a 2 year old boy whose tumor invaded the testicular veins. The patient suffered from recurrent disease but was successfully treated by chemotherapeutic regimens including cisplatin and retroperitoneal lymphadenectomy. The importance of the histological factors in making a decision on the treatment strategy for stage I testicular yolk sac tumor is discussed.

A novel periplasmic carrier protein involved in the sorting and transport of Escherichia coli lipoproteins destined for the outer membrane

Lipoproteins are localized in the outer or inner membrane of Escherichia coli, depending on the species of amino acid located next to the N-terminal fatty acylated Cys. The major outer membrane lipoprotein (Lpp) expressed in spheroplasts was, however, retained in the inner membrane as a mature form. A novel protein that is essential for the release of Lpp from the inner membrane was discovered in the periplasm and purified. The partial amino acid sequence of this 20 kDa protein (p20) was determined and used to clone a gene for p20. Sequencing of the gene revealed that p20 is synthesized as a precursor with a signal sequence. p20 formed a soluble complex only with outer membrane-directed lipoproteins such as Lpp, indicating that p20 plays a critical role in the sorting of lipoproteins. Lpp released from the inner membrane in the presence of p20 was specifically assembled into the outer membrane in vitro. These results indicate that p20 is a periplasmic carrier protein involved in the translocation of lipoproteins from the inner to the outer membrane.