Cloning and functional expression of a new water channel abundantly expressed in the testis permeable to water, glycerol, and urea

A new member of the aquaporin (AQP) family has been identified from rat testis. This gene, referred as aquaporin 7 (AQP7), encodes a 269-amino acid protein that contained the conserved NPA motifs of MIP family proteins. AQP7 has the amino acid sequence homology with other aquaporins ( approximately 30%), and it is highest with AQP3 (48%), suggesting that both AQP3 and AQP7 belong to a subfamily in the MIP family. Injection of AQP7-cRNA into Xenopus oocytes expressed a 26-kDa protein detected by immunoblotting. The expression of AQP7 in oocytes stimulated the osmotic water permeability by 10-fold which was not inhibited by 0.3 mM mercury chloride. The Arrhenius activation energy for the stimulated water permeability was low (2.1 kcal/mol). AQP7 also facilitated glycerol and urea transport by 5- and 9-fold, respectively. The activation energy for glycerol was also low (5.3 kcal/mol after the correction of the endogenous glycerol permeability of oocytes). Northern blot analysis revealed a 1.5-kilobase pair transcript expressed abundantly in testis. In situ hybridization of testis revealed the expression of AQP7 at late spermatids in seminiferous tubules. The immunohistochemistry of testis localized the AQP7 expression at late spermatids and at maturing sperms. AQP7 may play an important role in sperm function.

Small peptides switch the transcriptional activity of Shavenbaby during Drosophila embryogenesis

A substantial proportion of eukaryotic transcripts are considered to be noncoding RNAs because they contain only short open reading frames (sORFs). Recent findings suggest, however, that some sORFs encode small bioactive peptides. Here, we show that peptides of 11 to 32 amino acids encoded by the polished rice (pri) sORF gene control epidermal differentiation in Drosophila by modifying the transcription factor Shavenbaby (Svb). Pri peptides trigger the amino-terminal truncation of the Svb protein, which converts Svb from a repressor to an activator. Our results demonstrate that during Drosophila embryogenesis, Pri sORF peptides provide a strict temporal control to the transcriptional program of epidermal morphogenesis.

Cloning and functional expression of a second new aquaporin abundantly expressed in testis

A new member of water channels has been identified from rat testis. This gene, termed aquaporin 8 (AQP8), encoded a 263-amino-acid protein that contained the conserved NPA motifs of MIP family proteins. AQP8 has amino acid sequence identity with other aquaporins (approximately 35%) and highest with a plant water channel, AQP-gamma TIP (39%), suggesting that AQP8 is a unique member in mammalian aquaporins. The expression of AQP8 in Xenopus oocytes stimulated the osmotic water permeability (Pr) 8.5 folds. The increase of Pr was inhibited with 0.3 mM mercury chloride by 55%, which was reversed with mercaptoethanol. The Arrhenius activation energy for the stimulated water permeability was low (5.1 kcal/mol). AQP8 did not facilitate glycerol transport. Northern blot analysis revealed a 1.5-kb transcript of AQP8 abundantly in testis and slightly in liver. In situ hybridization of testis revealed the expression of AQP8 mRNA in all stages of spermatogenesis from primary spermatocytes to spermatids in seminiferous tubules. Together with previously cloned AQP7, AQP8 may also play an important role in spermatogenesis. The unexpected complexity of the presence of two aquaporins in testis may call for the further analysis of the role of aquaporins in the reproduction biology.

Association and spreading of the Drosophila dosage compensation complex from a discrete roX1 chromatin entry site

In Drosophila, dosage compensation is controlled by the male-specific lethal (MSL) complex consisting of MSL proteins and roX RNAs. The MSL complex is specifically localized on the male X chromosome to increase its expression approximately 2-fold. We recently proposed a model for the targeted assembly of the MSL complex, in which initial binding occurs at approximately 35 dispersed chromatin entry sites, followed by spreading in cis into flanking regions. Here, we analyze one of the chromatin entry sites, the roX1 gene, to determine which sequences are sufficient to recruit the MSL complex. We found association and spreading of the MSL complex from roX1 transgenes in the absence of detectable roX1 RNA synthesis from the transgene. We mapped the recruitment activity to a 217 bp roX1 fragment that shows male-specific DNase hypersensitivity and can be preferentially cross-linked in vivo to the MSL complex. When inserted on autosomes, this small roX1 segment is sufficient to produce an ectopic chromatin entry site that can nucleate binding and spreading of the MSL complex hundreds of kilobases into neighboring regions.

Regulation of the EDG84A gene by FTZ-F1 during metamorphosis in Drosophila melanogaster

The transcription factor FTZ-F1 is a member of the nuclear hormone receptor superfamily and is transiently expressed during the mid- and late prepupal periods in Drosophila melanogaster. A putative pupal cuticle gene, EDG84A, is expressed slightly following FTZ-F1 expression during the prepupal period and carries a strong FTZ-F1 binding site between bases 100 and 92 upstream of its transcription start site. In this study, EDG84A mRNA was found to be prematurely expressed upon heat induction of FTZ-F1 in prepupae carrying the heat shock promoter-FTZ-F1 cDNA fusion gene construct. Transgenic fly lines having the 0.8-kb region of the EDG84A promoter fused to lacZ expressed the reporter gene in a tissue- and stage-specific manner. Base substitutions in the FTZ-F1 binding site within the 0.8-kb promoter abolished expression of lacZ. These results strongly suggest that the EDG84A gene is a direct target of FTZ-F1. Deletion studies of the cis-regulatory region of the EDG84A gene revealed that space-specific expression in imaginal disc-derived epidermis is controlled by the region between bp -408 and -104 from the transcription start site. The region between bp -408 and -194 is necessary to repress expression in a posterior part of the body, while the region between bp -193 and -104 carries a positive element for activation in an anterior part of the body. These results suggest that FTZ-F1 governs expression of the EDG84A gene in conjunction with putative tissue-specific regulators.

Requirement of Notch 1 and its ligand jagged 2 expressions for spermatogenesis in rat and human testes

It has already been demonstrated that the Notch signaling system is essential for gametogenesis in the adult germ line of Caenorhabditis elegans. However, the role of the Notch signaling system in mammalian spermatogenesis has not been well investigated. Recently, it has been revealed that this signaling system is expressed in the mammalian testis by showing coexpression of Jagged 2 and its receptor, Notch 1, is consistent with Notch 1 being a cognate receptor for Jagged 2 in the mammalian testis. Therefore, we investigated expressions of messenger RNAs of Notch 1 and Jagged 2 in the testicular tissues of developing Sprague-Dawley rats by reverse transcription-polymerase chain reaction and Northern blot analysis, expressions of their proteins in the testicular tissues of developing rats, fertile human controls and infertile human patients with maturation arrest by immunohistochemistry, and effects of antibodies to this system by culturing rat testicular tissues with these antibodies. Transcripts of Notch 1 and Jagged 2 in the rat testis were positive throughout the examined period; these intensities became higher at day 13 after birth, coincidence with the formation of spermatocytes, and peaked at day 19 after birth. Expressions of Notch 1 and Jagged 2 were recognized at first in the perinuclear regions of spermatocytes in the rat testis as a round structure at day 19 after birth and thereafter in further differentiated germ cells as meiosis proceeded. In the adult rat testis, positive staining was present as a round structure in spermatocytes, as a typical horseshoe-shaped structure in round spermatids, and as a covering structure spreading around the nucleus of elongated spermatids, but not in spermatozoa. Notch 1 was recognized in the vacuole of the Golgi complex of primary spermatocytes and the acrosome of elongated spermatids with electron microscopy. When rat testicular tissues were cultured with anti-Notch 1 or anti-Jagged 2 antibody, round and elongated spermatids decreased after 5 and 7 days of culture, respectively, and disappeared at around 9 and 12 days of culture, respectively, with shrinkage of the diameter of seminiferous tubules. Spermatocytes, however, increased after 11 days of culture. Expressions of both proteins have been detected in the testicular tissues of human fertile controls as in the rat testicular tissues. However, Notch 1 expression has not been detected in testicular tissues of 11 patients with maturation arrest, whereas Jagged 2 expression has been recognized in all of them. In conclusion, the results presented in this study offer the possibility that Notch 1/Jagged 2 signaling system plays an important role for male germ cells to differentiate or at least to survive in the rat testis and fails to express in the testis of spermatogenic maturation arrest patients.

Impaired Delta Np63 expression associates with reduced beta-catenin and aggressive phenotypes of urothelial neoplasms

p63, a homologue of the p53 gene, is considered to be essential for the normal development of stratified epithelia including urothelium. To examine possible roles of p63 in urothelial tumorigenesis, p63 expression was systematically examined in normal urothelium, low-grade papillary noninvasive (LPN) urothelial tumours, and high-grade or invasive carcinomas, using either an isoform-nonspecific or a Delta N-isoform-specific antibody. Expression profiles of p63 were also analysed in cultured cells. Immunoreactivity with the two antibodies was virtually identical in tissue samples examined. Basal and intermediate cell layers of normal urothelium showed intense nuclear p63 immunostaining. This normal staining pattern was preserved in a majority of LPN tumours, whereas it was frequently impaired in high-grade or muscle-invasive carcinomas. At the mRNA level, Delta Np63 expression predominated over TAp63, and amounts of Delta Np63 mRNA correlated with p63 immunoreactivity, confirming that Delta Np63 accounts for p63 expressed in urothelial tissues. In cultured cells, Delta Np63 was also expressed in low-grade tumour cells as well as normal urothelial cells, but undetectable in high-grade aggressive carcinoma cells. Interestingly, impaired Delta Np63 expression significantly associated with reduced beta-catenin expression that was possibly related to progression of urothelial neoplasms. Thus, impaired Delta Np63 expression characterises aggressive phenotypes of urothelial neoplasms.

Temporal regulation of the mid-prepupal gene FTZ-F1: DHR3 early late gene product is one of the plural positive regulators

BACKGROUND

Various ecdysteroid responsive genes play important roles in insect moulting and metamorphosis. Late FTZ-F1, a member of the nuclear receptor superfamily, is a unique transcription factor which is induced by a pulse exposure of 20-hydroxyecdysone. Elucidation of the regulation mechanism of this gene during prepupal period will help our understanding of metamorphosis at a molecular level.

RESULTS

Using transgenic fly lines carrying various transcription regulatory regions of the FTZ-F1 gene fused to the LacZ gene, we investigated cis-regulatory elements in the late FTZ-F1 transcription unit. The region which governs the stage-specific expression during prepupal period was narrowed down to 1.2kb, from -0.7 to +0.5kb relative to the transcription start site. Electrophoresis mobility shift assays using staged extracts and various probes within the stage-specific region allowed us to identify binding sites for DHR3, an early late gene product, around 170 and 450bp downstream of the transcription initiation site. Mutations disrupting these binding sites reduced the reporter gene expression without affecting the stage specificity.

CONCLUSIONS

Our deletion and mutation studies of the cis-regulatory element of the FTZ-F1 gene suggest that the DHR3 binding sites located in the 5' non-coding region are involved in the prepupal expression of the gene. These DHR3 binding sites confer high level expression while other elements are also involved in stage-specific expression.

Molecular characterization of human Aquaporin-7 gene and its chromosomal mapping

The cDNA for the seventh mammalian aquaporin (AQP7) was isolated from rat testis, and its expression demonstrated at the tail of late spermatids (Ishibashi et al., J. Biol. Chem. 272 (1997) 20,782-20,786). Here we report the isolation of the mouse and the human AQP7 cDNA and the human AQP7 gene. The human AQP7 gene is identical with human adipose AQP (AQPap or AQP7L). The deduced amino acid sequences of human and mouse AQP7 were 68% and 79% identical to those of rat AQP7, respectively. The mouse AQP7 is 67% identical to the human AQP7. Such a lower conservation of AQP7 among species is unusual in the aquaporin family. The human AQP7 gene is composed of six exons distributing over 6.5 kb. The exon-intron boundaries are identical to those of the human AQP3 gene. The intron sizes are also similar. Moreover, chromosomal localization of AQP7 was assigned to 9p13 by fluorescent in situ hybridization, where AQP3 is also localized, suggesting that 9p13 may be another site of an aquaporin cluster.

Hypertensive mechanisms associated with centrally administered aldosterone in dogs

The mechanism by which intracerebroventricularly administered aldosterone increases arterial pressure was investigated in trained, conscious dogs with cannulas chronically implanted in a lateral cerebral ventricle. In salt-replete and salt-depleted dogs, artificial cerebrospinal fluid with or without aldosterone (0.05 microgram/kg/hr) was infused intracerebroventricularly for 12 days by an osmotic minipump. A similar dose of aldosterone was infused subcutaneously for 12 days. Aldosterone infused intracerebroventricularly increased blood pressure significantly in both salt-replete and salt-depleted dogs. In salt-replete animals the hypertension was associated with increased total peripheral resistance without concomitant changes in blood volume, cardiac output, or in any of the neurohumoral parameters measured. We conclude that this type of hypertension is resistance-mediated from its outset and appears to be relatively independent of salt and water retention. The mechanism by which intracerebroventricularly administered aldosterone increases vascular resistance remains to be determined.

Cerebral vein disorders and postoperative brain damage associated with the pterional approach in aneurysm surgery

The possible causes of postoperative brain damage were examined in 100 cases of cerebral aneurysms operated on by the pterional approach. Postoperative brain damage occurred in 15% of cases, located mostly in the inferior frontal lobe. Its incidence was higher in early than in delayed operation and increased with severity of preoperative clinical conditions but not correlated with patient age and aneurysm location. The venous perfusion patterns in the inferior frontal lobe were classified into three types based on preoperative venograms: Sylvian type drained mainly into the superficial Sylvian veins (SSVs), Frontal type drained mainly into the frontal bridging veins, and Intermediate type. Postoperative brain damage was most frequent in the Sylvian type with statistical significance (p < 0.01). The brain retraction procedure impairs regional cerebral blood flow (rCBF). Venous congestion in the retracted inferior frontal lobe, caused by stretching and narrowing of SSVs due to both brain retraction and dissection of the Sylvian fissure, also reduces rCBF. Thus, a marked reduction in rCBF in the retracted area causes postoperative brain damage. Postoperative venograms showed the SSVs to be obscured in 24% of patients, indicating that the pterional approach possibly influences the SSV perfusion. A venous perfusion disorder during the pterional approach is the most important factor in postoperative brain damage, and careful preoperative assessment of cerebral veins is indispensable.

Regulation of vascular endothelial growth factor transcription by endothelial PAS domain protein 1 (EPAS1) and possible involvement of EPAS1 in the angiogenesis of renal cell carcinoma

BACKGROUND

Endothelial PAS domain protein 1 (EPAS1) is a basic helix-loop-helix/PAS domain transcription factor that expressed most abundantly in highly vascularized organs. The authors examined the effect of transfection of EPAS1 cDNA on the endogenous expression of vascular endothelial growth factor (VEGF) in the 293 Tet-Off cell line and the possible involvement of EPAS1 in the angiogenesis of renal cell carcinoma (RCC).

METHODS

Complete cDNA of EPAS1 was cloned and transfected to cells from the 293 Tet-Off fetal kidney cell line, in which the expression of EPAS1 can be inhibited by doxycycline. The subsequent changes in expression pattern of VEGF and transferrin receptor (TfR), a target gene of hypoxia-inducible factor 1alpha (HIF-1alpha), were examined by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay. In addition, expression of EPAS1, HIF-1alpha, and VEGF were analyzed by semiquantitative RT-PCR in five RCC cell lines and in 13 RCC tissue samples. In situ hybridization was performed on 7 of the 13 RCC tissue samples.

RESULTS

Endogenous VEGF was increased significantly by the introduction of EPAS1 cDNA at both the mRNA level and the protein level. With the inhibition of EPAS1 by doxycycline treatment, the expression of VEGF was significantly decreased accordingly, whereas the expression of TfR was not affected. EPAS1 was detected in all of the RCC cell lines examined. In RCC tissue samples, EPAS1 mRNA and VEGF mRNA were increased significantly in tumor tissues compared with normal adjacent kidney tissues. In situ hybridization showed that EPAS1 and VEGF were coexpressed topographically in tumor tissues.

CONCLUSIONS

These results suggest that endogenous VEGF can be up-regulated transcriptionally by EPAS1, and EPAS1 may be involved in the angiogenesis of RCC.

Expression of aquaporins 7 and 8 in the developing rat testis

Aquaporin (AQP) is a molecule that facilitates water permeability through cell membranes and is widely distributed in the mammalian body. Among members of the AQP family, AQP7 and AQP8 are predominantly expressed in the testis. This paper examined the expression of these two AQPs in the developing rat testis, using northern blot and immunohistochemistry to visualize their roles during the progression of spermatogenesis in the developing testis. In adult rats, expression of AQP7 was localized to spermatids, whereas AQP8 protein was observed in spermatocytes. In the developing testis, transcripts of AQP7 became detectable between 23 and 25 days post-partum, when round spermatids have been reported to appear. On the other hand, AQP8 mRNA was first detected between 13 and 16 days post-partum, consistent with the reported first appearance of spermatocytes (13-14 days). AQP7 and AQP8 proteins were detectable at 28 days post-partum. The results suggest that AQP7 and AQP8 appear in the testis in accordance with the maturation of germ cells, and are involved in spermatogenesis.

Guilt by association: non-coding RNAs, chromosome-specific proteins and dosage compensation in Drosophila

Dosage compensation is a striking example of the interplay between gene-specific regulation and chromosomal architecture. This process has evolved to make X-linked gene expression equivalent in males with one X chromosome and females with two. Examining species at the molecular level has shown that dosage compensation is mediated by sex-specific factors that decorate the X chromosomes to regulate chromatin structure and gene expression. In Drosophila, dosage compensation is achieved, at least in part, through site-specific histone H4 acetylation, which is modulated by a male- and X-specific protein complex. The discovery of non-coding RNAs that 'paint' dosage-compensated X chromosomes in mammals and in Drosophila suggests that RNAs play an intriguing, unexpected role in the regulation of chromatin structure and gene expression.

Glycyrrhizin induces mineralocorticoid activity through alterations in cortisol metabolism in the human kidney

It has been suggested that the mineralocorticoid action of glycyrrhizin is caused by a defect in the conversion of cortisol to cortisone through inhibition of the enzyme 11 beta-dehydrogenase (11 beta-DH). We investigated the functional significance of the inhibition of this enzyme as a mechanism of the mineralocorticoid action of glycyrrhizin. Eighteen healthy volunteers were divided into three groups of six and treated as follows: (1) 225 mg glycyrrhizin/day, (2) 0.1 mg 9 alpha-fluorocortisol (FC)/day and (3) 225 mg glycyrrhizin and 1.5 mg dexamethasone/day, all of which were given for 7 days. The administration of glycyrrhizin or FC induced a similar mineralocorticoid effect; specifically, suppression of plasma renin activity, hypokalaemia and kaliuresis. During the concomitant administration of glycyrrhizin and dexamethasone, however, these mineralocorticoid effects were significantly attenuated. During the administration of glycyrrhizin, urinary excretion of cortisol increased without change in the plasma levels of cortisol, while both plasma level and urinary excretion of cortisone decreased. Changes in cortisol metabolism were not observed during the administration of FC. These results demonstrated the functional significance of the inhibition of 11 beta-DH in the mineralocorticoid activity of glycyrrhizin in man.

Clinical anatomic study of pure dysarthria

Nine patients with pure dysarthria underwent computed tomography or magnetic resonance imaging. Eight patients had infarcts of lacunar or larger size in the internal capsule: four in the superior portion of the anterior limb or adjacent corona radiata and four in the superior portion of the genu or the adjacent corona radiata. In one patient, there was a small infarct in the bulbar motor cortex. Dysarthria was transient and characterized by poor articulation in all cases. Five patients also had contralateral facial weakness, and three patients with lesions in the genu had minimal and transient involvement of the contralateral fingers. These three cases appeared to be variants of the dysarthria-clumsy hand syndrome. We submit that this syndrome should sometimes be regarded as a stroke syndrome rather than always as a lacunar syndrome.

Effects of endothelin on systemic and renal haemodynamics and neuroendocrine hormones in conscious dogs

1. The effects of endothelin on systemic and renal haemodynamics and plasma concentrations of neuroendocrine hormones including plasma renin activity, aldosterone, adrenocorticotropic hormone, cortisol, catecholamines and arginine vasopressin were investigated in 18 conscious dogs. 2. Bolus injection of 4 pmol of endothelin/kg did not cause any significant changes in haemodynamics. Mean arterial pressure was elevated by both doses of 40 pmol/kg [91 +/- 2 to 99 +/- 2 mmHg (12.1 +/- 0.3 to 13.2 +/- 0.3 kPa), P less than 0.05] or 200 pmol/kg [93 +/- 2 to 107 +/- 3 mmHg (12.4 +/- 0.3 to 14.3 +/- 0.4 kPa), P less than 0.01], the latter dose increasing cardiac output (14%, P less than 0.05) and heart rate (9%, P less than 0.05), and the former reducing these parameters (14% and 8%, P less than 0.05, respectively). 3. In contrast with the various changes in systemic haemodynamics, renal blood flow transiently increased immediately after bolus injection in a dose-dependent manner (28%, P less than 0.05, 50%, P less than 0.01 and 110%, P less than 0.01 with 4, 40 and 200 pmol of endothelin/kg, respectively). This transient elevation of renal blood flow was followed by a gradual decrease (16%, P less than 0.05; 31%, P less than 0.01 and 36%, P less than 0.01) at 10 min. 4. All neurohormones were elevated in a dose-dependent manner.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of infliximab on bone metabolism markers in patients with rheumatoid arthritis

OBJECTIVE

The aim of this study was to evaluate urinary excretion of N-telopeptide of type I collagen (NTX) and deoxypyridinoline (DPD), markers of bone resorption, and serum bone alkaline phosphatase (BAP) level, a marker of bone formation and an early marker of osteoblast differentiation, in patients with rheumatoid arthritis (RA) treated with infliximab.

METHODS

Seventeen male and female patients (age 60.7+/-2.53 yr; mean disease duration 12.9+/-3.01 yr; Steinbrocker's class II-IV) with RA, diagnosed according to the criteria of the American College of Rheumatology (ACR), took part in the study between March 2003 and January 2005. None of the patients had a history of oestrogen replacement therapy. All patients were treated with infliximab combined with methotrexate. Infliximab was infused intravenously at 3 mg/kg at baseline, 2 and 6 weeks, then every 8 weeks. To evaluate disease activity, ESR, CRP, the numbers of swollen and tender joints, modified Stanford Health Assessment Questionnaire (mHAQ) score and ACR score were measured. Levels of NTX and DPD in urine and BAP in serum were measured in all patients.

RESULTS

ESR, CRP, the number of swollen joints and tender joints, and mHAQ score had decreased significantly 6 weeks after initial treatment and were still low 6 months after initial treatment. NTX levels had decreased significantly 6 weeks after the initial treatment and were still low 6 months after initial treatment. DPD levels had decreased 6 months after initial infusion. Mean serum BAP level did not differ significantly among the three time points. NTX levels were statistically corresponding with the number of swollen joints and mHAQ scores. DPD levels were statistically lower corresponding with ESR.

CONCLUSION

Infliximab therapy may inhibit generalized bone loss in patients with RA. NTX is a more sensitive marker than DPD.

Significance of bladder neck involvement on progression in superficial bladder cancer

OBJECTIVES

To determine the significance of bladder neck involvement in predicting disease progression in superficial (stage Ta and T1) transitional cell carcinoma (TCC) of the urinary bladder.

PATIENTS AND METHODS

A series of 277 patients with newly diagnosed superficial TCCs of the bladder was reviewed, and disease progression (to T2 or worse) was considered. The significance of several risk factors including bladder neck involvement was assessed in univariate and multivariate analysis.

RESULTS

Progression occurred in 28 (10.1%) of 277 patients during a median follow-up period of 7.7 years. Nineteen died of bladder cancer. The following variables were found to be statistically significant at the univariate analysis (p < 0.05): irritative symptoms, urine cytology, tumor stage, involvement of the bladder neck, and tumor grade. Indeed, only involvement of the bladder neck, tumor stage, and grade retained their value as independent factors for progression at multivariate analysis. Patients were divided into three groups according to the number of independent risk factors they had. Groups having none, one, and two or three risk factors included 129, 99, and 49 patients with 5-year progression rates of 0.8, 4.6 and 27.5%, and 15-year rates of 4.0, 20.1 and 42.7%, respectively.

CONCLUSION

Involvement of the bladder neck is a significant and independent risk factor for progression of superficial TCCs in addition to the histologic grade and stage. The combination of these three risk factors offers better prediction of progression in an individual patient.

Successful treatment of metastatic adenocarcinoma of the urachus: report of 2 cases with more than 10-year survival

Metastatic urachal cancer is often considered lethal. We report 2 cases of metastatic urachal carcinoma successfully treated with surgical excision followed by combinations of surgery, radiation, and chemotherapy against local recurrence and/or distant metastases, with a recurrence-free survival period of more than 10 years. These cases provide support for multimodal treatments of metastatic urachal cancer.

Oral calcium treatment lowers blood pressure in renovascular hypertensive rats by suppressing the renin-angiotensin system

The effects of calcium supplementation on blood pressure and its mechanisms were investigated in two-kidney, one clip renovascular hypertensive rats. Two series of experiments were performed: one was begun just after renal artery constriction, the other after the onset of hypertension. Calcium supplementation significantly attenuated the development of hypertension (systolic blood pressure: 183 +/- 8 vs 130 +/- 2 mm Hg) and was found to abate existing renovascular hypertension (systolic blood pressure: from 183 +/- 8 to 151 +/- 4 mm Hg). Calcium treatment did not cause significant alterations in fluid intake, urine volume, or urinary sodium excretion in either study. However, increased plasma renin activity and plasma aldosterone concentration were suppressed to the basal levels at the end of 3 weeks of calcium treatment (14 +/- 3 vs 8 +/- 2 ng angiotensin I/ml/hr; 530 +/- 50 vs 380 +/- 40 pg/ml). Blood pressure of calcium-treated renovascular hypertensive rats responded poorly to blockade of the renin-angiotensin system with captopril injection and angiotensin II analogue (saralasin) infusion. Further, in rats with chronic established renovascular hypertension, calcium treatment attenuated the enhanced pressor response to norepinephrine, but not to angiotensin II. These results suggest that the blood pressure-lowering actions of calcium supplementation are related primarily to suppression of renin secretion and secondarily to alteration of pressor response to norepinephrine in two-kidney, one clip renovascular hypertensive rats.

Apoptosis is involved in acute cardiac allograft rejection in rats

BACKGROUND

Allograft rejection remains a major obstacle to long-term survival in heart transplantation. Recent studies have demonstrated that apoptotic cell death may occur in acute allograft rejection. The purpose of this study was to determine whether apoptotic cell death is involved in rat cardiac allograft rejection through both the perforin/granzyme pathway and the Fas/Fas ligand (Fas-L) pathway.

METHODS

Groups of Lewis (RT1(1)) rats underwent heterotopic heart transplantation from disparate DA (RT1a) or syngeneic Lewis rats. The cardiac grafts were harvested 1, 3, or 5 days after transplantation and analyzed for apoptotic cell death using DNA nick-end labeling, immunocytochemistry, and electron microscopy. In addition, the expression of granzyme B, perforin, Fas, and Fas-L messenger RNA were analyzed by reverse transcriptase-polymerase chain reaction.

RESULTS

Apoptotic cell death of cardiac myocytes was prominent in allografts on day 5 after transplantation. Fas gene transcripts were constitutively expressed in both syngeneic and allogeneic grafts, whereas expression of Fas-L was only upregulated in allografts with ongoing rejection. Granzyme B and perforin gene expression were also upregulated in allografts with ongoing rejection.

CONCLUSIONS

These results suggest that myocyte apoptosis through both the perforin-granzyme pathway and the Fas-Fas-L pathway may be involved in cardiac allograft rejection in rats.

Detection of disseminated urothelial cancer cells in peripheral venous blood by a cytokeratin 20-specific nested reverse transcriptase-polymerase chain reaction

More than half of all patients with invasive urothelial cancer subsequently develop metastatic disease even after radical resection of the primary cancer. In these patients, neoplastic cells may be disseminated prior to or during the operation. A nested reverse transcriptase-polymerase chain reaction (nested RT-PCR) assay which amplifies cytokeratin (CK) 20 transcripts was used to detect cancer cells in the peripheral blood of urothelial patients. This assay was able to detect 10 bladder cancer cell line cells in a sample of ten million peripheral-blood mononuclear (PBMN) cells. CK 20-specific signals were detected in 9 (22.5%) of 40 PBMN cell samples prepared from 40 urothelial cancer patients in relation to the tumor stage, including 0/13 patients with a superficial tumor, 4/21 (19%) with a regionally invasive tumor and 5/6 (83%) with a metastatic tumor (P = 0.0002 in chi 2 test). No signals were detected in any of 25 healthy donor PBMN cell samples. The present results indicate that the CK 20 RT-PCR assay is applicable for detection of urothelial cancer cells in the peripheral blood. The assay also confirms that hematogenic dissemination occurs in invasive urothelial cancers but rarely in superficial ones.