Assessment of high-energy phosphorus compounds in the rat kidney by in situ31P nuclear magnetic resonance spectroscopy: effect of ischemia and furosemide

Summary ³¹P nuclear magnetic resonance (NMR) spectroscopy of the in situ rat kidney was performed by a surface coil method, and the effects of ischemia and furosemide infusion were assessed.³¹P NMR spectra of the kidney subjected to 30 min of ischemia returned completely to the pre-ischemic level after 60 min of reperfusion. But the³¹P NMR spectra after 60 min of ischemia did not recover, even after 120 min of reperfusion. Levels of -ATP and inorganic phosphate (Pi) decreased and the chemical shift of Pi increased after intravenous infusion of furosemide. This increase in chemical shift might signal an alkalotic change in intracellular pH. Furosemide infusion prior to ischemia is thought to protect the kidney from injury induced by 60 min of warm ischemia. The chemical shift of Pi returned to the pre-ischemic level earlier than -ATP and Pi. In conclusion, according to the findings of³¹P NMR spectroscopy, furosemide infusion prior to ischemia may be effective in protecting the kidney against ischemic injury. But the change in Pi peak and the causes of the dissociation of Pi and -ATP should be examined further.     

Influence of ETR-p1/f1 antisense peptide on endothelin-induced constriction in rat renal arcuate arteries

1. This study set out to examine the endothelin receptor subtypes mediating vasoconstriction in the rat renal arcuate artery. This was done in isolated vessels 120–200 μm in diameter, incubated with a selective agonist and the novel ‘antisense'' peptide to part of the human endothelin_A receptor.
2. Groups of vessels (n=6) were incubated with increasing concentrations of endothelin-1 (ET-1), from 1 to 100 nM, which caused a 65% maximal contraction at the highest dose with an pEC₅₀ of 8.16±0.11 M. By contrast, in six other vessels sarafotoxin 6c over the same dose range gave a minimal contraction (around 5% of maximum).
3. Preincubation of six vessels with the antisense peptide ETR p₁/f1 at 1 μM had no effect on the ET-1 induced vasoconstriction, in terms of displacement of the concentration-response curve or the maximal tension achieved by the agonist. In the six vessels exposed to 4 μM ETR p₁/f1, there was a significant shift of the concentration-response curve and a lower pEC₅₀ at 7.78±0.09 M (P<0.05). At the highest concentrations of ETR p₁/f1, there was a marked suppression of all responses to ET-1, which at the maximal concentrations tested, 0.1 μM, only reached some 10% of the maximal achievable contraction.
4. Increasing ET-1 concentrations up to 2 μM in vessels incubated with 40 μM ETR-p₁/f1 showed that the blockade could be overcome and that the relationship was shifted to the right (P<0.001) by approximately one log unit with a pEC₅₀ of 7.13±0.11 M. A Schild plot of the data indicated the antagonist to be acting competitively at a single population of receptors.
5. At the highest concentrations tested, 40 μM, ETR-p₁/f1 had no effect on noradrenaline-induced contractions, indicating a lack of non-specific actions.
6. Together, these data suggest that at the rat renal arcuate artery the endothelin_A receptor is the predominant functional receptor mediating contraction. Furthermore, this study has shown the potential usefulness of this novel type of ‘antisense'' peptide in blocking receptor activation.

     

Influence of 1 alpha,25-dihydroxyvitamin D-3 on growth regulation through epidermal growth factor receptor in human breast cancer cell lines

We investigated the relationship between epidermal growth factor (EGF) dependent cell growth and antiproliferative effects of 1 alpha,25-dihydroxyvitamin D-3 (1,25(OH)(2)D-3) in hormone responsive breast cancer cell lines in vitro. MCF-7 breast cancer cells and GMC-M, which is a serum-independent, hormone receptor-positive subtype derived from MCF-7, were used in this study. EGF stimulated the growth Of both cell lines, and 1,25(OH)(2)D-3 inhibited the EGF-stimulated cell growth in a dose dependent fashion. But treatment with 1,25(OH)(2)D-3 did not change the EGF receptor (EGFR) level significantly in either cell line. GMC-M had a higher level of EGFR and was more sensitive to EGF than MCF-7. These results suggest that other mechanisms of action, which are different from EGFR modulation, concern with the growth inhibitory effect of 1,25(OH)(2)D-3, and that 1,25(OH)(2)D-3 will be a new effective treatment for breast cancer irrespective of EGFR.     

Computer-aided diagnosis in full digital mammography

RATIONALE AND OBJECTIVES: The authors clarify the detection rates for breast cancerous tumors and clustered microcalcifications with computer-aided diagnosis (CAD) based on Fuji Computed Radiography. The authors also determine whether mammographic reading with CAD contributes to the discovery of breast cancer. METHODS: Data acquired by Fuji Computed Radiography 9000, which consisted of 4148 digital mammograms including 267 cases of breast cancer, was transferred directly to an analysis workstation where an original software program determined extraction rates for breast tumors and clustered microcalcifications. Furthermore, using another 344 mammograms from 86 women, observer performance studies were conducted on five doctors for receiver operating characteristic (ROC) analysis. RESULTS: Sensitivity to breast cancerous tumors and clustered microcalcifications were 89.9% and 92.8%, respectively false-positive rates were 1.35 and 0.40 per image, respectively. The observer performance studies indicate that an average Az value for the five doctors was greater with the CAD system than with a film-only reading without CAD, and that a reading with CAD was significantly superior at P < 0.022. CONCLUSIONS: It has been shown that CAD based on Fuji Computed Radiography offers good detection rates for both breast cancerous tumors and clustered microcalcifications, and that the reading of mammograms with this CAD system would provide potential improvement in diagnostic accuracy for breast cancer.     

Pure apraxic agraphia with abnormal writing stroke sequences: report of a Japanese patient with a left superior parietal haemorrhage

A 67 year old Japanese male patient had pure agraphia after a haemorrhage in the left superior parietal lobule. He developed difficulty in letter formation but showed no linguistic errors, consistent with the criteria of apraxic agraphia. He manifested a selective disorder of sequencing writing strokes, although he was able to orally state the correct sequences. The patient's complete recovery after 1 month, without new learning, showed that he had manifested a selective disorder of writing stroke sequences. These findings indicate that the final stage of the execution of writing according to acquired sequential memory shown as a stroke sequence can be selectively disturbed, and should be considered to be distinct from the ability of character imagery and the knowledge of the writing stroke sequence itself. This case also indicates that the left superior parietal lobule plays an important part in the execution of writing.     

Effects of long-term treatment with trandolapril on augmented vasoconstriction in rats with chronic heart failure

Background:

Despite the clinical relevance of angiotensin I-converting enzyme (ACE)inhibitors, their effects on impaired vascular function in patients and animals with chronic heart failure (CHF) have not been fully understood. This study was undertaken to determine whether long-term treatment with an ACE inhibitor improved the altered contractile properties of vessels from rats with CHF.

Methods and Results:

Twelve weeks after coronary artery ligation, the rats were sacrificed and the isometric tension development of thoracic aorta, pulmonary artery, and mesenteric artery with and without endothelium was examined. Contractile responses to norepinephrine and prostaglandin F₂α were augmented in endothelium-intact, but not in endothelium-denuded, thoracic aorta and pulmonary artery segments of the rat with CHF. The contractile response to angiotensin II was augmented in endothelium-denuded mesenteric artery segments of the rat with CHF, which was attenuated by indomethacin or diclofenac sodium but not by bunazosin. Trandolapril (3 mg/kg/d) was administered orally from the 2nd to 12th week after the operation. Treatment with trandolapril reversed the augmented contractile response of the rat with CHF to norepinephrine, prostaglandin F₂α, and angiotensin II almost to the levels in the sham-operated rat.

Conclusions:

The results demonstrate that an ACE inhibitor is capable of reversing altered vascular function in the rat with CHF, suggesting that vascular beds are possible sites of action for ACE inhibitors in the therapy for CHF.     

Hyperthermo-chemotherapy combined with cytoreductive surgery for the treatment of gastric cancer with peritoneal dissemination

Continuous hyperthermic peritoneal perfusion (CHPP) with anticancer agents (mitomycin C and cisplatin) in warm saline was performed in patients with peritoneal dissemination of gastric cancer following resection of the primary lesion. The effect of CHPP was examined by a second-look operation. This study includes 41 cases of gastric cancer with peritoneal dissemination but without liver metastasis treated during the past 6 years. The overall median survival was 14.6 months to 64.2 months from CHPP to death and the 3-year survival rate was 28.5%. Second look surgery revealed a remarkable diminution in the degree of peritoneal dissemination in 7 (50%) of 14 patients with disappearance of ascites after only one course of CHPP in 7 (77.8%) of 9 patients. Long-term 3 year-survival was noted in 4 (9.8%) patients on CHPP. Side effects were renal insufficiency in 2 (5%) patients, leukopenia in 2 (5%) patients, and perforation of the small intestine in 1 (2%) patient. These results suggest the effectiveness of CHPP in the treatment of gastric cancer with peritoneal dissemination.

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Resumen La perfusión hipertérmica continua (PHTC) con agentes anticancerosos (mitocina G y cisplatino) y solutión salina fue realizada en pacientes con cáncer gástrico con diseminación peritoneal después de resección de la lesión primaria, y el efecto de PHTC fue determinado mediante reexploración (operación de second look, OSL). La población de pacientes está constituída por 41 casos de cáncer gástrico con diseminación peritoneal pero sin metástasis hepáticas, tratdos en el curso de los últimos 6 años. La sobrevida media global fue de 437 dias (rango 28 a 1925 días) desde la PHTC hasta la muerte y la tasa de sobrevida a 3 años fue 28.5%. La OSL reveló una notoria disminución de la diseminación peritoneal en 7 (50%) de 14 casos y desaparición de la ascites después de sólo un ciclo de PHTC en 7 de 9 casos con ascitis. Sobrevida de 3 años ocurrió en 4 casos. Los efectos colaterales fueron insuficiencia renal en 2 casos (5%), leucopenia en 2 casos (5%) y perforación del intestino delgado en 1 caso (2%). Los anteriores resultados sugieren que la PHTC es eficaz en el tratamiento del cáncer gástrico con diseminación peritoneal.

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Résumé La perfusion péritonéale continue hyperthermique (PPCH) avec des agents anticancéreux comme le mitomycine C et la cis-platine avec sérum physiologique chauffé a été instaurée lorsqu'une carcinose d'origine gastrique a été trouvée. Les effets de la PCH ont été évalués chez 16 patients lors d'un second-look (SL). Cette étude concerne 41 patients avec carcinose péritonéale sans métastase hépatique observés au cours des 6 dernières années. La survie globale médiane était de 437 jours (extrêmes 28 à 1925 jours): le taux de survie a 3 ans était de 28.5%. Les lésions avaient diminué de façon notable chez 7 (50%) de 14 patients. L'ascite a disparu dans 7 des 9 cas. Une survie à long terme (3 ans) a été notée dans 4 cas. Les effets secondaires ont été une insuffisance rénale dans 2 cas (5%), une leucopénie dans 2 cas (5%) et une perforation de l'intestin grêle dans un cas (2%). Les résultats suggèrent que la PPCH est efficace dans le traitement du cancer gastrique avec dissémination péritonéale.

     

A randomized, double-blind, placebo-controlled trial of the effects of rofecoxib, a selective cyclooxygenase-2 inhibitor, on rectal polyps in familial adenomatous polyposis patients.

PURPOSE: The aim of this study was to examine the effect of a specific cyclooxygenase-2 inhibitor, rofecoxib, on rectal polyps in familial adenomatous polyposis patients. EXPERIMENTAL DESIGN: This was a randomized, double-blind, placebo-controlled study of the efficacy and safety of rofecoxib in the rectum. Initially, 21 patients were assigned randomly in a 1:1 ratio to receive either 25 mg rofecoxib once a day or a placebo p.o. for 9 months. Patients underwent endoscopy at the beginning of the study and then every 3 months thereafter. We reviewed the videotapes to measure the number and size of polyps in the same area throughout the study period in each individual patient. RESULTS: The polyp number, measured as the percentage of change from the baseline values, was significantly decreased in the rofecoxib group at 3, 6, and 9 months. At 9 months, the polyp number in the rofecoxib group decreased by 6.8% from the baseline values, whereas that in the placebo group increased by 3.1%. The 9.9% difference between the rofecoxib and placebo groups was statistically significant (P = 0.004). At 9 months, the rofecoxib group showed a significant reduction from the baseline in polyp size as compared with the placebo group (-16.2% versus 1.5%; P < 0.001). There was no statistically significant increase in the incidence of any adverse events in treatment with rofecoxib compared with placebo (P = 0.922). CONCLUSIONS: In this study, once-daily treatment with 25 mg rofecoxib, a cyclooxygenase 2-specific inhibitor, significantly decreased the number and size of rectal polyps in familial adenomatous polyposis patients.     

Induction of Squamous Cell Carcinomas in the Salivary Glands of Rats by Potassium Iodide

In a 2-year carcinogenicity study of potassium iodide (KI) in F344/DuCrj rats, squamous cell carcinomas (SCCs) were observed in the salivary glands of 4/40 males and 3/40 females receiving 1000 ppm KI in the drinking water. Ductular proliferation with lobular atrophy was observed at high incidence in the submandibular glands of the high-dose animals, and squamous metaplasia was frequently evident within the proliferative ductules and the larger interlobular ducts. A transition from metaplasia to SCC was apparent. The results suggest that squamous metaplasia in proliferative ductules, occurring secondarily to lobular impairment induced by KI, may develop into SCCs via a non-genotoxic, proliferation-dependent mechanism.