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M Cano

Publications and source records attributed to M Cano.

At least 73 records · Page 4Linked to original sources
PubMed1993

Application of scanning electron microscopy and X-ray analysis to urinary tract cancer in animals and humans.

Scanning electron microscopy (SEM) has proven useful in various aspects of urinary bladder carcinogenesis research and these are reviewed as they pertain to our research involving sodium saccharin in the rat. Sodium saccharin-carcinogenesis in rats requires administration at high doses beginning at birth or earlier. Administration beginning at ages of 5 weeks or later results in much lower incidences of bladder tumors. Methods were developed for examining the rat fetal and neonatal bladder to further evaluate effects at these critical ages. Several significant differences were found by SEM between the fetal bladder compared to the adult. The typical polygonal superficial cells of the bladder with asymmetric unit membrane were present before birth, but the slow turnover rate of the adult bladder did not occur until 3-4 weeks of age. Sodium saccharin causes increased proliferation rates and hyperplasia of the urothelium which is dose-dependent. SEM was found to be more sensitive than either light microscopy or labeling indices to detect the earliest lesions induced by sodium saccharin. More recently, amorphous and crystalline material in the urine of rats fed high doses of sodium saccharin were detected by SEM examinations which contained silicon as well as calcium, phosphate, and magnesium as detected by energy dispersive X-ray analysis (EDS) with the SEM. These parameters may be relevant to differences between rats and humans and pertain to extrapolations regarding risk assessment.

Animals↗
PubMed1992

Acute urinary tract toxicity of tetraethylorthosilicate in rats.

Acute stomach, kidney, and bladder toxicity was evaluated in F344 rats after gastric gavage of tetraethylorthosilicate (TES) at daily doses of 0, 0.111, 0.223, and 0.333 g. Five rats of each sex at each dose were sacrificed after 1, 2, and 4 days. In TES-treated groups, silicate accumulated in the stomach glands and the muscle layer of the forestomach and glandular stomach. Serum chemistries demonstrated acute onset of renal failure. In the kidneys, acute tubular necrosis, accumulation of silicates, and superficial necrotizing papillitis were observed. In the renal pelvis and bladder, there was urothelial simple hyperplasia, focal erosion of the mucosa, edema, and inflammation. These acute toxic changes were dose and time dependent, but significant sex differences were not observed. The microscopic changes in the urothelium were similar to those observed following administration of high doses of sodium saccharin to male rats in which urinary silicate precipitate and crystals form.

Animals↗
PubMed1992

Removal of toxic metals and nonmetals from contaminated water.

The effects of the application of potassium ferrate to remove possible toxic compounds are presented. Potassium ferrate (K2FeO4) is shown in this work to be an effective means to remove toxic metals and nonmetals from aqueous solution. The toxic material present in water is precipitated from aqueous solution and readily removed. Potassium ferrate removes itself from solution. Discolored contaminated water may be made clear by utilizing potassium ferrate. In addition, turbidities of solutions induced by dissolved substances are eliminated by the action of potassium ferrate. The efficacy of potassium ferrate in cleaning contaminated water shows great potential in application to municipal and industrial waste water.

Chemical Precipitation↗
PubMed1992

Improvement of the hydrodynamic response of a ventricular assist device: a false auricle solution.

We propose a new design of the auricular cannula in ventricular assist devices (VADs), consisting of a collapsible large cannula with a capacity approximately equal to the ejection volume of the VAD. The device works as a false auricle and filters the negative pressure that occurs during diastole. We show that the use of this type of cannula improves the hydrodynamic efficiency and the stability of the working conditions. Moreover, during chronic implantation in sheep, hemolysis stays well below pathological levels. These improvements result in much better controllability of the whole VAD.

Animals↗
PubMed1991

First clinical implantation of the BCM 3.5 ventricular assist device (VAD).

We report on the first human implantation of the BCM 3.5 ventricular assist device in a 46-year-old man suffering from terminal stage cardiomyopathy. The circulatory support was used as a bridge to heart transplantation. The patient was in cardiogenic shock and was on assisted circulation for 18 days after which he underwent cardiac transplantation. While receiving support from the ventricular assist device, the patient's condition improved remarkably and 50 days after transplantation he was discharged from hospital. We give a detailed description of the surgical technique, with special emphasis on the procedures for air extraction. We describe the evolution of the hemodynamic status before and after implantation. Final inspection of the device and cannulae after removal showed no thrombi and only small fibrin deposits in the membrane-wall junction.

Cardiomyopathy, Dilated↗
PubMed1991

A proposed role for silicates and protein in the proliferative effects of saccharin on the male rat urothelium.

High doses of sodium saccharin, a non-genotoxic chemical, lead to the formation of silicate-containing precipitate and microcrystals in urine of male rats. Differences in urinary protein, pH, sodium and other factors affect silicate-containing precipitate and microcrystal formation as well as the bladder effects of sodium saccharin. Total urinary silicon concentration (mostly soluble) in sodium saccharin-fed rats is similar to or lower than the concentration in control rats. Binding of saccharin to male rat urinary proteins was demonstrated by equilibrium-gel filtration. We propose that by binding to urinary proteins under appropriate conditions, saccharin produces a nidus for the formation of silicate-containing precipitate and crystals. These appear to be cytotoxic to the superficial bladder epithelium, with cell death resulting in regenerative hyperplasia. Factors that influence the formation of these silicate-containing materials might provide a rationale for sex, species, dose and dietary differences in response to sodium saccharin.

Animals↗
PubMed1991

Pharmacokinetics of vancomycin in patients undergoing hemodialysis with polyacrylonitrile.

The pharmacokinetics of vancomycin in patients undergoing dialysis with cuprophane membranes are well known, however little has been reported of the use of polyacrylonitrile membranes in dialysis. We studied, in a crossover design, eight dialysis patients (7 men, 1 woman) aged 30 to 66 years who prospectively received 1 gram of vancomycin i.v. before first dialysis and were subsequently hemodialyzed with cuprophane every second day for a total of three times. A month later trial was repeated using polyacrylonitrile. A mono-compartment model was used to calculated pharmacokinetic parameters. Mean +/- standard deviation of vancomycin clearance varied from 5.2 +/- 2.1 ml/min in the interdialysis period to 9.7 +/- 2.7 ml/min during dialysis with cuprophane and to 58.4 +/- 15.6 ml/min during dialysis with polyacrylonitrile (p less than 0.001). Vancomycin half-life varied from 71.5 +/- 23.0 to 35.9 +/- 9.8 and to 6.1 +/- 1.4 hours, respectively (p less than 0.001). Fractional removal of vancomycin increased from 4% using the cuprophane dialyzer to 34% using the polyacrylonitrile dialyzer (p less than 0.001). Serum vancomycin levels at 100 and 168 hours were higher with cuprophane than with polyacrylonitrile (7.0 +/- 2.2 vs 3.9 +/- 1.2 micrograms/ml) (p less than 0.001). Moreover, the mean levels at 100 hours were suboptimal on polyacrylonitrile. Approximately 208 +/- 53 mg of vancomycin were removed during one polyacrylonitrile dialysis. Thus, those patients who undergo dialysis with polyacrylonitrile and are treated with vancomycin may need supplementary doses post dialysis or to lessen dosage intervals than those traditionally used for dialysis patients since clearance of the drug is significantly higher than with cuprophane dialyzers. Continuous monitoring of vancomycin levels is also recommended.

Acrylic Resins↗
PubMed1990

Intravitreal biocompatibility of mussel adhesive protein. A preliminary study.

Mussel adhesive protein (MAP) is a new tissue adhesive derived from the sea mussel Mytilus edulis. Rabbit eyes were injected intravitreally with 1 mg of MAP or balanced salt solution in order to determine the intraocular effects of this new biologic tissue adhesive. Two concentrations of MAP were used: one was undiluted and the other was diluted to a concentration of 1:10. A marked cellular inflammatory response, compared with the control eyes, was seen clinically in the vitreous cavity of animals in which MAP was used undiluted. This response persisted for up to two weeks and was suggestive of inflammatory response to a foreign protein. When MAP was used at a dilution of 1:10, a mild transient cellular reaction was observed in the vitreous; this cleared after seven days. There was no increase in intraocular pressure, and none of the eyes developed cataract or optic nerve damage. Fluorescein angiography demonstrated no vascular leakage and electroretinography was normal in all of the eyes at two weeks. Histopathologic evaluation of the eyes at 7 and 14 days after injection revealed localized cellular inflammation in the vitreous and adjacent retina when MAP was used undiluted, but no reaction in the control eyes or in eyes injected with MAP at 1:10 dilution. This preliminary study suggests that MAP produces a marked intraocular inflammatory reaction when used at full concentration. By diluting the adhesive, a less severe inflammatory response was observed, which cleared with no complications.

Animals↗
PubMed1990

Management of traumatic rupture of the globe in aphakic patients.

We report the successful treatment of three cases of traumatic ruptures of the globe complicated by massive choroidal hemorrhage, uveal prolapse and retinal detachment. All three of the eyes were aphakic prior to injury and all patients were age 64 or older. The presenting visual acuity in all patients was light perception. The blunt injury in each case caused a wound dehiscence at the site of previous cataract extraction. All injuries were associated with uveal prolapse. Secondary surgical intervention was performed when the hemorrhagic choroidal detachments had decreased as demonstrated by echography in the suprachoroidal space, occurring at an average of 14 days after injury. The management consisted of surgical drainage of the choroidal hemorrhage combined with vitrectomy and silicone oil injection. Successful reattachment of the retina was achieved in all cases. Postoperative epiretinal membranes formed in two cases but all were anatomically successful at six months. Final visual acuities varied from 20/70 to 1/200, visual acuity being a function of secondary contusive damage to the retina and choroid. We believe that in eyes sustaining severe blunt injuries resulting in rupture of the globe complicated by massive choroidal hemorrhage and retinal detachment, properly timed external drainage of the choroidal hemorrhage combined with pars plana vitrectomy and silicone oil injection is a useful approach.

Aged↗
PubMed1990

Comparative analysis of the proliferative response of the rat urinary bladder to sodium saccharin by light and scanning electron microscopy and autoradiography.

Three methods used to detect proliferative changes in the rat urothelium, light microscopy, scanning electron microscopy, and autoradiography, were compared for their sensitivity in detecting changes produced by administration of sodium saccharin. Weanling male F344 rats were fed sodium saccharin as 0, 3, 5, or 7.5% of the diet, and the bladders were evaluated after 4, 7, and 10 wks of feeding. Light microscopic changes and an increase in labeling index were seen at all time points in rats fed 7.5% sodium saccharin, but not at the lower doses. A slight increase in labeling index was also observed at 10 wks in the 5.0% group. Scanning electron microscopic changes were evident as early as 4 wks with increasing severity at the 3, 5, and 7.5% doses. This study demonstrates that the hyperplastic response of the urothelium to sodium saccharin administration varies with dose and time, and that observation by scanning electron microscopy is the most sensitive of the three methods evaluated for detecting these changes.

Animals↗
PubMed1989

Establishment of hamster pancreatic ductal carcinoma cell line (PC-1) producing blood group-related antigens.

A pancreatic cancer cell line, PC-1, was established from a pancreatic ductal carcinoma induced in a hamster by N-nitrosobis(2-oxopropyl)amine (BOP). The cells grew in a monolayer with a doubling time of 38 h, and floated or piled up to form a duct-like structure. Chromosome counts ranged from 42 to 89. Light and electron microscopic studies of PC-1 cells revealed production of conspicuous amounts of amorphous substance. Injection of PC-1 cells into the homologous hamster pancreas resulted in tumor formation, histopathologically indistinguishable from the original primary pancreatic ductal carcinoma. Immunohistochemical expression of blood group-related antigens (BGRAs), A, B, H, Leb, Lex and Ley was observed both in the cells in the culture, and in tumor transplanted into the pancreas. In the culture supernatant, a high titer of blood group A antigen was detected. This cell line may provide a unique tool for studying the mechanism of BGRA synthesis and release in malignant cells.

Animals↗
PubMed1989

Pituitary adenoma presenting as painful intermittent third nerve palsy.

We report the case of a woman with short nocturnal attacks of peri- and retro-orbital pain, diplopia, ptosis, rhinorrhea and lacrimation of five months evolution. Neurological examination was normal between attacks. The latter presented with partial third nerve palsy, which finally became complete and permanent. Brain CT showed a sellar and supraseller tumor with parasellar extension to the right side. We stress the atypical clinical presentation and evolution of this case, and discuss its pathophysiology.

Adenoma↗
PubMed1989

Morphological lesions of the rat urinary tract induced by inoculation of mycoplasmas and other urinary tract pathogens.

The effects on the urinary tract after inoculation of Ureaplasma urealyticum into the rat bladder were evaluated and compared to that seen after Mycoplasma hominis, Escherichia coli and Proteus mirabilis inoculation. The inoculation of the urease-producing organisms P. mirabilis and U. urealyticum were associated with the formation of struvite bladder stones and predominantly hyperplastic lesions of the bladder. The P. mirabilis inoculated rats also displayed marked pyelonephritis. A similar but much less pronounced reaction also occurred in the kidneys of some of the U. urealyticum inoculated rats. P. mirabilis could frequently be recultured. In contrast, this was not possible with U. urealyticum, but the organism was detected by scanning electron microscopy 2 weeks after the inoculation. Inoculation of M. hominis was associated with a few mild lesions of the bladder, but inflammatory lesions were not present in the kidneys. The study confirms the potential of Ureaplasma to form struvite stones in rat urinary tract. It also demonstrates that it can induce inflammatory changes in both bladder and kidney of rats without concomitant stone formation.

Animals↗
PubMed1989

Evaluation of cefonicid use in a general hospital.

Recently marketed drugs have limited experience in clinical use. Follow-up evaluation is therefore needed, particularly when these drugs are "restricted use" medicines, such as the second-generation cephalosporins. We present a follow-up of the first use of cefonicid, which was carried out after its substitution for cefuroxime in our hospital. The indication for use, dosing, therapeutic effects, and possible adverse reactions were recorded in 210 of the first 319 medical-surgical inpatients who received cefonicid. Cefonicid was administered to patients who could have been treated with free-use antibiotics on at least 128 occasions; these were cases of community-acquired pneumonia without any risk factor, urinary tract infections, acute exacerbations in patients with chronic lung disease, surgical prophylaxis, and intraabdominal infections. One fatal case of Stevens-Johnson syndrome was seen. Other recorded adverse events were two skin reactions, one tachyarrhythmia with evidence of low cardiac output, six episodes of phlebitis, and nine superinfections during treatment with cefonicid. The use of cefonicid instead of cefuroxime was associated with 20 percent cost savings; however, this study shows that optimal antibiotic prescribing may produce much greater savings.

Adolescent↗
PubMed1989

Human growth hormone and prolactin secreting pituitary adenomas analyzed by in situ hybridization.

Acidophilic pituitary adenomas commonly produce growth hormone (GH) or prolactin (PRL), according to studies employing immunohistochemical and ultrastructural methods. To examine this question, in situ hybridization with oligonucleotide probes was done on routinely processed tissues received in the pathology laboratory to analyze for the presence of GH and PRL messenger RNA (mRNA) in 4 normal pituitaries, 10 prolactinomas, and 16 GH-secreting adenomas. Most acidophilic cells in normal pituitaries expressed either GH or PRL hormone and the respective mRNAs, but GH mRNA and PRL hormone were also detected in some of the same cells. Patients with a clinical diagnosis of prolactinoma had cells with only PRL mRNA in their tumors, while most (14 of 16) patients with a clinical diagnosis of acromegaly or gigantism had both GH and PRL mRNAs in their tumors. The GH adenomas varied in these studies. In situ hybridization was helpful in characterizing the adenoma from a patient with acromegaly who had immunoreactive PRL, but no immunoreactive GH in the resected tumor; in situ hybridization analysis revealed mRNAs for both GH and PRL in the same tumor cells. Our findings indicate that pituitary adenomas from patients with acromegaly commonly express PRL mRNA. It is concluded that in situ hybridization provides new information about the clinical biology and the histopathologic classification of pituitary adenomas.

Adenoma↗
PubMed1989

Chromogranin A and B messenger ribonucleic acids in pituitary and other normal and neoplastic human endocrine tissues.

The distribution of the messenger ribonucleic acids (mRNAs) for chromogranin A and B was analyzed by in situ hybridization in normal and neoplastic endocrine tissues using frozen and paraffin tissue sections. Combined in situ hybridization and immunochemical staining was also done on tissue sections from the same cases using a monoclonal antibody against chromogranin A (LK2H10). Most endocrine tumors expressed chromogranin A and B mRNAs as well as chromogranin A protein. Normal pituitary expressed chromogranin A and B mRNAs and chromogranin A protein in the anterior pituitary gland. Most of these cells were gonadotropic hormone-producing cells. Prolactinomas (5/5) did not express chromogranin A mRNA or protein, but contained chromogranin B mRNA. Null cell or nonfunctional adenomas (8/8) expressed chromogranin A and B mRNAs and reacted with antibody LK2H10. In some tumors such as Merkel cell carcinomas, insulinomas, and parathyroid adenomas, a stronger signal for chromogranin A mRNA was detected than for the immunoreactive proteins. These results indicate that in situ hybridization complements immunochemical techniques in the analysis of endocrine cells and neoplasms. The gene products for chromogranin A and B are widely distributed in many endocrine cells and tumors, but some neoplasms such as prolactinomas have a differential distribution of chromogranin A and B mRNA and proteins.

Blotting, Northern↗
PubMed1988

Analysis of mammosomatotropic cells in normal and neoplastic human pituitary tissues by the reverse hemolytic plaque assay and immunocytochemistry.

The reverse hemolytic plaque assay (RHPA) was used to study hormone release from cultured normal and neoplastic human pituitary cells. The RHPA revealed a lower percentage of GH- and PRL-producing cells in normal and neoplastic pituitaries compared to the percentage of these cells revealed by immunocytochemical (ICC) staining for GH and PRL. Normal pituitary tissues as well as some PRL- or GH-producing adenomas contained large numbers of mammosomatotropic (MS) cells when analyzed by RHPA, combined RHPA-ICC, and ultrastructural immunohistochemistry with immunogold labeling. The percentage of GH and PRL cells in normal pituitaries ranged from 37-51% and 30-60%, respectively, by RHPA, while the percentage of MS cells ranged from 29-49%. The percentage of GH and PRL cells in normal pituitaries estimated by ICC ranged from 53-65% and 32-55%, respectively, while the percentage of MS cells estimated with this technique ranged from 26-50%. Double labeling with the immunogold technique detected GH and PRL in the same cells and within the same granules in both normal and neoplastic pituitary cells. These results indicate that MS cells are present in normal human pituitaries as well as in some pituitary adenomas, and in some pituitaries these two hormones are stored within the same secretory granules.

Adenoma↗