[Cavitated pulmonary mass in a 19-year-old male].
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Abscess↗
Biomedical subjects
J Ramírez
Publications and source records attributed to J Ramírez.
An energy-dependent efflux system for potassium ions in yeast.
An efflux of potassium ions was demonstrated in mutants of yeast cells lacking a functional high affinity carrier system for monovalent cations. This efflux showed the following characteristics: (a) It was stimulated by the presence of a substrate, either glucose or ethanol. (b) It was stimulated by several cationic organic molecules, such as ethidium bromide, dihydrostreptomycin, diethylaminoethyldextran, and also by trivalent cations, such as Al3+ and lanthanides; this stimulation also depended on the presence of a substrate. (c) K+ efflux was decreased in yeast mutants with decreased ATPase activity, which generated a lower membrane potential. (d) Although the efflux appeared to be of an electrogenic nature, producing hyperpolarization of cells, it was accompanied by the efflux of phosphate, probably as an anion partially compensating for the large amount of cations leaving the cell. (e) K+ efflux was also accompanied by an uptake of protons. (f) The efflux appeared more clearly in cells grown in YPD medium, and not in more complex media nor in the same YPD medium if supplemented with Ca2+ or Mg2+. Efflux of monovalent cations produced by Tb3+ and organic cationic agents was also demonstrated in wild type strains. This efflux system appears to be, at least partially, electrogenic, but seems to be also an exchange system for protons and to function as a symport with phosphate; it may be involved in the regulation of the internal pH of the cell, and appears to be regulated by its link to the energetic status of the cell, probably through the membrane potential.
Calcium↗
[Round atelectasis: infrequent cause of solitary pulmonary nodule].
Two cases of round atelectasis are reported. One had an asbestiform origin, with lingular localization and pathological confirmation. The other was located in the posterobasal segment of the left lower lobe, and it was presumably caused by pleural tuberculosis. In both patients the characteristic radiological findings were present, with an outstanding "comet's tail" sing. The outcome of both patients was satisfactory. Emphasis is made on the usefulness of noninvasive diagnostic investigations, such as conventional pulmonary and computed tomography (CT) of the torax, which, in conjunction with an adequate anamnesis, permit the correct diagnosis and may prevent surgical exploration.
Aged↗
Calcium transport sensitive to ruthenium red in cytochrome oxidase vesicles reconstituted with mitochondrial proteins.
We describe a calcium transport that is sensitive to ruthenium red in liposomes reconstituted with mitochondrial extracts. This system is able to build an internally negative membrane potential, which allows the electrogenic influx of Ca2+ and Sr2+. Proteins with molecular weights higher than 35 kDa were incorporated to the vesicles, and enhanced the accumulation of the cation in an energy-dependent fashion.
Animals↗
Liposomes as carriers for allergy immunotherapy.
With the aim of obtaining an efficient but safer vaccine for allergy immunotherapy, the possibility of using liposomes as adjuvants has been considered given their proven low toxicity, adjuvant properties and ability to maintain the encapsulated substance in their interior for some time in vivo. Different methods of encapsulating allergenic extracts into neutral, positively, and negatively charged DPPC: cholesterol liposomes have been investigated and the immune response provoked by these in mice was studied and compared to the immune response to free allergen or other adjuvants such as aluminium hydroxide. The results obtained show that allergen encapsulated in all three types of liposomes elicit an increase in specific IgG levels higher than that provoked by free allergen, however, both encapsulation efficiency and specific IgG titre were higher when positively charged (DPPC: cholesterol stearylamine) liposomes were used. Specific IgE levels to allergen in positive and neutral liposomes was lower than to allergen in negative liposomes or adsorbed to Al(OH)3. No difference were found in the behaviour of liposomes prepared by different methods (the results were obtained from pooled sera from different groups of mice so there is no statistical data). These results confirm the immunoadjuvant effect of liposomes for allergy immunotherapy. Further studies to determine their lack of toxicity, pharmacokinetic studies and human clinical studies are necessary to confirm their adequacy for human use and advantage over current immunotherapy methods.
Allergens↗
[Round table. Cervix uteri neoplasms].
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Colposcopy↗
[Disseminated mucormycosis in a hemodialyzed female patient treated with deferoxamine].
A case is presented of a patient affected of chronic renal failure caused by multiple myeloma who was under a chelating treatment with Depreroxamine as a consequence of iron intoxication and suffered a disseminated mucormycosis. We performed a literature search of previous cases and discuss the probable relation between this opportunistic infection and depheroxamine treatment.
Deferoxamine↗
Cholesterol side-chain cleavage and 11 beta-hydroxylation are inhibited by gossypol in adrenal cortex mitochondria.
Cholesterol side-chain cleavage and 11 beta-hydroxylation were assessed in isolated adrenal cortex mitochondria by formation of pregnenolone and corticosterone, respectively, in the presence and absence of gossypol. Pregnenolone biosynthesis was inhibited when increasing concentrations of gossypol were added. The control value of 4 nmol min-1 mg-1 dropped to 2 nmol min-1 mg-1 with 30 microM of the drug in the incubation medium. A more pronounced inhibitory effect was observed upon 11 beta-hydroxylation of steroids; I50 was 11 microM. Seventy-five percent of corticosterone production was impaired when 30 microM of gossypol were present. Bovine serum albumin prevented and reversed the inhibitory action of the drug. Kinetic studies showed a linear mixed type inhibition, suggesting a direct action of the drug upon the enzymatic complex. This study demonstrates a direct inhibitory effect of gossypol upon the steroidogenic enzymes located in the inner mitochondrial membrane of the adrenal cortex.
Adrenal Cortex↗
Experimental reconstruction of the canine trachea with a free revascularized small bowel graft.
Extensive tracheal stenotic lesions caused by tracheomalacia or neoplasms represent a surgical challenge. Segmental tracheal substitution is sometimes required to obtain radical cure. We present an experimental study of 27 dogs undergoing replacement of the cervical trachea using a vascularized small bowel segment as a tubular graft. A silicone stent was placed in the lumen of the intestinal fragment and was removed the second week after operation. Endoscopic and histological examinations were performed between the first week and second month after operation, and rigidity of the graft was assessed in all cases. No evidence of anastomotic stricture or mucous formation was found. Microscopic examination showed the substitution of bowel mucosa by squamous epithelium as well as the development of connective tissue favoring the fixation of the skeletal muscular structures of the neck to the serous layer of the graft, thus avoiding collapse of the new airway.
Anastomosis, Surgical↗
Histological types of laryngotracheal tumors induced in Syrian golden hamsters by nitrosomorpholine and nitrosopiperidine.
The chronic oral administration of nitrosomorpholine (NM) and nitrosopiperidine (NP) to 360 adult Syrian golden hamsters of both sexes resulted in the induction of a high incidence of laryngo-tracheal tumors, which in the group treated with 0.01% solution of NM affected up to 80% of the males. A total of 232 different laryngo-tracheal tumors were found. 36 of these were located within the supraglottic and glottic larynx, 62 were within the subglottic and glottic larynx, and 134 arose within the trachea. Among the laryngeal supraglottic and glottic tumors there were 18 squamous cell carcinomas, 16 squamous cell papillomas and only 2 mixed cell mucoepidermoid papillomas. All the subglottic laryngeal tumors and tracheal tumors were mixed cell mucoepidermoid papillomas. In this study, the squamous cell carcinomas observed within the larynx of hamsters bear morphological and biological similarities to their tumor counterpart found in the larynx of adult man. The laryngeal squamous papillomas observed in this experiment are not similar to the squamous papillomas occurring in man during infancy and childhood. The mixed cell mucoepidermoid papillomas of the hamster trachea and subglottis are a peculiar neoplasm of this species, which morphologically and biologically differs from the cases of tracheal papillomatosis described in man, as well as from the mucoepidermoid tumors of major and minor salivary gland origin also seen in this latter species.
Administration, Oral↗
Primary intrapulmonary benign schwannoma. A case with ultrastructural and immunohistochemical confirmation.
Neurogenic pulmonary tumours are rare. Neurofibromas are the most common variety and tend to occur in patients with generalized neurofibromatosis, whereas schwannomas arise sporadically in patients who have no evidence of this disorder. A case of solitary benign schwannoma arising in a segmental bronchus is presented, and the published cases reviewed. Microscopically, the tumour had a spindle-shaped cell proliferation with palisade formation in several fields and low cellularity in other areas. The diagnosis was supported by positive immunostaining for S-100 protein and by ultrastructural examination which showed elongated cells surrounded by well-preserved basal lamina and numerous cytoplasmic processes also possessing a basal lamina.
Aged↗
Acute pulmonary histoplasmosis: newly recognized hazard of marijuana plant hunters.
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Adult↗
Aurovertin fluorescence changes of the mitochondrial F1-ATPase during multi- and uni-site ATP hydrolysis.
The aurovertin-F1 complex was used to monitor fluorescence changes of the mitochondrial adenosine triphosphatase during multi- and uni-site ATP hydrolysis. It is known that the fluorescence intensity of the complex is partially quenched by addition of ATP or Mg2+ and enhanced by ADP (Chang, T., and Penefsky, H. S. (1973) J. Biol. Chem. 248, 2746-2754). In the present study low concentrations of ATP (0.03 mM) induced a marked fluorescence quenching which was followed by a fast fluorescence recovery. This recovery could be prevented by EDTA or an ATP regenerating system. The rate of ATP hydrolysis by the aurovertin-F1 complex and the reversal of the ATP-induced fluorescence quenching were determined in these various conditions. ITP hydrolysis also resulted in fluorescence quenching that was followed by a recovery of fluorescence intensity. Under conditions for single site catalysis, fluorescence quenching was observed upon the addition of ATP. This strongly indicates that fluorescence changes in the aurovertin-F1 complex are due to the binding and hydrolysis of ATP at a catalytic site. Therefore the resulting ADP molecule bound at this catalytic site possibly induces the fluorescence recovery observed.
Adenosine Diphosphate↗
Measurement of casein digestion by a fluorometric method.
A qualitative and quantitative method to assay proteolytic degradation of casein with a spectrofluorometer was developed. Proteolysis produced by different pure or mixed proteinases in a pH range 2 to 7.4 quenches the fluorescence emitted at a wavelength of 350 nm by casein excited at 300 nm in less than 5 min. This method is very sensitive, fast, and requires minimal sample preparation. Proteinases that do not generate peptides appropriate for fluorescence quenching cannot be detected with this assay and proteinases with intrinsic fluorescence may require special adjustments of the spectrofluorometer. This method monitors the disappearance of intact substrate proteins continuously, omitting the separation step necessary in other methods to measure product peptides.
Animals↗
[Dyspnea, chest pain and respiratory insufficiency in a 68-year-old man].
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Aged↗
Mutagenicity of urine from mice exposed orally to nitrite and various aminated antiparasitic drugs.
Mutagenic N-nitroso compound formation from the in vitro reaction of amebicides and anthelmintic drugs, which are pyrimidine derivatives or contain secondary aliphatic amines or heterocyclic nitrogens, has been previously described (Arriaga Alba et al.: Environmental and Molecular Mutagenesis 12:65-73, 1988). Under similar conditions, antiparasitic drugs containing halogenated derivatives of tertiary amines or quaternary ammonium salts do not form mutagenic nitrosated compounds. In the present study the mutagenic activity of mouse urine was determined after oral administration of sodium nitrite and the two above-mentioned groups of drugs (pyrantel pamoate, chloroquine, piperazine and dehydroemetine/iodochlorhydroxyquin and bephenium hydroxynaphthoate, respectively). Results show that the simultaneous administration of piperazine or chloroquine with sodium nitrite produced urinary mutagens that appeared conjugated as glucuronides, whereas pyrantel pamoate and dehydroemetine in the presence of nitrite caused only slightly mutagenic urine. No mutagenic activity was detected in the urine of mice to which halogenated derivatives of tertiary amines (iodochlorhydroxyquin) or quaternary ammonium salts (bephenium hydroxynaphthoate) were administered together with nitrite.
Amebicides↗
New design for fixation of surgically obtained lung specimens.
A new design for lung fixation at a constant transpulmonary pressure is described. The head pressure of the apparatus can easily be set in a range from 15 to 95 cm H2O and maintained at a constant level through the recirculation of the fixative fluid. Moreover, the dimensions of the device are smaller than those previously reported. To analyze the efficiency of the equipment the estimated total post-fixing lung volume (TLV) in 12 surgically obtained lung specimens was calculated and compared with helium single-breath total lung capacity measurements (TLCsb). The TLV/TLCsb ratio was 102 +/- 5%. In addition, TLV was related to predicted TLC values (TLCpred) from different reference equations. The TLV/TLCpred ratios ranged from 89 to 99%. Estimated volumes of formalin fixed lungs did not show significant differences to those obtained by TLCsb measurements (p = 0.49). Consequently, it can be concluded that the fixation procedure performed with this device does not produce changes in air space dimensions of surgically obtained lung specimens. Moreover, the variability in TLV/TLC ratios depends upon either the technique of TLC measurement or the set of predicted values used.
Adult↗