Biomedical subjects

M Remezal

Publications and source records attributed to M Remezal.

15 recordsLinked to original sources

PubMed1999

Decalcification by ascorbic acid for immuno- and affinohistochemical techniques on the inner ear.

An ascorbic acid decalcifying solution was applied to immuno- and affinohistochemical studies on the inner ear. Rat inner ears fixed in 4% paraformaldehyde in PBS or in 2% acetic acid in ethanol solutions were adequately decalcified in an ascorbic acid solution, at a temperature of 4 degrees C. The decalcifying solution was prepared with 1% ascorbic acid and 0.84% sodium chloride in distilled water (pH 2.5-2.6). The decalcification time was in a direct relationship to the specimen calcification. In this study, two neuroactive substances (gamma-aminobutyric acid and calcitonin gene-related peptide), neurofilaments, and the galectine endogenous lectin were successfully detected immunohistochemically.

Animals↗

PubMed1999

Heterotopic gastric mucosa in the upper esophagus ("inlet patch"): a rare cause of esophageal perforation.

We report the case of a 21-yr-old woman who presented with a perforation of an upper esophageal ulcer on a patch of gastric-type mucosa. Despite surgical closure of the perforation and reinforcement with a pleuro-muscular flap the patient developed an esophageal leakage and died in the postoperative period. Heterotopic gastric mucosa in the upper esophagus is usually an asymptomatic abnormality, discovered incidentally during endoscopic studies carried out for some other reason; however, complications secondary to the inlet patch acid secreting capacity can arise, and this has to be kept in mind to elude life-threatening conditions.

Adult↗

PubMed1995

[Surgical treatment of pulmonary aspergilloma].

Pulmonary aspergilloma can now be classified as an opportunistic disease given that Aspergillus tends to colonize preexisting cavities in the lung. Aspergilloma is the usual pleuropulmonary anatomical sign, hemoptysis is the most frequent symptom and a chest film is the simplest diagnostic tool. The advisability of surgery is disputed, particularly in asymptomatic patients and/or those at high surgical risk. We describe 14 patients who underwent surgery in our department, evaluating aspects of their clinical signs, diagnosis, attitude toward treatment and the course of their disease. We believe that for patients with symptomatic pulmonary aspergilloma, the treatment of choice is surgery, preferably lung resection. All patients who do not present contraindications for general surgery can be considered operable.

Adult↗

PubMed1995

Effects of indapamide on atherosclerosis development in cholesterol-fed rabbits.

We examined the effect of indapamide (IND) on the development of atherosclerosis lesions in rabbits maintained on a 1% (wt/wt) cholesterol-enriched diet for a 16-week period. IND was supplemented to the diet at three different levels to correspond to doses of 0.1, 0.3, and 1 mg/kg/day. Throughout the treatment, dietary consumption and body weight gains were comparable among the experimental and control groups. IND had no significant effect on plasma cholesterol, triglycerides, or phospholipids concentrations. Despite the lack of effect of the drug on these parameters, its administration produced a tendency toward a reduction in the aortic content of cholesterol and a dose-dependent and significant decrease in aortic damage. In the aortic arch, the extent of intimal aortic surface covered by grossly discernible atherosclerotic lesions was decreased by IND 1 mg/kg/day from 11.02 +/- 1.10 to 6.00 +/- 1.00% (p < 0.05) and from 9.72 +/- 1.39 to 5.37 +/- 1.20% (p < 0.05) in the remaining thoracic sections. In addition, the former dose also reduced the number of lesions per square centimeter from 3.69 +/- 0.68 to 1.72 +/- 0.53% (p < 0.05), and from 3.37 +/- 0.85 to 1.55 +/- 0.46% (p < 0.05) in aortic arch and in thoracic sections, respectively. The possibility that IND reduces the development of atherosclerotic lesions produced by diet-induced hypercholesterolemia through a mechanism involving its calcium antagonist and/or its antioxidant activity is discussed.

Administration, Oral↗

PubMed1995

[Appendiceal Crohn's disease].

Crohn's disease of the appendix is an uncommon process that is more frequent in young people. The most common preoperative diagnosis is acute appendicitis. At exploratory laparotomy the appendix is enlarged and malignancy may be suspected. The differential diagnosis may be difficult. Serologic tests and cultures should be performed to exclude Yersinia infections. Appendicectomy is a safe procedure when the disease is limited to the appendix. The postoperative course is usually uncomplicated with a low rate of complications and recurrence. Although it may be a different process than Crohn's disease and the recurrence rate is low, it is suggested that all the patients should be followed-up so that recurrences may be recognized and treated as early as possible. A new case is presented after two years of follow-up without recurrence.

Abscess↗

PubMed1995

[Leiomyosarcoma within a bladder diverticulum].

Sarcomas are a rare entity among malignant tumours of the bladder. This paper presents the case of a male patient with leiomyosarcoma within a vesical diverticulum. The approach undertaken was diverticulectomy and, since the tumour was limited to the diverticulum and no metastatic disease was present, no other adjuvant therapy was considered.

Aged↗

PubMed1994

H and B human blood-group antigen expression in cochlear hair cells is modulated by thyroxine.

The presence of human blood-group antigens in developing and adult hypothyroid rat cochleas was analyzed using antibodies directed against antigens H and B. During postnatal development, hypothyroid rat cochleas exhibited a highly selective expression of both B and H antigens, mainly at the hair cell level. Labeling for antigen B was found throughout the hair cells, whereas the antibody directed against antigen H selectively labeled the apical part of these cells. These immunostaining patterns were similar to those found in normal (euthyroid) rat cochleas, but antigenic expression periods were clearly prolonged. Thus, whereas in normal rat cochleas, the B and H antigenic expression disappears from postnatal day (PD) 9 on, in cochleas of hypothyroid rats the reactivity was intense until PD15; it decreased from this developmental stage, and was negative or only faintly positive at PD30. Therefore, in congenital hypothyroidism, hair cell immunoreactivity is present at developmental stages that are negative in normal rat cochleas. These results suggest that human blood-group antigen expression on the developing cochlear hair cells of rats is modulated by thyroxine and that thyroxine is necessary for the temporal expression pattern and secretion of normal glycoproteins.

ABO Blood-Group System↗

PubMed1994

[Colangiocarcinoma on a choledochal cyst].

Patients with choledochal cysts have an increased incidence of biliary tract carcinoma. We report a case of adenocarcinoma arising in a type I choledochal cyst which was surgically treated by resection and biliodigestive anastomosis (hepaticojejunostomy).

Adenocarcinoma↗

PubMed1993

Effects of noise stimulation on cochlear dopamine metabolism.

Dopamine (DA) appears to be one of the putative neurotransmitters of the lateral efferent olivocochlear fibers. However, its role in the cochlear physiology remains unknown. In this study, animals were exposed for 1 h to white noise at 70, 90 or 110 dB SPL or were kept in silence conditions. Afterwards, the cochlear content of DA and its metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were analyzed using HPLC coupled to electrochemical detection. Cochlear DA concentration decreased with the noise intensity, while cochlear DOPAC and HVA concentrations increased. Males presented higher cochlear DOPAC contents and lower HVA contents than females. This sexual dimorphism could be related to the link between DA and gonadal steroids. Present results show that DA, as other lateral efferent neurotransmitters, is released and metabolized in relationship with the noise stimulation, and suggest that DA could be involved in the modulation of the type I afferent fiber activity.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1993

Histochemical localization of a beta-galactoside-binding lectin and its binding-sites in developing and adult rat cochlea.

The presence of an endogenous rat beta-galactoside-specific lectin (S-Lac) and its specific binding ligands was analyzed, using a rabbit anti-human brain lectin of 14 kDa antibody (anti-HBL-14) and a probe consisting of a biotinylated derivative of the human lectin (HBL-biot) in adult and in developing rat cochleas. At PD1, some epithelial cells of the outer spiral sulcus (OSS) were specifically recognized by the anti-HBL-14 antibody. Then, anti-HBL-14 immunoreactivity progressively appeared in all OSS epithelial cells, and, from PD9 on, it also appeared in inner spiral sulcus (ISS) epithelial cells. Finally, young adult rats exhibited a well defined anti-HBL-14 immunoreactivity in epithelial cells of the inner and outer spiral sulcus. Using the biotinylated probe, from PD3 on, tectorial membrane (TM) and the sensory cells apical surfaces were labelled. The glycoconjugate expression within the developing organ of Corti seems to be highly complex. Lectin was detected in developing and adult epithelial cells surrounding the organ of Corti. In contrast, other glycoconjugates related to B and H human blood group antigens, were transiently present on sensory cells of the organ of Corti. Present findings can be correlated with significant events in development of the cochlea, mainly with cell-cell recognition or cellular adhesion.

Animals↗

PubMed1993

Immunocytochemical approach to the structure of human blood group B and H glycoconjugate antigens in the three days old rat cochlea.

The possible structure of human blood-group antigens, as found in cochlear hair cells of 3-day-old rats, is suggested. Data were obtained from immunocytochemical studies using 77 antibodies against the major human blood group antigens of the ABO, H, I and Lewis genetic systems. Neither the anti-A-related nor the anti-Lewis-related antibodies showed any positive immunoreaction on hair cells. In contrast, anti-B, anti-AB and anti-H antibodies displayed specific positive immunoreactive patterns on the hair cells. The results suggest that, in immature hair cells, two main glycoconjugate structures of the lactoseries are present: H type 2 antigen, which is the precursor of the B type 2 antigen, and the B type 2 antigen itself. Similar H and B carbohydrate structures have been reported in rat olfactory receptors. The type 2 glycoconjugates carrying these H and B antigens of auditive and olfactory receptors are resistant to fixation and paraffin embedding, suggesting that they might be glycoproteins. These auditive and olfactory H and B antigens must be different from the B-related antigens that are expressed by pseudo-unipolar neurons of rat posterior root ganglia, that are built from type 4 core chains, and that are destroyed by routine paraffin embedding procedures.

ABO Blood-Group System↗

PubMed1993

Incorporation of D3H glucosamine to the adult and developing cochlear tectorial membrane of normal and hypothyroid rats.

The uptake of D-3H-glucosamine by the developing cochlea of normal and hypothyroid rats was examined using light microscopic radioautography. During postnatal development, normal and hypothyroid rat cochleas exhibited a layer of radiolabelling in the tectorial membrane (TM). This layer first appeared in the TM region which covers the spiral limbus and the Kölliker's organ (KO), then progressively reached the apical part of the TM covering the organ of Corti. Radiolabelling was significantly greater in hypothyroid than in normal cochleas. These findings suggests that the enormous size reached by the TM in the congenital hypothyroidism could be related to an increase of epithelial secretion, at least for carbohydrates. It also suggests that TM, in normal and hypothyroid cochleas, could be formed during development by the addition of successive layers. Older layers could be displaced upwards by the new ones. Cochleas of normal young adult rats, treated with D-3H-glucosamine, showed a very scarce and diffuse radiolabelling. Cochleas of hypothyroid young adult rats exhibited a thickened and distorted TM, which incorporated a significant amount of carbohydrates. These results suggest that TM secretion is highly reduced in young adult normal animals, while in young adult hypothyroid ones it is still active. During cochlear maturation, thyroxine seems to be necessary, not only for the synthesis of normal glycoproteins (as suggested by previous reports), but also for the control of glycoprotein secretion.

Animals↗

PubMed1992

Neuronal influence on B and H human blood-group antigen expression in rat cochlear cultures.

The presence of B and H human blood-group antigens was analyzed by immunocytochemistry in rat cochleas developing either in vivo or in vitro. Developing animals, on embryonic day (E) 18 and postnatal day (P) 3, were used for in vivo studies. For in vitro studies, cochleas were removed at E18 and placed for 3 or 8 days in organotypic culture either directly or after partial spiral ganglion removal. Results from epithelial regions from cochleas developing in vivo were similar to those observed in corresponding areas of direct organotypic cultures where the innervation from spiral ganglion neurons was present. Antibodies to human blood group antigens, anti B and anti AB, selectively labeled hair cells. The intensity of labeling was weak at E18, but increased at P3 in vivo or after 3-8 days in organotypic culture. Anti H antibodies showed weak labeling of the apical surface of hair cells and other epithelial cells at E18; this labeling also increased at P3 or after 3-8 days in culture. In contrast, the non-innervated regions from organotypic cultures, where ganglia were partially removed, exhibited an epithelial disorganization and no hair cell labeling with any of the antibodies studied. The present findings suggest that human blood-group antigen expression on developing cochlear hair cells of rats may be related to afferent nerve fiber influence.

ABO Blood-Group System↗

PubMed1991

Incorporation of D-[3H]-glucosamine and L-[3H]-fucose into the developing rat cochlea.

The uptake of two tritiated carbohydrates, D-[3H]-glucosamine and L-[3H]-fucose, to the developing rat cochlea was examined using light and electron microscopic radioautography. Both carbohydrates, administered to in vitro developing rat cochleas, shared a similar ultrastructural labeling pattern on the microvilli and apical cell region and on the tectorial membrane (TM) fibrils. On embryonic day 18, the radiolabeling appeared on the apical surface of the undifferentiated epithelium that will develop into both spiral limbus and Kölliker's organ (KO), while on postnatal day (PD) 1, it was only located on the apical surface of the KO. When D-[3H]-glucosamine was administered in vivo to newborn rats, the radiolabeling was observed in the TM covering the KO at PD 3. Lastly, D-[3H]-glucosamine administered in vivo to PD 7 rats, appeared at PD 9 in the TM region lying just above the organ of Corti. The present findings support the previously suggested leading role of the spiral limbus and KO in the secretion of the TM during cochlear development. The secretion of carbohydrates, and probably of other matrix components, starts on the spiral limbus and KO region and progressively extends to the organ of Corti.

Animals↗

PubMedDate not supplied

Ultrastructural localization of H human-blood-group immunoreactivity rat cochlear hair cells.

Human blood-group antigens are transiently expressed in developing cochlear hair cells. This temporal antigen expression seems to correspond to the main events of inner ear differentiation (e.g. hair cell development, synaptogenesis, ciliogenesis). In the present report, the cochlear expression of H human blood group antigen has been analyzed with the aid of the electron microscope. Ultrastructurally, cochleas stained with anti-H antibody exhibited an intense immunoreactivity on the apical hair cell membrane and on stereocilia. Cell surface glycoconjugates may serve a large number of functions and could be important during cell development. The temporal expression of H blood-group antigen in developing cochlear hair cells could be related to stereocilia differentiation.

ABO Blood-Group System↗