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Biomedical subjects

M M Ruchoux

Publications and source records attributed to M M Ruchoux.

At least 73 records · Page 4Linked to original sources
PubMed1992

Ultrastructural study of the choroid plexus of spontaneously hypertensive rats.

We previously gave an account of an increased ion transport activity in choroid plexus from spontaneously hypertensive rats. We have since examined this organ in scanning and transmission electronic microscopy. In the choroid plexus from young spontaneously hypertensive rats, the epithelial cells showed the following: a partial loss of the brush border and infoldings of basolateral membranes, an increased number of Golgi apparatus, vesicles, and mitochondria, and an activated nucleus. In adult hypertensive rats, the mitochondria had increased in number and tended to fill the cytoplasma while the nuclei had returned to a resting level. These ultrastructural changes furthermore suggest an increased secretory activity in the choroid plexus in spontaneously hypertensive rats.

Aging↗
PubMed1992

Acute measles encephalitis of the delayed type: neuroradiological and immunological findings.

A case of delayed acute measles encephalitis in an immunosuppressed child is reported. Detailed immunological studies have shown defective humoral immunity (defective IgA, IgG2 and IgG3) and decreased natural killer activity. Neuroradiological examination by magnetic resonance imaging revealed several high signal lesions on T2-weighted images in the gray matter without clinical or pathological correlation. The implications of these findings are discussed.

Antigens, Viral↗
PubMed1992

Lhermitte-duclos disease. A rare cause of intracranial hypertension in adults.

In a 39-year old woman hospitalized for intracranial hypertension MRI revealed the presence of abnormal areas in the cerebellar cortex. The negative results of investigations for possible causes, as well as the appearance of radiological abnormalities and their persistence over a 6-month period incited the authors to make a tentative diagnosis of Lhermitte-Duclos disease, despite the lack of anatomicopathological evidence.

Adult↗
PubMed1990

Cicletanine and hypertensive retinopathy.

The aim of the present work was to study the activity of a new antihypertensive drug, a synthetic furopyridine, cicletanine, upon hypertensive morphological lesions of the retina. The stroke-prone spontaneously hypertensive rat strain (SHR-SP), known to develop hypertensive retinopathy, was a particularly suitable material in this view. The experiment was carried out in 39 rats (SHR-SP/A3N Iffa Credo), initially at the age of 11 weeks, divided into 3 groups: one as control group, the other two treated orally with 100 and 150 mg/kg cicletanine, respectively. All rats had free access to tap water containing 1% NaCl. For 46 days, blood pressure, body weight and death rate were recorded, then the rats were sacrificed. The eyes were removed, the posterior pole collected and fixed with Trump's liquid for transmission electron microscopy. In the control group, the capillaries showed marked hypertensive lesions. Multivesicular bodies were found in the different layers, particularly in the innermost layers; photoreceptor impairments could also be observed. In contrast to this group, both cicletanine-treated groups showed only rare and minimal lesions.

Administration, Oral↗
PubMed1989

The effect of cicletanine on cerebrovascular injury in stroke-prone spontaneously hypertensive rats.

The stroke-prone spontaneously hypertensive rat (SHR-SP) is one of the most suitable models for stroke study. The present trial work was undertaken so as to obtain further information concerning the action of a new furopyridine, cicletanine. Forty-six males--SHR-SP/Iffa Credo rats--aged 7 weeks, were divided into three groups. Group 1 was a control group, groups 2 and 3 were orally treated with cicletanine at 30 and 100 mg/kg. Their drinking water contained 1% NaCl. Systolic blood pressure, body weight, and survival were recorded. After 6 weeks, all the rats were sacrificed. Samples of heart, brain, and kidney were fixed for light and ultrastructural examination. We found that cicletanine treatment (30 and 100 mg/kg) had significantly inhibited the incidence of hypertensive cerebral damages as characterized by cerebral infarction and vascular alterations with fibrinoid necrosis. Compared with the control group, the rats treated with the cicletanine had a significantly increased survival rate (P less than .001); the cicletanine also had an important protective effect on tissue. Cicletanine administration prevented the development of hypertensive cerebral vascular damage, probably through direct action on the vascular walls.

Animals↗
PubMed1989

A mechanical stress increases sodium ion content in vascular smooth muscle cells through a calcium-dependent pathway: prevention by cicletanine via a cyclo-oxygenase product.

The non-laminar (rather turbulent) flow induced by cell washings was able to reversibly increase the sodium ion (Na+) content in cultured A10 aortic smooth muscle cells. Similar changes, although to a lesser extent, were observed in cardiocytes but not in fibroblasts, erythrocytes, thymocytes or macrophages, suggesting that the changes are specific to excitable cells. The increase in vascular sodium content had the following properties: (1) It was inhibited by nitrendipine; (2) it was accompanied by an increase in the free cytosolic Ca2+ content; (3) it was unable to stimulate the sodium pump; and (4) it reflected the qualitative and quantitative composition of the incubation media. These observations suggested that a non-laminar flow is able to open potential-dependent calcium channels, with secondary internalization of high amounts of extracellular ions. These ionic perturbations were blocked by low concentrations of cicletanine; the half-maximal inhibitory concentration (IC50) was about 10(-9) mol/l on internal sodium. The protective effects of cicletanine were inhibited by indomethacin, suggesting that they are mediated by a cyclooxygenase metabolite, perhaps prostacyclin. Captopril and diuretic drugs such as hydrochlorothiazide, furosemide, spironolactone or acetazolamide were unable to protect vascular cells against the harmful effects of cell washings.

Animals↗
PubMed1989

Ectopic prolactinoma within the sphenoid sinus.

A case of an ectopic prolactin-producing tumor located within the sphenoid sinus is reported. It was discovered in a girl who experienced secondary amenorrhea without galactorrhea. We discuss the different diagnoses proposed before immunocytochemical staining results were available. This case presented unusual radiological, surgical, and histopathological aspects.

Adolescent↗
PubMed1989

[Protective action of cicletanine on the vascular walls in stroke-prone spontaneously hypertensive rats].

UNLABELLED: In previous works, cicletanine has proven a protective effect on tissues in stroke-prone spontaneously hypertensive rats. The mechanism by which cicletanine lessens the tissue lesion incidence may be explained by the direct vascular effect of increased prostacyclin synthesis and by interaction with various agents mobilizing intracellular. Ca2+ ions. Histological so as to ultrastructural studies of the capillaries and small arteries were performed, specially on those of brain, kidney, heart, and choroid. Method : 36 SHR-SP/A 3N Iffa Credo rats aged 11 weeks were divided into 3 groups. Their drinking water was added with 1 p. 100 NaCl in. Group I was a control group, groups II and III were orally treated with cicletanine, respectively 100 and 150 mg/Kg. Systolic blood pressure, body weight, survival were reported. After 7 weeks of treatment the surviving rats were sacrificed. RESULTS: the control group arterioles showed endoluminal debris with intimal proliferation and a large disorganisation of the media with adventitial fibrosis. The treated groups only showed a slight oedema of the subendothelial space in ultrastructure with no intimal proliferation and no muscle coat disorganisation or proliferation. CONCLUSION: even though the decrease in blood pressure turned out to be very unimportant, the amount of lesions in vessels was striking even when treatment had been started on a already high blood pressure. The vessel walls only presented the impairments usually observed in early arterial response to hypertension. This study shows that cicletanine, due to its properties to increase PG12 synthesis and counterbalance the increase of cytosolic free Ca2+, improves the normal course of hypertensive vascular lesions in the SHR-SP.

Animals↗
PubMed1989

[Malignant hypertensive retinopathy in spontaneously hypertensive stroke-prone rats. Effect of treatment with cicletanine].

Stroke-Prone spontaneously hypertensive rat strain (SHR-SP) always develops hypertensive retinopathy. The aim of the present work was to study the activity of a new antihypertensive drug, a synthetic furopyridine: cicletanine, in retinal hypertensive morphological lesions. The experiment was performed in 39 rats SHR-SP/A3N Iffa Credo, 11 weeks old, divided into 3 groups: group 1 was the control group, groups 2 and 3 were orally treated with cicletanine (respectively 100 and 150 mg/kg). All the rats had free access to tap water containing 1 p. 100 NaCl. During 6 weeks, blood pressure, body weight and survival were recorded, then all the rats were sacrificed. The eyes were removed, the posterior pole collected and fixed with Trump liquid for transmission election microscopy. In the SHR-SP control group, each layer showed neural body and/or process lesions: in the ganglion cell layer, some ganglion cells realized cytoid bodies corresponding to a lysed cell with nucleus degeneration, most of the axons were destroyed. In the inner and outer plexiform layers, most of the contacts between processes were lost because of fibrinous deposits. Numerous synapses were destroyed in the outer plexiform layer. These findings might explain the numerous dense bodies in the inner rod segment and the vesiculation of the rod outer segment. The capillaries showed markedly hypertensive lesions. Whereas, in both treated groups, rare and animal lesions were observed. The fact that these lesions were so few and so unimportant after 6 weeks of treatment, as well as for the photoreceptors which remained unimpaired, is closely related to cicletanine therapy, since it was so even though the treatment had been started with an already high blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Effectiveness of cicletanine on lesions in spontaneously hypertensive rats. Curative study--dose-effect relationship].

Genetically hypertensive rats receiving a high sodium content diet develop, within weeks of their birth, major alterations of tissues and blood vessels. The purpose of this study was to evaluate the effects of cicletanine, a synthetic antihypertensive drug, on the progress of genetic hypertension. Iffa Credo SHR-SP male rats aged 11 weeks were divided into 4 groups. One group was used as control and 3 groups were treated with oral cicletanine in doses of 10, 30 and 90 mg/kg/day respectively. The control group showed a high mortality rate due to a significant decrease of weight gain and a highly significant increase of blood pressure, these changes being associated with lesions of tissues and vessels in the brain, heart and kidneys. A curative treatment with cicletanine improved these parameters and was accompanied by good tissue preservation. The curative effect of cicletanine seems to be due to an increase in endogenous prostaglandin synthesis.

Animals↗
PubMed1989

[Comparison of the effects of cicletanine and captopril on kidney and heart lesions in spontaneously hypertensive rats (SHR-SP)].

All studies carried out on stroke-prone spontaneously hypertensive rats (SHR-SP) have clearly demonstrated that cicletanine protects tissues and vessels. This effect has also been observed with captopril. However, the effectiveness of captopril seemed to be dependent on its blood pressure lowering effect, and this was not found with cicletanine in previous experimental studies on SHR-SP. In view of the difference in effectiveness between captopril and cicletanine as regards blood pressure, it was considered important to compare the two compounds in a similar blood pressure complex. In this study, the effects of cicletanine at two dosage levels (3.33 and 10 mg/kg/day) on the tissue and vascular lesions of SHR-SP were compared with those of captopril in doses of 1 mg/kg/day. Iffa Credo SHR-SP rats aged 7 weeks were divided into four groups of 12 animals each: 2 groups received cicletanine 3.33 and 10 mg/kg/day respectively, 1 group received captopril 1 mg/kg/day and 1 group served as control. Blood pressure was recorded once a week. After 44 days of treatment, all animals were killed and autopsied. A significant antihypertensive effect was observed with both captopril (p less than 0.001) and cicletanine 10 mg/kg (p less than 0.05). In doses of 3.33 mg/kg cicletanine induced only a very slight fall in blood pressure, not significantly different from controls. On the other hand, histological and ultrastructural examinations showed better preservation of tissues and, chiefly, vessels with cicletanine at the two dosage levels than with captopril 1 mg/kg.

Animals↗
PubMed1989

[Effects of cicletanine on kidney lesions associated with age. Light and electron microscopy studies].

Aging laboratory animals constantly present with chronic progressive nephrosis. The purpose of this study was to investigate the protective effect of a chronic treatment with cicletanine in aging rats, notably as regards kidneys. Sixteen Wistar rats aged 26 months were divided into two groups: one group served as control, while the other received oral cicletanine 30 mg/kg/day. Blood pressure, weight and death rate were recorded. No rise of arterial pressure was observed in either group. The rats were killed on day 151, i.e. aged 31 months, after 5 months of treatment. All were autopsied and their kidneys, heart, lungs, liver, brain and eyes were removed for examination. Light microscopy of the renal tissue showed the lesions described in the chronic progressive nephrosis of the aging rat. These lesions were diffuse and pronounced in the control group and minimal in treated rats. The difference was confirmed by electron microscopy. The basal membrane of renal tubules was slightly thickened in the treated rats and two or three times thicker in control rats. Mitochondrial alterations were observed in the proximal tubules of controls but not in those of rats treated with cicletanine. Thus, after a 5-months treatment with cicletanine aging Wistar rats well known for their renal pathology were protected against kidney lesions in contrast with untreated rats.

Aging↗
PubMed1989

[Ionic perturbations produced by a non-laminar flow in vascular smooth muscle cells in culture. Protection by cicletanine via a cyclo-oxygenase metabolite].

The non-laminar (rather turbulent) flow, induced by cell washings was able to reversibly increase internal Na+ contents in cultured aortic smooth muscle (A10 cells). Similar changes (although to a lesser extent) were observed in cardiocytes but not in fibroblasts, erythrocytes, thymocytes or macrophages, suggesting that they are specific for excitable cells. The increased vascular sodium content had the following properties: it was inhibited by nitrendipine; it was accompanied by an increase in free cytosolic Ca2 contents; it was unable to stimulate the sodium pump and (iv) it reflected the qualitative and quantitative composition of the incubation media. These observations suggested to us that the increased vascular sodium content results from the opening of potential-dependent calcium channels with secondary internalisation of high amounts of extracellular ions. The ionic perturbations were blocked by low concentrations of cicletanine (IC50 of about 10(-9) M on intracellular sodium). Moreover, the protective effects of cicletanine were inhibited by indomethacin, suggesting that they are mediated by a cyclo-oxygenase metabolite, perhaps prostacyclin. Sodium nitroprusside, a compound able to stimulate calcium entry in the sarcoplasmic reticulum via cyclic GMP, was also able to protect vascular cells (although it acted at higher concentrations than cicletanine). Conversely, captopril and diuretic drugs such as hydrochlorothiazide, furosemide, spironolactone and acetazolamide were unable to protect vascular cells against the deleterious effects of cell washings.

Antihypertensive Agents↗
PubMed1989

[Prostatic type papillary tumor of the urethra with endocrine cells. Immunohistochemical study].

A peculiar variety of prostatic neoplasm harbouring a constellation of endocrine cells is reported. The tumor had a papillary growth projecting into the lumen of the prostatic urethra. The histological appearances were somewhat unusual. One fragment showed a typical feature of a prostatic-type polyp. However, much of the tissue were covered by a dysplastic epithelium. Adenomatous transformation of prostate-type polyp or "endometrial" adenocarcinoma could be considered.

APUD Cells↗
PubMed1989

[Epidermoid cyst of the iris].

Epidermoid cyst of the iris is a primary cysts of the iris, and more precisely a congenital cyst of the iris stroma. The embryological origin of these tumours is controversial owing to the clinical and histological aspects. Because the possibility of complications, excision is often necessary and permits accurate histologic diagnosis.

Epidermal Cyst↗
PubMed1987

Relapse of herpes simplex encephalitis.

This report describes a child with herpes simplex virus (HSV) encephalitis who improved dramatically while being treated with acyclovir but subsequently had neurological deterioration and died. A severe necrotizing process was present in the brain at autopsy but there were no focal areas of demyelination and poor inflammatory response. HSV was not cultured from brain biopsy during relapse or autopsy. Fourteen previous cases of relapsing herpes encephalitis are reviewed and treatment regime and mechanisms of relapse are discussed.

Acyclovir↗