PubMed Health⌕ Search

Biomedical subjects

C Bergeron

Publications and source records attributed to C Bergeron.

At least 19 recordsLinked to original sources
PubMed1992

Diencephalic idiopathic gliosis: an unusual hypothalamic syndrome of dermopathy, diarrhea and growth arrest.

This case report of a 16-year-old girl describes the association of chronic diarrhea and lower limb dermopathy with an unusual and widespread gliosis within hypothalamic and other diencephalic structures. This syndrome to our knowledge has not been previously reported. Hypothalamic disease was suggested during life by examination findings of sustained hypothermia, altered sleep-wake cycles and abnormal cortisol diurnal rhythms. Profound growth arrest from the age of 8 yr (growth velocity < 1.4cm/yr) despite normal levels of growth hormone and response to physiological stimuli were additional unusual features. Autopsy after sudden death at 16 yr showed extensive gliosis in hypothalamic and adjacent diencephalic structures with proportionately little neuronal loss--suggesting an unidentified stimulus to glial proliferation. In the absence of evidence of other organ dysfunction it is suggested that dermopathy and chronic diarrhea in this case may have an autonomic basis. The impaired tissue response to growth hormone could be due to chronic hypothermia or involvement of some other (unidentified) hypothalamic factor regulating growth velocity.

Adolescent↗
PubMed1992

Reduction of vitamin D hormone receptor mRNA levels in Alzheimer as compared to Huntington hippocampus: correlation with calbindin-28k mRNA levels.

Receptors for vitamin D hormone (VDR) and the calcium binding protein, calbindin-28k, have been localized in many tissues, including brain. In brain, VDR and calbindin-28k were reported to colocalize in hippocampal CA1 cells. We have shown that mRNA pool size for calbindin-28k was reduced, on average, by 35% in Alzheimer hippocampal CA1 cells, as compared to Huntington control (manuscript in preparation). In the present study, in situ hybridization with tritiated antisense RNA probes was used to examine VDR expression in paired Alzheimer and Huntington brain tissue. Message levels for VDR were reduced, on average, by 34% and 31%, respectively, in Alzheimer hippocampal CA1 and CA2 pyramidal cells, as compared to Huntington control. However, VDR message levels were not significantly different from control in Alzheimer temporal cortex or cerebellum. There was no correlation between VDR message levels and brain weight, autopsy interval, patient age or the extent of neurofibrillary degeneration. Instead, VDR mRNA pool size in hippocampal CA1 cells correlated significantly with calbindin-28k message levels (r = 0.52, P less than 0.001). Decreased message levels for VDR and calbindin-28k in these cells were due to an increased percentage of cells expressing lower message levels for these proteins. These results show that in Alzheimer hippocampal CA1 cells, VDR mRNA pool size is downregulated and that this downregulation may play a role in the reduction of calbindin-28k expression.

Alzheimer Disease↗
PubMed1992

Effects of experimental conditions on the production of interleukin-1 alpha and -1 beta by human endothelial cells cultured in vitro.

We have characterized the production of IL-1 alpha and -beta in primary and passaged cultures of quiescent human umbilical vein endothelial cells (HUVECs) using highly specific and sensitive solid-phase enzyme immunoassays. Primary cultures produced both immunoreactive IL-1 alpha and IL-1 beta following stimulation with lipopolysaccharide with the alpha form predominating over the beta. Most of the IL-1 produced remained cell-associated. Primary, but not passaged, cultures were significantly contaminated by macrophage-like cells, possibly accounting for higher production of IL-1, especially IL-1 beta. Gel filtration of secreted proteins derived from cultured HUVECs showed that the immunoreactive IL-1 alpha exhibited the expected molecular weight (17 kDa), but cell-associated IL-1s appeared to be a mixture of the 17 kDa protein and of higher molecular weight precursors. Mitogens in the culture medium (serum and endothelial cell growth supplement) were powerful stimuli of endothelial IL-1 production and accounted for the relatively high basal IL-1 levels observed in the cultured endothelial cells. The proliferative phenotype of the endothelium is possibly linked to the expression of high level of IL-1, which until now was thought to be an autocrine inhibitor of endothelial cell mitosis.

Cells, Cultured↗
PubMed1992

Human papillomaviruses associated with cervical intraepithelial neoplasia. Great diversity and distinct distribution in low- and high-grade lesions.

All together, 30 genital human papillomavirus (HPV) types have been characterized so far. To evaluate the importance of HPV diversity in associated cervical diseases, we analyzed 188 biopsy specimens obtained from patients with a recent diagnosis of cervical HPV infection or intraepithelial neoplasia (CIN). Of these 188 specimens, 116 were classified as low-grade CIN (48 cases), high-grade CIN (53 cases), condylomata acuminata (10 cases), flat condylomas (five cases). Seventy-two specimens were considered nondiagnostic. Using probes specific for 18 genital HPV types, HPV DNA sequences were detected by Southern blot hybridization in 100 lesions and 21 nondiagnostic specimens. When further analyzed by the polymerase chain reaction, eight HPV-negative biopsy specimens, four CIN, and four nondiagnostic specimens were positive. Of the 129 positive biopsy specimens, 92 contained at least one of 18 known HPV types and 37 HPV that have not yet been identified. Nine specimens had more than one type. Thirteen HPV types were identified in CIN. The detection rate of HPV 16 increased from 21% in low-grade CIN to 57% in high-grade CIN. HPV 18 was detected in only 3% of CIN; HPV 31, 33, and 35 were found in 8%. HPV 30, 39, 45, 51, 52, 56, 58, and 61 were detected in 44% of low-grade CIN but in only 8% of high-grade CIN. Unidentified HPV were detected in about 25% of low-grade and high-grade CIN. Fifty-seven CIN positive for at least one HPV type were further analyzed by in situ hybridization. Thirty-five (65%) biopsy specimens were positive, including 21 of 24 low-grade CIN and 14 of 33 high-grade CIN. Ten of the 13 previously identified HPV types were detected. Thus, CIN represents an heterogeneous disease from a virologic viewpoint. This fact could explain their variable clinical evolution.

Adolescent↗
PubMed1992

Brain cytochrome oxidase in Alzheimer's disease.

A recent demonstration of markedly reduced (-50%) activity of cytochrome oxidase (CO; complex 4), the terminal enzyme of the mitochondrial enzyme transport chain, in platelets of patients with Alzheimer's disease (AD) suggested the possibility of a systemic and etiologically fundamental CO defect in AD. To determine whether a CO deficiency occurs in AD brain, we measured the activity of CO in homogenates of autopsied brain regions of 19 patients with AD and 30 controls matched with respect to age, postmortem time, sex, and, as indices of agonal status, brain pH and lactic acid concentration. Mean CO activity in AD brain was reduced in frontal (-26%: p less than 0.01), temporal (-17%; p less than 0.05), and parietal (-16%; not significant, p = 0.055) cortices. In occipital cortex and putamen, mean CO levels were normal, whereas in hippocampus, CO activity, on average, was nonsignificantly elevated (20%). The reduction of CO activity, which is tightly coupled to neuronal metabolic activity, could be explained by hypofunction of neurons, neuronal or mitochondrial loss, or possibly by a more primary, but region-specific, defect in the enzyme itself. The absence of a CO activity reduction in all of the examined brain areas does not support the notion of a generalized brain CO abnormality. Although the functional significance of a 16-26% cerebral cortical CO deficit in human brain is not known, a deficiency of this key energy-metabolizing enzyme could reduce energy stores and thereby contribute to the brain dysfunction and neurodegenerative processes in AD.

Aged↗
PubMed1992

Detergent-insoluble cortical Lewy body fibrils share epitopes with neurofilament and tau.

Lewy bodies are cytoskeletal inclusions associated with neuronal injury and death in idiopathic Parkinson's disease and other neurodegenerative disorders. The chemical composition of the 8-10-nm fibrils of the Lewy body is unknown, although they are related to both normal cytoskeletal elements and paired helical filaments of Alzheimer neurofibrillary tangles. From the Lewy body-rich cerebral cortex of patients with diffuse Lewy body disease we have isolated intact Lewy bodies using a high salt buffer/nonionic detergent gradient centrifugation procedure and extracted the constitutive fibrils with urea and sodium dodecyl sulfate. Urea/detergent-resistant Lewy body fibrils were solubilized with formic acid and found to contain a single protein band of 68 kDa, which was not found in identically prepared normal brain homogenates. The Lewy body derived-polypeptide was recognized on immunoblots by a polyclonal antibody that reacted with both the 68-kDa neurofilament subunit and the microtubule-associated protein tau. The 68-kDa Lewy body protein was not labeled by the monoclonal antibody tau-1 despite prior in vitro enzymatic dephosphorylation. We conclude that the detergent-insoluble component of the cortical Lewy body fibril shares epitopes with neurofilament and tau and may be a posttranslationally modified derivative of either neurofilament or tau with substantially altered biochemical and immunologic properties.

Amino Acids↗
PubMed1992

Alloimmune thrombocytopenia: in utero treatment by high doses of intravenous gamma globulins.

The authors report successful in utero treatment by high doses of intravenous gamma globulins in a case of neonatal alloimmune thrombocytopenia. Early diagnosis allows an appropriate management: fetal blood sampling as early as 20 weeks of gestation; in case of fetal thrombocytopenia, treatment by intravenous gamma globulin (1.0 g/kg/b.w.) each week during 8 weeks or more; ultrasound screening of in utero hemorrhage, particularly intracranial hemorrhage; fetal blood sampling before delivery at term and in utero transfusion of platelet antigen negative in case of persistence of fetal thrombocytopenia.

Adult↗
PubMed1992

Effects of luteal estradiol on the secretory transformation of human endometrium and plasma gonadotropins.

To study the role of luteal estradiol (E2), we interrupted the supply of E2 during the luteal phase of E2 and progesterone (P) replacement cycles. Thirty-one women, aged 26-37 yr, with absent or inactive ovaries received three different treatment regimens: group I (n = 11) received transdermal E2 and vaginal P according to a protocol designed to approximate levels of estrone (E1), E2, and P seen during the menstrual cycle. Groups II (n = 11) and III (n = 9) received identical treatments, except that in group II no E2, and in group III no E2 or P, was administered after day 15. Endometrial biopsies were obtained on days 20 and 24 in groups I and II, and on days 14 and 20 in group III. In group I, plasma E1 and E2 reached menstrual cycle levels, whereas in groups II and III, discontinuation of the E2 supply on day 15 resulted in a prompt decrease to castrate levels of plasma E1 and E2. In groups I and II, menopausal FSH and LH levels decreased to 26 +/- 6 and 30 +/- 7 IU/L, respectively, on day 13 (mean +/- SEM). In group I, administration of E2 and P starting on day 15 further lowered plasma gonadotropin levels. In group II, administration of P only failed to induce a similar decrease in plasma FSH and LH. No uterine bleeding occurred before day 25 in women of groups I or II, while women of group III bled within 2 days of E2 withdrawal. Endometrial biopsies were similar in groups I and II. Histological features were characteristic of early and late luteal phases on days 20 and 24, respectively. Endometrial maturation assessed by estrogen and progesterone receptors identified by immunocytochemistry showed the typical distribution seen on day 24 of the menstrual cycle with no difference between groups I and II. We conclude that in women deprived of ovarian function, administration of P only after 14 days of E2 priming prevented uterine bleeding and induced normal secretory transformations of the endometrium, but failed to suppress plasma gonadotropins.

Administration, Cutaneous↗
PubMed1992

Molecular and prospective phenotypic characterization of a pedigree with familial Alzheimer's disease and a missense mutation in codon 717 of the beta-amyloid precursor protein gene.

We present prospective clinical and neuropathologic details of a pedigree segregating familial Alzheimer's disease (FAD) associated with a mutation (G----A substitution) at nucleotide 2149 in exon 17 of the amyloid precursor protein (APP) gene. This mutation, which is predicted to cause the missense substitution of isoleucine for valine at codon 717 of APP, cosegregated perfectly with the FAD trait (lod score = 3.49 at theta = 0.00). The earliest clinical manifestations of the disease relate to deficits in memory function, cognitive processing speed, and attention to complex cognitive sets. These changes occurred in the absence of changes in nonmemory language and visuospatial functions. The neuropathologic features of FAD associated with the APP717 mutation in this family include severe neuronal loss, abundant neurofibrillary tangles, amyloid plaques, and amyloid angiopathy. These results provide independent confirmation that mutations in the APP gene are linked to the FAD trait in some families.

Adult↗
PubMed1991

Hereditary diabetes insipidus: an immunohistochemical study of the hypothalamus and pituitary gland.

We report the histological findings in a case of hereditary diabetes insipidus (HDI) using vasopressin (VP) immunohistochemistry. The hypothalamus displayed a marked loss of magnocellular VP neurons, with preservation of the smaller cells. The neurohypophysis was severely atrophic with scanty immunoreactivity. Our results support the hypothesis that HDI results from a selective degeneration of VP neurons affecting chiefly the magnocellular elements projecting to the neurohypophysis. The sparing of the parvocellular component may reflect the projection of these neurons to non-pituitary targets.

Aged↗
PubMed1991

Localization and quantitation of 68 kDa neurofilament and superoxide dismutase-1 mRNA in Alzheimer brains.

The technique of in situ hybridization with tritiated RNA probes was used to study the expression of the 68 kDa neurofilament (NF68) gene and the superoxide dismutase-1 (SOD-1) gene in the brains of Alzheimer's disease (AD) patients. Messenger RNA (mRNA) for these proteins was localized and quantified in single cells of formalin-fixed, paraffin-embedded sections of 4 pairs of AD and Huntington's disease (HD) brains from patients matched for age at death and autopsy interval. The cerebellar cortex and hippocampal CA1 and CA2 regions were compared in these two groups of subjects, since in AD the CA2 region of the hippocampus and the cerebellum have been found to be relatively unaffected by the Alzheimer process in comparison to the hippocampal CA1 region. The amount of NF68 mRNA was reduced by approximately 50% in pyramidal cells of both the CA1 and CA2 of AD hippocampus (P less than 0.001), and by 15% in the Purkinje cells of AD cerebellum (P less than 0.05) relative to that of the HD individuals. SOD-1 mRNA was reduced by about 22% in the CA1 of AD brains (P less than 0.001) with no corresponding reduction in the CA2, and by only 5% in the AD cerebellum (P greater than 0.5). The paired design of the study suggests that these results are not simply attributable to the effects of autopsy interval or the agonal process in each patient's death.

Alzheimer Disease↗
PubMed1991

Controlled preparation of the endometrium with exogenous estradiol and progesterone in women having functioning ovaries.

OBJECTIVE: To determine if controlled preparation of the endometrium with exogenous estradiol (E2) and progesterone (P) could be achieved in women retaining their ovarian function without requiring prior ovarian suppression with a long-acting agonist of gonadotropin-releasing hormone (GnRH-a). DESIGN: Prospective feasibility study of a new simplified hormone regimen for preparation of endometrium receptivity. Six volunteer women received transdermal E2 and vaginal P without prior suppression of their ovarian function with GnRH-a. The control group consisted of previously reported cases receiving GnRH-a and E2 and P. SETTING: Academic tertiary care institution. PATIENTS: Six volunteer women. MAIN OUTCOME MEASURES: Participants received transdermal E2 and P after a regimen designed to duplicate the plasma E2 and P levels seen in the menstrual cycle. INTERVENTION: Endometrial biopsy. RESULTS: Plasma luteinizing hormone increased to surge levels in one woman on day 11, in two on day 12, and on day 14 in the remaining three women. No follicular growth was noticed on ultrasound, and no increase in plasma P occurred before the onset of P administration on day 15. Day 20 endometrium specimens showed early secretory changes as previously reported in women deprived of ovarian function receiving similar hormonal treatment. CONCLUSIONS: Our results indicate that controlled preparation of the endometrium can be achieved with exogenous E2 and P without prior ovarian suppression with a GnRH-a in women having functioning ovaries. Hence, administration of exogenous E2 and P appears to be a viable simpler alternative to the combined administration of GnRH-a and exogenous E2 and P, which avoids the side effects and the cost of GnRH-a.

Adult↗
PubMed1991

Immunocytochemical localization of oestradiol and progesterone receptors in human endometrium: a tool to assess endometrial maturation.

Uterine oestrogen (ER) and progesterone (PR) receptors are subject to fine hormonal control by oestradiol and progesterone. In order to assess the role of ER and PR measurement in the evaluation of endometrial maturation, both receptors were studied by immunocytochemical techniques using monoclonal antibodies during the menstrual cycle, and in women with inactive ovaries treated by different regimens of hormonal substitution with oestradiol and progesterone. During the normal menstrual cycle, the concentrations and distribution of ER and PR changed markedly. During the mid follicular period (days 7-8), a small proportion of stromal and glandular cells stained positively for PR while staining for ER was more intense and more frequent. During the late follicular phase and early luteal period (days 9-19), the staining for PR increased markedly in glandular cells. During the mid and late luteal phase (days 21-27), ER and PR staining disappeared in glandular cells. Thus, while oestradiol increases the staining for ER and PR in both glands and stroma, progesterone decreases ER and PR staining in the glands in a dramatic fashion. These variations, especially the disappearance of PR under the effect of progesterone, are potentially useful for studying the cumulative effect of progesterone on endometrial maturation. This was confirmed in anovulatory women, where a late luteal phase aspect was observed, i.e. the absence of a reduction in ER and PR in glandular cells. In women with ovarian failure, the disappearance of ER and PR in glandular cells is correlated with the duration of progesterone therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Histology of the human endometrium: from birth to senescence.

Embryologically, the human endometrium is of mesodermal origin, and constitutes the mucosal lining of the fused Mullerian ducts of the uterus. In the adult, premenopausal woman, the endometrium follows a precisely programmed series of morphologic and physiologic events, characterized by growth, secretory differentiation, and in the absence of conception, degeneration and regeneration. Proliferation, secretion and degeneration are confined to the upper functionalis layer, whereas the lower basalis layer is the seat of regenerative endometrium. In the postmenopausal years, absence of biologically significant estrogenic stimulation leads to progressive endometrial involution, from proliferative to inactive in the mid-50s to atrophy in the late-60s. Cyclic endometrial alterations are controlled by the ovarian estrogens and progesterone via their respective endometrial intranuclear receptors, and possibly other peptides and enzymes. They provide appropriate environment for the implanting conceptus. The intimate inter-relationship between endometrial structure/function and steroid hormones during the premenopausal period serves as an indicator of the hypothalamo-pituitary-ovarian axis as related to ovulatory states.

Aging↗
PubMed1991

A family with multiple instances of definite, probable and possible early-onset Alzheimer's disease.

A family with a multigenerational history of proven or suspected early-onset Alzheimer's disease (AD) consistent with autosomal-dominant inheritance is described. To date, the pedigree comprises five generations in which there are 13 known affected individuals. The mean age of onset of cognitive deficits in those for whom data are available (n = 11) is 47.6 (s.d. 3.0) years and the mean age of death (n = 10) is 58.8 (s.d. 4.0) years. The variability in the extent and quality of available data illustrates the diagnostic difficulties encountered in ascertaining such an extended pedigree, and the need for caution in interpreting the evidence.

Adult↗