Cognitive impairment in obstructive sleep apnea.

Obstructive sleep apnea (OSA) is characterised by repetitive cessation or reduction of airflow due to upper airway obstructions. These respiratory events lead to chronic sleep fragmentation and intermittent hypoxemia. Several studies have shown that OSA is associated with daytime sleepiness and cognitive dysfunctions, characterized by impairments of attention, episodic memory, working memory, and executive functions. This paper reviews the cognitive profile of adults with OSA and discusses the relative role of altered sleep and hypoxemia in the aetiology of these cognitive deficits. Markers of cognitive dysfunctions such as those measured with waking electroencephalography and neuroimaging are also presented. The effects of continuous positive airway pressure (CPAP) on cognitive functioning and the possibility of permanent brain damage associated with OSA are also discussed. Finally, this paper reviews the evidence suggesting that OSA is a risk factor for developing mild cognitive impairment and dementia in the aging population and stresses the importance of its early diagnosis and treatment.

The value of woody hedgerows for moth diversity on organic and conventional farms.

Habitat destruction and degradation are important drivers of biodiversity loss within agro-ecosystems. However, little is known about the effect of farming practices and the value of woody hedgerows on Lepidoptera in North America. The purpose of this work was to study moth diversity in woody hedgerows and croplands of organic and conventional farms. In addition, the influence of vegetation composition and abiotic variables on species richness, abundance, and composition was examined. Moths were sampled with light traps during six weeks in the summer of 2001. Vegetation data and abiotic variables were obtained for all sites. In total, 26,020 individuals from 12 families and 408 species were captured. Most species were uncommon. Only 35 species included >100 individuals while for 71% of species <10 individuals were found. The Noctuidae represented 221 species and 85% of all individuals captured. Woody hedgerows harbored more species and in greater number than croplands. There was no significant difference in moth diversity between organic and conventional farms, except that the Notodontidae were significantly more species rich in organic than in conventional sites. Results show that species richness, abundance, and composition were greatly influenced by habitat types (hedgerow versus crop field) and abiotic variables (minimum temperature which was correlated to moon illumination, rainfall, and cloud cover). Moth species composition was significantly correlated to vegetation composition. This study broadens our understanding of the factors driving moth diversity and expands our knowledge of their geographic range. The maintenance of noncrop habitats such as woody hedgerows within agro-ecosystems seems paramount to preserving the biodiversity and abundance of many organisms, including moths.

On the use of scaling factors to improve interspecies extrapolation of acute toxicity in birds.

In avian toxicology, it is customary to extrapolate between species on the basis of acute toxicity measurements expressed in mg/kg body weight. Recently, it has been suggested that extrapolations should be on the basis of weight raised to the 0.6-0.7 power because there is good empirical evidence that, for mammals, this produces the best agreement between species. We used an avian LD50 database to derive empirically the appropriate scaling factor for birds. With a subset of 37 pesticides of varying structures but heavily weighted to cholinesterase inhibitors, we found that the appropriate scaling factor in birds is usually higher than 1 and can be as high as 1.55. Extrapolations on the basis of weight alone or, worse, the use of inappropriate mammalian scaling factors could lead to serious underprotection of small-bodied bird species modeled in the course of risk assessment procedures.

Unusual amyloid polyneuropathy with predominant lumbosacral nerve roots and plexus involvement.

We report a 25-year-old patient with a progressive asymmetric peripheral neuropathy of the distal lower limbs. Imaging studies showed enlargement of lumbosacral roots, plexus, and proximal sciatic nerve. Sacral plexus biopsy revealed amyloidosis associated with endoneurial edema. Immunohistochemistry with anti-prealbumin, serum amyloid A, and immunoglobulin light chain antisera failed to label the amyloid.

[Two benign vascular tumors of the kidney capsule]. / Deux tumeurs vasculaires bénignes de la capsule du rein.

Capsular tumors of the kidney are uncommon or poorly documented. The authors report two cases of benign vascular tumors: a so-called "vascular leiomyoblastoma" and a glomus tumor. An ultrastructural study of the first tumor demonstrated smooth muscular characteristics. Obvious histological features of glomus were seen in the second. Immunohistochemical study revealed positive immunoreactivity for epithelial and mesenchymal antibodies in the two tumors. Glomus tumor originates from the particular system of vessels in the capsule. Histogenesis of the vascular leiomyoblastoma is more controversial. This tumor could be akin to leiomyomas of the renal capsule and intra parenchymatous leiomyomas; lymphatic origin and even a glomangiomatous nature are also possible explanations.

A quantitative study of epithelial alterations during the early stages of experimental colonic tumorigenesis in mice.

The weekly administration of 1,2-dimethyl-hydrazine (DMH) by subcutaneous injection for a period of 16-20 weeks is a well known procedure for producing colonic tumors in mice and rats. Quantitative histomorphological, histochemical and kinetic studies, as well as investigation of the significance of epithelial cell density were carried out in mice between the 7th and the 91st day after the first DMH injection. These studies showed that between the 28th and the 35th day, several simultaneous alterations in the colonic epithelium involving modification of glandular form, decreased mucus secretion, an increase in epithelial cell density and an increase in the number of S phase cells (BrdU labeling index: LI). Around the 35th day, the glands tended to expand and from the 35th to the 63rd day, they were stretched and displayed compartments of dedifferentiated and non-mucinous crypts (DNMC). In these crypts the cell density became very high, reaching twice the control value on the 91st day. This feature was accompanied by alteration in cell morphology and by an increase in the available basement membrane area. A decrease in mucus secretion was apparent from the 14th day and by the 63rd day, mucus secretion was only about 60% of the control value in all crypts. The LI was increased until the 35th day following which a paradoxical and progressive decrease occurred in all glandular compartments.

[Thymoma and lupus: apropos of a case with recurrences and histological dedifferentiation]. / Thymome et lupus: à propos d'un cas avec rechutes et dédifférenciation histologique.

A case of thymoma associated with chronic lupus erythematosus is reported. The course of the lupus was parallel to that of the thymoma, with several successive relapses. Histologically, the thymoma became increasingly undifferentiated. Chemotherapy only resulted in a few months of remission.

[Intrapulmonary chemodectoma. A new case with ultrastructural study]. / Chémodectome intra-pulmonaire. Un nouveau cas avec étude ultrastructurale.

The authors report the case of a 40-year old woman who presented with a round tumour in the middle lobe of the right lung. Once removed, the tumour proved to be an intrapulmonary chemodectoma. Chemodectomas are tumours that are rarely present in the lung. Their pathogenesis is open to discussion. Their study by electron microscopy is interesting, as it shows grains of neurosecretion and provides additional information on the morphology of chemoreceptors.

[The employee support program at Pratt and Whitney.]. / Programme d'aide à l'employé chez Pratt et Whitney.

In this article, the authors survey the evolution of the Pratt & Whitney company's assistance program for their employees. Observing that their employees had problems with alcoholism, the personnel development developed a help program for the alcoholics which in the course of the years has also become a help program to the alcoholic's families. The authors summarize the principal problems treated, the program's mode of operation and make a summary evaluation.

[Epidermotropic eccrine carcinoma. Apropos of a case with ultrastructural examination]. / Le carcinome eccrine épidermotrope. A propos d'une observation avec étude ultra-structurale.

Pinkus and Mehregan's epidermotropic eccrine carcinoma shows particular clinico-pathological characteristics which makes it different from the other cutaneous epitheliomas. A case observed on a 81 year old woman is reported. The initial lesion consisted of an ulcerating tumor on the calf, then followed by multiple verrucous papules eruption around it. Within a few weeks, many other verrucous tumors occurred on the upper part of the leg while a lymphedema was developing. One year after the initial lesion has been noticed, the patient died of metastases in distant organs. From a histological point of view, the tumor corresponded to a squamous cell carcinoma that was slightly keratinizing, Bowenoïd epidermotropic, with dermal involvement too. Features of duct formation were identified within solid nests of neoplastic cells, tumor emboli were seen in the lymphatics. The ultra-structural study made it evident that the tonofilaments were precarious in neoplastic cells; the cytoplasm contained glycogen. The inter-cellular bridges and desmosomes were scanty and micro-villi were noted. The latter confirm the sudoral nature of these cells. For Pinkus and Mehregan, this type of tumor originates in the acrosyringium, but we think that a contiguous segment of the sudoral duct must also be probably concerned. The spreading of the epidermotropic eccrine carcinoma occurs in the teguments themselves in a uncommon way. The tumor re-appears from the dermal lymphatic channels. The lymphatic involvement is the main characteristic of this cutaneous carcinoma, verified by metastases existing in distant organs.

[Carney's triad]. / La triade de Carney.

The triad described by J.A. Carney in 1977 is characterized by the successive or concomitant occurrence of three rare tumours of different origin: gastric leiomyoblastoma, functioning extra-adrenal paraganglioma and pulmonary chondroma. It is found mainly in young female patients with prevalent blood group A and may be incomplete, with only two of the three tumours occurring. The case of a young woman who developed gastric leiomyoblastoma and, six years later, pelvic paraganglioma is reported; she died of metastases from the paraganglioma with malignant hypertension. The 16 cases already published are reviewed. The authors insist upon the severity of paragangliomas and the need for a systematic search for the other tumours in patients who present with one tumour of the triad. A histogenetic interpretation relating the tumours to pathology of the neural crest is suggested.

Measurement of changes in amino acids related to total collagen in fibrotic human liver.

In the liver, total collagen accumulation during the fibrotic or cirrhotic process was measured using a methodology based on the determination of collagen amino acids in liver biopsies from adults with alcoholic liver diseases or children with biliary atresia. The results obtained with this methodology were compared to histopathological findings. Thus, it was shown that generally the severity of hepatic injury was dependent on collagen accumulation. In biliary atresia, collagen accumulation increased with the children's age despite reconstructive surgery and restoration of biliary flow.

Consequences of diabetes mellitus or liver cirrhosis on total collagen in human skin biopsies.

In this work, we studied the changes in human skin collagen occurring in diabetes mellitus and liver cirrhosis. The original methodology, based on the determination of the amino acids proline, 4-hydroxyproline, hydroxylysine, glycine and alanine, allowed us to reveal in skin a change in collagen in diabetes mellitus but none in liver cirrhosis. This biochemical evidence was correlated to the histological investigation. Moreover, diabetes mellitus did not involve any changes in hydroxylation of polypeptidic lysine. This latter observation was in accordance with the accumulation of normal collagen regarding amino acid composition only, and the results suggest a preferential accumulation of collagen type III in skin, in diabetes mellitus.

An autoradiographical topological study of the epithelial cell proliferative activity in the ascending colon of the mouse using a modified technique for determining the fraction of labelled mitoses (FLM).

In a previous study of the mouse ascending colon we showed that epithelial cell proliferation is more active on the tops of mucosal folds than in the flat mucosal areas between folds. In order to define the cytokinetic characteristics of this phenomenon more precisely, we have undertaken an autoradiographic investigation with 3H-thymidine. The fraction of labelled mitoses (FLM) curves and cell labelling indices have been worked out in fold top areas (FTA) and on flat areas off the folds (OFA). A new method has been adopted to draw the FLM curves. The results show no difference between the cell cycle times or in the times corresponding to G2-phase and S-phase in FTA and OFA. In contrast, the proliferative cell compartment in FTA is 40% higher than in OFA.

[Colonic localization of pseudopolypoid type disclosing Recklinghausen's neurofibromatosis]. / Une localisation colique a forme pseudo-polypeuse révélatrice d'une neurofibromatose de Recklinghausen.

A case of colonic Recklinghausen neurofibromatosis found in a forty-two-year-old woman is presented. Only the colon was affected. The first symptom was rectal bleeding. Widespread polypoid lesions involving the rectum, sigmoid, left colon and part of the transverse colon were demonstrated upon barium enema and rectosigmoidoscopic examinations. As demonstrated by a review of the medical literature, colonic involvement in Recklinghausen disease is very infrequent and forms restricted to the colon are exceptional. The pathologic findings and the clinical, radiological and endoscopic features in colonic neurofibromatosis are described. It seems that total colectomy should be advocated. Our patient underwent total colectomy ten years ago and has experienced neither recurrence nor other manifestations of Recklinghausen disease.

A topological study of the epithelial cell proliferation in the ascending colon of the mouse.

Epithelial cell proliferation has been studied from a topological point of view, in the ascending colon of the mouse. The ascending colon was investigated because it offered the possibility of studying distinct mucosal sites according to whether they are situated on folds or away from the folds. Consequently fold top areas (FTA), fold side areas (FSA), flat mucosa areas (OFA) have been studied individually. To determine mitotic activity, we have used the technique of arrested metaphases by a stathmokinetic agent. The estimate of the epithelial compartment size has been undertaken according to a stereological methodology. The topographical study consisted of three parts: a reproduction of the mitotic density distribution on a colonic area of significant importance; a topographical stathmokinetic study; a reconstitution of the profile of mitotic densities all along a mean model mucosal fold. The findings obtained from these different approaches present evidence that the distribution of mitotic activity within the colon is not homogeneous, that the relief of the mucosa is a factor occurring in proliferative cellular activity. The highest mitotic densities are situated on FTA, and the lowest ones on OFA. Mitotic density increases on the fold, in the terminal fifth of its length.