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J Haot

Publications and source records attributed to J Haot.

At least 55 records · Page 3Linked to original sources
PubMed1984

Collagenous colitis: a transient condition? Report of two cases.

We have seen two patients with watery diarrhea whose work-up revealed a collagenous infiltration beneath the rectal epithelium. Within a year, symptoms disappeared in both. Repeated rectal biopsy revealed the disappearance of the collagen layer. Collagenous colitis may thus present as a transient condition.

Aged↗
PubMed1984

Cholestatic features in focal nodular hyperplasia of the liver.

Twenty specimens of focal nodular hyperplasia were studied with special attention to the histological features of chronic cholestasis (grouped under the headings of cholestasis, cholate-stasis and signs of ductular reabsorption). In all specimens, evidence was found for one or more features of cholestasis and cholate-stasis. Signs of ductular reabsorption were less constant, and apparently varied according to the developmental stage of the lesion. The cholestatic features emphasize the bile secretory capacity of the lesional parenchyma, and are apparently due to the lack of real bile ducts in the portal tract equivalents of the lesional tissue. Evidence is presented that the "ductular component" in FNH is not due to proliferation of pre-existing ductules, but rather derives from ductular metaplasia of liver cell plates in zone 1 equivalents. This metaplastic development of a ductular network may serve the function of reabsorbing the biliary constituents produced by the lesional parenchyma, leading to periductular inflammation and progressive fibrosis, thus producing an equivalent of biliary fibrosis and biliary cirrhosis.

Adult↗
PubMed1983

The pancreatic polypeptide cells in the human pancreas: the effects of age and diabetes.

Pancreases from insulin-dependent diabetics (IDDM), noninsulin-dependent diabetics (NIDDM), and nondiabetic subjects were analyzed by stereological and morphometrical methods in order to determine the weight of the lobe rich in pancreatic polypeptide (PP) cells in relation to the total weight of the pancreas and the volume density of PP cells in both parts of the gland, those rich and poor in PP cells. In control subjects, neither the relative weight of the lobe rich in PP cells, nor the volume density of PP cells varied significantly with aging. In IDDM and NIDDM, the volume density of PP cells was similar to that observed in control subjects. The total weight of the pancreas was markedly decreased in IDD because of an almost selective atrophy of the lobe poor in PP cells; the relative weight of the lobe rich in PP cells was thus much higher than that in control subjects. A less marked atrophy, restricted to the lobe poor in PP cells, was also observed in NIDDM. It is suggested that PP may exert a local trophic role which protects the lobe of the pancreas rich in PP cells from atrophy in diabetic patients. The results further show that the elevated levels of PP in the plasma of elderly or diabetic subjects cannot be ascribed to a hyperplasia of PP cells.

Adolescent↗
PubMed1979

Localization of pancreatic polypeptide cells in a limited lobe of the human neonate pancreas: remnant of the ventral primordium?

The localization of pancreatic polypeptide (PP) cells was studied in the pancreas of four human neonates by specific immunocytochemical techniques. PP cells were detected in all parts of the pancreas. However, examination at low magnification showed that they were considerably more numerous in a small lobe, located at the posterior-inferior part of the head region. It is suggested that this lobe corresponds to the part of the pancreas that is derived from the ventral primordium. Both in the lobe rich in PP cells and in the remainder of the pancreas, approximately 75% of PP cells were present in the islets and 25% distributed among acini and ducts.

Histocytochemistry↗
PubMed1976

[Influence of thymectomy on the lymphoid regeneration of hematopoietic bone marrow after sublethal irradiation].

In C57BL mice, bone marrow lymphoid regeneration after a sublethal irradiation is modified by a graft of normal marrow cells. This effect is suppressed in thymectomized mice since a lymphoid peak is observed after a 350 R irradiation; its composition is heterogeneous: small lymphocytes, lymphoblasts and peculier cells named "X cells". The same phenomenon is observed in mice where all the thymocytes and thymus derived and peripheral lymphocytes are destroyed. These results exclude that bone marrow lymphoid regeneration after irradiation is due to a migration of lymphoid cells of thymic origin to the marrow. They could be explained by the effect of a humoral thymic factor on marrow lymphopoiesis.

Animals↗
PubMed1975

Cellular repopulation and recovery of the phytogemagglutinine (PHA) responding cell pool in the thymus of sublethally irradiated mice.

Cellular repopulation and recovery of PHA reactivity was investigated in the thymus of mice exposed to 400 R either on the whole body or with one leg protected. In the whole body irradiated cases both the cellular repopulation and the restoration of PHA reactivity in the thymus showed a cyclic pattern: an initial depression and a subsequent first recovery being followed by a secondary cellular depletion and decrease of reactivity before another recovery phase started. The phase of the secondary decrease lasted fo a similar period for both the cell number and reactivity, but was shifted in time and the reduction in reactivity began some 12 days later than that in the cell number. In the leg-shielded animals, the cellular repopulation progressed without cyclic changes, but the recovery of PHA reactivity maintained a cyclic pattern. However, due to a smaller secondary decrease, it was less pronounced than in the whole body irradiated cases. During the aging of mice from 50 to 90 day old, the cell number in the involuting thymus decreased to half of the original. The decrease in the cell population was associated with an about four-fold increase of PHA reactivity. The results were discussed in regard to the origin of the immunoreactive thymic cells. Arguments were presented in favour of the hypothesis that both the reactive and nonreactive cells originate from precursors in common, but require different lengths of time for maturation.

Aging↗
PubMed1975

Cytological and ultrastructural study of the lymphoid-like and X cell populations in mouse bone marrow during the neonatal period.

During the recovery period following a sublethal irradiation, lymphoid-like cells accumulate in the bone marrow of the mouse. Among these cells, a peculiar element called 'X cell' has been previously described. Its morphological aspects are different from the precursors of the various hemopoietic lines. The 'X cell' could be an ancestral element normally repressed in the adult marrow. The aim of the present work is to determine whether this peculiar element can be detected in the bone marrow of young mice during the first month of life. The myelograms showed that on the day of birth, the marrow was almost exclusively composed of erythrocytic cells. During the postnatal period up to day 20, there was a progressive increase of granulocytic cells. The percentage of lymphoid-like cells increased from 5 per cent at birth to 28 per cent on day 20. The absolute number of these elements, calculated from the percentages obtained on the myelograms and from the number of nucleated cells per two femurs, increased from 20,000 at birth to 7,000,000 at day 30. The ultrastructural analysis demonstrated that the lymphoid-like population was composed of small lymphocytes, lymphoblasts and X cells, the proportions of which varied in relation to the age of the animals. X cells and lymphoblasts were found to be especially numerous around the 4th or 5th day, whereas the small lymphocytes were scarce.

Aging↗
PubMed1975

[Immuno-cyto-adhesion and sublethal irradiation].

1. In sublethally irradiated CBA mice, the relative and absolute numbers of spontaneous rosetts forming cells against sheep erythrocytes are markedly decreased in bone marrow. 2. The decrease of the absolute number of spontaneous RFC is also important in the spleen in spite of an increase of the RFC relative number above the normal values between the 8th and 12th day after irradiation. 3. The graft of normal bone marrow cells immediately after irradiation of the shielding of a medullary area during irradiation promotes the recovery of the immunocytoadherence capacity of the bone marrow cells but not of the spleen cells.

Animals↗