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Biomedical subjects

M J Phillips

Publications and source records attributed to M J Phillips.

At least 181 records · Page 10Linked to original sources
PubMed1983

Intrahepatic cholestasis as a canalicular motility disorder. Evidence using cytochalasin.

A rich network of actin-containing microfilaments are associated with the plasma membrane of the liver cells. These filaments are especially numerous in the pericanalicular region. Recently, active contractions of bile canaliculi have been observed in normal coupled isolated hepatocytes. In this report, we document that this motility behavior is abolished by cytochalasins B and D. Other cytoplasmic contractile movements are also reduced or lost after a brief initial period of enhanced surface activity with the formation of zeiotic blebs. The lack of contractile activity of bile canaliculi is accompanied by the gradual dilation of canalicular lumina. Since there is overwhelming evidence that the functional effects of the cytochalasins on cell motility are due to their effects on actin filaments, we propose that the altered canalicular contractility observed is due to the effects of cytochalasin on pericanalicular actin filaments. If bile canalicular contractility is a requirement for normal bile flow, then interference with this mechanism may be a factor in the pathogenesis of some types of intrahepatic cholestasis.

Animals↗
PubMed1982

An examination of blood steroid and gonadotropin concentrations in relation to fertility status and testicular function in men.

Plasma concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), testosterone (T), and 17 beta-estradiol (E2) have been measured in men complaining of infertility in comparison with men of proven fertility. Subgrouping of patients was achieved on the basis of the presence or absence of sperm in the ejaculate and further by the concentration of sperm or by testicular score. The levels of plasma LH, FSH, PRL, and T were found to be significantly different in the fertile men, compared with both infertile men with sperm in their ejaculates and azoospermic men. There were no significant differences between the groups for E2. There appeared to be an inverse relationship between LH concentrations and sperm count in both fertile and infertile men. FSH levels did not vary significantly in the fertile men in relation to sperm count grouping but were significantly less than those found for the infertile men with sperm. Azoospermic patients with high testicular scores had FSH levels indistinguishable from those of the fertile men. The results are discussed in terms of testicular abnormalities and on the interrelationship between the hormones examined.

Estradiol↗
PubMed1982

Histamine, neutrophil chemotactic factor and circulating basophil levels following exercise in asthmatic and control subjects.

Significant increase in the maximum post-exercise values of plasma histamine (PH), whole blood histamine (WBH) and neutrophil chemotactic factor (NCF) occurred in arterial blood within the first hour after exercise in asthmatic patients. However, similar changes in PH and WBH also occurred in the control group. Significant increases in circulating basophil counts following exercise were found in both groups, which closely mirrored the changes in PH and NCF, and there was a highly significant correlation between rises in WBH and basophil counts (P less than 0.001). When plasma histamine as assayed in venous blood using a more sensitive and specific double isotope radio enzymatic assay no significant alteration in plasma histamine levels was detected in either the asthmatic or the control group. We conclude that there is no evidence from these studies to support the suggestion that mast cell mediator release is involved in the pathogenesis of exercise-induced asthma, and that any observed changes in levels of PH and NCF after exercise may be related to changes in levels of circulating basophils.

Adult↗
PubMed1981

Contractility of bile canaliculi: implications for liver function.

Dynamic contractions of bile canaliculi were observed in groups of cultured hepatocytes by time-lapse cinephotomicrography during the early stages of monolayer formation. The contractions, which were forceful and appeared to have a pumping action, may facilitate the flow of bile in the liver's canalicular system.

Animals↗
PubMed1981

Spleen scanning with 99Tcm-labelled red blood cells after splenectomy.

In order to correlate the haematological changes which occur after splenectomy, with the presence or absence of residual splenic tissue, spleen scans using 99Tcm-labelled red blood cells were performed in 36 patients who had had a splenectomy. Positive spleen scans were found in 44 per cent (8 out of 18) of patients who had undergone splenectomy for trauma and in 17 per cent (3 out of 18) of patients who had undergone elective splenectomy. No relationship was found between the presence of Howell-Jolly bodies, platelet counts, the levels of IgG, IgM and IgA and the scan result. It is concluded that these findings are due to the presence of splenunculi, whose incidence is more common than the 12 per cent usually quoted.

Adolescent↗
PubMed1981

Modern aspects of the morphology of viral hepatitis.

The morphologic pathology of human viral hepatitis and its sequelae are reviewed in this article. Emphasis is placed on new information, including the current status of the pathologic diagnosis of hepatitis non-A, non-B. The article includes a discussion of aspects of the virology that are pertinent to an understanding of the significance of viral markers in the liver. A small contribution of the authors is a brief description of the neocholangiole, a duct of Hering-like structure seen following hepatic necrosis from many causes, including the severe forms of viral hepatitis.

Acute Disease↗
PubMed1981

Effects of cytochalasin B on membrane-associated microfilaments in a cell-free system.

The mode of action of cytochalasin B was examined in vitro using bile canaliculus-enriched plasma membrane fractions isolated from rat liver. The pericanalicular microfilaments, which are mainly actin filaments and which are normally attached to the canalicular membranes, were dissociated from the membranes by cytochalasin B treatment. A microfilamentous network was found in the supernate of the cytochalasin B treatment. A microfilamentous network was found in the supernate of the cytochalasin-treated specimens and a number of polypeptides, of which a polypeptide corresponding in molecular weight to actin was a notable member. These results suggest that actin filaments become detached from the canaliculus membranes by cytochalasin B.

Actins↗
PubMed1981

Respiratory tract reactions to western red cedar.

1 Asthma due to western red cedar (Thuja plicata) is well recognized, but has not been described frequently in the UK. Two patients who developed asthma and rhinitis due to occupational contact with western red cedar were studied. Both patients developed late asthmatic responses following bronchial challenge with western red cedar. 2 The challenge technique and the results of comparison between different wood dusts and dust extract are described. 3 The technique of anterior rhinometry was used to follow the nasal response to challenge in one patient, and demonstrated a late nasal reaction which followed a similar time course to the bronchial response.

Adult↗