Some marine ecological phenomena: chemical basis and biomedical potential.

Analysis of secondary metabolites derived from marine organisms has revealed a broad spectrum of novel molecular architecture. The function of these compounds in their natural habitat is linked to various aspects of species survival, and the compounds have also served as characteristic chemical markers through successive trophic levels. Fundamental questions concerning the locus of synthesis in complex and intricate assemblies of plants and animals and the pathways of biosynthesis are beginning to be answered. It is now apparent that the marine environment gives rise to some distinctive chemistry, which is generated along characteristic pathways. Some of the newly described compounds have already become valuable tools in biomedicine.

Photosynthetic Marine Mollusks: In vivo 14C Incorporation into Metabolites of the Sacoglossan Placobranchus ocellatus.

In seawater enriched with carbon-14-labeled sodium hydrogen carbonate the sacoglossan Placobranchus ocellatus when exposed to light incorporates carbon-14 at a rate 50-fold of that for animals kept in the dark. 9,10-Deoxytridachione, a secondary metabolite of the mollusk, undergoes a photorearrangement to photodeoxytridachione in vivo.

Palytoxin: a new marine toxin from a coelenterate.

Palytoxin has been isolated from the zoanthids "limu-make-o-Hana" (Tentatively identified as Palythoa sp.) as a noncrystalline, chromatographically pure entity. Apart from polypeptide and protein toxins, it is the most highly toxic substance known, with a lethal dose (LD(59)) in mice of 0.15 microgram per kilogram by intravenous injection. Unlike the potent toxins batrachotoxin, saxitoxin, and tetrodotoxin which have molecular weights of 500 or less, palytoxin has an estimated molecular weight of 3300 and contains no repetitive amino acid or sugar units.

Ciguatoxin: isolation and chemical nature.

Ciguatoxin, the agent responsible for ciguatera, a disease produced in humans from ingestion of certain fishes, has been isolated from specimens of the moray eel, Gymnothorax javanicus. The toxin is apparently a lipid containing quaternary nitrogen, hydroxyl, and carbonyl functions.

Adult Niemann-Pick disease: its relationship to the syndrome of the sea-blue histiocyte.

Three unrelated female patients with adult Niemann-Pick disease are described. All the patients had reduced coagulation factors and involvement of the marrow, liver, spleen and lungs. Two patients were shown to have abnormal platelet function; two patients also had pingueculas and a late onset of a menarche. Foam cells and sea-blue histiocytes were seen in the marrow and livers in all three patients, in the spleen in two patients in the lymph nodes in one patient. The clinical presentation, the histologic appearance, the histochemical staining reactions, the lipid analysis and the ultrastructure were all consistent with a diagnosis of adult Niemann-Pick disease. On the basis of these observations, it is clear that adult Niemann-Pick disease is a cause of the syndrome of the sea-blue histiocyte. The existence of the syndrome of the sea-blue histiocyte as a separate entity is also questioned.

Proposal for standardized criteria for the diagnosis of benign, borderline, and malignant hepatocellular lesions arising in chronic advanced liver disease.

Although current literature contains many cases of putative premalignant hepatocellular proliferations and small hepatocellular carcinomas, no consistent nomenclature and diagnostic criteria have been put forward to describe them. These nodules, which are being detected by radiographic techniques in cirrhotic livers and removed during transplantation procedures, represent a new and challenging histologic spectrum of liver pathology. In this study, a multinational panel of five liver pathologists reviewed 23 such nodules and were able to reach a consensus on the diagnostic criteria and to devise a standard nomenclature to describe the histologic lesions. We recommend that benign nodules showing little histologic difference from cirrhotic nodules be classified as regenerative or macroregenerative, and nodules with atypical features not diagnostic of carcinoma be classified as borderline. Such standardization should facilitate further study of the pathologic features and clinical behavior of these lesions.

Isolation and structure/activity features of halomon-related antitumor monoterpenes from the red alga Portieria hornemannii.

Ten halogenated monoterpenes (2-6 and 8-12) related to the novel antitumor compound halomon (1) or to the carbocyclic analog 7 have been isolated from different geographic collections of the red alga, Portieria hornemannii. Structures were assigned to the basis of spectral analyses (primarily NMR and MS). The absolute configuration of isohalomon (2) was further established by X-ray crystallography. The compounds were comparatively evaluated alongside 1 and 7 in the U.S. National Cancer Institute's in vitro human tumor cell line screening panel. The results provide some interesting initial insights into the structure/activity relationships in this series.

Ludwig Symposium on biliary disorders--part II. Pathologic features and evolution of primary biliary cirrhosis and primary sclerosing cholangitis.

Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) share many clinical and pathologic features. Central to the symptoms and biochemical alterations of both conditions is a substantial loss of intrahepatic bile ducts, leading to interference with bile flow. This pathologic change may ultimately result in cirrhosis of the biliary type. In addition, however, biopsy specimens usually show an element of liver-cell destruction and associated inflammation, mainly interface hepatitis. This finding is more pronounced in PBC than in PSC but can lead in both diseases to features that resemble those of cirrhosis as a result of hepatitis virus infection. The resemblance often leads to diagnostic confusion, which is easily overcome by attention to the clinical, radiologic, serologic, and biochemical context. Histologic staging of PBC and PSC has led to a greater appreciation of their evolution but is hampered in biopsy material by sampling error. Examination of explanted livers at transplantation has demonstrated a wide variation in the maturation of lesions in various parts of the organ.

Multicentre randomized placebo-controlled trial of ursodeoxycholic acid with or without colchicine in symptomatic primary biliary cirrhosis.

AIM: To establish the efficacy of combination therapy with ursodeoxycholic acid (UDCA) and colchicine in patients with symptomatic primary biliary cirrhosis (PBC), defined by the presence of liver cirrhosis, pruritus or bilirubin exceeding 2 mg/mL. METHODS: A total of 90 patients were randomly assigned to ursodeoxycholic acid 500 mg/daily plus placebo (UDCA group, n=44), or ursodeoxycholic acid at the same dosage plus colchicine, 1 mg/daily (UDCA/C group, n=46). The two groups were comparable for age, sex, stage of disease, severity of pruritus, bilirubin, and Mayo score. All patients underwent clinical, ultrasonographic, and biochemical examinations at entry and then every 6 months up to 3 years of follow-up. Patients with cirrhosis underwent endoscopy every 12 months. In a sub-group of patients without cirrhosis, who consented, liver biopsy was repeated at the end of the study. RESULTS: The number of treatment failures (i.e. dead, orthotopic liver transplantation (OLT), complications of cirrhosis, doubling of bilirubin, untreatable pruritus) was 11 (25%) in the UDCA group and four (9%) in the UDCA/C group (P < 0.05). No significant differences were observed in terms of improvement of liver enzymes related to cholestasis and cytolysis and of amelioration of pruritus. The Mayo score values increased less above the baseline values at 24 and 36 month-intervals in the UDCA/C group than in the UDCA group. Histological evaluation at baseline and at the end of the study was available for 15 patients with pre-cirrhotic stage. A significant reduction in histological grading score was observed in patients from the UDCA/C group, whereas no changes in these histological scores were observed in the UDCA group. CONCLUSIONS: The addition of colchicine to ursodeoxycholic acid in patients with symptomatic primary biliary cirrhosis results in a small but significant reduction of disease progress.

Recombinant alpha 2B interferon (IFN) in the treatment of chronic hepatitis C disease in thalassaemia major (TM).

Hepatitis C virus (HCV) is responsible for the majority of cases of post transfusion non-A non-B (NANB) hepatitis in thalassaemia major (TM). Fifteen multi-transfused TM patients with serological, biochemical, histological and molecular biological evidence of HCV infection have been treated for six months with recombinant alpha interferon (IFN). Eleven (73%) responded, 8 (53%) had complete response (CR), 3 (20%) partial response (PR) and 4 (27%) did not respond (NR) to IFN. Natural killer (NK) cell activity 24 hours after the first dose of IFN was significantly increased in responders as compared to non-responders. Liver histology showed an overall reduction of portal inflammation and periportal necrosis in the responding patients. HCV RNA disappeared from serum in 8 (15) responders and partial responders. Non responders remained positive. HCV RNA was tested and found to be positive in liver tissue material in 7 patients, five of those were re-tested after IFN treatment. Two became negative (both CR) 3 remained positive despite biochemical response to IFN. The degree of induction of peripheral blood mononuclear cell 2'5' oligoadenylate synthetase messenger RNA (2-5 OAS mRNA), an enzyme induced by IFN, after the first dose of IFN did not correlate with response neither was any significant interaction with cytokines observed; tumour necrosis factor (TNF), interleukin-1. (IL-1) and CD4:CD8 ratios did not change. We conclude that IFN should be given to all TM patients with chronic active hepatitis due to HCV.

Thapsigargin, a histamine secretagogue, is a non-12-O-tetradecanoylphorbol-13-acetate (TPA) type tumor promoter in two-stage mouse skin carcinogenesis.

Thapsigargin, a hexaoxygenated tetraacylated sesquiterpene lactone, induced irritation of mouse ear and histidine decarboxylase (HDC) activity in mouse skin, but it did not induce ornithine decarboxylase in mouse skin or adhesion of human promyelocytic leukemia (HL-60) cells. Although thapsigargin did not give consistent positive results in a short-term screening system for tumor promoters, it was tested in a two-stage carcinogenesis experiment on mouse skin. The potency of thapsigargin to induce HDC in mouse skin was used to determine the dose in this experiment. Application of 10 micrograms (17 nmol) thapsigargin induced HDC activity of 139 pmol CO2/mg protein per 60 min. Tumors were found in the skin of 53.5% of the mice treated with DMBA plus 5 micrograms (8.5 nmol) thapsigargin in week 22, in none of those treated with thapsigargin alone by week 30. One tumor appeared in 1 of 15 mice treated with DMBA alone in week 21. Thapsigargin cannot bind to the phorbol ester receptor in the particulate fraction of mouse skin and so is classified as a non-12-O-tetradecanoylphorbol-13-acetate (TPA) type tumor promoter. It is a new tumor promoter differing in many respects from the well-defined TPA type tumor promoters. Several naturally occurring analogues of thapsigargin, such as thapsigargicin and thapsitranstagin, might also be new non-TPA type tumor promoters, because thapsigargicin and thapsitranstagin induced irritation of mouse ear and HDC activity in mouse skin.

Oxyphilic granular hepatocytes. Mitochondrion-rich liver cells in hepatic disease.

In the course of examining liver biopsy specimens, certain larger than normal liver cells whose cytoplasm is finely granular and strikingly acidophilic have been seen. These cells are called "oxyphilic granular hepatocytes" (oxyphils) because of their similarities to the "oncocytes" of the salivary glands and other endocrine organs. Oxyphilic liver cells can be readily differentiated from acidophilic bodies and groundglass hepatocytes by light and electron microscpy, the latter showing them to be extraordinarily rich in mitochondria. A retrospective study of 214 consecutive liver biopsies was undertaken to determine the prevalence of oxyphilic cells in a variety of liver diseases. Oxyphils were identified in 15% of the biopsy specimens, and were most strongly associated with chronic active hepatitis and cirrhosis in hepatitis B surface antigen (HBsAg)-positive patients. Subsequent reevaluation of 77 biopsy specimens from HBsAg-positive patients showed oxyphils in 28.6%. Their pathogenesis and significance in chronic liver disease are unknown.

Variation in subcapsular liver structure and its significance in the interpretation of wedge biopsies.

Wedge biopsies from the inferior border of the normal liver were studied in 72 cases. They were divided into three groups according to the extent and degree of capsular and subcapsular fibrous tissue. The changes were not sufficiently severe or extensive to cause confusion with nodular cirrhosis or to make wedge biopsy unreliable as a diagnostic tool.

Pre-eclampsia presenting with deep jaundice.

Pre-eclampsia complicated by deep jaundice occurred in a previously healthy primigravida. The main aetiological factor was disseminated intravascular coagulation; this caused both haemolysis and liver cell necrosis. Liver biopsy showed fibrin thrombi in the capillaries with microhaemorrhages and loss of periportal liver cells. The jaundice was attributed to both haemolytic and hepatocellular processes. Organs other than the liver were relatively unaffected.

Orcein staining of hepatitis B antigen in paraffin sections of liver biopsies.

Liver biopsies from 97 hepatitis B antigen (HBsAG)-positive patients were stained by a modified orcein method described by Shikata et al (1974) in order to detect the antigen in liver tissue. The results were consitently negative in acute hepatitis, but positive in nearly two-thirds of biopsies from 53 patients with chronic liver disease. The distribution of positive staining was frequently irregular so that there is a problem of sampling error in needle biopsies. The deposits were seen in the cytoplasm of liver cells and occasionally in Kupffer cells, but never in nuclei. There was an inverse relationship between staining and parenchymal necrosis. Biopsies from asymptomatic HB(s)Ag carriers were often strongly positive, as were "ground-glass" hepatocytes in carriers and patients with chronic liver disease. The mechanism of staining is unclear but may be related to the presence of disulphide bonds in (HBsAG. The technique is simple and of use both in fresh and stored material.

Clinical and histological features of delta infection in chronic hepatitis B virus carriers.

One hundred and six consecutive chronic hepatitis B virus (HBV) carriers were studied for the prevalence of delta markers in serum and tissue, and the clinical and histological features of those with and without delta infection were compared. Twenty (18.9%) patients were positive for anti-delta in serum or delta antigen in the liver or both. They presented at a younger age (30.3 v 38 years). All of them were symptomatic at the time of biopsy, in contrast to 35% of patients without delta infection who were not symptomatic. Those with delta infection had higher serum transaminase values and showed more severe liver damage on biopsy: chronic active hepatitis in 45% and cirrhosis in 55%. There was more pronounced disease activity both within the parenchyma and in the portal and periportal zones. The histological diagnosis of the 86 patients without delta infection included minimal disease (10%), chronic persistent hepatitis (9%), chronic active hepatitis (62%), and cirrhosis (19%). Delta infection in chronic HBV carriers is associated with a more active and progressive liver disease.

Histological demonstration of copper and copper-associated protein in chronic liver diseases.

Liver copper concentrations in percutaneous biopsy specimens were measured by neutron activation analysis and compared with histological staining for copper by rubeanic acid and rhodanine, and with copper-associated protein stained by orcein. Liver copper concentrations were elevated in 31 of 35 biopsies from patients with primary biliary cirrhosis (PBC), and discrimination between normal and elevated liver copper was correct in 32 of the 35 biopsies by staining with rubeanic acid, and 31 of the 35 by staining with rhodanine. Orcein staining of copper-associated protein was positive in 33 of the 35 biopsies. All 17 biopsy specimens from patients with Wilson's disease had high liver copper concentrations, but only nine had positive staining for copper, and six were orcein positive. Similarly, histological stains gave little indication of the liver copper concentrations in tissue from 16 patients with chronic active hepatitis. Staining of liver sections can be useful in detecting elevation of liver copper in PBC, but not in Wilson's disease, where the absolute concentration must be measured. Excess copper appears to accumulate in the liver in different chemical forms in PBC and Wilson's disease.

Serum glutamate dehydrogenase is not a reliable marker of liver cell necrosis in alcoholics.

Serum glutamate dehydrogenase (EC 1.4.1.3.) activity was measured in 73 hospital patients who had a history of chronic alcohol abuse and who all had a liver biopsy performed. High levels of serum GDH activity occurred in those patients with recent excess alcohol consumption independently of the underlying liver histology, and did not discriminate between those patients with and those without alcoholic hepatitis.

Is copper hepatotoxic in primary biliary cirrhosis?

In primary biliary cirrhosis (PBC) liver copper retention occurs as a complication of cholestasis. By analogy with Wilson's disease, it has been suggested that copper retention is hepatotoxic in PBC, and this has been the rationale for the use of D-penicillamine in this disease. The hypothesis that copper is hepatotoxic in PBC has not been tested and in this study we have evaluated the role of liver copper retention in the pathogenesis of PBC. Sixty-four patients with PBC have been studied. Fifty-four had increased liver copper concentrations. Liver cell synthetic function was well preserved. All the patients had normal prothrombin times, and only two had subnormal serum albumin concentrations. There was no correlation between liver copper concentrations and the degree of liver cell damage assessed biochemically (aspartate transaminase), and histologically. Electron microscopy was performed on liver biopsies from five patients with markedly increased liver copper concentrations. The liver cell ultrastructure was compatible with cholestasis. Liver cells contained electron dense lysosomes, which were shown to contain copper and sulphur by x-ray probe microanalysis. The characteristic organelle changes associated with copper toxicity in Wilson's disease were not observed. The biochemical, histological, and histochemical differences between PBC complicated by liver copper retention, and Wilson's disease, indicates that there are differences in the handling of copper in these disease. In this study we could find no evidence to suggest that copper plays an important role in the pathogenesis of liver dysfunction in PBC.

Immunological and histological studies in primary biliary cirrhosis.

Thirty-one patients with primary biliary cirrhosis in whom adequate histological liver material was available were studied by immunological and histological methods. There was no statistically significant correlation between individual histological features and the level of serum mitochondrial antibodies. A relationship between the duration of symptoms and histological stage of the disease supports the present concept of its evolution. However, several stages were often identified in the same specimen. Four cases with negative mitochondrial antibodies were similar to the other 27 clinically and histologically.