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Biomedical subjects

L Bianchi

Publications and source records attributed to L Bianchi.

At least 271 records · Page 15Linked to original sources
PubMed1990

Decreased hepatocellular volume and intact morphology of tight junctions in calcium deprivation-induced cholestasis. Stereological and multiple indicator dilution analysis.

Cholestasis induced by perfusion of the liver with hypocalcemic media has been ascribed to several defects in bile secretion including increased biliary permeability. To investigate this model of cholestasis further, livers perfused with hypo- and normocalcemic media were examined stereologically using thin sections and freeze-fracture replicas. Organization of tight junctions was not altered by hypocalcemia; neither the number of strands nor the junctional depth were significantly affected. By contrast, the volume of hepatocytes decreased by 11% (p less than 0.001), compensated for by an increase in the space of Dissé and of the sinusoids. The canalicular length decreased by 25% (p less than 0.01), while the canalicular membrane surface was not altered. Multiple indicator dilution studies confirmed a decrease in hepatocellular volume, measured as the water space by 14% (p less than 0.03). This was compensated for by an increase in the extravascular sucrose, but not the albumin space. Immediately after switching from normo- to hypocalcemic perfusate a K+ efflux of 62 mumol/g liver was observed corresponding to approx. 8% of the hepatocellular water space. Our results suggest that hypocalcemia-induced cholestasis is due, at least in part, to a disturbance of the osmotic equilibrium, possibly caused by impairment of an ion transport system involved in hepatocellular volume control.

Animals↗
PubMed1990

Photobiological effects in Saccharomyces cerevisiae induced by the monofunctional furocoumarin 4,4',6-trimethylangelicin (TMA) and the bifunctional furocoumarin 8-methoxypsoralen (8-MOP).

Recently, the monofunctional furocoumarin 4,4',6-trimethylangelicin (TMA) has been proposed for photochemotherapeutic use. In order to assess its genotoxic potential, the photobiological (genetic) effects of TMA were studied in a diploid strain of Saccharomyces cerevisiae (D7) and compared to those of the bifunctional furocoumarin 8-methoxypsoralen (8-MOP). At equimolar concentrations, the induction of lethal effects by TMA in the presence of equal 365-nm radiation was higher than that exerted by 8-MOP. TMA was also more active than 8-MOP in inducing nuclear events such as nuclear reverse mutation and mitotic recombination (crossing-overs and gene conversion) per unit dose of 365-nm radiation. At equal survival, however, TMA was less efficient in inducing reverse mutation and crossing-over, showing the same activity as 8-MOP in the induction of gene conversion. TMA was more active than 8-MOP in the induction of cytoplasmic 'petite' mutations per unit dose of 365-nm radiation and per viable cell. The high photobiological activity of this monofunctional furocoumarin is mainly related to its strong DNA photobinding but also to the type of monoaddition induced, to the sequential distribution in DNA and to the generation of active forms of oxygen.

Cell Survival↗
PubMed1990

Reduction of chromosomal damage by bleomycin in lymphocytes from subjects supplemented with carotenoids. Relevance in bleomycin tumour chemotherapy. Preliminary results.

In a one year-study, 9 healthy human donors were being supplemented with beta-carotene (BC) plus canthaxanthin (CX), to determine the effect of carotenoids on chromosomal damage (micronuclei) induced in the donors' lymphocyte cell cultures by exposure to bleomycin (BLM), an antineoplastic drug that has been shown to produce chromosomal aberrations through the production of free radicals. The first four months monitoring data, including determination of carotenoid blood levels, are here reported. These data show that carotenoid supplementation significantly decrease (up to 50%) the formation of micronuclei induced by BLM in human lymphocyte cell cultures. This decrease is in correlation with carotenoid blood levels.

Adult↗
PubMed1990

[Lyell's syndrome and lymphoma].

The authors present the case of a patient affected by Lyell's Syndrome and Lymphoma that was revealed in the post-mortem examination. At onset the disease showed mucosal hyperaemia, oedema and erosions. In about ten days macular lesions with vesciculation and bullae appeared on the abdomen. General conditions did not seem to be affected. Three weeks later a fever was noted. No important illness, nor drug assumption were detectable in the history of the patient. At the beginning of the fourth week a dramatic worsening occurred with erythrodermic state and high fever. Death occurred at the sixth week in spite of therapy. Bacteriological and virological examinations were always negative. Post-mortem examination showed retroperitoneal and pelvic neoplastic tissue, involving lumboaortic lymph nodes. Histopathology demonstrated a low grade malignancy non Hodgkin Lymphoma, diffused type with small lymphocytes showing plasmocytic differentiation. The lack of drug intake or infectious disease in the history, underlines the peculiar association between the tumor and the syndrome. Rare cases of TEN associated with lymphoproliferative neoplasm are reported in the literature, and the pathogenetic problem of the syndrome is reviewed.

Humans↗
PubMed1989

Distribution and peroxidative oxidation of 2-t-butyl-4-methoxyphenol in rat tissues after a single intraperitoneal dose.

The distribution of 2-t-butyl-4-methoxyphenol (BHA) and its conversion to 2,2'-dihydroxy-3,3'-di-t-butyl-5,5'-dimethoxydiphenyl (di-BHA) in rat tissues at different times (1-96 hr) following the intraperitoneal administration of a single dose of BHA (32 mg kg-1 body weight) were monitored by gas chromatography-mass spectrometry (GC/MS) analysis of both compounds. High BHA levels were found in the intestine and liver persisting up to 24 hours (5.5-20.7 and 1.8-3.3 micrograms g-1 wet weight, respectively). In these tissues, values of the area under the experimental concentration curve (AUC0-24) were 285 and 49 times higher, respectively, than those observed in plasma (945 ng mL-1 hr), AUC0-24 values in kidney, spleen, erythrocytes, and brain were 2-7 times higher, whereas values below those found in plasma were observed in lung and muscle. The metabolite di-BHA could be detected in the intestine, kidney, and spleen, amounting to 5-8% of BHA. These findings indicate that rat intestine is capable of transforming in vivo BHA into di-BHA even when the former compound is administered intraperitoneally and that this capacity is shared by the kidney and spleen.

Animals↗
PubMed1989

Diagnostic accuracy of fine-needle aspiration biopsy in patients with hepatocellular carcinoma.

The present study was undertaken to investigate the diagnostic usefulness of fine-needle aspiration biopsy (FNAB) in a large series of patients with hepatocellular carcinoma (HCC) seen over a 1-year period. During 1986, ultrasonographically guided percutaneous FNAB was performed in 72 patients with suspected HCC. A final diagnosis of HCC was made in 58 patients. The presence or absence of HCC was ascertained by histological examination and/or by other diagnostic procedures (alpha 1-fetoprotein, computed tomography, arteriography) and by clinical follow-up (repeated ultrasonographic controls) and/or by surgery or necropsy. A total of 61 FNABs were carried out in these 58 patients. Only 42 (69%) of the 61 FNABs allowed the diagnosis of HCC. This moderate diagnostic sensitivity was not related to tumor size. Only one false positive result was observed in the non-HCC group. Therefore, the diagnostic specificity of FNAB for HCC was 93%, with a positive predictive value of 97% and a negative predictive value of 40%. These results show that FNAB is a useful diagnostic technique in patients with HCC. However, these data also show that there is a large proportion (31%) of subjects with false negative results. Therefore, we suggest that further efforts should be made to improve the diagnostic accuracy of this procedure.

Adult↗
PubMed1989

Juvenile colloid milium. Immunohistochemical and ultrastructural studies.

A 7-year-old Italian girl with juvenile colloid milium was studied with histological, immunohistochemical, and electron microscopic methods. This patient had a well-documented history of severe sunburn and developed the lesions on the face shortly afterward. Numerous apoptotic keratinocytes were observed in the lower epidermis. These cells began their degeneration with filamentous whorl formation (or filamentous degeneration) of tonofilaments. In the papillary dermis the colloid substance was resolved by the electron microscopy into either wavy, thin filaments derived from the epidermal keratinocytes or typical amyloid filaments. Many desmosomes and gap junctions were found in the colloid substance. Polyclonal antikeratin antibody (DAKO) was positive in the colloid substance, particularly in the parts close to the epidermis. These findings suggested that juvenile colloid milium is different from adult colloid milium despite clinical similarities and that the former belongs to the group of actinic amyloid K, i.e. amyloidoses due to actinic degeneration of keratinocyte and its keratin.

Child↗
PubMed1989

Liver disease in rural Tanzania--a diagnostic approach.

In a prospective study on the aetiology of liver disease and its diagnostic approach in a District hospital in rural Tanzania, 48 consecutive patients with evidence of liver disorders were investigated by physical examination, biochemical tests, laparoscopy and histology. Liver cirrhosis (posthepatic, alcoholic) was found in 31%; non cirrhotic alcoholic liver disease in 15%; viral, bacterial and protozoal liver disorders in 33%, and neoplastic liver changes in 21% of all patients. Clinical impression alone coincided with the final diagnosis in 40% of all cases. This figure was increased to 46%, when haematological and biochemical results were included, and to 71%, when laparoscopy (without histology) was used in addition. Laparoscopy was particularly decisive in the diagnosis and further management of cirrhosis, liver abscess and neoplastic liver disorders. The additional information obtained from histology led to the final diagnosis. Histology was specially useful for the diagnosis of alcoholic liver disease, tropical splenomegaly syndrome and non specific reactive hepatitis. The usefulness of laparoscopy as a diagnostic tool in a district hospital is discussed.

Adolescent↗
PubMed1989

HLA antigens and infantile psoriasis.

The frequency distribution of HLA-A, -B, -C and -DR antigens in a group of 52 unrelated psoriatic patients, aged from 0 to 12 years, selected according the following four clinical subsets: guttate, inverted, follicular and minimal, was evaluated. A statistical analysis on 85 infantile psoriatic patients, randomly selected, and divided into two groups according to the age of onset of the disease, was also performed. The results show an increase of HLA-B27 antigen in the minimal psoriasis, A2 in the guttate form and of B41 allele in the inverted psoriasis. A significantly prevalence of CW6 antigen either in follicular subset or in total psoriatic patients or in both groups of age was observed, showing a strict association with the disease. An increase of HLA-B17, CW6 and DR6 in the total psoriatic patients was also noticed. The authors underline the prognostic value of this analysis.

Age Factors↗
PubMed1989

[Clinical variants of pachydermoperiostosis: complete, incomplete and atypical forms].

We describe two cases of pachydermoperiostosis, that, with the case that we have already published, allow us to present the complete clinical picture of the disease in the three forms: complete, incomplete and "forme fruste". It is interesting to note that the lack of an important symptom (digital clubbing or CVG) does not exclude the diagnosis but defines the clinical variant. The primitive hypertrophic osteoarthropathy is a common feature for the three patients, marked for I and III case, mild, but important from the diagnostic point of view, for the II case. The identification of a new marker of osteoblastic activity: osteocalcin blood level, is very important to determine the degree of activity of the disease. EM study, performed for the first time, shows an enhanced activity of the fibroblasts and a thickening of the basal membrane of the blood vessels. It is own opinion that the clinical picture observed, the vascular, the metabolic, the EM investigations give a further contribution to the understanding of this disease.

Adult↗
PubMed1989

[Cardiomyopathy due to adriamycin: the possibility of its prevention. Monitoring by noninvasive technics].

To prevent delayed cardiomyopathy induced by adriamycin and subsequent severe congestive heart failure, a monitoring schedule with noninvasive techniques to measure cardiac performance (CPK-MB, electrocardiographic, systolic time intervals, echocardiography and quantitative radionuclide angiography) has been used. 15 patients, 33 to 65 years old, with metastatic breast carcinoma, previously treated with a polychemotherapy protocol not including adriamycin have been studied. Monitoring at 0 time allowed to exclude one patient with previous asymptomatic cardiomyopathy and to treat patients at risk with cardiovascular pathology, up to reach and even exceed the dosage of 550 mg/m2. Four of the treated patients showed positive findings of cardiomyopathy at different adriamycin dosage levels: 2 asymptomatic dilatative cardiomyopathies, 1 symptomatic and 1 with congestive heart failure remitted with medical therapy. No patient died because of cardiovascular complications. The results obtained show that of all noninvasive techniques used, only quantitative radionuclide angiocardiography allowed, when employed following an adequate monitoring schedule, to detect reliable findings of moderate and reversible cardiomyopathy thus indicating the appropriate time for drug discontinuation.

Adult↗
PubMed1989

EEG and spectral analysis in HIV immunocompetent patients free from clinical CNS impairment. A follow-up study in 20 cases.

Twenty HIV immunocompetent subjects without neurological symptoms were studied by EEG and spectral EEG analysis over a period of 6-16 months. 40% of them showed mild diffuse changes in background activity on basal evaluation, but the appearance of neurological symptoms and the evolution of clinical picture seemed unrelated to the presence of aspecific EEG and spectral analysis changes. As most of them were oppiate abusers, these findings could be ascribed to the long-term drug use.

AIDS Dementia Complex↗
PubMed1988

The diagnostic significance of periportal hepatic necrosis and inflammation.

In this review the several types of cell damage and cell death which may be found in liver biopsy specimens are defined. We describe the different processes which occur at the portal/parenchymal or septal/parenchymal interface, viz. periportal spillover, periportal hepatitis, classic or lymphocytic piecemeal necrosis and biliary piecemeal necrosis. The diagnostic implications of these lesions in relation to the clinicopathological diagnosis and prognosis in various liver diseases are discussed.

Diagnosis, Differential↗
PubMed1988

Liver cirrhosis in histiocytosis X.

Cirrhosis of the liver was diagnosed in an 18-year-old man with histiocytosis X. Electron microscopy and immunohistochemistry revealed infiltration of the liver by the typical cellular elements of histiocytosis X. Endoscopic retrograde cholangiography showed alterations resembling those of sclerosing cholangitis. Sixteen months later, the patient died of recurrent variceal bleeding and cholangiosepsis. Autopsy confirmed that cirrhosis was the main manifestations of the underlying disease. Thus, cirrhosis of liver can be a main and potentially fatal manifestation of histiocytosis X beyond the pediatric age range. Histiocytosis X may lead to parenchymal infiltration of the liver and to changes of the major bile ducts resembling sclerosing cholangitis. The diagnosis of hepatic histiocytosis X can easily be missed without relying on appropriate electron microscopic and immunohistochemical investigations.

Adolescent↗
PubMed1988

Chemoprevention of indirect and direct chemical carcinogenesis by carotenoids as oxygen radical quenchers.

Beta-carotene (BC) and canthaxanthine (CX), two carotenoids with and without pro-vitamin A activity, respectively, were found to help to prevent benzo[a]pyrene (BP)-induced skin carcinogenesis in the dark and BP photocarcinogenesis (UV 300-400 nm) when given as an oral supplement to female Swiss albino mice. The same experimental procedure was adapted to 8-methoxypsoralen (8-MOP) photoinduction of mammary carcinomas in mice. Here also, the two carotenoids were strongly antitumorigenic. Indeed, 8-MOP photomutagenesis, tested in S. typhimurium TA 102, appeared to depend on a two-step reaction, namely an oxygen-independent DNA-8-MOP photoadduct, followed by an oxygen-dependent second step, sensitive to carotenoids. This result suggests that dietary carotenoids (powerful antioxidant molecules) might prevent the carcinogenic risk caused by substances that are transformed into ultimate carcinogens by oxidative processes which are indirectly carcinogenic. Finally, to verify whether supplemental carotenoids can affect carcinogenesis where neither light excitation nor oxidative metabolic processes are involved, an experimental attempt was made on gastric carcinogenesis induced in rats by the direct carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The results demonstrate that supplemental carotenoids do not affect initiation and progression stages, but do prevent the progression stage of dysplasias to infiltrating gastric carcinomas. Thus, this provides strong presumptive evidence for oxygen radical involvement in the later stages of this neoplastic development, as recently reported in the literature. As far as mutagenicity in S. typhimurium is concerned, carotenoids do not exert, as expected, any protective effect on MNNG mutagenic activity. The above experimental data suggest that supplemental carotenoids, instead of sunscreen preparations, can be adopted by outdoor workers to prevent skin cancer. Accordingly, such natural antioxidants may be useful in human chemoprevention against neoplasias of the lung, breast, urinary bladder, and colon and rectum even after radical surgery.

Animals↗