TP53 mutations and hepatocellular carcinoma: insights into the etiology and pathogenesis of liver cancer.

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and the major risk factors include chronic infections with the hepatitis B (HBV) or C (HCV) virus, and exposure to dietary aflatoxin B(1) (AFB(1)) or alcohol consumption. Multiple genetic and epigenetic changes are involved in the molecular pathogenesis of HCC, for example, somatic mutations in the p53 tumor suppressor gene (TP53) and the activation of the WNT signal transduction pathway. AFB(1) frequently induces G:C to T:A transversions at the third base in codon 249 of TP53 and cooperates with HBV in causing p53 mutations in HCC. The detection of TP53 mutant DNA in plasma is a biomarker of both AFB(1) exposure and HCC risk. Chronic infection with HBV and HCV viruses, and oxyradical disorders including hemochromatosis, also generate reactive oxygen/nitrogen species that can both damage DNA and mutate cancer-related genes such as TP53. Certain mutant p53 proteins may exhibit a 'gain of oncogenic function'. The p53 biological network is a key responder to this oxidative and nitrosative stress. Depending on the extent of the DNA damage, p53 regulates the transcription of protective antioxidant genes and with extensive DNA damage, transactivates pro-oxidant genes that contribute to apoptosis. The X gene of HBV (HBx) is the most common open reading frame integrated into the host genome in HCC and the integrated HBx is frequently mutated. Mutant HBx proteins still retain their ability to bind to p53, and attenuate DNA repair and p53-mediated apoptosis. In summary, both viruses and chemicals are implicated in the etiology of TP53 mutations during the molecular pathogenesis of HCC.

Chlamydospore formation on Staib agar. Observations made before Candida dubliniensis was described.

When routinely using Staib agar to detect Cryptococcus neoformans in AIDS patients by the brown colour effect of its colonies, rough-looking colonies of a questionable variety of Candida albicans were also found. Microscopically, these colonies consisted of pseudohyphae with abundant masses of chlamydospores. However, the colonies of C. albicans were smooth-edged and formed by round-oval blastospores only. Such observations were made during the mycological supervision of 36 cryptococcosis cases during the 1987-94 period. All these questionable cultures of Candida spp. were discarded. However, because the corresponding photographs of and records on such strains were found to be identical with those recently published by molecular biologists under the title 'Chlamydospore formation on Staib agar as a species-specific characteristic of Candida dubliniensis' [Staib, P. & Morschhäuser, J. (1999) Mycoses 42, 521-524], the present communication presents a report on such observations in a representative and exemplary case of an AIDS patient.

Green and brown colour effects in tremellaceous yeast fungi on Staib agar.

Fifty-eight species of basidiomycetous yeast fungi were examined for green and brown colour effects (GCE, BCE) on Staib agar (Guizotia abyssinica creatinine agar). In addition to 9% of Cryptococcus laurentii strains tested, only Cryptococcus podzolicus was GCE-positive. Out of 14 strains of this species, 13 showed a GCE and four showed a BCE. All GCE-positive strains utilized creatinine and creatine as a source of nitrogen but not of carbon. None of these strains could grow at 37 degrees C. Unlike Cr. laurentii, no strains of Cr. podzolicus assimilated glycine as a source of carbon. No association was found to exist between GCE and killer activity. Some tremellaceous creatinine-negative species (Cryptococcus gastricus) showed a BCE whereas some sporidiobolaceous creatinine-positive yeasts (Leucosporidium, Rhodotorula) produced neither GCE nor BCE.

The green colour effect (GCE) of the killer strain Cryptococcus laurentii CBS 139 on Staib agar.

Attention is drawn to the observation that the type strain Cryptococcus laurentii CBS 139, producing killer toxins (mycocins) directed at Cr. neoformans var. gattii, causes a green colour effect (GCE) on Staib agar (Guizotia abyssinica creatinine agar) in combination with an intense assimilation of creatinine. Five (9.6%) out of 52 strains of Cr. laurentii of various origin, showed a GCE and intense creatinine assimilation. Further research must show if all Cr. laurentii strains, characterized by a GCE similar to that of the strain CBS 139, are also capable of producing killer toxins. For further ecological and epidemiological research on strains producing killer toxins directed against species of the genus Cryptococcus, it is proposed to use Staib agar as differential culture medium indicating both colour effects, i.e. the GCE and the brown colour effect (BCE).

No evidence of significant activity of the multidrug resistance gene product in primary human breast cancer.

BACKGROUND: The discovery of the multidrug resistance (MDR1) gene product P-glycoprotein (P-gp) has been widely seen as an important milestone in our understanding of the mechanisms underlying the clinical phenomenon of the emergence of resistant cells. MDR1 expression has been shown for numerous solid tumors and for virtually all hematologic malignancies. Nevertheless, results regarding MDR1/P-gp expression in human breast cancer have been controversial and the results of clinical trials on modulation of P-gp activity have not been encouraging. PATIENTS AND METHODS: MDR1/P-gp expression and the function of the P-gp pump were investigated in 61 tumor samples from patients with primary breast cancers by multiparameter analysis using MDR1-RT-PCR, immunohistochemistry with two MAbs (UIC2 and MRK16) and the rhodamine 123 (Rh123) efflux assay. The cellular composition of the tumor cell suspension was analyzed by using specific MAbs against the P-gp expressing lymphocyte subsets CD4, CD8 and CD56, as well as against the HER-2/neu gene product, which was used to identify breast carcinoma cells. RESULTS: UIC2 and MRK16 revealed a staining positivity in 72% and 75% of samples, respectively. A positive MDR1-RT-PCR signal was detected in 62% of the samples. Nevertheless, no correlation between immunohistochemistry and RT-PCR could be established. Furthermore, there was no correlation between HER-2/neu expression and MDR1-RT-PCR or P-gp immunohistochemical assays. A contamination by CD8+ and CD4+ lymphocytes was established in 100% and 84% of tumor cell suspensions, respectively. As assessed by the Rh123 efflux assay CD8+ and the CD4+ lymphocytes exhibited marked P-glycoprotein activity, whereas such activity was not detectable in a single instance for the breast carcinoma cells. In MDR1-RT-PCR positive samples, contamination by CD8 lymphocytes averaged 4.3%, while the contamination of CDS cells in the MDR1 mRNA-negative samples was only 2.4% (P = 0.007). This signal vanished after elimination of the lymphocyte subpopulations by T-cell rosetting. CONCLUSIONS: In primary breast cancer detection of MDR1 gene expression by means of RT-PCR or immunohistochemical assays is not indicative for the MDR phenotype, since there is no evidence of significant activity of the P-gp pump.

Mycological control and surveillance of biological waste and compost.

This paper presents some recent developments regarding current work on hygienic aspects, in particular the presence and dispersion of fungi (e.g. Aspergillus fumigatus), of biological waste and compost.

[Disseminated cryptococcosis with extensive cutaneous involvement in AIDS]. / Disseminierte Kryptokokkose mit ausgeprägtem Hautbefall bei AIDS.

BACKGROUND: Diagnosis of an ulceratively decaying indolent papule in the skin of an AIDS patient. CASE REPORT: In a 36-year-old HIV-positive man with a CD4 lymphocyte count of 60/microliters, a diagnosis of disseminated cryptococcosis was established based on a biopsy of an ulceratively decaying indolent papule in the skin of the left side gluteal region. In additional papulopustular skin lesions of neck, upper arm, upper thigh, and rima ani, Cryptococcus neoformans var. neoformans was detected by specific culture. The Cryptococcus neoformans antigen titre in serum was 1:160. The extensive cryptococcal skin involvement was accompanied by symptoms of meningeal cryptococcosis like hearing at an abnormal sound volume, a sensation of high pressure in the head and a change of behaviour, but absence of cephalgia and stiff neck. Attention is drawn to the importance of biopsy for the differential diagnosis of the skin lesions and to the significance of a specific cultural detection of Cryptococcus neoformans in view of the therapy and epidemiology of this mycosis. Under a combination therapy, consisting of amphotericin B, flucytosine and fluconazole, a healing of the skin lesions and disappearance of the neurological symptoms followed by negative cultural and serological tests were seen. Specific comments on the epidemiology of cryptococcosis in AIDS are made. CONCLUSION: In case of doubt, papulopustular skin lesions of HIV-positive patients should be biopsied. Cryptococcosis should also be considered.

Pathological and epidemiological aspects of skin lesions in histoplasmosis. Observations in an AIDS patient and badgers outside endemic areas of histoplasmosis.

As a consequence of HIV infection, histoplasmosis is increasingly occurring as an opportunistic infection with a systemic course outside histoplasmosis-endemic areas, e.g. in Europe. Accordingly, questions concerning the epidemiology of this mycosis arise. Two incidents involving histoplasmosis in man and badgers with prevailing involvement of the skin encouraged us to review the pathogenesis and epidemiology of this mycosis in Germany, where so far Histoplasma capsulatum has not been endemic. With a view to prevention, attention is drawn to the avoidance of microfoci of H. capsulatum in the newly introduced concept of biowaste and its composting plants in countries with modern waste management.

Co-infection by Cryptococcus neoformans and Mycobacterium avium intracellulare in AIDS.

In the observation of various opportunistic pathogens in HIV-positive persons, co-infection by Cryptococcus neoformans together with Mycobacterium avium intracellulare was found if there was a CD4 lymphocyte count as low as 3-20 microl. In 1540 HIV-positive patients under treatment at a Berlin hospital (Auguste-Viktoria-Krankenhaus) during 1985-1994, all AIDS-relevant diseases were examined in a multivariate analysis as variables of influence on the manifestation of a systemic Mycobacterium avium complex (MAC) infection. The analysis involved data on 36 cases of cryptococcosis and 202 cases with a typical clinical course in whom MAC had been detected at sterile body sites. As significant and independent factors of influence, the following were identified: C. neoformans infection, wasting syndrome, lower age, low CD4 lymphocyte count and preceding Pneumocystis carinii pneumonia (PcP) prophylaxis. Cryptococcosis ranged first with an odds ratio of 2.75. The concomitant manifestation of cryptococcosis and systemic MAC infection in six patients is shown. Because both opportunists, C. neoformans and avian mycobacteria, may have their common habitat in droppings of defined species of pet birds, a common source of infection deserves further clinical and epidemiological attention.

Co-infection by Cryptococcus neoformans and Mycobacterium avium intracellulare in AIDS. Clinical and epidemiological aspects.

In the observation of various opportunistic pathogens in HIV-positive persons, co-infection by Cryptococcus neoformans together with Mycobacterium avium intracellulare was found if there was a CD4 lymphocyte count as low as 3-20/microliters. In 1540 HIV-positive patients under treatment at a Berlin hospital (Auguste-Viktoria-Krankenhaus) during 1985-1994, all AIDS-relevant diseases were examined in a multivariate analysis as variables of influence on the manifestation of a systemic Mycobacterium avium complex (MAC) infection. The analysis involved data on 36 cases of cryptococcosis and 202 cases with a typical clinical course in whom MAC had been detected at sterile body sites. As significant and independent factors of influence, the following were identified: C. neoformans infection, wasting syndrome, lower age, low CD4 lymphocyte count and preceding Pneumocystis carinii pneumonia (PcP) prophylaxis. Cryptococcosis ranged first with an ods ratio of 2.75. The concomitant manifestation of cryptococcosis and systemic MAC infection in six patients is shown. Because both opportunists, C. neoformans and avian mycobacteria, may have their common habitat in droppings of defined species of pet birds, a common source of infection deserves further clinical and epidemiological attention.

Cryptococcosis in HIV infection of man: an epidemiological and immunological indicator?

Cryptococcosis is an epidemiological and immunological indicator due to the absence of Cryptococcus neoformans as a saprophyte in immunocompetent humans and the advantage of specific C. neoformans culture. On this basis, a report is presented on the CD4 lymphocyte count of 36 AIDS patients suffering from cryptococcosis and other concomitant or missing opportunistic AIDS-defining infections. In 26 out of 36 patients, i.e. 72%, a CD4 lymphocyte count of < or = 50/microL (mean value 39.5%) was found. Cryptococcosis as the sole opportunistic infection was diagnosed in 5 cases (13.9%). In 31 cases, various combinations of AIDS-associated diseases were found: Pneumocystis carinii pneumonia (PCP) (n = 19), cytomegalovirus infection (CMV) (n = 10), Kaposi's sarcoma (n = 6), Mycobacterium avium intracellulare infection (MAI) (n = 5), pneumonia (n = 2), toxoplasmosis (n = 2), Candida esophagitis (n = 1), tuberculosis (n = 1), lambliasis (n = 1), salmonellosis (n = 1) and wasting syndrome (n = 5). The conspicuous simultaneous occurrence or succession of pneumocystosis and cryptococcosis and the contrasting absence of aspergillosis and mucormycosis (zygomycosis) are commented. Based on the present observations in HIV-infected persons in Berlin, a CD4 lymphocyte count of < 150/microL may be used as a parameter indicating a predisposition for cryptococcosis as an airborne AIDS-defining infection. Attention is drawn to bird droppings as the sole habitat of C. neoformans and accidental niche of various other microorganisms.

Brown-red pigment formation by the mycelial phase of a clinical isolate of Histoplasma capsulatum on Staib agar. A preliminary report.

In an HIV-positive patient, the suspected diagnosis of histoplasmosis capsulatum (being the first opportunistic infection indicating AIDS) on the basis of histopathological findings in biopsy material could be proved by culture on Staib agar (syn. Guizotia abyssinica creatinine agar, bird seed agar, etc.). On Staib agar, after 4 weeks at 26 degrees C, there was a cockade-like colony growth, consisting of a white centre, followed by a brown-red pigmented zone surrounded by a border of submerged mycelial growth of tan to brownish colour. Morphologically, there was a moderate formation of tuberculate macroconidia and a heavy formation of microconidia. On neutral Sabouraud's dextrose agar, there was a colony formation without pigment (albino type) free of tuberculate macroconidia and microconidia. Proposals for further investigation of these preliminary observations are made.

[Fungi in the home and hospital environment]. / Pilze im Wohn- und Krankenhausmilieu.

From the viewpoint of 40 years of experience in the field of medical mycology with the help of current topics the competence of the medical mycologist for evaluation of a presence of fungi in the home and hospital environment is commented. The topics considered are as follows: 1. The HIV-infected person and the habitat of Cr. neoformans; the predisposition for cryptococcosis and the CD4 lymphocyte count. 2. Invasive aspergillosis after heart transplantation; by exemplary cooperation between the heart surgeon and the medical mycologist it could be demonstrated that the frequently fatal invasive aspergillosis can be avoided. 3. Attention is drawn to the currently most interesting habitats of fungi in the home environment, i.e., biological waste and compost. It has been shown that among the various fungi, the causative agents of systemic mycoses may also be found.

CD4 lymphocyte count in HIV-positive persons exposed to Cryptococcus neoformans.

A report is presented on four HIV-positive homosexual men examined after several months of exposure during cleaning of a flat from masses of pigeon droppings heavily colonized by Cryptococcus neoformans. Only one out of the four persons, with a CD4 lymphocyte count of 50/microL, fell sick from systemic cryptococcosis, but not the others, with CD4 lymphocyte counts of 180, 250, and 630/microL, respectively; they remained clinically and mycologically inconspicuous and free from C. neoformans. Open questions in view of the epidemiology of opportunistic pathogens in AIDS are discussed with regard to the CD4 cell count as a parameter indicating a predisposition for cryptococcosis as an airborne AIDS-defining opportunistic infection. This has been confirmed by specific cultural diagnosis of the agent in both the environment and the patient. Already in 1987/88, the probable source of infection had been the subject of epidemiological studies on C. neoformans in Berlin.

Diversity of DNA fingerprints in Cryptococcus neoformans.

DNA fingerprint patterns of 156 Cryptococcus neoformans isolates (26 AIDS patients, 46 non-AIDS patients, and 40 environmental sources) from both varieties (126 C. neoformans var. neoformans and 30 C. neoformans var. gattii isolates) and from seven countries were analyzed by using the DNA probe UT-4p. Nine and twelve distinct DNA fingerprint patterns were observed for isolates of the C. neoformans var. neoformans and var. gattii, respectively. No pattern was unique to AIDS patients, non-AIDS patients, or the environment. Pattern II was observed more often in non-AIDS patients (8 of 23) than in AIDS patients (0 of 25). Pattern V was the most prevalent pattern (42 of 82) in clinical and environmental isolates. Isolates from three AIDS patients in Burundi and Zaire exhibited patterns identical to each other but different from those of isolates collected from their houses (i.e., dust of floors, walls, etc.) or a nearby pigeon coop. DNA fingerprint stability was determined for 53 isolates from nine non-AIDS patients at different time intervals during 5 to 128 weeks of antifungal therapy. For eight patients, the fingerprint pattern was stable while the ninth may have had a mixed infection. Pattern II was observed in 4 of 9 patients, which is similar to 4 of 14 in other non-AIDS patients as reported here. In spite of the extensive pattern heterogeneity among 15 C. neoformans var. gattii isolates in Australia, the patterns observed in seven California isolates were quite different from those in Australia. Among isolates of C. neoformans var. gattii, one fingerprint pattern (designated b) was observed in several countries of the Far East. The fingerprint patterns of two of three environmental isolates from Eucalyptus camaldulensis trees in Australia were identical to those of 2 of the 12 clinical isolates from the country.

Evidence of canary droppings as an important reservoir of Cryptococcus neoformans.

After preliminary results had shown the occurrence of Cryptococcus neoformans in canary droppings in southern Italy, the increasing epidemiological interest in cryptococcosis and the habitats of the agent led to more extensive studies. 180 samples of canary droppings were collected from pet shops and private households in two towns (Messina and Reggio Calabria) of southern Italy and culturally examined for C. neoformans. The examination was carried out with the help of the brown colour effect (BCE) specific of the C. neoformans colony on Guizotia abyssinica creatinine agar (Staib agar). 48 samples (26.6%) were positive; of these, 32/108 (29.6%) were from pet shops and 16/72 (22.2%) from private households. The colony growth was not mucous, i.e. microscopically the blastospores were found to be little or not encapsulated. All C. neoformans strains tested by the auxanographic method showed a weak assimilation of creatinine. The variety status of the isolates was tested with canavanine-glycine-bromothymol-blue (CGB) agar; all strains tested (n = 420) were found to be C. neoformans var. neoformans. In the light of extensive studies on C. neoformans and the canary in the pre-AIDS era in Germany, the present observations in Italy ask for further basic research, epidemiological studies, and education of the public.

[Histoplasmosis of the skin as an initial opportunistic infection in AIDS]. / Histoplasmose der Haut als opportunistische Erstinfektion bei AIDS.

A 55-year-old homosexual Indonesian (last stay in Indonesia 2 years previously), known to be HIV positive since 1986, developed desquamating, in part ulcerating, skin eruption over the face and shoulder region. On admission his temperature was 38.2 degrees C, erythrocyte sedimentation rate 72/95 mm, white cell count 3.100/microliters, and the CD4 cell count 30/microliters. Examination of lung, oesophagus, stomach, duodenum and colon for possible opportunistic infections was negative. Fundoscopy revealed an infiltrate in the right eye with destruction of the vitreous. Skin biopsy suggested histoplasmosis, confirmed by culturing H. capsulatum varietas capsulatum. It is likely that this was the reactivation of a latent, previously symptom-free infection, in this case the first opportunistic infection in the presence of AIDS. For 30 days he received infusions of amphotericin B (initially 0.1 mg/kg daily, after the 5th day 0.5 mg/kg), resulting in rapid healing of the skin lesions. Subsequently he has received (for 6 months so far) itraconazole, 400 mg daily, without further complications.