52 research outputs found
Hepatitis B : a light microscopical and immunohistochemical study
The findings reported in this thesis provide a basis for a strategy for anti-viral
treatment of chronic hepatitis B.
Theoretically several approaches to the treatment of a viral infection exist.
Because there is strong evidence for a direct relation between viral replication
and activity of the liver disease, one therapeutic possibility may be to achieve
suppression of viral replication and thus amelioriation of disease activity.
For this purpose drugs that interfere with both viral RNA transcription and the
production of viral proteins can be administered in order to suppress replication
of the virus.
At present however such drugs are. not available. Moreover the infection will not
be cured: instead only the effects will mitigated. Such a drug may suppress both
the immune mechanism, by diminishing protein (HBsAg) production, and the
toxic effects, by reducing proliferation of the virus.
Elimination of the potential of an infected cell to produce a virus is another
possibile approach.
To accomplish this aim, drugs can be used that eliminate ali infected hepatocytes
from the liver. As shown in chapter VI, in chronic hepatitis all hepatocytes
appear to be infected by the virus, as demonstrated by the diffuse cell membranebound
HBsAg localization, so that such a therapy would imply elimination of all
hepatocytes.
If this elimination were to occur rapidly, the result would be massive liver cell
necrosis and death of the patient A more realistic way to eliminate the potential of infected cells to produce virus
would be to cure infection of the hepatocyte.
Such a therapy may be achieved by inhibition of viral DNA synthesis. Since viral
DNA formation depends on reverse transcription, drugs such as phosphonoformic
acid that interfere with reverse transcriptasewould prevent the generation
of cccDNA. However preliminary results with this type of drug are not hopeful. A
decline in viral replication activity is followed by rapid restoration of this activity
after withdrawal of the drug.
Finally, another possibility is to cure the chronic infection by creating a situation
in which newly formed hepatocytes are protected against reinfection by the virus.
In this way, the number of infected hepatocytes will slowly decrease, as a result
of regeneration of the liver, and all infected cells will eventually disappear
Morphometrically estimated variation in nuclear size - A useful tool in grading prostatic cancer
At present there are several grading systems for prostatic carcinoma. Most are difficult to reproduce. An objective method of grading seems to be necessary and could make comparisons between various groups of patients easier and grading more reliable. In the present study morphometrically estimated nuclear size and variation in nuclear size are matched with the survival rates of 207 patients who underwent total perineal prostatetomy for cancer. On the basis of morphometrically estimated variation in nuclear size the patients could be divided into two groups with significantly differing survival rates. In this way it was possible to split the group of patients with grade 2 carcinoma (Mostofi's grading system) into two groups of patients with significantly different survival rates. The survival rates in these two groups did not differ significantly from those in the patients with Grade 1 and Grade 3 tumors respectively. The results are discussed in the light of the recent literature on the subject. Morphometry seems to be a valuable tool in grading prostatic cancer
Metastatic potential of human renal cell carcinoma: experimental model using subrenal capsule implantation in athymic nude mice
The aim of this study was to determine whether subrenal capsule (SRC) implantation is a suitable model for the study of the metastatic potential of our human renal cell carcinoma (HRCC) lines and to establish new sublines with enhanced metastatic ability. NMRI athymic nude mice 7-11 weeks old received SRC implantation of our HRCC lines RC43 and RC21. These lines were not metastatic when implanted s.c. Mice were killed after 4 or 8 weeks, or when moribund. With the RC43 cell line the success rate for implantation was 69%, with 89% of these showing metastases. The average volume of the implanted tumour fragments was 0.5 mm3 (range 0.28-0.7), the average volume at the primary site at the time of death was 9087 (9-32000) mm3. Metastases were found in lymph nodes, liver, spleen, peritoneum, psoas muscle, pancreas, diaphragm and skin. The average volume of the metastases was 4139 (0.5-9000) mm3. Growing cell lines were established in vivo and in vitro from one splenic, one peritoneal, one diaphragmatic, and one hepatic metastasis. These sublines have faster in vivo and slower in vitro growth rates than the parental lines. With the RC21 cell line the success rate for implantation was 56% and the metastatic rate 78%. The average volume of the implanted tumour was 0.8 mm3 (0.28-1.2), the average volume at the primary site at the time of death was 2685 mm3 (1.4-6534) and the average volume of metastases was 7.1 mm3 (0.5-37.5). Metastases were found in lymph nodes, lung and skin. No establishment was attempted for RC21 because of the small dimensions of these metastases. SRC implantation is thus considered a useful tool for the study of the metastatic ability of our cell lines RC43 and RC21. The establishment of new sublines with a faster growth rate and an enhanced metastatic ability will be useful for further studies on the metastatic process
Adjuvant chemotherapy for superficial transitional cell bladder carcinoma: long-term results of a European organization for research and treatment of cancer randomized trial comparing doxorubicin, ethoglucid and transurethral resection alone
Ferritin accumulation and uroporphyrin crystal formation in hepatocytes of C57BL/10 mice: A time-course study
To establish the time-sequence relationship between ferritin accumulation and uroporphyrin crystal formation in livers of C57BL/10 mice, a biochemical, morphological and morphometrical study was performed. Uroporphyria was induced by the intraperitoneal administration of hexachlorobenzene plus iron dextran and of iron dextran alone. Uroporphyrin crystal formation started in hepatocytes of mice treated with hexachlorobenzene plus iron dextran at 2 weeks and in mice treated with iron dextran alone at 9 weeks. In the course of time, uroporphyrin crystals gradually increased in size. Uroporphyrin crystals were initially formed in hepatocytes in the periportal areas of the liver, in which also ferric iron staining was first detected. The amount and the distribution of the main storage form of iron in hepatocytes, ferritin, did not differ between the two treatment groups. Ferritin accumulation preceded the formation of uroporphyrin crystals in hepatocytes in both treatment groups. Moreover, uroporphyrin crystals were nearly always found close to ferritin iron. We conclude that uroporphyrin crystals are only formed in hepatocytes in which also iron (ferritin) accumulates. Hexachlorobenzene accelerates the effects of iron in porphyrin metabolism, but does not influence the accumulation of iron into the liver
Transplacental induction of membranous nephropathy in a neonate
We report a case of renal failure in a newborn infant due to membranous glomerulonephritis. The patient was anuric in the first 3 weeks of life, after which renal function recovered. The serum of the mother contained IgG antibodies which reacted with tubular brush borders and glomeruli of adult and fetal human kidneys. Reactivity with renal epithelium from human kidneys was detected. We suggest that a transplacental, passive Heymann nephritis-like mechanism was the pathogenesis of the neonate's symptoms, although the antigen(s) involved was shown not to be gp 330 or any of the renal antigens known to be involved in experimental nephropathies
Viable Tumor Tissue Adherent to Needle Applicators after Local Ablation: A Risk Factor for Local Tumor Progression
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