Comparison of normal piglet bladder damage after PDT with oral or intravesical administration of ALA.

5-Aminolaevulinic-acid (ALA) can be used as an alternative drug in photodynamic therapy of the bladder, since the selective formation of protoporphyrin IX (PpIX) in the tumour and the virtual absence of induced skin photosensitivity are theoretically advantageous for clinical use. A preclinical study was performed, using an in vivo normal piglet bladder model, in order to determine the maximum drug and light doses for reversible tissue damage. Various ALA doses were administered either orally or instilled in the bladder and different radiant exposures were applied. Bladder biopsies were taken at regular intervals and tissue damage was investigated histologically. After oral ALA-administration the PpIX concentration was determined in plasma, erythrocytes and various tissues. In the case of oral administration, reversible bladder damage was observed using 60-75 mg/kg ALA combined with a radiant exposure of 100 J/cm(2) (direct radiant exposure plus scattered 632 nm light) 5-7 h later. For an oral ALA dose of up to 150 mg/kg, the maximum PpIX concentration is reached at approximately 5 h following administration and in neither skin nor bladder tissue is PpIX present at 10-11 h after administration. This ALA dose combined with a radiant exposure of 200 J/cm(2) produces irreversible bladder damage (extensive necrosis and ulceration). In the case of intravesical instillation for 4-4.75 h, an ALA dose of 2.5 g in 50 ml phosphate buffered saline and a radiant exposure of 100 J/cm(2) are still too high to obtain reversible tissue damage; at this dose one of the 13 pigs developed a shrunken bladder with a fibrotic, thickened bladder wall. These drug and light combinations reported above should be regarded as upper limits in pigs and can serve as an indication for the toxicity of the treatment in a clinical setting.

Negative sural nerve biopsy in neurolymphomatosis.

Patients with non-Hodgkin's lymphoma occasionally develop widespread invasion of peripheral nerves by tumor cells or neurolymphomatosis (NL). Clinically this usually results in asymmetrical, progressive, and painful polyneuropathy. Diagnosis rests on the identification of tumor cells in peripheral nerves. To avoid false-negative biopsy findings in patients with malignant lymphomatous infiltration of peripheral nerves it has been recommended to biopsy clinically involved nerves. We present two patients with histologically confirmed NL in whom sural the nerve biopsy finding was negative despite clinical and neurophysiological evidence of involvement of the sural nerve a. The clinical features of NL are reviewed. Some patients with neurolyphomatosis have only focal or proximal involvement of nerves, requiring the biopsy of an affected part of these nerves. Magnetic resonance imaging may be useful in identifying affected nerves.

The prognostic significance of expression of the multidrug resistance-associated protein (MRP) in primary breast cancer.

In the present study, we determined the frequency and intensity of MRP protein expression by monoclonal antibody immunohistochemistry in a series of 259 resected invasive primary breast carcinomas, and we evaluated MRP immunoreactivity in relation to patient and tumour characteristics, relapse-free (RFS) and overall survival (OS). The immunostaining was graded on a semiquantitative scale that ranged from (-) to ( ). Overall, 34% of the tumours were positive for anti-MRP antibody: 19% showed weak cytoplasmic staining (+), 14% had clear cytoplasmic staining (++) and only 1% of the tumours had a strong cytoplasmic as well as membranous staining ( ). MRP expression was not related to patient's age, menopausal status, tumour size, differentiation grade, oestrogen and progesterone receptor level or lymph node involvement. In an exploratory univariate analysis of all patients, only primary tumour size and number of lymph nodes involved were significantly associated with shortened RFS (P < 0.001 and P < 0.001 respectively) and OS (P = 0.02 and P < 0.001 respectively). In Cox univariate analysis for RFS in subgroups of patients stratified by menopausal status, tumour size, nodal status, adjuvant systemic therapy and oestrogen and progesterone receptor status, MRP expression was associated with increased risk for failure in patients with small tumours (T1), in node-negative patients and in node-positive patients who received adjuvant systemic chemotherapy with cyclophosphamide, methotrexate and 5-fluorouracil (CMF); the relative hazard rate (RHR) for relapse was increased in the presence of MRP, with RHR values with 95% confidence limits (CL) of 2.8 (1.2-6.9), 2.1 (1.0-4.2) and 2.8 (0.8-9.9) respectively. In analysis for OS, expression of MRP was also associated with increased risk for failure in patients with small tumours (T1) [RHR (95% CL) 2.3 (0.9-6.0)] and in node-positive patients who received adjuvant systemic chemotherapy with CMF [RHR (95% CL) 3.7 (0.8-17.1)] but not in node-negative patients [RHR (95% CL) 1.1 (0.4-2.6)]. In conclusion, our results show that MRP is frequently overexpressed in primary breast cancer and suggest that MRP expression might be of prognostic significance in the subgroups of patients with the more favourable prognosis, i.e. patients with small tumours and node-negative patients, as well as in the setting of adjuvant systemic chemotherapy. In primary breast cancer, MRP might be related to altered cell biological behaviour, including a more aggressive phenotype, and resistance to adjuvant systemic chemotherapy.

A clinicopathological study of 30 melanomas of the vulva.

Thirty cases of malignant melanomas of the vulva were studied for prognostic factors. Ulceration, tumor thickness, and positive inguinal lymph nodes were the most important prognostic factors. Morphometry did not demonstrate any prognostic meaning. Traditionally a radical vulvectomy and bilateral inguinal lymph node dissection were the therapy of choice, but this treatment modality did not show a better survival than less radical treatment. A low-risk and a high-risk group of patients have been identified for recurrence. The low-risk patient has a nonulcerative tumor, less than 3 mm thick, without clinical evidence of inguinal lymph node metastases, and should be treated by local excision with a 2- to 3-cm margin. The high-risk patient has a tumor which is ulcerative and/or more than 3 mm thick and should also be treated by local excision without elective inguinal node dissection. If clinical suspicion of inguinal lymph node metastases exists, an inguinal node dissection is advocated for better local control of the disease.

CSF cytology versus immunocytochemistry in meningeal carcinomatosis.

CSF immunocytochemistry with monoclonal antibodies was compared with conventional cytology to determine its sensitivity in detecting malignant cells in patients with meningeal carcinomatosis. One hundred and eighteen samples were investigated. Cytology was tumour positive in 83 samples and immunocytochemistry in 85. Dissimilar results between the two diagnostic methods were noted in 12 specimens, invariably occurring in samples with a low cell count and obtained from treated patients. Combined use of the two methods led to a 9% increase of sensitivity in detecting malignant cells compared with cytology alone. It is concluded that immunocytochemistry is of minor help in the problem of false-negative cytology in meningeal carcinomatosis.

Determination of transferrin receptors on frozen sections of malignant B-cell lymphomas by immunofluorescence with a monoclonal antibody.

A series of 34 B-cell lymphomas was studied for the presence of transferrin receptors by immunofluorescence on frozen tissue sections with a monoclonal antibody. These lymphomas were classified by light microscopic study and furthermore investigated by immunohistochemical and morphometric methods. There were diffuse centrocytic, diffuse centroblastic, and follicular and diffuse centrocytic/centroblastic lymphomas. Significant differences in log mean nuclear area in these four histologic groups were found, as well as a significant correlation between log nuclear area and transferrin receptors as measured semiquantitatively by fluorescence intensity of the cell membranes. In addition, it was found that there is a strong correlation between the transferrin receptor activity and malignancy grading on histologic and morphometric basis. Therefore, the transferrin receptor determination on frozen sections appears to be a good method of malignancy grading.

Donor pretreatment-mediated and cold storage-dependent proximal tubular necrosis--a unique form of acute renal insufficiency.

After a 5-hour period of donor pretreatment with cyclophosphamide (CY) and methylprednisolone (P) (100 mg/kg each), cold storage of pretreated canine renal allografts may cause early and severe postoperative renal insufficiency. This renal insufficiency is mediated by CY metabolites and depends on the number of hours of cold storage, for severe renal insufficiency is not observed after 6 hours of cold storage but is invariably present after cold storage beyond 18 hours. The renal insufficiency is associated with coagulation necrosis of the proximal tubules, particularly the pars recta. Since the repair of ischemia-medicated proximal tubular lesions requires mitotic activity, results suggest that the proximal tubules of donor pretreated kidneys are subjected to a concentration of CY metabolites sufficient to cause an extent of DNA damage that, in the absence of a sufficient time for nuclear repair, inevitably leads to cell death and renal insufficiency when the tubular cells are driven to mitosis by cold storage-mediated ischemia.

Medullary differentiation of anaplastic thyroid carcinoma.

Fourteen cases of anaplastic carcinoma of the thyroid (ACT) were studied with silver staining and immunohistochemical technics for signs of medullary differentiation. For comparison a series of 11 cases of medullary carcinoma of the thyroid (MCT) was studied. In nine out of 14 cases of ACT both argyrophilia and immunoreactive calcitonin could be detected as evidence of an apparent C-cel origin of these tumors. Most of the patients with these anaplastic medullary carcinomas died within 6 months after the histological diagnosis was made. It is concluded that the histological diagnosis of anaplastic variants of MCT can only be made on the basis of argyrophilic cytoplasmic granules and calcitonin immunoreactivity. In contrast to well differentiated MCT the anaplastic medullary carcinoma is characterized by a poor prognosis.

Giant cell tumour: metaphyseal or epiphyseal origin?

The question whether giant cell tumours (GCT) of tubular bones originate in the metaphysis or epiphysis, was investigated by studying 233 GCT registered in the files of the Netherlands Committee on Bone Tumours. In 6 cases the GCT was found to be located in the metaphysis exclusively, no case with a purely epiphyseal localization was found. The result of this study favours the metaphyseal origin of GCT. An unusual case is discussed.