Ifosfamide in malignant mesothelioma: a phase II study.

Malignant mesothelioma is a rare malignancy with a median survival, ranging from 4 to 18 months in untreated patients. In a phase II study of patients with mesothelioma, the efficacy and toxicity of ifosfamide and mesna was evaluated. Twenty-nine previously untreated patients, with histologically proven and unresectable mesothelioma, entered the study. Three patients were later excluded from the study due to revision of the diagnoses. The patients had to have bidimensionally measurable disease by CT scans and a WHO performance status < or = 3. Eligible patients received ifosfamide 3000 mg/m2 per day for 3 days as a 1-h infusion and mesna 1800 mg/m2 per day for 3 days every third week. Dose modifications were made according to the degree of hematologic, neurologic and renal toxicity. Response to treatment was evaluated in accordance with WHO criteria. The median age of patients was 59 years (range 39-68), 18 patients (69%) had a history of asbestos exposure and the median of treatment cycles was four (range 1-10). No complete responses were observed. One patient obtained a partial response after five cycles with a duration of response of 25 months. Nine patients (35%) had stable disease, while 13 (54%) progressed. The median survival for all patients was 10 months. The toxicity of the treatment was considerable. Thirteen patients (50%) had grade 4 leucopenia, ten patients (38%) had grade 3 or 4 reversible neurotoxicity and ten patients (38%) had grade 3 or 4 nausea and vomiting. Eleven patients (42%) went off the study due to the toxicity of the treatment. In conclusion, ifosfamide did not show any substantial activity of relevance in malignant mesothelioma at the dose level investigated, in spite of considerable toxicity.

Recurrent nodular haemangiomas in Klippel-Trénaunay syndrome.

A one-year-old child had hypertrophy of the left leg and an unusual constellation of a naevus flammeus and superficial enlarged veins of the trunk together with successive appearance and involution since birth of numerous nodular elements located in the naevus and in the surrounding normal skin. Microscopic examination of these elements showed haemangiomas with capillaries, cavernous channels and lymphangiomatous components. The benign nature of transient nodular elements located to the trunk and the lack of associated visceral vascular malformations in the Klippel-Trénaunay syndrome are documented.

Malignant mesenchymoma of the scrotum.

Paratesticular sarcomas are rare, especially the malignant mesenchymoma. To our knowledge only four cases of paratesticular malignant mesenchymoma have been described previously. All were localized to the spermatic cord. We present a case of malignant mesenchymoma in the scrotum free of the spermatic cord.

Light microscopy and morphometry of vinblastine in vivo cytotoxicity in the different developmental stages of rat incisor ameloblast epithelium.

To see whether the in vivo cytotoxicity of the antimicrotubule agent vinblastine (VB) was related to the degree of differentiation in a normal secretory cell population VB cytotoxicity in the various developmental stages of rat incisor ameloblast was studied. Normal values for cell and nucleus volumes, secretory velocity, VB dose-response curves for cell death, and proliferative and secretory activity were estimated quantitatively using simple stereological methods, 18 and 72 hours after VB administration i.v. Dose-response plots for cell death in jejunal crypt cells and the reduction of secretory activity in acinar pancreatic cells were compared with those of proliferating and secretory ameloblasts. Video light microscopy was used on 2 microns Epon sections with controlled orientation and position, permitting calculation of values on a per-cell-basis or per 10(4) microns 2 epithelial basal area. Normal cell and nuclear mean volumes (range: min.-max. value) for late-differentiating ameloblasts were 557 microns 3 (528-601) and 127 microns 3 (122-136), and for secretory ameloblasts 866 microns 3 (830-886) and 144 microns 3 (142-146). Mean volume of enamel matrix secreted per cell was around 169 microns 3 (122-202) per 24 hrs. Number of cells in the late-differentiating zone was 970(928-1003) and in the secretory zone 828 (820-835) per 10(4) microns 2 epithelial basal area. Cell death after VB in the ameloblast stem cells and pancreatic acinar cells was negligible. 72 hrs after VB, the supply of dividing cells to the proliferation zone was at lower doses increased, while at 3 mg/kg it was reduced to 72% of the normal. All proliferating cells appeared to be killed at 2 mg/kg, together with 38% of the differentiating and 34% of the secretory ameloblasts, and at 3 mg/kg, 70% and 66% respectively of the non-dividing ameloblasts were killed. The secretory output (volume of enamel matrix) of the ameloblasts exposed in the differentiating stage and now transformed into secretory cells was 72 hrs after VB 2 mg/kg reduced to 45%, while that of the mature secretory ameloblasts was reduced to 42%. After VB 3 mg/kg, the differentiated ameloblast zone retained 21% of the normal secretory output, whereas there was no output from the mature cells. Maximal accumulation of zymogen granules in pancreatic acinar cells occurred at 1 mg/kg VB. Unlike to secretory ameloblasts, the morphology of pancreatic acinar cells was normalized at 72 hrs after VB.(ABSTRACT TRUNCATED AT 400 WORDS)

Intraperitoneal granulomatous foreign body reaction after accidental perforation of the abdominal wall. Case report.

After an accidental perforation by a wooden stake of the abdominal wall and distal ileum a 28-year-old man developed an aggressive granulomatous foreign body reaction of the greater omentum with high fever and abdominal pain. The patient was cured by omental resection and prednisone treatment.

Increased plasma membrane traffic in daunorubicin resistant P388 leukaemic cells. Effect of daunorubicin and verapamil.

Numerous studies have indicated that the plasma membrane plays an important role in the development of resistance to anthracycline and vinca alkaloid drugs (pleiotropic resistance). We have previously shown that pleiotropically resistant Ehrlich ascites tumour cells, which are of epithelial origin, have a significantly increased plasma membrane traffic (endo/exocytosis) to the endosomal compartment compared to sensitive cells. The present study, using the same ultrastructural morphometric technique, has demonstrated a similar significant difference in plasma membrane traffic between daunorubicin resistant and sensitive P388 cell lines (which are of lymphoid origin). Furthermore, we have shown that this difference between the P388 sublines is accompanied by an approximately 4 fold increase in the plasma membrane area participating in recycling together with an increased endosomal volume, number and membrane area in resistant cells. Plasma membrane traffic in resistant cells was significantly inhibited by the calcium channel blocker verapamil, a well known modulator of anthracycline resistance, but unaffected by daunorubicin itself. The confirmation of this phenotype in an additional pleiotropically resistant cell type with a different histogenesis further supports a hypothesis of endosomal drug trapping and vesicular extrusion as a possible resistance mechanism.

Increase in nonspecific adsorptive endocytosis in anthracycline- and vinca alkaloid-resistant Ehrlich ascites tumor cell lines.

Numerous biochemical and drug transport studies have focused on the role of the plasma membrane or membrane-associated processes in anthracycline and vinca alkaloid resistance. Cationized ferritin, which binds electrostatically to anionic sites on the plasma membrane, was used as a membrane marker in a morphometrical ultrastructural study. The nonspecific adsorptive endocytosis was significantly increased in Ehrlich ascites tumor cell lines resistant to daunorubicin (DNR), doxorubicin, vincristine, and vinblastine compared to that in sensitive cells. Thus cells resistant to DNR internalized 2.04% of their plasma membrane per minute, in contrast to 1.17% in sensitive cells. Because the measured cell surface areas in sensitive and resistant cells were unchanged during the experiments, increased membrane traffic (recycling) from intracytoplasmic compartments to the plasma membrane must have occurred in resistant cells. Possible implications of these findings include a resistance-linked phenotype without significance for resistance per se, an increase in membrane repair, and a connection between increased membrane traffic and increased active drug extrusion in resistant cells.

Progressive involution and physiological death of smooth muscle cells of rat incisal arterioles.

The sequential morphology of vascular smooth muscle cell involution and physiological cell death was studied by electron microscopy on rat incisors. Concurrently with changes in the pulp of the continuously growing incisor, its arterioles pass through a cycle of growth, remodeling, regression and decay. During the cycle, smooth muscle cells of the arterioles were observed to involute by segregation of cytoplasmic components, formation of autophagic and digestive vacuoles and shedding of cell fragments. Phagocytic vacuoles were found in neighbouring muscle cells and in adventitious macrophages. Concomitant with the involution in some cells, physiological death was observed among other smooth muscle cells. This appears as an apoptosis with sequential transformations of polyribosomes into monoribosomes, nuclear and cytoplasmic condensation, and finally fragmentation followed by phagocytosis mainly by adventitious macrophages. Knowledge of the features of physiological involution and cell death of the vascular smooth muscle cells may be of importance not only in studies of functional remodeling and adaption, but also in the interpretation of vascular lesions.

Preparation of midsagittal semithin Epon sections of the entire secretory ameloblast population in the maxillary rat incisor.

To study cytological changes in the migrating cell layer of the ameloblasts in the rat incisor with semithin Epon sections the ideal section plane would consequently be along the midsagittal plane of the incisor. However, the small dimensions and the complex three-dimensional structure of the apical part of the odontogenic organ covered by alveolar bone make it difficult to orientate and position sections in the midsagittal plane. Serial sectioning of the apical half of the maxillary incisor in the horizontal and sagittal planes clarified the relation of the midsagittal plane of the odontogenic organ to the alveolar bone, and the changes of the sectional profile of the odontogenic organ as a function of its position on the transverse axis of the incisor. From this information a method was designed whereby the two axes of the midsagittal plane were marked directly on the block surface before sectioning, and the position of sections in the midsagittal zone of the ameloblasts standardized.