Malignant nerve sheath tumors of the head and neck: four case studies and review of the literature

Malignant peripheral nerve sheath tumors (MPNST) are very uncommon neoplasms. While the incidence of these lesions is estimated to be 0.001% in a general population, they make up 5-15% of all soft tissue sarcomas in the head and neck region. We present four cases of MPNST in the head and neck. Since certain difficulties were encountered in diagnosis, the importance of clinical evaluation is emphasized. The prognosis for these tumor patients is poor in spite of improvements in diagnostic and therapeutic modalities.

Toxic effects of human pancreatic and snake and bee venom phospholipases A2 on MCF-7 cells in culture

The toxicity of phospholipase A2 (PLA2) has been suggested to be involved in the pathology of a number of severe diseases including septic shock and acute pancreatitis. However, testing the toxicity of these substances is difficult in vivo. In the present study we compared the toxicity of PLA2s from three snake venoms, bee venom and human pancreas on MCF-7 cells grown in culture. Tetrazolium microculture assays were developed to test the cytostatic and cytotoxic effects of PLA2 on MCF-7 cells. These tests are based on the ability of viable cells to reduce a tetrazolium-based compound MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] to a blue formazan product. Leakage of lactate dehydrogenase (LD) from the cells into the culture medium was also measured. There were marked differences in the toxicity of the PLA2s tested. Cobra (Naja mosambique mosambique) venom PLA2 was toxic to the cells at a concentration of 4.5 U/ml. Light microscopic changes were seen in the injured cells after 3 hr treatment. Sixty-seven per cent of cells were dead after 24 hr treatment. Treatment for 4 hr caused irreversible changes in the cells. Leakage of LD was noted from 4 hr onwards. Other snake (Crotalus adamanteus and Laticauda semifasciata) venom PLA2s, even after continuous exposure to 4.5 U/ml caused only slight decreases in values obtained in the MTT test. No morphologic changes suggesting a cytotoxic effect were seen. PLA2 from bee (Apis mellifera) venom had no toxic effect, either. Continuous exposure of cells to human pancreatic PLA2 caused a 15% decrease in the MTT-test.(ABSTRACT TRUNCATED AT 250 WORDS)

Time trends in mortality in forestry and construction workers in Finland 1970-85 and impact of adjustment for socioeconomic variables

STUDY OBJECTIVE

This study aimed firstly to describe the development of cause-specific mortality in forestry workers, farmer/forestry workers, and skilled and semiskilled construction workers between 1970 and 1985 in Finland, and to compare this with mortality in the total working male population. The second aim was to evaluate how well the cause-specific mortality differences between the occupations could be explained by differences in socioeconomic status, marital status, or in the region of residence.

DESIGN AND SETTING

This is a follow up study based on the 1970, 1975, and 1980 census records in Finland linked with all death certificates for 1971-75, 1976-80, and 1981-85 respectively. Log-linear regression analysis was used.

SUBJECTS

All economically active men in Finland aged between 35 and 64 years in 1971-85 were studied. The number of person-years in the period totals about 10 million.

MAIN RESULTS

Semiskilled construction workers had the highest mortality rate almost independent of the cause of death. The mortality of forestry workers was the second highest. Compared with the reference population, however, the differences were small with regard to neoplasms and cardiovascular diseases. With regard to other diseases, only the mortality of semiskilled workers was fairly high. Differences in mortality as a result of accidents were the highest. Both suicide and accidental death rates were high in semi-skilled construction workers and forestry workers. During the study total mortality fell by about 30% but mortality differences between groups did not decline.

CONCLUSIONS

The high mortality of forestry and semiskilled construction workers is partly explained by socioeconomic factors such as marital status and housing conditions. These factors do not, however, explain the high suicide and accident mortality rates of forestry workers or semiskilled construction workers. More research is needed to explain these findings.

Ultrastructure and immunohistochemistry of a fetal-type Leydig cell tumor

A symptomless scrotal mass was removed from a 34-year-old man. The lesion was 7 cm in diameter and it was grossly a hemorrhagic cyst with indurated walls. By light microscopy tumor cell clusters and cords were seen infiltrating the testicle, tunica albuginea, and paratesticular tissue. In the immunohistochemical analysis the tumor cells were immunoreactive with anti-S-100 protein and anticarcinoembryonic antigen, but they did not express cytokeratin or alpha-fetoprotein as tested with paraffin sections. Tumor cell clusters were enveloped by a laminin-positive basement membrane. Electron microscopy revealed abundant smooth endoplasmic reticulum, lipid droplets, and membranous whorls in the cytoplasm. Lamellar whorled bodies were also seen in mitochondria, which contained tubulovesicular cristae. The presence of a well-developed, often multilayered basement membrane was confirmed at ultrastructural level. The activity of 3-beta-hydroxysteroid dehydrogenase suggested that the tumor cells were capable of androgen synthesis. The morphological features are reminiscent of fetal-type Leydig cells and are distinctly different from the Leydig cell tumors described so far.

Androgen regulation of programmed death of normal and malignant prostatic cells

Androgen-dependent normal prostatic glandular cells and androgen-dependent prostatic cancer cells can be induced to undergo cell death after androgen ablation. This death does not require the cells to proliferate and occurs as an energy-dependent process collectively referred to as "programmed cell death" in which the cells actively commit "suicide." Associated with this programmed cell death pathway is the enhanced expression of a series of genes and the fragmentation of the genomic DNA into nucleosomal oligomers. This genomic DNA fragmentation is the irreversible commitment step in the death of the cell and results from activation of Ca2+/Mg(2+)-dependent endonuclease activity within the cell nucleus. This activation is due to sustained elevation of intracellular free Ca2+ (Cai) induced after androgen ablation. Metastatic prostatic cancer within an individual patient is heterogeneous, including both androgen-dependent and -independent cancer cells. Thus, androgen ablation is rarely curative since it only induces the programmed death of the androgen-dependent cancer cells without activating this pathway in the androgen-independent cancer cells within the patient. Androgen-independent prostatic cancer cells do not activate this death process after androgen ablation, since this does not induce a sustained increase in Cai. A new approach to treat androgen-independent prostatic cancer cells has focused on the use of chemotherapeutic agents to induce a sustained increase in Cai. These studies demonstrate that if such a sustained elevation in Cai is maintained, even androgen-independent prostatic cancer cells undergo programmed cell death.

Programmed death of nonproliferating androgen-independent prostatic cancer cells

Androgen ablation induces an energy-dependent process of programmed death in nonproliferating androgen-dependent prostatic cancer cells which involves fragmentation of genomic DNA into nucleosomal oligomers catalyzed by nuclear Ca2+, Mg(2+)-dependent endonuclease enzymes activated following a sustained elevation in intracellular free Ca2+ (Cai). In contrast, androgen-independent prostatic cancer cells are not induced to undergo such programmed cell death by androgen ablation. One explanation for the inability of androgen ablation to induce programmed death of androgen-independent prostatic cancer cells is that such ablation does not result in a sustained elevation in Cai in these cells. This raises the issue of whether androgen-independent prostatic cancer cells can be induced to undergo programmed death if an elevation in the Cai is sufficiently sustained by nonhormonal means. To test this possibility, androgen-independent, highly metastatic Dunning R-3327 AT-3 rat prostatic cancer cells were chronically exposed in vitro to the calcium ionophore ionomycin to sustain an elevation in their Cai. These studies demonstrated that an elevation of Cai as small as only 3-6-fold above baseline can induce the death of these cells if sustained for greater than 12 h. Temporal analysis demonstrated that the death of these cells does not require cell proliferation and involves Ca(2+)-induced fragmentation of genomic DNA into nucleosome-sized pieces as the commitment step in this process. These results demonstrate that even nonproliferating androgen-independent prostatic cancer cells can be induced to undergo programmed cell death if a modest elevation in the Cai is sustained for a sufficient time. These observations identify Cai as a potential target for therapy for androgen-independent prostatic cancer cells.

Effect of transforming growth factor-beta 1 on proliferation and death of rat prostatic cells

The ability of transforming growth factor B1 (TGF beta 1) to inhibit proliferation and activate death of rat ventral prostatic glandular cells was tested both in vivo and in vitro. In vivo administration of 50 ng TGF beta 1/day directly to the regressed ventral prostate of previously castrated male rats had no effect on the proliferative regrowth of the prostatic glandular cells induced by exogeneous androgen replacement. In addition, androgen-stimulated ventral prostatic cell proliferation in vitro in organ culture was not affected by exposure to 0.1-20 ng/ml TGF beta 1. In contrast in vivo administration of 50 ng TGF beta 1/day directly to the ventral prostate of intact noncastrated male rats resulted in the death of about 25% of the prostatic glandular cells within 7 days of treatment. Such TGF beta 1 treatment did not lower serum testosterone, nor did it affect the size or DNA content of the seminal vesicles, demonstrating the local nature of the response. Likewise, in androgen-maintained ventral prostate organ cultures in vitro, there was a dose-response relationship between glandular cell death and TGF beta 1 concentration in the medium. These results demonstrate that TGF beta 1 can induce the death of androgen-dependent prostatic glandular cells even when physiological levels of androgen are present. Previous studies have demonstrated that both the receptor and the mRNA for TGF beta 1 increase rapidly in the ventral prostate after castration. Taken with the present data, these results suggest that TGF beta 1 may be a physiological intermediate in the programmed cell death of rat prostatic glandular cells activated after androgen ablation.

An organ culture system for the study of programmed cell death in the rat ventral prostate

Glandular epithelial cells of the rat ventral prostate undergo programmed cell death in vivo following androgen ablation. Fragmentation of the prostatic DNA is an irreversible commitment step in this programmed cell death process. The amount of prostatic DNA fragmentation thus is a quantitative measure of the number of androgen-dependent prostatic glandular cells undergoing programmed death. An in vitro organ culture system was devised for determining rates of prostatic programmed cell death based upon the daily percentage of prostatic DNA fragmentation. To do this, rats were castrated and 2 weeks later treated in vivo for 3 days with exogenous androgen replacement to maximally stimulate DNA synthesis (i.e. proliferation) of the ventral prostatic glandular cells. In vitro organ cultures were established from these ventral prostates and the DNA of these explants was 125I-labeled by incubation in media containing [125I]iododeoxyuridine [( 125I]IDU). Using this in vivo-in vitro DNA labeling technique, greater than 85% of the [125I]IDU radioactivity was incorporated into DNA of the prostatic explants glandular cells. The decrease in 125I-radioactivity from prostatic explants was determined for over a 10-day period of organ culture. Using regression analysis of these data, the daily rate of programmed cell death of the glandular cells was determined. To test the validity of the method, organ cultures were maintained in media capable of inducing either necrotic (i.e. HgCl2-containing media) or programmed cell death (i.e. media lacking testosterone) and the daily decrease in the percentage of [125I]IDU retained in the tissue determined. In addition, the morphologic appearance of necrotic vs apoptotic cell death (i.e. programmed) was quantitated and compared to the [125I]IDU data. These studies demonstrated that this [125I]IDU labeled rat prostatic organ culture system can be used as an in vitro screen to quantitate the ability of various test agents to activate the programmed cell death pathway in prostatic glandular cells.

The influence of steroidal and nonsteroidal estrogens on the 5 alpha-reduction of testosterone by the ventral prostate of the rat

The 5 alpha-reduction of testosterone to dihydrotestosterone (DHT) correlates with the androgen-mediated growth of the prostate under different experimental and clinical conditions. The aim was to study the regulation of the prostatic growth and enzyme activity by steroidal and nonsteroidal estrogens. Estrogens did not activate the androgen-dependent 5 alpha-reductase activity in cultured prostate of the rat. The direct inhibition of the enzyme activity by estrogens at the concentrations achievable in the male is not probable either. However, early estrogenization of the male rats in utero (on Day 17 of pregnancy) with diethylstilbestrol (DES) resulted in a persistent decrease of the enzyme activity and growth of the prostate indicating a critical estrogen-sensitive period in the regulation of the ultimate enzyme activity. The similar DES-like inhibitory effect on the growth of the prostate was achieved by keeping animals from fertilization throughout the pregnancy until weaning on diet containing soy, rich in environmental estrogens. Zearalenone (Zeranol) and coumestrol, two nonsteroidal estrogens found in human and animal food mimicked estradiol action in culture, but they were not estrogenic or antiestrogenic when administered to normal adults.

Role of calcium in the programmed death of rat prostatic glandular cells

By using a newly developed and validated rat ventral prostatic organ culture system in which prostatic glandular cells can be induced to undergo programmed cell death, the role of an elevation in the intracellular free Ca2+ concentration in this death process was studied. By using this organ culture system, ventral prostatic glandular epithelial cells can be maintained in culture for a period of more than 14 days with a low daily rate of cell death (i.e., approximately 5% die per day) if androgen is included in the media. In contrast, if androgen is not included in the media, the daily rate of prostatic glandular cell death increases approximately 3-fold (i.e., approximately 15% die per day). With this organ culture system it has been demonstrated that the daily rate of programmed death of the glandular epithelial cells can be shifted from 5% to 15% of the cells dying per day when testosterone and 10 microM of the Ca2+ ionophore A23187 are both present in the media. Thus, when the intracellular free Ca2+ is elevated within prostatic cells by means of ionophore treatment, the daily rate of glandular cell death in the presence of testosterone is identical to that induced when testosterone is not present in the media. If the organ cultures are maintained in media lacking testosterone but containing 10 microM of the Ca2+ channel blocker nifedipine to inhibit elevations in the intracellular free Ca2+ derived from the extracellular pools, the rise in the daily rate of cell death from 5 to 15% of the cells dying per day induced by androgen ablation can be inhibited by approximately 70%. These results suggest that an increase within prostatic glandular cells in their intracellular free Ca2+ derived from extracellular Ca2+ pools is a critical early event involved in triggering the subsequent process of programmed cell death (i.e., specifically DNA fragmentation) in these cells following androgen ablation.

Hormonal control of plasminogen activator secretion in organ culture of rat ventral prostate

The usefulness of plasminogen activators (PAs) in the follow-up of the secretory function of the prostate in culture, as well as the hormonal control of these secretory proteins was studied. Organ culture of rat ventral prostate was used as an experimental model. PA secreted into the culture medium during the two weeks' culture period was of the urokinase-type in all culture conditions, as determined by zymography. The highest activities at the end of culture were found in the involuting prostate in cultures without any hormones. As the epithelial component is strongly reduced in the involuted explants, these high activities were suggested to be derived from stroma. Corticosterone (10(-7) mol/l) and insulin (80 U/l) reduced significantly the secretion of PA, and this reduction was attenuated when the favourable effect of these hormones on the maintenance of morphology and tissue weight was taken into account. Testosterone (10(-7) mol/l) increased significantly the secretion of PA in all hormone-treated cultures, which could be due to the increased secretory activity of the epithelium. Interactions between the hormones were significant, i.e. the effects of the hormone combinations were different and could not be calculated from the separate effects of these hormones. Even though the general growth and function of the prostate is strictly androgen-controlled, these results suggest that the control of PA secretion is multihormonal.

Multihormonal control of synthesis and secretion of prostatein in cultured rat ventral prostate

The synthesis and accumulation of prostatein, a major secretory protein of the rat ventral prostate, was examined in organ culture conditions. For the quantitation of this protein in the medium, a sensitive enzyme immunoassay was developed. The rat ventral prostate could be maintained in organ culture in defined medium for at least 2 weeks. Morphologically the changes in explants cultured without hormones resembled those of castration. These involutive changes could be postponed by testosterone and totally prevented by a combination of testosterone, corticosterone, and insulin in the culture medium. Newly synthesized prostatein, studied by fluorography of [35S] methionine-labeled proteins, accumulated only in the presence of testosterone. Its synthesis also took place in cultured prostate derived from castrated rats. Neither corticosterone nor insulin alone could sustain prostatein synthesis. Insulin increased the testosterone-dependent prostatein synthesis in the beginning of culture, but later, inhibition, rather than stimulation, could be noted. Corticosterone increased the testosterone-dependent synthesis of prostatein throughout the culture. The results show that organ culture of adult rat ventral prostate provides an in vitro model for studies of differentiated prostatic function.

Maintenance of adult rat ventral prostate in organ culture

Androgens postpone the involution of prostatic tissue cultured in a chemically defined medium. However, after 1 week quantitative changes are accentuated and qualitative signs of involution appear. Other factors in addition to androgens are obviously needed for the adequate maintenance of the tissue. This study was aimed at the improvement of the culture conditions by adding insulin, corticosterone, epidermal growth factor, prolactin, and transferrin alone or in different combinations with testosterone and each other. A morphometric model developed for prostate culture was used, and maintenance and proliferation of the tissue were further followed by weighing the cultured explants and by measuring the incorporation of (3H) thymidine into DNA. The androgen dependency was seen in all the studied morphometric parameters at least for 2 weeks-i.e., in volume density and height of epithelium (VVEP and h), reflecting the epithelial maintenance, in volume density and width of interacinar tissue (VVIT and lambda AP), reflecting stromal tissue, and in volume density and diameter of lumen (VVLU and DLU), reflecting the secretory function. Testosterone (10(-7) M) also prevented partially the quantitative involution of the tissue within 2 weeks. Insulin, acting independently of androgen, was a potent mitogen, which, according to morphometric results, exerted its effect mainly on prostatic epithelium. Stratification of epithelium was frequently seen. Corticosterone had no effect on epithelian proliferation, but it probably stimulated secretion and inhibited the growth of stroma. By combining these three hormones it was possible to maintain not only the structure but also the amounts of tissue components practically unaltered at least for 2 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunoscintigraphic evaluation of lymph node involvement in prostatic carcinoma

Five patients who were candidates for radical prostatectomy were investigated. One milligram of diethylene triamine pentaacetic acid derivatives of purified F(ab')2 fragments of monoclonal antibodies against prostatic acid phosphatase, labeled with 99mTc, were bilaterally injected into the periprostatic space. The amount of radioactivity injected varied between 3 and 7 mCi. Imaging took place dynamically for the first hour following injection, then at 6 and 24 hr. In one patient, lymph node metastases were detected in the left paraaortic, iliac, and obturator lymph nodes by this technique. The lesions incorporating radioactivity were confirmed to be metastases of prostatic cancer following staging pelvic lymphadenectomy. Immunolabeling electron microscopy studies revealed internalized antibody in prostatic cancer cells. In the four other patients, radioimaging did not show any lymph node metastases, and this negative finding was confirmed at surgery. These early data indicate the possibility of preoperative staging of prostatic cancer using radiolabeled derivatives of monoclonal antibodies raised against prostatic acid phosphatase and injected into the periprostatic area.

Distribution of glycoconjugates in normal rat ventral prostate and their use as markers of androgen-controlled secretory function in culture

The distribution of glycoconjugates in uncultured and cultured rat ventral prostate was studied by using eight fluorescent lectins. The prostate pieces were cultured in defined medium with or without testosterone for 1-14 days. Each lectin revealed a characteristic binding pattern. Con A, LCA, WGA, and RCA I stained both epithelial and interstitial components. SBA and PNA were specific for the epithelium: SBA stained the region of the Golgi complex; PNA showed the brightest fluorescence in the apical part of the cells representing the region of secretory granules. In culture without testosterone the epithelial cells gradually lost their fluorescence, whereas the stromal fluorescence increased. The basement membrane was disorganized. With testosterone the integrity of the epithelium and stroma was maintained, and the staining pattern of the lectins was in the main similar as in vivo. However, at 14 days a change in the staining pattern of apical cytoplasm with PNA was noted, indicating that in long-term cultures, in addition to testosterone, other hormones and growth factors are necessary to complete especially the last stages of the secretory process in the epithelial cells.

A morphometric analysis of rat ventral prostate in organ culture

A stereologic, morphometric method was used for determining the quantitative and qualitative changes in the rat ventral prostate during organ culture. The volume density of epithelium (VVEP), lumina (VVLU), and interstitium (VVIT) as well as the proportion of epithelium of the tissue, VVEP/(VVEP + VVIT), the length density of tubular structures (LV), mean diameter of the lumina (DLU), height of the epithelium (h), and mean width of the interacinar tissue (lambda AP) were evaluated. In the perfusion-fixed prostate these parameters gave the closest approximation for the in vivo situation: VVEP was 0.19 mm3/mm3; h 19.5 micron; VVEP/(VVEP + VVIT) 0.63 mm3/mm3; VVLU 0.70 mm3/mm3; DLU 230 micron; VVIT 0.11 mm3/mm3; lambda AP 84.1 micron; and LV 17.5 mm/mm3. Dissection of the prostate for culture caused leakage of prostatic secretions and a consequent diminution of VVLU (0.41 mm3/mm3) and DLU (151 micron), as well as folding of the epithelium and distortion of the interacinar tissue (VVIT 0.25 mm3/mm3). During 10 days culture in a defined medium, the prostate underwent involutive changes including loss of total weight, a decrease of VVEP, and an increase of VVIT. During the first day a stimulatory effect on the epithelium occurred, which might have been caused by a loss of androgenic control or by substances in leaking secretions. Testosterone postponed many of these changes and maintained the secretory function better. Thus, on day 4 the morphology of the prostate resembled better the situation in vivo than at the beginning of involutionary culture. However, later during culture changes, similar to those found without testosterone but weaker, were noted. Statistical analysis of data showed that it is more advisable to use many pieces from one prostate lobe rather than to use many animals. Analysis of one slice is also sufficient to give relevant data on that piece.

Glucose content as a parameter of semen quality

There are minute and varying amounts of glucose in seminal plasma. Findings on vasectomized men suggest that it is derived from accessory sex glands. The glucose content was shown to correlate negatively to the number of spermatozoa and the time period elapsed from ejaculation, indicating that seminal glucose was utilized by spermatozoa even in the presence of a 50-fold concentration of fructose. Large interindividual variations in the glucose utilization as reflected in the 14CO2 production from 14C-glucose by spermatozoa could not be explained by the parameters examined in routine semen analysis. Fructose and glucose maintained equally well the ATP content and motility of spermatozoa at the concentrations found normally in semen. Fructose may thus supplement and substitute for glucose as an energy source, and the addition of glucose into the semen or the measurement of its content would not give any advantage for the analysis of semen samples.

Flunitrazepam compared with althesin as an induction agent in balanced anaesthesia

The effects of flunitrazepam and Althesin as anaesthetic induction agents were studied in a double-blind trial in 97 patients undergoing abdominal or gynaecological surgery. There was no difference between the two preparations in respect of the quality of induction. A marked difference in the quality of maintenance of anaesthesia were seen, in favour of flunitrazepam. Recovery was more rapid from Althesin anaesthesia. A low incidence of nausea was observed in both groups.