Extragonadal germ cell tumors. A 14-year Toronto experience

BACKGROUND

Extragonadal germ cell tumors (EGCT) represent only 2-5% of adult germ cell malignancies. Because they are rare and biologically distinct from testis cancer, their natural history and optimal management continue to be defined. The clinical characteristics, treatment, and outcome of 40 patients are presented here.

METHODS

Patients were identified through the medical records of four University of Toronto teaching hospitals. All patients were treated in specialized oncology units between 1978 and 1993.

RESULTS

Thirty-seven males and three females age 16-54 years (median, 24 years) with primary mediastinal (n = 24), retroperitoneal (n = 7), CNS (n = 7), and widespread (n = 2) EGCT were identified. Eight of nine patients (88%) with mediastinal seminoma are alive with no evidence of disease (NED) at 4-132 months (median, 45 months). After combined modality therapy, only 8 of 15 patients (53%) with mediastinal nonseminomas achieved complete remission (CR); 1 experienced relapse and died, resulting in 7 of 15 patients (47%) with NED at 45-86 months (median, 70 months). All three patients with retroperitoneal seminomas achieved CR and all have NED at 77, 103, and 120 months, respectively. Two of four patients with retroperitoneal nonseminomas have died, and the other two are alive at 36 and 54 months. Seven patients with CNS germinomas (seminoma) achieved CR after craniospinal radiation therapy, but one subsequently died after local relapse. The overall survival rate was 87% (median, 74 months). One patient with widespread choriocarcinoma died and the other achieved CR.

CONCLUSIONS

Regardless of site of presentation, extragonadal seminomas have a greater than 80% 5-year disease-free survival rate. Mediastinal nonseminomas are biologically distinct, with a poorer prognosis. Treated with cisplatin-based chemotherapy followed by aggressive resection, approximately 50% of patients survive. CNS seminomas have a good prognosis. Nonseminomas of the CNS are extremely rare and were not represented in the current series. These findings concur with other reported series.

Dietary glutathione intake and the risk of oral and pharyngeal cancer

Glutathione, a tripeptide found in a variety of foods, may function as an anticarcinogen by acting as an antioxidant and by binding with cellular mutagens. The association between dietary glutathione intake and risk of oral and pharyngeal cancer was investigated using data from 1,830 white participants (855 cases and 975 controls) in a population-based case-control study conducted in New Jersey; metropolitan Atlanta, Georgia; Los Angeles County, California; and Santa Clara and San Mateo counties, south of San Francisco-Oakland, California, during 1984-1985. The estimated relative risk of cancer among people with the highest quartile of glutathione intake from all sources was 0.5 (95% confidence interval 0.3-0.7). When analyzed by dietary source, however, glutathione intakes derived from all vegetables and from meat were not related to risk of cancer. Only glutathione derived from fruit and from vegetables commonly consumed raw was associated with reduced oral cancer risk. Relative to the lowest level of combined intake of fruit and of fruit-derived glutathione, risk of cancer decreased slightly with increasing intake of fruit glutathione. This analysis was limited, however, by the small numbers of subjects with extreme combinations of intakes. Further studies are needed to distinguish the potential effect of glutathione from that of fruit and raw vegetables per se or from the influence of other constituents in these foods.

Abnormal metabolism of S-adenosyl-L-methionine in hypoxic rat liver. Similarities to its abnormal metabolism in alcoholic cirrhosis

S-Adenosylmethionine (AdoMet) is an important biologic methylating agent for nucleic acids, phospholipids, biologic amines, and proteins. Previous studies indicated that hepatic AdoMet synthetase and hepatic levels of AdoMet are subnormal in patients with alcoholic cirrhosis. This abnormality limits the patients' capacity to convert phosphatidylethanolamine to phosphatidylcholine by way of phosphatidylethanolamine-N-methyltransferase (PEMT). Because alcoholic consumption appears to be associated with hepatic hypoxia, we previously measured AdoMet concentration in liver cells under acute hypoxia and found the level to be decreased substantially. In the present study, we determined whether a similar metabolic abnormality was also observed in rats maintained under physiologic hypoxia for 9 days and administered standard rat chow. The study showed that AdoMet levels in hypoxic rat (ave +/- SD) were significantly lower than those in the control (36.8 +/- 11.6 vs. 60.4 +/- 2.3 nmol/g liver; P < 0.05). Also significantly lower in the hypoxic group were the activities of AdoMet synthetase (0.60. +/- 0.07 vs. 0.97 +/- 0.20 U; P < 0.05) and PEMT (26.2 +/- 4.2 vs. 35.6 +/- 5.8 U; P < 0.02). The mRNA levels of AdoMet synthetase also declined in hypoxia indicating that hypoxia may modulate the gene expression of hepatic AdoMet synthetase. Thus, in vivo hypoxia may have an important effect on 1-carbon metabolism.

Dietary glutathione intake in humans and the relationship between intake and plasma total glutathione level

Glutathione may function as an anticarcinogen by acting as an antioxidant or by binding with cellular mutagens. Orally administered glutathione increases plasma glutathione levels, and plasma glutathione is also synthesized in the liver. To investigate the associations between glutathione intake and plasma glutathione level, we compared dietary intake estimates from food frequency questionnaire data and measured concentrations of plasma total glutathione and other serum antioxidants in 69 white men and women. Daily glutathione intake ranged from 13.0 to 109.9 mg (mean 34.8 mg). Fruits and vegetables were found to contribute over 50% of usual dietary glutathione intake, whereas meats contributed less than 25%. Small negative correlations were observed between dietary and plasma glutathione and, although they were usually not statistically significant, they were generally consistent by different time periods of dietary intake assessment. Adjustment for sex, age, caloric intake, and dietary intake of the sulfur-containing amino acids methionine and cystine did not alter the observed associations. The correlations appeared to be modified, however, by serum vitamin C concentration, with little or no association between dietary and plasma glutathione among those with lower levels of serum vitamin C and stronger negative correlations among those with higher serum vitamin C levels. These findings indicate that factors regulating plasma glutathione concentration are complex and not simply related to dietary glutathione intake or supply of precursor amino acids.

Protection of retinal pigment epithelium from oxidative injury by glutathione and precursors

PURPOSE

This study was performed to examine the effect of exogenous glutathione (GSH) or its precursor amino acids on oxidative injury in cultured human retinal pigment epithelium (RPE).

METHODS

Cultured human RPE cells were suspended in Krebs-Henseleit medium, and 150 microM t-butylhydroperoxide was added. Cell viability was assessed by 0.2% trypan blue exclusion 30, 60, and 120 minutes after the addition of GSH or its amino acid precursors.

RESULTS

Added GSH provided protection at concentrations of 0.01 mM and higher. The amino acid precursors for GSH, glutamate, cysteine, and glycine also protected against injury, but this required at least 0.1 mM of each amino acid. Inhibition of intracellular GSH synthesis by inclusion of 1 mM buthionine sulfoximine eliminated the protection by added amino acids but did not alter the protection by added GSH.

CONCLUSIONS

These results indicate that protection by the amino acid precursors is mediated through synthesis of GSH, and they also show that exogenous GSH can provide protection against oxidative injury.

Revascularization for acute regional infarct: superior protection with warm blood cardioplegia

Continuous retrograde warm blood cardioplegia was compared with two widely used hypothermic myocardial protection techniques in a canine model of acute regional myocardial ischemia with subsequent revascularization. Animals (n = 30) underwent 45 minutes of left anterior descending coronary artery occlusion then cardioplegic arrest (60 minutes), followed by separation from cardiopulmonary bypass and data collection. The cold oxygenated crystalloid cardioplegia group (CC; n = 8) and the cold blood cardioplegia group (CC; n = 10) had cardiopulmonary bypass at 28 degrees C, antegrade arrest, and intermittent retrograde delivery. The warm blood cardioplegia group (WB; n = 12) had normothermic cardiopulmonary bypass, antegrade arrest, and continuous retrograde delivery. Overall ventricular function (preload recruitable stroke work relationship; ergs x 10(3)/mL) was significantly (p < 0.001) better for WB (WB, 80 +/- 11; CB, 67 +/- 13; CC, 57 +/- 12). Systolic function (maximum elastance relationship; mm Hg/mL) was also significantly (p < 0.001) better for WB (WB, 11.6 +/- 3.6; CB, 8.6 +/- 2.7; CC, 6.2 +/- 1.3). Diastolic function (stress-strain relationship; dynes x 10(3)/cm2) revealed significantly (p < 0.001) decreased compliance for CC (WB, 20 +/- 6; CB, 19 +/- 7; CC, 27 +/- 11). Left anterior descending coronary artery regional adenosine triphosphate/adenosine diphosphate ratios were significantly (p = 0.02) worse for CC (WB, 10.2 +/- 2.3; CB, 9.4 +/- 2.6; CC, 5.6 +/- 1.5). Myocardial edema significantly (p = 0.03) increased over time only in the CC animals (WB, 0.4% +/- 2.3%; CB, -0.3% +/- 3.6%; CC, 5.5% +/- 2.3%). In this model of acute regional myocardial ischemia and revascularization, continuous retrograde warm aerobic blood cardioplegia provided superior myocardial protection compared with cold oxygenated crystalloid cardioplegia with intermediate results for cold blood cardioplegia.

Plasma total glutathione in humans and its association with demographic and health-related factors

The tripeptide glutathione is proposed to be protective against a number of chronic diseases including cardiovascular disease and cancer. However, there have been few studies of plasma glutathione levels in humans and in those studies the numbers of participants have been very small. In an exploratory analysis the determinants of plasma total glutathione (GSHt) were investigated in a group of 100 volunteers aged 18-61 years in Atlanta, Georgia, USA during June and July 1989. Data on demographic and health-related factors were collected by interview and plasma GSHt was measured using a recently modified laboratory method. The mean concentration of plasma GSHt for all 100 participants was 761 micrograms/l, with a standard deviation of 451 micrograms/l, a range of 86-2889 micrograms/l and a median of 649 micrograms/l. Men had significantly higher levels of plasma GSHt than women (924 v. 692 micrograms/l; P = 0.006). Seventh-day Adventists participating in the present study had higher plasma GSHt levels than other subgroups defined by race and/or religion. Among Seventh-day Adventists consumption of a vegetarian diet was associated with increased plasma GSHt concentration (P = 0.002). Plasma GSHt levels also appeared to vary by race, but relationships with race could not be clearly disassociated from relationships with religion. Among white participants plasma GSHt concentration decreased with age in women but increased with age in men (P = 0.05). Few other factors were associated with plasma GSHt concentration, although use of oral contraceptives (P = 0.10) was somewhat associated with decreased plasma GSHt levels. These findings suggest that plasma GSHt levels may vary with several demographic and health-related attributes and support the need for further research on this potentially important disease-preventive compound.

Polarity of taurine transport in cultured renal epithelial cell lines: LLC-PK1 and MDCK

We characterized taurine transport in two continuous renal epithelial cell lines: LLC-PK1, derived from the proximal tubule of the pig, and the Madin-Darby canine kidney (MDCK), which was originated from the distal tubule of the dog. In the LLC-PK1 cell line, taurine transport is greatest at the apical surface of the cell, whereas in the MDCK cell line taurine transport is greatest at the basolateral surface. Both apical and basolateral surfaces of LLC-PK1 and MDCK cells exhibit an adaptive response to the extracellular taurine concentration (medium taurine concentration). Only the basolateral surface of the MDCK cell responded to hyperosmolality with increased taurine accumulation. This indicates differential control of the beta-amino acid transport system by substrate and external tonicity. The function of the beta-amino acid transport system may be different depending on the cell. In the LLC-PK1 cell, there is net transepithelial movement of taurine and changes in transporter activity in response to supply of substrate. In contrast, taurine accumulation by the MDCK cell appears to be a mechanism for adaptation to osmotic stress.

Can children withhold consent to treatment?

A dilemma exists when a doctor is faced with a child or young person who refuses medically indicated treatment. The Gillick case has been interpreted by many to mean that a child of sufficient age and intelligence could validly consent or refuse consent to treatment. Recent decisions of the Court of Appeal on a child's refusal of medical treatment have clouded the issue and undermined the spirit of the Gillick decision and the Children Act 1989. It is now the case that a child patient whose competence is in doubt will be found rational if he or she accepts the proposal to treat but may be found incompetent if he or she disagrees. Practitioners are alerted to the anomalies now exhibited by the law on the issue of children's consent and refusal. The impact of the decisions from the perspectives of medicine, ethics, and the law are examined. Practitioners should review each case of child care carefully and in cases of doubt seek legal advice.

Selective depletion of mitochondrial glutathione concentrations by (R,S)-3-hydroxy-4-pentenoate potentiates oxidative cell death

The hepatocellular glutathione content is partitioned into a cytosolic pool, which accounts for about 85% of the cellular glutathione content, and a mitochondrial pool, which accounts for about 15% of the cellular glutathione content. Previous studies indicated that the mitochondrial glutathione pool may play a critical role in cytoprotection against xenobiotic-induced cell damage. Tests of the role of mitochondrial glutathione in cytoprotection have been hampered by the lack of agents that selectively deplete the mitochondrial glutathione pool. To test the hypothesis that mitochondrial glutathione plays a critical role in protecting against cytotoxic agents, we developed a method to deplete selectively mitochondrial glutathione concentrations. (R,S)-3-Hydroxy-4-pentenoate, an analog of (R)-3-hydroxybutanoate, caused a rapid and selective depletion of mitochondrial glutathione concentrations. Incubation of (R,S)-3-hydroxy-4-pentenoate with rat liver mitochondria or with 3-hydroxybutyrate dehydrogenase in the presence of glutathione afforded a glutathione conjugate whose chromatographic properties were identical with synthetic S-(3-oxo-4-carboxybutyl)glutathione, indicating that (R,S)-3-hydroxy-4-pentenoate was oxidized to the Michael acceptor 3-oxo-4-pentenoate, which reacts with glutathione. Exposure of rat hepatocytes to (R,S)-3-hydroxy-4-pentenoate, which was not cytotoxic and did not induce mitochondrial dysfunction, potentiated the cytotoxicity of tert-butyl hydroperoxide. These results establish the critical role of mitochondrial glutathione in cytoprotection and demonstrate and (R,S)-3-hydroxy-4-pentenoate may find utility in exploring mitochondrial glutathione homeostasis.

Arteriovenous fistula after biopsy of renal transplant kidney: diagnosis and treatment

An 11-year-old renal transplant recipient was noted to have a bruit over her transplant graft 26 months post transplant and 17 months following percutaneous renal biopsy during an episode of rejection. Diagnosis of an arteriovenous (AV) fistula was made by ultrasound examination with Doppler flow and was confirmed with arteriography. The AV fistula was occluded by transcatheter embolotherapy with placement of a steel coil into the fistula from the renal vein approach. This procedure allowed nonsurgical closure of the AV shunt without significant change in renal function.

Pupillometer for clinical applications using dual 256-element linear CCD arrays

A new pupillometer for measuring the size of the pupil of the human eye is described. It uses two inexpensive 256-element charge coupled device (CCD) arrays in an orthogonal configuration. The system is controlled and data are analysed by means of a Z80A microcomputer. Software allows the position and diameter of the pupil to be displayed on a monochrome video monitor. Infra-red diodes irradiate the eye so that measurements can be made in darkness. The accuracy is better than +/- 0.1 mm, over the range 3.2-9.5 mm. Dynamic measurements of the pupil light reflex response can be made with sampling periods as short as 20 ms.

Protective effect of the dimer of 16,16-diMePGB1 against KCN-induced mitochondrial failure in hepatocytes

The dimer and trimer of 16,16-dimethyl-15-dehydroprostaglandin B1 (16,16-diMePGB1) previously have been shown to have protective effects on mitochondrial function. To examine the potential mechanisms involved in protection against mitochondrial failure, we have studied the effects of the dimer of 16,16-diMe-PGB1 (dicalciphor) on mitochondrial function in hepatocytes exposed to KCN. Addition of micromolar concentrations of dicalciphor provided substantial protection against KCN-induced toxicity in a concentration- and time-dependent manner. Dicalciphor, however, had no effect on total or mitochondrial ATP losses in KCN-treated cells. The dimer prevented the marked loss of mitochondrial membrane potential (delta psi) and delta pH that occurs as a result of KCN treatment and prevented KCN-induced loading of phosphate in mitochondria. Furthermore, the dimer of 16,16-diMePGB1 also prevented KCN-induced mitochondrial and cellular swelling. These results demonstrate that dicalciphor protects against KCN-induced damage and that this protection is associated with regulation of specific mitochondrial ion transport functions.

Effect of chronic hypoxia on detoxication enzymes in rat liver

Studies were performed to determine the effects of chronic hypoxia on enzymes that catalyze various detoxication reactions. Rats were exposed to room air or 10.5% O2 for 10 days, and microsomes and postmicrosomal supernatants were isolated from liver. Detoxication enzyme activities were measured by radiochemical and spectrophotometric assays, and immunoreactive protein amounts were measured by Western blot analysis. Total cytochrome P450, as measured by the CO-difference spectrum, and activities of superoxide dismutase (EC 1.15.1.1), epoxide hydrolase (EC 4.2.1.63), catalase (EC 1.11.1.6), glutathione disulfide reductase (EC 1.6.4.2), and glutathione (GSH) S-transferase (EC 2.5.1.18) were not affected by this extent of hypoxia. In contrast, 10 days of hypoxia decreased activities or immunoreactivities (% of aerobic) of GSH peroxidase (EC 1.11.1.9) (54%), cytochrome P450EtOH2 (42%), CYP3A1 (53%), sulfotransferase (EC 2.8.2.1) (77%) and UDP-glucuronosyltransferase (EC 2.4.1.17) (65%). Activity of glucose-6-phosphate dehydrogenase (EC 1.1.1.49), an important enzyme in NADPH production was also decreased to 56% of the aerobic value, but Western blot analysis showed that the amount of protein reactive with antibodies to glucose-6-phosphate dehydrogenase was not affected by hypoxia. Thus, hypoxia may decrease activity of enzymes by regulatory mechanisms even though the amount of immuno-detectable enzyme is unchanged. Liver cells isolated from rats exposed to hypoxia also gave lower GSH synthetic rates than cells from normoxic rats. This result, together with the effect of hypoxia on glucose-6-phosphate dehydrogenase, indicates that the GSH supply for GSH-dependent detoxication reactions may be limited due to chronic hypoxia. To test directly whether chronic hypoxia increased sensitivity to a compound normally detoxified by a GSH-dependent reaction, sensitivity to tert-butyl hydroperoxide (t-BuOOH) of hepatocytes from rats exposed to in vivo hypoxia was compared to that from normoxic rats. The results showed that the cells from the hypoxic rats were much more sensitive to injury. Taken together, these results suggest that decreases in amounts and/or activities of detoxication enzymes during chronic hypoxia may result in increased susceptibility of cells to chemical injury.

Glutathione protection in alveolar type II cells from fetal and neonatal rabbits

Previous studies have demonstrated a correlation between intracellular glutathione (GSH) pools and sensitivity to oxidative injury. In the present study, we demonstrated that de novo GSH synthesis or GSH uptake could increase intracellular GSH by 7- and 19-fold, respectively, in type II cells from neonatal rabbits. This suggested that the rate of GSH uptake was against a concentration gradient and greater than the synthetic rate. This increased intracellular GSH was associated with protection from oxidant injury by paraquat or 80% O2. A relationship between GSH uptake and protection was further supported by blockage of both processes by gamma-L-glutamyl-L-glutamate, a GSH analogue. With a greater oxidative burden, both de novo synthesis and GSH uptake were required to maintain protection. Although the transport rate was only 6% of that for neonatal cells, cells from fetal animals transported GSH and were protected from oxidative injury. From these results we conclude there was a causal relationship between GSH transport and protection from oxidative injury in type II cells from neonatal and fetal animals.

Development of tubular function

This article has reviewed the maturation of major renal tubular transport systems. The tubular reabsorption of certain amino acids and the secretion of organic acids, hydrogen ions, and potassium increases as a function of postnatal age, being relatively immature at birth, especially in the preterm infant. In contrast, the ability for phosphate reabsorption is enhanced during the immature state as the developing animal attempts to adapt to its environment. In the case of glucose, the transport system is relatively mature in the term infant and less so in the infant of less than 34 weeks' gestation. One should consider these developmental changes in the renal tubular transport of amino acids, potassium, phosphate, and organic acids in the nutritional assessment and pharmacologic treatment of preterm as well as term infants.

Protective effect of dicalciphor during mitochondrial failure

Mammalian cells differ considerably in the duration of anoxia which they can tolerate despite the fact that dramatic bioenergetic changes occur rapidly. Previous studies indicate that the ability to tolerate anoxia is at least partly due to an endogenous signal transduction system that senses O2 deficiency and signal altered ion transport functions in the mitochondria. The responses included inhibition of ATP synthase, ADP/ATP exchange, inorganic phosphate uptake, mitochondrial swelling, and loss of the mitochondrial proton-motive force. An important distinction between KCN toxicity and anoxia is that KCN does not elicit these protective mechanisms. Thus, the ability of a compound to elicit these mechanisms in KCN-treated cells provides an assay for potential agonists of the endogenous protective mechanisms.

Characteristics of taurine transport in cultured renal epithelial cell lines: asymmetric polarity of proximal and distal cell lines

Taurine transport was determined in two continuous, renal epithelial cell lines: LLC-PK1 derived from the proximal tubule of the pig, and the Madin-Darby canine kidney cell (MDCK) from the distal tubule of the dog. In LLC-PK1, taurine transport is maximal at the apical surface, whereas in MDCK cells, transport is greatest at the basolateral surface. Transport is highly dependent on both sodium and chloride in the external medium, and is specific for beta-amino acids. The apical and basolateral surfaces of both cell lines show an adaptive response to extracellular taurine concentration, but only the basolateral surface of the MDCK cell responds to hyperosomolality by increased taurine accumulation. Thus, differential control of the beta-amino acid transport system by substrate and external tonicity exists. The role of the beta-amino acid transport system may differ according to the origin of the cell: in the proximal renal tubular cell, net transepithelial reabsorption of filtered taurine increases the body pool. By contrast, taurine accumulation by distal tubular cells may form a mechanism of cell volume regulation in response to osmotic stress.

Testifying in criminal court: emotional effects on child sexual assault victims

Child victims must cope not only with the emotional consequences of criminal acts but also with the potentially traumatizing effects of legal involvement. Dramatic increases in the reporting of child sexual abuse are bringing greater numbers of children into contact with the criminal justice system, raising fears that child victims of sex crimes will be further harmed by the courts. In the present study, the effects of criminal court testimony on child sexual assault victims were examined in a sample of 218 children. From this sample, the behavioral disturbance of a group of "testifiers" was compared to that of a matched control group of "nontestifiers" at three points following testimony: 3 months, 7 months, and after prosecution ended. At 7 months, testifiers evinced greater behavioral disturbance than nontestifiers, especially if the testifiers took the stand multiple times, were deprived of maternal support, and lacked corroboration of their claims. Once prosecution ended, adverse effects of testifying diminished. In courthouse interviews before and after testifying, the main fear expressed by children concerned having to face the defendant. Children who appeared more frightened of the defendant while testifying were less able to answer the prosecutors' questions; and later, after the cases were closed, they were more likely to say that testifying had affected them adversely. The two most pervasive predictors of children's experiences in the courtroom, however, were age and severity of abuse. Despite relevant laws, few innovative techniques were used to help the children testify. The results are discussed in relation to children's ability to cope with stressful situations, the interaction of the legal system with the child/family system, and debates about the need to protect child victims who testify in criminal court.

Glutathione in foods listed in the National Cancer Institute's Health Habits and History Food Frequency Questionnaire

Glutathione (GSH) is an antioxidant and anticarcinogen that is present in plant and animal tissues that form the bulk of the human diet. Recent studies show that GSH is absorbed intact in rat small intestine and that oral GSH increases plasma GSH concentration in humans. To provide a database for epidemiological studies of dietary intake of GSH and risk of diseases in humans, we have measured the content of GSH in the foods listed in the National Cancer Institute's Health Habits and History Questionnaire. Foods were purchased in the Atlanta area and prepared as most commonly consumed in the United States. GSH analyses were performed using a high-performance liquid chromatography technique with a method of additions to correct for losses during sample preparation. A separate set of samples was run after treatment with dithiothreitol to measure the total of GSH and its disulfide forms (GSH). The results show that dairy products, cereals, and breads are generally low in GSH; fruits and vegetables have moderate to high amounts of GSH; and freshly prepared meats are relatively high in GSH. Frozen foods generally had GSH contents similar to fresh foods, whereas other forms of processing and preservation generally resulted in extensive loss of GSH. Thus this database will allow researchers to examine the relationship between dietary GSH and risk of cancers and other diseases.