Synthesis, characterization, and platelet adhesion studies of novel aliphatic polyurethaneurea anionomers based on polydimethylsiloxane-polytetramethylene oxide soft segments

Two novel aliphatic polyurethaneurea anionomers were synthesized based on polydimethylsiloxane (PDMS)-polytetramethylene oxide (PTMO) soft segments. The hard segments consisted of either 4,4'-methylene dicyclohexyl diisocyanate (H12MDI), sulfonic acid-containing diol and 1,4-butandiol (BD) or H12MDI, carboxylic acid-containing diol and BD. The nonionic counterpart chain extended with BD was prepared. In addition, the base nonionic polyurethaneurea containing a pure PDMS soft segment, which is denote H-D-BD, was also studied for comparison. The effects of soft segment type and ion incorporation on the physical properties, surface properties, and plateled adhesion are discussed. The ionic polyurethaneureas exhibited poor phase separation, a smaller fraction of PTMO present at the surface, and a smaller contact angle. On the other hand, it also showed a larger fraction of PDMS present at the surface and a higher water absorption value than its nonionic counterpart. H-D-BD had more phase-separated structure, a larger fraction of PDMS present at the surface, and larger contact angle but lower water absorption value than the PTMO-containing polyurethaneureas. The in vitro platelet adhesion experiments indicated that the ionic groups, especially for carboxylate, and surface enrichment PDMS soft segment could effectively inhibit platelet adhesion.

Swyer-James syndrome complicated by lung abscess

Swyer-James syndrome, a rare disease with unilateral hyperlucent lung due to bronchiolitis obliterans and pulmonary artery hypoplasia, generally develops after lower respiratory tract infection during early childhood. Invasive procedures, including bronchoscopy and angiography, are often necessary for a definitive diagnosis. We report a 17-year-old man admitted because of cystic bronchiectasis complicated by lung abscess. Chest roentgenography showed the typical findings of Swyer-James syndrome. Noninvasive magnetic resonance angiography was used to confirm hypoplasia of the right pulmonary artery. The patient received antibiotic therapy, underwent a right lower lobectomy for the lung abscess, and recovered.

Chromosomal damage in long-term residents of houses contaminated with cobalt-60

Chromosomal translocations in people who have lived in houses contaminated with radiation were substantially raised compared with controls. Retrospective biological dosimetry indicated cumulative exposures less than 1.0 Gy, which were lower than values derived from physical measurements.

Biphasic modulation of ryanodine binding to sarcoplasmic reticulum vesicles of skeletal muscle by Zn2+ ions

With the use of a [(3)H]ryanodine binding assay, the modulation of skeletal muscle ryanodine receptor (RyR1) by Zn(2+) was investigated. In the presence of 100 microM free Ca(2+) concentration ([Ca(2+)](f)) as activator, the equilibrium [(3)H]ryanodine binding to heavy sarcoplasmic reticulum vesicles was biphasically modulated by Zn(2+). The binding was increased by a free Zn(2+) concentration ([Zn(2+)](f)) of less than 1 microM; a peak binding, approx. 140% of the control (without added Zn(2+)) was obtained at 0.3 microM [Zn(2+)](f). An inhibitory effect of Zn(2+) became obvious with a [Zn(2+)](f) of more than 1 microM; the [Zn(2+)](f) for producing half inhibition was 2.7+/-0.5 microM (mean+/-S.D.). Scatchard analysis indicated that the increase in the binding induced by low [Zn(2+)](f) was due to a decrease in K(d), whereas both an increase in K(d) and a possible decrease in B(max) were responsible for the decrease in binding induced by high [Zn(2+)](f). The binding in the presence of micromolar [Zn(2+)](f) showed a biphasic time course. In the presence of 3 microM [Zn(2+)](f), after reaching a peak with an increased rate of initial binding, the binding gradually declined. The decline phase could be prevented by decreasing [Zn(2+)](f) to 0.5 microM or by adding 2 mM dithiothreitol, a thiol-reducing agent. The [Ca(2+)](f) dependence of binding was changed significantly by Zn(2+), whereas Ca(2+) had no clear effect on the [Zn(2+)](f) dependence of binding. Moreover, some interactions were found in the effects between Zn(2+) and other RyR1 modulators. It is indicated that Zn(2+) can modulate the activation sites and inactivation sites for Ca(2+) on RyR1. The physiological significance of the effects of Zn(2+) on ryanodine binding is discussed.

Synthesis, characterization and platelet adhesion studies of novel ion-containing aliphatic polyurethanes

Two novel ion-containing aliphatic polyurethanes based on 4,4'-methylene dicyclohexyl diisocyanate (H12MDI), polytetramethyl oxide (PTMO) were synthesized using either sulfonated or carboxylated chain extender. The nonionic polyurethane chain extended with 1,4-butanediol, which is denoted as H-M-BD, was synthesized. Pellethane, a biomedical-grade polyurethane, was also studied for comparison. The polymer's bulk, surface, and platelet-contacting properties were studied using Fourier transform infrared spectrophotometry, differential scanning calorimetry, water absorption analysis, electron spectroscopy for chemical analysis, static contact angle analysis, and in vitro platelet adhesion experiments. The effects of ion incorporation on the morphology, surface properties and blood compatibility are discussed. Unlike MDI-based Pellethane, all H12MDI-based polyurethanes are not composed of crystalline hard segment domain but are amorphous. The ionic polyurethanes exhibit a smaller fraction of hydrogen-bonded carbonyl groups, poorer phase separation, smaller fraction of PTMO residing at the surface, and smaller contact angle; however, significant higher water absorption value than H-M-BD and Pellethane. The in vitro platelet adhesion experiments indicated that ion incorporation, especially for carboxylate, significantly reduced the number and the degree of activation of the adherent platelets.

Reentrant tachyarrhythmias in right atria of cardiomyopathic versus healthy Syrian hamster

We studied the role of acetylcholine (ACh) and calcium overload in the induction of atrial flutter or atrial fibrillation (AF) in right atria from 34 normal male Syrian hamsters (F1B) and 33 cardiomyopathic Syrian hamsters (BIO 14.6) associated with focal myocardial necrosis. Action potential (AP) was recorded with conventional microelectrode techniques and twitch force by a transducer. ACh (0.1, 1 and 10 microM) induced high-frequency AF (around 33 Hz) along with tension oscillations and contracture in 7 of 12 normal hamster atria. These effects of ACh were abolished by tetrodotoxin or quinidine as well as by atropine. In contrast, ACh induced AF only in 1 of 12 myopathic atria. In both normal and myopathic atria, ACh induced similar changes in AP duration, spontaneous rate and force. The effects of calcium overload were tested by means of a high [Ca(2+)](o) (8.1 mM) low [K(+)](o) (1 mM) solution in another series of experiments. This solution also induced incidence of AF higher in normal (10/12) than in myopathic atria (4/12). The calcium load was also increased by high-frequency pacing (32 Hz for 3 or 30 s): AF occurred in normal atria (5/8), but not in myopathic atria (0/8). Measurement of the refractory period revealed a longer refractory period in myopathic than in control atria. We concluded that the lower incidence of AF in myopathic atria was probably due to their longer refractory period and the associated focal myocardial necrosis which then hindered the establishment of such a reentrant rhythm.

A comparison of air displacement plethysmography with three other techniques to determine body fat in healthy adults

BACKGROUND

This study compared air displacement plethysmography (ADP), which relies on measurements of body density to estimate body fat, with three other techniques that measure body composition: (1) hydrostatic weighing (HW), which also measures body density; (2) bioelectrical impedance (BIA), which determines electrical resistance and total body water to estimate fat-free mass; and (3) dual-energy x-ray absorptiometry (DXA), which measures bone, fat, and fat-free soft tissue masses.

METHODS

ADP, HW, BIA, and DXA were performed on 20 healthy volunteers (10 males and 10 females). The subjects were within 20% of ideal body weight, 31.1 +/- 1.8 years of age, and 75.4 +/- 2.7 kg with body mass index values of 25.2 +/- 0.9 (kg/m2) and percent body fat by ADP ranging from 6.0% to 41.0%.

RESULTS

Percent body fat measurements by the four methods were highly correlated (r > .90, p < .0001). Mean body fat as determined by ADP, HW, BIA, and DXA were 23.4% +/- 2.3%, 23.9% +/-1.8%, 23.1% +/- 1.9%, and 26.4% +/- 2.4%, respectively (* p < .05 vs ADP). There was a significantly positive slope (+0.23) for the individual differences vs the average of ADP and HW percent body fat, demonstrating a slightly negative difference at lower body fat levels and a slightly positive difference at greater body fat levels. Although the average percent body fat determined by ADP was similar to that by HW for the entire population, there was a significant gender difference with the average body fat measured by ADP being 16% less in males and 7% greater in females than that determined by HW.

CONCLUSIONS

Body fat measurements using ADP were highly correlated with those using HW, BIA, and DXA across a relatively wide range of body fat levels in healthy adults. These results support the utility of ADP as a relatively new technique in the estimation of percent body fat in healthy adults. However, the error associated with gender and the level of body fat is not negligible and requires further investigation.

Constrictive pericarditis in patients with tuberculous pericarditis

Constrictive pericarditis is a complication of tuberculous pericarditis that necessitates surgical intervention. In this study, we sought to identify echocardiographic features that could predict the development of constrictive pericarditis from acute or subacute pericarditis. From January 1988 through May 1998, all patients with a discharge diagnosis of tuberculous pericarditis were enrolled in the study, and their clinical features, laboratory findings, sonographic images, treatments, and outcomes were analyzed. Tuberculous pericarditis was demonstrated on the basis of positive Mycobacterium tuberculosis cultures from pericardial fluid or tissue in 11 patients; pericardial biopsy specimens demonstrating caseating granulomas in seven; and bacteriologic or histologic evidence of active extra-pericardial tuberculosis in conjunction with major pericardial effusion in four. Seventeen patients had effusive tuberculous pericarditis and five had constrictive tuberculous pericarditis as the initial diagnosis. The echocardiographic findings of effusive pericarditis were classified as shaggy-type effusion (n = 8) and non-shaggy-type effusion (9). Shaggy effusion was defined as the presence of multiple fibrin strands or a mass-like exudate coating the pericardium and bridging the pericardial effusion. Non-shaggy effusion was characterized by an anechoic pericardial space with or without a thickened pericardium, but no shaggy exudative coating. The mean duration between the onset of symptoms and diagnosis was longer in patients with shaggy-type effusion (39.6 +/- 8.7 vs 21.0 +/- 13.9 days, p < 0.05). Prednisolone (20-30 mg/d) was used in addition to antituberculous chemotherapy in 11 of the 17 patients with effusive pericarditis. Two of 11 patients (18%) who received steroid therapy, and five of the six patients (83%) who did not, developed constrictive pericarditis in the following year. Therefore, we concluded that adjuvant therapy with steroids significantly decreased the risk of constrictive pericarditis in patients with non-shaggy, but not shaggy, effusion.

Development and validation of a measurement system for assessment of energy expenditure and physical activity in Prader-Willi syndrome

OBJECTIVE

The morbid obesity associated with Prader-Willi syndrome (PWS) may result from either excessive energy intake or reduced energy expenditure (EE). In this report, we describe the development and validation of an Activity-Energy Measurement System (AEMS) to measure EE and physical activity components in an environment approximating free-living conditions.

RESEARCH METHODS AND PROCEDURES

The AEMS consists of a live-in, whole-room indirect calorimeter equipped with a novel force platform floor system to enable simultaneous measurements of EE, physical activity, and work efficiency during spontaneous activities and standardized exercises. Free-living physical activity and estimated free-living EE are measured using portable triaxial accelerometers individually calibrated in each subject during their stay in the AEMS.

RESULTS

Representative data from two PWS patients and two matched control (CTR) subjects displayed EE during their inactive lifestyles.

DISCUSSION

This combination of methods will allow the quantification of daily EE and its components, the amount and energy cost of physical activity, and the relationships between body composition and EE, in order to determine their roles in the development and maintenance of the morbid obesity in PWS.

Corticotropin-releasing factor enhances brain-derived neurotrophic factor gene expression to facilitate memory retention in rats

In the present study, we investigated the effects of corticotropin-releasing factor (CRF) injected into the dentate gyrus (DG) of the hippocampus on brain-derived neurotrophic factor (BDNF) mRNA expression and studied whether N-methyl-D-aspartate (NMDA) receptor mediates the effects of CRF on BDNF mRNA expression in the DG. Since both CRF and BDNF gene expressions are involved in memory processing in rats, we further investigated whether CRF facilitates memory retention through enhanced BDNF mRNA expression in the hippocampus. Effect of direct BDNF injection to the DG on retention performance in rats was also assessed. Results indicated that intra-DG CRF injection produced a dose-dependent (0.1 microg, 1.0 microg and 10 microg) increase in BDNF mRNA level, while intra-DG MK801 injection produced a dose-dependent (0.08 microg, 0.2 microg and 2.0 microg) decrease in BDNF mRNA expression in the DG. MK801, at a dose having no significant effect alone (0.08 microg), significantly antagonized the effect of CRF on BDNF mRNA expression. On the other hand, CRF (1.0 microg) consistently and markedly improved retention performance in rats in an inhibitory avoidance learning task. BDNF antisense oligonucleotide treatment, at a concentration which did not affect retention performance alone (0.5 mM), blocked the memory-enhancing effect of CRF. However, direct and chronic BDNF injection to the DG did not improve memory performance in rats. These results together suggest that at least one of the mechanisms responsible for the memory-facilitating effect of CRF is mediated through enhanced BDNF mRNA expression in the hippocampus. The lack of an effect of intra-DG BDNF injection on memory retention is also discussed.

Detection of IgA against Epstein-Barr virus BZLF-1 replication activator (ZEBRA) in sera of nasopharyngeal carcinoma patients with a recombinant ZEBRA protein

BACKGROUND

Epstein-Barr virus (EBV) is closely associated with nasopharyngeal carcinoma (NPC). An EBV-encoded immediate-early antigen, BZLF-1 replication activator (ZEBRA) initiates EBV replication and expression in all NPC tumors. In this study, we investigated whether immunoglobulin A (IgA) against ZEBRA is present in the sera of patients with NPC, and whether it was able to be determined by enzyme-linked immunosorbent assay (ELISA) using a recombinant ZEBRA prepared from Escherichia coli.

METHODS

A polymerase chain reaction-amplified cDNA fragment of the ZEBRA gene was inserted into the expression vector of E coli under the control of an IpL promoter. E coli bacteria containing the CI857 gene served as host to overexpress the ZEBRA protein by heat induction. Recombinant ZEBRA was collected by mechanical disruption of the bacteria, purified by column chromatography, and analyzed by SDS-PAGE and Western blot assay using sera from NPC patients. The recombinant ZEBRA was used to develop the ELISA to detect IgA against ZEBRA.

RESULTS

The amount of ZEBRA produced comprised 30% of total E coli protein. Western blot assay confirmed that affinity of the recombinant ZEBRA to IgA antibody was preserved. IgA against ZEBRA was shown to be positive by ELISA in 36 of 40 NPC sera, but in only nine of 55 patients with other head and neck malignancies, and two of 35 normal individuals. For serologic diagnosis of NPC, the sensitivity of IgA/ZEBRA detected by ELISA was 90% and the specificity was 87.4%.

CONCLUSIONS

A recombinant ZEBRA was produced at high levels in E coli and retained affinity to IgA against ZEBRA. The recombinant ZEBRA was successfully used to develop an ELISA for the detection of IgA against ZEBRA. The high sensitivity and specificity of IgA against ZEBRA show that the ELISA is feasible for serologic diagnosis of NPC.

Iatrogenic hyperadrenocorticism in 28 dogs

Twenty-eight dogs with iatrogenic hyperadrenocorticism were studied. The most common clinical signs were cutaneous lesions (27/28), polydipsia (21/28), polyuria (19/28), and lethargy (16/28). The most predominant findings on biochemical profile were elevated alkaline phosphatase (ALP, 15/28) and alanine transferase (ALT, 14/28); hypercholesterolemia (14/28); elevated aspartate transferase (AST, 12/28); and elevated triglycerides (12/18). Baseline cortisol levels of all 28 dogs were at the lower end of the reference range and exhibited suppressed or no response to adrenocorticotropic hormone (ACTH) stimulation. The mean time for each dog to show initial improvement of clinical signs after corticosteroid withdrawal was six weeks, with another mean time of 12 weeks to demonstrate complete remission.

Comparison of air-displacement plethysmography with hydrostatic weighing and bioelectrical impedance analysis for the assessment of body composition in healthy adults

BACKGROUND

Over the past decade, considerable attention has been paid to accurately measuring body composition in diverse populations. Recently, the use of air-displacement plethysmography (AP) was proposed as an accurate, comfortable, and accessible method of body-composition analysis.

OBJECTIVE

The purpose of this study was to compare measurements of percentage body fat (%BF) by AP and 2 other established techniques, hydrostatic weighing (HW) and bioelectrical impedance analysis (BIA), in adults.

DESIGN

The sample consisted of healthy men (n = 23) and women (n = 24). %BF was measured by AP, HW, and BIA.

RESULTS

In the total group, %BF(AP) (25.0+/-8.9%) was not significantly different from %BF(HW) (25.1+/-7.7%) or %BF(BIA) (23.9+/-7.7%), and %BF(AP) was significantly correlated with %BF(HW) (r = 0.944, P < 0.001) and with %BF(BIA) (r = 0.859, P < 0.01). Compared with HW, AP underestimated %BF in men (by -1.24+/-3.12%) but overestimated %BF in women (by 1.02+/-2.48%), indicating a significant sex effect (P < 0.05). The differences in estimation between AP and BIA and between BIA and HW were not significantly different between the sexes.

CONCLUSION

AP is an accurate method for assessing body composition in healthy adults. Future studies should assess further the cause of the individual variations with this new method.

[Potentiation of caffeine-induced contracture by raising extracellular potassium in frog skeletal muscle]

The effect of raising extracellular potassium ([K+]o) on caffeine contracture was investigated, using small bundles dissected from frog anterior tibialis muscle. Elevating [K+]o from the control of 2 mmol/L to 10 or 25 mmol/L significantly potentiated the contracture induced by 3 mmol/L caffeine. The potentiation represented by PKC/PC, where PKC and PC are the peak tension of the caffeine contracture evoked in high and normal [K+]o respectively, was dependent on [K+]o and the duration of conditioning high K+ exposure. With 10 mmol/L [K+]o, the potentiation was gradually increased by prolonging conditioning exposure up to 10 min. On the contrary, with 25 mmol/L [K+]o the potentiation reached a maximum within only 1 min, and then subsided to the control. These different time courses of PKC/PC could not be accounted for by high K+ induced depolarization, but were in general consistence with the time courses of the change in myoplasmic free calcium induced by corresponding high [K+]o. It is suggested that, at least in frog skeletal muscle, the high [K+]o induced potentiation of caffeine contracture is mainly due to an increase of myoplasmic free calcium.

11C-acetate clearance in nasopharyngeal carcinoma

This study assessed 11C-acetate turnover (clearance) in nasopharyngeal carcinoma (NPC). Data were acquired by dynamic PET after the intravenous injection of 4.625 MBq.kg-1 body weight of 11C-acetate for 30 min. Tomograms were reconstructed and evaluated visually. A time-activity curve of the nasopharynx and neck was generated and the clearance rate of 11C-acetate from the nasopharynx in the slow phase and from NPC was calculated using 0.693/T1/2. Ten patients with nasopharyngeal carcinoma and nine normal subjects were studied. The clearance of 11C-acetate from the normal nasopharynx was rapid and biexponential, in contrast to the rapid uptake followed by extremely slow clearance in patients with NPC. The clearance rate (mean +/- S.D.) was 0.0074 +/- 0.0042 in NPC and 0.0263 +/- 0.0152 in controls in the slow phase, being significantly different between the two groups with no overlap. All nasopharyngeal carcinomas were clearly visualized, in contrast to no obvious retention in the normal nasopharynx. Our initial results indicate that 11C-acetate clearance can be used to differentiate nasopharyngeal carcinoma from a normal nasopharynx. This finding may lead to new applications of 11C-acetate in oncology.

Energy expenditure determined by self-reported physical activity is related to body fatness

OBJECTIVE

Activity self-reports are a commonly used tool in assessing daily physical activity (PA) and associated energy expenditure (EE). This study examined the effect of relative body fatness (%BF) on differences between self-reported and measured duration and associated EE in healthy adults.

RESEARCH METHODS AND PROCEDURES

Men and women (n = 115, age 38+/-9 years), ranging in %BF from 7.9% to 58.9%, spent two separate days (normal and exercise) in a whole-room indirect calorimeter where EE was measured. While in the room calorimeter, subjects reported the type, intensity, and duration of each performed PA. The Compendium of Physical Activity was used to calculate the energy cost of each reported activity. The EE of all self-reported activities (EEr) was categorized into four intensity levels, synchronized, and compared with EE from the room calorimeter (EEm).

RESULTS

With increasing %BF, subjects significantly overestimated duration of more strenuous activities (> or =4.5), while underestimating moderate activities (2.5 to 4.4 metabolic equivalents (METs)). Misreporting of duration and/or intensity caused an overestimation or underestimation of PA-associated EE at these levels. Reported EE sleep was lower than measured EE sleep, although both had similar durations. As a result, total EEr was similar to EEm.

DISCUSSION

Individual variability of daily total PA and associated EE generated from self-reports in adults is high. Persons with a higher %BF report duration and/or intensity of moderate to high levels of PA with lower accuracy than leaner individuals. We conclude using the Compendium of Physical Activity is not suitable for the accurate estimation of self-reported EE of AA in adults with a higher %BF.

The significance of soluble interleukin-2 receptor in monitoring disease relapse in patients with nasopharyngeal cancer

BACKGROUND

Soluble interleukin-2 receptor alpha (sIL-2R alpha) is a well-known indicator of T-cell activation noted to be increasing in nasopharyngeal cancer. However, the significance of sIL-2R alpha in monitoring disease relapse is unclear. This study was initiated to address this issue.

METHODS

Serum of 56 patients with NPC, which underwent either primary, salvage, or palliative treatments, from 1992 to 1993 at the Cancer Center, Veterans General Hospital-Taipei, were collected from our serum bank. According to their disease status at the time of study, at least two years after last treatments, the 56 patients were divided into four groups. The remission group represented those in remission at the time of study (n = 24). The metastasis group represented those with distant metastasis present at the time of study (n = 17). The recurrence group represented those with locoregional recurrence present at the time of study (n = 11). The combined group represented those with locoregional recurrence as well as distant metastasis (n = 4). The seral sIL-2R alpha concentrations of the 56 NPC patients were determined with enzyme-linked immunoabsorbent assay. The combined group was excluded in our statistical analysis. We performed statistical analysis on the differences of paired serum sIL-2R alpha concentrations between different periods of the diseases. The first analysis was on the differences of sIL-2R alpha concentrations between diagnosis and post-radiotherapy periods for 13 out of 24 patients in the remission group and 7 out of 11 patients in the recurrence group. The second analysis was on the differences of sIL-2R alpha concentration between follow-up before detection-of-relapse and after detection-of-relapse for 5 out of 17 patients in the metastasis group and six out of 11 patients in the recurrence group.

RESULTS

The first statistical analysis revealed no significant differences of sIL-2R alpha concentrations for the remission group (P = 0.946) and the recurrence group (P = 0.156) between diagnosis and post-radiotherapy periods. The second statistical analysis revealed no significant differences of sIL-2R alpha concentrations between before and after detection-of-relapse for the recurrence group, neither (P = 0.438). The results for the metastasis group were different. The sIL-2R alpha concentrations were shown to increase after the detection of metastasis for the 5 paired samples from the metastasis group, although the Wilcoxon signed ranks test on the differences only showed borderline significance (P = 0.063).

CONCLUSIONS

Our findings show that sIL-2R alpha would be of no value in monitoring the development of locoregional recurrence but might be useful in monitoring distant metastasis. Although our current limited data did not provide strong support for the role of sIL-2R alpha in monitoring metastasis, it might be delineated in the future by collecting more data.

Green tea epigallocatechin gallate shows a pronounced growth inhibitory effect on cancerous cells but not on their normal counterparts

(-)-Epigallocatechin gallate (EGCG), a catechin polyphenol compound, represents the main ingredient of green tea extract. Although EGCG has been shown to be growth inhibitory in a number of tumor cell lines, it is not clear whether the effect is cancer-specific. In this study we compared the effect of EGCG on the growth of SV40 virally transformed WI38 human fibroblasts (WI38VA) with that of normal WI38 cells. The IC50 value of EGCG was estimated to be 120 and 10 microM for WI38 and WI38VA cells, respectively. Thus, EGCG at 40 microM completely inhibited the growth of WI38VA cells, but had little or no inhibitory effect on the growth of WI38 cells. Similar differential growth inhibition was also observed between a human colorectal cancer cell line (Caco-2), a breast cancer cell line (Hs578T) and their respective normal counterparts. EGCG at a concentration range of 40-200 microM induced a significant amount of apoptosis in WI38VA cultures, but not in WI38 cultures, as determined by terminal deoxynucleotidyl transferase assay. After exposure to EGCG at 200 microM for 8 h, more than 50% of WI38VA cells in a confluent culture became apoptotic. In contrast, less than 1% of WI38 cells displayed apoptotic labeling under the same condition. EGCG did not affect the serum-induced expression of c-fos and c-myc genes in normal WI38 cells. However, it significantly enhanced their expression in transformed W138VA cells. It is possible that differential modulation of certain genes, such as c-fos and c-myc, may cause differential effects of EGCG on the growth and death of cancer cells.

Hydroxyl radical formation in chondrocytes and cartilage as detected by electron paramagnetic resonance spectroscopy using spin trapping reagents

Chondrocytes have been shown to produce superoxide and hydrogen peroxide, suggesting possible formation of hydroxyl radical in these cells. In this study, we used electron spin resonance/spin trapping technique to detect hydroxyl radicals in chondrocytes. We found that hydroxyl radicals could be detected as alpha-hydroxyethyl spin trapped adduct of 4-pyridyl 1-oxide N-tert-butylnitrone (4-POBN) in chondrocytes stimulated with phorbol 12-myristate 13-acetate in the presence of ferrous ion. The formation of hydroxyl radical appears to be mediated by the transition metal-catalyzed Haber-Weiss reaction since no hydroxyl radical was detected in the absence of exogenous iron. The hydroxyl radical formation was inhibited by catalase but not by superoxide dismutase, suggesting that the hydrogen peroxide is the precursor. Cytokines, IL-1 and TNF enhanced the hydroxyl radical formation in phorbol 12-myristate 13-acetate treated chondrocytes. Interestingly, hydroxyl radical could be detected in unstimulated fresh human and rabbit cartilage tissue pieces in the presence of iron. These results suggest that the formation of hydroxyl radical in cartilage could play a role in cartilage matrix degradation.

Enhanced glial cell line-derived neurotrophic factor mRNA expression upon (-)-deprenyl and melatonin treatments

Glial cell line-derived neurotrophic factor (GDNF) has been shown to be a preferentially selective neurotrophic factor for dopamine (DA) neurons. In the present study, we have examined the distribution of GDNF mRNA expression in several major DA-containing cell body and terminal areas and the regulation of GDNF mRNA expression upon various pharmacological treatments. Results indicated that there is a relatively higher GDNF mRNA level in neurons of the nigrostriatal and mesolimbic dopaminergic pathways. Upon chronic 1-methyl-4-phenyl1,2,3,6-tetrahydropyridine (MPTP) treatment (30 mg/ kg, i.p., for 7 days), DA level was decreased, whereas GDNF mRNA expression was increased in the striatum, suggesting that more GDNF is synthesized and expressed to cope with the neurotoxin insult. Furthermore, among several DA neuron protective and/or therapeutic agents examined, both intrastriatal injections of (-)-deprenyl (1.25 microg and 2.5 microg) and melatonin (30 microg, 60 microg, and 120 microg) significantly enhanced GDNF mRNA expression in the striatum, whereas the same concentrations of (-)-deprenyl did not affect monoamine oxidase B (MAOB) activity, although it increased glutathione peroxidase (GPx) and/or superoxide dismutase (SOD) activities. Similarly, the same concentrations of melatonin did not alter SOD or GPx activities, except that the highest dose of melatonin (120 microg) increased lipid peroxidation in the striatum. Conversely, GM1 ganglioside injection (45 microg) lacked of an effect on GDNF mRNA expression. Together, these results suggest that both (-)-deprenyl and melatonin up-regulate GDNF gene expression at threshold doses lower than that needed for altering MAOB activity and/or the antioxidant enzyme systems, respectively. These results provide new information on the neuroprotective and therapeutic mechanisms of (-)-deprenyl and melatonin on DA neurons.

Lung cancer in pregnancy: report of two cases

Lung cancer during pregnancy is rare, although the number of case reports has been increasing in recent years. Herein, we describe two cases of lung carcinoma complicating pregnancy with different presentations and outcomes, and review the relevant literature. The first case involved a 31-year-old patient with squamous cell carcinoma with multiple bone metastases. The initial symptoms were productive cough and dyspnea on exertion during the second trimester of pregnancy, to which the patient paid little attention. Chemoradiation was started 1 month postpartum, soon after the diagnosis was made, but with little response. She died at home several days after palliative radiotherapy. The second case involved a 34-year-old patient with poorly differentiated lung carcinoma with brain metastasis. Left hemiparesis had developed initially during the third trimester. She underwent excision of the metastatic brain tumor and received radiotherapy to the left lung tumor and brain. The patient is still alive after a follow-up period of more than 1 year. Delayed diagnosis may be the main problem in the management of lung cancer during pregnancy, because of misinterpretation of common respiratory symptoms and physicians' reluctance to use radiologic imaging studies owing to concerns over the safety of the fetus. Thus, we suggest chest radiographs with abdominal lead shielding for pregnant patients with protracted cough and hemoptysis. Treatment of unresectable lung cancer during pregnancy generally consisted of radiation therapy with or without chemotherapy in previous reports, but the optimal therapy is still unknown, owing to inadequate case numbers and insufficient follow-up data.

Prognostic factors and therapeutic options of radiotherapy in pediatric brain stem gliomas

BACKGROUND

A retrospective analysis was made to clarify the relationship between prognosis, radiation dose and survival of brain stem gliomas.

METHODS

From 1983 to 1995, 22 children with brain stem tumors were treated by radiotherapy in the Veterans General Hospital-Taipei. Twelve patients had pathology proof and the remainder were diagnosed by computerized tomography and/or magnetic resonance imaging. Seven patients had postoperative radiotherapy. Fifteen patients had radiotherapy as primary management, five of whom had adjuvant chemotherapy. All patients received 4000-7060 cGy, either in conventional daily or hyperfractionated twice daily radiotherapy. Survival from date of diagnosis was calculated by the Kaplan-Meier method. Univariate analyses and multivariate analyses were calculated by the log rank test and the Cox proportional hazard model, respectively.

RESULTS

Most patients showed improvement following treatment. The overall 2-year survival rate was 55.5% with a median survival of 27.1 months. Two-year survival for patients with primary management of operation and radiotherapy (n = 7), radiotherapy alone (n = 10) and radiotherapy with adjuvant chemotherapy (n = 5) were 66.7, 50 and 53.3%, respectively. In univariate analysis, the study revealed that the growth pattern of tumors and the simultaneous presence of cranial neuropathy and long tract sign were significant prognostic factors (P = 0.017 and 0.036). A trend of better outcome with radiation dose > 6600 cGy and the hyperfractionation scheme was also noted in our study (P = 0.0573 and 0.0615). However, only the hyperfractionation scheme was also noted in our study (P = 0.0573 and 0.0615). However, only the hyperfractionation scheme showed significance in multivariate analyses (P = 0.0355). Survival was not significantly affected by age, gender or method of diagnosis.

CONCLUSION

Radiotherapy appears to be an effective treatment modality of brain stem tumors. Patients with both cranial neuropathy and long tract signs had a poorer outcome. Hyperfractionated radiotherapy may give better local control and lead to better survival.

Green tea epigallocatechin gallate shows a pronounced growth inhibitory effect on cancerous cells but not on their normal counterparts

(-)-Epigallocatechin gallate (EGCG), a catechin polyphenol compound, represents the main ingredient of green tea extract. Although EGCG has been shown to be growth inhibitory in a number of tumor cell lines, it is not clear whether the effect is cancer-specific. In this study we compared the effect of EGCG on the growth of SV40 virally transformed WI38 human fibroblasts (WI38VA) with that of normal WI38 cells. The IC50 value of EGCG was estimated to be 120 and 10 microM for WI38 and WI38VA cells, respectively. Thus, EGCG at 40 microM completely inhibited the growth of WI38VA cells, but had little or no inhibitory effect on the growth of WI38 cells. Similar differential growth inhibition was also observed between a human colorectal cancer cell line (Caco-2), a breast cancer cell line (Hs578T) and their respective normal counterparts. EGCG at a concentration range of 40-200 microM induced a significant amount of apoptosis in WI38VA cultures, but not in WI38 cultures, as determined by terminal deoxynucleotidyl transferase assay. After exposure to EGCG at 200 microM for 8 h, more than 50% of WI38VA cells in a confluent culture became apoptotic. In contrast, less than 1% of WI38 cells displayed apoptotic labeling under the same condition. EGCG did not affect the serum-induced expression of c-fos and c-myc genes in normal WI38 cells. However, it significantly enhanced their expression in transformed W138VA cells. It is possible that differential modulation of certain genes, such as c-fos and c-myc, may cause differential effects of EGCG on the growth and death of cancer cells.

Primary pulmonary plasmacytoma with lobar consolidation: an unusual presentation

Extramedullary plasmacytoma is a rare form of plasma cell tumor that frequently involves the upper respiratory tract. Primary pulmonary plasmacytoma is even more rare. The usual presentation of primary pulmonary plasmacytoma is a solitary pulmonary nodule. We describe the case of a 58-year-old woman who presented with the chief complaints of progressive dyspnea on exertion, cough, and subsequently, hemoptysis. The main finding on chest imaging studies, including plain radiography, sonography, computed tomography, and magnetic resonance imaging, was consolidation of the right middle lobe. Percutaneous transthoracic lung biopsy of the right middle lobe demonstrated sheets of atypical plasma cells. Immunohistochemical study showed IgA lambda monoclonality. A bone marrow study and whole body bone scan showed normal findings. To the best of our knowledge, this is the first reported case of primary pulmonary plasmacytoma presenting with lobar consolidation of the lung but without a well-defined tumor mass.