Germ cell tumors express a specific alpha-fetoprotein variant detectable by isoelectric focusing

BACKGROUND

Many nonseminomatous germ cell tumors (NSGCTs) express elevated levels of serum alpha-fetoprotein (AFP), which is widely used for diagnosis and monitoring therapy. Alpha-fetoprotein is also expressed in patients with hepatocellular carcinoma (HCC). In these sera, several variants, some highly specific, recently have been detected by isoelectric focusing.

METHODS

Sera were collected from nine patients with NSGCTs, five pregnant women, and five patients with HCC. After isoelectric focusing, the proteins were transferred to nitrocellulose membrane by blotting and incubated with polyclonal rabbit antihuman AFP conjugated with horseradish peroxidase. The enhanced chemiluminescence detection system and Hyperfilm-ECL were used to render the protein bands visible and each was quantified as a percentage of the total AFP using a densitometer.

RESULTS

Isoelectric focusing of serum alpha-fetoprotein from the patients with NSGCTs (four testicular, five mediastinal) revealed a consistent pattern characterized by a specific band (band +III). A second band (band +II) that is also seen in sera from patients with hepatocellular carcinoma was present in all patients. The overall pattern was distinct from that of AFP from HCC and that produced during late pregnancy. The two characteristic bands (AFP +II and +III) were responsible for the great majority of total AFP in these patients; estimation of serial sera in patients undergoing treatment showed that total and "malignant" AFP changed in parallel. Banding patterns, apart from one patient, were identical in patients with testicular and mediastinal NSGCTs.

CONCLUSION

NSGCTs tumors express a highly consistent and specific pattern of AFP variants. More detailed analysis of AFP patterns in larger numbers of patients may provide further insight into the cellular heterogeneity of germ cell tumors.

Coping and psychological distress of Chinese parents of children with Down syndrome

Coping and correlates of psychological distress of Chinese parents of children with Down syndrome were examined and compared to parents of children with language delays or no disabilities. Individual parent scores were used for analyses, with groups and gender of child and parent as independent factors. Down syndrome group parents reported the most frequent use of avoidance coping style, followed by parents of the language delay and no disabilities groups. Compared to parents in the no disabilities group, the other parents reported a higher level of psychological distress, were less optimistic, felt less self-efficacious, and engaged in more frequent use of self-reliance coping style. Main effects for parent gender revealed that mothers engaged in more frequent use of self-reliance, avoidance, and seeking social support coping styles. Mothers also reported a higher level of distress but lower levels of optimism and self-mastery. Intercorrelations among variables showed that avoidance coping style and self-mastery emerged as the two robust correlates of parental distress.

Investigating the effects of opioid drugs on electrocortical activity using wavelet transform

Fetal electrocortical activity (ECoG) is characterized by two distinct patterns: HVSA (high voltage, slow activity) and LVFA (low voltage, fast activity). Using the wavelet transform (WT), we recently reported that the frequency characteristics of these two ECoG patterns undergo significant maturational changes prior to birth (Akay et al. 1994a). We now report that fetal ECoG can also be significantly affected by pharmacological agents. In this paper, we compared the effects of two opioid drugs (morphine and [D-Pen2, D-Pen5]-enkephalin, DPDPE) on fetal ECoG, using the chronically instrumented fetal lamb model. Morphine was infused intravenously (i.v.) at 2.5 mg/h, while DPDPE was infused into the lateral cerebroventricle (i.c.v.) at 30 micrograms/h. The ECoG was analyzed using WT. We performed multi-resolution decomposition for four sets of parameters D2j where -1 < j < -4. The four series WTs represent the detail signal bandwidths: (1) 16-32 Hz, (2) 8-16 Hz, (3) 4-8 Hz, (4) 2-4 Hz. The data were subjected to statistical analysis using the Kolmogorov-Smirnov (KS) test. Both morphine and DPDPE resulted in a significant increase in power in the first wavelet band, while power was reduced in the second, third and fourth wavelet bands. In addition, both drugs resulted in a disruption of the normal cyclic pattern between the two ECoG patterns. There was a difference in the time course of action between morphine and DPDPE. This is the first occasion in which continuous ECoG has been subjected to rigorous statistical analysis. The results suggest that the WT-KS method is most suitable for quantitating changes in the ECoG induced by pharmacological agents.

Generation and quenching of singlet molecular oxygen by aggregated bacteriochlorophyll d in model systems and chlorosomes

Both photogeneration and quenching of singlet oxygen by monomeric and aggregated (dimeric and oligomeric) molecules of bacteriochlorophyll (BChl) d have been studied in solution and in chlorosomes isolated from the green photosynthetic bacterium Chlorobium vibrioforme f. thiosulfatophilum. The yield of singlet-oxygen photogeneration by pigment dimers was about 6 times less than for monomers. Singlet oxygen formation was not observed in oligomer-containing solutions or in chlorosomes. To estimate the efficiency of singlet oxygen quenching an effective rate constant for (1)O2 quenching by BChl molecules (kq (M)) was determined using the Stern-Volmer equation and the total concentration of BChl d in the samples. In solutions containing only monomeric BChl, the kq (M) values coincide with the real values for (1)O2 quenching rate constants by BChl molecules. Aggregation weakly influenced the kq (M) values in pigment solutions. In chlorosomes (which contain both BChl and carotenoids) the kq (M) value was less than in solutions of BChl alone and much less than in acetone extracts from chlorosomes. Thus (1)O2 quenching by BChl and carotenoids is much less efficient in chlorosomes than in solution and is likely caused primarily by BChl molecules which are close to the surface of the large chlorosome particles. The data allow a general conclusion that monomeric and dimeric chlorophyll molecules are the most likely sources of (1)O2 formation in photosynthetic systems and excitation energy trapping by the long wavelength aggregates as well as (1)O2 physical quenching by monomeric and aggregated chlorophyll can be considered as parts of the protective system against singlet oxygen formation.

Time-frequency analysis of the electrocortical activity during maturation using wavelet transform

In this study, we introduce the wavelet transform (WT) as a method for characterizing the maturational changes in electrocortical activity in 24 fetal lambs ranging from 110-144 days gestation (term 145 days). The WT, based on multiresolution signal decomposition, is free of assumptions regarding the characteristics of the signal. The approximation of the electrocortical activity at resolutions varying from 2j+1 to 2j can be extracted by decomposing the signal on a wavelet orthonormal basis of L2(R). We performed multiresolution decomposition for four sets of parameters D2j, where -1 < j < -4. The four series WT represent the detail signal band-widths: (1) 16-32 Hz, (2) 8-16 Hz, (3) 4-8 Hz, (4) 2-4 Hz. The data were divided into three groups according to gestational age: 110-122 days (early), 123-135 days (middle), and 136-144 days (late). In the early group, the power was highest in the fourth signal bandwidth, with relatively low power in the other bands. Increase in gestational age was characterized by increased power in all four bandwidths. Comparison of the cumulative distribution function of the power in the four wavelet bands confirmed the presence of two statistically different patterns in all three age groups. These two patterns correspond to the visually identified patterns of HVSA (high-voltage slow activity) and LVFA (low-voltage fast activity). The earliest development change occurred in HVSA, with progressive increase in power in the 2-8 Hz band. Later changes occurred in LVFA, with a significant increase in power in the 16-32 Hz band.(ABSTRACT TRUNCATED AT 250 WORDS)

Optical spectroscopy of a highly fluorescent aggregate of bacteriochlorophyll c

Bacteriochlorophyll (BChl) c and a similar model compound, Mg-methyl bacteriopheophorbide d, form several types of aggregates in nonpolar solvents. One of these aggregates is highly fluorescent, with a quantum yield higher than that of the monomer. This aggregate is also unusual in that it shows a rise time in its fluorescence emission decay at certain wavelengths, which is ascribed to a change in conformation of the aggregate. An analysis of fluorescence depolarization data is consistent with either a linear aggregate of four or five monomers or preferably a cyclic arrangement of three dimers.

The role of ultrasound and computed tomography in the evaluation of parotid masses

A prospective sonographic study of 40 patients with symptomatic parotid masses detected all of their 48 lesions (sensitivity 100%). Computed tomography (CT) detected 47 lesions (sensitivity 97.5%). Ultrasound correctly characterized all benign tumours and inflammatory lesions and four out of five malignant tumours. Deep compartment involvement was accurately delineated in 10 (25%) patients but in two patients the extraparotid tumour origin could only be detected by CT. Ultrasound is a sensitive, non-invasive investigation of parotid masses. Computed tomography (CT) or magnetic resonance should be reserved for lesions that involve the deep compartment of the gland and cannot be separated from the parapharyngeal space or skull base.

A general cone-beam reconstruction algorithm

Considering the characteristics of the X-ray microscope system being developed at SUNY at Buffalo and the limitations of available cone-beam reconstruction algorithms, a general cone-beam reconstruction algorithm and several special versions of it are proposed and validated by simulation. The cone-beam algorithm allows various scanning loci, handles reconstruction of rod-shaped specimens which are common in practice, and facilitates near real-time reconstruction by providing the same computational efficiency and parallelism as L.A. Feldkamp et al.'s (1984) algorithm. Although the present cone-beam algorithm is not exact, it consistently gives satisfactory reconstructed images. Furthermore, it has several nice properties if the scanning locus meets some conditions. First, reconstruction within a midplane is exact using a planar scanning locus. Second, the vertical integral of a reconstructed image is equal to that of the actual image. Third, reconstruction is exact if an actual image is independent of rotation axis coordinate z. Also, the general algorithm can uniformize and reduce z-axis artifacts, if a helix-like scanning locus is used.

Helix-loop-helix transcription factors E12 and E47 are not essential for skeletal or cardiac myogenesis, erythropoiesis, chondrogenesis, or neurogenesis

E12 and E47 are two non-tissue-specific helix-loop-helix (HLH) transcription factors encoded by the E2A gene. Previous studies suggested that they are involved in regulation of differentiation in many tissue types including muscle, blood, and nerve through direct heterodimer interactions with tissue-specific HLH proteins. To gain further genetic insight into the functions of E12 and E47 during cell differentiation, we mutated both copies of the E2A gene in mouse embryonic stem (ES) cells and then tested the effect on differentiation in vitro. We find that the ES cells lacking functional E12 and E47 are capable of differentiating into both skeletal and cardiac muscle, erythrocytes, neurons, and cartilage that the same extent as wild-type cells. These results indicate that the E2A gene is not essential for differentiation of these cell types and suggest that redundant genes may control these developmental pathways.

The stress distribution of the lumbar spine and disc degeneration

A three-dimensional finite element model of the lumbar motion segment was developed to study the effect of disc degeneration upon stress distribution in the lumbar spine. The results showed that after degeneration of the intervertebral disc, the stress distribution and load transmission of the lumbar spine are significantly changed. It is concluded that these changes provide a biomechanical basis for understanding the etiology of spinal canal stenosis and nerve root entrapment.

Stress distribution and bone density in the lumbar spine

The stress distribution of the lumbar spine was analyzed with a mechanical model of the lumbar motion segment constructed by a three-dimensional finite element method, and the results were compared with the corresponding bone density represented by the value of CT. The results showed that the stress levels in the various parts of the lumbar spine were closely related to the CT values. The authors conclude that the dynamic balance of bone growth is maintained in large part by mechanical stress.

[Chemical constituents of Isodon albopilosus (C.Y. Wu et H.W. Li) Hara]

Five compounds have been isolated from the stems and leaves of Isodon albopilosus. On the basis of spectroscopic and chemical data, they were identified as macrocalyxin C, stearic acid, beta-sitosterol, ursolic acid and beta-sitosterol-beta-D-glucoside, respectively.

[Measurement of plasma malondialdehyde contents and erythrocyte superoxide dismutase activities in patients with chronic cor pulmonale]

We measured the contents of plasma MDA and erythrocyte SOD activities in patients with chronic cor pulmonale. The contents of malondialdehyde (MDA) increased; the superoxide dismutase (SOD) activities suppressed significantly and reoxygenation caused increases in the SOD activities in patients with acute attacks. But the changes of the contents of MDA and SOD activities did not appear in patients with stationary phase. These results indicate that oxygen free radicals may contribute to the physiopathological process of chronic cor pulmonale.

[Anti-anaphylactic pharmacological action of water-soluble constituents of Ginkgo biloba L. episperm]

Water-soluble constituents of Ginkgo biloba episperm 100 or 200 mg/kg po given to mice inhibited passive cutaneous allergic response and the same dose given to rats ip inhibited mast cell degranulation. It antagonized the contractile effect of isolated guinea pig ileum smooth muscles induced by the antigen. It inhibited the deliverance of SRS-A from anaphylactic lung of guinea pig.

Epstein-Barr virus genotypes associated with nasopharyngeal carcinoma in southern China

We have used probes representing approximately two-thirds of the Epstein-Barr virus (EBV) genome to examine genetic polymorphism of wild-type EBV directly detected in 28 nasopharyngeal carcinoma (NPC) tissues from Southern China. In the hypervariable regions containing reiterated sequences, this analysis showed that while naturally occurring viruses are genetically diverse, only one genotype was detectable in each tumor specimen. Unique variants in NPC were detected in four regions of the EBV genome. Two of these appeared significant in their distribution. The type C variant resulting from loss of a BamHl site between the BamHl W1* and l1* regions was prevalent among isolates from Southern China, but not so common in the United States. An "f" variant having an extra BamHl site in the BamHl F region was almost exclusively detected in only Asian NPC biopsies.

End-point nystagmus and ocular drift: an experimental and theoretical study

End-point nystagmus (EPN) and ocular drift during eccentric fixation were investigated in five normal subjects. All had EPN during prolonged eccentric fixation, two had sustained EPN within a few seconds of fixating an eccentric target. Our data show that the occurrence of EPN was determined by the velocity of slow phase ocular drift. Drift velocities greater than 1 deg/sec elicited sustained EPN or fatigue EPN while drift velocities lower than 0.3 deg/sec did not elicit EPN. Slow phase drift velocity increased with eccentricity and fixation duration and decreased with visual feedback. Computer simulations and theoretical analysis suggest that the reduction in drift eye movement velocity during fixation of a visible target, as compared to drift eye movement velocity during attempted fixation of a remembered target in darkness, is mainly due to the smooth pursuit system.