Latency change estimation for evoked potentials via frequency selective adaptive phase spectrum analyzer

This paper addresses the problem of detecting and estimating latency changes in evoked potentials (EP's). EP's have been widely used to quantify neurological system properties. Transient and time-varying changes in latency may indicate impending neurological injury. Traditional time averaging and correlation methods for EP latency estimation are inefficient under low signal-to-noise ratio (SNR) and/or strong periodic interference conditions. This paper proposes an adaptive phase spectral time delay estimation method to detect and estimate the time-varying latency changes when both the SNR and the signal-to-interference ratio (SIR) are low. A theoretical analysis and computer simulation demonstrate that the proposed method can track the time-varying latency changes effectively and accurately when both the SNR and the SIR are as low as -5 dB. The method is also suitable for real time detection and estimation of the latency changes.

Quantification of injury-related EEG signal changes using distance measures

Novel indicators based on distance measures are developed and compared to quantify changes in electroencephalogram signal resulting from hypoxic-asphyxic injury. An injury index is derived based on the measures. The Itakura distance-based index is found to have the highest correlation with the long-term outcome as measured by the neurological deficit scores.

[Clinicopathologic study of 11 patients with Paget's disease of scrotum]

OBJECTIVE

To probe the relationship of clinicopathologic presentations and prognosis of Paget's disease primarily involving the scrotum.

METHODS

11 cases of scrotal Paget's disease were studied retrospectively from 1984 to 1997. PAS was stained and EMA, S-100, HMB45, CEA and CA15-3 were immunostained in all cases for the differential diagnosis from Bowen's disease and malignant melanoma.

RESULTS

Six of 11 cases involved hair follicle and/or sweat glands, and 3 cases involved dermis (one had metastasis of left superficial and deep inguinal lymph nodes, and left internal iliac lymph nodes). Paget's cells were positive for PAS (11/11), EMA (11/11), CEA (6/11), CA15-3 (11/11), and negative for S-100, HMB45. Wide local excision of the lesions was performed in 10 of 11 patients both for primary disease and recurrent disease. 3 of the 10 patients underwent lymph nodes resection and metastasis was found in 1 case pathologically. One patient accepted chemotherapy and died, from respiratory insufficiency after one month. The other 10 patients were followed up for 6 to 127 months and no patient died of Paget's disease.

CONCLUSIONS

Involvement of hair follicles and sweat glands by Paget's cell does not influence the prognosis.However, invasion of dermis by Paget's cells may suggest possible metastasis.

Flow cytometric analysis of BHRF1 expression prohibiting apoptosis induced by radiation

The Epstein-Barr virus gene BHRFI has homology with proto-oncogene bcl-2, which can protect cells from apoptosis. In order to investigate the effect of BHRF1 expression on the anti-apoptotic ability of nasopharyngeal carcinoma (NPC) cells after irradiation, a high-BHRF1 expression vector was constructed and transfected into the NPC cell line CNE2. Then, the alteration of proliferation and apoptosis in the cells was tested by flow cytometry after cobalt 60 irradiation. The results showed that BHRF1 expression could increase G1 delay and decrease the cell percentage in S phase before irradiation, and reduce the apoptotic rate of CNE2 cells and increase the cell percentage in S phase after irradiation. The results suggest that BHRF1 expression is able to alter the cell cycle and protect CNE2 cells from apoptosis induced by radiation.

Study of activity of promoter from mouse alpha 2(I) procollagen gene

OBJECTIVE

To clarify the segment and sequence in mouse alpha 2(I) procollagen gene which are responsible for high transcriptional activity during fibrogenesis.

METHODS

This study was focused on further fractional analysis of 2 kb-length mouse alpha 2(I) procollagen gene promoter activity. Six chimeric genes were constructed in which various lengths of sequences between 2000 bp upstream of the start of transcription of the mouse alpha 2 (I) procollagen gene and 54 bp downstream of this site were fused to chloramphenicol acetyltransferase (CAT) reporter gene. These recombinant plasmids were transfected transiently to collagen-producing cells (NIH/3T3) and non-collagen-producing cells (COS7) with liposomal transfection method. The activities of putative promoters were observed and compared by means of CAT measurement in the transfected cells.

RESULTS

The highest and partial cell specific CAT expression was observed in construction driven by -780 to bp fragment. The construction containing sequence deleted the proximal 500 bp from the transcription start site and part of exon I, and resulted in the lowest CAT expression.

CONCLUSIONS

Some essential elements might exist in the 500 bp fraction proximal to transcription start site and part of exon I in mouse alpha 2(I) procollagen gene. The high potential promoter sequence between -780 bp from the start of transcription site and bp from this site is of great significance in our following study of searching for specific DNA-binding proteins in activated collagen-producing cells.

A contiguous 3-Mb sequence-ready map in the S3-MX region on 21q22.2 based on high- throughput nonisotopic library screenings

Progress in complete genomic sequencing of human chromosome 21 relies on the construction of high-quality bacterial clone maps spanning large chromosomal regions. To achieve this goal, we have applied a strategy based on nonradioactive hybridizations to contig building. A contiguous sequence-ready map was constructed in the Down syndrome congenital heart disease (DS-CHD) region in 21q22.2, as a framework for large-scale genomic sequencing and positional candidate gene approach. Contig assembly was performed essentially by high throughput nonisotopic screenings of genomic libraries, prior to clone validation by (1) restriction digest fingerprinting, (2) STS analysis, (3) Southern hybridizations, and (4) FISH analysis. The contig contains a total of 50 STSs, of which 13 were newly isolated. A minimum tiling path (MTP) was subsequently defined that consists of 20 PACs, 2 BACs, and 5 cosmids covering 3 Mb between D21S3 and MX1. Gene distribution in the region includes 9 known genes (c21-LRP, WRB, SH3BGR, HMG14, PCP4, DSCAM, MX2, MX1, and TMPRSS2) and 14 new additional gene signatures consisting of cDNA selection products and ESTs. Forthcoming genomic sequence information will unravel the structural organization of potential candidate genes involved in specific features of Down syndrome pathogenesis.

[The effect of combined endocrine therapy on prostate and testis]

OBJECTIVE

To study the pathological changes of the effect of combined endocrine therapy on normal prostate, benign prostatic hyperplasia, prostatic adenocarcinoma and testis.

METHODS

11 radical prostatectomy specimens, 3 core-needle biopsies of prostate and 3 testes obtained after at least 3 months of enatone-flutamide inhibition therapy were studied. Step-section was performed on radical specimens and average 16 sections per case were reviewed. PSA, PSAP and AE1/AE3 were immunostained on 14 cases of prostate cancer and a comparative study pre- and post-treatment was made.

RESULTS

No residual tumor was recognized in 2 cases. Such characteristic changes were found in 9 cases as prominent acinar atrophy, decreased ratio of acini to stroma, stromal fibrosis, squamous metaplasia of carcinoma, cytoplasmic vaculation, nuclear shrinkage, and nucleolar shrinkage. No apparent change was discovered in 3 cases. Secretory epithelial atrophy and basal cell hyperplasia were the popular change in BPH and normal prostate. The expressions of both PSA and PSAP were markedly reduced in prostate carcinoma and nonneoplastic glands. Pathological downstaging of the tumor was not found statistically. Epithelial atrophy also existed in seminal vesicles and Leydig cells of the testes after hormone therapy.

CONCLUSIONS

Combined endocrine therapy results in histologically distinctive changes that can be found in both nonneoplastic and neoplastic prostate tissue. However, the drugs can not eradicate prostate cancer completely. Testis atrophy is the direct action of the therapy.

New axonemal dynein heavy chains from Tetrahymena thermophila

Two dyneins can be extracted from Tetrahymena ciliary axonemes. The 22S dynein contains three heavy chains (HC), sediments at 22S in a sucrose gradient, and makes up the outer arms. The 14S dynein contains two to six HCs, sediments at 14S, and is thought to contribute to formation of the inner arms. We have identified two large proteins that are extracted from Tetrahymena axonemes with high salt and that sediment together at approximately 18S. The two large proteins cleave when subjected to UV light in the presence of ATP and vanadate, suggesting both proteins are dynein HC. Antibodies against one of the 18S HCs do not recognize 22S dynein HCs. Antibodies to 22S dynein HC do not bind appreciably to 18S dynein photocleavage fragments. Taken together, these results indicate that the large proteins that sediment at 18S are axonemal dynein heavy chains.

[The influences of interleukin-1 beta converting enzyme expression on the biologic characteristics of ovarian cancer cells]

OBJECTIVE

To investigate the effects of interleukin-1 beta converting enzyme (ICE) gene on the biologic characteristics of ovarian cancer cells.

METHODS

A 1.3 Kilobase human ICE cDNA with 5' and 3' untranslated sequences was cloned into the EcoR I site of pLXSN retrovirus vector in sense orientation. After that, the recombinant plasmid pLXSN-ICE was transferred to virus-packing cell PA317 by electroporation method. And then the retrovirus containing human ICE cDNA generated by these PA317 cells were used to transfect human ovarian cancer cell lines, AO and 3AO.

RESULTS

After being transfected with these retrovirus, the number of the clones obtained after G418 resistance selection is far less than that of controlled groups with plasmid pLXSN. The growth rate of these transfected cells was significantly suppressed in comparison with the parental cell line. Apoptosis was also found in these cells. After the transfection cancer cells were inoculated subcutaneously in nude mice, the tumor growth was significantly inhibited.

CONCLUSION

It suggest that human ICE gene can suppress the phenotype and tumorigenicity in nude mice of ovarian cancer cell lines AO and 3AO.

Preliminary clinical application of contrast-enhanced MR portography

The clinical application of contrast enhanced (CE) MR was evaluated. A total of 66 CE MR portograms were obtained by performing fast imaging with steady procession (FISP) technique on a 1.5-T Siemens magnetom vision. A maximum intensity projection algorithm was also employed to include all vessels in a single image. The patency of portal venous system, the presence and extent of varices were also evaluated. The results showed that all images had diagnostic quality. Main portal vein (MPV) and its 4th-6th level intrahepatic branches were visualized in 10 normal persons serving as control. The diameter of MPV, splenic vein and superior mesenteric vein was 1.02 +/- 0.21, 0.8 +/- 0.15, 0.8 +/- 0.26 cm respectively, which were significantly lower than that in portal hypertension patients (1.38 +/- 0.27, 1.26 +/- 0.18, 1.24 +/- 0.18 cm, respectively). In 23 preoperative cases of portal hypertension, dilated portal vein and tortuous enlarged splenic vein were found in 23 cases; esophageal and coronary varices in 12 and 19 cases, respectively. In 7 postoperative re-examined cases with portal hypertension, the flow velocity and flow of MPV were decreased in all cases and esophageal varices could still be observed in 3 cases. New vessels appeared in the great curvature of stomach in 2 cases. In 20 cases of liver carcinoma, occlusion of MPV or its intrahepatic branches were showed in 14, compression and dislocation of intrahepatic portal vein were found in 6. In other 6 cases, 2 were splenic venous thrombosis and 4 were tumors in the intestine or retro-peritoneum. It is concluded that three-dimensional CE MR portography is an accurate technique for evaluating the portal venous system. It is a reliable and noninvasive technique that can provide important information for the evaluation of patients' condition before TIPSS and liver transplantation.

Gradient- and sensitivity-enhanced heteronuclear multiple-quantum correlation spectroscopy

A gradient- and sensitivity-enhanced HMQC experiment has been developed. The sensitivity of the experiment is increased by factors of the square root of 2 and 2 over the conventional and gradient-enhanced HMQC experiments, respectively. This improvement is achieved by retaining both the x and the y magnetization components in the indirectly detected dimension. This experiment will be particularly useful in NMR studies of large biomolecules as the relaxation time of the multiple-quantum coherence is much longer than that of the single-quantum coherence in the slow motion limit.

Structure of the E2 DNA-binding domain from human papillomavirus serotype 31 at 2.4 A

The papillomaviruses are a family of small double-stranded DNA viruses which exclusively infect epithelial cells and stimulate the proliferation of those cells. A key protein within the papillomavirus life-cycle is known as the E2 (Early 2) protein and is responsible for regulating viral transcription from all viral promoters as well as for replication of the papillomavirus genome in tandem with another protein known as E1. The E2 protein itself consists of three functional domains: an N-terminal trans-activation domain, a proline-rich linker, and a C-terminal DNA-binding domain. The first crystal structure of the human papillomavirus, serotype 31 (HPV-31), E2 DNA-binding domain has been determined at 2.4 A resolution. The HPV DNA-binding domain monomer consists of two beta-alpha-beta repeats of approximately equal length and is arranged as to have an anti-parallel beta-sheet flanked by the two alpha-helices. The monomers form the functional in vivo dimer by association of the beta-sheets of each monomer so as to form an eight-stranded anti-parallel beta-barrel at the center of the dimer, with the alpha-helices lining the outside of the barrel. The overall structure of HVP-31 E2 DNA-binding domain is similar to both the bovine papillomavirus E2-binding domain and the Epstein-Barr nuclear antigen-1 DNA-binding domain.

Regulation of classic and alternative bile acid synthesis in hypercholesterolemic rabbits: effects of cholesterol feeding and bile acid depletion

The effect of cholesterol feeding (3 g/day) on bile acid synthesis was examined in 10 New Zealand white rabbits (NZW), 8 Watanabe heterozygous and 10 homozygous rabbits with partial and complete deficiencies of LDL receptors. After 10 days of cholesterol feeding, bile fistulas were constructed and bile acid pool sizes were measured. Cholesterol feeding increased plasma and hepatic cholesterol levels in all rabbit groups. Baseline bile acid pool sizes were smaller (P < 0.01) in heterozygotes (139 +/- 3 mg) and homozygotes (124 +/- 30 mg) than NZW rabbits (254 +/- 44 mg). After feeding cholesterol, bile acid pool sizes doubled with increased cholic acid synthesis in NZW and, to a lesser extent, in Watanabe heterozygous rabbits but not in homozygotes. Baseline cholesterol 7alpha-hydroxylase activity in NZW and heterozygotes declined 69% and 53% (P < 0.001), respectively, after cholesterol feeding. Sterol 27-hydroxylase activity reflecting alternative bile acid synthesis increased 66% (P < 0.01) in NZW and 37% in Watanabe heterozygotes but not in homozygotes after feeding cholesterol. Bile fistula drainage stimulated cholesterol 7alpha-hydroxylase activity but not sterol 27-hydroxylase activity in all three rabbit groups. These results demonstrated that dietary cholesterol increased hepatic sterol 27-hydroxylase activity and alternative bile acid synthesis to expand the bile acid pool and inhibited cholesterol 7alpha-hydroxylase in NZW and in Watanabe heterozygous rabbits but not in homozygotes with absent hepatic LDL receptor function. Thus, in rabbits, sterol 27-hydroxylase is up-regulated by the increased hepatic cholesterol that enters the liver via LDL receptors whereas cholesterol 7alpha-hydroxylase is controlled by the circulating hepatic bile acid flux.

[Effects of ligustrazine on myocardium and coronary artery]

OBJECTIVE

To study the effects of ligustrazine on mechanical electricity in guinea pig ventricular papillary muscles and on contraction of pig coronary artery.

METHOD

Standard glass microelectrode technology; electrophysiological method; and blood vessel perfusion were used.

RESULT

1. ligustrazine(3-100 mumol/L) suppressed the action potential duration (APD) and the force of contraction (FC) of the fast action potentials (FAP), as well as the action potential amplitude (APA), APD, FC and the maximal upstroke velocity(Vmax) of the slow action potentials (SAP). 2. ligustrazine (3.0 mmol/L) induced SAP and contraction, but failed in beta-adrenoreceptor blocked muscles. Elevation of[Ca2+]o increased the action potential amplitude (APA). 3. ligustrazine(10(-5)-5 x 10(-3) mol/L) decreased the contractile response to high KCl in pig coronary artery.

CONCLUSION

Ligustrazine might affect the inward current of myocardial cells through beta-adrenoreceptor, and the diastolizing effect of ligustrazine on coronary artery might have nothing to do with the exciting beta-adrenoreceptor.

[Expression and significance of Fas/APO-1 and bcl-2 protein in renal cell carcinoma]

OBJECTIVE

To investigate the role of Fas/APO-1 and bcl-2 in occurrence and progression of renal cell carcinoma.

METHOD

Immunohistochemistry method was used to detect the expression of Fas/APO-1 and bcl-2 protein in 35 cases of renal cell carcinoma tissues and 26 cases of normal renal tissues.

RESULT

The expression rate of Fas/APO-1 protein in renal cell carcinoma tissues was 57.14%, significantly lower than that in normal renal tissues (84.62%) (P < 0.05), and the intensity of expression was also lower. The expression rate of bcl-2 protein reached 80.00%, much higher than that in normal renal tissues (53.85%) (P < 0.05).

CONCLUSION

Both Fas/APO-1 and bcl-2 take part in the occurrence and progression of renal cell carcinoma.

[Effects of excessive zinc in fodder on brain development and abilities of learning and memory and their mechanisms in young rats]

OBJECTIVE

To study the effects of excessive zinc in fodder on brain development and abilities of learning and memory and to explore their mechanisms in young rats.

METHODS

Animal models with excessive zinc were established in young Wistar rats during their lactation period. Rats were divided into five groups, Groups ZE1 and ZE2 were fed with excessive zinc, Group AL was freely fed with Flanagna fomula fodder added with zinc sulfate, Group PF was matched pair of Group ZE2 and Group ZE2R was fed with fodder same as Group AL after weaning. Ultrastructure was observed with electron microscopy, their free amino acids, nitrous oxide and somatostatin were measured with neurobiochemical methods, and their abilities to learn and memorize were examined.

RESULTS

Weight of cerebrum and hippocampus in the rats reduced and zinc levels in their serum and hippocampus raised with the increase of zinc content in their fodder. Acute avoidance response (AAR) and movement in the young rats fed with excessive zinc in Groups ZE1 and ZE2 were obviously lower than in Groups AL and PF. AAR was significantly lower in Group ZE2R than that in Groups AL and PF, but significantly higher than that in Group ZE2. There was no significant difference in AAR between Groups PF and AL, but more movement was observed in them. Nitrous oxide in hippocampus raised and somatostatin decreased in Group ZE2, and total amount of excitatory and inhibitory amino acids in brain tissues raised, especially for glutamic acid. Neurones, gliocytes and organella in the CA1 region of hippocampus in the Group ZE2 showed degeneration, necrosis and rupture of synaptic bolus to varied extent.

CONCLUSION

Excessive zinc in fodder could significantly affect brain development and functions in young rats with multiple mechanisms.

[Apoptosis of renal cell carcinoma and apoptotic related genes bcl-2 and bax]

OBJECTIVE

To explore the mechanism of renal cell carcinoma (RCC).

METHOD

We detected the apoptotic status and the expression of apoptotic related gene bcl-2 and bax protein in 48 cases of RCC with TdT-mediated dUTP-biotin nick end labeling (TUNEL) and immunohistochemistry methods.

RESULT

22 cases showed low expression of bcl-2 protein with an average apoptotic index (AI) of 1.35 and 26 cases had high expression of bcl-2 with an AI of 1.04 (P < 0.05). 34 cases showed low expression of bax protein with average AI of 1.03 and 14 cases had high expression of bax protein with an average AI of 1.63 (P < 0.01). The stronger bcl-2 expression, the weaker bax expression and the less number of apoptotic cells.

CONCLUSION

both bcl-2 and bax take part in the occurrence and progression of RCC.

[Primary epididymal tumors]

OBJECTIVE

To improve the diagnosis of primary epididymal tumors.

METHOD

In 23 primary epididymal tumors (22 benign and 1 malignant), 14 were adenomatoid tumors, 6 were leiomyomas, 1 was multiple fibrous pseudomonas and 1 was sclerosing hemangioma. Epididymal adenocarcinoma was seen in a 57-year-old man.

RESULT

Epididymal tumors might be easily misdiagnosed as epididymal tuberculosis, chronic epididymis and spermatocele. Apart from certain benign clinical characteristics, benign epididymal tumors could be diagnosed by B-ultrasonography and aspiration biopsy. Most malignant tumors of epididymis presented as rapidly growing scrotal masses and cured by the removal of tumors or the whole epididymis of the same side. 19 of 22 cases were free from recurrence.

CONCLUSION

Malignant epididymal tumors should be treated as malignant tumors of testis and their prognosis is extremely poor.

[Low semi-cystectomy in treating trigone of bladder neck carcinoma]

OBJECTIVE

To resect the tumor in trigone and bladder neck and remain urination function.

METHOD

A new procedure low segmental-cystectomy which includes resection of the trigone of bladder, prostate, seminal vesicles, extremity of ureter, was performed on 8 patients aged 28 to 57 years.

RESULT

The patients were followed up for 6 months to 3 years. No recurrent tumor and metastasis were found, and urination function was normal.

CONCLUSION

This procedure is superior to Bricker's operation, Kock pouch bladder and ileal neo-bladder. The patients enjoy good life quality after operation.