Magnetic resonance imaging indexes of therapeutic efficacy of recombinant tissue plasminogen activator treatment of rat at 1 and 4 hours after embolic stroke

With use of magnetic resonance imaging (MRI), the effects of early and delayed treatment of embolic stroke in rat with recombinant tissue plasminogen activator (rt-PA) were investigated. Rats with embolic stroke were treated with rt-PA at 1 (n = 9) or 4 (n = 7) hours after stroke onset or were untreated (n = 15). Diffusion-weighted imaging, perfusion-weighted imaging, and T2-weighted imaging were performed before and after embolization from 1 hour to 7 days. No significant differences were detected in the relative areas with low cerebral blood flow (CBF), apparent diffusion coefficient of water (ADCw), and T2 between the 4-hour treated group and the untreated group. Significant decreases in the average relative areas with low CBF were detected in the 1-hour treated group from 4 to 48 hours after embolization as compared with the untreated group. The increase in T2 in the 1-hour treated group was significantly lower than in the untreated and 4-hour treated groups. A significant increase in ADCw was detected in the 1-hour treated group at 3 and 24 hours after embolization as compared with the untreated and 4-hour treated groups. Secondary embolization was detected by both MRI and laser scanning confocal microscopy. The data suggest that MRI can detect the efficacy of rt-PA treatment and secondary ischemic damage.

[HBV transmission from father to foetus and HBV DNA in tissues outside the liver]

OBJECTIVE

To study the possibility of HBV Transmission from father to foetus and HBV DNA in tissues outside liver.

METHODS

Paired sera were from 8 HBV man carriers whose wives were negative for HBVM and 8 foetuses who were infected with HBV in the womb. S gene nt 451-660 nucleotide, C gene nt 2,022-2,321 nucleotide were directly sequenced.

RESULTS

The homology of HBV sequence between father and foetus was very high. The mutations of 491, 494, 530, 546 and 581 nucleotide in the S gene caused 113, 114, 126, 131 and 143 amino acid substitution. HBV DNA can be detected in the tissues outside liver of foetus.

CONCLUSION

HBV transmission from father to foetus may be present. HBV DNA in tissues outside liver of foetus can be detected.

Genetically fluorescent melanoma bone and organ metastasis models

We report here the establishment and metastatic properties of bright, highly stable, green fluorescent protein (GFP) expression transductants of the B16 mouse malignant melanoma cell line and the LOX human melanoma line. The highly fluorescent malignant melanoma cell lines allowed the visualization of skeletal and multiorgan metastases after i.v. injection of B16 cells in C57BL/6 mice and intradermal injection of LOX cells in nude mice. The melanoma cell lines were transduced with the pLEIN expression retroviral vector containing the GFP and neomycin resistance genes. Stable B16F0 and LOX clones expressing high levels of GFP were selected stepwise in vitro in levels of G418 of up to 800 microg/ml. Extensive bone and bone marrow metastases of B16F0 were visualized by GFP expression when the animals were sacrificed 3 weeks after cell implantation. Metastases for both cell lines were visualized in many organs, including the brain, lung, pleural membrane, liver, kidney, adrenal gland, lymph nodes, skeleton, muscle, and skin by GFP fluorescence. This is the first observation of experimental skeletal metastases of melanoma, which was made possible by GFP expression. These models should facilitate future studies of the mechanism and therapy of bone and multiorgan metastasis of melanoma.

[Expression of genes aroG and pheA in phenylalanine biosynthesis]

aroG and pheA genes, encoding 3-Deoxy-D-arabinoheptulonate-7-phosphate synthase(DS) and Chorismate mutase (CM)-prephenate dehydratase(PD) in the pathway of phenylalanine biosynthesis respectively, were amplified by polymerase chain reaction(PCR). The genes were assembled on the multicopy vectors and expressed in both Escherichia coli and Brevibacterium. The products of two gene were detected by SDS-PAGE. The activities of relevant enzymes were measured in the crude extract of the host strain. When aroG-pheA genes were introduced into E. coli p2392, the activities of DS, CM and PD were increased by 4.3-fold, 4.4-fold and 2.2-fold respectively. Whereas in the case of Brevibacterium flavum 2732, the activities of DS, CM and PD were increased by 12.3-fold, 2.3-fold and 5.6-fold, respectively. As the results, the overproduction of phenylalanine was brought about by using the genetic engineering strain of B. flavum.

Expression of intestinal trefoil factor in developing rat intestine

Intestinal trefoil factor (ITF or TFF3), a small peptide secreted at the mucosal surface by goblet cells throughout the mature intestine, appears to play important roles in the maintenance and repair of the intestinal mucosal barrier. To study the expression of TFF3 during development, intestinal tissues were collected from rats at different development stages and examined by Northern blot analysis, Western blot analysis and immunohistochemical staining for TFF3 mRNA and protein expression. The results demonstrate that rat TFF3 mRNA is not detected until the 17th gestational day (term = 22 days), the expression is greater on gestational day 20 and increased further postnatally. TFF3 protein is first detected by Western blotting and immunohistochemical staining on gestational day 20. Further increases in TFF3 protein expression are demonstrated at around the weaning period. In conclusion, significant expression of rat TFF3 commences late in gestation and its expression is relatively deficient in immature rats. Expression of TFF3 may be deficient in premature infants and, therefore, may have a role in the development of necrotizing enterocolitis.

[Detection of S-gene mutation strain in vertical transmission of HBV and its significance]

OBJECTIVE

To study S-gene mutation of hepatitis B virus (HBV) in its vertical transmission and its significance.

METHODS

Nucleotides of S-gene NT451-660 of HBV were sequenced with dideoxy end termination technique in four female and six male carriers without HBV markers in their spouses and in their intrauterine infected fetuses.

RESULTS

It was showed that homology of HBV nucleotide and amino acid sequences in the mothers, fathers and their fetuses was very high. Mutation at the sites 491, 494, 530, 546 and 581 of S-gene resulted in amino acid substitution at the sites 113, 114, 126, 131 and 143, respectively. Mutations at the sites 126 were detected in two pairs of mother or father and her or his fetuses and mutations at the sites 131 in four fetuses, respectively, including combined mutation at the site 143 in two fetuses.

CONCLUSION

Strains with S-gene mutation, mainly at the sites 126, 131 and 143, could be found in HBV vertical transmissions, which could cause failure in HB vaccine immunization.

Foot landing position during gait influences ground reaction forces

OBJECTIVE

The purpose of this study was to determine how foot landing position influenced the ground reaction forces of two coordinate systems during gait.

DESIGN

Values of ground reaction forces components as expressed in two coordinate systems (room, foot) were used to compare ground reaction forces of different foot landing position.

BACKGROUND

Non-neutral foot landing position during gait could influence the mechanics of the whole body motion and/or the foot-ankle complex and produce different ground reaction forces patterns compared to a neutral foot landing position.

METHODS

Thirty females were assigned to a foot landing group: toe-out, toe-in or neutral. Each participant walked 10 trials across a force platform while three-dimensional motion was captured.

RESULTS

No differences were observed for vertical or anteroposterior ground reaction forces variables between groups for either coordinate system. For medio-lateral forces of both coordinate systems, toe-out participants exhibited greater first lateral and second medial maximum forces and exhibited greater impulses.

CONCLUSION

For toe-out participants, greater medio-lateral ground reaction forces of the room coordinate system indicate excessive forces are generated by toe-out participants that do not contribute to moving the participant forward. Furthermore, medio-lateral loading on the foot increases proportionally with the degree of toe-out.

RELEVANCE

Establishing norms for clinical populations requires understanding of factors that can influence ground reaction force (GRF). Foot landing position (FLP) only affects the medio-lateral forces. Excessive toe-out landing has been surmised to be related to injury. Greater forces acting medio-laterally to the foot's long axis may have a relevant effect on in/eversion loading of the foot.

Development of a high metastatic orthotopic model of human renal cell carcinoma in nude mice: benefits of fragment implantation compared to cell-suspension injection

In this study we compared the metastatic rate of human renal cell carcinoma SN12C in two orthotopic nude mouse models: surgical orthotopic implantation (SOI) of histologically intact tumor tissue and cellular orthotopic injection (COI) of cell suspensions in the kidney. The primary tumors resulting from SOI were larger and much more locally invasive than primary tumors resulting from COI. SOI generated higher metastatic expression than COI. The differences in metastatic rates in the involved organs (lung, liver, and mediastinal lymph nodes) were 2-3 fold higher in SOI compared to COI (P < 0.05). Median survival time in the SOI model was 40 days, which was significantly shorter than that of COI (68 days) (P < 0.001). Histological observation of the primary tumors from the SOI model demonstrated a much richer vascular network than the COI model. Lymph node and lung metastases were larger and more cellular in the SOI model compared to COI. We conclude that the tissue architecture of the implanted tumor tissue in the SOI model plays an important role in the initiation of primary tumor growth, invasion, and distant metastasis. This study directly demonstrates that the implantation of histologically intact tumor tissue orthotopically allows accurate expression of the clinical features of human renal cancer in nude mice. This model should be of value in cancer research and antimetastatic drug discovery for renal cancer, a currently very poorly responding malignancy.

Recurrent varicose veins: patterns of reflux and clinical severity

Duplex scanning was used to determine patterns of recurrent varicose veins in 264 limbs and to relate these to clinical factors. All limbs had previously undergone sapheno-femoral ligation in the groin. A recurrent sapheno-femoral junction was present in 172 (65.2%). Incompetence was found in long or short saphenous veins in 232 limbs (87.9%), perforators in 176 (66.7%), and deep veins in 156 (59.1%). Residual long saphenous veins were present in 43.4% and 73.6% of limbs that were with and without stripped long saphenous veins, respectively. An incompetent thigh perforator was present in 14.0% and 15.3% of these two groups, respectively. Multiple sites of incompetence were observed in the majority (75.4%). In general, no particular reflux pattern in the groin was related to an increased incidence of ulceration. However, ulceration was more frequent in limbs with deep reflux to knee or below-knee levels. None of those with isolated reflux in the groin that was unrelated to the common femoral vein had ulceration. The pattern of reflux was unrelated to striping or non-striping of the long saphenous veins and the time since initial surgery. A history of deep vein thrombosis was invariably associated with some degree of deep reflux. A system of recurrent patterns in the groin is described for the purpose of surgical audit. In 15.1%, recurrence was attributed with some confidence to inadequate surgery. These results indicate that the pattern of recurrence is highly variable and often with multiple sites of incompetence. In a few instances, the pattern of recurrence was associated with specific clinical factors. A full work-up including duplex scanning is recommended.

Application of the polymerase chain reaction to detect fowl adenoviruses

The possibility of using the polymerase chain reaction (PCR) for the detection of fowl adenoviruses (FAdV) was tested. The optimal reaction parameters were evaluated and defined for purified genomic DNA of type 8 fowl adenovirus (FAdV-8), and then the same conditions were applied for nucleic acid extracted from infected cells. One hundred picograms of purified viral DNA, or 250 FAdV-8-infected cells, were detected by ethidium bromide staining of the PCR products in agarose gels. The sensitivity was increased to 10 pg purified viral DNA, or 25 infected cells, when the PCR products were hybridized with a specific labeled probe. Several field isolates of FAdV and the CELO virus (FAdV serotype 1) could be amplified by the same primers and conditions, but the size of the amplicons was smaller than that for the FAdV-8 PCR product. Other avian viruses and uninfected cell cultures tested negative.

[In vitro hepatic targeting tendency of galactosyl-anti CD3 McAb-TILS]

This study was undertaken to enhance the hepatic targeting tendency of tumor infiltrating lymphocytes (TILs) and hence to lower the recurrence rate of primary liver cancer after hepatectomy. Galactosyl-anti CD3McAb-TILs were prepared and then were incubated together with hepatocytes. Their interaction through asialoglycoprotein receptor-mediated mechanism was observed under the inverted phase contrast microscope. The carbohydrate density of galactosyl-anti CD3McAb and the combining rate of galactosyl-anti CD3McAb with TILs were measured. The results revealed that galactosyl-anti CD3 McAb-TIL obviously were adhered to hepatocytes. The carbohydrate density of galactosyl-anti CD3McAb was 62.18, and the combining rate of galactosyl-anti CD3McAb with TILs was 97.9%. The results suggested that in vitro hepatic targeting tendency of galactosyl-anti CD3McAb-TILs was satisfactory, and that the carbohydrate density of 62.18 and the combining rate of 97.9% ensured the effective use of TILs.

Regulation of autophosphorylation of Escherichia coli nitrogen regulator II by the PII signal transduction protein

The nitrogen regulator II (NRII or NtrB)-NRI (NtrC) two-component signal transduction system regulates the transcription of nitrogen-regulated genes in Escherichia coli. The NRII protein has both kinase and phosphatase activities and catalyzes the phosphorylation and dephosphorylation of NRI, which activates transcription when phosphorylated. The phosphatase activity of NRII is activated by the PII signal transduction protein. We showed that PII was also an inhibitor of the kinase activity of NRII. The data were consistent with the hypothesis that the kinase and phosphatase activities of two-component system kinase/phosphatase proteins are coordinately and reciprocally regulated. The ability of PII to regulate NRII is allosterically controlled by the small-molecule effector 2-ketoglutarate, which binds to PII. We studied the effect of 2-ketoglutarate on the regulation of the kinase and phosphatase activities of NRII by PII, using a coupled enzyme system to measure the rate of cleavage of ATP by NRII. The data were consistent with the following hypothesis: when not complexed with 2-ketoglutarate, PII cannot bind to NRII and has no effect on its competing NRI kinase and phosphatase activities. Under these conditions, the kinase activity of NRII is dominant. At low 2-ketoglutarate concentrations, PII trimers complexed with a single molecule of 2-ketoglutarate interact with NRII to inhibit its kinase activity and activate its phosphatase activity. However, at high 2-ketoglutarate concentrations, PII binds additional ligand molecules and is rendered incapable of binding to NRII, thereby releasing inhibition of NRII's kinase activity and effectively inhibiting its phosphatase activity (by failing to stimulate it).

A fluorescent orthotopic bone metastasis model of human prostate cancer

Here, we report a fluorescent spontaneous bone metastatic model of human prostate cancer developed by surgical orthotopic implantation of green fluorescent protein (GFP)-expressing prostate cancer tissue. Human prostate cancer PC-3 cells were transduced with the pLEIN expression retroviral vector containing the enhanced GFP and neomycin resistance genes. Stable GFP high-expression PC-3 clones were selected in vitro with G418, which were then combined and injected s.c. in nude mice. For metastasis studies, fragments of a single highly fluorescent s.c. growing tumor were implanted by surgical orthotopic implantation in the prostate of a series of nude mice. Subsequent micrometastases and metastases were visualized by GFP fluorescence throughout the skeleton, including the skull, rib, pelvis, femur, and tibia The central nervous system, including the brain and spinal cord, was also involved with tumor, as visualized by GFP fluorescence. Systemic organs, including the lung, plural membrane, liver, kidney, and adrenal gland, also had fluorescent metastases. The metastasis pattern in this model reflects the bone and other metastatic sites of human prostate cancer. Thus, this model should be very useful for the study and development of treatment for metastatic androgen-independent prostate cancer.

An ultra-metastatic model of human colon cancer in nude mice

An ultra-high metastatic model of human colon cancer was developed in order to represent highly malignant patient disease for which there is no current model. Surgical orthotopic implantation (SOI) of a histologically intact liver metastasis fragment derived from a surgical specimen of a patient with metastatic colon cancer was initially implanted in the colon, liver and subcutaneously in nude mice. This tumor did not metastasize for the first 10 passages. At the eleventh passage, the tumor exhibited metastasis from the colon to the liver, spleen, and lymph nodes. At this time, two selective passages were carried out by transplanting resulting liver metastases in the nude mice to the colon of additional nude mice. After these two passages, the tumor became stably ultra-metastatic and was termed AC3488UM. One-hundred percent of mice transplanted with AC3488UM with SOI to the colon exhibited local growth, regional invasion, and spontaneous metastasis to the liver, lymph nodes, and spleen. While the maximum size of the primary tumor was 0.9 g, the metastatic liver was over 9 times the weight of the normal liver with the maximum weight of the metastatic liver over 12 g. Liver metastases were detected by the tenth day after transplantation in all animals. Half the animals died of metastatic tumor 25 days after transplantation. Histological characteristics of AC3488UM tumor were poorly differentiated adenocarcinoma of colon. Mutant p53 is expressed heterogeneously in the primary tumor and more homogeneously in the liver metastasis suggesting a possible role of p53 in the liver metastasis. The human origin of AC3488UM was confirmed by positive fluorescence staining for in situ hybridization of human DNA. The AC3488 human colon-tumor model with its ultra-high metastatic capability in each transplanted animal, short latency and a short median survival period is different from any known human colon cancer model and will be an important tool for the study of and development of new therapy for highly metastatic human colon cancer.

Integrin-associated protein is a ligand for the P84 neural adhesion molecule

P84 (also known as SHPS-1, BIT, and SIRP) is a heterophilic adhesive membrane protein involved in receptor tyrosine kinase signaling that is found at synapses in the mammalian central nervous system and in non-neural tissues. We have identified a binding partner for P84 using an expression cloning strategy. Here we report that integrin-associated protein (IAP/CD47) is a predominant binding partner of P84. Immunohistochemistry reveals a virtually identical distribution of P84 and IAP in a variety of adult brain regions. Because IAP has been implicated in cell signaling in cells of the immune system, P84 and IAP represent a heterophilic binding pair that is likely to be involved in bi-directional signaling at the synapse and in other tissues.

[Experimental study on anti-cancer effect of Cantharidine derivatives and platinum complex]

OBJECTIVE

To certify the anti-tumor effects of the four Cantharidine derivatives and platinum complex on transplanted tumor in mice to search for new anti-tumor drugs.

METHODS

Complex of four Cantharidine derivatives (Dpt 1-15, Dpt 5-10, Dpt 12-3 and Dpt6-2) and platinum were given to tumor beating mice of transplanted S180 sarcoma, H22 solid hepatocarcinoma and ascites hepatocarcinoma through intraperitoneal or intravenous injection, and the effect of treatment on tumor weight and survival of animal were observed. Cisplatin was used as positive control and 0.9% normal saline used as negative control. All data were treated with t test.

RESULTS

All the four complex had anti-tumor effect. The inhibition rate of Dpt5-10 and Dpt1-15 on S180 sarcoma and H22 solid hepatocarcinoma and the survival prolongation rate of Dpt5-10 on H22 ascites hepatocarcinoma were similar to those of cisplatin. The toxicity of effective dose of Dpt1-15 was rather high.

CONCLUSIONS

Cantharidine derivatives and platinum complex is new effective anti-tumor drug, among them the Dpt5-10 is the most effective one. Further study for improving the solubility of drug is necessary and study the difference of cross resistance between the new complex and cisplatinum.

[Study on the contents of HBV DNA in sera of patients with hepatic diseases by QPCR technique]

In order to test the content of serum HBV DNA for evaluating the effectiveness of clinical antiviral treatment and the relation of serum HBV DNA level to state of illness and prognosis, a QPCR method of energy transfer in amplification by semi-nested fluorescein labeled primer was established. Serum HBV DNA contents of 63 cases of hepatic diseases with abnormal liver function were detected by QPCR, PCR and ELISA. The positive detectable rate of the three methods were compared. The results showed that the positive detectable rate of QPCR was 82.54%, PCR 71.43% and ELISA 63.50%. The detectable rate of QPCR was compared with PCR, and uniformity rate of the both methods was 88.89%, P < 0.05; the positive results of QPCR were compared with ELISA, and their uniformity rate was 80.95%, P < 0.05; when serum average content (mean +/- s) of HBV DNA by QPCR method was compared with serum average titer of HBV by ELISA method, serum HBV-DNA average content of the group in which both QPCR and ELISA were positive was much higher than that of the group of QPCR(+) and ELISA(-), P < 0.05; serum QPCR-HBV-DNA of 30 cases of healthy persons were all negative. The results indicated that QPCR method is of highest positive detectable rate and more specific in detecting serum HBV DNA and had no nonspecific amplifying reaction. It has the superiority of detecting low level serum HBV DNA.

[Chemical constituents of Cichorium intybus L]

OBJECTIVE

To investigate the chemical constituents of Cichorium intybus.

METHOD

Constituents were separated by means of solvent extraction and chromatography on silical gel. The structures were established by spectral analysis and chemical evidence.

RESULT

Seven compounds were isolated from the roots of C. intybus and four of them were identified as alpha-amyrin, taraxerone, baurenyl acetate and beta-sitosterol.

CONCLUSION

All the four compounds were obtained from the plant for the first time.

Widespread skeletal metastatic potential of human lung cancer revealed by green fluorescent protein expression

To understand the skeletal metastatic pattern of non-small cell lung cancer, we developed a stable high-expression green fluorescent protein (GFP) transductant of human lung cancer cell line H460 (H460-GFP). The GFP-expressing lung cancer was visualized to metastasize widely throughout the skeleton when implanted orthotopically in nude mice. H460 was transduced with the pLEIN retroviral expression vector containing the enhanced GFP and the neomycin (G418) resistance gene. A stable high GFP-expressing clone was selected in vitro using 800 microg/ml G418. Stable high-level expression of GFP was maintained in s.c.-growing tumors formed after injecting H460-GFP cells in nude mice. To use H460-GFP for visualization of metastasis, fragments of s.c.-growing H460-GFP tumors were implanted by surgical orthotopic implantation in the left lung of nude mice. Subsequent micrometastases were visualized by GFP fluorescence in the contralateral lung, plural membrane, and widely throughout the skeletal system including the skull, vertebra, femur, tibia, pelvis, and bone marrow of the femur and tibia. The use of GFP-expressing H460 cells transplanted by surgical orthotopic implantation revealed the extensive metastatic potential of lung cancer in particular to widely disseminated sites throughout the skeleton. This new metastatic model can play a critical role in the study of the mechanism of skeletal and other metastasis in lung cancer and in screening of therapeutics that prevent or reverse this process.

Enzymological characterization of the signal-transducing uridylyltransferase/uridylyl-removing enzyme (EC 2.7.7.59) of Escherichia coli and its interaction with the PII protein

The uridylyltransferase/uridylyl-removing enzyme (UTase/UR) of Escherichia coli plays an important role in the regulation of nitrogen assimilation by controlling the uridylylation state of the PII signal transduction protein (PII) in response to intracellular signals. The reversible uridylylation of PII indirectly controls the activity of PII receptors that regulate transcription from nitrogen-regulated promoters and the activity of glutamine synthetase. Here, we present a detailed analysis of the uridylyltransferase and uridylyl-removing activities and their regulation by the small molecule effectors ATP, 2-ketoglutarate, and glutamine. Several important features of enzyme mechanism and regulation were elucidated. Mg2+ appeared to be the physiologically relevant metal ion cofactor for both transferase and uridylyl-removing activities. The transferase reaction proceeded by an ordered bi-bi kinetic mechanism, with PII binding before UTP and pyrophosphate (PPi) released before PII-UMP. The uridylyl-removing reaction proceeded with rapid equilibrium binding of substrate and random release of products. Both reactions were activated by ATP and 2-ketoglutarate, which did so by binding only to PII and PII-UMP. The binding of these effectors to PII and PII-UMP was characterized. Glutamine inhibited the transferase reaction by inhibiting the chemistry step, while glutamine provided nonessential mixed-type activation of the uridylyl-removing activity, lowering the apparent Km and increasing kcat. Our data were consistent with the hypothesis that all effects of glutamine are due to the binding of central complexes at a single glutamine site. By comparing the effects of the activators with their reported in vivo concentrations, we conclude that in intact cells the uridylylation state of PII is regulated mainly by the glutamine concentration and is largely independent of the 2-ketoglutarate concentration. Our kinetic data were consistent with the hypothesis that both transferase and uridylyl-removal reactions occurred at a single active center on the enzyme.

The regulation of Escherichia coli glutamine synthetase revisited: role of 2-ketoglutarate in the regulation of glutamine synthetase adenylylation state

The regulation of Escherichia coli glutamine synthetase (GS) by reversible adenylylation has provided one of the classical paradigms for signal transduction by cyclic cascades. Yet, many mechanistic features of this regulation remain to be elucidated. We examined the regulation of GS adenylylation state in a reconstituted system containing GS, adenylyltransferase (ATase), the PII signal transduction protein that controls ATase, and the uridylyltransferase/uridylyl-removing enzyme (UTase/UR), which has a role in regulating PII. In this reconstituted bicyclic cascade system, the adenylylation state of GS was regulated reciprocally by the small molecule effectors 2-ketoglutarate and glutamine at physiological effector concentrations. By examination of the individual regulatory monocycles and comparison to the bicyclic system and existing data, we could deduce that the only sensors of 2-ketoglutarate were PII and PII-UMP. At physiological conditions, we observed that the main role of 2-ketoglutarate in bringing about the deadenylylation of GS was to inhibit GS adenylylation, and this was due to the allosteric regulation of PII activity. Glutamine acted as an allosteric regulator of both ATase and UTase/UR. We also compared the regulation of GS adenylylation state to the regulation of phosphorylation state of the transcription factor NRI (NtrC) in a reconstituted bicyclic system containing NRI, the bifunctional kinase/phosphatase NRII (NtrB), PII, and the UTase/UR. This comparison indicated that, at a fixed 2-ketoglutarate concentration, the regulation of GS adenylylation state by glutamine was sharper and occurred at a higher concentration than did the regulation of NRI phosphorylation. The possible biological implications of this regulatory arrangement are discussed.

Reconstitution of the signal-transduction bicyclic cascade responsible for the regulation of Ntr gene transcription in Escherichia coli

Nitrogen-regulation of gene transcription in Escherichia coli results from the regulation of the phosphorylation state of the enhancer-binding transcription factor NRI (NtrC). We examined the regulation of NRI phosphorylation in a reconstituted bicyclic cascade system containing four regulatory proteins: NRI, the signal-transducing uridylyltransferase/uridylyl-removing enzyme (UTase/UR), its substrate the signal transduction protein PII, and the kinase/phosphatase NRII (NtrB), which is a PII receptor that phosphorylates and dephosphorylates NRI. In this reconstituted system, the phosphorylation state of NRI was regulated reciprocally by the small molecule effectors glutamine, which prevented the accumulation of NRI-P, and 2-ketoglutarate, which caused accumulation of NRI-P. Regulation of the bicyclic system by glutamine was exclusively due to sensation and signal-transduction by the UTase/UR-PII monocycle, which was observed to function essentially as a glutamine-sensing apparatus. In contrast, regulation of NRI phosphorylation by 2-ketoglutarate, which binds to PII, was due to direct regulation of the NRII-PII interaction and the rate of NRI-P dephosphorylation. Thus, the PII protein transduces the glutamine signal to the NRII-NRI monocycle in the form of its uridylylation state and is also the receptor of the antagonistic 2-ketoglutarate signal, which blocks the activity of unmodified PII.

Endothelial cell death, angiogenesis, and microvascular function after castration in an androgen-dependent tumor: role of vascular endothelial growth factor

The sequence of events that leads to tumor vessel regression and the functional characteristics of these vessels during hormone-ablation therapy are not known. This is because of the lack of an appropriate animal model and monitoring technology. By using in vivo microscopy and in situ molecular analysis of the androgen-dependent Shionogi carcinoma grown in severe combined immunodeficient mice, we show that castration of these mice leads to tumor regression and a concomitant decrease in vascular endothelial growth factor (VEGF) expression. Androgen withdrawal is known to induce apoptosis in Shionogi tumor cells. Surprisingly, tumor endothelial cells begin to undergo apoptosis before neoplastic cells, and rarefaction of tumor vessels precedes the decrease in tumor size. The regressing vessels begin to exhibit normal phenotype, i.e., lower diameter, tortuosity, vascular permeability, and leukocyte adhesion. Two weeks after castration, a second wave of angiogenesis and tumor growth begins with a concomitant increase in VEGF expression. Because human tumors often relapse following hormone-ablation therapy, our data suggest that these patients may benefit from combined anti-VEGF therapy.

A randomized trial of the effect of ritonavir in maintaining quality of life in advanced HIV disease. Advanced HIV Disease Ritonavir Study Group

BACKGROUND

The aim of treatment for HIV disease is prolonging survival and improvement in health-related quality of life. Ritonavir is a potent, orally bioavailable HIV protease inhibitor with demonstrated impact on surrogate endpoints, AIDS-defining disease, and mortality.

OBJECTIVES

To evaluate the effect of ritonavir combined with reverse transcriptase inhibitor therapy on patient functioning and well-being.

METHODS

An international, multicenter randomized placebo-controlled clinical trial of ritonavir was conducted in HIV-infected patients with CD4 cell counts < or = 100 x 10(6)/l. A total of 1090 patients were randomized to ritonavir and continued treatment with as many as two nucleoside agents (n=543) or placebo and continued treatment with as many as two nucleoside agents (n=547). Health-related quality of life was measured at baseline and after 3 and 6 months of treatment using the Medical Outcomes Study HIV Health Survey (MOS-HIV) and HIV-related symptoms scale. MOS-HIV contains 10 subscales and two summary scores (physical health and mental health).

RESULTS

The two treatment groups were comparable on baseline CD4 cell counts, demographic characteristics, and MOS-HIV and HIV symptom subscale scores. After 3 months, statistically significant differences (P < 0.03) favoring the ritonavir-treated patients were seen on the physical health summary, mental health summary, and general health perceptions, social function, mental health, and energy/fatigue subscales. After 6 months of ritonavir therapy, significant differences were observed on physical health and mental health summary scores (P < 0.001), and on measures of general health perceptions, physical function, role function, social function, cognitive function, mental health, health distress, energy/fatigue, and overall ratings of quality of life (P < 0.01). Ritonavir-treated patients reported fewer fever symptoms and neurologic symptoms than the placebo group after 6 months of treatment (P < 0.005).

CONCLUSIONS

Ritonavir therapy, combined with other antiretroviral treatments, significantly contributes to maintenance of functioning and well-being over at least 6 months in patients with advanced HIV disease.

[Changes in distortion product otoacoustic emissions and hair cells after noise exposure in guinea pigs]

In order to observe the changes in distortion product otoacoustic emissions (DPOAE) and hair cells after noise exposure, sixteen healthy guinea pigs were used. The animals were divided into 3 groups. Group 1 was normal animals. Group 2 and 3 were animal right and 7 days after exposed to 115 dB SPL simulated submarine engine room noise for 4 hours, respectively. The DPOAE audiogram and I/O function were measured before and after exposure. The changes of hair cells were observed by light microscope and scanning electron microscope. The amplitudes of DPOAE disappeared right after noise exposure(P < 0.01) and recovered to normal at 7 days after exposure (P > 0.05). The light microscopy and scanning electron microscopy showed the stereocilia of the outer hair cells were disarrangement and some disappeared at 2,3,4 kHz regions of the cochlea. The results indicated that the normal outer cells can regulate and compensate the function of some damaged outer hair cells which result in a normal DPOAE in mild damaged cochlea.

Expression and regulation of hFIX minigene and cDNA driven by beta-casein gene in mouse mammary gland

Mammary gland specific expression vectors for human clotting factor IX (hFIX) and LacZ reporter gene driven by bovine beta-casein gene were constructed. Vectors were packaged by stearylamine (SA) liposome and were transferred to lactating mice via tail vein. Both hFIX and Lac2 gene could be expressed in the mammary gland of the treated mice. The highest production of hFIX protein was 80.28 ng per mL milk, and more than 85% of hFIX protein appeared to be gamma-carboxylation and biologically active. The results suggested that the 2.0 kb sequence of beta-casein gene including promoter, exon 1 was effective to drive hFIX gene expression in mammary gland and intron 1 of beta-casein gene had an effect on the tissue specific expression. The expression level in mouse milk injected with hFIX minigene vector containing hFIX endogenous intron 1 was increased by above 3 times of that injected with hFIX cDNA vector.

Membrane protein proteolysis assayed by fluorescence quenching: assay of O-sialoglycoprotein endopeptidase

The assay of the O-sialoglycoprotein endopeptidase of Pasteurella haemolytica has previously used the cleavage of 125I-labeled glycophorin A, measured by SDS-PAGE, autoradiography, gel-slicing, and scintillation counting. A new assay is based on the increased fluorescence which results from proteolytic cleavage of a fluorescence-quenched micellar substrate, 4,4-difluor-5,7-dimethyl-4-bora-3 alpha, 4 alpha-diaza-s-indacene-3-propionic acid conjugated to glycophorin A (BODIPY-FL-glycophorin A). Micellar association of glycophorin A molecules results in 97% fluorescence quenching despite a low molar ratio of BODIPY-FL-glycophorin A. Proteolysis of the membrane protein causes greatly enhanced fluorescence which is used for a rapid one-step proteolysis assay. Direct monitoring of proteolysis in microcuvettes, or routine assay in microtiter plates can be used. Reproducibility is higher than with the radiolabeled substrate and the K(m) values for the two substrates are similar. The assay is suitable for the O-sialoglycoprotein endopeptidase activity of chromatographically purified enzyme or unpurified bacterial culture supernatants and can be used to monitor inhibition of the O-sialoglycoprotein endopeptidase by neutralizing antibodies. The O-sialoglycoprotein endopeptidase assay employing BODIPY-FL-glycophorin A provides a rapid and nonradioactive method for the assay of this highly specific enzyme.

[Applied anatomy of the temporal and frontal regions in endoscopic temporal lifting]

OBJECTIVE

This anatomic study was carried out in a bid to decrease damage of the temporal branch of the face nerve in endoscopic temporal lifting.

METHODS

We dissected the frontal-temporal region and located the temporal branch on 36 sides of adult head specimens.

RESULTS

It was found that the temporal branch is deep to the temporoparietal fascia and frontal muscle. The temporal branch has one to four branches in general. The first one is 8.1 +/- 2.1 mm anterior to articular tubercle and 33.8 +/- 4.9 mm superior to the bony lateral canthus. The temporal branches locate below a line drawn from the articular tubercle to 40 mm above the bony lateral canthus.

CONCLUSION

It is suggested that the operation incisions in the temporal region be selected above this line.

Inner ear damage in guinea pigs exposed to stable and impulse noise

OBJECTIVE

To investigate the inner ear damage after exposure to stable noise, impulse noise and stable plus impulse noise in guinea pigs.

METHODS

Ninety-six healthy guinea pigs were divided into 3 equal groups. (1) Stable noise group: exposed to 110 dBA stable noise for 3 days, 4 hours per day. (2) Impulse noise group: exposed to 165 dBA simulated cannon fire impulse noise 10 times successively at an interval of 10 seconds. (3) stable plus impulse noise group: exposed to the same stable noise as that in the first group, then after a 2-hour rest, the animals were followed with impulse noise exposures as that in the second group. After those exposure, each of the 3 groups was further divided into 4 subgroups according to the time after the noise exposure, namely, the right after, 7 d, 14 d and 30 d groups. The evoked cortical potential responses to click and tone burst stimulation sound were examined. The surface preparation and celloidine embedded serial section of the cochlea were observed under a light microscope.

RESULTS

Both the stable and impulse noise could increase the hearing threshold and damage the inner ear hair cells. The damage in the first group was relatively slight, whereas in group 3 the damage was more severe than that in the other 2 groups.

CONCLUSION

For seamen who are working in heavy noise environment, corresponding measures should be taken to protect their ears from noise which induces hearing loss.

Diffusion, perfusion, and T2 magnetic resonance imaging of anti-intercellular adhesion molecule 1 antibody treatment of transient middle cerebral artery occlusion in rat

The effect of anti-intercellular adhesion molecule-1 (anti-ICAM-1) antibody treatment of transient (2 h) middle cerebral artery (MCA) occlusion in the rat was measured using diffusion (DWI)-, T2 (T2I)- and perfusion (PWI)-weighted magnetic resonance imaging. Rats were treated upon reperfusion with an anti-ICAM-1 monoclonal antibody (n=11) or a control antibody (n=7). DWI, T2I and PWI were performed before, during, and after induction of focal cerebral ischemia from 1 h to 7 days. In both groups, the apparent diffusion coefficient of water (ADCw) and cerebral blood flow (CBF) values in the ischemic region significantly declined from the preischemic ADCw values (p<0. 05). The post ischemic increase in T2 of the control group was significantly higher at 48 h than in the anti-ICAM-1 treated group (p<0.05). CBF was not significantly different between the two groups. The temporal profiles of MRI cluster analysis, which combines ADCw and T2 maps into a single image, was significantly different between groups. These data suggest that the neuroprotective effect of anti-ICAM-1 antibody treatment is reflected in reductions of T2 and lesion growth during reperfusion and may not be associated with increased cerebral perfusion.

Mutant human presenilin 1 protects presenilin 1 null mouse against embryonic lethality and elevates Abeta1-42/43 expression

Mutations in presenilin 1 (PS1) are linked to early onset of familial Alzheimer's disease (FAD) and are shown to foster production of Abeta1-42/43 in FAD patients and transgenic mice. PS1 null mice are embryonic lethal and exhibit axial skeleton malformation and CNS defects. We show that transgenic mouse lines expressing either the wild-type human PS1 protein or human PS1 with the A246E FAD mutation can rescue the PS1 knockout mouse from embryonic lethality to similar degrees, indicating that the mutation does not lead to loss of PS1 function during development. Furthermore, a 50% reduction of PS1 activity in PS1(+/-) mice does not lead to Abeta1-42/43 increase, whereas expression of human mutant PS1 on murine PS1 null background is sufficient to elevate Abeta1-42/43, supporting a gain-of-function activity as the result of the PS1 mutation.

Structure/function analysis of the PII signal transduction protein of Escherichia coli: genetic separation of interactions with protein receptors

The PII protein, encoded by glnB, is known to interact with three bifunctional signal transducing enzymes (uridylyltransferase/uridylyl-removing enzyme, adenylyltransferase, and the kinase/phosphatase nitrogen regulator II [NRII or NtrB]) and three small-molecule effectors, glutamate, 2-ketoglutarate, and ATP. We constructed 15 conservative alterations of PII by site-specific mutagenesis of glnB and also isolated three random glnB mutants affecting nitrogen regulation. The abilities of the 18 altered PII proteins to interact with the PII receptors and the small-molecule effectors 2-ketoglutarate and ATP were examined by using purified components. Results with certain mutants suggested that the specificity for the various protein receptors was altered; other mutations affected the interaction with all three receptors and the small-molecule effectors to various extents. The apex of the large solvent-exposed T loop of the PII protein (P. D. Carr, E. Cheah, P. M. Suffolk, S. G. Vasudevan, N. E. Dixon, and D. L. Ollis, Acta Crytallogr. Sect. D 52:93-104, 1996), which includes the site of PII modification, was not required for the binding of small-molecule effectors but was necessary for the interaction with all three receptors. Mutations altering residues of this loop or affecting the nearby B loop of PII, which line a cleft between monomers in the trimeric PII, affected the interactions with protein receptors and the binding of small-molecule ligands. Thus, our results support the predictions made from structural studies that the exposed loops of PII and cleft formed at their interface are the sites of regulatory interactions.

Probing interactions of the homotrimeric PII signal transduction protein with its receptors by use of PII heterotrimers formed in vitro from wild-type and mutant subunits

The homotrimeric PII signal transduction protein of Escherichia coli interacts with two small-molecule effectors, 2-ketoglutarate and ATP, regulates two protein receptors, the kinase/phosphatase nitrogen regulator II (NRII) and the glutamine synthetase (GS) adenylyltransferase (ATase), and is subject to reversible uridylylation, catalyzed by the uridylyltransferase/uridylyl-removing enzyme (UTase/UR). The site of PII uridylylation, Y51, is located at the apex of the solvent-exposed T-loop (E. Cheah, P. D. Carr, P. M. Suffolk, S. G. Vasudevan, N. E. Dixon, and D. L. Ollis, Structure 2:981-990, 1994), and an internally truncated PII lacking residues 47 to 53 formed trimers that bound the small-molecule effectors but were unable to be uridylylated or activate NRII and ATase (P. Jiang, P. Zucker, M. R. Atkinson, E. S. Kamberov, W. Tirasophon, P. Chandran, B. R. Schefke, and A. J. Ninfa, J. Bacteriol. 179:4342-4353, 1997). We investigated the ability of heterotrimers containing delta47-53 and wild-type subunits to become uridylylated and activate NRII and ATase. Heterotrimers were formed by denaturation and renaturation of protein mixtures; when such mixtures contained a fivefold excess of A47-53 subunits, the wild-type subunits were mostly redistributed into trimers containing one wild-type subunit and two mutant subunits. The resulting population of trimers was uridylylated and deuridylylated by UTase/UR, stimulated the phosphatase activity of NRII, and stimulated adenylylation of GS by ATase. In all except the ATase interaction, the activity of the hybrid trimers was greater than expected based on the number of wild-type subunits present. These results indicate that a single T-loop region within a trimer is sufficient for the productive interaction of PII with its protein receptors. We also formed heterotrimers containing wild-type subunits and subunits containing the G89A alteration (P. Jiang, P. Zucker, M. R. Atkinson, E. S. Kamberov, W. Tirasophon, P. Chandran, B. R. Schefke, and A. J. Ninfa, J. Bacteriol. 179: 4342-4353, 1997). The G89A mutant form of PII does not bind the small-molecule effectors, does not interact with UTase or with NRII, and interacts poorly with ATase. Heterotrimers formed with a 10/1 starting ratio of G89A to wild-type subunits interacted with UTase/UR and ATase to a lesser extent than expected based on the number of wild-type subunits present but activated NRII slightly better than expected based on the number of wild-type subunits present. Thus, intersubunit interactions within the PII trimer can adversely affect the activity of wild-type subunits and may affect the interactions with the different receptors in a variable way. Finally, we formed heterotrimers containing delta47-53 and G89A mutant subunits. These heterotrimers were not uridylylated, did not interact with NRII, and interacted with the ATase only to the extent expected based on the number of G89A subunits present. Thus, the G89A subunits, which contain an intact T-loop region, were not "repaired" by inclusion in heterotrimers along with delta47-53 subunits.

[Effect of perilymphatic fistula on distortion product otoacoustic emissions in guinea pigs]

Perilymphatic fistula was induced in 11 healthy guinea pigs to study its effects on distortion product otoacoustic emissions (DPOAEs). DPOAE amplitudes decreased significantly right after formation of the fistula (P < 0.01), and recurred to near pretreatment level in animals whose fistula healed. The amplitude remained below pretreatment level 18 days after fistulization in those animals whose fistula failed to heal. Under light microscope, the organ of Corti was seen normal. The authors feel that DPOAEs may be helpful in detecting perilymphatic fistula.

Risk of tongue cancer associated with tobacco smoking and alcohol consumption: a case-control study

Recent studies indicate that cancer of the tongue is increasing rapidly among the younger population in many parts of the world. Few studies, however, have directly examined the risk factors for the disease. A case-control study was conducted in Beijing, China to investigate risk factors for tongue cancer. A total of 111 cases and 111 controls aged 20-80 years were included in this study. The results show that risk of tongue cancer is significantly elevated among ex-smokers (OR = 2.24, 95% CI = 1.09-4.62) and among current smokers (OR = 2.73, 95% CI = 1.26-5.91). The risk increases with increasing tobacco consumption, as reflected by both cigarette equivalents smoked per day and lifetime pack-years of tobacco smoking. Quitting smoking was associated with a reduction of the risk of tongue cancer. The numbers of cases in the study, however, is small, preventing further analyses during the years after quitting smoking. Overall, alcohol drinking was not found to be significantly associated with the risk of tongue cancer in this study (OR = 1.20, 95% CI = 0.58-2.50 for current drinkers). However, a marginally significant association was found for those who drank spirits at least 5 days a week (OR = 2.34, 95% CI = 0.90-6.06). A suggestion of effect modification for smoking and alcohol drinking was observed in this study.

[The effect of far infrared rays on the survival of randomized skin flap in the rat: an experimental study]

In order to observe the effect of far infrared rays on the survival of skin flap, the following experiment was performed. Forty-eight SD rats were selected and divided into two groups. The rats received 0.3 w/cm2 radiation twice a day from 3 days before operation to 5 days after operation in the experimental group, while in the control group the rats received none before or after the operation. The flap was designed as 2 cm x 6 cm in the back of the rats with the pedicle caudalward. The microcirculatory changes of the flap were observed, and the survival area of the flap was calculated. The results showed that either in the proximal or in the distal part of the graft, in the experimental group, the mean opening rate, diameter and the flowing velocity of the microvessels were significantly higher than those in the control group (P < 0. 05). The mean rate of survival area of the experimental group (80.5%) was also higher than that of the control group (62.7%) (P < 0.01). It was suggested that radiation with far infrared rays could dilate the microvessels, improve the flap microcirculation, therefore, enhance the survival of the randomized skin flap.

Transcriptional activation of the human epidermal growth factor receptor promoter by human p53

The human epidermal growth factor receptor (EGFR) promoter is activated by both wild-type and tumor-derived mutant p53. In this communication, we demonstrate that EGFR promoter sequence requirements for transactivation by wild-type and mutant p53 are different. Transient-expression assays with EGFR promoter deletions identified a wild-type human p53 response element, 5'-AGCTAGACGTCCGGGCAGCCCCCGGCG -3', from positions --265 to --239. Electrophoretic mobility shift analysis and DNase I footprinting assays indicated that wild-type p53 binds sequence specifically to the response element. Using circularly permuted DNA fragments containing the p53-binding site, we show that wild-type p53 binding induces DNA bending at this site. We further show that the EGFR promoter is also activated by tumor-derived p53 mutants p53-143A, p53-175H, p53-248W, p53-273H, and p53-281G. However, the transactivation by mutant p53 does not require the wild-type p53-binding site. The minimal EGFR promoter from positions --104 to --20 which does not contain the wild-type p53-binding site is transactivated by the p53 mutants but not by the wild-type protein, showing a difference in the mechanism of transactivation by wild-type and mutant p53. Transactivation of the EGFR promoter by p53 may represent a novel mechanism of cell growth regulation.

Identification of a novel hypothalamic neuropeptide Y receptor associated with feeding behavior

Neuropeptide Y (NPY) plays important roles in the central control of appetite and energy balance, but the receptor subtype responsible for this function has not been cloned. Here we report the cloning by expression of a novel NPY receptor subtype from a rat hypothalamus cDNA library. The novel receptor, referred to as the NPY Y5 receptor, has a transcript of approximately 2.6 kilobases with an open reading frame of 1335 base pairs that encodes a 445-amino acid protein. The amino acid sequence deduced from the rat Y5 cDNA clone shows only 30-33% identity to other NPY receptors, including Y1, Y2, and Y4/PP1. Using the rat Y5 receptor cDNA probe, the human homologue was obtained by low stringency hybridization. The human Y5 amino acid sequence has 88% identity to the rat Y5 receptor. Importantly, pharmacological analysis shows that the rat and human Y5 receptors have high affinity for the peptides that elicit feeding (e.g. NPY, PYY, (2-36)NPY, and (LP)NPY) and low affinity for nonstimulating peptides (e.g. (13-36)NPY and rat PP), suggesting that it is the NPY feeding receptor subtype.

Generation of an integrated transcription map of the BRCA2 region on chromosome 13q12-q13

An integrated approach involving physical mapping, identification of transcribed sequences, and computational analysis of genomic sequence was used to generate a detailed transcription map of the 1. 0-Mb region containing the breast cancer susceptibility locus BRCA2 on chromosome 13q12-q13. This region is included in the genetic interval bounded by D13S1444 and D13S310. Retrieved sequences from exon amplification or hybrid selection procedures were grouped into physical intervals and subsequently grouped into transcription units by clone overlap. Overlap was established by direct hybridization, cDNA library screening, PCR cDNA linking (island hopping), and/or sequence alignment. Extensive genomic sequencing was performed in an effort to understand transcription unit organization. In total, approximately 500 kb of genomic sequence was completed. The transcription units were further characterized by hybridization to RNA from a series of human tissues. Evidence for seven genes, two putative pseudogenes, and nine additional putative transcription units was obtained. One of the transcription units was recently identified as BRCA2 but all others are novel genes of unknown function as only limited alignment to sequences in public databases was observed. One large gene with a transcript size of 10.7 kb showed significant similarity to a gene predicted by the Caenorhabditis elegans genome and the Saccharomyces cerevisiae genome sequencing efforts, while another contained a motif sequence similar to the human 2',3' cyclic nucleotide 3' phosphodiesterase gene. Several retrieved transcribed sequences were not aligned into transcription units because no corresponding cDNAs were obtained when screening libraries or because of a lack of definitive evidence for splicing signals or putative coding sequence based on computational analysis. However, the presence of additional genes in the BRCA2 interval is suggested as groups of putative exons and hybrid selected clones that were transcribed in consistent orientations could be localized to common physical intervals.

[Flavanonol glucosides of Smilax glabra Roxb]

Three flavanonol glucosides have been isolated from the rhizome of Smilax glabra. Their structures were identified as isoengetitin, isoastilbin and astilbin on the basis of their physicochemical and spectral data. Full as signment of their 1HNMR and 13CNMR chemical shift signals was established by various 2D-NMR techniques. Their glucosidic bond structures were determined for the first time. Isoastilbin was isolated from Smilax for the first time.

The complete BRCA2 gene and mutations in chromosome 13q-linked kindreds

Breast carcinoma is the most common malignancy among women in developed countries. Because family history remains the strongest single predictor of breast cancer risk, attention has focused on the role of highly penetrant, dominantly inherited genes in cancer-prone kindreds (1). BRCA1 was localized to chromosome 17 through analysis of a set of high-risk kindreds (2), and then identified four years later by a positional cloning strategy (3). BRCA2 was mapped to chromosomal 13q at about the same time (4). Just fifteen months later, Wooster et al. (5) reported a partial BRCA2 sequence and six mutations predicted to cause truncation of the BRCA2 protein. While these findings provide strong evidence that the identified gene corresponds to BRCA2, only two thirds of the coding sequence and 8 out of 27 exons were isolated and screened; consequently, several questions remained unanswered regarding the nature of BRCA2 and the frequency of mutations in 13q-linked families. We have now determined the complete coding sequence and exonic structure of BRCA2 (GenBank accession #U43746), and examined its pattern of expression. Here, we provide sequences for a set of PCR primers sufficient to screen the entire coding sequence of BRCA2 using genomic DNA. We also report a mutational analysis of BRCA2 in families selected on the basis of linkage analysis and/or the presence of one or more cases of male breast cancer. Together with the specific mutations described previously, our data provide preliminary insight into the BRCA2 mutation profile.

[A primary study on treatment of intracranial hematomas with specially designed needle puncture]

We treat hematomas by special designed needles and other techniques for breaking and liquefying hematoma. This method is easy to learn and needn't operation room, even can be done at the patient's bedside. Its merits the included point wound without craniotomy, low medical cost and satisfactory result. We treat 112 patients with hypertensive intracranial hematomas, 25 patients with acute epidural hamatoma and 17 patients with hematoma due to other causes. In the total of 154 patients, 20 had brain herniations and 104 coma. The mortality was very low (8.44%). 94 patients (91.34%) woke up in 1 to 2 weeks.

Comparative analysis of Homo sapiens and Mus musculus cyclin-dependent kinase (CDK) inhibitor genes p16 (MTS1) and p15 (MTS2)

Cyclin-dependent kinase inhibitors are a growing family of molecules that regulate important transitions in the cell cycle. At least one of these molecules, p16, has been implicated in human tumorigenesis while its close homolog, p15, is induced by cell contact and transforming growth factor-beta (TGF-beta). To investigate the evolutionary and functional features of p15 and p16, we have isolated mouse (Mus musculus) homologs of each gene. Comparative analysis of these sequences provides evidence that the genes have similar functions in mouse and human. In addition, the comparison suggests that a gene conversion event is part of the evolution of the human p15 and p16 genes.