Mapping of chromosomal gains and losses in prostate cancer by comparative genomic hybridization

Comparative genomic hybridization (CGH) allows detection of chromosomal imbalances in whole genomes in a comprehensive manner. With this approach, ten cases of prostate cancer (seven primary tumors and three metastases) were analyzed. Frequent chromosomal gains detected by CGH involved chromosome arms 7q, 8q, 9q, and 16p, and chromosomes 20 and 22, as well as frequent losses of chromosome arms 16q and 18q, in at least three of the ten cases. Overrepresentation of chromosome arm 9q has not been described in published reports. The CGH data were compared with results of a loss of heterozygosity (LOH) study, in which complete allelotyping was performed in the same prostate tumors with 74 different polymorphic markers. In general, a high concordance between the CGH and LOH results was observed (92%). Tumors revealing discrepancies by CGH and LOH analysis were investigated further by interphase cytogenetics, and the resulting picture regarding the genomic alterations is discussed in detail.

31P-19F rotational-echo, double-resonance nuclear magnetic resonance experiment on fluoridated hydroxyapatite

This work demonstrates 31P-19F rotational-echo, double-resonance nuclear magnetic resonance (REDOR NMR), a simple experiment used to measure 31P-19F dipolar couplings. 19F-observed 31P-19F REDOR NMR of fluorapatite revealed the 31P-19F connectivities. 31P-observed 31P-19F REDOR NMR determined the nearest 31P-19F distance in fluorapatite. The application on fluoride-treated hydroxyapatite, the principal inorganic constituent of dental enamel and dentine, showed the formation of fluorohydroxyapatite with a surface coverage of less than one unit-cell layer.

Expression of serum albumin and of alphafetoprotein in murine normal and neoplastic primitive embryonic structures

Alphafetoprotein (AFP), a major serum protein synthesized during the embryo-fetal and postnatal period (in the yolk sac, then in the liver), is also an oncoprotein. The intracellular presence of AFP and of serum albumin (SA) in normal and neoplastic neural crest and neural tube derivatives was previously demonstrated. In this work we have studied the comparative expression of AFP and SA in primitive neuroectoblastic structures of mouse embryos (6 and 7 days "post coitum") and mouse teratocarcinomas (derived from the PCC4 cell line). Using immunofluorescence technique, antibodies to SA gave a positive reaction in embryos of 7 days, while AFP was not detected during this period. By mRNA in situ hybridization, SA mRNA gave a strong signal in both 6 and 7 day embryos, whereas AFP mRNA gave a weak signal only in 7-day embryos. The distribution of SA and AFP and their mRNAs was investigated in primitive neuroectoblastic structures of the teratocarcinomas by in situ hybridization and immunostaining. Only SA protein was detectable by immunostaining. SA mRNA gave a strong signal in differentiating structures as well as in undifferentiated cell clusters. AFP mRNA was observed only in differentiating structure. Dot-blot hybridization indicated that the level of SA transcripts was at least 6-fold higher than that of AFP transcripts in the teratocarcinomas investigated. In teratocarcinoma-bearing mice injected intraperitoneally with 125I-radiolabeled SA and AFP, significant accumulations of both SA and AFP were demonstrated in the tumors, SA being about 3-fold higher than that of AFP after normalization to quantity of uptake in liver. External in vivo photoscanning confirmed this relationship of accumulated radiolabeled proteins. The last observation could be useful in vivo for diagnosis of teratocarcinoma. We conclude that the expression of SA relative to AFP and the external cellular uptake of SA relative to AFP are similar in normal embryonic developing tissues and in the corresponding morphologically neoplastic tissues of the teratocarcinomas. The same SA:AFP relationship constitutes an oncofetal marker of primitive neuroectoblastic structures.

Low-coherence optical tomography in turbid tissue: theoretical analysis

On the basis of white-light interferometry and statistical optics, a theoretical model for low-coherence optical tomography is presented that establishes the relation of interference modulation with path-length-resolved reflectance and that can provide analytical expressions and numerical solutions by means of a Fourier transform. The Monte Carlo technique is used to simulate the path-length-resolved reflectance from different multilayer tissue phantoms. Theoretical analyses and preliminary experimental results suggest that, unlike time-resolved spectroscopy, low-coherence optical tomography detects the local relative variations of path-length-resolved reflectance from the turbid tissues.

[Influence of fluoride varnish of different concentration on microhardness of enamel surface]

Varnish is a new type oral material which develops rapidly in recently years,It have had extensive study abroad.It is one of the topical application of fluoride,among them,fluoride-sodium varnish have more significant effect on prevention of dental caries.This study observed the changes of microhardness of cramels after applying fluorid-sodium varnish of different concentration to enamel surfaces.Enamels were randomly parted into three groups,A.B and C.Before fluoride application,the microhardness of enamels were detected,and no significant difference were found among three groups,After that,0.5%,1.5%,2.7% fluoride-sodium varnish were daubed respectively on the three groups enamel surfaces for 24h.The microhardness of enamels were detected again.The results showed all the microhardness of enamels have significant increase statistically after applying fluoride-sodium varnish of different concentration.But,for 0.5% fluorid-Sodium varnish,the increase of microhardness of enamels was only one half of the other two group,which suggested in some concentration range,the fluoride concentration increased one time,the microhardness of enamels increased about one time, but the increase of microhardness of enamels was not synchronized with the increase of fluoride concentration.The increase of microhardness of enamels is almost the same between the two high concentration fluoride-sodium varnish groups,and there in no significant difference statistically.That is when some fluoride concentration were reached,the microhardness of enamels won't increase any more.By the experiment,the writer suggests 1.5% fluorid-sodium varnish is the best on prevention of dental caries.

Proposed structure of the A domains of factor VIII by homology modelling

We have predicted a structure for the three A domains of blood coagulation factor VIII by virtue of their homology to blue copper-binding proteins. This structure, consisting of six beta-barrels, is arranged in a triangular configuration with a single type II copper-binding site linking the A1 and A3 domains.

Quantitative and dynamic MRI of neuroprotection in experimental stroke

Experimental studies of stroke in animal models have traditionally relied on histological endpoints for the measurement of neuroprotection. In this study, we used in vivo and dynamic MRI to quantify the neuroprotective effects of the non-competitive NMDA antagonist MK801. Four hours of occlusion followed by 6 h of reperfusion was performed in a rabbit model of focal cerebral ischemia. Spin-echo T2-weighted (T2W) MRI was used to quantify ischemic lesion volumes. Hemispheric measurements of perfusion deficits were assessed by using dynamic susceptibility-contrast MRI to map the first-pass transit of injected GdDTPA. Histological correlates of infarction were quantified using tetrazolium staining. Animals treated with 2 mg/kg MK801 infused immediately post-occlusion (n = 6) were compared with untreated controls (n = 8). T2W MRI scans obtained after 6 h of reperfusion showed high-intensity lesions in the ischemic basal ganglia and cortex. MK801-treated animals showed significantly decreased lesion volumes compared to untreated controls (7.3 +/- 3.2% treated vs 20.7 +/- 4.8% control, p < 0.05). Lesion volumes measured with MRI were significantly correlated with tetrazolium-defined infarct volumes (r = 0.766, p = 0.004). Dynamic MRI demonstrated the phenomenon of delayed hypoperfusion in the ischemic hemisphere during the late reperfusion phase; relative cerebral blood volume (rCBV) was 45.2 +/- 10.3% in untreated animals. MK801 slightly improved these deficits although the differences did not reach statistical significance (rCBV = 77.0 +/- 9.7%, p = 0.128).(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous transluminal gene transfer into canine myocardium in vivo by replication-defective adenovirus

OBJECTIVE

The aim was to examine the feasibility, efficiency and safety of adenovirus-mediated in vivo gene transfer into the canine myocardium by a percutaneous transluminal method using a needle-catheter.

METHODS

Either a replication-defective adenovirus (Adex1SRLacZL) or a plasmid (pSRLacZ), both expressing E. coli lacZ coding beta-galactosidase (beta-gal), was directly injected into the left ventricle of dogs through a needle-catheter inserted via a femoral artery. Expression of lacZ was examined by histochemical staining and quantified by measuring beta-gal activity.

RESULTS

Injections with Adex1SRLacZL induced lacZ expression as a result of 40 out of 41 injections; the expression level was 10 times higher than that obtained with pSRLacZ. Induced beta-gal activity was detected within 24 h, peaked at 7 days and retained for 2 weeks after gene transfer. A repetitive administration of the same adenovirus at 14 days after the first injection also evoked a reduced but significant level of expression despite neutralizing antibodies to adenovirus in serum. Although injection induced an inflammatory response that peaked at 3 days after injection and gradually subsided without a second peak, the temporal change and the extent of inflammation induced by adenovirus injection was not significantly different from those induced by injection with either saline or plasmid. Neither leakage of enzymes such as CPK or LDH nor alteration in the ECG was detected in the 30 days following gene transfer.

CONCLUSIONS

Our findings demonstrate that a catheter-mediated direct injection with an adenovirus can induce gene expression in the ventricle more efficiently without additional myocardial damage and inflammation compared with injection with a plasmid. A repeat dose of the same adenovirus elicited gene expression at an attenuated but significant level. This method may potentially have clinical applications: in modifying myocardial phenotype and/or improving general circulation under certain circumstances.

[Analysis of 29 maternal deaths caused by amniotic fluid embolism]

Twenty nine maternal deaths caused by amniotic fluid embolism (AFE) during 1989-1993 in Beijing area were reviewed. The results show that the average maternal mortality ratio due to AFE was 5.9/100,000 live births responsible for 15.5% of total maternal deaths. In 13 of the 29 patients presented the clinical signs were of postpartum hemorrhage and coagulation disorders. Oxytocics had been used in 12 of the 29 cases during labor. In more than half of the patients there was delay in diagnosis. This was that the percentage of AFE which may present with the signs of coagulation disorder was higher than previously thought, and unreasonable use of oxytocics during labor may be associated with AFE. This kind of AFE is easy to misdiagnose.

Hepatitis C virus type I(1a) in northern China

Twenty-four patients with hepatitis C virus (HCV) antibody from the Chinese North Western province of Jilin were further analysed by the immunoblot assay-2 (RIBA-2), reverse transcription-polymerase chain reaction (RT-PCR) for serum HCV RNA detection, and direct sequence-genotyping. Good concordance was found between the original second generation HCV antibody ELISA, RIBA-2, and serum HCV RNA. The occurrence of genotype I (1a), a genotype not previously reported in China, is described in 5(20.8%) of 24 cases, in association with genotypes II(1b) and III(2a) which were found in 16(66.7%) and 3(12.5%) of 24 cases, respectively. Imported blood products were unlikely to be the source of infection with genotype I (1a) but could not be definitively ruled out.

The minor form alpha' chain from lamprey fibrinogen is rapidly crosslinked during clotting

Lampreys have two genes for the alpha chains of fibrinogen, the second of which encodes a minor form with a carboxyl-terminal domain homologous to the carboxyl-terminal domains of beta and gamma chains. Initially, we referred to the alternative chain as alpha-II; we now use the designation alpha' in order to facilitate reference to crosslinked dimers. Antisera raised to synthetic peptides based on the cDNA sequence confirmed that the alpha' chain was present in fibrinogen prepared directly from plasma. The same antibodies were used to determine the size and properties of the carboxyl-terminal domain after its release by mild tryptic digestion, a fragment of apparent molecular weight 35,000-40,000 being produced. Unlike fragment D generated in the same digestions, the alpha' fragment did not bind to Gly-Pro-Arg or Gly-Val-Arg peptide affinity columns. During clotting under conditions where factor XIII is active, the alpha' chains became crosslinked very much more rapidly than ordinary alpha chains, the principal product being an apparent dimer, but smaller amounts of higher multimers being detectable. The crosslinking was inhibited by various amines, as well as by peptides that prevent polymerization.

Properties of Rab5 N-terminal domain dictate prenylation of C-terminal cysteines

Rab5 is a Ras-related GTP-binding protein that is post-translationally modified by prenylation. We report here that an N-terminal domain contained within the first 22 amino acids of Rab5 is critical for efficient geranylgeranylation of the protein's C-terminal cysteines. This domain is immediately upstream from the "phosphate binding loop" common to all GTP-binding proteins and contains a highly conserved sequence recognized among members of the Rab family, referred to here as the YXYLFK motif. A truncation mutant that lacks this domain (Rab5(23-215) fails to become prenylated. However, a chimeric peptide with the conserved motif replacing cognate Rab5 sequence (MAYDYLFKRab5(23-215) does become post-translationally modified, demonstrating that the presence of this simple six amino acid N-terminal element enables prenylation at Rab5's C-terminus. H-Ras/Rab5 chimeras that include the conserved YXYLFK motif at the N-terminus do not become prenylated, indicating that, while this element may be necessary for prenylation of Rab proteins, it alone is not sufficient to confer properties to a heterologous protein to enable substrate recognition by the Rab geranylgeranyl transferase. Deletion analysis and studies of point mutants further reveal that the lysine residue of the YXYLFK motif is an absolute requirement to enable geranylgeranylation of Rab proteins. Functional studies support the idea that this domain is not required for guanine nucleotide binding since prenylation-defective mutants still bind GDP and are protected from protease digestion in the presence of GTP gamma S. We conclude that the mechanism of Rab geranylgeranylation involves key elements of the protein's tertiary structure including a conserved N-terminal amino acid motif (YXYLFK) that incorporates a critical lysine residue.

[Study on animal conservation-selection index]

The concept of "conservation-selection index" was put forward based on the idea of Systematic Conservation that the conservation and selection must be combined in practice. Its calculation formula was also derived, which suits to various data and various aims of conservation and selection.

Transcription patterns of sequences on human chromosome 21

The polymerase chain reaction (PCR) was used to screen embryonic, fetal and adult human cDNA libraries for transcription on chromosome 21q22.1-->q22.3. Seventy-three pairs of oligonucleotide primers on chromosome 21, used previously to screen a fetal brain cDNA library, were applied to analyze 41 different cDNA libraries. Only phage eluate (and therefore no DNA isolation) was required for this sensitive screening. Sixty primer pairs were positive with at least one cDNA library, indicating that the majority of primers were derived from transcribed sequences. Even with our most complex human fetal brain cDNA library, we detected only 57% (34/60) of transcribed sequences, illustrating the need to screen multiple human cDNA libraries to determine if transcription occurred. Since only 3/73 clones were present in only one cDNA library, the vast majority of transcribed sequences are present in more than one tissue.

[The change of platelet number in patient with acute myocardial infarction and its clinical significance]

Platelet number and alpha-granule membrane protein (GMP-140) level on platelet surface were determined in 20 patients with acute myocardial infarction (AMI) and 20 normal subjects. The results showed that platelet number decreased significantly after AMI, especially on the second day after onset and that the level of GMP-140 increased rapidly after AMI and reached a peak on the second after the attack. Both returned to the normal on the 5-7th day after the heart attack. Correlative analysis between increase of serum CK-MB and platelet number was negative (r = -0.6123, P < 0.005), and positive between that and GMP-140 level (r = 0.5895, P < 0.01). Platelet number decreased markedly in cases with heart failure and cardiac death. The results indicate that platelets are involved in the pathological process of AMI.

Anti-idiotypic antibodies: biological function and structural studies

Under a variety of circumstances antibodies can be elicited against the variable region of other antibody molecules (anti-idotypic antibodies, anti-ids). Some of the antibodies are directed against the binding sites of the eliciting antibodies. Of particular interest are the antibodies that recognize epitopes of the original antibody that are in contact with antigen. Antibodies of this kind have been produced and used in a variety of situations including attempts at using them as therapeutic agents. In recent years structural data at the atomic level have emerged for anti-idiotypic antibodies from X-ray diffraction studies. These studies provided structural basis for molecular mimicry of anti-ids. For a large globular antigen (lysozyme), where epitope is noncontinuguous, molecular mimicry is not present at the atomic level. In this case, idiotopes are largely composed of CDR residues, but framework residues are also used. For an epitope that is sequence-specific (anti-FIPV system), molecular mimicry appears to be present as evidenced by the sequence homology between the CDR loops of the anti-id and the epitope of the original antigen. In the case of a small hormone antigen (angiotensin II), an internal image of the eliciting antigen appears to be represented in a single CDR loop of the antiiodiotypic antibody.

The effect of eight V2 vasopressin receptor mutations on stimulation of adenylyl cyclase and binding to vasopressin

We previously identified six V2 vasopressin receptor mutations in five unrelated nephrogenic diabetes insipidus (NDI) families. In order to elucidate the effect of these mutations on the function of the V2 vasopressin receptor, we introduced these six and two additional, naturally occurring mutations into the V2 vasopressin receptor gene by in vitro mutagenesis. Five of the mutants (two frameshift, one nonsense, and two missense) failed to stimulate adenylyl cyclase due to their inability to bind vasopressin under the experimental conditions. In contrast, ligand binding and cAMP accumulation were normal for two other mutations, a A61V missense mutation and an in-frame deletion of four amino acids (Arg-247 to Gly-250), suggesting that they are not the cause of NDI in these families. The deletion mutation was found in a family in conjunction with a second mutation, R181C, which yielded a much reduced ligand-binding capacity. The KD of R181C was at least 26 times higher than that of the wild type. Further characterization by an immunofluorescent assay showed that the R181C mutant receptor is expressed and distributed on the cell surface in a manner similar to that of the wild type. This finding indicates that the inability of this mutant to stimulate adenylyl cyclase is caused by the reduced capacity for vasopressin binding and that the R181C mutation is responsible for NDI in this family.

p53 deletion as a genetic marker in urothelial tumor by fluorescence in situ hybridization

In order to investigate the significance of p53 deletion, 42 specimens of transitional cell carcinoma were analyzed by interphase cytogenetics with a fluorescence in situ hybridization technique and compared with clinicopathological and cytochemical parameters. In total, 27 (64%) and 16 (38%) specimens demonstrated p53 deletion and overexpression, respectively. The p53 deletion was significantly correlated with grade (P < 0.01), stage (P < 0.05), S-phase fraction (P < 0.05), and DNA ploidy (P < 0.01), while p53 overexpression correlated only with grade (P < 0.05). The close correlation of p53 deletion with clinicopathological parameters suggests p53 deletion to be of clinical importance to indicate the malignant potential of human urothelial tumors.

Nonrandom numerical aberrations of chromosomes 7, 9, and 10 in DNA-diploid bladder cancer

Double-target in situ hybridization technique (ISH) was applied to 37 cases of bladder cancer to detect numerical aberrations of chromosomes 7, 9, 10, and 11 by centromeric DNA probes. Of 33 evaluable cases, 29 (88%) demonstrated chromosome aberrations. In 17 cases with diploid pattern as measured by flow-cytometric DNA analysis (FCM), 15 (88%) demonstrated chromosome aberrations. Of these, trisomy 7, monosomy 9, and trisomy 10 were detected in three, three, and one case, respectively, as a single chromosome aberration. In 14 (88%) of 16 cases with an aneuploid DNA pattern, chromosome aberrations for two or more chromosomes were demonstrated. A significant correlation was observed between grade of chromosome aberrations and tumor grade (p < 0.01, Fisher's test), between number of spots for chromosome 7 and peak value in FCM (p = 0.015, by Spearman rank order test). In eight cases, chromosome aberrations in the tumor were compared with the corresponding pattern in the grossly normal and histologically benign mucosa. Trisomy 10 and monosomy 9 were detected as chromosome numerical aberrations in the histologically normal mucosa, consistent with aberrations in the corresponding patients. We conclude that trisomy 7, monosomy 9, and trisomy 10 may be early events in the evolution of bladder cancer.

The effects of naloxone on the post-asphyxic cerebral pathophysiology of newborn lambs

Both early post-ischaemic blood-brain barrier disruption and enhanced brain endogenous opioid system activity have been implicated in the pathogeneses of ischaemic neuronal damage; however, their roles in neonatal asphyxia have not been evaluated. Under alpha-Chloralose anaesthesia, 17 newborn lambs were asphyxiated until their mean arterial pressures were < or = 25 mmHg. They were then immediately resuscitated, and assigned to two groups. Group I, but not group II lambs received IV bolus of 10 mg kg-1 Naloxone within 5 min of resuscitation. The infusion was continued at the same dose hourly until sacrificed 24 h post-asphyxia. Arterial pH/gases, intracranial/arterial pressures, and rectal temperature were monitored. Neurological examinations were performed on both groups prior to sacrifice, and the blood-brain barrier integrity was assessed by Evans blue. Despite aggressive resuscitation, 5 lambs died during asphyxia, but 12 survived and were assigned according to the protocol. There were no significant group differences in the magnitude of asphyxia, arterial and intracranial pressures. However, blood-brain barrier disruption was observed in 5 out of 6 untreated, and in only 1 of the 6 lambs treated with Naloxone (p < 0.05). Severe neurological abnormalities were observed in 75% of lambs with disrupted, but in none of the animals with intact blood-brain barrier (p < 0.05). Our study suggests that post-asphyxia blood-brain barrier disruption is causally related to poor neurological outcome, and that Naloxone prevents both the disruption, and the neurological dysfunction among those survivors with intact blood-brain barrier.

Deletion mapping of chromosome 8p in prostate cancer by fluorescence in situ hybridization

Double-target fluorescence in situ hybridization (FISH) was applied to 42 cases of prostate cancer and seven cases of histologically proven benign prostate hyperplasia for the detection of structural aberrations of chromosome 8. Cosmid probes for two chromosome 8p loci (LPL/8p22 and D8S7/8p23) were used in 34 specimens of malignant tumors obtained by the touch biopsy technique. Deletion was defined as when the number of cosmid signals was lower than the number of centromere signals in more than 35% of all nuclei observed. In total, thirty of the 42 (71%) specimens demonstrated any type of 8p deletion. Out of the 34 cases in which deletion mapping could be evaluated, distal deletion (D8S7) was detected in 17 (50%), of which 10 also showed deletion of LPL. Deletion of LPL was detected in 18 cases (53%), of which 8 (24%) retained the D8S7 (interstitial deletion). When the deletion pattern was graded as (1) no deletion (2) partial deletion (either D8S7 or LPL deleted) and (3) both deletions, the degree of deletion was well correlated with the tumor grade (P = 0.0009) and with stage (P = 0.0072, Fisher's Exact test). These data support the hypothesis that tumor suppressor gene(s) may be located in the chromosomal region 8p22, hence 8p deletions may play a crucial role in the pathogenesis of prostate cancer.

Milacemide metabolism in rat liver and brain slices by solids NMR

The metabolism of 13C- and 15N-labeled milacemide, 2-(pentylamino)-acetamide, has been studied in rat liver and brain slices using solid-state NMR. This analysis is fast and efficient and can be used to monitor both major and minor metabolic pathways in mammalian tissue culture. The NMR work reported herein involves both conventional cross-polarization magic-angle spinning 13C and 15N NMR spectra and rotational-echo double resonance 13C-15N experiments. The latter measure quantitatively the breaking of isotopically labeled carbon-nitrogen chemical bonds. Our results, which are consistent with suggestions from previous metabolic studies, show that the first step in the breakdown of milacemide is the breaking of the pentylamine nitrogen bond to yield pentanoic acid and glycinamide. Total incorporation of 15N label from the resulting glycinamide fragment is comparable in rat liver and brain. In both tissues, considerably more of the 15N label from glycinamide is incorporated than the corresponding 13C label. Differences between the liver and brain tissue are also observed, with more synthesis incorporating the 13C labels taking place in the liver.

Blood-brain barrier disruption in experimental focal ischemia: comparison between in vivo MRI and immunocytochemistry

The definition of blood-brain barrier (BBB) damage in cerebral ischemia using contrast-enhanced MRI has not been clearly correlated to the spread of edema or other histological measures of barrier disruption. In this study, we used a rabbit model of focal cerebral ischemia to compare GdDTPA-enhanced MRI with spin-echo images of brain injury and immunocytochemical detection of BBB damage and vasogenic edema. After 4 h of transient ischemia followed by 6 h of reperfusion, in vivo T2W and T1W images were obtained in a 1.5 T magnet using a 3-inch surface coil. After MRI, the animals were sacrificed and anti-serum protein (IgG) monoclonal antibodies were used to detect regions of increased BBB permeability to serum proteins. Ischemic neuronal damage was confirmed with cresyl-violet histology. T2W scans showed focal regions of increased signal intensity in the ischemic hemisphere (17.0 +/- 4.1%) that primarily involved the cortex and striatum. T1W scans showed corresponding regions of hypointensity but demonstrated, in general, smaller lesion sizes (10.1 +/- 2.9%). GdDTPA-enhanced images showed variable areas of BBB disruption that included regions of intense leakage as well as lesions that only showed subtle enhancement along the periphery of damaged tissue. It appeared that large and more severe lesions corresponded to peripheral enhancement whereas smaller lesions showed central parenchymal enhancement. The extent of MR contrast enhancement did not correlate well with immunocytochemical images of serum protein leakage. Anti-IgG stains demonstrated widespread regions of BBB damage corresponding with areas of damaged neurons that appeared pyknotic on cresyl-violet sections.(ABSTRACT TRUNCATED AT 250 WORDS)

Prenylation of Rab5 is dependent on guanine nucleotide binding

Rab5 is a small molecular weight GTP-binding protein that functions in endocytic vesicle traffic. Like other Ras-related proteins, Rab5 is prenylated on C-terminal cysteine residues, although it lacks the typical C-terminal CAAX motif (where A is any aliphatic amino acid and X is any amino acid) to direct this post-translational modification. We have investigated structural requirements for the in vitro geranylgeranylation of Rab5. Rab5N133I, a point mutant that has impaired ability to bind GTP or GDP, undergoes modification to a limited extent and at a severely reduced rate when compared to cognate Rab5. A second point mutant, Rab5Q79L, can be processed to approximately the same extent as wild-type albeit at a reduced rate. Since the latter mutation results in defective GTPase activity, these combined observations indicate that guanine nucleotide binding plays an important role in the geranylgeranylation reaction and suggest that the GDP-bound form of Rab5 is the preferred conformation for interaction with Rab prenyltransferase. This idea is supported by the finding that non-hydrolyzable GTP analogs inhibit Rab5 prenylation, while in vitro processing of both H-ras and the gamma 2 subunit of regulatory G proteins is unaffected at concentrations of guanosine 5'-O-(thiotriphosphate) (GTP gamma S) up to 400 microM. Moreover, a truncation mutant lacking the C-terminal cysteines, Rab5(1-211), serves as an inhibitor of Rab5wt geranylgeranylation when liganded with GDP but not GTP gamma S. Thus, the recognition of Rab5 as a substrate by Rab prenyltransferase involves structural elements exclusive of the C terminus and dependent upon the GDP-binding conformation of the protein.

Treatment of twin-twin transfusion syndrome

OBJECTIVE

To determine whether therapeutic amniocentesis may improve outcomes in patients with twin-twin transfusion syndrome.

METHODS

Thirteen patients with possible twin-twin transfusion syndrome were evaluated for treatment. Therapeutic amniocenteses were performed on nine, and four patients were managed conservatively depending on the clinical severity of the twin-twin transfusion syndrome.

RESULTS

Therapeutic amniocenteses resolved the syndrome in three of nine cases, with an overall neonatal survival rate of 83.3% (15 of 18) and neonatal morbidity of 53.3% (eight of 15) among the survivors. The survival rate in patients with expectant management was 75% (six of eight), with a neonatal morbidity of 33.3% (two of six). An association between amniotic fluid status and fetal outcomes was observed. Patients with normalization of polyhydramniosoligohydramnios had the best outcomes.

CONCLUSION

Early, aggressive amniocentesis may be an effective therapy for twin-twin transfusion syndrome. Therapeutic amniocentesis may have the capability to alter inter-fetal blood flow, possibly as a result of changes in intravascular pressure, which are related to changes in intra-amniotic pressure.

Improved method for release of cell nuclei from paraffin-embedded cell material of squamous cell carcinomas

An improved method of releasing cell nuclei from paraffin-embedded highly keratinized squamous cell carcinomas by pretreatment with 85% formic acid-0.3% H2O2 followed by enzymatic treatment with subtilisin Carlsberg is described. After DAPI staining the resulting suspensions of cell nuclei were analyzed by DNA flow cytometry, in addition to microscopy. The total yield of released cell nuclei was improved and the proportion of tumor cell nuclei in the suspensions increased from 12% to 53% using this method compared to the conventional preparation technique. Cytoplasmic residue disappeared nearly completely. Thus, the finding of false aneuploid cell populations representing diploid cells with autofluorescent cytoplasm could be avoided. In addition, even small true aneuploid cell populations could be detected due to the increased proportion of released tumor cell nuclei and the lower proportion of background in the > 2C region.

Cartilage warping: an experimental model

Cadaveric cartilage was cut into blocks with a newly devised cartilage cutter. Over one-hundred pieces of cartilage were used to define a kinetics curve of cartilage warping. Kinetics curves were developed for a control group of cartilage blocks placed in saline-soaked gauze (n = 46). In addition, kinetics curves were developed for cartilage placed in hypotonic saline (n = 14), hypertonic saline (n = 14), and cyanoacrylate glue (n = 6). Photographs of all groups were taken at timed intervals in order to plot the cartilage warping. It was found that pieces of cartilage which were cut peripherally (n = 6) warped twice as much as those cut centrally (n = 40). This was significant to p = 0.001. Within 15 minutes, centrally cut pieces of cartilage warped to approximately 90 percent of their end warpage; on the other hand, peripherally cut pieces of cartilage required 30 minutes to warp 90 percent of their destined warpage. The variables used did not significantly alter the kinetics curves as compared with control.

Cross-links in cell walls of Bacillus subtilis by rotational-echo double-resonance 15N NMR

The cross-link index of peptidoglycan of intact cell walls of Bacillus subtilis grown in media containing L-[2-13C,15N]aspartic acid has been determined by rotational-echo double-resonance 15N NMR. A cross-link index of 72% decreased to 47% when the bacteria were exposed to the antibiotic cephalosporin C. The fraction of 15N label routed from aspartic acid in the media to glutamic acid in the peptidoglycan peptide stems more than doubled for the cephalosporin-exposed cells, indicating interference with general cell wall nitrogen metabolism by the antibiotic.

Effects of argipressin injected into medial amygdaloid body on blood pressure and heart rate in rats

Graded injections of argipressin (Arg, 150, 300, and 600 ng/1.5 microliters CSF, 2 min) into the medial amygdaloid body in anesthetized rats produced a dose-related increase in the mean arterial pressure and heart rate (Maximal delta MAP = 2.9 +/- 1.5 kPa, Maximal delta HR = 67 +/- 38 bpm), which lasting > 40 min at 600 ng dosage. Naloxone (15 micrograms/15 microliters CSF) injected into the lateral ventricle blocked the cardiovascular responses to Arg. These results suggest that Arg exerts a central action on the cardiovascular system via the opioid in the lateral ventricle.

Ultrastructural study of moniliformin induced lesions of myocardium in rats and mice

Effects of moniliformin on the ultrastructure of the myocardium of mice and rats were studied. Mice were given moniliformin orally at a dose of 29.46 mg.kg-1 the LD50. One h after dosing, lesions of the mitochondria of the myocardial cells were found which became more severe in 2 and 3 h. Ultrastructural lesions were also observed in the myofibrils and sarcolemma. Rats were given moniliformin orally at the dosage of 6 mg.kg-1 once daily for 56 d. Lesions of mitochondria and myofibrils were relatively mild. In the myocardiac specimens taken from the 21d post-toxin administration, lesions of the sarcolemma became more obvious. These moniliformin-induced lesions were similar to the ultrastructural changes in the myocardium of patients with Keshan disease. Our findings indicate that there may be a close and important relationship between moniliformin intoxication and Keshan disease.

Hydrogen exchange in native and alcohol forms of ubiquitin

Ubiquitin adopts a non-native folded structure in 60% methanol solution at low pH. Two-dimensional nuclear magnetic resonance (2D NMR) was used to measure the hydrogen-exchange rates of backbone amide protons of ubiquitin in both native and methanol forms, and to characterize the structure of ubiquitin in the methanol state. Protection factors (the ratios of experimentally determined exchange rates to the rates calculated for an unfolded polypeptide) for protons in the native form of ubiquitin range from less than 10 to greater than 10(5). Most of the protons that are protected from exchange are located in regions of hydrogen-bonded secondary structure. The most strongly protected backbone amide protons are those of residues comprising the hydrophobic core. Hydrogen exchange from ubiquitin in methanol solution was too rapid to measure directly by 2D NMR, so a labeling scheme was employed, in which exchange with solvent occurred while the protein was in methanol solution. Exchange was quenched by dilution with aqueous buffer after the desired labeling time, and proton occupancies were measured by 1H NMR of the native form of the protein. Protection factors for protons in the methanol form of ubiquitin range from 2.6 to 42, with all protected protons located in hydrogen-bonded structure in the native form. Again, the most strongly protected protons are those of residues in the hydrophobic core. Comparison of the patterns of the hydrogen-exchange rates in the native and methanol forms indicates that almost all of the native secondary structure persists in the methanol form, but that it is almost uniformly destabilized by 4-6 kcal/mol.(ABSTRACT TRUNCATED AT 250 WORDS)

Mutations in the V2 vasopressin receptor gene are associated with X-linked nephrogenic diabetes insipidus

X-linked nephrogenic diabetes insipidus (NDI) is a rare disorder in which the kidney is insensitive to the antidiuretic hormone, vasopressin. It has been proposed that the kidney-specific V2 vasopressin receptor, a G protein-coupled receptor, is defective in this disorder as both the disease and the receptor map to Xq28. We report six unique mutations in the V2 receptor gene of five unrelated NDI patients, with one patient having two mutations. The most severely affected patient has a nonsense mutation which would terminate the protein in transmembrane domain III. Other mutations include three missense mutations, a frameshift and one small in-frame deletion. These results represent one of the first examples of recessive mutations affecting a G protein-coupled receptor.

[A population-based study on incidence of idiopathic cardiomyopathy in Nanjing, 1985-1989]

The epidemiology of idiopathic cardiomyopathy (ICM) is largely unknown among Chinese population. The purpose of this study was to document the incidence of ICM in the entire residents aged less than 60 years in Nanjing city during the five year period from 1985 to 1989. Using the case registered method it was identified that 275 new cases of ICM collecting from all of the clinically diagnosed outpatients and inpatients in the 14 related hospitals within the city among 2,098,175 residents for years 1985-1989. Over all incidence rate was 2.6 per 100,000 person-years, the age-and sex-adjusted average annual rate being 2.1 per 100,000 directly according to the standardized population of China in 1964 (95% confidence interval 1.9-2.2). This incidence rate was increased from 1.7 per 100,000 in 1985 to 3.3 per 100,000 in 1989 and progressively increasing with aging especially in the groups over 20 years old. Among these 275 patients with ICM, 134 were classified to idiopathic dilated cardiomyopathy (IDCM) and 132 to idiopathic hypertrophic cardiomyopathy (IHCM). Both the average annual incidence rates of IDCM and IHCM were 1.3 per 100,000 and the age-and sex-adjusted rates were 1.1 per 100,000 (95% CI 0.9-1.2) in IDCN and 0.9 per 100,000 (95% CI 0.8-1.0) in IHCM, respectively. The incidence rate of ICM in male was 3.0 significantly higher than 2.2 per 100,000 in female especially in IHCM. The result of this survey is first provided with incidence data of ICM on a broad general population-based study in our country and may be of value in further studying its epidemiology and etiology.

cDNA sequence of a second fibrinogen alpha chain in lamprey: an archetypal version alignable with full-length beta and gamma chains

The message for a second fibrinogen alpha chain has been cloned from a lamprey liver cDNA library. The sequence is unique in that the amino-terminal half is homologous to all other known alpha chains, including another from lamprey, but its carboxyl-terminal half is homologous to the carboxyl-terminal portions of beta and gamma chains, segments that compose the distal globular regions of fibrinogen. The structural pattern of this newly discovered alpha chain suggests that it could be a direct descendant of the archetypal chain that existed prior to the gene duplications that led to unique beta and gamma chains and before the dislocating events that gave rise to contemporary alpha chains.

Antioxidant activity of two dibenzocyclooctene lignans on the aged and ischemic brain in rats

The effects of two dibenzocyclooctene lignans on peroxidative damage of aging and ischemic rat brain were studied. Incubation of eight-month-old rat brain mitochondria and membrane suspension with Fe(2+)-cysteine resulted in the formation of malondialdehyde (MDA) and decrease of ATPase activity. Schisanhenol (Sal) (10(-4) M) completely inhibited the peroxidative damages of brain mitochondria and membrane of rats. The swelling and disintegration of brain mitochondria, as well as the reduction of brain membrane fluidity induced by Fe(2+)-cysteine were also prevented by Sal. The results of imitative experiment of ischemia and reperfusion of brain mitochondria and membrane in vitro indicated that Sal significantly impeded production of MDA and loss of ATPase activity induced by reoxygenation following anoxia. Oral administration of Sal induced increase of cytosol glutathione-peroxidase of brain in mice under the condition of reoxygenation following anoxia. The other compound schizandrin (Sin B) also has similar activity. But its potency is weaker than that of Sal. All these results indicate that Sal and Sin B have protective action against oxidative stress.

Characterization of cross-linking of cell walls of Bacillus subtilis by a combination of magic-angle spinning NMR and gas chromatography-mass spectrometry of both intact and hydrolyzed 13C- and 15N-labeled cell-wall peptidoglycan

Cross-polarization magic-angle spinning 13C and 15N NMR, rotational-echo double resonance 13C NMR, and delays alternating with nutation for tailored excitation-difference 13C NMR spectra have been obtained from lyophilized cell walls of Bacillus subtilis grown on a synthetic medium containing D,L-[2-13C, 15N]aspartate and D-[1-13C]alanine. Label from aspartate is incorporated into D-glutamic acid and m-diaminopimelic acid of cell-wall peptidoglycan, while label from alanine appears in the C-1 positions of both D- and L-alanyl residues. The cross-link index (the fraction of peptide stems joined by an isopeptide covalent bond) is obtained directly from analysis of the results of the 13C NMR experiments. However, specific isotopic enrichments of cell-wall components cannot be obtained from NMR data alone. The latter are determined either from a gas chromatographic-mass spectrometric analysis of the amino acids derived from hydrolysis of cell-wall peptidoglycan, or from a combination of NMR and gas chromatographic-mass spectrometric results. The combined analysis is overdetermined and so involves the least error for evaluations of both the cross-link index and the isotopic enrichments. The cross-link index is 0.33 +/- 0.03 for cell walls of B. subtilis grown in the presence of the antibiotic, cephalothin.

Protection by schisanhenol against adriamycin toxicity in rat heart mitochondria

The effects of schisanhenol (Sal) on Adriamycin (ADM)-induced rat heart mitochondrial toxicity in vitro were investigated. Malondialdehyde formation, lysis, disintegration and membrane rigidification in mitochondria treated with ADM were reduced significantly by Sal. In the electron spin resonance studies, Sal did not affect significantly the formation of ADM semiquinone radicals (AQ.), whereas hydroxyl radicals generated by electron transfer from AQ.to H2O2 were scavenged by Sal dose dependently. These results indicate that Sal could protect against ADM-induced rat heart mitochondrial toxicity.