Stabilization of double-stranded oligonucleotides using backbone-linked disulfide bridges

A convenient, practical route to the synthesis of disulfide-bridged oligonucleotides has been developed. Aliphatic linkers with terminal thiol groups have been attached to the phosphodiester backbones of partially or fully complementary oligonucleotide sequences and oxidized to yield covalently closed oligonucleotides with disulfide bridges. This procedure has been used to prepare a duplex with disulfide bridges at both ends and stem-loop sequences with single disulfide bridges. Oxidation of a self-complementary duplex possessing terminal thiol groups produced both hairpin and duplex structures with disulfide bridges, the relative proportions of each being dependent upon the reaction conditions. These bridged hairpin and duplex structures were shown to be interconvertible by reduction and re-oxidation. The melting profiles of disulfide-bridged oligonucleotides were compared with the same sequences without bridges and with sequences possessing triethylene glycol bridges, and in all cases the introduction of disulfide bridges resulted in a considerable increase in thermal stability. EcoRI endonuclease was capable of cleaving a disulfide-bridged duplex possessing a recognition site for this enzyme, thus supporting a lack of distortion of the recognition site. The disulfide bridges could be cleaved using a large excess of DTT to regenerate the corresponding sulfhydryl compounds. A study of the serum stabilities of disulfide-bridged oligonucleotides showed that the bridged duplexes were much more stable than their unmodified counterparts, whereas the rate of degradation of the stem-loop structures was more dependent upon the size of the loop than the presence or absence of the disulfide bridge. In summary, we have described a novel methodology, employing commercially available reagents, for the stabilization of oligonucleotide duplexes or stem-loop structures by disulfide bridge formation.

Immunosensing with photo-immobilized immunoreagents on planar optical wave guides

Immunocomplexation at wave guiding TiO2/SiO2 surfaces was investigated using an integrated optical grating coupler. For extended application of this label-free monitoring system, F(ab')2 fragments of monoclonal antibodies were photo-immobilized by photolinker polymer-mediated procedures that do not require functionalization of either the immunoreagent or the TiO2/SiO2 surface. Covalent, light-dependent binding of photolinker polymer and F(ab')2 fragments was achieved using a single-step photo-reaction. Bovine serum albumin derivatized with aryldiazirines (T-BSA) served as a photolinker polymer. T-BSA suppressed the non-specific adsorption of analytes to wave guide surfaces. Immunoreagent binding and immunological activity were analyzed and modified surfaces were investigated by scanning force microscopy. Apparent immunoreagent surface densities were 16.7 fmol F(ab')2 per mm2 sensor surface. Optical analyses revealed linear, dose-dependent antigen binding with label free analytes. Immunocompetent surfaces were regenerable by treatment at pH 2.3, rendering the immunosensing system applicable for repetitive use.

[Histopathological and immunohistochemical study of ovarian polyembryoma]

A case of polyembryoma which is rare in ovarian malignant germ cell tumors was reported. Microscopically, numerous and variable embryoid bodies, surrounded by embryonic hepatoid tissues, trophoblastic cells and multiple elements, were observed. The results of immunohistochemical analysis were: (1) alpha fetoprotein (AFP) was not only shown positive in yolk sac cells among the embryoid bodies, in the endoderm and in the margins of the ectodermal cells, but also in multiple elements in the mucinous matrix. (2) Hepatoid tissues reacted positively to AFP and alpha antitrypsin (AAT) as well as to hCG. (3) By using hCG and human placental lactogen (hPL) as markers it is proven that among trophoblastic cells of the tumor, not only syncytiotrophoblastic cells but also the intermediate cells and the cytotrophoblastic cells could be identified.

Endothelial cell seeding of latissimus dorsi muscle pouches

The transformation of skeletal muscle tissue into a fatigue-resistant, autologous blood pump is being explored as an attempt to aid the failing heart. One of the options is to generate a pouch underneath the latissimus dorsi muscle, to connect an electrically conditioned muscle pouch to the circulation, and to use it as an autologous, contractile cardiac assist device. However, the potential of thrombus formation on the blood contacting surface, which is composed of fibrous material, might thwart the clinical usefulness of such skeletal muscle ventricles. We hypothesized that the thrombogenicity of these pouches could be reduced by lining their luminal surfaces with autologous endothelial cells. As a first step, we examined the feasibility of this approach under resting, nonbeating conditions. Using a multistage operative procedure, we isolated microvascular endothelial cells from canine adipose tissue and, after culturing these cells in the laboratory, seeded the autologous cells into preformed latissimus dorsi pouches in six mongrel dogs. Four to six weeks later the dogs were sacrificed and the ultrastructure of the pouches was examined by light and electron microscopy and by fluorescence techniques. The micrographs confirmed that the surfaces of seeded pouches, but not of the untreated controls, are lined with a continuous monolayer of functional endothelial cells, as assessed by the presence of several endothelial cell-specific markers. Current studies are under way to assess the thrombogenicity of these endothelialized skeletal muscle pouches.

Photolinker-polymer-mediated immobilization of monoclonal antibodies, F(ab')2 and F(ab') fragments

Photolinker-polymer-mediated covalent immobilization of antibodies, F(ab') and F(ab')2 fragments has been achieved by light-dependent coupling procedures. Anti-alpha-foetoprotein (anti-AFP) monoclonal antibodies were covalently linked to microplates by layer-coating procedures, which entail antibody photoimmobilization to a photolinker-polymer-precoated surface. In this and the co-coating procedure described, diazirine-functionalized BSA (T-BSA) served as the multifunctional light-activatable linking agent (photolinker polymer). Prior to photo-activation, F(ab')2 or F(ab') fragments derived from anti-(prostate-specific antigen) monoclonal antibodies were mixed and co-coated with the photolinker polymer on to polystyrene microplates. The immunoreagents remained immunologically active after 350 nm irradiation (irradiance 0.7 mW.cm-2 for 20 min). Immuno-responses of photoimmobilized monoclonal anti-AFP antibodies were equivalent to signal intensities obtained with physically adsorbed antibodies. Photoimmobilization of anti-PSA F(ab') fragments in the presence of T-BSA revealed exponential binding characteristics indicating stabilizing molecular co-operativity of the BSA constituent. Co-coating procedures yielded 62 and 65% binding of applied 14C-labelled F(ab')2 and F(ab') fragments respectively. Covalency of antibody binding was inferred from: (i) the strict dependence of photoreagent availability; (ii) the light-dependence of the immobilization process; and (iii) the reversibility of immunocomplexation after acid treatment.

[Three-dimensional computed tomography in the diagnosis of diseases of jaw bone(report of 22 cases).]

3DCT reconstruction,as a new roentnogenographic technique,has not been yet used so much in Oral Maxillofacial Surgery in our country.Scine early 1993,22 cases of 3DCT reconstruction have been performed on a Siemens Plus-s CT scanner for the diagnosis and surgical planning of jaw bone disease and injuries.It demonstrated that 3DCT reconstruction is a useful technique for the diagnosis and surgical planning of jaw bone disease.

Double-stranded cyclic oligonucleotides with non-nucleotide bridges

A series of double-stranded, cyclic oligodeoxynucleotides with non-nucleotide bridges have been synthesized, and their physicochemical properties and susceptibility to enzymes have been investigated. These bridged duplexes are of potential interest for their binding properties to transcription factors and other DNA-binding proteins. Triethylene glycol has been employed as the bridge to alter the lipophilicity of the duplex and avoid the potential for enzymatic cleavage. The synthetic route involved the synthesis of a 3'-phosphorylated, nicked double-stranded precursor with the final internucleotide bond being formed chemically using a water soluble carbodiimide. These bridged duplexes have high thermal dissociation temperatures, and the Tm for a triethylene-bridged 20 base pair duplex was higher than that for the corresponding pentathymidylate-bridged duplex. EcoR I endonuclease cleaved a ligated, bridged duplex at a slower rate than the corresponding unmodified duplex, whereas the unligated, bridged duplex was cleaved more rapidly. Sufficient amounts of the bridged octamer and dodecamer were prepared for proton NMR spectroscopic studies, and 2D COSY and NOESY spectra were obtained. The results indicate that the ligated duplex has a B-form conformation.

p53 tumor suppressor gene mutation in early esophageal precancerous lesions and carcinoma among high-risk populations in Henan, China

To understand whether p53 gene mutation is an early or late event in esophageal carcinogenesis, biopsy samples of esophageal epithelium from symptom-free subjects in a high incidence area, Huixian county of Henan Province, China, were analyzed. Mutations in exons 5, 6, 7, and 8 of p53 were analyzed by single-strand conformation polymorphism analysis and DNA sequencing. Among the 37 biopsy samples showing accumulation of p53 protein in immunohistochemical staining, missense mutations of p53 gene were detected in 1 of 3 samples with normal epithelia, 3 of 23 samples with basal cell hyperplasia, and 4 of 11 samples with dysplasia. All mutations occurred at exon 5 with 3 at codon 175, 2 at codon 176, and 1 each at codons 159, 135, and codon 132. Of the 8 mutations, there were 3 G to A transitions and 3 G to T transversions. To understand the mutation spectrum and possible causative factors of esophageal cancer in this area, surgically resected human primary esophageal carcinomas from Linxian county were analyzed for p53 gene mutations in exons 5, 6, 7, and 8. Mutations were detected in 16 of 29 samples (55%). Twelve samples contained different missense point mutations, with 75% transitions (7 G to A and 2 A to G) and 25% transversions (2 G to T and 1 G to C). Most of the mutations were located at either exon 5 or exon 7. A deletion and an insertion of nucleotides leading to frame-shift mutations were detected in each of two other samples. The results demonstrate that p53 protein accumulation and gene mutation may occur at very early stages of esophageal carcinogenesis. In carcinomas, there was a higher frequency of p53 gene mutations, which accounts for most of the cases with p53 protein accumulation.

The optimization of preparations of competent cells for transformation of E. coli

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Effects of reactive oxygen metabolites on norepinephrine-induced vasoconstriction

Aortic rings, 4 mm in length, were obtained from rats and placed on isometric force transducers in oxygenated Krebs buffer. Following a period of stabilization, the cumulative dose response relationship to norepinephrine was assessed. The vessels were washed and allowed to return to baseline in Krebs buffer containing xanthine (0.5 mM). Xanthine oxidase (0.1 U/ml) was then added to the bath and vessels incubated for 30 min. The vessels were resuspended in Krebs buffer and cumulative dose-response curves to norepinephrine reevaluated. The results indicate that generation of reactive oxygen metabolites by xanthine/xanthine oxidase decreases the pD2 from 7.80 +/- 0.04 to 7.40 +/- 0.09 with the endothelium intact. Removal of the endothelium did not attenuate the contractile dysfunction, indicating that endothelial-derived metabolites were not mediating the loss of vasoconstrictor effectiveness. Maximal tension development did not differ between normal and oxidized vessel rings. Introduction of oxypurinol (0.2 mg/ml) to the bath prevented the loss of constrictor responsiveness, thereby confirming that all of the oxidants were derived from the xanthine/xanthine oxidase reaction. Superoxide dismutase (200 U/ml) partially prevented the loss of norepinephrine responsiveness produced by xanthine oxidase-derived radicals. The pD2 in the SOD + xanthine/xanthine oxidase-treated vessels rings (7.19 +/- 0.11) was significantly lower than control vessel rings (7.49 +/- 0.04) and significantly higher than xanthine/xanthine oxidase-treated vessels (6.89 +/- 0.06). Catalase (1000 U/ml) also partially attenuated the loss of vascular norepinephrine responsiveness.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanism transformation with wavelength of self-pumped phase conjugation in BaTiO(3):Ce

We report what is to our knowledge the first observation of mechanism transformation with wavelength of self-pumped phase conjugation (SPPC) in BaTiO(3):Ce crystals in the near infrared. It was found that the SPPC mechanism changed from a backscattering and four-wave-mixing mechanism to a cat mechanism when the pump wavelength was varied from 706 to 770 nm. In addition, SPPC was obtained when the pump beam entered the crystal by the +c face, and a variation with wavelength of optical beam paths in the crystal was also observed.

[The prognostic value of thyroid stimulating antibodies after antithyroid drug treatment of Graves' disease]

Thyroid stimulating antibodies (TsAb) and thyrotropin releasing hormone (TRH) test were used as the indices for predicting relapse and remission in 58 patients. The variation of TsAb activities was observed before and after antithyroid drug (ATD) treatment. The findings showed that TsAb activities of untreated patients were significantly higher than those of patients treated by ATD, and TsAb activities were weak or negative after ATD treatment. When TsAb was positive or TRH test was abnormal at the time of cessation of ATD therapy, nearly 93% patients relapsed. Further analyses of relapsed patients indicated that there was no correlation between the two indicators, and the TsAb positive rate (84%) was significantly higher than the rate of abnormal TRH test (45%). The average ATD treatment duration in relapsed patients was shorter than that in remission patients. It is concluded that TsAb is more useful than TRH test when they are used for predicting the prognosis of Graves' disease. The duration of ATD treatment could affect relapse or remission. The immunosuppression effect of ATD was also identified.

Molecular mutagenesis induced by glycidyl methacrylate

Glycidyl methacrylate (GMA) is a recently recognized mutagen. In order to explore the mutagenicity and mechanism of GMA, plasmid pBR322 was used for in vitro binding, mutant screening, restriction enzyme mapping, and DNA sequencing. To explore the mechanism by which an initial premutational event is converted into a stable heritable mutation, pBR322 and GMA-bound pBR322 were transformed into E. coli HB101, and the following results were obtained: 1) GMA-bound pBR322 induced phenotype changes in competent cells. Two stable and heritable mutants were isolated (ApRTcS and ApSTcR). 2) When restriction enzyme mapping was used to analyze the mutant ApRTcS, four of seven maps showed changes, but no large DNA insertion or deletion were observed. 3) The frequency of deletion and insertion forms counted about 10%. Sequence specificity and hot spot regions were evident in the sequence analysis of mutated plasmid. The above results indicate that the premutagenic lesions of plasmid induced by GMA can be converted into point mutations in vivo.

Vascular architecture of the human optic chiasma and bitemporal hemianopia

The blood supply system of the optic chiasma was studied in 85 fresh human specimens using various histological and anatomical methods. Computer image analysis and ultrastructural examinations of the microvessel in 58 fetal specimens were also conducted. The authors found that the medial portion of the chiasma is a weak point in the microcirculation network. This weak point is apt to be disturbed first and become ischemic, causing disorders of the crossing optic nerve fibers and resulting in characteristic bitemporal visual field defects. SEM studies showed no ultrastructural difference between the capillaries at the medial and lateral portions of the chiasma. It was concluded that: 1) No special artery supplies the median chiasma the weak point of microcirculation at the median chiasma is due to its relatively scanty capillary distribution; 2) "lateral chiasma arteries" could provide a better blood supply to the lateral fibers and thus the nasal quadrantic visual field could be preserved in many late stages of visual field defect in sellar region tumors; 3) cases with pituitary microadenoma which is not sufficiently large to press the chiasma but involves bitemporal visual field defect are due to the tumor receiving "shunt-flow" (stealing blood) from the chiasma through the peri-infundibulum plexus.

Altered proteolytic processing of the polymerase polyprotein in RNA(-) temperature sensitive mutants of murine coronavirus

We examined the synthesis and processing of the polymerase polyprotein in RNA(-) temperature sensitive mutant of murine coronavirus strain A59. These temperature sensitive mutants of MHV-A59 synthesize viral RNA at the permissive temperature (33.0 degrees C), but are unable to synthesize viral RNA at the nonpermissive temperature (39.5 degrees C). The ts mutants have been mapped to five different complementation groups in the polymerase gene. The 5'-most complementation groups, Groups A and B, map to a region encoding an autoproteinase responsible for the cleavage of p28, the amino-terminal product of the polymerase polyprotein. We screened six temperature sensitive mutants to determine if there was an alteration in the proteolytic processing of the polymerase polyprotein, particularly in the cleavage of the p28 protein. Two mutants, tsNC9 and tsLA16, had altered proteolytic products at both the permissive and nonpermissive temperatures. One Group B temperature sensitive mutant, designated tsNC11, was defective in the production of p28 protein at the nonpermissive temperature. To further localize the site of the mutation in tsNC11, RNA representing the 5'-most 5.3 kb region of the polymerase gene was transfected into tsNC11-infected cells and virus production monitored. The transfected RNA was able to complement the defect in tsNC11, resulting in viral RNA synthesis and production of viral particles at the nonpermissive temperature. These results indicate that a gene product from the 5.3 kb region of gene 1 is required for coronavirus RNA synthesis.

A mathematically designed STS primer without any mismatches for direct sequencing of cosmid DNA clones

We report here a new method for the direct sequencing of large DNA inserts of cosmid clones from human chromosomes using STS primers of 14 nucleotides without any mismatches, which are designed from results of a mathematical analysis. It is clear that STS primer of 14 nucleotides is optimum for direct sequencing of cosmid recombinant DNA clones. We also provide examples of direct sequencing of cosmid clones of human chromosome 21 using these STS primers.

[Mutagenicity study of eight diesel emission samples]

Mutagenicity of eight diesel emission samples were examined by the Microsuspension test. The results showed that four samples were positive, and the others were negative. We also compared the method with the standard Ames test. The data showed that the microsuspension test is sensitive and economical. The microsuspension test method is useful for determining mutagenicity of environmental mutagens.

Evaluating the flow characteristics of artificial pumping devices using nuclear scintigraphy

The design and development of artificial blood pumps require qualitative and quantitative data relative to pump filling, ejection, and wall motion in order to optimize the design and maximize the pattern of blood flow through the pump. To assist in the development of an artificial heart, we utilized radionuclide scintigraphy and a high-resolution gamma camera to evaluate the flow patterns through the pump. We performed a comparative analysis of the flow patterns in a pneumatically driven ventricular assist device (Sarns/3M VAD) and the electrically driven Milwaukee Heart. These analyses disclose some significant differences between the two devices with regard to the blood sac compression patterns and ejection as well as valvular regurgitation. On the basis of these findings, nuclear scintigraphy for analyzing fluid shear stress and flow dynamics seems a useful technique for evaluating blood flow through artificial blood pumps. Because the procedure does not require a translucent casing or direct contact with the device being studied, it would be especially useful in evaluating artificial blood pumps implanted in patients with heart failure.

Accumulation of p53 protein in human esophageal precancerous lesions: a possible early biomarker for carcinogenesis

The level of p53 protein was determined immunohistochemically in normal tissues and tissues with different severities of lesions (basal cell hyperplasia, dysplasia, carcinoma in situ, and carcinoma) from surgically resected human esophagi and esophageal biopsies of symptom-free subjects. The samples were from an area with high esophageal cancer incidence in northern China (Linxian and Huixian in the Henan province). Tissue sections were incubated with p53 antibodies for immunostaining. Conventional hematoxylin and eosin stain was also used. In surgically resected esophageal specimens, elevated p53 protein levels were found in the cell nuclei in tissues with precancerous and cancerous lesions. From basal cell hyperplasia to dysplasia to carcinoma in situ, the p53 immunostain-positive cells increased in number, and their distribution had roughly the same pattern as that of the proliferating cells. However, positive stain was not observed in the dividing basal cells of the normal epithelium of the surgically resected tissues. A similar pattern of immunostaining was observed in the abnormal tissues of the biopsy samples from the symptom-free subjects. An intriguing observation is that some p53 immunostain-positive cells were observed in 3 of 6 cases of histologically normal epithelia of biopsy samples. Only the papillary immunostaining pattern was observed in these three "normal" cases. Although the molecular basis for such positive stain remains to be investigated, it is possible that p53 protein accumulation occurs early in the pathogenesis of esophageal cancer and that p53 mutation is closely associated with the initiation of this cancer. The accumulation of p53 protein may be a promising early biomarker for identifying high-risk subjects for esophageal cancer.

Hydrophobicity of oligopeptides having un-ionizable side chains

The hydrophobicity of any peptide is a physicochemical property not only of the amino acid sequence, but also of the secondary and tertiary structure. It is also an essential factor to consider in peptide drug delivery, which has become increasingly important in recent years with the discovery of many peptides with potential pharmaceutical uses. The hydrophobicities (log P) of dito pentapeptides reported by Akamatsu and Fujita have been correlated with 12 parameters including 7 indicator variables. We have tried to simply this equation by using more common and simple parameters. Good correlations have been obtained for log P with a five-parameter equation using the sum of the hydrophobicity of component amino acids (log Paa), molecular weight (log MW), the frequency of beta-turn formation (F beta) of peptides, which is an important tertiary structural parameter, the dipole moment (mu) calculated with a computer-assisted program, and the number of amino acids in a peptide (N). This equation should be useful in drug delivery in predicting the relative hydrophobicity of new peptides with no ionizable side chains.

Phenotypic conversion of SV40-immortalized human diploid fibroblasts to senescing cells by introduction of an antisense gene for SV40-T antigen

Normal human lung fibroblast diploid cells, WI-38, become senescent after a definite number of divisions. VA-13 is a line of immortalized cells established by transformation of WI-38 cells by SV40 virus. To determine whether SV40 large T (SV40-T) antigen is essential for this immortalization of WI-38 cells we introduced an antisense gene for T antigen into VA-13. Two morphologically different types of antisense transformant (VA-AS5-8 and VA-AS37-8) were obtained. In both antisense transformants the expression of T antigen was reduced by more than 70% as compared to that in the parent cells. The morphology of the antisense transformants indicated a partial conversion to the senescent phenotype of WI-38. The relative number of cells in the S phase of the antisense transformants was decreased as compared to that in cultures of VA-13 and about 50% of cells were at G1/0. The doubling time of the transformants was prolonged to close to the doubling time of WI-38. The level of expression of retinoblastoma protein (pRB) complexed with SV40-T antigen of the antisense transformants was significantly decreased although the level of total pRB was much higher than that in VA-13. The pRB was present exclusively in the underphosphorylated form. Thus, the decreased level of formation of the complex between SV40-T and pRB or the underphosphorylation of pRB may explain the suppression of growth of antisense transformants. Together, these results show that an antisense gene for SV40-T antigen can efficiently block the cell proliferation and the cell immortalization of VA-13 cells.

Inhibition of expression of a mouse alpha-globin gene by plasmids that include antisense oligonucleotides

Plasmid-borne DNAs, corresponding to 68-base oligodeoxynucleotides, synthesized in the antisense or sense configuration and based on the nucleotide sequences of various regions of the mouse alpha-globin mRNA, were introduced with the gene for xanthine-guanine phosphoribosyl transferase from E. coli (Ecogpt) into mouse erythroleukemia (MEL) cells by protoplast fusion. Specific inhibition of the synthesis of alpha-globin was observed only in the cells transformed with the plasmids with antisense 68-mers that corresponded to the cap site as well as the site of initiation of translation of alpha-globin mRNA (Oligo-A); Other plasmids with antisense 68-mers that corresponded to the regions of the exon/intron junctions, the individual exons, or the 3' untranslated region were ineffective. This antisense RNA efficiently reduced the production of alpha-globin to 9-18% of the endogenous level after induction with hexylmethylene-bis-acetoamide (HMBA). Moreover, most of the antisense transformants did not show any decrease in the expression of the c-myc gene at the early phases of differentiation of MEL cells. Thus, we propose a hypothesis that the early decline in levels of c-myc mRNA may be independent of and uncoupled from the program of globin synthesis during the differentiation of MEL cells.

Light–Dependent, Covalent Immobilization of Biomolecules on ‘Inert’ Surfaces

We describe a novel, versatile procedure for the light-dependent immobilization of ligands to 'inert' material surfaces. Covalent immobilization of ligands differing in chemical nature and complexity is accomplished under mild and non-destructive conditions. Topical interaction of ligands with organic or inorganic surfaces is mediated by photoactivable polymers with carbene generating trifluoromethyl-aryl-diazirines which serve as linker molecules. Light activation of aryl-diazirino functions at 350 nm yields highly reactive carbenes, and covalent coupling is achieved by simultaneous carbene insertion into both the ligand and inert surface. Thus, reactive functional groups are not required on either the ligand or the supporting material. These procedures are applicable whenever ligands, from molecules to cells--synthetically or genetically produced, or isolated from biological sources--need to be immobilized for improved performance.

[Effect of noise on blood pressure of various types of rats]

Before the experiment, male Wistar rats were divided into two types (A and B) according to the different responses of their ECG and Heart Rate (HR) to 1 hour noise exposure: in type A, the ST segment elevated and HR decreased significantly during the exposure; in type B, both ST segment and HR showed no considerable variation. We exposed type A and B wistar rats and spontaneously hypertensive rats (SHRs) of 105 dB steady-state noise, 4 hours per day, 6 days per week. The results showed that after 3 weeks of noise exposure, the mean systolic blood pressure (BP) of type A rats was significantly higher than that of type B and control rats. This higher BP retained progressively till the end of observation (35 weeks); while there were not significant changes of BP in type B rats during the period of 35 weeks noise exposure. We also found that when exposed to noise for 14 weeks, the SHRs in exposure group had markedly higher mean systolic BP than those in control group. The results indicated that noise may affect BP of both Wistar rats and SHRs. There is probably a difference in the susceptibility of BP response to noise. The susceptibility of the BP of rats in type A to noise is greater than that of rats in type B.

Basic fibroblast growth factor (bFGF) immunolocalization in the rodent outer retina demonstrated with an anti-rodent bFGF antibody

The distribution of bFGF in mouse and rat retinas was established using an antibody generated against a rat specific bFGF sequence. The patterns established with this antibody were distinctly different in comparison to the immunostaining patterns using antibodies prepared against similar regions of bovine and human bFGF sequences. Using the anti-rat antibody, at postpartum day 5, both species demonstrate bFGF-like labeling in the outer retina, primarily associated with developing photoreceptors. The anti-rat bFGF antibody in the adult mouse produces intense labeling at the level of the photoreceptor outer segment, whereas in the adult rat, Müller's cells and RPE were intensely labeled but the photoreceptors appeared to be unlabeled. In contrast, the bovine and human antibodies consistently label ganglion cells in both mouse and rat retinas, cells in the inner aspect of the inner nuclear layer and developing horizontal cells, whereas no photoreceptor labeling was observed. These results suggest that minor species differences in a short segment of the bFGF molecule used to generate these antibodies may result in major differences in apparent bFGF-like immunolocalization.

Biopathologic characteristics of DNA content in crypt cells of transitional mucosa adjacent to carcinomas of the rectum and rectosigmoid

The transitional mucosa (TM) adjacent to carcinomas of the large bowel shows histologic and mucin histochemical changes that may indicate premalignant change and may be of prognostic value after radical resection. In this study, 10 anterior resection specimens from patients with carcinomas of the rectum and rectosigmoid were used to compare the nuclear DNA content in TM with those in cancer tissue and with those in nontransitional mucosa (N-TM; i.e., uninvolved mucosa remote from tumors showing normal histologic and mucin histochemical features). The nuclear DNA content was assessed using DNA image cytometry on Feulgen-stained sections. As compared with N-TM, crypts in TM contained greater numbers of cells, were elongated, and were more likely to be branched with marked sialomucin secretion, accompanied by a marked reduction in the normal sulfomucin content. The mean nuclear DNA content in the upper, middle, and lower thirds of crypts was significantly higher in TM than in N-TM, and the nuclear DNA content in TM exhibited no correlation to that in tumors. The results suggest that TM adjacent to carcinomas of the rectum and rectosigmoid has higher proliferative activity, providing further evidence that TM may be an unstable premalignant change.

In vitro assessment of the Milwaukee Heart and right to left balance

A new, electrically powered, total artificial heart, the Milwaukee Heart, has been developed. This device is undergoing testing in vitro. The unidirectional motion of the brushless DC motor (BDCM) affords easier motor control and reduces energy demand. Motors with a unidirectional motion have a longer life than those with bidirectional motion. This device requires less power due to the highly efficient mechanical design. It consumes 6.5 W of power at an average flow of 5 L/min into 100 mmHg of mean aortic pressure and 20 mmHg of mean pulmonary pressure. Pumping at 8 L/min it requires 9.6 W of power. The maximum pump flow is 10 L/min and overall efficiency is 20%. A slotted optocoupler is used to determine the position of the pusher plate at the start of left systole. The number of revolutions that the BDCM makes is counted from this position. There are 50 revolutions of the BDCM per stroke (using a 50:1 gear reducer connected to the motor). The position of the pusher plate is determined from the number of BDCM revolutions. Based on where the pusher plate encounters resistance from the bladder, the force on the left pump is increased or decreased. Left to right balance has been achieved by reducing the size of the right pusher plate in conjunction with varying right stroke volume. In vitro tests show that this new, electrically powered artificial heart provides reliable performance and satisfactory hemodynamic results.

Transitional mucosa at anastomosis. A cause of local tumor recurrence in patients with rectal cancer after anterior resection

Transitional mucosa adjacent to colorectal cancers is essentially characterized by an excess of sialomucins at the expense of the normally predominant sulphomucins in epithelial cells lining the intestinal crypts which presents the early stage of oncogenic transformation of colorectal epithelium. The presence or absence of sialomucins at the resection margins was studied histochemically using the high iron diamine-alcian blue(HID-AB) stain in 64 rectal cancer patients in Dukes' B stage who underwent curative anterior resection. The correlation was revealed between the presence of sialomucins at the resection margins and subsequent development of local tumour recurrence. Fourteen of 27 patients (51.9%) with sialomucins predominant pattern at either resection margin developed local recurrence compared with 4 of 37 patients (10.8%) with sulphomucins predominant pattern (P less than 0.001). It is suggested that determination of the transitional mucosa around anastomosis in patients treated for the rectal carcinoma by anterior resection appears to identify those with a higher risk of local recurrence.

Aging of the human retina. Differential loss of neurons and retinal pigment epithelial cells

The impact of aging on cell loss in the human retina was examined in foveal and temporal equatorial regions in eyes from 35 donors with ages spanning a 78-yr period from the second to the ninth decade of life. Equatorial cones and retinal pigment epithelial cells (RPE) decreased at uniform rates from the second to the ninth decade, 16 and 14 cells/mm2/yr, respectively. Equatorial rods and cells in the ganglion cell layer (GCL) showed nonuniform rate decreases with age. The rates of rod and GCL cell loss were faster between the second and fourth decades (970 and 9 cells/mm2/yr, respectively) than between the fourth and ninth decades (570-330 and 6-3 cells/mm2/yr). The rod and GCL cell densities at the temporal equator maintained a constant ratio (rods-GCL cell ratio = 103 +/- 0.4, mean +/- standard deviation) and the same reduction slope ratio at different times during aging. Thus, the equatorial rod and GCL cell losses were correlated statistically. The ratio of equatorial photoreceptors to RPE cells showed no significant change with age, suggesting parallel loss of these closely apposed cells. At the foveal center, the variability of cone density between individuals in each decade grouping was large (1.7- to threefold). No significant differences were found in cone or RPE cell densities at the foveal center from the second to ninth decade, suggesting that the densities of foveal cones and RPE cells were stable throughout this period. Foveal RPE density was significantly higher than equatorial RPE density in each age group. No significant difference was found between the equatorial photoreceptor-RPE ratio and foveal cone-RPE ratio in any age group. Cells in the GCL in the fovea decreased by approximately 16% from the second to the sixth decade. These results indicated that (1) rod photoreceptors and cells in the GCL were more vulnerable to loss during aging than cones; (2) photoreceptors and RPE cells showed parallel changes during aging; and (3) the photoreceptor loss accompanying aging was less pronounced in the fovea than in the peripheral retina.

Quantitative structure-activity relationship (QSAR) analysis of the cytotoxicities of aminohydroxyguanidine derivatives and their antiviral activities in vitro

Substituted Schiff bases of 1-amino-3-hydroxyguanidine (SB-HAG) were tested for the first time against noninfected T4 lymphocytes (CEM-6 cells) and the same cell line infected by HIV-1 in vitro. Twenty-one of 23 compounds at micromolar levels did not inhibit the growth of the noninfected T4 cells, suggesting minimal cytotoxicity. The antiviral effects of these compounds in a micromolar concentration range have been shown to be nonsignificant (less than 30%) against HIV-1. Three-dimensional parameter focusing of the physicochemical properties (i.e., log P and VW) and the marginal antiviral activities shows that the marginally active compounds lie in a region different from the inactive compounds. QSAR analysis of the two subsets shows that the cytotoxicity correlates well with the electronic and lipophilic parameters. The results of the QSAR analysis can serve as guidelines for further structural modification of this series of compounds to minimize the cytotoxicity against host cells.

[A study using FRTL-5 cell for detecting thyroid stimulating antibody activity in serum in patients with Graves disease]

Using a strain of functioning rat thyroid cells (Fischer rat thyroid line-5, FRTL-5) as target cells and immunoglobin G sedimented from serum by polyethylene glycol (PEG), we studied thyroid stimulating antibody (TsAb) activity in serum of patients with Graves' disease. In a total of 92 cases, TsAb activity was detected in 92.59% (25/27) of the patients with untreated Graves' disease, 75.00% (9/12) of the patients with relapsing Graves' disease and 39.13% (18/46) of the patients with Graves' disease who were euthyroid while taking antithyroid drugs. TsAb activity was also detected in 42.86% (3/7) of the patients with ophthalmic Graves' disease and 12.50% (2/16) of the patients with Hashimoto's thyroiditis. The results showed that TsAb activity can be used as an immunologic index and is valuable in the diagnosis of Graves' disease. Remission and relapse of Graves' disease can be indicated or monitored with the measurement of TsAb activity.

Application of a new nuclear scintigraphy camera to evaluate flow and mechanical pumping of artificial hearts

To assist in the development of an artificial blood pump, The Milwaukee Heart (MH-1), a new nuclear scintigraphy camera was used to study the wash-in and wash-out patterns of the MH-1. These studies indicate the MH-1 has an ejection fraction of 59.3%, with a stroke volume of 72 +/- 3 ml, and an afterload of 130 mmHg. Flow through the device is highly uniform, with no areas of stagnation. Regional ejection fraction images demonstrate homogeneous ejection from apex to base. The ability to scan through the first pass images allows study of wash-in, mixing, and wash-out of the tracer. In conclusion, this technique may provide a new approach to evaluating artificial heart pumps.

Physical factors contributing to the partition coefficient and retention time of 2',3'-dideoxynucleoside analogues

Acquired immunodeficiency syndrome (AIDS) is an immunosuppressive disease characterized by an immune impairment and a high susceptibility to unusual forms of certain neoplasms. Since the brain is an important site of the infection, it is necessary to explore new classes of drugs that have the ability to penetrate across the blood-brain barrier, and the potency to suppress viral replication within the central nervous system (CNS). Therefore, the ability to predicate the lipophilicity of the potent anti-AIDS drugs may provide useful information about the potential of the drugs to enter CNS. In this paper, the correlations of log P (octanol-buffer partition coefficient) and log tR (retention time in HPLC; Rt was used by Balzarini et al.) with some physical constants like log MW (molecular weight), hydrogen bond forming ability (HB) of the substituents, and the substituent group dipole moments (mu) are analyzed. Good correlations of log P and log tR with log MW, HB, and mu have been obtained.

Quantitative structure-activity relationship analysis of combretastatins: a class of novel antimitotic agents

Combretastatins and their synthetic analogues, having structural features resembling that of colchicine, also have similar modes of action. In this report we have correlated the cytotoxicity of combretastatins against the murine leukemic cell line L1210 with physicochemical parameters such as the summation of the Hansch-Fujita pi constant, which was used as an index of lipophilicity of the substituent groups on ring A (sigma pi a) and ring B (sigma pi b), the vector summation of the group dipole moments of ring A (sigma mu a) and ring B (sigma mu b), the nature of the linker chain between ring A and ring B (Bt-L), indicator parameters (NOH)a and (NOH)b, which represent the number of hydroxyl groups on ring A and ring B, respectively, and the summation of pi values of the substituents on the linker (sigma pi L). Cytotoxicity correlated well with (sigma pi b), (NOH)a, (Bt-L), and (sigma mu b), and the dependency on (sigma pi b) was found to be parabolic.

Clinical observations on acupuncture treatment of peripheral facial paralysis aided by infra-red thermography--a preliminary report

We have carried out clinical observations on 34 patients with peripheral facial paralysis treated by acupuncture therapy prescribed according to selection of treatment regimen on the basis of facial thermogram and temperature. A comparison was made with a control group of 97 patients who received conventional acupuncture therapy only. It was found that 1) The cure rate in the group of selecting acupoints by thermogram (hereinafter referred to as the thermography--aided treatment group) was 67.65%, with a marked improvement rate of 26.40%; while the cure rate of the conventional acupuncture treatment group (hereinafter called the conventional treatment group) was 46.39%, the marked improvement rate being 29.90%, indicating a significant difference in therapeutic efficacy between the two groups (P less than 0.02). 2) The average duration of acupuncture therapy for the thermography aided treatment group was 6.02 weeks, whereas that for the conventional treatment group, 24 weeks. There was also a significant difference between the two groups (P less than 0.01). And 3) During the entire therapeutic course, 25.2 sessions of treatment were given on the average in the thermography--aided treatment group, and 78.8 sessions in the conventional treatment group, showing a very significant difference (P less than 0.001). The present thermography--aided method exhibits advantages over the conventional one in enhancing the cure rate and shortening the duration of treatment, which is worthy to be popularized in clinical practice. And it is also of certain significance in standardization and scientification of acupuncture therapy.