[Progress in the study of chymase]

Chymase is a kind of serine proteinase, mainly exists in secretory granules of mast cell and extracellular interstitium. The mature enzyme is a glycoprotein comprising 226 amino acid residues, with molecular weight of 30 kD. It can be inhibited by serine proteinase inhibitors but not by angiotensin I converting enzyme inhibitors. The cDNA and genomic DNA of human chymase were cloned and sequenced. Chymase has close relations with neurogenic inflammation, extracellular matrix catabolism, control of vasoactive peptide metabolism, and so on. It plays an important role in angiotensin II formation in human heart.

Existence of phosphorylated and dephosphorylated forms of cytosolic thymidine kinase (TK1)

In this study we examine whether different TK1 variants of pI 6.9 and 8.3 found by isoelectric focusing gel electrophoresis (IFE) reflect just a phenotype difference due to phosphorylation modifications or have a real phenotypic background. The phosphorylation degree of purified TK1 variants was analyzed by determining the changes in the pI values after treatment with alkaline phosphatase, using IFE. The genetic origin of the two TK1 variants was studied by determining their mol wt. by means of SDS-gelelectrophoresis. Furthermore, the subcellular distribution of the two TK1 variants was also studied. Alkaline phosphatase treatment changed the pI value of purified TK1 from 6.9 to 8.3. No change in the pI value was found when purified TK1 corresponding to pI 8.3 was treated in the same way. Similar results were obtained when treated a cytosolic fraction with alkaline phosphatase. Antibody raised against the C-terminal part of human TK1 only recognized the dephosphorylated TK1 variant corresponding to pI 8.3. There was no difference in the molecular weight between the two TK1 variants. Thus, we concluded that the TK1 variants corresponding to pI 6.9 and 8.3 are of the same genetic origin, but consist of phosphorylated and dephosphorylated forms.

Open-angle glaucoma and blood groups. The Barbados Eye Study

OBJECTIVE

To evaluate the association of open-angle glaucoma (OAG) with ABO, Rh and Duffy blood groups in the population-based Barbados Eye Study.

DESIGN

Case-control study.

SETTING AND PARTICIPANTS

A subset of black Barbados Eye Study participants, which included 199 OAG cases and 1063 controls.

DATA COLLECTION

ABO, Rh and Duffy blood groups were determined as part of a comprehensive study visit, which included assessment for OAG through perimetry, fundus photography, and ophthalmologic examination.

OUTCOME MEASURES

Comparison of blood groups between OAG cases and nonOAG controls, expressed as odds ratio and 95% confidence intervals.

RESULTS

Associations were found with the Duffy Fya+ group, which is more frequent in white than black populations. In Mantel-Haenszel analyses, OAG was positively associated with Duffy Fya+ in men (odds ratio, 2.67; confidence interval, 1.52 to 4.69) and in persons with intraocular pressure more than 21 mm Hg (odds ratio, 3.32; confidence interval, 1.49 to 7.38). Logistic regression analyses confirmed these findings (interaction of Duffy Fya+ and male gender, P = .01; interaction of Duffy Fya+ and intraocular pressure, P = .04). No associations between OAG and the ABO or Rh blood groups were seen.

CONCLUSIONS

The associations with Duffy Fya+, which had not been reported previously in a black population, support the involvement of genetic factors in OAG. However, the lack of association between OAG and blood group markers of African ancestry is inconsistent with a genetic explanation for the differences in OAG prevalence between blacks and whites. Our findings suggest gene-environment interactions in OAG, to be explored by further studies of OAG and Fy markers by racial group and gender.

Role of CD44 in the reaction of vascular smooth muscle cells to arterial wall injury

CD44, the principal receptor for hyaluronic acid, is a widely distributed cell surface proteoglycan involved in cellular activation, proliferation, and migration. These processes are also central to the vascular smooth muscle cell's response to arterial wall injury. We evaluated the expression of CD44 and its isoform, CD44-V6, on vascular smooth muscle cells in vitro and in vivo and assessed the role of CD44 in DNA synthesis. Cultured vascular smooth muscle cells expressed CD44 and CD44-V6 at levels equal to or higher than those of the beta 1 and beta 2 integrins. In a rat carotid artery balloon injury model, CD44 and CD44-V6 mRNAs were unregulated in vascular smooth muscle cells after injury, and CD44 protein expression was greatest at the luminal edge of the growing neointima. CD44-expressing smooth muscle cells proliferated actively, and hyaluronic acid expression increased after injury in a temporal pattern similar to that of CD44. Through binding to hyaluronic acid, CD44 augmented DNA synthesis in cultured human and rat smooth muscle cells by 48 +/- 7.8 and 100 +/- 12.5%, respectively, an effect inhibited by an anti-CD44 antibody that blocked hyaluronate binding. These observations support a role for CD44 in the reaction of vascular smooth muscle cells to arterial wall injury.

[Experimental study on antibacterial activity of subdermal vascular network island skin flap]

A comparison study was carried out on the antibacterial activity between two kinds of pig buttock flaps: the conventional island skin flap and the subdermal vascular network island skin flap which was created by thinning the distal half of a conventional island flap, preserving its subdermal vascular network. Antibacterial activity was evaluated by bacterial counts, phagocytic index and intracellular bacterial killing ratio of leukocytes, skin temperature, laser Doppler, ink perfusion, microangiography and transparent specimen technique. The results indicated that antibacterial activity of the subdermal vascular network island skin flap was much lower than that of the conventional island skin flap. The reduced blood supply and decreased leukocyte function were responsible for the low antibacterial activity after the conventional island flap was thinned.

Effects of nifedipine, metronidazole, and nitric oxide donors on spore germination and cell culture infection of the microsporidia Encephalitozoon hellem and Encephalitozoon intestinalis

Two species of microsporidia, Encephalitozoon hellem and Encephalitozoon intestinalis, were isolated from AIDS patients and cultured in green monkey kidney cells. A spore germination assay and a cultured-cell infection assay were used to test the efficacy of candidate antiparasitic agents. The calcium channel blocker nifedipine, metronidazole, and two nitric oxide (NO) donors, S-nitroso-N-acetylpenicillamine and sodium nitroprusside, were tested in the two assays. Nifedipine (10(-8) M) significantly inhibited E. hellem spore germination in three of four germination media. Metronidazole (10(-5) M) inhibited germination weakly and significantly inhibited E. intestinalis germination in a single germination medium. The inhibitory effect of nifedipine and metronidazole used together was greater than the sum of the effects of the drugs used alone in all E. hellem germination assays. The NO donors also inhibited spore germination. The inhibitory effect of nifedipine and metronidazole could be reversed by washing the spores, while that of the NO donors was not reversible. In early cultured-cell infections, both nifedipine (10(-8) M) and metronidazole (10(-5) M) significantly reduced the number of cells being infected. As the infection spread, these agents were less effective. Some inhibition of the spread of the infection was also demonstrated with the NO donors at a concentration (10(-5) M) not obviously toxic to the cultured cells. These data suggest that combination drug therapy targeting spore germination and intracellular parasite development is promising.

Detection of Bordetella pertussis by polymerase chain reaction and culture in the nasopharynx of erythromycin-treated infants with pertussis

BACKGROUND

Pertussis is a highly contagious respiratory disease and the most serious effects occur in young infants. Recently it has been shown that rapid and highly specific PCR can be a useful diagnostic tool for detection of pertussis infection. To our knowledge there are no previous studies concerning the disappearance of Bordetella pertussis DNA from the nasopharynx during antimicrobial treatment.

METHODS

We studied prospectively how rapidly live B. pertussis organisms and DNA of these bacteria disappear from the nasopharynx during erythromycin therapy in unvaccinated infants. Eighty-five nasopharyngeal swabs obtained from nine erythromycin-treated infants with pertussis on consecutive days during hospitalization were tested by PCR and culture. The PCR products were further analyzed by Southern hybridization.

RESULTS

On the fourth day of treatment 56% of the samples were positive by culture and 89% by PCR, whereas after 7 days the rates were 0 and 56%, respectively. In seven of nine patients PCR remained positive for 1 to 7 days longer than culture. The follow-up study also showed the semiquantitative nature of the PCR assay. The intensity of the PCR products in agarose gel usually weakened with time during erythromycin therapy.

CONCLUSIONS

The results of this study show that PCR assay can achieve the specific diagnosis of pertussis infection in a large proportion of infants even when antimicrobial treatment has killed the organisms and culture is no longer positive.

[Experimental study on "three-dimensional" culture of scar-derived fibroblasts]

Based on the monolayer cell culture system, we resuspended the scar-derived fibroblasts in a solution of polymerizing collagen to develop a "three-dimensional" cell culture system. In this system, cells, extracellular matrices and various modulating factors were associated to form an organic entity, in which the fibroblasts express their biologic characteristics similar to that in living body. With the three-dimensional system, we could study not only the morphology, proliferation and metabolism of fibroblasts, but also their cytophysiology, such as the role on connective tissue contraction. We recommend this culture system as a better model in the research of wound healing and scar formation.

[The effects of histamine H2 receptor agonist, antagonist and antineoplastic agent on the in vitro growth of PB CFU-GM from normal individuals and HL-60 leukemia cells]

Colony forming unit of granulocytes and macrophages from peripheral blood (PB CFU-GM) represents stem and/or progenitor cells from human blood. In this paper, the effects of histamine H2 receptor agonist 4-methylhistamine (4-MH) and its antagonist ranitidine (Ranit) on the growth of PB CFU-GM cultured in methylcellulose system were studied and their differential effects on normal PB CFU-GM and leukemic HL-60 cells were compared with the effect of the antineoplastic agent cytosine arabinoside (Ara-C). It was found that the histamine H2 receptor agonist 4-MH stimulated the growth of PB CFU-GM when 4-MH was added at the concentrations from 10(-9) mol.L-1 to 10(-6) mol.L-1 among which the dose 10(-8) mol.L-1 exerted most potent stimulating effect (the PB CFU-GM colony numbers was 137.68% +/- 8.20% vs the control, P < 0.01). In contrast, the antagonist Ranit showed inhibitory effect on the growth of PB CFU-GM when at the concentrations 10(-9)-10(-5) mol.L-1 cultured for 14 d in the same methylcellulose system. The inhibition rate was 23.73% +/- 1.16% (10(-9) mol.L-1) and 41.42% +/- 6.75% (10(-6) mol.L-1), respectively. Although both Ranit and Ara-C could inhibit the growth of PB CFU-GM in vitro, Ranit exerted much greater inhibition on HL-60 leukemic cells than on normal PB CFU-GM at the dose of 10(-6) mol.L-1 (100% inhibition for HL-60 and < 50% inhibition for PB CFU-GM). However, the inhibition rate of Ara-C for both HL-60 and PB CFU-GM was 100% at the intensive chemotherapeutic dose of 10(-5) mol.L-1. It would appear that the histamine H2 receptor agonist 4-MH possesses stimulating effect on the growth of PB CFU-GM similar to its effect on CFU-GM from bone marrow as documented before. It is suggested that the histamine H2 receptor antagonist Ranit has, to some extent, potential in the treatment of myeloid leukemia, especially when combined with antineoplastic agent Ara-C at suboptimal doses.

[Method of designing a mold for processing corneal lenticules in epikeratophakia with excimer laser]

PURPOSE

To design a mold for processing optical power in epikeratophakia.

METHOD

With excimer laser a corneal graft with appropriate optical power shall be got on the formula of the mold's radius curvature.

RESULTS

Based upon the formula from the data, a 12D mold was accomplished to obtain a suitable cornea lens for epikeratophakia.

CONCLUSION

The 12D mold presents the value to some extent in processing the desired optical power of corneal graft for those patients requiring epikeratophakia.

The perioperative use of ceftriaxone as infection prophylaxis in neurosurgery

An open label study was conducted in the department of neurosurgery, Beijing Tiantan Hospital in China to determine the incidence of postoperative infections following the use of one or two doses of ceftriaxone administered perioperatively. A total of 343 patients, who required neurosurgery and had satisfied the inclusion criteria, was recruited during a 12 month study period. Of these 343 patients, there were 97 and 107 cases of malignant and benign tumours, respectively, 52 cases of aneurysm, 34 cases of arteriovenous malformation, and 53 other cases who underwent neurosurgery for drainage of sub-dural haematoma, relief of cerebral oedema and other indications. A total of 6 (1.75%) cases of postoperative infection was observed, of which 4 were found in the malignant tumour group, and 2 in the arteriovenous malformation group. All six patients were suffering from meningitis. During the 12 month period immediately prior to the present study, when postoperative penicillin and gentamicin was administered twice daily for 5-7 days as regular prophylaxis against infection, the incidence of postoperative infection was 7.2% in the same department managed by the same staff. Results of our present study suggest that one to two doses of ceftriaxone administered perioperatively are effective in reducing the rate of postoperative infections.

Monoclonal antibodies to CD44 and their influence on hyaluronan recognition

Antibodies to CD44 have been used to inhibit a variety of processes which include lymphohemopoiesis, lymphocyte migration, and tumor metastasis. Some, but not all, CD44-mediated functions derive from its ability to serve as a receptor for hyaluronan (HA). However, sites on CD44 that interact with either ligands or antibodies are poorly understood. Interspecies rat/mouse CD44 chimeras were used to analyze the specificity of 25 mAbs and to determine that they recognize at least seven epitopes. Amino acid substitutions that resulted in loss of antibody recognition were all located in the region of homology to other cartilage link family proteins. While at least five epitopes were eliminated by single amino acid replacements, multiple residues had to be changed to destroy binding by other antibodies. One antibody was sensitive to changes in any of three separate parts of the molecule and some antibodies to distinct epitopes cross-blocked each other. Certain antibodies had the ability to increase HA binding by lymphocytes but this did not correlate absolutely with antibody specificity and was only partially attributable to CD44 cross-linking. Antibodies that consistently blocked HA recognition were all sensitive to amino acid changes within a short stretch of CD44. Such blocking antibodies interacted with CD44 more strongly than ligand in competition experiments. One large group of antibodies blocked ligand binding, but only with a particular cell line. This detailed analysis adds to our understanding of functional domains within CD44 and requirements for antibodies to influence recognition of one ligand.

Decreased thymidine kinase levels in peripheral blood cells from HIV-seropositive individuals: implications for zidovudine metabolism

Azidothymidine (zidovudine, AZT) used for treatment of HIV infection blocks the viral reverse transcriptase after phosphorylation by cellular enzymes. The first step in this reaction is the formation of AZT monophosphate, primarily catalyzed by host cytoplasmatic thymidine kinase (TK1). The activity of TK1 was determined in extracts of PHA-stimulated peripheral blood mononuclear cells (PBMCs) from 20 healthy volunteers and 49 HIV-infected patients at different stages of disease. In both groups we found a large intra- and interindividual variation of TK activity. Because TK1 expression is cell cycle regulated the proportion of stimulated cells was determined in the samples and the median thymidine kinase activity calculated. It was 3.0 pmol/mg/min x % S phase in the HIV-seronegative group and 1.1 pmol/mg/min x % S phase in HIV-infected individuals. The difference in thymidine kinase activity is statistically significant (p = 0.0001). The concentration of TK1 protein in the same extracts was also determined by immunoblotting. A positive correlation (r = 0.74) was observed between TK activity and amount of TK1 protein. The reason for this downregulation of TK is still unknown but may be related to the anergy observed in lymphocytes from HIV-infected persons. The reduced capacity for intracellular phosphorylation of AZT in HIV-infected individuals may be an important factor in the emergence of clinical AZT resistance and should also be accounted for in testing AZT resistance in vitro with PBMCs from healthy blood donors.

Isolation of rat heart endothelial cells and pericytes: evaluation of their role in the formation of extracellular matrix components

In order to facilitate investigation of the cells responsible for overproduction of type VI collagen in the extracellular matrix surrounding the capillaries of diabetic rat myocardium, procedures have been developed for the isolation from this tissue of endothelial cells as well as a cell type identified as pericytes. This was accomplished by enzymatic and mechanical disruption of ventricles from young rats (125 g) followed by removal of myocytes through their nonadherence to tissue culture surfaces. Endothelial cells were separated by fluorescence-activated cell sorting after staining with rhodamine-labeled acetylated low density lipoprotein and were identified by their monolayer growth pattern, reaction with anti-von Willebrand factor and the ability to form capillary-like tubes induced by low serum concentration. Pericytes were purified by selective scraping for removal of other cell types and were identified by their irregular shape, overlapping growth pattern at confluence, reaction with anti-smooth muscle actin and content of GLUT4 glucose transporter. Fibroblasts, visualized after staining with rhodamine-labeled alpha 2-macroglobulin, were only rarely detected. Analysis of collagen by immunoblotting indicated formation by both cell types of alpha 1(IV) collagen as well as the three subunits of type VI (alpha 3 at 205 kDa and alpha 1 plus alpha 2 at 150 kDa). Both endothelial cells and pericytes demonstrated transcripts for types VI, IV and I collagen, as well as fibronectin, but while the level of the mRNA for type IV collagen was higher in pericytes than in endothelial cells, the reverse was true for collagens VI and I and fibronectin. These observations suggest that both endothelial cells and pericytes contribute to formation of the myocardial capillary matrix, but that changes involving only type VI collagen, such as occur in diabetic cardiomyopathy, may reflect a response primarily of endothelial cells.

Effect of high glucose on formation of extracellular matrix components by cultured rat heart endothelial cells

In an attempt to define the basis for the microvascular changes observed in diabetic myocardium, a study was undertaken on the effect of elevated glucose on the synthesis by rat heart endothelial cells of the extracellular matrix components, types VI, IV and I collagen, as well as fibronectin. Confluent cultures of these cells, isolated by fluorescence-activated cell sorting after treatment with rhodamine-labelled acetylated low density lipoprotein, showed a three to fivefold enhancement in the synthesis of type VI collagen after exposure for 48 h to high glucose (20 to 30 mmol/l), as determined by immunoblot analysis. Increased production of type IV collagen and fibronectin was also observed, but the change was smaller and no effect on type I collagen was found. Measurement of mRNA levels by hybridization with cDNA probes indicated that 48-h exposure to high glucose significantly increased the level of transcripts for type VI and IV collagens but not for type I collagen. While glucose consumption by endothelial cells in high glucose doubled in the initial 24-h period, utilization returned to normal by 48 h, concomitant with a reduction in GLUT1 transcript levels, suggesting that signals for stimulation of collagen synthesis must be active during the initial period of exposure to elevated glucose levels.

Single-scan in vivo lactate editing with complete lipid and water suppression by selective multiple-quantum-coherence transfer (Sel-MQC) with application to tumors

A novel single-scan selective homonuclear multiple-quantum coherence-transfer technique, Sel-MQC, is presented that achieves lactate editing with complete lipid and water suppression. The method is suitable for studying tissues with high fat content and those subject to substantial motion. Frequency-selective excitation is employed to selectively prepare lactate into its multiple-quantum states; lipid and water are left in the single-quantum modes and eliminated by the multiple-quantum selection gradients. The efficiency of lipid suppression is monitored by a 2D Sel-MQC experiment which separates lipid and lactate along the multiple-quantum-evolution dimension. The spatial distribution of lactate can be imaged by the spectroscopic imaging version of Sel-MQC. Sel-MQC sequences were demonstrated both in phantoms and in vivo, using subcutaneously implanted murine EMT6 tumors.

Glucose entry into rat mesangial cells is mediated by both Na(+)-coupled and facilitative transporters

Since previous studies from our laboratory have demonstrated that increased glucose consumption by cultured rat mesangial cells is accompanied by an accelerated production of type IV and type VI collagen, we have now examined the manner by which glucose is transported into these cells. A progressive stimulation of glucose uptake by the mesangial cells was observed with increasing concentrations of NaCl so that at 145 mmol/l about twice as much glucose entered the cells as in its absence (substituted by choline chloride). Moreover, since phlorizin inhibited the NaCl-promoted uptake of glucose and this salt was found to increase the accumulation of alpha-methylglucoside in a manner which could not be duplicated by KCl or mannitol, both Na(+)-coupled and facilitative glucose transporters appeared to be present in the cells. Km values of 1.93 mmol/l and 1.36 mmol/l were determined for the co-transport and facilitated transport pathways, respectively, with their Vmax being 29.5 and 18.0 nmol.mg protein-1.h-1. Both uptake activities were found to be down-regulated by exposure of the cells to high glucose and furthermore the Na(+)-dependent transport could no longer be detected after about 12 passages of the cells. Hybridization of mesangial cell mRNA with cDNA probes revealed transcripts for the Na+/glucose co-transporter as well as GLUT1 and to a lesser extent GLUT4.(ABSTRACT TRUNCATED AT 250 WORDS)

Proton NMR observation of the antineoplastic agent Iproplatin in vivo by selective multiple quantum coherence transfer (Sel-MQC)

We have noninvasively detected the proton signal of an antineoplastic agent Iproplatin in vivo by selective multiple quantum coherence transfer (Sel-MQC). Without isotopic labeling or chemical modification, the Sel-MQC method labels Iproplatin by its intrinsic proton multiple quantum coherences and, hence, differentiates the Iproplatin signal from the intensive overlapping resonances of lipid and lactate. This proton NMR method should also be applicable to study other drugs with appropriate spin coupling patterns.

Imaging with intermolecular multiple-quantum coherences in solution nuclear magnetic resonance

A magnetic resonance imaging technique based on intermolecular multiple-quantum coherences in solution (the correlated spectroscopy revamped by asymmetric z gradient echo detection or CRAZED experiment) is described here. Correlations between spins in different molecules were detected by magnetic-field gradient pulses. In order for a correlation to yield an observable signal, the separation between the two spins must be within a narrow band that depends on the area of the gradient pulses. The separation can be tuned from less than 10 micrometers to more than 1 millimeter, a convenient range for many applications.

A new method to localize brain nuclei for surgery in extrapyramidal disease

A CT localization method to be used with the Leksell stereotactic system was employed to locate the ventral lateral nucleus of the thalamus (VL) and globus pallidus (GP) for treating extrapyramidal disease (EPD). The study comprised 100 normal adults and 70 cases of EPD, and results in both populations were compared. The 70 cases of EPD were studied ventriculography, and 30 normal adults were studied my MRI. Results indicate the accuracy of localization of the primary targets was 94.25% with the CT localization method described herein and 88.9% in the control group. In conclusion, the new CT localization method is a valuable technique to locate brain nuclei and to replace ventriculography with stereotactic surgery in the treatment of EPD patients.

Integration of linkage analyses and disease association studies

The REGD procedure of the S.A.G.E. [1994] system was used to determine the mode of inheritance of the rare disease given in Problem 1. The likelihood ratio test statistic indicated that we should reject the hypotheses of dominant and recessive inheritance at the 0.01 level, so codominant inheritance was assumed. The estimated penetrance values computed from the beta estimates given by the S.A.G.E. output were 1.0, 0.7, and 0.0 for the AA, AB, and BB genotypes respectively. A sample of three markers from each chromosome was used to determine which chromosome(s) gave evidence of having loci linked to the disease locus. The lod minus 0.83 support interval, which has been shown to provide the best approximation to 95% coverage among interval estimates [Nemesure et al., in press], was obtained for each of these markers. The criterion for rejecting the hypothesis of close linkage using the support interval methodology required that the left side of the lod minus 0.83 support interval about the maximum likelihood estimate, theta, includes only values greater than theta = 0.10. This criterion suggested that chromosomes 2, 3, and 6 did not contain the disease genes. Classical lod-score linkage analysis using the usual criteria of 3.0 for linkage and -2.0 for exclusion did not result in any regions being identified. On dropping the required lod score to 1.0, chromosomes 1, 3, and 6 gave results in favor of linkage with lod scores of 1.94 (theta = 0.19), 1.20 (theta = 0.24), and 1.30 (theta = 0.23), respectively. Association studies comparing unrelated cases to unrelated controls were done for all markers on all chromosomes. Two associations were observed which were significant at the 0.05 level after adjusting for the large number of multiple comparisons being made. The strongest association observed was between allele 7 of marker 23 on chromosome 5 and the disease (chi 2(1) = 52.20, OR = 4.7) and the second strongest was between allele 8 of marker 31 on chromosome 1 (chi 2(1) = 20.10, OR = 3.4).

Arginine-derived nitric oxide reduces fecal oocyst shedding in nude mice infected with Cryptosporidium parvum

Dietary L-arginine (4%) significantly reduced fecal oocyst shedding in athymic nude mice chronically infected with Cryptosporidium parvum. This effect appeared to be due to an increase in host nitric oxide (NO) production as it was not observed in arginine-supplemented animals administered the NO synthase inhibitor, N-nitro-L-arginine methyl ester. N-Nitro-L-arginine methyl ester alone significantly increased fecal oocyst shedding in chronically infected animals. In in vitro assays, oocyst excystation and sporozoite viability were significantly reduced by the NO donors sodium nitroprusside and S-nitroso-L-acetyl penicillamine in a concentration-dependent manner. These data suggest that arginine-derived NO may reduce the parasite load in experimental cryptosporidiosis.

Effects of resistance exercise and cycling on recovery blood pressure

The purpose of this investigation was to examine blood pressure responses during recovery from resistance exercise and cycling. Seven normotensive volunteers (5 males, 2 females) were studied. Resistance exercise consisted of three sets of five exercises (arm curl, hamstring curl, squat, 'lat pull' and bench press) on four occasions: (1) twice using 40% one-repetition maximum (1RM) for 20-25 repetitions, and (2) twice using 70% 1RM for 8-10 repetitions. The subjects also cycled for 25 min at 70% of heart rate reserve on two occasions. Measurements of recovery systolic and diastolic blood pressure were made at 2, 5, 10, 15, 30 and 60 min post-exercise with subjects in the seated position. Analysis of variance with repeated measures revealed that there were no significant differences between recovery blood pressures after the cycling or resistance exercise treatments. Average systolic blood pressure after 2 min of recovery was elevated (115 +/- 2 mmHg, P < 0.0001) and diastolic blood pressure was depressed (48 +/- 3 mmHg, P < 0.0001) in comparison to previously determined baseline values. Systolic blood pressure at 5 min and diastolic blood pressure at 15 min post-exercise were not significantly lower than resting baseline values, and remained so after 60 min of recovery. It was concluded that different intensities of resistance exercise produce the same blood pressure response in recovery and that these changes were approximately equal to those produced by cycling.

Monoclonal antibodies against the Fc fragment of IgA alpha-chain: preparation and clinical application

Fragments of the heavy alpha-chain of IgA (IgA Fc alpha) were prepared and purified from the serum of patients with heavy chain disease. It was used to immunize BALB/c mice. The immunized mouse spleen cells were then fused with myeloma cells Sp2/O. Through successive recloning of the hybridoma cell lines by the limiting dilution method, four subclonal hybridoma cells (D2, E4, F5 and G10) capable of screening IgA Fc alpha were found. Intraperitoneal transplantation of these cells induced ascites in the BALB/c mice, from which four types of monoclonal antibodies (McAb-IgA Fc alpha) were obtained. The highest McAb titer was as high as 1:16348 by the hemagglutination inhibition (HAI) test. These McAb's reacted specifically with IgA Fc alpha, but not with IgG, IgM, IgD, kappa or lambda. Serum samples from 92 normal subjects and 73 patients with various diseases were tested for Ig genetic markers by means of HAI. The family trees of three positive cases were surveyed. Results showed that the McAb-IgA Fc alpha may be used to determine the genetic marker of IgA allotypes.

Outcomes of Bordetella pertussis infection in different age groups of an immunized population

Outcomes of Bordetella pertussis infection were studied in 3 age groups (1-3, 4-6, and 7-15 years) during outbreaks in one day care center (n = 29) and in two elementary schools (n = 210). A total of 76 children were confirmed as having B. pertussis infection; 74 were confirmed by polymerase chain reaction (PCR) and 18 by culture. A positive PCR result was less common in children 1-3 years old than in those 4-6 (P = .006). Asymptomatic B. pertussis infection was more common in preschool children than in schoolchildren (P < .001), whereas schoolchildren presented with symptoms compatible with clinical pertussis more often than preschool children (60/210 vs. 3/29, P = .029). In the community of 12,691, the attack rate (laboratory-confirmed patients/100,000) was 317 in children < 4 years, 1838 in children 4-6 years, 2535 in children 7-15 years, and 248 in persons > 15 years. The protection provided by conventional pertussis vaccine is evidently rather short-lived, and booster vaccinations are needed to eradicate pertussis among schoolchildren and adults.

A physical map of the Myxococcus xanthus chromosome

A physical map of the 9.2-Mbp Myxococcus xanthus DK1622 chromosome at a resolution of 25 kbp was constructed by using a strategy that is applicable to virtually all microorganisms. Segments of the chromosome were used as hybridization probes to subdivide a yeast artificial chromosome (YAC) library into groups of linked clones. The clones were aligned by comparing their EcoRI restriction patterns. The groups of YAC clones ("contigs") were oriented and aligned with the genomic restriction map by means of common genetic and physical markers such as rare restriction sites and transposon insertions. Over 95% of the genome is represented by cloned DNA. Sixty genetic loci including > 100 genes, many of which play a role in fruiting body development, have been mapped in this way. Additional genes can now be located on the chromosome map by hybridization of their sequences to the ordered set of YAC chromosomes. The mapped genetic loci account for approximately 2% of the genome.

Antibodies to filamentous hemagglutinin of Bordetella pertussis and protection against whooping cough in schoolchildren

A pertussis outbreak was studied prospectively in an elementary school with 39 pupils. All had been immunized with at least three doses of Finnish diphtheria-tetanus toxoid-pertussis vaccine. Diagnosis of pertussis was based on culture, polymerase chain reaction results, and EIA serology using filamentous hemagglutinin (FHA), pertussis toxin, and 69-kDa outer membrane protein as antigens. At the first sampling, 21 children had symptoms suggestive of pertussis, and 18 were healthy. Of the latter, 8 remained healthy without any antibiotic treatment and 9 developed clinical pertussis 1-22 days later. One child developed cough later, but this symptom did not meet criteria for pertussis. The mean levels of IgG, IgM, and IgA antibodies to FHA were significantly higher in 8 healthy children than in 9 children who developed pertussis after the first sampling (P < .001, P = .027, and P = .011, respectively). The results show that antibodies to FHA of Bordetella pertussis in immunized schoolchildren correlate with protection against pertussis.

Gene expression of transforming growth factor beta 1 and extracellular matrix proteins in murine Schistosoma mansoni infection

BACKGROUND/AIMS

The study of Schistosoma-induced hepatic fibrosis in murine Schistosoma mansoni infection has elucidated the nature of hepatic fibrosis in humans. In the present study, fibrogenic gene expression was determined in murine S. mansoni infection during primary infection, after chemotherapy with praziquantel, and during secondary infection.

METHODS

Both histomorphometric analysis and Northern blot profiles were performed.

RESULTS

Histomorphometric analysis of granulomatous inflammation showed smaller hepatic fibrotic granulomata after chemotherapy and during secondary infection. Albumin gene expression remained relatively constant throughout primary infection, chemotherapy, and secondary infection. Fibronectin gene expression in primary infection was comparable with the level observed in noninfected mice and was reduced by chemotherapy. Reinfection resulted in augmented expression levels equal to primary infection levels. Osteonectin gene expression was active in primary infection, was reduced by chemotherapy, and was actively reexpressed in secondary infection. Interstitial matrix macromolecules, types I and III collagen, and basement membrane collagen showed high levels of gene expression in primary infection, were virtually terminated by chemotherapy, and were reexpressed on reinfection. The gene expression of transforming growth factor beta 1, a major, fibrogenic cytokine, paralleled collagen expression.

CONCLUSIONS

Chemotherapy of schistosomiasis initiated a dramatic decrease in steady-state messenger RNA levels of major proteins associated with fibrosis; reinfection resulted in a reexpression of these genes.

Prediction of the oxygen cost of the deadlift exercise

The purpose of this study was to examine the relationship between total estimated work, bar load and total oxygen consumption (TVO2) during the deadlift exercise. Forty-two observations of TVO2 during a wide range of deadlifting bouts were made on a heterogeneous sample of 10 males and 14 females. TVO2 was measured by standard open-circuit spirometry. An R of 0.912 for work and TVO2 indicated that total estimated work during deadlifting can be used to predict oxygen cost accurately. The calculated regression equation was TVO2 (litres of O2) = 2.63 + 0.80 work (kJ) with a S.E.E. of 1.50 litres O2. An R of 0.909 for bar load and TVO2 indicated essentially the same predictability using bar load as the independent variable. The calculated regression equation was TVO2 (litres O2) = 2.88 + 0.005 bar load (kg) with a S.E.E. of 1.5 litres O2. Care should be taken when converting oxygen cost to energy expenditure values using non-protein R equivalents, since underestimations are likely, due to the heavy glycolytic involvement.

Typing of group A streptococci by random amplified polymorphic DNA analysis

Random amplified polymorphic DNA (RAPD) analysis was evaluated in comparison with restriction endonuclease analysis (REA) of genomic DNA and serotyping in the typing of 160 epidemiologically unrelated group A streptococci (GAS). Amplification of genomic DNA of GAS was performed with a single primer with an arbitrarily selected nucleotide sequence of 12 nucleotides. In total, 31 RAPD patterns and 15 REA patterns were observed among the isolates studied. The results of RAPD analysis were in accordance with the results of REA for 86% of the isolates, as both methods identified 15 different strains among 138 isolates. However, RAPD analysis differentiated 16 additional strains among 22 isolates. RAPD analysis was somewhat better than REA for differentiation of isolates of the same and different serotypes. However, not all of the serotypes were differentiated by RAPD analysis either. In conclusion, RAPD analysis provides a practical alternative for genomic typing of GAS. It can be recommended for the typing of GAS, especially if used in parallel with serotyping.

[Villous tumor of the duodenum]

8 cases of duodenal villous tumor were reported. A total of 11 tumors, with 2 in the bulb and 9 in the descending part, were excised. Malignant change was found in 4 cases (50%). Diagnosis could be made by using hypotonic duodenography and fibroscopy. The integral tumor should be examined by frozen section during operation, so as to determining the appropriate operation for satisfactory result. Postoperative follow up should be done periodically because of the possibility of recurrence after local excision.

Primers are decisive for sensitivity of PCR

A sufficient sensitivity of PCR is a prerequisite for its use in the diagnosis of infectious diseases. We have used PCR for detecting gene elements of Borrelia burgdorferi, mycobacteria and Bordetella pertussis. With all these microbe groups, difficulties were encountered in achieving the demanded sensitivity with the primer pairs primarily selected. An extensive testing of various reaction parameters did not improve the sensitivity. Subsequently, we synthesized more primers derived from slightly different positions of the original target sequences. When the original and new primers were tested in possible combinations, some primer pairs reached 100-fold to 1000-fold higher sensitivity than the primary pairs. We conclude that in optimizing the sensitivity of PCR, more emphasis should be put on testing of several primer pairs than on the extensive screening of reaction parameters. Thus far, a trial-and-error approach has to be used, because there is no means to predict the sensitivity properties of a selected primer pair.

[Mapping of face and extremity skin cleavage lines in Chinese adult cadavers]

On fresh Chinese adult cadavers, which were obtained within 6 hours of sudden death, multiple skin holes of 1 cm apart were made with a conical steel punch of a diameter of 5 mm. Chinese ink was dipped into the wounds, which presently appeared to be rhomboid slits. Mapping of the directions of these rhomboid slits gave rise to cleavage lines of that area. This paper presents the skin cleavage lines of the face and extremities in Chinese adult cadavers.

[Fast neutron treatment of osteosarcoma]

Twelve patients with advanced osteosarcoma were treated with fast neutron at the Neutron Therapy Facility, the Hight-Energy Physics Institute, Chinese Academy of Science. Of the 12 patients, 5 were operated after radiotherapy. Three of them received fast neutron alone, and the other 2 with added 60Co. The doses ranged from 660 NcGy to 2 168 NcGy. Pain was relieved and the tumor size decreased in all the treated patients. Only one case was found histologically free of viable tumor cells. Skin reaction was serious and the knee joint function was impaired in all patients.

[Study on urine ALb, serum and urine beta 2-m, IgG, and THP]

The urine ALb, serum and urine beta 2-m, IgG, and THP were serially determined with radioimmunoassay to assess the renal functions during various stages of burn in 52 patients with TBSA over 30% (mean +/- s 58.4% +/- 18.88%). It was found that the urine levels of ALb, IgG, and THP and the serum and urine levels of beta 2-m were remarkably increased and that the serum levels of IgG were decreased after burns. Our study suggested that the measurements of urine ALb, serum and urine beta 2-m, IgG, and THP using radioimmunoassay were sensitive in assessing renal glomerular permeability and tubular functions after burn. It is presumed that such methods might be used to help identify the location, the extent, and the severity of the renal abnormalities and provide valuable information about the differential diagnosis and the prognosis of the renal damage in patients with extensive burns.

Effects of thermocyclers and primers on the reproducibility of banding patterns in randomly amplified polymorphic DNA analysis

The effects of thermocyclers and primers on the reproducibility of banding patterns in randomly amplified polymorphic DNA analysis were tested. Purified Bordetella pertussis DNA was analysed with four primers (12-mer), which did not differ from each other in their GC-content. Three different thermocycler models from two manufacturers were tested. Three of the primers produced consistent banding patterns in separate wells of the reaction plates of individual thermocyclers, and in different thermocycler models. In contrast, the fourth primer showed extensive between-instrument variation, and the within-instrument variation with this primer was acceptable only when the most advanced thermocycler model was used. We conclude that only primers that provide consistent banding patterns in different environments should be chosen for interlaboratory use in randomly amplified polymorphic DNA analysis. The primers showing variability in banding patterns can only be used if they produce consistent results in the thermocycler used.

[Studies on the relationship between HPV and respiratory tract tumors. I. Correlation between HPV and laryngeal carcinoma]

In this paper, alpha-32P-dCTP-labeled HPV-11 and HPV-16 DNA were used as probe, and slot and Southern blot hybridization techniques were used to detect HPV-11 and HPV-16 DNA related sequences in 37 laryngeal carcinoma tissues taken from patients in Qingdao and Beijing. Using the slot blot technique, 86% (32/37) of the cases showed positive hybridization with HPV-11 probe, while 81% (30/37) showed positive results with HPV-16. Another 81% (30/37) showed positive hybridization with HPV-11 and HPV-16 simultaneously. Using Southern blot hybridization Pst digestion, the hybridization pattern corresponded to that of HPV-16 in 46; (13/28), and none corresponded to HPV-11. The results suggest that HPV-16 may induce laryngeal carcinoma.

Putative anticryptosporidial agents tested with an immunodeficient mouse model

Lasalocid, sinefungin, and dehydroepiandrosterone were tested for anticryptosporidial activity with an immunodeficient mouse model at doses that have been reported effective when tested with immunosuppressed rodent models. Small but significant reductions in oocyst excretion were only observed under some conditions with lasalocid and dehydroepiandrosterone, but sinefungin had no effect.

[Repair of soft tissue defects of hand with pudendo-femoral skin flaps]

Soft tissue defects of the hand have been repaired with free pudendo-femoral skin flaps in 13 patients. The results are quite satisfactory in all cases. The flaps are thin with little fat to interfere with post-operative appearance. The donor sites are well-hidden and can be primarily closed with no functional disturbances. Hence the ideal donor site for soft tissue defects of the hand.

Sensitive and specific polymerase chain reaction assays for detection of Bordetella pertussis in nasopharyngeal specimens

Polymerase chain reaction (PCR) assays that amplify segments of a repeated gene element and a toxin promoter gene of Bordetella pertussis were compared with a culture established for the diagnosis of pertussis. Of 44 nasopharyngeal (NP) aspirates collected during a pertussis outbreak, repeated gene element PCR showed a positive result in 21 (48%), including all three patients with positive culture results. Results of toxin promoter gene PCR were positive in eight (18%) cases, and the pathogen was not detected in one patient with a positive culture result. A more sensitive nested PCR assay, based on repeated gene element PCR, was then developed. During a second outbreak two different transportation systems were tested in 146 duplicate NP swabs. Transportation of swabs in empty tubes proved to be better than in transport media for PCR. A total of 190 NP specimens from the two outbreaks were tested, and in 56 the results were shown to be positive by PCR, including all 16 cases confirmed as positive by culture. We conclude that the PCR assay is more sensitive than culture in the diagnosis of pertussis; NP swabbing is a simple, practical, and reliable method of collecting clinical specimens for PCR assays and cultures.

[Chondrolaryngoplasty]

We have successfully performed chondrolaryngoplasty in 6 cases. The results are satisfactory. Of the patients, five have previously undergone male to female transsexual operation and one with pseudohermaphroditism. Chondrolaryngoplasty is performed under local anesthesia. The amount of excised thyroid cartilage is 2.0 to 2.4 cm in length and 0.6 to 1.2 cm in width on each side. In 3 cases, mild hoarseness is observed postoperatively and it is very transient, lasting less than 20 days. This paper introduces the applied anatomy, operative technique and key points for a successful chondrolaryngoplasty.

Inhibition of the spore polar filament extrusion of the microsporidium, Encephalitozoon hellem, isolated from an AIDS patient

Spores of the microsporidian parasitic protozoan Encephalitozoon hellem were purified and incubated at 37 degrees C in a solution with an electrolyte composition similar to that of mammalian extracellular fluid, and in solution in which the calcium had been replaced with 0.2 mM EGTA. Polar filament extrusion (germination) was monitored by both scanning electron microscopy and light microscopy. Germination was pH-dependent, with optima at pH 7.4 and 9.5, and was significantly greater in the presence of medium calcium. Hydrogen peroxide caused a concentration-dependent increase in germination that was also reduced in a calcium-free medium. Four agents were found to inhibit spontaneous and H2O2-stimulated polar filament extrusion: the microfilament disrupter, cytochalasin D; the microtubule disrupter, demecolcine; the calcium channel blocker, nifedipine; and the antifungal agent, itraconazole. These results are consistent with the existence of a calcium-channel-mediated step, and requirements for an F-actin- and for a tubulin-containing element in the germination process of the spore of this parasite. Nifedipine, cytochalasin D and itraconazole all have different sites of action and were therefore able to potentiate one another when used in paired combination to inhibit germination.

Possible network interactions indicated by bilaterally coherent fast rhythms in expiratory recurrent laryngeal nerve discharges

1. In a search for correlated fast rhythms in recurrent laryngeal (RL) expiratory (E) activities, we performed spectral and coherence analysis on bilateral RL nerve discharges in 54 midcollicular decerebrate, paralyzed cats. 2. Inspiratory (I) RL activities showed in almost all cases high-frequency oscillations (HFO, range 50-100 Hz) that were bilaterally coherent and also coherent to HFOs in phrenic (PHR) activities. In contrast, bilaterally coherent rhythms (range 24-54 Hz) in RLE discharges were found in only a fraction of the cats (6/54); in the other cats (48/54) such coherences were absent even though the auto-spectra showed the presence of similar fast rhythms on the two sides. The bilateral RLE coherences were associated with increased amplitude and prolonged duration of RLE activity, such as occurred following removal of phasic pulmonary stretch receptor inputs by vagotomy or by no-inflation. 3. Thus, although coherent fast rhythms are uncommon in RLE discharges, their occurrence under some conditions indicates the presence of short-time-scale interactions between neurons involved in this activity. This suggests that such rhythms are a general feature of neural networks.

Hepatic fibrosis and gene expression changes induced by praziquantel treatment during immune modulation of Schistosoma japonicum infection

In the present study fibrogenic gene expression was determined in murine Schistosoma japonicum infection during the progression of immune modulation of infection and following chemotherapy during the course of immune modulation. Histomorphometric analysis of granuloma size and collagen deposition revealed peak granuloma size in acute infection (5 weeks) and peak hepatic collagen content at 16 weeks of infection. Peak Type I collagen gene expression was concomitant with TGF-beta 1 gene expression at 8-11 weeks. Chemotherapy during either acute (9 weeks) or chronic (24, 28 weeks) infection resulted in increased collagen deposition and increased gene expression of Type I collagen and TGF-beta 1. However, chemotherapy at 14-16 weeks resulted in decreased levels of TGF-beta 1 gene expression and essentially minimal change in Type I collagen deposition and gene expression. These data indicate that chemotherapy of schistosomiasis japonica does not reverse hepatic fibrogenesis when administered in acute infection-when granuloma size is maximal-or in chronic infection. However, a beneficial effect on hepatic fibrogenesis is seen when chemotherapy is administered at 14-16 weeks post-infection, a time of decreasing granuloma size and maximal hepatic collagen content. Thus the ability to reverse schistosomal-induced hepatic fibrogenesis by chemotherapy may depend on disease stage.

Effects of protein malnutrition on experimental giardiasis in the Mongolian gerbil

To determine the effects of protein malnutrition on the severity and duration of infection with Giardia lamblia, Mongolian gerbils were pair-fed a pelleted control (C) diet (20% protein) and a low-protein (5%; LP) diet for 3 weeks before and after being infected with 100,000 cysts orally. Weight loss, fecal fat, enteropooling, and the duration of cyst excretion were all greater in the infected LP than in the infected C animals. During peak infection the upper intestinal intraepithelial lymphocyte infiltration, crypt enlargement, and villus enterocyte migration were greater in C than in LP animals, as was the villus mast cell number at the end of the infection. It is concluded that in the protein-malnourished host the increased severity of Giardia infection correlates with a reduction in enterocyte production and migration, probably secondary to a reduced lymphocyte infiltration, and the increased infection duration correlates with blunted mast cell migration into affected villi.

Evaluation of pooled and individual components of Bordetella pertussis as antigens in an enzyme immunoassay for diagnosis of pertussis

Six different antigen preparations for use in an enzyme immunoassay (EIA) to detect IgM, IgA and IgG antibodies to Bordetella pertussis were evaluated using sera from 13 randomly selected culture-positive patients and from 87 patients with suspected pertussis during a pertussis outbreak. Based on results in 80 healthy control sera a specificity limit of 99.9% was selected. Sera from all culture-positive patients reacted with at least one of the antigens. The sensitivity of the EIA using the individual antigen preparations was 85% for filamentous hemagglutinin, 92% for pertussis toxin, 62% for 69 kDa outer membrane protein, 85% for a pool of these three antigens, 54% for sonicated whole bacteria and 69% for 21 kDa pertussis toxin subunit S1. In the outbreak patient group 49 (56%) of the initial sera reacted with at least one of five antigen preparations. The EIA using sonicated bacteria detected only 41% of all seropositive cases compared with 51% using filamentous hemagglutinin, 61% using pertussis toxin, 65% using 69 kDa OMP and 65% using pooled antigen. It is concluded that either the pooled antigen or pertussis toxin antigen are suitable antigen preparations for use in the EIA for diagnosis of pertussis.

Comparison of polymerase chain reaction with culture and enzyme immunoassay for diagnosis of pertussis

A polymerase chain reaction (PCR) assay amplifying a segment of a repeated gene element of Bordetella pertussis was compared with culture and enzyme immunoassay (EIA) for the diagnosis of pertussis. The PCR assay was specific for B. pertussis in tests with a panel of other bacteria and with an extensive collection of specimen material from healthy persons and children with respiratory infections other than pertussis. The PCR assay was used in the analysis of 117 nasopharyngeal swabs collected from children at an elementary school at which a pertussis outbreak occurred. Fifty-six (48%) of the 117 swabs were positive, including those for all six culture-positive cases. The PCR method was then applied to analyze another pertussis outbreak. Of 40 nasopharyngeal aspirates taken from 37 clinically susceptible pertussis patients and from three asymptomatic contacts, the PCR identified 18 (45%), including all 3 culture-positive and 5 (35%) of the 14 seropositive patients. The most consistent and reliable diagnosis by positive PCR result was observed with those patients experiencing symptoms within 1 to 6 weeks of sample collection. We conclude that PCR is a rapid, sensitive, and specific means of diagnosing pertussis, especially during the first weeks of disease. The assay can be performed with both nasopharyngeal swabs and aspirates.