Success rates and cost-effectiveness of antibiotic combinations for initial treatment of central-venous-line infections during total parenteral nutrition

BACKGROUND

Central-venous-line infections can be successfully treated with appropriate antibiotics, thus avoiding the need for catheter removal. Based on our experience, vancomycin, gentamicin, piperacillin, ceftazidime, and amphotericin, alone or in combination, are usually administered, pending sensitivity results. This empirical list, however, has never been verified against actual sensitivity results nor has it been tested for cost or efficacy.

METHODS

Medical records of inpatients on hyperalimentation over 1 year were reviewed. Success rate, therapy duration, and drug acquisition cost and charge were assessed for central-venous-line infections. Antibiotics then were paired and evaluated in terms of charge and efficacy against all microorganisms as determined by sensitivity results.

RESULTS

In 500 inpatients receiving hyperalimentation for 9,698 patient-days, 8.4 central-venous-line infections/1,000 patient-days occurred. Staphylococcus non-aureus, Candida species, Enterococcus faecium, and Staphylococcus aureus predominantly were isolated. Of the infections, 51 (67%) were sensitive to one or more of the initial antibiotics. A 2-week course of antibiotics successfully treated 50 (66%) catheter infections without line removal. Appropriate initial therapy on average reduced treatment duration by 8 to 10 days and drug charges by $400 to $700.

CONCLUSIONS

Amikacin-vancomycin appears to be the most cost-effective selection for presumed central-venous-line infections, pending sensitivity results, followed by valid alternatives. Lower failure rates are well worth the extra cost in pharmaceutical charges.

Effects of acupuncture on the pituitary-thyroid axis in rabbits with fracture

PURPOSE

To observe the effects of acupuncture on the pituitary-thyroid axis in rabbits with fracture.

METHOD

36 male rabbits with a 3-mm width experimental defect in the middle segment of the left radius were randomly divided into the treatment group and control group, and the changes in serum T3, T4 and TSH contents in different weeks were investigated.

RESULTS

Serum T3, T4 and TSH contents in the treatment group all were higher than those in the control group, with statistically significant differences in the contents of T4 and TSH in the second week and T3 content in the fourth week (P < 0.01 or P < 0.05).

CONCLUSION

The action of promoting union of fracture is possibly related with the pituitary-thyroid axis.

[Ultrastructural characteristics of epiretinal membranes]

OBJECTIVE

To investigate ultrastructural features and the correlation between the cell activation and extracellular matrix (ECM) expression of epiretinal membranes.

METHODS

Immuno-electron-microscopy was done on the epiretinal membranes removed by vitrectomy from 16 patients with rhegmatogenous retinal detachment associated with proliferative vitreoretinopathy (PVR). The specimens were stained with antibodies to ECM proteins, including type I collagen, type III collagen and fibronectin (FN).

RESULTS

A type of cells with a number of lamellipodia was found in membrane sections of 9 patients. The lamellipodia appeared to be either coiled or branched and were surrounded by abundant collagen fibers of type I and III. The cells with lamellipodia varied in their phenotypes and with or without pigment. There were dense gold particles of FN in contact regions of lamellipodia and collagen.

CONCLUSIONS

Our observations support that the contraction of epiretinal membranes is the result of an interaction between cells and collagen, and the cells extending lamellipodia may initiate contractile events. FN is responsible for this contractile action.

[Dynamic changes in hepatic myofibroblast of rabbits with Schistosoma japonicum]

OBJECTIVE

To observe the dynamic changes in hepatic myofibroblasts during the formation of schistosomal hepatic fibrosis and to investigate the pathogenesis of hepatic fibrosis.

METHODS

Each rabbit was infected with 80 +/- 1 S japonicum. Liver biopsies were done at different time point after infection and the samples were embedded with paraffin and stained with HE and picric acid-sirius red. The dynamic changes in the areas of granuloma were observed, and the extent of liver fibrosis and the expression of alpha-SMA positive cells were semiquantitated. At the 16th week after infection, the rabbits with S. japonicum were received IFN-gamma after treatment of praziquantel and contrasted with the saline group.

RESULTS

The granuloma appeared at the 6th week after infection and its areas reached the biggest at the 8th week. Then the granuloma shrinked gradually, but the extent of liver fibrosis aggravated progressively. The alpha-SMA positive cells were observed at the 4th week after infection and their number enhanced gradually. The extent of liver and the expression of alpha-SMA positive cells were significantly different between each treated group, and the IFN-gamma treated group showed the best result.

CONCLUSION

The myofibroblasts play an essential role in the formation and development of schistosomal hepatic fibrosis.

Plasma L-5-oxoproline carbon and nitrogen kinetics in healthy young adults

L-5-oxoproline (OP), an intermediate of the gamma-glutamyl cycle of glutathione synthesis and degradation, may serve as a probe for the state of glutathione kinetics. We explored the whole-body carbon and nitrogen kinetics of OP in five male healthy subjects (75.2 kg; 181 cm; 26 y) after a 5-d adaptation to an adequate L-amino acid-based diet (160 mg N x kg(-1) x d(-1); 188 kJ x kg(-1) x d(-1)), using a crossover design. On day 6 of the diet period, we carried out an 8-h tracer protocol (3 h fast; 5 h fed; 2/3 of daily nitrogen intake) with intravenous infusion of L-[1-(13)C]oxoproline and L-[3, 3-(2)H]cysteine or, in randomized order, on the second occasion, L-[(15)N]oxoproline and L-[3,3-(2)H]cysteine. Plasma OP was isolated by cation exchange and after addition of internal standards (DL-[(2)H(3)]-5-oxoproline; L-[(15)N, U-(13)C(5)]-5-oxoproline; DL-[(2)H(3)]-glutamic acid) derivatized to form TBDMS esters and measured by gas chromatography/mass spectrometry. Plasma OP concentration did not differ between fed and fasted state (fast: 59. 4 +/- 8.3; fed 59.2 +/- 8.9 nmol/mL). (13)C- and (15)N OP flux during the fasted and fed state were 19 +/- 3.6, 21.2 +/- 3.2, and 22.6 +/- 3.9, 25.8 +/- 4.3 micromol x kg(-1) x 30 min(-1), respectively. OP oxidation was 15.6 +/- 3.6 and 17.9 +/- 3.5 micromol x kg(-1) x 30 min(-1), in fasting and feeding, respectively, (P < 0.05). More than 80% of the plasma flux was oxidized. These findings are compared with the published literature on GSH turnover in plasma of human subjects and underscore the need to define more completely the dynamic aspects of glutathione metabolism and of the intermediates of the gamma-glutamyl cycle.

Optical tomographic image reconstruction from ultrafast time-sliced transmission measurements

Optical imaging and localization of objects inside a highly scattering medium, such as a tumor in the breast, is a challenging problem with many practical applications. Conventional imaging methods generally provide only two-dimensional (2-D) images of limited spatial resolution with little diagnostic ability. Here we present an inversion algorithm that uses time-resolved transillumination measurements in the form of a sequence of picosecond-duration intensity patterns of transmitted ultrashort light pulses to reconstruct three-dimensional (3-D) images of an absorbing object located inside a slab of a highly scattering medium. The experimental arrangement used a 3-mm-diameter collimated beam of 800-nm, 150-fs, 1-kHz repetition rate light pulses from a Ti:sapphire laser and amplifier system to illuminate one side of the slab sample. An ultrafast gated intensified camera system that provides a minimum FWHM gate width of 80 ps recorded the 2-D intensity patterns of the light transmitted through the opposite side of the slab. The gate position was varied in steps of 100 ps over a 5-ns range to obtain a sequence of 2-D transmitted light intensity patterns of both less-scattered and multiple-scattered light for image reconstruction. The inversion algorithm is based on the diffusion approximation of the radiative transfer theory for photon transport in a turbid medium. It uses a Green s function perturbative approach under the Rytov approximation and combines a 2-D matrix inversion with a one-dimensional Fourier-transform inversion to achieve speedy 3-D image reconstruction. In addition to the lateral position, the method provides information about the axial position of the object as well, whereas the 2-D reconstruction methods yield only lateral position.

[Light puncture combined with longhu xingnao granules in treating acute traumatic intracranial hematoma]

OBJECTIVE

To confirm the clinical therapeutic effectiveness of Longhu Xingnao Granule (LHXNG) medicated after light puncture in treating acute traumatic intracranial hematoma.

METHODS

Patients were randomly divided into two groups, 30 patients of the tested group were treated with LHXNG after light puncture and 20 patients of the control group treated with western medicine alone.

RESULTS

The effect of the tested group was evidently superior to the control group (P < 0.05) and with a markedly shortened resuscitation time (P < 0.05).

CONCLUSION

LHXNG has the function of promoting blood circulation and arresting bleeding, and improving resuscitation. In coordination with light puncture, it could improve the living quality of patients, shorten the resuscitation and treatment time, so as to reduce the maim and death rate.

Evaluation of a suture electrode for direct bladder stimulation in a lower motor neuron lesioned animal model

The purpose of this study was to evaluate a "suture" type electrode for direct bladder stimulation in an animal model of a lower motor neuron lesion. During an initial surgery, five male cats were instrumented under anesthesia using multistranded, 316 LVM, stainless-steel, wire electrodes implanted on the bladder wall serosa above the trigone area. Electrodes were constructed with a needle attached to the end that was removed after suturing the electrode in place. Additional instrumentation included urinary bladder catheters (tubes) for pressure recording and filling, and hook type electrodes for leg and pelvic floor electromyography recording. Chronic bladder filling and stimulation studies were conducted in tethered animals three to four weeks following surgery. To test these electrodes in a spinal cord injury model, a lower motor neuron lesion was performed including the sacral cord and complete nerve roots at L6 and below. These animals were evaluated during weeks 3 and 10 after injury. Direct bladder stimulation induced active contractions and voiding both before and after spinal cord injury. Effective stimulation parameters consisted of 40 pulses per s, 300 micros to 1 ms pulse duration, a stimulation period from 3 to 4 s, and a stimulation current from 10 to 40 mA. Fluoroscopy revealed an open membranous urethra during stimulation and following stimulation. A small diameter penile urethra was observed to limit flow. Postmortem evaluation of the suture electrode revealed no abnormalities such as corrosion, migration into the bladder lumen or displacement. These findings indicate that suture electrodes are suitable and effective for short-term implantation in the lower motor neuron animal model.

Localization of metabotropic glutamate receptors mGluR1alpha and mGluR2/3 in the cat retina

The distribution of metabotropic glutamate receptors 1alpha (mGluR1alpha) and mGluR2/3 in the cat retina was studied through the use of preembedding immunocytochemistry for light and electron microscopy. Staining for mGluR1alpha in the outer plexiform layer was seen in numerous punctate structures that were identified as rod spherules. Cone pedicles remained unlabeled. A number of amacrine and ganglion cell somata also were stained with processes ramifying throughout the inner plexiform layer. These processes were postsynaptic to cone bipolar cells in both sublaminae, where they comprised one but not both of the postsynaptic elements at dyad contacts. Immunostaining for mGluR2/3 was observed in horizontal cells as well as in numerous amacrine and displaced amacrine cells. Labeled amacrine processes were postsynaptic to cone bipolar cells in both sublaminae but, similar to mGluR1alpha, comprised only one of the postsynaptic elements. Staining for mGluR2/3 also was seen in amacrine processes postsynaptic to rod bipolar terminals; these processes were identified as belonging to type A17 amacrine cells. The distribution patterns indicate that both mGluR1alpha and mGluR2/3 are positioned for postsynaptic function, whereas mGluR1alpha also may contribute to the presynaptic regulation of glutamate release from rod photoreceptors.

[Neuroendocrine mechanisms of impact by experimental stress on plasma glucose level in STZ KM mice]

OBJECTIVE

To explore the neuroendocrine mechanisms of effects by experimental stress on plasma glucose level in streptozotocin induced mice(STZ mice).

METHODS

Forty STZ mice were divided randomly into Group A (STZ mice, stress) and Group B (STZ mice, no stress), and 20 normal KM mice in Group C (normal mice, stress) and Group D (normal mice, no stress). Group A and Group C were exposed to multiple stressors (restrain, rotation, crowding) for 6 weeks. Before and after the experiment, blood glucose(BG) levels were measured. By the end of experiment, blood and hypothalamus samples were collected to measure plasma insulin(I) concentrations, insulin sensitivity index(ISI), plasma norepinphine(NE), epinphin(EPI) and beta endorphin(beta-EP) concentrations.

RESULTS

After stress, the BG levels significantly increased and I concentrations decreased in Group A. Group A showed a greater decrease of ISI than that in Group B. There was significant difference in plasma NE and EPI concentrations among groups, and Group A showed marked increase. There was no significant difference in beta-EP concentrations among groups. There were low to moderate correlations among these variables after stress.

CONCLUSION

The STZ mice likely have altered adrenergic sensitivity to stress, which might play a leading role in the neuroendocrine mechanism of hyperglycemia of STZ mice after stress. The beta-EP might participate in this process of regulating glucose metabolism.

[Identification of beta-FBG-455G/A polymorphisms in 210 samples of Guangdong population and the relationship with plasma fibrinogen level]

OBJECTIVE

To analyze the frequency of beta-fibrinogen (beta-FBG) gene G/A-455 polymorphisms in Guangdong Chinese population and the relationship between genotype and plasma fibrinogen levels.

METHODS

DNA of 210 samples were analyzed by using PCR-RFLP. Turbidimetric method for the levels of plasma fibrinogen was performed in 92 samples.

RESULTS

The frequency of beta-FBG G/A-455 genotype A/A was 0.038; G/G was 0.514 and G/A was 0.448. The frequency of the A-allele was 0.262. The average plasma fibrinogen level in 46 samples of genotype G/A was (2.18 +/- 0.24) g/L and in 42 samples of G/G genotype was (2.03 +/- 0.25) g/L. There was significant difference between genotype and plasma fibrinogen (P < 0.01).

CONCLUSION

The frequency of beta-FBG G/A-455 A-allele in Guangdong Chinese population is higher than that in European. The plasma fibrinogen level in G/A genotype is higher than that in G/G genotype. It suggested that the beta-FBG gene expression might be associated with the genotype.

[Studies on data compression of 1-D NMR spectra using wavelet transform]

The multiresolution signal decomposition (MRSD) algorithm based on wavelet transform was applied to the compression of 1-D NMR spectra. A NMR spectrum which was composed of 32768 data points was investigated and the spectrum can be completely reconstructed with the residual square deviation (RSD) being as small as 2.7769 x 10(-4) when the spectrum was compressed to 512 data points. The relationship among the RSD and the different wavelet function, number of decomposiion and the compression ratio was also discussed.

Synovial T cell receptor heterogeneity in early arthritis

Rheumatoid arthritis (RA) has been postulated to result from a synovial immune response to an unidentified antigen(s), which should be mirrored by the T cell response. Here we investigate the T cell receptor (TCR) repertoire in the synovial tissue of patients with arthritis of early to moderate duration. We developed a nested polymerase chain reaction (PCR) technique to examine the TCR repertoire of small biopsy specimens, and show that the method is highly sensitive. We apply this technique to synovial biopsies obtained from the knee joints of patients with early to moderate duration arthritis (average duration of arthritis 1 year, range 0. 02-2.75 years). We examined biopsies from 5 normal individuals, 32 RA patients, 7 patients with seronegative spondyloarthropathy (Sp), and 12 patients with undifferentiated arthritis (UA). TCR message was detectable in 4/5 normals, 15/32 RA, 5/7 Sp, and 8/11 UA biopsies, with sampling error likely accounting for most negative biopsies. The average numbers of TCR Vbetas detected per TCR-positive biopsy were 5.0 +/- 3.7 for normals, 12.7 +/- 8.4 for RA, 18.0 +/- 7.4 for Sp patients, and 14.4 +/- 10.2 for UA. Examination of TCR messages by single-stranded conformational polymorphism analysis showed similar proportions of dominant clones in the normals compared with the patients with inflammatory arthritis. Sequence analysis was performed on 33 dominant clones from 16 patients. Sequence alignment of the third hypervariable regions showed some evidence of disease-specific sequence clustering for Sp, while some RA sequences showed similarity to previously described motifs. These data indicate greater TCR heterogeneity in early Sp and UA compared with normal synovium. Disease-specific TCR sequences may occur in early RA and Sp.

[Construction of full-length cDNA clone and complete nucleotide sequence of RNA2 of cucumber mosaic virus SD strain]

The full-length cDNA clone of CMV-SD RNA2 was constructed from two cDNA clones, which were obtained by RT-PCR with primers synthesized based on terminal sequences determined using 5' RACE and 3' RACE, respectively; and the complete sequence was determined. It consists of 3048 nt and there are two partial overlapped ORFs. ORF1, which is located in the 5' portion (79-2652 nt), codes for 2a protein of 858aa, and GDD consensus sequence reported to be "polymerase site" was found in deduced 2a protein sequence. ORF2, which is located in the 3' portion (2414-2746 nt), codes for 2b protein of 111aa. The overall nucleotide sequence homologies with RNA2 of CMV Fny and Q strain, which are representatives of subgroups I and II, respectively, are 91.7% and 75.6%; the amino acid sequence homologies are 93.8% and 67.7% for 2a protein, and 83.0% and 51.3% for 2b protein, respectively. These results demonstrated that CMV-SD belongs to subgroup I.

Preparation of GFLV CP-gene cDNA probe labeled by photosensitive biotin and its application in detection of GFLV

The cDNA of the GFLV CP gene amplified from clone pGAB5 by PCR was labeled by photosensitive biotin. The probe sensitivity is 5 pg, and the detectable amount of unlabeled GFLV cDNA was 10 pg by Dot-blot hybridization when the biotin-labeled cDNA was used as a probe. The results of detection for GFLV by probe have positive correlation with those of ELISA. The minimum amount of grapevine tissue for detection by probe was 100 times lower than that by ELISA. The seasons and the position of grapevine leaves do not limit application of this method.

Photolysis of phloxine B in water and aqueous solutions

Phloxine B (2',4',5',7'-tetrabromo-4,5,6,7-tetrachlorofluorescein disodium salt) as a potential photoactive insecticide was rapidly photodegraded in water under various light sources. Two major photolytic products characterized were 2',4',5'-tribromo-4,5,6, 7-tetrachlorofluorescein and 4',5'-dibromo-4,5,6, 7-tetrachlorofluorescein. The photolysis rates of phloxine B were influenced by various factors including salts in medium, sample pH, and light sources. Half-lives (t(1/2)) of phloxine B spiked in different water samples and 2% NaCl solution at 29 +/- 1 degreesC ranged from 0.70 to 1.28, 26.3 to 115, and 14.1 to 46.2 hours under 254 nm, 365 nm, and cool white fluorescent lights, respectively. Half-lives of phloxine B in tap, stream, or seawater in a beaker were from 10 to 13 min under sunlight at ambient air temperature. In a range of buffer pH 6-8 at 29 +/- 1 degreesC, phloxine B photodegraded slightly faster in acidic solution than in basic solution. The photolysis t(1/2) of phloxine B at 29 +/- 1 degreesC was 25, 32, 128, and 755 min in the buffered NaF, NaCl, NaBr, and NaI solutions, respectively. The t(1/2) of phloxine B was 31 min when phloxine B was dissolved in the sodium phosphate buffer as control. Sodium iodide and ammonium iodide photostabilized phloxine B 24 and 27 folds, respectively, when it was compared with the buffer control.

Increased secretion of cholesteryl ester transfer protein from hamster adipose tissue: stimulation by beta-adrenergic agents

High levels of cholesteryl ester transfer protein (CETP) favours decreased plasma high density lipoprotein cholesterol and increased levels of cholesterol in apolipoprotein B containing lipoproteins. Adipose tissue is one of the major sources of circulating CETP. Previous studies by our group and others demonstrated that the production of CETP from hamster adipose tissue increases after fasting, a metabolic state known to affect the sympathoadrenal axis. The present study examines the influence of beta-adrenergic agonists on the secretion of CETP from hamster adipose tissue. Fifteen minutes after an intraperitoneal injection of isoproterenol (12 microg/kg), the release of CETP mass and activity from adipose tissue fragments incubated in vitro were significantly increased. This was associated with an elevation in CETP mass and activity in plasma. The effects of isoproterenol on CETP release from adipose tissue and plasma CETP levels were suppressed by propranolol, a beta-adrenoceptor inhibitor. Addition of 10(-6) M isoproterenol to adipose tissue in vitro increased the release of CETP mass and activity from adipose tissue and this was also blocked by propranolol. Isoproterenol-induced secretion of CETP activity from adipose tissue was partially inhibited by cytochalasin B, an inhibitor of actin cytoskeleton reorganization. Forskolin, a classical adenylate cyclase agonist and 8-bromo-cAMP, a functional analogue of cAMP, mimicked the effect of isoproterenol on CETP release from adipose tissue. Our results suggest that isoproterenol increases the secretion of CETP from hamster adipose tissue through a beta-adrenoceptor and a cAMP-dependent pathway. Actin cytoskeleton reorganization may be required for secretion of CETP. The findings imply that the secretion of CETP from adipose tissue is under neurosympathetic control.

Supraglottic carcinoma: does preoperative radiotherapy reduce the incidence of cervical metastasis?

OBJECTIVE

To compare surgery (S) alone with combined radiotherapy and surgery (R + S) in the management of patients with supraglottic laryngeal cancer.

METHODS

Between 1981 and 1994, patients were stratified according to stage and randomised to either surgery (S) or 4000cGy of radiotherapy and surgery. There were 102 patients in the S group and 99 in the R + S group who completed at least 3-year follow-up.

RESULTS

Using Kaplan-Meier survival method showed no significant difference between the two groups. When the patients were grouped according to tumour stage, a significant reduction in the regional recurrence was noted in the R + S group for stage I-III disease (Cox multivariate analysis, P < 0.02). They had an increased relative risk of 1.8 (95% confidence 1.1-2.9) for neck recurrence. There was no significant difference in neck recurrence rates in the two groups for stage IV disease. When Cox proportional hazard model was used, only TNM stage (P < 0.02) and histological nodal status (positive lymph nodes, P < 0.01) were found to be independent risk factors for regional control.

CONCLUSION

Preoperative radiotherapy can improve regional cervical control of stage I-III supraglottic cancer as compared with surgery alone.

Time-resolved optical backscattering model in highly scattering media

A time-resolved backscattering model, which combines a single large-angle scattering with multiple small-angle scatterings, is used to produce a scattered-light profile about a medium. Inhomogeneity of the medium is included in the model. Some multidimensional integrals can be evaluated analytically.

High-resolution restriction maps of bacterial artificial chromosomes constructed by optical mapping

Large insert clone libraries have been the primary resource used for the physical mapping of the human genome. Research directions in the genome community now are shifting direction from purely mapping to large-scale sequencing, which in turn, require new standards to be met by physical maps and large insert libraries. Bacterial artificial chromosome libraries offer enormous potential as the chosen substrate for both mapping and sequencing studies. Physical mapping, however, has come under some scrutiny as being "redundant" in the age of large-scale automated sequencing. We report the development and applications of nonelectrophoretic, optical approaches for high-resolution mapping of bacterial artificial chromosome that offer the potential to complement and thereby advance large-scale sequencing projects.

Structural motifs in rheumatoid T-cell receptors

The linkage of rheumatoid arthritis (RA) to HLA-DR haplotypes, high levels of HLA-DR expression, and T-cell infiltration in the joints, indicate a central role for the interaction of T-cell receptors (TCR) with antigen (Ag) + major histocompatibility complex (MHC) complexes in pathogenesis. Receptor analysis in RA has uncovered a restricted heterogeneity of TCR transcripts, suggesting an antigen-driven response. We analyzed the sequence and structural features of RA-associated TCRs in light of the recently published TCR crystal structures. The surface-exposed residues of the third complementarity-determining region (CDR3s) showed preferential use of certain amino acid residues when sequences derived from synovial fluid or tissue were compared with those derived from peripheral blood, particularly for alpha chains. Sequence alignment of oligoclonal synovial TCR CDR3s revealed groupings with similar CDR3 lengths and amino acid compositions, which suggests shared antigen recognition. Given the limitations of analyzing TCR sequences without knowing their structures, we developed several in vivo-activated synovial-tissue Vbeta17 + RA T-cell clones. Two Vbeta17/V alpha7 clones with different CDR3 sequences were analyzed by molecular modeling. Although distinct topologic features were seen, a central patch of residues with similar chemical and geometric characteristics was present in both. Electrostatic maps revealed similar binding surfaces of both alpha domains and central patches, with differences in the beta domains. This suggests that an alpha-domain-focused binding trajectory would allow shared antigen recognition by these TCRs. These studies support recognition of a limited diversity of Ag + MHC complexes by synovial RA TCRs.

[Effect of 5-HT and somatostatin on SP and chronic pain initiated electrical activity of neurons in spinal dorsal horn]

The effects of SP on the electric activities of neurons of spinal dorsal horn and the influence of 5-HT, somatostatin (SOM) on the effects of SP were observed in anesthetized rats with multimicropipete and iontophoresis techniques. It was found that: (1) The microiontophoretically administrating of SP could increase spinal dorsal horn unit discharge. (2) The noxious electrical activity of neurons induced by formalin could be inhibited by microiontophoretically applied SP. (3) The microiontophoretically administrating of 5-HT and SOM could inhibit the SP and formalin evoked unit discharge of neurons in spinal dorsal horn. It was suggested that SP took a double-effect part in modulation of pain transmission and analgesia in spinal cord, 5-HT and SOM inhibited the effect of SP and participated in pain modulation of SP.

Optical levitation measurements with intensity-modulated light beams

Illumination of an optically levitated particle with an intensity-modulated transverse beam induces a transverse vibration of a particle in an optical trap. Based on this, the trapping force of a trap can be measured. Using an intensity-modulated longitudinal levitating beam causes a particle to move vertically, allowing for the determination of some aerodynamic parameters of a particle in air. The principles and the experimental phenomena are described and the initial results are given.

[Purification, serology and detection of grapevine leaf roll virus]

Closterovirus-like particles associated with grapevine leaf roll disease were purified from stem phloem tissue by differential centrifugation and cesium sulphate-sucrose density gradient centrifugation. The particles were between 660-2000 nm long. Most of them were about 1400 nm long and also decorated by the antiserum against GLRV NY-1 isolate. The purified preparation was tested for their serological relatedness in indirect ELISA. The results indicated that these closterovirus-like particles reacted with serotype II, III and IV of GLRV. The antiserum to NY-1 (type III) reacted more strongly than type IV (to VA-4) and type II. (to 1800 nm). In sodium dodecyl sulfate immunodiffusion test, the extract of diseased petiole reacted with serotype III, IV and II. It is possible to be infected by 2 or 3 closterovirus-like particles in China. We have made antiserum to the purified closterovirus-like GLRV and set up a PAS-ELISA to detect GLRV-free grapevine plantelets. We have obtaimed 21 varieties of GLRV-free and GFLV-free grapevine. They shown high quality and quantity in field test.

Changes of ultrasonography and two serum biochemical indices for hepatic fibrosis in schistosomiasis japonica patients one year after praziquantel treatment

OBJECTIVE

To observe the changes of abdominal sonography and 2 biochemical indicators for hepatic fibrosis before and after treatment with praziquantel in schistosomiasis japonica patients.

METHODS

Fifty-five persons infected with Schistosoma japonicum and treated with praziquantel were examined with ultrasonography and serum hyaluronic acid (HA) and type III procollagen (PC III) before and 1 year after treatment, and their data were compared with those in 55 normal controls.

RESULTS

With comparison of the data before praziquantel treatment, the length of the left liver lobe and the spleen in 55 patients all decreased (P < 0.01) 1 year after treatment. No significant change was seen in interior diameter (d) of the portal vein, while a decrease in the ratio of the exterior diameter (D) and interior diameter of the second branch of the portal vein was very significant (P < 0.01). Compared with the data in normal control, significantly higher levels in the thickness of the left lobe, the maximum oblique diameter of the right lobe, the length of the spleen, spleen index, the interior diameter of the portal vein and D/d ratio were seen in the patients both before and after treatment. The abnormal rate of the 2 serum parameters for hepatic fibrosis decreased significantly after treatment.

CONCLUSIONS

Parameters of hepatic fibrosis either by ultrasonography or by the 2 biochemical tests showed a significant improvement in 55 patients 1 year after treatment, although some of the indices did not yet return to normal levels.

Differential structuring of human populations for homologous X and Y microsatellite loci

The global pattern of variation at the homologous microsatellite loci DYS413 (Yq11) and DXS8174 and DXS8175 (Xp22) was analyzed by examination of 30 world populations from four continents, accounting for more than 1,100 chromosomes per locus. The data showed discordant patterns of among- and within-population gene diversity for the Y-linked and the X-linked microsatellites. For the Y-linked polymorphism, all groups of populations displayed high FST values (the correlation between random haplotypes within subpopulations, relative to haplotypes of the total population) and showed a general trend for the haplotypes to cluster in a population-specific way. This was especially true for sub-Saharan African populations. The data also indicated that a large fraction of the variation among populations was due to the accumulation of new variants associated with the radiation process. Europeans exhibited the highest level of within-population haplotype diversity, whereas sub-Saharan Africans showed the lowest. In contrast, data for the two X-linked polymorphisms were concordant in showing lower FST values, as compared with those for DYS413, but higher within-population variances, for African versus non-African populations. Whereas the results for the X-linked loci agreed with a model of greater antiquity for the African populations, those for DYS413 showed a confounding pattern that is apparently at odds with such a model. Possible factors involved in this differential structuring for homologous X and Y microsatellite polymorphisms are discussed.

[Recombinant AAV-LMP-induced LMP specific cytotoxic response to autologous lymphoblastoid cell lines tranformed by Epstein-Barr virus]

Epstein-Barr virus is believed to be controlled in normal host by virus specific cytotoxic T lymphocytes (CTL). Although unable to eliminate EBV from the body, CTL seems to be essential in control of latently infected cells. Infusion of autologous EBV specific CTL, which can be produced in laboratory by separating lymphocytes from patients and stimulating them with EBV antigen, will provide an effective method of preventing and treating EBV-related diseases. We inserted the LMP gene of EB virus into an AAV vector pACP and packed it in Ad2 infected 293 cells by co-transfecting with plasmid Ad8, which produced the recombinant virus rAAV-LMP. The recombinant virus was used to infect stimulating cells and LMP antigen was expressed on the surface of these cells. Then the stimulating cells were irradiated and co-cultured with T lymphocytes. The EBV specific CTLs were obtained. The target cells were autologous LCLs from EBV-transformed B lymphocytes. The CTL activity was assayed by BLT activity method. The result indicated that all the four CTL strains could recognize and kill their target cells. This study has laid the technical basis for us to prevent and treat nasopharyngeal carcinoma in China with molecular biological methods.

Effect of hypoxia on blood glucose, hormones, and insulin receptor functions in newborn calves

At between 7 and 11 h after delivery, 14 fasted calves were randomly divided into two groups to examine the effects of neonatal hypoxia on blood glucose metabolism and its mechanisms. One group was subjected to breathe a gas mixture containing 4.8-5.9% oxygen in nitrogen from a hood for 2 h. The second control group breathed atmospheric gas. Several possible causes of changes in blood glucose were assessed, including insulin, glucagon, and hydrocortisone as prereceptor factors, insulin binding as a receptor factor, and insulin receptor tyrosine kinase (IR-TK) activity as a postbinding factor. The hypoxic animals exhibited increased concentrations of blood glucose (from 5.47 +/- 1.61 mmol/L to 7.97 +/- 1.30 mmol/L), plasma insulin, and hydrocortisone, but decreased concentrations of glucagon. The percentage of specific binding activity decreased in the hypoxic group compared with the control group (12.71 +/- 1.25% versus 15.14 +/- 1.27%, p < 0.01). Several parameters of insulin receptor binding, i.e. affinity constants, high and low binding capacities, and numbers of binding sites, showed a tendency to decrease after hypoxia. Only lower affinity binding sites decreased significantly. At the postreceptor level, IR-TK activity was decreased in the hypoxic group compared with controls. It is concluded that hypoxia induced insulin resistance in these newborn calves. The results suggest that the primary mechanism for insulin resistance in the hypoxic newborn was reduced insulin receptor responsiveness with attenuated activity of IR-TK at the postreceptor level.

The role of Fas/APO 1 and apoptosis in the development of human atherosclerotic lesions

The possibility that Fas/APO 1 is involved in the apoptosis of advanced human coronary atherosclerosis was examined in the present study. Coronary arteries with atherosclerosis were obtained from human hearts with chronic ischemic heart disease at cardiac transplantation. Normal vessels were used as controls. Fas/APO 1 was detected by immunohistochemistry with a monoclonal antibody. Apoptotic cells were stained in situ by terminal deoxynucleotidyl transferase mediated-dUTP nick end labeling (TUNEL) and DNA fragmentation into oligonucleosomes was checked by gel electrophoresis. Bcl-2, an antiapoptotic oncoprotein, was detected by immunohistochemistry and Western blot. Apoptotic cells were present in the neointima in all stages of atherosclerosis, and in intraplaque small vessels. In initial lesions, only a few cells were undergoing apoptosis. By contrast, in advanced lesions, many cells were found to undergo apoptosis. Apoptosis was further confirmed by genomic DNA analysis using gel electrophoresis. Apoptotic cells were either smooth muscle cells or macrophages, but also endothelial and blood borne cells. Fas/APO 1 was present in foam cells. Most of the Fas/APO 1 positive cells were stained for the macrophage marker CD68 and for alpha-smooth muscle actin in serial sections. Several anti-Fas/APO 1 positive foam cells were revealed to undergo apoptosis by double staining. Bcl-2 was detected in Fas/APO 1 expressing plaques. A number of CD3-positive T-lymphocytes were found around foam cells expressing Fas/APO 1. This data suggests that Fas/APO 1 regulated apoptosis is involved in the development of advanced human atherosclerotic lesions and that it probably determines the amount of tissue mass in the diseased vessels.

Expression of proliferating cell nuclear antigen in Wilms' tumor

OBJECTIVE

To investigate the expression of proliferating cell nuclear antigen (PCNA) and its clinical significance in Wilms' tumor.

METHODS

PCNA immunoreactivity on paraffin-embedded tissues was assessed retrospectively in 35 cases using labelled streptaridin biotin (LSAB) procedure, and its association with clinical and other biological features was studied.

RESULTS

Twelve tumors (34.29%) expressed PCNA. Expression rate increased with the advance of stage (P < 0.05). The S-phase fraction and proliferation index (PI) in children with PCNA positive expression were higher than those in children with negative PCNA expression (P < 0.05). The survival rate (16.67%) in patients with positive PCNA expression was significantly lower than that (73.91%) in no-expression ones (P < 0.01).

CONCLUSION

PCNA is a sensitive indicator for cell proliferation and is clinically useful in identifying a poor prognostic group of patients with Wilms' tumor.

Pravastatin increases survival and inhibits natural killer cell enhancement factor in liver transplanted rats

Pravastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, has been shown to decrease the number of acute rejection episodes in cardiac and renal transplant patients. This study evaluates the effects of pravastatin on survival of rats following liver transplant and attempts to elucidate the mechanisms of these effects. Both survival and natural killer cell enhancing factor (NKEF) studies utilized Dark Agouti rats for donor livers transplanted into Brown Norway rats as recipients. All rats received daily low-dose cyclosporine (CsA) 2 mg/kg/day by gavage. The treated groups also received gavage doses of pravastatin, 20 mg/kg/day. Survival data were analyzed by the method of Kaplan-Meier and log-rank chi 2 tests for statistical significance. For NKEF evaluation, rats were sacrificed at varying time points; total RNA was extracted from the liver and hybridized with 32P-radiolabeled NKEF DNA probes in the Northern blot technique. Radiographs were quantitated using densitometry. Data were analyzed by two-way ANOVA. Actuarial survival was improved (P < < 0.05) in rats treated with pravastatin in addition to low-dose CsA (n = 41, CsA alone n = 74). Less fibrosis and chronic rejection was seen on histological section in the treated animal livers, P < 0.05, NKEF was seen maximally at Days 5-15 tapering off at Day 21. NKEF-a and NKEF-b levels were significantly decreased in the animals treated with CsA and pravastatin compared to CsA alone in the group of animals < 16 days postop (P < < 0.05). Pravastatin improves survival in rats following OLT and while the mechanism is still unknown, inhibition of natural killer cell enhancement factor may represent an alteration in the overall immune response.

[Intraparenchymal and intraventricular transplantation of fetal substantia nigra cell suspension in rat model of Parkinson's disease]

The grafts of fetal substantia cell suspension grafts could bring into a behavioral effect and characteristics of histology and immunocytochemistry in rat models of PD after the grafts were transplanted either into the lateral ventricles or directly into the striatum. It was found that the intraparenchymal tromsplantation of fetal nigral cell suspensions not only was beneficial to reinnervation between host and grafts, but also produced more complete and steady effects than the intraventricular transplantation. We concluded that the restoration of nervous functional deficits of PD rats is likely to depend on both extensive dopaminergic reinnervation throughout the grafted sites and on closer integration of the grafts with the host striatal circuitry.

Adrenal proteins bound by a reactive intermediate of mitotane

PURPOSE

Mitotane (o,p'-DDD), is the only adrenolytic agent available for the treatment of adrenocortical carcinoma. Previous studies have shown that mitotane covalently binds to adrenal proteins following its metabolism in adrenocortical tissue to a reactive acyl chloride intermediate. It was the objective of this study to compare the electrophoresis separation patterns of such adducts following activation of mitotane by various adrenocortical sources.

METHODS

With the use of a 125I-labeled analog of mitotane, 1-(2-chlorophenyl)-1-(4-iodophenyl)-2,2-dichloroethane, gel electrophoresis patterns were obtained for homogenates from bovine, canine and human adrenocortical preparations as well as from a human adrenal preparation. Western immunoblotting analysis was used to test the resulting patterns for adducts of cytochrome P-450scc and adrenodoxin.

RESULTS

The electrophoresis separations were similar for all preparations, with bands at apparent molecular weights of 49.5 and 11.5 kDa being the most pronounced. Radiolabeling of the proteins of a human adrenal cancer cell line NCI H-295 was weak, but a band at 11.5 kDa was detected. Western immunoblotting analyses indicated that the band at 49.5 kDa corresponded in molecular weight to that of adrenal cytochrome P-450scc, but the band at 11.5 kDa did not correspond to adrenodoxin.

CONCLUSIONS

The similarity of the results with canine and bovine adrenal preparations to that of human material offers useful systems for studying mitotane and its analogs. This should aid in understanding the mechanism of action of mitotane and in the design of compounds for the treatment of adrenocortical carcinoma.

[Long-term survival of fetal substantia nigra grafts in striatum of PD rats: an observation of tyrosine hydroxylase immunohistochemistry and western blot]

By using immunohistochemistry and Western blot, we observed the varied patterns of survival, development and growth of dopaminergic neurons after intrastriatal transplantation of fetal substantia nigra. There was a phenomenon of "developmental delay" of grafts in the host. As the time of transplantation went on, the grafted dopaminergic neurons could reinnervate the host neurons. The observation reveals that the reinnervation between graft and host is more beneficial to the functioning of the grafts.

Direct bladder stimulation with suture electrodes promotes voiding in a spinal animal model: a technical report

To determine the efficacy of a new electrode for direct bladder stimulation, five male cats were instrumented during anesthesia. Multistranded, 316LVM, stainless-steel, wire electrodes were implanted on the bladder wall serosa above the trigone area. The electrodes were made with a needle attached to the end that was cut off after suturing the electrode in place. Additional instrumentation included tubes for pressure recording and filling, and hook electrodes for leg and pelvic floor EMG recording. Bladder filling and stimulation studies were conducted in tethered animals 1 to 2 weeks following recovery. Chronic studies were conducted following recovery in tethered animals. To test these electrodes in a spinal cord injury (SCI) model, a T-1 level complete lesion was performed on the above instrumented animals. Spinal animals had successful direct bladder stimulation that induced active contractions and voiding both before and after SCI, but voiding rates were higher more than 2 weeks after SCI and at larger initial bladder volumes. Optimum stimulation parameters consisted of 40 pulses per second, 300 microseconds to 1 ms pulse duration, a stimulation period of 3 to 4 s, and 10 to 40 mA. Urethral resistance, indicated by a urethral function measure, showed that stimulation had no adverse effect on urethral function, and fluoroscopy showed an open membranous urethra during stimulation and voiding. The cat has a small penile urethra that is the flow rate controlling zone. The suture electrode did not corrode, erode into the bladder, or become dislodged, and appears suitable for chronic implantation.

Sequence and transcription of Qa-2-encoding genes in mouse lymphocytes and blastocysts

The protein product of the mouse preimplantation embryo development (Ped) gene, which controls the rate of preimplantation embryonic cleavage division and subsequent embryo survival, is the Qa-2 antigen. This major histocompatibility complex (MHC) class I b protein is encoded by four genes, Q6, Q7, Q8, and Q9. The present study was undertaken to begin to elucidate which of the four Qa-2-encoding genes are responsible for the Ped gene phenotype in the C57BL/6 mouse (H2(b)). First, restriction maps of the four genes, using 25 restriction enzymes, were created. The RE maps confirmed that Q6 is similar to Q8 and Q7 is similar to Q9, but that the Q6/Q8 gene pair differs from the Q7/Q9 gene pair. The genomic DNA sequences of Q6 and Q8 were determined, as well as the DNA sequences of exons 4 - 8 of Q9, and the 5' regulatory regions of Q6, Q8, and Q9. This DNA sequence information, combined with the published DNA sequence information for the entire Q7 gene and exons 1 - 3 of Q9, allowed us to design primers for reverse transcription-polymerase chain reaction that could distinguish which of the four genes were transcribed in mouse lymphocytes and embryos. It was found that all four genes are transcribed in lymphocytes, but only Q7 and Q9 are transcribed in mouse embryos. Thus, both Q7 and Q9 are candidates for the genes responsible for the Ped gene phenotype.

Transcription-modulating drugs: mechanism and selectivity

Transcription-modulating drugs achieve their therapeutic effects through the modulation of gene transcription. To understand how selectivity is achieved, four groups of such drugs - including immunosuppressants, estrogen analogs, the antidiabetic thiazolidinediones, and the anti-inflammatory salicylates - will be discussed. The immunosuppressants cyclosporin A and FK506, when complexed with immunophilins, inactivate the protein phosphatase calcineurin, resulting in the inhibition of interleukin-2 gene activation. Another immunosuppressant, rapamycin, binds to the same immunophilin as FK506 but inactivates a protein kinase p70(s6k). Estrogen analogs tamoxifen and rolaxifene antagonize one estrogen receptor transactivation function (AF-2) and agonize another (AF-1). They modulate expression of a wide variety of genes, including transforming growth factor-alpha, insulin-like growth factor-1, and transforming growth factor-beta3, which are important for breast and endometrial cancer proliferation and bone maintenance respectively. The antidiabetic drugs thiazolidinediones bind and activate peroxisome proliferator-activated receptor gamma and suppress insulin resistance mediated by tumor necrosis factor-alpha. Salicylates inhibit transcription factor NFkappaB, which is important for immune and inflammatory responses. Continuing understanding of molecular mechanisms of such drugs not only helps to identify better drugs for these targets but should also provide an insight into developing future transcription-modulating drugs with better selectivity and reduced toxicity.

Time-resolved optical diffusion tomographic image reconstruction in highly scattering turbid media

The image of an object hidden in highly scattering media was reconstructed using a fast, noise-resistant algorithm newly applied to diffusion tomography. A pulsed light source producing scattered and transmitted light is examined at multiple times. Multiple source detector pairs around the medium are used to obtain data in many different directions. An inverse scattering algorithm with nonuniform regularization achieves rapid inversion convergence.

The cost of coverage: rural health insurance in China

China has undergone great economic and social change since 1978 with far reaching implications for the health care system and ultimately for the health status of the population. The Chinese Medical Reform of the 1980s made cost recovery a primary objective. The urban population is mostly protected by generous government health insurance. A high share government budget is allocated to urban health care. Rural cooperative health insurance reached a peak in the mid-1970s when 90% of the rural population were covered. In the 1980s rural cooperative health insurance collapsed and present coverage is less than 8%. The decline has been accompanied by reports of growing equity problems in the financing of and access to health care. This article is the first in a four-year study of the impact on equity of the changes in Chinese health care financing. The article examines the relationship between rural cooperative health insurance as the explanatory variable and health care expenditure, curative vs. preventive expenditure and tertiary curative care expenditure as dependent variables using a natural experimental design with a 'twin' county as a control. The findings support the hypothesis that cooperative health insurance will induce higher growth of health care expenditure. The findings also support the hypothesis that cooperative health insurance will lead to a shift from preventive medicine to curative medicine and to a higher level of tertiary curative care expenditure. The empirical evidence from the Chinese counties is contradicting World Bank health financing policies.

Inhibition of restriction endonuclease activity by DNA binding fluorochromes

Activity of type II restriction endonuclease is affected by many common factors including buffer composition and sequences flanking the recognition site (Brabec et al., Eur.J. Biochem. 216, 183, 1993). The successful development of Optical Mapping (Schwartz et al., Science, 262, 110, 1993; Meng et al., Nature Genet. 9, 432, 1995; Wang and Schwartz, PNAS, 1995 Cai et al., PNAS, 92, 5164, 1995) relied on optimization of light microscope-based imaging of fluorescently labeled DNA molecules during restriction endonuclease digestion. Little was known about the effects of commonly used DNA-fluorochromes on restriction endonuclease activity. Thus, we developed an enzyme activity assay using lambda bacteriophage DNA or adenovirus-2 DNA to evaluate the effects of five DNA binding fluorochromes (4'-6-daimidine-2-phenylindole (DAPI), ethidium bromide (EtdBr), ethidium bromide homodimer (EthD-1), bis-benzimide (H33258) and benzothiazolium-4-quinolinium dimer (TOTO-1)) on the enzymatic activities of eleven type II restriction endonucleases (Asc I, Csp I, Dra I, EcoR I, Hha I, Hind III, Not I, Rsr II, Sfi I, SgrA I and Sma I). We found that the minor groove binding fluorochrome, DAPI, did not measurably inhibit activity of this group, with the exception of Dra I. Similarly, another minor groove binding fluorochrome H33258 inhibited Dra I and Not I (slightly). The three intercalating fluorochromes EtdBr, EthD-1 and TOTO-1, however, variably inhibited the other enzymes. Since Beta-mercaptoethanol (Beta-ME) is used to discourage photodamage of stained DNA molecules, we also assessed its effect on restriction endonuclease activity. Interestingly, Dra I, Hind III, Sfi I and Sma I retained full activities at high concentration of Beta-ME (5%), but Asc I, Csp I, Not I, Rsr II and SgrA I showed varying sensitivities to the Beta-ME. Isoschizomers Csp I and Rsr II behaved differently to both fluorochromes and Beta-ME. The results presented here should provide a basis for further development of new Optical Mapping-based techniques requiring fluorescence labeling of other actively imaged enzymatic reactions.

Novel tetranucleotide repeat polymorphism in the human adenosine deaminase gene: interethnic comparison of three major human groups

A new tetranucleotide repeat polymorphism was revealed at the human adenosine deaminase (ADA) locus by using the polymerase chain reaction and denaturing polyacrylamide gel electrophoresis. Allele frequencies were estimated in seven populations from three major ethnic groups. Heterozygosity values were calculated and found to differ significantly between Africans and non-Africans.

Identification of seven new human MHC class I region genes around the HLA-F locus

Using cDNA hybridization selection techniques, we identified seven new genes in a 280 kilobase YAC covering the HLA-F locus. The new genes were mapped back to the YAC by a combination of optical restriction mapping and pulse field gel electrophoresis. Northern analysis of individual clones demonstrated the presence of either different mRNA sizes or different expression patterns. Two of the cDNA clones were expressed only in lymphoid cell lines: one in Jurkat cells (T cell) and another in JY cells (B cell). All the genes lacked sequence similarity to any known classical and non-classical major histocompatibility complex (MHC) class I genes, indicating that the MHC class I region has more functions than anticipated. Of the seven new genes, one is highly similar (97%) to mouse 60S ribosomal protein, and another is homologous to diubiquitin proteins. Of the two G-coupled receptor-like cDNAs, one was fully sequenced and found to be an olfactory receptor-like gene. The study strengthens evidence that the MHC complex not only plays a key role in the immune system, but also contributes to non-immunological functions.

The cloning, sequence analysis, and expression in E. coli of coat protein gene of grapevine fanleaf virus Gh

Fragments of 5' end and 3' end of the coat protein gene of a Chinese strain grapevine fanleaf virus (GFLV-Gh) were separately amplified through RT-PCR. The two products were cloned and ligated into a complete full-length coat protein gene via an inherent BgIII restriction site. The entire gene contains 1512 nucleotides which encode a 504 amino acids coat protein, molecular weight approximately 56 kDa. Comparison with GFLV F-13 shows 88.4% homology in nucleotides and 95.8% similarity in deduced amino acid residues. Also this coat protein gene was expressed in E. coli DH 5 alpha.

Optical mapping: a novel, single-molecule approach to genomic analysis

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Ordered restriction endonuclease maps of yeast artificial chromosomes created by optical mapping on surfaces

We have developed a surface mounting technology for the rapid construction of ordered restriction maps from individual DNA molecules. Optical restriction maps constructed from yeast artificial chromosome DNA molecules mounted on specially derivatized glass surfaces are accurate and reproducible, and the technology is amenable to automation. The mounting procedures described here should also be useful for fluorescence in situ hybridization studies. We believe these improvements to optical mapping will further stimulate the development of nonelectrophoretic approaches to genome analysis.