Prevalence of CMV in arterial walls and leukocytes in patients with atherosclerosis

OBJECTIVE

To investigate the association of cylomegalovirus with atherosclerosis.

METHODS

The presence of cylomegalovirus (CMV) nucleic acids was demonstrated in carotid and coronary arteries of patients with and without atherosclerosis by polymerase chain reaction (PCR). CMV was detected by PCR in the blood of patients with and without atherosclerosis.

RESULTS

83.3%-86.7% of the samples obtained from atherosclerotic patient arterial walls were shown to contain viral nucleic acids (CMV), CMV could be found among 6.7% of patients' arterial wall without atherosclerosis, significant difference can be found between them (P < 0.01). In blood CMV could be found in 42.4% of patients with atherosclerosis, in the control group, only 3% of samples had CMV, P < 0.01.

CONCLUSION

CMV plays an important role in the pathologic process of the atherosclerosis and the atherosclerotic cerebral infarction.

Effect of long-term exposure to fluoride in drinking water on risks of bone fractures

Findings on the risk of bone fractures associated with long-term fluoride exposure from drinking water have been contradictory. The purpose of this study was to determine the prevalence of bone fracture, including hip fracture, in six Chinese populations with water fluoride concentrations ranging from 0.25 to 7.97 parts per million (ppm). A total of 8266 male and female subjects > or =50 years of age were enrolled. Parameters evaluated included fluoride exposure, prevalence of bone fractures, demographics, medical history, physical activity, cigarette smoking, and alcohol consumption. The results confirmed that drinking water was the only major source of fluoride exposure in the study populations. A U-shaped pattern was detected for the relationship between the prevalence of bone fracture and water fluoride level. The prevalence of overall bone fracture was lowest in the population of 1.00-1.06 ppm fluoride in drinking water, which was significantly lower (p < 0.05) than that of the groups exposed to water fluoride levels > or =4.32 and < or =0.34 ppm. The prevalence of hip fractures was highest in the group with the highest water fluoride (4.32-7.97 ppm). The value is significantly higher than the population with 1.00-1.06 ppm water fluoride, which had the lowest prevalence rate. It is concluded that long-term fluoride exposure from drinking water containing > or =4.32 ppm increases the risk of overall fractures as well as hip fractures. Water fluoride levels at 1.00-1.06 ppm decrease the risk of overall fractures relative to negligible fluoride in water; however, there does not appear to be similar protective benefits for the risk of hip fractures.

[A comparison of the effects of PAV, PSV and IPPV on cardiopulmonary function in patients with acute respiratory failure]

OBJECTIVE

Comparing the effects of proportional assist ventilation (PAV), pressure support ventilation (PSV), and intermittent positive pressure ventilation (IPPV) on cardiopulmonary function in patients with acute respiratory failure, in particular, evaluating the clinical significance of PAV.

METHODS

Ten patients with acute respiratory failure were firstly ventilated with IPPV. Elaslance (Ers) and Resistance (Rrs) were measured and calculated. Then PSV mode was adapted. Based on the parameters of IPPV, inspiratory positive airway pressure was adjusted to maintain the same tidal volume (V(T)) as that in IPPV. Finally PAV mode was used. According to the parameters of PSV, the assist ratio was adjusted to maintain the same V(T) and peak pressure peak, as those in PSV. Respiratory mechanics, arterial blood gas and hemodynamics were recorded during above three modes of ventilation.

RESULT

Comparing with PSV and IPPV mode, PAV created a significantly lower peak, less work of breathing of patients (WoBp) and work of breathing of ventilation (WoBv) under the similar V(T); Central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) were significantly lower in PAV mode as compared with those in IPPV; While comparing with PSV, V(T), mean blood pressure (mBP) and cardiac output (CO) were higher and mean pulmonary arterial pressure (mPAP), WoBp were lower in patients with PAV under similar peak. Among them the fall of WoBp was statistically significant.

CONCLUSION

In patients receiving three modes of ventilation, PAV presents with lower airway pressure, less WoBp and less effect on hemodynamics as compared with those with PSV or IPPV.

Cloning and characterization of P110, a novel small nucleolar U3 ribonucleoprotein, expressed in early development

We report the cloning of a BrdU-sensitive transcript of 4.1 kb from an immortalized quail heart cell line containing an open reading frame of 940 amino acids (110 kDa, pI approximately 5.18). The mRNA encoding P110 appears in the heart and neural tube by 36 h of avian development, at a time when these organs are rapidly developing. Analysis of the DNA-deduced protein sequence revealed a bipartite nuclear localization signal, and a highly charged domain rich in both acidic and basic residues. Immunofluorescent staining with polyclonal antibodies raised against a P110 peptide localized the protein to the nucleolus of avian and mammalian cells. Although database search showed significant homology with an uncharacterized cDNA from human brain and several human and mouse Expressed Sequence Tags, there was no close homology to known nucleolar proteins. Immunoprecipitation of P110 from cell sonicates revealed it contained U3 small nucleolar RNA, but no significant amounts of other box C/D small nucleolar RNAs. These data suggest that P110 is one of the U3 small nucleolar ribonucleoproteins that are involved in rRNA processing.

Increase of calmodulin III gene expression by mu-opioid receptor stimulation in PC12 cells

Calmodulin (CaM) is a principal multifunctional mediator of Ca2+ signaling in cells. It is reported that morphine increases CaM contents in mouse brain. However, the precise mechanism of CaM induction by morphine is unknown. We investigated the changes of CaM by opioid receptor stimulation in mRNA and protein levels. Expression of CaM was increased in dose- and time-dependent manners by morphine with RT-PCR assay in PC12 cells, and naloxone inhibited the effect of morphine. The expression was also increased with DAMGO (mu-opioid agonist), but not by DPDPE (delta) and U50488 (kappa). Northern blot analysis revealed that the CaMIII gene was responsive to morphine or DAMGO. CaM protein increased by DAMGO were distributed in both soluble and membranous fractions in the cells. Taken together, the data suggest that morphine induces the expression of CaMIII gene through mu-opioid receptor stimulation.

On the behavior of alpha,beta-unsaturated thioaldehydes and thioketones in the Diels-Alder reaction

Alpha,beta-unsaturated thioaldehydes and thioketones, R1CH=CH-C(=S)R2, are prepared in situ by the reaction between the corresponding carbonyl compounds and bis(dimethylaluminum) sulfide. These compounds undergo [4 + 2] self-dimerization reactions in which one molecule serves as the heterodiene component and the other as the dienophile to afford different types of dimeric products depending on the R1 and R2: 1,2-dithiin and 1,3-dithiin (R1 = R2 = H), 1,2-dithiin (R1 = Ph, R2 = H, CH3), or dihydrothiopyran (R1 = R2 = Ph). These differences in selectivity are explained on the basis of the relative energies evaluated by molecular orbital (MO) calculations at the DFT (density functional theory) level. The calculations show that in the dimerization reaction of thioacrolein (I), the head-to-tail (S-C-S bonded) dimers are kinetically more stable by about 5 kcal/mol but slightly thermodynamically unstable by about 2 kcal/mol than the head-to-head (S-S bonded) dimers. The calculations on thiocinnamaldehyde (IV) indicate that the dimerization reactions of phenyl-substituted alpha,beta-unsaturated thioaldehydes and thioketones are almost equally controlled by thermodynamic and kinetic factors. These unsaturated thiocarbonyl compounds also function as heterodienes (C=C-C=S) in the cycloaddition reaction with norbornadiene and as dienophiles (C=S) in the reaction with cyclopentadiene.

Adult aortic arch atresia

Atresia in the aortic arch is a rare and severe congenital cardiovascular anomaly. Without surgical therapy, only a few patients can survive to adulthood. A 29-year-old woman with atresia of the aortic arch (Celoria-Patton Type A) without any intracardiac shunt underwent primary surgical correction involving reconstruction of the aortic arch with prosthetic interposition between the transverse aortic arch and the descending aorta and division of the persistent ductus arteriosus. Her postoperative course was uneventful, and she is now doing well at three years to date after surgical treatment.

[Nasal or oranasal face mask mechanical ventilation in the treatment of acute respiratory distress syndrome]

OBJECTIVE

To Evaluate the effect of nasal or oranasal face mask mechanical ventilation (FMMV) in the treatment of patients with acute respiratory distress syndrome(ARDS).

METHODS

16 ARDS patients were separated into two groups: infection group and non-infection group. The former had 6 cases with pneumonia and 1 case with sepsis; the later had 5 cases with multiple fracture, 2 with operation of intestines obstruction, 1 with operation of spleen rupture, 1 with hepatectomy. In Infection group, the respiratory rate(RR) was (46 +/- 5) times/min, the arterial blood pH 7.49 +/- 0.05, CO2 partial pressure(PaCO2) was (32 +/- 4) mm Hg, and oxygenation index (OI) (144 +/- 23) mm Hg. In non-infection group, the RR, pH, PaCO2, OI was (41 +/- 6) times/min, 7.49 +/- 0.13, (32 +/- 5) mm Hg, (156 +/- 51) mm Hg. All patients were linked with ventilator via nasal or ornasal mask. Pressure support ventilation (PSV) and positive end-expiratory pressure (PEEP) were selected.

RESULTS

All patients successfully received FMMV. In infection group, RR and OI returned to (45 +/- 7) times/min (P > 0.05) and (195 +/- 30) mm Hg(P < 0.05) respectively after 2-8 hours via FMMV. But in non-infection group, the RR and OI were (35 +/- 4) times/min (P < 0.05) and (228 +/- 90) mm Hg(P < 0.05). 2 cases(29%) in infection group and 8 cases(89%) in non-infection were successfully weaned from FMMV.

CONCLUSION

FMMV could be as the first choice in ARDS patients without infection, and airway intubation should be given in infectious patients as early as possible.

[Lung injury caused by passive smoking and its effects on cytokines in rats]

OBJECTIVE

A rat model with chronic bronchitis was replicated by passive inhalation of cigarette smoking fume to study its long-term effects on lung injury and nitric oxide (NO), interluekin-6 (IL-6), interleukin-8 (IL-8).

METHODS

Levels of nitrogen dioxide (NO(2)) and nitrogen trioxide (NO(3)) were measured with spectrophotometry in rats indicating their level of nitric oxide (NO). Levels of IL-6 and IL-8 were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Levels of NO in serum, bronchial alveolar lavage fluid (BALF) and lung tissue in the smoking group were significantly lower than those in the normal controls (P < 0.01). But, levels of IL-6 and IL-8 were higher in the smoking group than those in the controls.

CONCLUSION

Long-term passive smoking could cause injury of lung tissue to certain extent, reduction in secretion of NO in endothelial cells and damage to pulmonary vessels.

The diagnostic value of total respiratory impedance by impulse oscillometry in chronic obstructive lung disease

OBJECTIVE

To investigate the diagnostic significance of total respiratory impedance for chronic obstructive lung disease.

METHODS

The impedance of respiratory system was measured by impulse oscillometry method and compared with parameter values of routine pulmonary function in 57 patients with chronic obstructive pulmonary disease (COPD).

RESULTS

It significantly increased in viscous resistance ranging from 5 Hz and 35 Hz and resonant frequency in COPD group than that in healthy group. Reactance from 5 Hz and 35 Hz in COPD group was marked lower than that in healthy group. There were marked frequency dependence of viscous resistance and reactance in COPD patients. Resonant frequency was markedly and negatively correlated with parameters of pulmonary ventilation indices; X5 was positively correlated with parameters of pulmonary ventilation indices. But no statistical correlation was showed between R20 and parameters of pulmonary ventilation indices. Correlation was found between resonance frequency and FEV1, resonance frequency and Vmax. The correlation coefficient values were -0.671 and -0.666 respectively. The sensitivity of resonant frequency, R5 and X5 for diagnosing COPD were 94.74%, 59.65% and 54.38%, respectively. The specificity of them were 86.66%, 96.66% and 90%, respectively.

CONCLUSIONS

Resonant frequency was the most sensitive index in the parameters measured by IOS for diagnosing COPD. Since impedance measurement was a non-invasive method and only passive co-operation of the patient was needed. This technique could therefore be applied in COPD patients with acute attack for dynamic examination.

[A case report of surgical repair of ruptured aneurysm of sinus valsalva in aged (84 years old)]

An 84-year-old man with ruptured aneurysm of Valsalva sinus was operated. Diagnosis was made by two dimensional echocardiography, cardiac catheterization, and cardiac angiography. A aneurysm was found at the right-coronary sinus region, and ruptured into the right ventricle. The ruptured aneurysm of sinus Valsalva was repaired with direct closure and Woven patch from inside the right ventricle through the pulmonary valve. This case was defined as congenital because there was no sign of inflammatory or atherosclerotic changes in the aorta, aortic valve and aneurysm. The ruptured aneurysm of sinus Valsalva is very rare in aged patients. As far as we know, this patient is one of the oldest cases who underwent successful surgical repair in this country.

[The experimental study on improved cuirass-respirator]

OBJECTIVE

To study the factors that possibly affect the ventilatory efficiency of cuirass-respirator.

METHODS

Cuirass shells were constructed with plaster casts according to the shape of dog's chest wall. Above the cuirass shell, two straps were added in order to hold the cuirass shell when the pump generated pressure. Tidal volume and Pab and Pes were measured during different negative pressure. In addition, tidal volume was recorded before and after the cuirass was held.

RESULTS

Ventilatory efficiency was markedly raised after the cuirass was held. As negative pressure rose, ventilation increased and Pdi decreased.

CONCLUSIONS

The improved cuirass respirator can markedly improve ventilatory efficiency.

[A simple method for the determination of tungsten ores by XRF spectrometer]

A method for the determination of the major elements in tungsten ore using X-ray fluorescence spectrometer (PW 1404) was proposed. Tungsten ore and pure WO3 were fused, of which glass disc was made with the mixing flux of both Li2B2O7 and Na2B2O7. WO3 (%) was calculated by the relative intensity of the analytical line. Satisfactory analytical results were obtained.

Three polymorphisms associated with low hepatic lipase activity are common in African Americans

We have shown previously that a hepatic lipase allele (designated -514T) is common among African Americans and contributes to low hepatic lipase activity in this population. To identify other hepatic lipase alleles associated with low hepatic lipase activity in this population, the coding region and intron-exon boundaries of the hepatic lipase gene were sequenced in 20 African American men with low hepatic lipase activity. Two polymorphisms (N193S and L334F) were associated with low post-heparin plasma hepatic lipase activity and were much more common in African Americans than in whites. This finding, together with our previous data on the -514T allele, indicates that at least three different hepatic lipase polymorphisms associated with low hepatic lipase activity are common among African Americans. Analysis of hepatic lipase haplotypes revealed that 97% of African Americans have at least one hepatic lipase allele that is associated with low hepatic lipase activity.

Exploring infrared wavelength matrix-assisted laser desorption/ionization of proteins with delayed-extraction time-of-flight mass spectrometry

We report a study of the application of delayed extraction (DE) to infrared-wavelength matrix-assisted time-of-flight mass spectrometry (IR-MALDI-TOF-MS) of proteins. The shapes of the spectral peaks obtained with DE-IR-MALDI-MS are compared with those obtained from the same samples and matrix using continuous extraction (CE) IR-MALDI-MS. Application of DE results in significant improvements in the peak resolution, revealing spectral features (in proteins with molecular masses < 12 kDa) that were not resolved in the corresponding CE-IR-Maldi mass spectra. Particularly significant is a series of peaks on the high mass side of the protonated protein peaks that arise through replacement of protons by adventitious sodium ions in the sample. We deduced that these sodium replacement species are a significant contributor to the broad tails (and resulting peak asymmetries) that are a feature of the DE-IR-MALDI mass spectra of proteins with molecular masses > or = 17 kDa. The peak width reduction observed in IR-MALDI by DE suggests that, as in UV-MALDI, the initial velocity distribution for ions produced in the MALDI process contributes to the peak broadness in the CE mass spectra. In a systematic comparison between DE UV-MALDI and DE IR-MALDI, we determined that photochemical matrix adduction is present in UV-MALDI but absent in IR-MALDI. In addition, we find that protein ions produced by IR irradiation are less internally excited (i.e., cooler), exhibiting less fragmentation, more Na+ replacement and/or unspecified noncovalent adduction, and more heme adduction with apomyoglobin. Thus, IR-MALDI appears to be a softer means for producing gas-phase protein ions than is UV-MALDI. It will be of considerable practical interest to determine whether large protein ions produced by IR-MALDI are sufficiently cool to survive transport through reflecting TOF mass spectrometers (without loss of small neutral species such as H2O, NH3, and CO2) and the extended time periods required for detection by quadrupole ion trap and Fourier transform ion cyclotron resonance mass analyzers.

Buccal absorption of etomidate from a solid formulation in dogs

Etomidate is typically administered i.v. for the induction of general anesthesia. We believe that oral transmucosal absorption may extend etomidate's use to premedication and conscious sedation. Our objective was to study the oral mucosal absorption kinetics and bioavailability of etomidate in a solid dose form in dogs. A solid dose form containing 50 mg of etomidate in sorbitol for buccal administration was prepared. Each dog was administered both i.v. etomidate and buccal etomidate on separate days. Serum etomidate concentrations after i.v. administration were fit to a two-compartment pharmacokinetic model. The rates at which etomidate enters the systemic circulation via buccal mucosal absorption were calculated from serum concentrations from mucosal and i.v. administrations using model-dependent constrained numerical deconvolution. The apparent permeability coefficient and bioavailability were also determined. The mean (+/- SD) maximal serum etomidate concentration after buccal mucosal absorption from the 50-mg dose unit was 239 +/- 79 ng/mL. The time to reach maximal serum concentration was 12.5 +/- 1.8 min. Peak absorption rate of etomidate into the systemic circulation was 832 +/- 417 microg/min. For all dogs, 90% or more of the absorption via buccal mucosa took place during the period in which the drug was in contact with the mucosa (15 min). The apparent transbuccal mucosal permeability coefficient was 9.1 +/- 4.2 x 10(-4) cm/s, higher than values of any other compounds examined. Bioavailability calculated using the area under the serum etomidate concentration versus time curve method and the deconvolution method was 13.6% +/- 10.7% and 16.6% +/- 7.6%, respectively. In conclusion, etomidate is highly permeable through the canine buccal mucosa.

IMPLICATIONS

Etomidate is highly permeable through the canine buccal mucosa. Both the onset and the termination of buccal mucosal absorption of etomidate are rapid, which suggests that titratable delivery of etomidate may be possible by buccal administration.

Isoform-specific redistribution of calcineurin A alpha and A beta in the hippocampal CA1 region of gerbils after transient ischemia

To investigate isoform-specific roles of Ca2+/calmodulin-dependent phosphatase [calcineurin (CaN)] in ischemia-induced cell death, we raised antibodies specific to CaN A alpha and CaN A beta and localized the CaN isoforms in the hippocampal CA1 region of Mongolian gerbils subjected to a 5-min occlusion of carotid arteries. In the nonischemic gerbil, immunoreactions of both isoforms were highly enriched in CA1 regions, especially in the cytoplasm and apical dendrites of CA1 pyramidal neurons. At 4-7 days after the induced ischemia, immunoreactivities of the CaN A alpha isoform in CA1 pyramidal cells were markedly reduced, whereas they were enhanced in the CA1 radiatum and oriens layers. In contrast, CaN A beta immunoreactivities were reduced in all layers of the ischemic CA1 region, whereas they were enhanced in activated astrocytes, colocalizing with glial fibrillary acidic protein. These findings suggest that up-regulation of CaN A alpha in afferent fibers in CA1 and up-regulation of CaN A beta in reactive astrocytes may be involved in neuronal reorganization after ischemic injury.

Structure, regulation and function of avian glypican

Glypicans are a group of membrane-bound heparan sulfate proteoglycans (HSPG) that are tissue specific and developmentally regulated. Transcripts for avian glypican are found in endocardial cushions, limb buds, somites and forebrain of early chick embryos. Since avian glypican is not well characterized, the cellular localization, regulation of expression, and possible function during cardiac development have been studied. A polyclonal antibody was raised against a 20-amino acid peptide corresponding to an antigenic sequence within avian glypican core protein. The antibody recognized the expressed core protein in bacterial lysates and the endogenous HSPG in the proteoglycan fraction from chick forebrain. Immunolocalization studies indicated that the core protein is associated with cell membranes. The level of mRNA for avian glypican in MEQC (myc embryonic quail cardiomyocytes) grown in medium containing 10% fetal calf serum was compared to the message levels in cells grown without serum for 3 days. By Northern analysis, glypican transcripts were increased markedly after serum starvation. Up-regulation of glypican transcripts by serum withdrawal was partially prevented by addition of TGFbeta-1 and bFGF, suggesting that these growth factors may regulate its expression. MEQC cells deprived of serum migrated into clumps that could be blocked by an antisense OND (oligodeoxynucleotide) to the mRNA encoding the avian glypican. The same antisense OND inhibited the migration of endothelial cells from chick tubular heart explants over the surface of collagen gels. These results indicate that avian glypican may play a role in cell migration during development of endocardial cushions.

Direct comparison of infrared and ultraviolet wavelength matrix-assisted laser desorption/ionization mass spectrometry of proteins

In an effort to gain an understanding of the processes governing matrix-assisted laser desorption/ionization (MALDI), we made a direct comparison of ultraviolet (UV)- and infrared (IR)-MALDI linear time-of-flight mass spectra of proteins obtained from the same samples and matrices (on the same sample surface), using two different lasers, each having short duration (< 10-ns) pulses, i.e., a tunable wavelength Nd:yttrium aluminum garnet (YAG) pumped optical parametric oscillator laser operating at 2.94 microns and a Nd:YAG laser operating at 355 nm. We observed that (1) the IR-MALDI and UV-MALDI spectra of a given protein from the same matrix were strikingly similar; (2) protein ions produced by IR-MALDI experienced less fragmentation than those produced by UV-MALDI; and (3) photochemical adducts produced during UV-MALDI were absent in IR-MALDI. These results lead us to speculate on the mechanisms for the ionization process in UV- and IR-MALDI. Because photons with a wavelength of approximately 3 microns are unlikely to effect electronic excitation of the matrix at the irradiance used for MALDI we propose that ionization in IR-MALDI occurs as a natural consequence of the solid-to-gas phase transition induced by the IR irradiation, and involves proton transfer reactions in the intermediate phase between solid and gas. The strikingly similar UV- and IR-MALDI mass spectra leads us to the additional proposal that ionization in UV-MALDI may also be a natural consequence of the phase transition and that electronic excitation may not play a primary role in the ionization process.

A new double lumen balloon catheter for retrograde cerebral perfusion via jugular vein cannulation

A new catheter for retrograde cerebral perfusion (RCP) was developed that can be used to deliver blood directly into the internal jugular vein (IJV) beyond the venous valves at the jugular-subclavian junction and prevent blood from draining into the lower half of the body. This catheter can be inserted into the IJV via a standard puncture technique by use of a 14 Fr sheath. The catheter shaft has two channels for balloon inflation and blood perfusion, respectively. A balloon for occlusion of drainage veins (superior vena cava and azygos vein) is installed at the catheter tip. Side holes, through which oxygenated cold blood is delivered into the IJV, are located 95 mm from the catheter tip. In a mock circulatory study, the pressure at the perfusion line (16-118 mmHg) increased with the increasing flow rate (0-400 ml/min). In clinical application, under circulatory arrest with profound hypothermia, inflation of the balloon effectively reduced blood drainage into the lower half of the body and, consequently, RCP was successfully performed (flow rate, 300-350 ml/min; pressure at the IJV, 15 mmHg). Because all of these procedures were controlled from outside the operative field, RCP by use of this catheter could be useful in distal arch replacement via left lateral thoracotomy.

The dose-response pharmacology of intrathecal sufentanil in female volunteers

The pharmacologic effects of intrathecal sufentanil (ITS) beyond what is clinically administered (10 microg) are not known. We observed 18 healthy, young, adult female volunteers who received 12.5, 25, or 50 microg of ITS in a randomized, double-blind fashion for 11 h. Analgesia was assessed by pressure algometry at the tibia. Respiratory function was assessed by pulse oximetry, respiratory rate, arterial blood gas, the ventilatory response to CO2, and a respiratory intervention score (RIS). The incidence and severity of side effects also were documented. Serum sufentanil levels were measured for 4 h after ITS administration. We found that ITS produced statistically significant changes in algometry, doubling the pressure required to produce moderate pain. However, doses of ITS greater than 12.5 microg failed to produce proportionate increases in the duration or intensity of analgesia. All doses of ITS produced significant respiratory depression, but only the RIS was significantly related to ITS dose. Neither respiratory rate nor sedation reliably predicted hypoxemia. Supplemental oxygen by nasal cannula consistently prevented pulse oximeter readings below 90%. Serum sufentanil concentrations were related to ITS dose in a statistically significant manner, reached clinically significant concentrations, and followed a time course similar to analgesia and measures of respiratory depression. However, there was no significant increase in measured analgesia associated with the increases in serum sufentanil concentrations. We conclude that in our volunteer model of lower extremity pain, administering ITS in doses larger than 12.5 microg does not improve the speed of onset, magnitude, or duration of analgesia and only causes dose-related increases in serum sufentanil concentrations, which may augment respiratory depression.

Cloning and sequencing of a developmentally regulated avian mRNA containing the LEA motif found in plant seed proteins

We report the cloning of a bromodeoxyuridine (BrdU)-sensitive transcript of 918 bp from an immortalized quail heart cell line containing an open reading frame (ORF) of 215 amino acids (aa) (approximately 23 kDa). Analysis of the secondary structure predicts two amphipathic alpha-helices with oppositely oriented amphipathic surfaces at the C-terminus of the protein. Each of the helices contains an LEA (late embryogenesis abundant) consensus sequence (A/TAEKAK/RETKD) which has been previously described only in a group of plant seed-specific proteins. Temporal and spatial distribution patterns of the transcript during chick embryo development were examined by whole-mount in situ hybridization and Northern blot analysis. At H&H (Hamburger and Hamilton, 1951) stages 11-14, the message was expressed strongly in blood islands in the area opaca. At day 5, strong signals were found in the liver primordia, mesonephrons, and nephric duct. Frozen sections of whole mount-stained embryonic liver demonstrated that the message was restricted to developing blood cells. The expression pattern of this transcript suggests that its protein product may be involved in hematopoiesis during avian development.

Expression of avian glypican is developmentally regulated

An avian cDNA homologue of human and rat glypicans has been cloned from a stage 17 chicken heart cDNA library and used to analyze the distribution of this proteoglycan during development by Northern analysis and whole mount in situ hybridization. At stages 7-12, strong signals were detected in the cephalic region of the neural folds, rostral portion of paraxial mesoderm, and newly formed epithelial somites. At stages 20-25, strong expression was observed in the mantle zone of the telencephalon, the apical epidermal ridge and proximal region of developing limb. Transcripts also were found in the truncus arteriosus and arteriovenous-canal region of the heart, but not in the myocardium. This distribution pattern suggests that the avian glypican may be involved in the morphogenesis of limb, somite, heart, and brain. The expression of glypican also overlaps FGFs in limb bud, FGF receptors in heart and somite, and NGF receptors in forebrain. The affinity of heparan sulfate proteoglycans for growth factors and the distribution of the avian glypican are consistent with a role for this molecule in growth factor-mediated signals.

Refolding parameters for the allosteric homodimeric guanylyl cyclase catalytic core from the atrial natriuretic peptide receptor

Protein folding continues to be an important biophysical topic in molecular biology. We report the parameters for successfully refolding the guanylyl cyclase core of the ANP receptor, an allosteric homodimeric enzyme. Urea was a better chaotropic solvent than guanidine HCl, and physiological salt concentrations and pH were needed for optimal recovery of enzymatic activity. Renaturation was more sensitive to alkaline compared to acidic deviations in solvent conditions. The time course of refolding was sigmoidal producing an enzyme with a specific activity of 16,000 pmol cGMP/min/mg using 60 microM concentration of substrate. Additional factors are described in this unusual case of renaturing an allosteric homodimeric enzyme in vitro.

[The role of thoracoscopy in the diagnosis and management of pleural effusion]

To assess the value of thoracoscopy in the diagnosis and management of pleural effusion, 146 patients with pleural effusion of unknown causes had this examination by using fiberoptic bronchoscope the rigid cold light thoracoscope. 127 of these cases were histopathologically diagnosed. 109 had malignant diseases and 18 benign specific diseases. The histologic diagnoses following thoracoscopic biopsy in all the patients were compared with the clinical findings at follow-up, the results showed that the sensitivity was 92.7%, specificity 100.0% and diagnostic accuracy 93.2%. 72 patients with more than moderate volume of pleural effusion were treated with intrapleural talcum powder suspensions (3% 100 ml) under thoracoscopic control, 63 of them obtained complete pleurodesis. The success rates of talc poudrage pleurodesis were 88.1% in 67 cases with malignant effusion (59/67) and 80.0% in 5 cases with benign pleural effusion (4/5). There were only minor postoperative complications: transient fever in 54 cases, local subcutaneous emphysema in 6 and thoracoscopy site tumor seeding in 2. It was shown that thoracoscopy is simple, safe, reliable and practical in the diagnosis of pleural effusion and that talc pleurodesis is a very effective method for controlling refractory pleural effusion transendoscopically.

The guanylyl cyclase core of an atrial natriuretic peptide receptor: enzymatic properties and basis for cooperativity

The enzymatic properties of a cloned atrial natriuretic peptide receptor are described. The renatured catalytic core had maximal activity with Mn2+, and all nucleoside triphosphates inhibited the enzyme competitively. The catalytic specificity of the enzyme was tested directly. The cyclase reaction was specific for guanine, producing cGMP and cyclic deoxyGMP. Surprisingly, deoxyguanylyl cyclase kinetics were classical, unlike the positive cooperativity seen for guanylyl cyclase activity, suggesting that the 2' hydroxyl group of GTP is necessary for the allosteric mechanism.

Mathematical simulation of unidirectional tissue formation: in vitro transanastomotic endothelialization model

In vitro transanastomotic endothelialization was studied using a mathematical model with the Fisher equation. The Fisher equation is a nonlinear parabolic equation which has a cell migration term and a population growth term. The mathematical model was used to simulate recent experiments performed to investigate quantitatively the unidirectional formation of a bovine endothelial cell monolayer in vitro. The two parameters included in the equation were estimated using a trial and error method in which the calculated solutions of the various values of the two parameters are compared with the experimental data and the best fit pair is adopted: one parameter, D, which represents the unidirectional cell migration rate and the other, k, which represents the population growth rate. The calculated solutions fit the experimental data well. We also simulated the healing of a mechanically disrupted endothelial monolayer sheet. The significance of cellular biomechanics in tissue formation and design of tissue-engineered devices is discussed.

Salmonella typhimurium pgtB mutants conferring constitutive expression of phosphoglycerate transporter pgtP independent of pgtC

PgtC is one of the three components of the atypical "two-component" pgt regulatory system. To investigate whether functional PgtC required for the induction of pgtP expression could be bypassed in the signal transduction process, we sought, and succeeded in isolating, intergenic suppressors arising in the low-copy mini-F plasmid, pSJ11, bearing the entire pgt system except for a 168-bp deletion near the end of the pgtC gene. By transport assays, these suppressors were found to confer constitutive pgtP expression. Intriguingly, all five mutations reside near the 5' end of the pgtB gene, at codons 19 and 21. One mutation alters Arg-19 to Gln, two alter Ala-21 to Thr, one alters Ala-21 to Val, and one alters Ala-21 to Ile. Appropriate strains in which the pgtP promoter was fused to lacZ and which bore the pgtB mutations with and without mutations in pgtC and pgtA genes were constructed, and the epistatic relationships of the wild-type pgtC allele, a mutant pgtA allele, and an essentially total deletion of pgtC to the constitutive pgtB mutations were determined. In the mutant strains bearing the Ala-21 --> Ile and Ala-21 --> Val substitutions, the level of constitutive pgtP-lacZ reporter expression was not affected by the presence of the wild-type pgtC allele, nor was it affected by the total absence of PgtC in the case of the Ala-21 --> Val alteration examined; however, in the mutant strains bearing the Ala-21 --> Thr and the Arg-19 --> Gln substitutions, the extent of constitutive pgtP-lacZ reporter expression was markedly enhanced by the presence of wild-type pgtC allele and, in the case of the Arg-19 -->Gln change examined, by the total absence of PgtC as well. These results indicate that PgtC contains no domain necessary for the kinase activity; that PgtB can be activated in the absence of PgtC mutational alterations of the protein itself; and that PgtB and PgtC interact in the signaling process, with PgtC functioning to activate and modulate the kinase activity of Pgtb. In all strains, the replacement of the wild type pgtA allele with a mutant pgtA allele completely abolished expression of the pgtP-lacZ reporter, indicating that functional pgtA is essential for the constitutivity. His-457 of PgtB, a potential site of autophosphorylation, is also required for the constitutivity because its change to Val drastically reduced pgtP-lacZ reporter expression. The structural basis for the activation of the altered PgtB is discussed in terms of putative structure of PgtB in the membrane.

The iontophoresis of fentanyl citrate in humans

BACKGROUND

Iontophoresis is a method of transdermal administration of ionizable drugs in which the electrically charged components are propelled through the skin by an external electric field. This study was designed to determine whether iontophoresis could be used to deliver clinically significant doses of fentanyl in humans and whether there is a charge-dose relation in the delivery of fentanyl by iontophoresis.

METHODS

Five adult volunteers were tested three times on separate days, once receiving passive treatment of 0.0 mA for 2 h (0 mA.min), iontophoresis 1.0 mA for 2 h (120 mA.min), and iontophoresis 2.0 mA for 2 h (240 mA.min) in an open, randomized, crossover design. Respiratory rate, heart rate, blood pressure, and hemoglobin oxygen saturation were monitored throughout the study. Plasma fentanyl concentrations were measured several times before, during, and after iontophoresis. Plasma fentanyl concentrations were measured by radioimmunoassay.

RESULTS

No fentanyl was detected after passive (0.0-mA) fentanyl delivery. The following results were obtained for the 1.0- and 2.0-mA deliveries, respectively. Mean times to detectable concentrations of plasma fentanyl were 33 and 19 min; mean times to maximum concentration were 122 and 119 min; maximum concentrations were 0.76 and 1.59 ng/ml (P = 0.010); mean areas under the curve of the plasma fentanyl concentration versus time relation were 233 and 474 ng.ml-1.min (P = 0.003); and mean elimination half-lives were 354 and 413 min (P = 0.326). Only minor adverse side effects related to iontophoresis occurred. However, typical opioid-related effects occurred frequently in the 1.0- and 2.0-mA administration groups.

CONCLUSIONS

Clinically significant doses of fentanyl can be administered by iontophoresis for delivery periods of 2 h. A charge-dose relation exists after administration with currents of 1.0 and 2.0 mA. Future research into the iontophoresis of fentanyl as a method of potent opioid administration is indicated.

Alcohol, tobacco, diet and the risk of oral cancer: a pooled analysis of three case-control studies

This combined analysis of data from three large case-control studies of oral cancer confirms the important effect of tobacco in the aetiology of the disease. The studies have been conducted in the United States, Italy and China and results for risks associated with tobacco smoking were generally consistent across centres, while those for alcohol were not; increased risks amongst alcohol drinkers were evident in two centres but not in the study conducted in Turin, Italy. In addition, the combined analysis had large enough numbers to analyse the risk of tobacco consumption in non-drinkers. In females these showed increased risks while in males the effect of tobacco alone was weaker. Given the popularity of tobacco smoking, and its consequent high attributable risk in terms of oral cancer it is reassuring, in terms of public health, that cessation will result in a substantial reduction in risk; a 30% reduction in risk for those stopping smoking between 1 and 9 years, and a 50% reduction for those stopping more than 9 years. Although encouraging smokers to stop should be the principal aim, decreases in risk for everyone could be achieved by encouraging high fruit and vegetable consumption.

Buccal absorption of fentanyl is pH-dependent in dogs

BACKGROUND

Analgesia and sedation have been achieved noninvasively by fentanyl administration through the oral and nasal mucosa. In theory, the transmucosal bioavailability and absorption of fentanyl could be improved by converting more fentanyl to the unionized form by adjusting the surrounding pH. The authors tested this hypothesis in dogs.

METHODS

Under general anesthesia, each of six mongrel dogs was given fentanyl on repeated occasions, first intravenously (once), then by application to the buccal mucosa (six times). Buccal fentanyl administration was accomplished by placement of a pH-buffered solution of fentanyl into a specially constructed cell, which was clamped to the dog's buccal mucosa for 60 min. Fentanyl solutions with pHs of 6.6, 7.2, and 7.7 were studied to span a tenfold difference in the unionized fraction of fentanyl. Femoral arterial blood samples were sampled frequently and analyzed for fentanyl using a radioimmunoassay. Peak plasma concentration and the time of its occurrence for each buccal study were noted from the plasma concentration verses time profile. Terminal elimination half-life, bioavailability, and permeability coefficients were calculated using standard pharmacokinetic techniques.

RESULTS

The variables peak plasma concentration, bioavailability, and permeability coefficient increased three- to fivefold as the pH of the fentanyl buccal solution increased and more fentanyl molecules became unionized. There was no difference in terminal elimination half-life after intravenous fentanyl (244 +/- 68 min) or buccal fentanyl administration (pH 7.7, 205 +/- 89 min; pH 7.2, 205 +/- 65 min; pH 6.6, 196 +/- 48 min). In all buccal studies regardless of pH, time to peak plasma concentration occurred within 10 min of removal of the fentanyl solutions from the buccal mucosa.

CONCLUSIONS

The buccal absorption, bioavailability, and permeability of fentanyl are markedly increased as the pH of the fentanyl solution becomes more basic. Most likely, this is because of an increase in the fraction of unionized fentanyl.

Clinical use of low porosity woven ultrafine polyester fiber grafts

A woven fabric graft made of ultrafine polyester fibers (UFPF) (Toray Graft, water porosity: 100 ml/min/cm2:120 mm Hg H2O) was clinically applied in 81 cases (28 thoracic aortic aneurysms, 6 thoracoabdominal aortic aneurysms, 42 abdominal aortic aneurysms, and 5 atherosclerotic obstructions of the peripheral arteries). Eight patients died after surgery due to causes unrelated to the graft. The other 73 patients were in good condition after surgery. For operations requiring extracorporeal circulation, the graft was presealed with human albumin. For the abdominal aortic aneurysms, the graft was preclotted in situ with nonheparinized autoblood after the completion of the proximal anastomosis. It took about 2 min to complete the preclotting. A nonsealed graft was used for the reconstruction of peripheral arteries for the intraaortic balloon pumping procedure. The graft was easy to handle. There was no cut edge fraying problem with the graft in any direction of cutting. Even after presealing, the graft was soft and pliable enough to enable easy adaptation and anastomosis. Just after implantation, bleeding was minimal from the graft wall, anastomotic sites, and suture pores, and it stopped spontaneously. These clinical data showed that the woven UFPF graft exhibited both easy handling despite in spite of low porosity and safe application in the reconstruction of arterial systems even under totally heparinized conditions during extracorporeal circulation.

Development of a vascular prosthesis for a growing child. A graft expandable in vivo

Specially designed vascular prostheses that can be dilated after implantation using a percutaneous transluminal angioplasty (PTA) balloon catheter have been developed. The grafts are made of woven polyester fiber fabrics, the circumferential yarns of which consist of two different types of polyester fiber bundles: One is a straight weak bundle, the other is a strong bundle wound around the former. The graft with an initial diameter of 6 mm could be dilated to 9 mm by luminal inflation of the balloon four to five times at 10 atmospheres (atm) in vitro. After disrupting the weak bundle by the dilatation procedure, the strong bundles were straightened, which maintained the enlarged diameter of the new caliber. Grafts of 6 mm in initial diameter implanted into the thoracic aortas of mongrel dogs for 3 months also could be dilated in vivo by inflating the PTA four to five times at 15 atm, as found in the vitro study. Macroscopic observation revealed that, around the dilated grafts, only a tiny hematoma was formed and nominal subsequent bleeding was observed, which indicated that the dilatation procedure was performed safely. The graft, which enables adaptation of the hydrodynamic property of the graft to the increased blood flow by PTA after implantation, is applicable in a growing child.

Progress in Cleveland Clinic-Nimbus total artificial heart development

A totally implantable, Cleveland Clinic-Nimbus total artificial heart (TAH) uses electrohydraulic energy conversion and an automatic left master-alternate mode control scheme, with a filling sensitivity of 1.0 l/min/mmHg and a maximum output of 9.5 l/min. The TAHs were tested in 12 calves for 1-120 days with normal major organ and blood cell function. Post-operative suppression of platelet aggregation recovered by the second post-operative week. The gelatin-coated pump surface generally was clean without any anticoagulants and free from infection. Embolism, which occurred in two cases, was caused by complications attributable to fungal infection in a Dacron graft and by thrombus formed around a jugular vein catheter. A system with a hybridized microcircuit controller in the interventricular space has been tested successfully in the three most recent cases, with a peak device surface temperature elevation of 6.5 degrees C. Heat effects were confined to the tissues immediately adjacent to the hottest spots. The carbon fiber-reinforced epoxy housing and 60 ml butyl rubber compliance chamber showed good tissue compatibility with a thin, fibrous tissue capsule. The transcutaneous energy transmission system and the internal battery functioned well as designed in the most recent animal implant.

Endothelial cell senescence inhibits unidirectional endothelialization in vitro

We investigated the effects of cellular senescence on unidirectional endothelialization in vitro, simulating the anastomotic endothelialization of vascular prosthesis. The experiments were carried out with three different cumulative population-doubling levels (CPDLs) of bovine aortic endothelial cells (ECs), which have finite life span. Young ECs with 22 CPDL, middle aged with 46, and senescent with 70 at the time of inoculation were used. The effect of aging on unidirectional endothelialization, as well as cellular morphology and proliferative and migratory potentials of isolated cells, were qualitatively and quantitatively analyzed. The unidirectional endothelialization rate was determined by our newly designed method to prepare the square monolayer sheet with linear margins between cell-adhesion and noncell-adhesion regions. The results showed that endothelial cell senescence retarded not only proliferation and migration but also unidirectional endothelialization. Time-lapsed videomicroscopic study of unidirectional endothelialization process revealed that ECs at several rows back from the leading edge represented much slower rate of migration than did the ECs at the leading edge. These findings suggest that high cellular mobility observed for the ECs at the leading edge may result in localized excessive cell replication. Thus, atherosclerotic vessels containing senescent or injured ECs may have limited capability of anastomotic endothelialization.

A functional neointima with regularly arranged smooth muscle cells in a fabric vascular prosthesis transplanted with autologous venous tissue fragments

Regular arrangement of smooth muscle cells underneath an endothelial cell layer was observed in the neointima of a fabric vascular prosthesis treated with new technology to accelerate endothelialization, i.e., transplantation of autologous venous tissue fragments in the graft wall. This finding indicated that the neointima has a vital function as the intima of the blood vessel. A canine left jugular vein was minced and stirred into 20 ml of saline containing 1,000 IU heparin. It was injected with pressure into a fabric prosthesis (4 mm inner diameter [ID], 3.5 cm in length, Water porosity: 4,000 ml) to create the tissue fragmented, heparinized graft. The graft was implanted into the same animal from which the jugular vein was taken. Forty tissue fragmented heparinized (TFH) grafts were implanted in both carotid arteries of 20 dogs and explanted from 1 hr to 400 days after implantation. In this study, the neointimae of the grafts implanted for more than 1 month are analyzed, with a focus on the arrangement of smooth muscle cells in the neointima. A circumferential arrangement of smooth muscle cells with a thin layer of longitudinally arranged cells underneath was seen in the neointimae, which resemble the arrangement of smooth muscle cells in the natural arterial wall. Some areas had a thin smooth muscle cell layer in the longitudinal direction just under the endothelial cell layer. At anastomotic sites, they ran in parallel rows in the longitudinal direction. The authors previously clarified that the smooth muscle cells arrange in parallel rows in the direction of strain caused by tensile stress.(ABSTRACT TRUNCATED AT 250 WORDS)

[Renal autotransplantation and graft replacement for DeBakey IIIb dissecting aneurysm--a case report]

A successfully repaired case, a 53-years old man, who suffered DeBakey IIIb type dissecting aneurysm and renal dysfunction was reported. The right kidney, of which artery was originated from the false lumen, was autotransplanted to the right iliac system to improve the renal blood circulation. Then the descending aorta was segmentally replaced with the prosthesis under profound hypothermia, circulatory arrest and retrograde cerebral perfusion without cross-clamping the aortic arch. Three months later, aortography and catheterization study suggested that the reperfused left kidney resulted in renin-dependent hypertension. Kidney, therefore, was resected to improve blood pressure control. Patient recovered successfully, with no evidence of neurological complication.

Small diameter vascular prostheses with incorporated bioabsorbable matrices. A preliminary study

The authors have designed small diameter vascular prostheses with incorporated matrices that can be absorbed into a growing anastomotic neointima. First, a gelatin-heparin complex was coated on the inner surface of tubular ultrafine polyester fabrics presealed with heat denatured albumin. Second, to control the bioabsorption rate, the prepared grafts were cross-linked with polyepoxy compounds for 3 days (Group I; n = 14) or 5 days (Group II; n = 4). These grafts, 3 mm in diameter and 4 cm long, replaced the carotid arteries of nine mongrel dogs weighing 9.5-14 kg. Six of eight (75%) grafts in Group I were patent when the animals were killed 4 weeks after surgery. Doppler sound examination revealed that the remaining six were patent for 16 weeks. In Group II, three of four (75%) grafts were patent when the animals were killed 8 weeks after surgery. In both groups, scanning electron microscopic study showed neither platelet aggregation nor fibrin formation on the midportion. However, these two groups significantly differed in histology. In Group I, thin anastomotic neointima advanced over the mostly absorbed gelatin-heparin complex layer. Connective tissue was well formed around the polyester scaffold. In contrast, thick neointima advanced over the gelatin-heparin complex layer that still remained on the luminal surface in Group II. These results suggest that the gelatin-heparin complex, when cross-linked adequately, could simultaneously function as a temporary antithrombogenic surface and as an excellent substructure of an anastomotic neointima.

A case-control study of oral cancer in Beijing, People's Republic of China. Associations with nutrient intakes, foods and food groups

A case-control study of oral cancer was conducted in Beijing, People's Republic of China to examine the association between dietary nutrient intake and risk of oral cancer, both in terms of estimated intake of nutrients and micro-nutrients, and in terms of specific foods and food groups. The study was hospital-based and controls were hospital in-patients matched for age and sex with the cases. The response rate for cases and controls was 100% and 404 case/control pairs were interviewed. The results suggest that increased protein and fat intake are related to a decreased risk of oral cancer. Carbohydrate intake, however, showed a moderate increased risk for oral cancer. Total carotene intake and carotene intake from fruits and vegetables are inversely associated with risk of oral cancer. A similar pattern was observed for dietary vitamin C intake. Dietary fibre derived from fruits and vegetables showed a strong negative association with oral cancer risk, but fibre derived from other sources did not exhibit any protective effect. At the level of foods and food groups, increased consumption of fresh meat, chicken and liver was significantly associated with a reduction in oral cancer risk: the tests for trend were all statistically significant at the P < 0.01 level. Consumption of common carp, hairtail, shrimp and lobster were also associated with decreased risk. Risk was found to increase with increasing consumption of millet and corn bread (P < 0.01) but to decrease with increasing consumption of rice (P < 0.01). Increased consumption of grapes, bananas, oranges, tangerines, peaches and pears were associated with reduced risk.(ABSTRACT TRUNCATED AT 250 WORDS)

[Development of a method to prevent degenerative changes of the vein graft for arterial reconstruction]

Autologous vein graft is frequently used for arterial reconstruction in vascular surgery. Its' long-term patency rate, however, is low because of the degenerative changes of the vein wall. Of the basis of our hypothesis that the degenerative changes are mainly caused by an over-distension of vein wall in arterial system, in this study, autologous vein grafts of rabbit (N = 56) were implanted in the carotid arteries. To prevent overdistension, some of the grafts were covered with prosthesis which was made of microporous, compliant biodegradable polyurethane and were compared with those without prosthesis. The integrity of the architecture of the vein wall covered with prosthesis was well preserved at 6 weeks after implantation, where the biodegradation of prosthesis induced an optimal arterialization of the vein grafts. The results indicate that this method may prevent the degenerative changes of vein wall such as fibrosis and intimal hyperplasia, which would cause poor long-term patency of vein graft used for arterial reconstruction.

Overexpression of dimeric guanylyl cyclase cores of an atrial natriuretic peptide receptor

Using a bacterial expression system, large amounts of the catalytic core of an atrial natriuretic peptide receptor guanylyl cyclase were produced and purified. After refolding the protein from a buffer containing urea, the enzyme had positively cooperative kinetics with a Hill coefficient, nH = 1.42 +/- 0.08. Size exclusion chromatography and denaturing polyacrylamide gel electrophoresis demonstrated that the enzyme is composed of homodimers with interacting catalytic sites.

Experimental study on limitations of anastomotic endothelialization of vascular prostheses

We studied the effect of endothelial cell (EC) senescence on proliferation, migration, and endothelialization in vitro using a culture model. Two generations of cultured bovine aortic ECs were used. The results showed that 1) the senescent ECs had much reduced rates of proliferation, migration, and endothelialization in vitro, and 2) that the young ECs at the leading edge gradually developed morphology similar to that of the senescent ECs as endothelialization proceeded. Computerized videomicroscopic observation revealed that the ECs at the leading edge had higher motile activity than the ECs at the back. This suggests that the ECs at the leading edge, and circumvented from contact inhibition, may proliferate much more frequently than the ECs at the back. Localized cellular aging may result in decelerated or incomplete endothelialization, as found clinically.

Healing process of vascular prostheses seeded with venous tissue fragments

Rapid neointima formation in fabric vascular prostheses seeded with autologous venous tissue fragments was examined. A piece of peripheral vein was minced into small fragments and stirred into 20 ml of saline. This tissue suspension was sieved through the wall of Dacron prostheses. The prostheses implanted in the descending aortae of dogs showed extremely rapid healing of the neointima. Endothelial cells lined the entire luminal surface within 14 days. There was no difference in the healing process between the area near anastomotic sites and the center.

Control of cellular orientation in two-dimensional tissue formation. Surface topologic effect of collagen fibers on endothelialization

The authors studied the effect of polymorphous states of collagen on in vitro cellular orientation of bovine aortic endothelial cells (ECs). Little orientation of adherent ECs was observed on a nonoriented collagen coated surface, irrespective of culture period. Only ECs that adhered to fiber bundles 10 microns in diameter exhibited cellular elongation or alignment. The collagen membrane with highly oriented fine fibers provided no cellular alignment for ECs in sparse culture. Resultant confluent monolayers, however, were characterized by cellular orientation, suggesting that surface microtopology of collagen induces cellular orientation on incubation. Control of cellular orientation would be an elementary requirement for cell seeding technology leading to hybrid artificial organs.

Endothelialization on various segmented polyurethanes: cellular behavior and its substrate dependency

Endothelialization on artificial substrates is essential for providing vital function to artificial and hybrid vascular prostheses. The authors studied fundamental behaviors of endothelial cells (EC), including adhesion, spreading, migration, and growth, on various segmented polyurethanes (SPU) with a wide variety of wettability. Endothelialization has a synergistic action on these cellular behaviors that was quantitatively evaluated by phase contrast microscopy. Surface characteristics of SPU were analyzed by contact angle measurement and X-ray photoelectron spectroscopy. Adhesion, spreading, migration, growth, and endothelialization in vitro of bovine aortic EC on relatively hydrophobic SPU exceeded those on both a hydrophilic SPU, and a very hydrophobic siliconized one. Minimal interaction with EC was found for hydrophilic SPU. Adherent cells tended to be delaminated from siliconized SPU in a later culture period. The addition of a peptidyl antagonist of adhesive protein receptor inhibited adhesion of EC on SPU. These results suggest that surface characteristics, possibly regulating adsorption of adhesive proteins, are important factors in the development of vascular SPU prostheses.

In vitro model of endothelialization at anastomotic sites

Endothelial cell (EC) migration from native arteries to vascular prostheses is one of the most important healing processes of implanted artificial grafts, which results in endothelial cell coverage of the luminal surface of the graft. This article presents an in vitro model of endothelialization at the anastomotic site, which can provide cellular level information on morphologic reconstruction, and its substrate dependency. Test materials included polyethylene terephthalate (PET), segmented polyurethanes (SPUs), and glass with or without protein precoating (collagen, fibronectin, and albumin). In vitro endothelialization on these substrates was quantitatively determined by phase contrast microscopy. The results obtained show: 1) The fastest endothelialization rate was found on PET, followed by relatively hydrophobic SPU, and glass--the slowest was on hydrophilic SPU; and 2) Precoating with proteins drastically altered the cellular behaviors; collagen greatly enhanced endothelialization in vitro, followed by fibronectin. Precoating by albumin, however, greatly retarded endothelialization. The present study strongly suggests that unidirectional endothelialization at the anastomotic sites is controlled by the surface characteristics of graft materials.

[A case of "chronic expanding hematoma", with an intrapulmonary fresh hemorrhage resected 25 years after thoracic injury]

A case of a 60-year-old man who had a chronic expanding hematoma with an intrapulmonary fresh hemorrhage in the right thorax is reported. He suffered blunt trauma of his right thorax in a traffic accident 25 years ago. He has no symptoms and signs after the accident. But he had hemoptysis twice and he was taken to our hospital. He underwent the resection of the chronic expanding hematoma and right lower lobe of the lung. The surgical specimen consisted of the hematoma measuring 17 x 13 x 6 cm. The chronic expanding hematoma contained aseptic brownish muddy substances. The patient recovered without complications and hemoptysis. Chronic expanding hematomas occur in many locations, often simulating neoplasms. Although the mechanism of chronic expanding hematoma is unclear, the self-perpetuating expanding nature of the lesion may appear to be due to the irritant effects of blood and its breakdown products, causing repeated exudation or bleeding from capillaries in the granulation tissue.