Biomedical subjects

C C Wu

Publications and source records attributed to C C Wu.

At least 145 records · Page 8Linked to original sources

PubMed1999

Role of nitric oxide and K+-channels in vascular hyporeactivity induced by endotoxin.

This study was to investigate possible mechanisms associated with vascular hyporeactivity to vasoconstrictor agents in rats with endotoxaemia. Wistar-Kyoto rats were anaesthetised and injected with endotoxin [E. coli lipopolysaccharide (LPS); 10 mg/kg, i.v.] for 4 h. Pressor responses to noradrenaline (NA; 1 microg/kg, i.v.) were determined prior to and at every hour after LPS injection. After the in vivo experiment, rat thoracic aortas were excised and prepared as rings 3-4 mm in width. The endothelium was mechanically removed to evaluate K(+)-channel activity and the effects of nitric oxide (NO) on the vascular smooth muscle. Our results demonstrated that: (1) injection of LPS caused a significant fall in blood pressure and a severe vascular hyporeactivity to NA in the anaesthetised rat, (2) the relaxation induced by the K(+)channel opener cromakalim was greater in rings obtained from endotoxaemic rats and this enhanced relaxation was partially inhibited by pretreatment of these rings with 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), an inhibitor of the NO/cGMP pathway, (3) endotoxaemia for 4 h was also associated with a profound vascular hyporeactivity to NA ex vivo and this vascular hyporesponsiveness was partially inhibited by ODQ, tetraethylammonium (TEA, a non-selective inhibitor of K(+)-channels) and charybdotoxin [CTX, a selective inhibitor of large conductance calcium-activated K(+)- channels (BK(Ca))], but not by apamin, and (4) the combination of TEA or CTX with ODQ completely restored that vascular responsiveness to normal. These results suggest that activation of BK(Ca) and overproduction of NO in the vascular smooth muscle simultaneously contribute to vascular hyporeactivity to vasoconstrictor agents in endotoxaemia.

Animals↗

PubMed1999

Tetramethylpyradizine prevents inducible NO synthase expression and improves survival in rodent models of endotoxic shock.

This study is to investigate the possible mechanism of beneficial effects of tetramethylpyrazine (TMP) on endotoxic shock which we showed in our preliminary study (Liao et al. 1998; Proc Natl Sci Counc Repub China B 22:46-54). Here, we have confirmed the beneficial effects of TMP on the hypotension, vascular hyporeactivity to noradrenaline (NA), release of tumour necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) in a rat model of circulatory shock induced by bacterial endotoxin (E. coli lipopolysaccharide, LPS). In addition, we further examined the expression of inducible NO synthase in the lung and in the aorta from these rats and evaluated the effect of TMP on the 36-h survival rate in a murine model of endotoxaemia. Male Wistar-Kyoto rats were anaesthetised and instrumented for the measurement of mean arterial pressure (MAP) and heart rate (HR). Injection of LPS (10 mg kg(-1), i.v.) resulted in an acute fall followed by a substantial fall in MAP within 4 h and an increase in HR. In contrast, animals pretreated with TMP (10 mg kg(-1), i.p.; at 30 min prior to LPS) maintained a significantly higher MAP but the tachycardia was further enhanced at 1-2 h when compared to rats given only LPS (LPS rats). The pressor effect of NA (1 microg kg(-1), i.v.) was also significantly reduced after the treatment of rats with LPS. Similarly, the thoracic aorta obtained from rats at 4 h after LPS showed a significant reduction in the contractile responses elicited by NA (1 microM). Pretreatment of LPS rats with TMP partially, but significantly, prevented this LPS-induced hyporeactivity to NA in vivo and ex vivo. The injection of LPS resulted in a bell-shaped change in plasma TNF-alpha level which reached a maximum at 1 h, whereas the effect of LPS on the plasma level of nitrate (an indicator of NO formation) was increased in a time-dependent manner. This increment of both TNF-alpha and nitrate levels was significantly reduced in LPS rats pretreated with TMP. Endotoxaemia for 4 h caused a significantly increased protein expression of iNOS in the lung and the aorta. In LPS rats pretreated with TMP, iNOS protein expression in lung and aorta homogenates was attenuated by 75+/-3% and 57+/-6%, respectively. In addition, the lack of evidence of pressor effect of TMP on rats with endotoxaemia for 4 h suggested that TMP inhibits the induction of iNOS rather than directly inhibiting NOS activity. Treatment of conscious ICR mice with a high dose of endotoxin (60 mg kg(-1), i.p.) resulted in a survival rate of only 15% at 36 h (n=20). However, therapeutic application of TMP (10 mg kg(-1), i.p.; at 0, 6, 15 and 24 h after LPS) increased the 36 h survival rate to 55% (n=20). Thus, TMP inhibits the expression of iNOS and mitigates the delayed circulatory failure caused by endotoxic shock in the rat. In addition, TMP also improves survival in a murine model of severe endotoxaemia.

Animals↗

PubMed1999

Effect of reaming bone grafting on treating femoral shaft aseptic nonunion after plating.

Rigid intramdullary nailing with cancellous bone grafting provided by intramedullary reaming was prospectively used to treat femoral shaft aseptic nonunions after plating. Indications for this technique were a femoral shaft nonunion with an inserted plate, no previous infection sign in the treatment course, less than 1.5 cm shortening, and no segmental bony defects. After the plate was removed, a flexible guidewire was inserted antegradely. The local wound was closed, and intramedullary reaming was done as widely as possible until some resistance to it occurred. Finally, a rigid intramedullary nail was inserted. Twenty-four consecutive patients were treated with this regimen, and 21 were followed-up for at least 1 year (range 1-5 years). All 21 nonunions healed with a union rate of 100% (21/21). The time to union was 4.5 +/- 1.0 months. There were no significant complications. We conclude that for indicated cases, reaming bone grafting is a very effective technique and avoided donor site morbidity. Therefore, whenever possible, this technique could be considered first.

Adult↗

PubMed1999

The effects of dyslipidemia on left ventricular systolic function in patients with stable angina pectoris.

Large-scale clinical trials have shown that long-term treatment with lipid-lowering therapy results in a significant reduction in the occurrence of heart failure among patients with coronary artery disease without previous evidence of congestive heart failure, suggesting dyslipidemia may have an adverse effect on left ventricular performance. To examine whether dyslipidemia has a detrimental effect on left ventricular systolic function and whether this effect is dependent on the corresponding severity of coronary atherosclerosis, 114 consecutive patients with stable angina and a positive exercise thallium-201 myocardial perfusion single-photon emission computed tomography were studied. All patients underwent measurement of serum lipid profiles, right-sided heart catheterization, left ventriculography, and selective coronary arteriography. Mean serum levels of total cholesterol and triglycerides were 4.5 and 1.4 mmol/l, respectively. In univariate analysis, a significant positive correlation between serum high-density lipoprotein (HDL) cholesterol and left ventricular ejection fraction (LVEF) (r = 0.49, P<0.0001) was found. Patients in the lower tertile of serum HDL cholesterol had a significantly lower mean LVEF than those in the upper tertile (55.9+/-15.2 vs. 72.8+/-6.8%, P<0.0001). Stepwise multiple linear regression analysis revealed that LVEF significantly correlated with HDL cholesterol (P<0.0001), the Gensini score (P = 0.008), and diabetes mellitus (P = 0.08) (r = 0.55, P<0.0001). In subgroup analysis of patients with angiographically normal coronary arteries, serum HDL cholesterol was still significantly associated with LVEF. The present study demonstrated an independent association between low HDL cholesterol and subclinical left ventricular systolic dysfunction in Chinese patients with stable angina whose serum levels of total cholesterol and triglycerides were relatively low. Moreover, this correlation remained significant even in patients with normal coronary angiograms, suggesting HDL cholesterol might influence left ventricular systolic performance through extra-atherosclerotic mechanisms.

Aged↗

PubMed1999

Cyclic GMP regulates cromakalim-induced relaxation in the rat aortic smooth muscle: role of cyclic GMP in K(ATP)-channels.

Recent studies have shown that nitric oxide (NO) modulates K+-channel activity which play an important role in controlling vascular tone. The formation of cyclic guanosine 3',5'-monophosphate (cyclic GMP) has also been recognized to be associated with the vasodilatory effect of NO. Both cyclic GMP and NO increase whole-cell K+-current by activating Ca2+-activated K+-channels (K(Ca)-channels). Here, we show evidence that activators of soluble guanylyl cyclase sodium nitroprusside or 3-morpholino-sydnonimine (SIN-1), and an analogue of cyclic GMP 8-bromo-cyclic GMP enhance the relaxation induced by cromakalim which is blocked by glibenclamide (a specific inhibitor of ATP-sensitive K+-channels [K(ATP)-channels]), and partially attenuated by methylene blue (an inhibitor of cyclic GMP formation). However, this is not due to the increase of cyclic GMP level by cromakalim itself because the relaxation induced by cromakalim is not associated with the changes of cyclic GMP level formed in the aortic smooth muscle. Thus, it is most likely that cyclic GMP also modulates activity of K(ATP)-channels, in addition to K(Ca)-channels, in the rat aorta.

Adenosine Triphosphate↗

PubMed1999

Amplification and cloning of infectious bursal disease virus genomic RNA segments by long and accurate PCR.

Improved methods of reverse transcription, polymerase chain reaction (PCR) amplification, and cloning of full-length coding region of both strands of infectious bursal disease virus (IBDV) variant strain E genome were developed. Denaturation of IBDV RNA by heat in the presence of primers and use of a reverse transcriptase lacking RNase-H activity produced full-length coding region and partial non-coding region cDNA copies of the viral genomic segments. Digestion of the RNA component of RNA-cDNA hybrids by RNase-H followed by long and accurate PCR (LA-PCR) amplification of IBDV cDNA in a single step resulted in the synthesis of 3182 base-pairs (bp) of segment A and 2777 bp of segment B cDNA copies of IBDV genome. The resulting amplicons were successfully cloned and sequenced revealing their identity of IBDV. The LA-PCR method can be utilized for the amplification and cloning of the other IBDV strains or isolates and will greatly enhance the availability of sequence information or infectious cDNA copies of IBDV.

Animals↗

PubMed1999

Immunological characterization of two major secreted forms of recombinant hepatitis B virus e antigens.

Plasmids containing PCR-amplified hepatitis B virus e antigen (HBeAg) genes (HBeAg-MV and HBeAg-SV) were constructed and expressed in E. coli strain DH5alpha. The induced intracellular glutathione S-transferase (GST) fusion proteins of HBeAg-MV and HBeAg-SV were recovered and purified from bacterial lysates by affinity chromatography with glutathione-sepharose beads. The HBeAg-MV protein contained an additional 19 amino acids at its amino terminus. These two proteins were specifically cleaved from GST by the protease factor Xa and recognized by a monoclonal antibody against HBeAg. HBeAg-MV and HBeAg-SV were found to be the two major components of the post-modified HBcAg during viral infection. The antigenic specificities of the fusion and purified HBeAgs (factor Xa-digested) were confirmed by the Abbott HBe enzyme immunoassay (EIA) detection system. Sera from patients with confirmed hepatocellular carcinoma (HCC) specifically reacted only with HBeAg moiety of fusion proteins. HCC sera bound more strongly to the HBeAg-SV protein than to the HBeAg-MV one. This indicates that HBeAg-SV is either more antigenic than -MV or is the major target protein for the elicitation of antibody production after HBV infection. Thus, the two recombinant HBeAgs expressed and obtained in this study are appropriate immunological agents for the diagnostic detection of hepatitis B virus infection in humans.

Blotting, Western↗

PubMed1999

Metabolites of diallyl disulfide and diallyl sulfide in primary rat hepatocytes.

The objectives of this study were to analyse and identify the metabolites of diallyl disulfide (DADS) and diallyl sulfide (DAS) in primary rat hepatocytes prepared by collagenase perfusion. According to the results, allyl mercaptan (AM) and allyl methyl sulfide (AMS) were the metabolites of DADS. The highest amount of AMS (0.93 +/- 0.08 microg/ml at 90 min) was much less than that of AM (46.2 +/- 6.6 microg/ml at 60 min). Combined with the Purge and Trap using a gas chromatography-mass spectrometry (GC-MS) system, it is very useful to detect the trace amounts of metabolites in primary rat hepatocytes. Results also showed that AMS was a metabolite of DAS. The highest amount of AMS in the extracellular fluid of hepatocytes was 0.63 +/- 0.16 microg/ml at 30 min of incubation.

Allyl Compounds↗

PubMed1999

Alterations in ultrasonic backscatter during intra-aortic balloon counterpulsation support in patients with acute myocardial infarction.

Alterations of ultrasonic backscatter parameters have been evident in humans with myocardial infarction or ischemia. The backscatter variability could be restored in ischemic or stunned myocardium after reperfusion. The aims of this study were to determinate changes in regional myocardial ultrasonic backscatter during intra-aortic balloon counterpulsation (IABP) support in patients with acute myocardial infarction (AMI), and to evaluate whether backscatter imaging could be a functional guide of IABP support. A total of 9 patients with AMI were investigated during IABP support with a two-dimensional (2-D) ultrasonic backscatter imaging approach for parasternal short-axis view. Coronary angiography was performed in 6 of the 9 patients. A total of 21 vessel territories were studied in different modes of IABP support: 1:1, 1:2 and standby. Restoration of cyclic variation of backscatter after IABP support was demonstrated in 10 vessel territories. Failure of restoration of cyclic variation of backscatter after IABP support was noted in 6 vessel territories with severe coronary lesions (total or nearly total occlusion) or scar tissue. No changes of the ultrasonic backscatter were found in nonischemic vessel territories with patent coronary arteries or TIMI III coronary flow. In addition, the wall motion score did not change significantly with different IABP support. These results suggest that IABP could restore the cyclic variation of backscatter in ischemic myocardium. Myocardial anisotropy may play an influential role in the alterations of ultrasonic backscatter. We propose that ultrasonic backscatter could be a noninvasively functional guide of IABP use in patients with AMI.

Aged↗

PubMed1999

The transport rate of cholera toxin B subunit in the retinofugal pathways of the chick.

This study investigated the transport rate of the tracer, cholera toxin B subunit, within the retinofugal pathway of the chick hatchlings. Following intraocular injections, the chicks were allowed to survive for various time-periods. The immunoreactivity of cholera toxin B subunit was then examined in the retinofugal pathways. Two hours post-injection, retinal ganglion cells began to take up the tracer and transport it to the most rostroventral portion of the optic tectum. After a 4 h survival period, the labeled retinal axons progressively innervated all retinofugal targets. Within the tectum, the labeling density varied from layer to layer with heavily labeled terminals in layer 5b, less label in layer 7 and the most diffuse label in layers 2-4. Scattered labeling was seen in the nucleus dorsolateralis anterior thalami, pars lateralis, the nucleus geniculatus lateralis, pars ventralis, the nucleus basal optic root, the nucleus lateralis anterior thalami, and the pretecal lentiformis nucleus of mesencephalon. After 6- and 8 h survival periods, increased labeling was seen in all retinofugal nuclei. There were increased numbers of retinal terminals in all retinorecipient layers of the tectum. It was noted that some of the retinal axons "overshot" into layers deeper than layer 7. In addition, retinal projections were found scattered throughout the ipsilateral nucleus basal optic root. Maximal labeling in all retinofugal targets was observed at a 10 h survival period. The present study suggests that cholera toxin B subunit can be used to trace retinal axons along their retinofugal paths up to the small terminal zones at a rate of 4.25 mm/h or 102 mm/day. Also, evidence of synchronous retinal terminations in layers 5b and 7 indicates that the transport of cholera toxin B subunit is independent of axon diameters of retinal ganglion cells. Finally, given the changing status of the embryo, the rapid transport of cholera toxin B subunit can be applied for tracing developing pathways.

Animals↗

PubMed1999

Higher level of plasma nitric oxide in spontaneously hypertensive rats.

We had detected a slightly, but significantly, higher level of plasma nitrite/nitrate in the spontaneously hypertensive rat (SHR) by using the nitric oxide (NO) analyzer (Sievers 280 NOA), which converts nitrate (including nitrate converted from nitrite) to NO. Here, we examined whether the release of NO from protein-bound dinitrosyl nonheme iron complexes (DNIC) contributes to the elevated plasma nitrate level in the SHR. The SHR and their genetic normotensive controls, Wistar-Kyoto rats (WKY), were anesthestized and cannulized for monitoring blood pressure, collecting a blood sample, and the administration of endotoxin (lipopolysaccharide [LPS]). The nitrate levels (an indicator of NO formation) in the plasma and the aorta were measured by an NO analyzer. In addition, the relaxation of acetylcholine (ACh) in the presence or absence of N(omega)-nitro-L-arginine methyl ester (L-NAME) was also examined in thoracic aortae obtained from both strains. The slight, but significant, increase of basal nitrate levels in the plasma and aorta were observed, and the former was further enhanced in SHR treated with LPS for 3 h. In vitro, the ACh-induced relaxation was attenuated in the aortae obtained from SHR. However, this difference between SHR and WKY (without LPS treatment) was abolished by treatment of rings with L-NAME (30 micromol/L), suggesting that an impairment of NO formation was observed in the SHR. After rats were treated with LPS for 3 h, the ACh-induced relaxation was reduced in the WKY, but not in the SHR. In addition, a 10-fold increase of L-NAME was needed to abolish the difference in ACh-induced relaxation between SHR and WKY, indicating an expression of inducible NO synthase in both strains treated with LPS. We suggest that the elevated plasma NO level in SHR may be due to the release of NO from DNIC in the vascular bed to combat the hypertensive state.

Acetylcholine↗

PubMed1999

Mesohepatectomy for centrally located hepatocellular carcinoma: an appraisal of a rare procedure.

BACKGROUND: For centrally located hepatocellular carcinoma (HCC), extended major hepatectomy is usually recommended, but the risk of postoperative liver failure is high when liver function is not sound. Mesohepatectomy (en bloc resection of Goldsmith and Woodburne's left medial and right anterior segments or Couinaud's segments IV, V, and VIII) is a rare procedure, so its role in treating HCC is unclear. STUDY DESIGN: We retrospectively reviewed 364 patients who underwent a curative resection for HCC. Among them, 15 patients were treated by mesohepatectomy. Their nontumorous liver revealed cirrhosis in 11 and chronic hepatitis in 4. The mean tumor diameter was 12.8 cm. In 10 of the 15 patients, HCC also invaded adjacent organs. The operative results of another 25 patients with different disease extent who underwent extended major hepatectomy were compared. RESULTS: The hepatic inflow occlusion time for mesohepatectomy was longer than for extended hepatectomy (p = 0.01). The mean operative blood loss, amount of blood transfusion, operating time, and postoperative hospital stay in the mesohepatectomy group were 2,450 mL, 1,100 mL, 7.9 hours, and 14.9 days, respectively. In the extended-hepatectomy group, the values were 1,863mL, 768mL, 5.8 hours, and 16.8 days, respectively (all p>0.05 compared with mesohepatectomy). No patient died after mesohepatectomy, but after extended hepatectomy there was one death from liver failure. The Union Internationale contre le cancer (UICC) TNM stages of patients who underwent mesohepatectomy were as follows: stage II in 1, stage III in 4, and stage IVA in 10. All patients who underwent extended hepatectomy presented with stage IVA disease. The 6-year disease-free and actuarial survival rates after mesohepatectomy were 21% and 30%, respectively. The 6-year disease-free survival rate after extended hepatectomy was 9% (p = 0.11 compared with mesohepatectomy). CONCLUSION: Although mesohepatectomy is time-consuming, it is justified for selected patients with centrally located large HCC in a diseased liver.

Adult↗

PubMed1999

YC-1 potentiates nitric oxide-induced relaxation in guinea-pig trachea.

1. The effects of YC-1 (3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole) on tension, levels of cyclic GMP and cyclic AMP were investigated in guinea-pig trachea. We especially studied the combined effect of YC-1 with exogenous or endogenous nitric oxide on these parameters. 2. YC-1 at the concentration 3 or 10 microM, which caused only minor effect by itself, elicited concentration-dependent potentiation of sodium nitroprusside (SNP)-induced tracheal relaxation. This relaxation of YC-1 with SNP was reversed by ODQ. 3. Relaxant responses to electric field stimulation (EFS) in the presence of indomethacin, atropine, guanethidine, alpha-chymotrypsin and histamine were also markedly increased by YC-1 (10 microM). In the presence of L-NAME or ODQ, the relaxant effects to EFS were attenuated and the following addition of YC-1 did not further enhance relaxation. 4. YC-1 (10 microM) or SNP (0.3 microM) alone did not induce significant elevation of cyclic GMP levels in the presence of IBMX, whereas simultaneous application of both compounds markedly elevated the cyclic GMP accumulation. In contrast, the cyclic AMP levels were not altered even at the combination of YC-1 and SNP. Additionally, YC-1 also affected cyclic GMP metabolism, since it inhibited the activity of phosphodiesterase type V in human platelets. 5. YC-1 (30 microM) did not scavenge superoxide anion and had no effect on the removal of superoxide anion by superoxide dismutase in a xanthine/xanthine oxidase system. 6. In conclusion, these results indicate that although YC-1 elicits negligible relaxation of guinea-pig trachea by itself, it can potentiate the relaxant responses of exogenous or endogenous NO. This synergistic response of YC-1 is via the elevation of cyclic GMP contents.

Animals↗

PubMed1999

Hepatitis viral status in patients undergoing liver resection for hepatocellular carcinoma.

BACKGROUND: Hepatitis B and C viruses are the main causative agents of hepatocellular carcinoma (HCC). The influence of hepatitis viral status on liver resection for HCC remains undetermined. METHODS: Patients who underwent curative resection for HCC were divided into four groups: group 1, seronegative for hepatitis B surface antigen (HBsAg) and antihepatitis C antibody (HCVAb); group 2, seropositive for HBsAg only; group 3, seropositive for HCVAb only; and group 4, seropositive for HBsAg and HCVAb. The clinicopathological characteristics and surgical results of the four groups were compared. Resection of HCC was determined according to liver functional reserve and tumour extent. RESULTS: There were 40, 131, 70 and 20 patients in groups 1, 2, 3 and 4 respectively. Due to patient selection bias, there were significant differences in some background features, resectional extent and pathological characteristics among the four groups. Postoperative morbidity and mortality, as well as the Union Internacional Contra la Cancrum tumour node metastasis stages, did not differ. Patients in group 1 had a higher disease-free survival rate than those in group 2 (P = 0. 02). The actuarial survival rates of patients in groups 2 and 4 were lower than those of groups 1 and 3. CONCLUSION: With careful patient selection, the hepatitis viral status does not influence the surgical risks of hepatectomy for HCC. After liver resection for HCC, the long-term survival rate of patients seronegative for HBsAg is greater than that of patients seropositive for HBsAg.

Aged↗

PubMed1999

Induction of the delayed footpad and wattle reaction to killed Staphylococcus aureus in chickens.

Two experiments were conducted to induce the delayed footpad reaction (DFR) to killed Staphylococcus aureus antigen. In Experiment 1, tracheal, cloacal, and choanal swabs were collected from chickens prior to sensitization with S. aureus to determine the carrier status of S. aureus. The second experiment compared the DFR to the delayed wattle reaction (DWR). Chickens were subjected to single or multiple sensitizations in the neck with S. aureus antigen between 4 and 6 wk of age. One week later, birds were challenged with S. aureus either in the right footpad or wattle. The left footpad or wattle was injected with PBS. The thicknesses of the footpad or the wattle were measured up to 96 h postchallenge. The recoveries of S. aureus from the choanal slit and trachea were significantly higher than that of the cloaca (P < 0.001). Birds of Experiment 1 showed a significant DFR (P < 0.0001) following intradermal challenge with killed S. aureus that was sustained through 48 h postchallenge with no difference in the DFR between carrier and noncarrier birds. In Experiment 2, the thicknesses of the footpad and wattle were significantly increased following challenge with S. aureus (P < 0.0001), with the footpad showing a greater response than the wattle (P < 0.001). Three sensitizing dosages, as compared to two dosages, resulted in a less pronounced DFR and DWR (P < 0.02). These results indicate that the DFR can be used as a delayed reaction model in the study of staphylococcosis in poultry.

Animals↗

PubMed1999

Evaluation and validation of ureteric jet index by glomerular filtration rate.

RATIONALE AND OBJECTIVES: Ureteric jet index (UJI), a newly developed technique derived from color Doppler ultrasonography, may hold promise in evaluating renal function because of its ability to evaluate individual renal function and the use of nonionizing radiation. To assess the usefulness of UJI, the authors in this study analyzed the relation between UJI and the glomerular filtration rate (GFR). METHODS: Fifteen adult patients with a wide range of renal function were included in this study. Subjects were well hydrated before color Doppler ultrasonography examinations. The UJI formula was: Vmean (average jet velocity) x D (jet duration) x F (jet frequency). GFR was calculated by the radionuclide method. Correlations between UJI, serum creatinine, and GFR were analyzed. RESULTS: Ureteric jet index had only a fair correlation with GFR. The coefficient of correlation value was 0.61, and the standard error of estimate of GFR was 17.9 mL/min. CONCLUSIONS: With the measurement of UJI, color Doppler ultrasound can provide both structural images and individual renal function information. It could substitute for a renal scan in determining individual renal function when a radionuclide examination is unavailable. Even if a renal scan were available, UJI can play a valuable role in the ultrasound examination of patients with suspected impaired renal function, providing further assessment of individual renal function.

Adult↗

PubMed1999

High success rate with exchange nailing to treat a tibial shaft aseptic nonunion.

OBJECTIVE: To investigate the effects of tibial exchange nailing in treating a tibial shaft aseptic nonunion and to establish optimal indications for using this technique. DESIGN: Prospective, consecutive. SETTING: University hospital. METHODS: Twenty-five consecutive tibial shaft aseptic nonunions were prospectively treated with the exchange nailing technique. Indications for this procedure were a tibial shaft aseptic nonunion that had previously been treated with an inserted nonreamed or reamed intramedullary nail, displayed less than one centimeter of shortening, was with or without rotational or angular deformity, exhibited no segmental bony defects, and was anatomically suited for conventional or locked reamed intramedullary nail stabilization. The marrow cavity was reamed as extensively as possible, and a rigid intramedullary nail with stable fixation was inserted. RESULTS: During a follow-up period of two to four years (median thirty-two months), twenty-four nonunions healed, on average, in four months (range three to six months). The one remaining nonunion healed four months after a cancellous bone grafting procedure. No wound infection or malunion was noted. CONCLUSION: Because of its high union rate, low complication rate, and simplicity of method, we believe that the exchange nailing technique should be considered preferentially for all indicated cases.

Adolescent↗

PubMed1999

Treatment of femoral neck nonunions with a sliding compression screw: comparison with and without subtrochanteric valgus osteotomy.

BACKGROUND: The aim of this prospective study was to investigate and compare the results of treatment of femoral neck nonunions using a sliding compression screw (SCS) with and without subtrochanteric valgus osteotomy (SVO). METHODS: Thirty-two consecutive patients with femoral neck nonunions, which sustained no osteonecrosis of the femoral head based on bone scan study, were prospectively treated with SCS with (21 patients) or without (11 patients) SVO. The indication for SCS with SVO was a femoral neck nonunion with leg shortening of more than 1.5 cm. SCS without SVO was for leg shortening of less than 1.5 cm. RESULTS: Seventeen patients with osteotomy and nine patients without osteotomy were followed for at least 2 years (range, 2-8 years). All femoral neck fractures healed, with a union period of 4.6+/-1.0 months (95% confidence interval, 4.1-5.1 months) for osteotomy cases and 4.6+/-1.1 months (95% confidence interval, 3.8-5.4 months) for nonosteotomy cases (p = 0.83). However, in the osteotomy group, two patients sustained osteonecrosis of the femoral head, and nonunion remained in 1 patient at the osteotomy site (complication rate, 18%; 3 of 17 patients). There were no complications in the nonosteotomy group (p = 0.26). The average lengthening achieved from osteotomy was 1.0 to 1.5 cm (p < 0.001). CONCLUSION: Using SCS without SVO to treat femoral neck nonunions can result in a very satisfactory outcome. It is thus preferred for indicated patients. SCS without SVO, however, cannot concomitantly correct a femoral neck shortening; furthermore, shortening may deteriorate because of a telescoping effect. For patients with evident shortening, therefore, combined SVO with SCS is more suitable.

Adolescent↗