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K Lu

Publications and source records attributed to K Lu.

At least 73 records · Page 4Linked to original sources

Spontaneous regression of periodontoid pannus mass in psoriatic atlantoaxial subluxation. Case report.

STUDY DESIGN: A case report of a 41-year-old man with psoriasis who had cervical myelopathy caused by atlantoaxial subluxation and periodontoid pannus mass. OBJECTIVE: To describe the possible mechanism underlying the periodontoid pannus formation and the optimal treatment for such cases. SUMMARY OF BACKGROUND DATA: Atlantoaxial subluxation causing spinal cord compression at the craniocervical junction may develop in patients with rheumatoid or psoriatic arthritis. Periodontoid pannus formation plays an important role in compromising the anteroposterior diameter of the spinal canal and in causing neurologic deficits. Transoral transpharyngeal excision of the pannus is sometimes thought necessary for anterior decompression of the spinal cord. Spontaneous resolution of the periodontoid pannus after posterior atlantoaxial fusion and fixation has been documented in rheumatoid arthritis, but not in psoriatic arthritis. METHODS: The patient underwent posterior atlantoaxial fusion and Halifax fixation. RESULTS: The patient experienced clinical improvement. Regression of the periodontoid pannus mass was observed on magnetic resonance imaging. CONCLUSIONS: Posterior fusion and instrumentation resulted in spontaneous regression of the pannus mass and symptomatic relief. This report provides evidence that atlantoaxial instability may be the sine qua non for the formation of periodontoid pannus, and that amelioration of such instability leads to spontaneous resolution of the pannus mass.

Adult↗

Cardiomegaly in the juvenile visceral steatosis (JVS) mouse is reduced with acute elevation of heart short-chain acyl-carnitine level after L-carnitine injection.

The long-term administration of L-carnitine was very effective in preventing cardiomegaly in juvenile visceral steatosis (JVS) mice, which was confirmed by heart weight as well as the lipid contents in heart tissue. After i.p. injection of L-carnitine, the concentration of free carnitine in heart remained constant, although serum free carnitine level increased up to 80-fold. On the other hand, a significant increase in short-chain acyl-carnitine level in heart was observed. These results suggest that increased levels of short-chain acyl-carnitine, not free carnitine, might be a key compound in the protective effect of L-carnitine administration in JVS mice.

Aging↗

Orientation of particles in an electrorheological fluid under an electric field.

The orientation of the particles in an electrorheological fluid under an electric field has been studied. Triglycine sulfate (TGS)-wax mixtures were applied in this study. Here the TGS particles are in the ferroelectric phase with spontaneous polarization p(s) in the <010> direction at below the Curie temperature T(C) and become paraelectric without a permanent electric moment at above T(C). By measuring x-ray-diffraction intensities of TGS/wax samples under an electric field at below and above T(C), respectively, it is found that the particles with spontaneous polarization turn their p(s) vectors to the direction of the external electric field in addition to forming chains or columns. However, the particles without permanent moment only form chains or columns, in which no preferred orientation of the particles can be observed. The preferred orientation degree is determined by comparing the diffraction intensity in these two cases.

Journal Article↗

Renal tubular acidosis, hypokalemic paralysis, rhabdomyolysis, and acute renal failure--a rare presentation of Chinese herbal nephropathy.

We encountered a 66-year-old Chinese man presented with hypokalemic paralysis, rhabdomyolysis and acute renal failure after administration of mixed Chinese herbs. Proximal renal tubular acidosis and selective glucosuria were the main tubular dysfunctions. The renal failure recovered smoothly and rapidly after resuscitation and the tubular function abnormalities regained spontaneously after medicine withdrawal. It should be recognized that renal tubular acidosis with hypokalemic paralysis, rhabdomyolysis and subsequent acute renal failure may develop after taking Chinese mixed herbal medicine.

Acidosis, Renal Tubular↗

Transpedicular instrumentation as an adjunct in the treatment of thoracolumbar and lumbar spine tuberculosis with early stage bone destruction.

OBJECT: Because modern imaging techniques now allow for early diagnosis of spinal tuberculosis, more conservative management options are possible. The authors evaluated the effectiveness of transpedicular instrumentation for treatment of thoracolumbar and lumbar spinal tuberculosis in patients with mild bone destruction and the main symptom of "instability catch" (a sudden painful "snap" that occurs when one extends from a forward bent to an upright position). METHODS: Eighteen patients (nine men and nine women, age range 49-71 years) with spinal tuberculosis were treated with transpedicular instrumentation that was supplemented with posterolateral fusion and chemotherapy. All patients were wheelchair dependent or bed-ridden due to severe instability catch, with a mean symptom duration of 2.5 months (range 1-6 months). Two contiguous vertebrae were involved in 17 patients, and a single vertebrae was involved in one. In five patients mild neurological deficits (Frankel Grade D) were present. During surgery, the screws were implanted into the two nonaffected pedicles nearest the lesion to stabilize the involved segments. No attempt at radical debridement or neural decompression was undertaken. The follow-up period ranged from 21 to 40 months. Postoperatively the instability catch was relieved within 10 days (excellent outcome) and within 1 month (good outcome) in seven and eight patients, respectively, and within 3 months (fair outcome) in two; in the remaining patient, the symptom did not resolve (poor outcome). A short duration of symptoms (generally < 3 months) and bone destruction of less than 50% in the involved vertebral bodies were observed in patients who made a good or excellent outcome. During the follow-up period, good maintenance of spinal alignment, stabilization of the involved segment, and resolution of the inflammatory process were shown; however, there was no strong evidence that fusion had occurred at the bony defect. Patients in whom a fair outcome was achieved experienced a longer duration of symptoms, and in each, one vertebral body with greater than 50% bone destruction was demonstrated. However, good maintenance of spinal alignment was also shown during the follow-up period. The patient whose outcome was poor had the longest history (6 months) of symptoms and the most extensive involvement of the spine (> 50% destruction of two adjacent lumbar vertebral bodies). Postoperatively, implant failure occurred and the patient developed a wound infection. CONCLUSIONS: Transpedicular instrumentation provides rapid relief of instability catch and prevents late angular deformity in patients with thoracolumbar and lumbar spinal tuberculosis in whom limited (< 50%) bone destruction of the involved vertebral bodies has been shown and whose main symptom is instability catch.

Aged↗

Persistent induction of apoptosis and suppression of mitosis as the basis for curative therapy with S-1, an oral 5-fluorouracil prodrug in a colorectal tumor model.

In an effort to improve the therapeutic selectivity of 5-fluorouracil (FUra) against colorectal cancer, S-1, a combination agent including a prodrug of FUra with two modulators, was recently developed by Taiho Pharmaceuticals Co. S-1 is a combination of tegafur (FT), 5-chloro-2,4-hydroxypyridine, and potassium oxonate in the molar ratio of 1.0:0.4:1.0, with the latter two components as inhibitors of dihydropyrimidine dehydrogenase and phosphoribosylpyrophosphate transferase, respectively. In this study, the therapeutic selectivity and efficacy of S-1 (oral) was compared with FT (oral) and FUra (i.v. infusion) in rats bearing advanced colorectal cancer by using clinically relevant schedules. The maximum tolerated doses (MTDs) of S-1, FT, and FUra were 31.5, 200, and 25 mg/kg/d for 7 days and 22.5, 150, and 12.5 mg/kg/d for 28 days, respectively. The therapeutic index of S-1 was 4- to 5-fold higher than that of either FT or FUra. S-1 achieved 100% complete tumor regression (CR) at its MTD in both 7-day and 28-day schedules. Furthermore, the high incidences of stomatitis, alopecia, and diarrhea observed with FUra and FT, were not observed with S-1. In an attempt to understand the basis for the observed superior therapeutic selectivity with S-1, we studied pharmacokinetic analysis of FUra, drug-induced apoptosis, suppression of mitosis, and inhibition of thymidylate synthase (TS) after S-1, FUra, or FT administration. The peak plasma FUra concentrations derived from FUra or S-1 (FT) at comparable MTDs were similar, but the plasma level of FUra was higher with S-1 than with FUra. Induction of high and sustained apoptosis was achieved with S-1. Although the initial level of apoptosis induced by FUra was comparable to S-1, it was not sustained. The sustained level of apoptosis appears to correlate with tumor growth inhibition. Mitotic figures were more greatly suppressed with S-1 treatment than with FUra. Studies on TS inhibition indicated that, although both S-1 and FUra caused a 4- to 6-fold induction of total TS protein, single oral administration of S-1 was superior to 24-h infusion of FUra in suppressing free TS. The data are consistent with the observation that the therapeutic efficacy of S-1 (100% cure) over FUra is associated with high and sustained levels of drug-induced apoptosis, greater suppression of mitosis, and inhibition of free TS in tumor tissues.

Animals↗

MTA (LY231514) in combination treatment regimens using human tumor xenografts and the EMT-6 murine mammary carcinoma.

An important component in the development of a new anticancer drug is an understanding of its potential for inclusion in combination treatment regimens. LY231514, a multitargeted antifolate (MTA), was tested in combination with cisplatin, methotrexate, 5-fluorouracil, paclitaxel, docetaxel, doxorubicin, LY329201 (a glycinamide ribonucleotide formyltransferase [GARFT] inhibitor), and fractionated radiation therapy in vivo using EMT-6 mammary carcinoma, human HCT 116 colon carcinoma, and human H460 nonsmall cell lung carcinoma grown as xenografts in nude mice. Isobologram methodology was used to determine the additivity or synergy of the combination regimens. MTA administered with cisplatin, paclitaxel, docetaxel, or fractionated radiation therapy produced additive to greater than additive tumor response by tumor cell survival assay and tumor growth delay. While an additive tumor response was observed when MTA was administered with methotrexate, synergistic tumor responses were seen when MTA was administered with the GARFT inhibitor, LY329201, or with the topoisomerase I inhibitor, irinotecan. MTA was administered in combination with full doses of each anticancer agent studied, with no evidence of increased toxicity resulting from the combination.

Animals↗

[Effects of hyaluronic acid-stimulating factor on viability and collagen synthesis of fibroblasts].

OBJECTIVE: To study the effects of hyaluronic acid-stimulating factor(HASF) on viability and collagen synthesis of fibroblasts derived from human dermis and scars. METHODS: HASF was purified from amniotic fluid and fetal serum of gestational rabbits, and its activity was determined. To observe the effects of HASF on viability and collagen synthesis of two cell lines, AgNORs staining, 3H-proline incorporation and HYP determination were carried out. RESULTS: HASF reduces AgNORs contents in skin FB and scar FBi 3H-proline incorporation and HYP contents were lower in experimental groups than those in controls in both cell lines. Two methods to detect collagen correlate well with each other. CONCLUSION: HASF inhabits viability and collagen synthesis of both cell lines, thus may interfered with the formation of scar during wound healing.

Adult↗

The relationship between interleukin-8 and airway hyperresponsiveness in guinea pigs.

OBJECTIVE: To explore the relationship between interleukin-8 (IL-8) and airway hyper-responsiveness (AHR) of asthma in guinea pigs. METHODS: IL-8 at a dose of 0.5 microgram/kg or 5.0 micrograms/kg was administered intranasally to guinea pigs twice a week for 3 weeks. 24 hours after the last administration, airway responsiveness was measured as an overall index of airway response to the increasing concentrations of histamine inhaled (25, 50, 100 and 200 micrograms/ml), and the numbers of different inflammatory cells in bronchoalveolar lavage fluid (BALF) were counted. RESULTS: The IL-8 treatment significantly enhanced airway responsiveness to histamine in a dose-dependent manner (P < 0.05 or P < 0.01) and induced a significant influx of neutrophils in BALF (P < 0.01), and a great number of neutrophils were seen within the airway wall, but not within the control animals treated with phosphate buffered saline (PBS). CONCLUSION: The IL-8 could produce neutrophil inflammation of the airways and induce AHR, which suggested that IL-8 may play an important role in asthma, especially in the development of AHR.

Animals↗

Characteristics of cardiac hypertrophy in the juvenile visceral steatosis mouse with systemic carnitine deficiency.

The juvenile visceral steatosis (JVS) mouse exhibits hereditary systemic carnitine deficiency and develops cardiac hypertrophy. The aim of this study was to clarify the characteristics of cardiac hypertrophy in the JVS mouse. Total carnitine content in IVS mouse heart was about 10% of that of control mouse heart at 4 and 8 weeks of age. The heart weight/body weight ratio was bigger in JVS mice than that in control mice at 2 weeks of age, and this difference in ratio increased with age. The wall areas of both ventricles and septum in JVS mice were larger than those of the control mice at 2 and 8 weeks. The myocyte diameter in both ventricular walls and septum in JVS mice was longer than that of the control mice. On electron microscopy, the percent of mitochondria in the myocyte was 66% in JVS mice, and 37% in control mice. The percent of lipid fraction in JVS mice was six-fold higher than that in control mice. Total content of adenine nucleotides in JVS mouse heart was about 60% of that in control mouse heart. Adenylate energy charge in JVS mouse heart was 63 and 45% of that in the control mouse heart at 4 and 8 weeks, respectively. Overall, the cardiac enlargement observed in this animal model could be accounted for by a proportional increase in the myocyte diameter in the ventricles and septum, accompanied by an increase in mitochondria. Furthermore, this cellular growth is associated with decreases in the levels of ATP and ADP, and adenylate energy charge.

Adenosine Diphosphate↗

Closed reduction of bilateral locked facets of the cervical spine under general anaesthesia.

BACKGROUND: Bilateral facet interlocking of the cervical spine is a relatively uncommon type of cervical spinal injury. It is frequently associated with devastating neurological symptoms and signs. Early reduction of the locked facets is thought to be critical in preventing progressive secondary spinal cord injury. Whereas skull tong traction remains our primary option for closed reduction of bilateral locked facets of the cervical spine, it is not always successful, even with heavy traction weights. Other more aggressive measures may occasionally be required. The authors report their experience in reducing bilateral locked facets of the cervical spine by manual closed reduction. METHODS: This small series consists of six cases of cervical spinal injury with bilateral locked facets in which manual closed reduction under general anaethesia and muscle relaxation was used. Three of them presented with complete quadriplegia (Frankel class A). One case presented with incomplete but severe neurological deficits (Frankel class B). After unsuccessful closed reduction with skull traction, these patients were treated by manual closed reduction under general anaesthesia and muscle relaxation, followed by anterior discectomy, interbody fusion and stabilization. RESULTS: All cases made neurological improvement after the procedures. Even in cases with initial severe neurological deficits, the recovery was remarkable. The recovery was dramatic in two cases. Case 1 improved from Frankel class B to E; and Case 5 from Frankel class A to D. No case deteriorated neurologically after the procedures. Pneumonia occurred in Case 3; and stress ulcer accompanied by haemorrhage was noted in Case 4. None of these complications was directly related to the procedures. CONCLUSION: The potential for improvement of neurological function following early and successful reduction and fixation of the dislocated spine is emphasized. With meticulous techniques, manual closed reduction may be an effective alternative to skull tong traction when the latter fails.

Adult↗

Comparison between short or long exposure to 5-fluorouracil in human gastric and colon cancer cell lines: biochemical mechanism of resistance.

Recent preclinical and clinical data indicate that the main mechanisms of 5-fluorouracil (5-FU) cytotoxicity depend on the mode of administration. To gather further insight into the major causes of acquired 5-FU resistance, drug-sensitive human gastric (M2), colon (HT29) and breast (MCF7) cancer cell lines were repeatedly exposed to a fixed concentration of 5-FU given either for 1 or 24 h. Although equieffective doses (IC50) of 5-FU were used, resistance to a 1 h exposure of 5-FU developed faster in all models than to a 24 h exposure. Cell lines with acquired resistance to a 1 h application of 5-FU were only partly cross-resistant to a 24 h exposure, whereas lines with resistance to protracted application of 5-FU displayed significant cross-resistance to the 1 h schedule. Resistance to methotrexate was only seen in cell lines with acquired resistance to 24 h of 5-FU. All 5-FU-resistant cell lines showed reduced incorporation of 5-FU into cellular RNA. Furthermore, elevations of thymidylate synthase were seen in all cell lines with resistance to 24 h of 5-FU but also in one cell line with resistance to a bolus schedule. No alterations in folylpolyglutamate synthase developed in the resistant cell lines. These data support the concept that the main mechanisms of 5-FU cytotoxicity depend on the mode of application. Incorporation of fluorouridine triphosphate into RNA appears to be the most important mechanism of action for 5-FU bolus schedules, whereas inhibition of thymidylate synthase becomes more important as the infusion time is prolonged. These data could have implications on the interaction of 5-FU given at different schedules with various other cytostatic agents.

Adenocarcinoma↗

Successful removal of a hemangioblastoma from the medulla oblongata: case report.

Hemangioblastomas are histologically benign tumors that occur exclusively within the neuraxis, most commonly in the posterior fossa. They are typically cystic tumors located in the cerebellum. Excision of the vascular mural nodules leads to cure. Brain stem lesions are rarely reported. Surgical extirpation of a solid brain stem hemangioblastoma is relatively risky and requires precise microsurgical techniques. We present a woman with a hemangioblastoma embedded in the medulla oblongata. This 33-year-old woman presented with occipital headaches and sensory ataxia. Complete and detailed preoperative imaging studies were followed by successful microsurgical excision of the lesion. The patient recovered completely within 2 weeks after the operation except for mild paresthesia of the legs. Preoperative magnetic resonance imaging and cerebral angiography provided important information regarding the nature, location, and blood supply of this lesion, which facilitated its total removal. The importance of intraoperative identification and control of the feeding artery of the tumor is emphasized.

Adult↗

[Pathogenetic study of femoral head necrosis caused by cortical steroid].

OBJECTIVE: To study cortical steroid caused femoral head necrosis. METHODS: We designed an experimental animal model of femoral head necrosis through cortical steroid administration. Lipid analyses of blood samples were made and examined specimens from livers and femoral heads were studied with HE, TEM methods. RESULTS: Cortical steroid resulted in dearrangement of fat metabolism, lipid change of liver and hyperlipemia. CONCLUSION: The pathogenesis of femoral head necrosis is due to fatty degeneration of osteocytes.

Animals↗

[Significance of resistance index and pulsatility index in differential diagnosis of breast neoplasm].

OBJECTIVE: To investigate the significance of the resistance index (RI) and pulsatility index (PI) in differential diagnosis between the benign and malignant breast neoplasms. METHODS: Forty-seven cases of malignant breast tumors, sixty-nine cases of fibroadenomas, seven cases of inflammatory masses and twenty-two cases of mammiplasia were demonstrated on color Doppler flow imaging (CDFI). The measurements of RI and PI of the four groups were recorded respectively and the comparison between benign and malignant neoplasms was made by applying Doppler quantitative analysis. RESULTS: The color flow was detected in 59.4% of benign breast neoplasms and in 89% of malignant ones respectively (chi 2-test, P < 0.001). There were significant difference between benign and malignant neoplasms on the RI and PI. The malignant neoplasms were characteristic of higher RI (> or = 0.70) and PI (> or = 1.30), which were of satisfactory value for differential diagnosis, amounting to 95.5% of accuracy. CONCLUSIONS: Combination of both color Doppler analysis and 2D-US might remarkably increase the sensitivity and specificity of differential diagnosis of breast neoplasms. Our results confirmed the significance of color Doppler flow imaging and Doppler quantitative analysis on the differential diagnosis of breast neoplasms.

Adult↗

[Histological and electron microscopic study of rotator cuff tear].

OBJECTIVE: To understand the changes of rotator cuff during tear and observe the pathologic and ultramicroscopic structure of rotator cuff. METHOD: Histological and ultra thin slides of samples of 36 cases of rotator cuff were made. RESULT: The degeneration of rotator cuff happened in synovium side, and then extended to the middle and deep sides of tendon. The deep side of cuff tendon could degenerate without synovium. The repair of tendon could be achieved with two types of healing. CONCLUSION: It would be difficult to achieve full repair when complete tear and deep side tear occurred to the rotator cuff.

Adult↗

[Synthesis of spin labeled analogue of podophyllotoxin glycoside].

A novel spin labeled analogue of podophyllotoxin glycoside 9 was synthesized by condensing 4'-demthyl-epipodophyllotoxin-beta-D-glucopyranose and 4-formyl-2, 2, 6, 6-tetrahydropuridine in presence of p-TsOH and triethyl orthoformate. It was shown to exhibit activity compatible to VP-16-213 in inhibiting L1210 cells.

Animals↗