Biomedical subjects

Q Zhang

Publications and source records attributed to Q Zhang.

At least 559 records · Page 31Linked to original sources

PubMed1998

[Surgical treatment of extracranial carotid artery aneurysm].

OBJECTIVE: To study the experience in the treatment of extracranial carotid aneurysm. METHODS: 67 cases of extracranial carotid artery aneurysm(ECAA) were treated surgically from January 1986 to June 1997. RESULTS: There were a mortality rate of 1.5% and a hemiparalysis rate of 4.5%. CONCLUSION: Clinical examinations are important for diagnosis of ECAA. Angiography plays a significant role in understanding the morphology, function, pathophysiology of ECAA. To decrease postoperative cerebral ischemia, collateral circulation of cerebral vessels should be evaluated and matas test done. Correct operative method is a key factor for successfull treatment.

Adult↗

PubMed1998

[Diagnosis and surgical treatment of intramedullary epidermoid cyst of the spinal cord].

OBJECTIVE: To discuss clinical diagnosis and surgical treatment of intra-medullary epidermoid cyst. METHODS: Ten intramedullary epidermoid cysts were confirmed by operatively and pathologically from 1978 to 1995. RESULTS: The tumors were located in the spinal cord. Clinical presentation of this tumor was not specific. On CT scans, eight tumors were characterized by a homogenous low-density lesion and well-defined limits. They usually did not enhance with contrast medium. On MR imaging, four tumors were characterized by an important variability of signal intensity, well-defined limits. All patients underwent resections of epidermoid cyst, 1 total resection, and 9 subtotal resections. Eight cases were followed up from half a year to seven years. No case recurred. CONCLUSION: Total resection of epidermoid cyst is the best choice.

Adolescent↗

PubMed1998

[Ultrasonic angiography in therapeutic decision-making in peripheral occlusive vascular diseases].

OBJECTIVE: To study quickscan (QS) in different therapeutic decision-making in 55 patients with peripheral occlusive vascular diseases. METHODS: Based on QS results, 30 patients were treated conservatively. The disease progress and therapeutic effects were assessed by QS in every three months. Percutaneous transluminal angioplasty was performed successfully in 5 patients without prior diagnostic angiography. 20 patients were scheduled for surgery. Operation of eleven patients was guided by information obtained from QS findings only, which was confirmed during operation. Angiography was necessary in 9 patients except one to formulate a therapeutic strategy. RESULTS: The accuracy of QS was 92%(23/25). CONCLUSION: QS is of value in deciding the access route of angiography and PTA, and can replace preoperative angiography, Quickscan is time-saving, inexpensive, objective and accurate. It can be used in therapeutic decision making in peripheral occlusive vascular diseases and bypass grafting.

Adult↗

PubMed1998

[Histopathology observations of the facial nerve on dehiscence of the facial nerve canal].

OBJECTIVE: To explore the possible histopathologic changes induced by the seriously defective epinurium on congenital dehiscent facial nerve canal. METHODS: The facial nerves at the dehiscent facial nerve canal of 885 human temporal bones from otopathology laboratory of the University of Minnesota, USA were observed histopathologically under light microscope. RESULTS: It showed that the seriously defective epineurium at the dehiscence was found in 48 ears. Of the 48 ears, the facial nerves in forty ears had herniated out from the dehiscence area, in thirteen ears on the outgrowing facial nerve had at the dehiscence areas and facial nerves in three ears with otitis media was obviously infiltrated with inflammatory cells. No similar pathologic change was found in all the 837 ears with the dehiscence covered by epineurium. CONCLUSION: The seriously defective epineurium at the dehiscencesite is a histological cause for the herniation of facial nerve and formation of outgrowing Schwannomas and inflammatory infiltration of facial nerve.

Facial Nerve↗

PubMed1998

[Measurement of blood flow in nasal mucosa].

OBJECTIVE: To determine the amount of blood flow in the human nasal mucosa and its change in patients with nasal polyps and allergic rhinitis. METHODS: Using the Ameflow-H2, the amount of blood flow in nasal mucosa was examined in 98 normal adults, 18 cases of nasal polyps and 14 cases of allergic rhinitis before and after application of the vaso constrictor. RESULT: Before the application of the vaso constrictor, blood flow of nasal mucosa of patients with nasal polyps and allergic rhinitis was lower than that of healthy people (P < 0.01). After using the vaso constrictor, the amount of blood flow was decreased in all cases with a significant decrease in patients with nasal polyps. CONCLUSION: Ameflow-H2 may be the best tool to measure nasal blood flow than other devices. The method is technically simple, less traumatic, and repeatable.

Adolescent↗

PubMed1998

EMG study in the diagnosis and differential diagnosis of lipid storage myopathy.

Clinical, electromyographic and pathological features were studied in 18 patients with lipid storage myopathy (group I) and 18 patients with polymyositis and dermatomyositis (group II). The results showed a remarkable lower spontaneous activity(SA) incidence (14%) in group I than that (55%) in group II; 46% and 34% short-duration motor unit potentials(MUAPs) with polyphasic potentials and 74% and 71% short-duration MUAPs without polyphasic potentials respectively; the percentages of increased polyphasic MUAPs were same in the two groups. The reduced or pathologic interference patterns accounted for 61% in the group I and 50% in group II. Increased CPK, LDH and HBD were also found in both of them. It is suggested that the lipid storage myopathy may be diagnosed when patients have muscle weakness and myalgia with short-duration and low-amplitude and polyphasic MUAPs without or with occasional spontaneous activities, and increased CPK, LDH and HBD.

Adolescent↗

PubMed1998

[Investigations on the incidence of dental wedge-shaped defects and abrasion in 501 elderly population and their correlation].

OBJECTIVE: To investigate the incidence of the wedge-shaped defects and abrasion their correlation in elderly. METHODS: 501 elderly were examined. RESULTS: The prevalence of wedge-shaped defects was 89.62% and the abrasion was 100.00%. Both the occurrence rate and abrasive degree were all significantly related with the age and the location of tooth. Patients with severe abrasion had severe wadge-shaped defects. CONCLUSION: The wedge-shaped defects and abrasion are common dental diseases in elderly. There would be some common factors in causing both lesions, but the factors that promote the abrasive degree are different.

Aged↗

PubMed1998

[Investigation on the positions and relevant factors of wedge-shaped defects in the elderly].

OBJECTIVE: To investigate the position and relevant factors of wedge-shaped defects in elderly. METHODS: 462 elderly were examined. RESULTS: The occurrence rate of wedge-shaped defects was 99.1%, all had at least labial or buccal defects, with premolars the most frequent. However, 15.2% of them had lingual defects, most frequently in molars. No significant association were found between wedge-shaped defect position and tooth brushing or erosion factors in the group. In tooth with defect, the occlusal surface wear was more severe, the denture abutment teeth were more in number, and the functional mobility was increased; in teeth with lingual defect, these phenomena were more obvious. CONCLUSION: The wedgeshaped defects, besides tooth brushing and erosion factors, occlusal force and its accumulation plays a role as well, lingual lesions are more related to traumatic occlusal force.

Aged↗

PubMed1998

[Distribution of B-lymphocyte subgroup CD20 and its clinical significance in patients with myasthenia gravis].

OBJECTIVE: To assess the distribution and clinical significance of B-lymphocyte subgroup CD20 in patients with myasthenia gravis. METHOD: B-lymphocyte subset CD20 was studied in patients with thymomas associated with or without myasthenia gravis using immunohistochemistry technique. RESULT: The moderate and obvious aggregation of CD20 positive cells was found in patients with myasthenia gravis, there was a significant difference when compared with those patients without myasthenia gravis (chi(2) = 26.032, P < 0.01). There was negative correlation between the distribution of CD20 positive cells and the staging of thymomas (gamma = 0.07), and no correlation between the distribution and clinical type of myasthenia gravis (gamma < 0.4). CONCLUSION: The results of this study indicated that pathological changes of thymus are more important than those of thymomas itself in the pathogenesis of myasthenia gravis. The degree of B-lymphocyte subgroup aggregation can not truly reflect clinical status because of the heterogeneity of antibody against acetylcholine receptor.

Adult↗

PubMed1998

[The detection of breast carcinoma micrometastases in axillary lymph nodes by reverse transcriptase-polymerase chain reaction].

OBJECTIVE: To detect tumor micrometastases in axillary lymph nodes of breast carcinoma so as to obtain more reliable information about nodes status and its clinical significance. METHOD: The expression of CK19 mRNA was measured in 61 axillary lymph nodes (LNs) of 15 breast carcinomas by using reverse transcriptase-polymerase chain reaction (RT-PCR). RESULT: CK19 mRNA expression was detected in all 15 breast carcinomas, but not in 5 control LNs. Of 61 axillary LNs analysed by HE staining and CK19 RT-PCR, 7 LNs were found to have metastases by histological staining and CK19 RT-PCR. Of the remaining 54 axillary nodes, 12 were found to have metastases by using CK19 RT-PCR method. CONCLUSION: The CK19 RT-PCR method is more sensitive than histological study for the detection of micrometastases in LNs (P < 0.01). This new method is of value in differentiating breast cancer patients at high risk for relapse from those with negative lymph node.

Axilla↗

PubMed1998

[Management of true extremity aneurysms: experience in 23 patients].

OBJECTIVE: To explore the etiologic feature and specificity of diagnosis and treatment in true aneurysms of the extremities. METHOD: 23 patients with true aneurysms of the extremities from January 1984 to September 1997 were retrospectively reviewed. RESULT: Of 30 true aneurysms of the extremities, multiple aneurysms were found in 7 patients (30.4%). The multiple aneurysms were diagnosed in the same time or in different time. 21 patients were treated by exclusion of aneurysm and replacement with autogenous saphenous vein or graft. CONCLUSION: Early diagnosis and treatment are recommended to prevent complications which can cause limb loss, and multiple aneurysms must be taken into account. Importance of arteriography should be stressed in the diagnosis of multiple aneurysms. Exclusion of aneurysm and autogenous saphenous vein reconstruction is the first choice of treatment, circulation of the operated extremities should be noticed and close follow-up is imperative to pay attention to the development of new aneurysms.

Adolescent↗

PubMed1998

[Histopathologic study on intratemporal minimal facial nerve neurilemmomas].

OBJECTIVE: To explore the original location and pathologic behavior of facial nerve neurilemmomas. METHODS: Human temporal bone slides from 815(1,526 ears) were histopathologically observed under light microscope. RESULTS: Seventeen(1.84%) undiagnosed intratemporal facial nerve neurilemmoma with morphologic indications of Antoni type A were found. According to pathologic features, the intratemporal facial nerve neurilemmomas were classified as ingrowing facial nerve neurilemmomas (4 ears) which originated from the center of facial nerve, and outgrowing facial nerve neurilemmomas (13 ears) which originated from the perineurium at dehiscence of the facial nerve canal. Of the 17 tumors, two originated from the labyrinthine segment, twelve from the tympanic segment, one from second turn and two from vertical segment. CONCLUSION: It is of important pathologic and clinical significance to classify the intratemporal facial nerve neurilemmomas into outgrowing and ingrowing types.

Adult↗

PubMed1998

[In vitro release kinetics and hypoglycemic effect on diabetic rats after oral administration of insulin loaded nanoparticles].

The insulin-loaded polyalkylcyanoacrylate nanoparticles (INS-NP) were made with Dextran 70 as the stabilizer. The mean diameter of INS-NP was 252.4 nm with a poly dispersity of 0.005. The associating ratio of insulin to the nanoparticles reached 70.1% +/- 2.3%, while the loading capacity was 0.14 u.mg-1. Studies on in vitro release kinetics showed that release profiles can be well modelled using a biexponential function. The burst effect was obvious, and a faster release was observed in acidic media. After various doses of INS-NP were intragastrically given to diabetic rats, significant decrease of glucose level was achieved in the 10 and 20 u.kg-1 groups, with no significant difference between these two doses. The relative bioavailability after p.o. administration of INS-NP 10 u.kg-1 over s.c. administration of insulin solution 1 u.kg-1 was 7.58% calculated by the area over the curve of glucose level (%) versus time profiles. The correlation was obvious between the % of insulin released at pH 7.0 and the % of glucose decreased within the first 7 hours. Hence, an oral insulin preparation with rather high bioavailability was provided in this study, and its shorter effective time will make it more convenient for the control of the glucose level in clinics.

Animals↗

PubMed1998

[The structures elucidation of isodopharicin D and F].

Two new compounds were isolated from Isodon pharicus (Prain) Murata. Their structures were determined to be 3 alpha, 11 beta, 13 alpha-trihydroxy-entkaur-16-en-15-one (1), named isodopharicin D, and 11 beta, 13 alpha, 15 alpha-trihydroxy-entkaur-16-en-3 alpha-beta-D-glucoside (2), named isodopharicin F by chemical and spectral evidence.

Diterpenes↗

PubMed1998

[Chemical stability of salmon calcitonin (sCT) analogues in aqueous solution].

Calcitonin is a peptide hormone with 32 amino acids. Natural calcitonins are presumably quite unstable in solution and numerous analogues of calcitonin had been synthesized to improve the stability. In the present paper, we report the investigation of the chemical stability of salmon calcitonin (sCT) analogues [Val1, Ala7]sCT, [Val1, Ala7, Ala30]sCT and [D-Ala30]sCT in aqueous solutions by reversed phase high-performance liquid chromatography (RP-HPLC) and fast atom bombardment mass spectrometry (FAB-MS) methods. The degradation patterns of the sCT analogues showed a marked dependence on pH and temperature. Most of the degradation products in pH 9.0 solution of sCT and its analogues were identified by FAB-MS analysis. Results showed that the sCT analogues are more stable at pH 3.3 and pH 3.7 than at pH 6.0 and pH 9.0. Analogues without disulfide bridge [Val1, Ala7]sCT and [Val1, Ala7, Ala30]sCT showed higher chemical stability than sCT while [D-Ala30]sCT showed lower chemical stability than the native sCT.

Calcitonin↗

PubMed1998

[Multiple dose pharmacokinetic and bioavailability studies of oral sustained release and conventional formulations of isosorbide-5-mononitrate in healthy volunteers].

The pharmacokinetics of a new sustained release tablets (40 mg, qd) of isosorbide-5-mononitrate (IS-5-MN) was investigated together with a conventional preparation (20 mg, bid) after multiple oral administration in ten healthy human subjects using an open, randomized two-way crossover experimental design. Based on three statistical analyses of the area under the plasma concentration-time curve (AUC), the two tablet formulations are judged to be bioequivalent (P > 0.1), with a relative bioavailability of 108.95% for the IS-5-MN sustained release formulation. Pharmacokinetic data showed that the sustained release formulation reached mean peak plasma levels significantly later and lower minimum plasma concentration (Cmin), compared with the conventional preparation. But no statistically significant difference was found for other pharmacokinetic parameters including peak plasma levels (Cmax), AUC, elimination constant (Ke), elimination half-life (T1/2) and fluctuation index (FI) between the two preparations (P > 0.05).

Adult↗

PubMed1998

[Quantitative study of catecholamines in normal human dental pulp].

The purpose of this report was to study quantitatively the levels of catecholamines in human dental pulp by high-performance liquid chromatography (HPLC). 10 healthy teeth were selected from the extractions due to orthodontic reasons. The pulp of the teeth were obtained immediately after the extraction and samples were analyzed by means of HPLC for levels of dopamine, epinephrine and norepinephrine. The result showed that the concentration of norepinephrine in human dental pulp was 23.47 +/- 0.52 micrograms/g pulp tissue and dopamine was 19.17 +/- 1.03 micrograms/g pulp tissue.

Catecholamines↗

PubMed1998

[A micro transducer for dynamic multi-location pH monitoring in upper digestive tract].

A new transducer catheter used for dynamic multi-location pH monitoring in upper digestive tract has been developed. On the catheter several antimony electrodes and an Ag-Agcl electrode are integreted. An animal experiment compared the results of gastric aspiration and dynamic recording and demonstrated the reliability of this transducer. Clinical application has shown that this technology contributes greatly to the research on digestive physiology and to the diagnosis of functional diseases such as non-cardiac chest pain.

Animals↗