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Biomedical subjects

S Zhong

Publications and source records attributed to S Zhong.

At least 91 records · Page 5Linked to original sources
PubMed1999

[Applied anatomy on musclebone flap of hyoideumomohyoid to renovate vocal fold].

OBJECTIVE: In order to provide anatomical basis for renovating vocal fold with muscle-bone flap of hyoideum-omohyoid. METHOD: It was measured that the anatomical structure correlative with superior belly of hyoideum-omohyoid, artery, vein and nerve of the muscle and vocal fold morphosis by 26(52 sides) cephalocevical sample dissection. RESULT: It was observed that the muscle is 74.8 mm in length, 8.4 mm in width of starting part, 9.6 mm in width of middle part, 4.4 mm in width of tendon part. Its blood supply are mainly from cricothyriod artery (51.9%) and superior laryngeal artery (25.0%) with an arterial trunk of 9.8 mm in length and 0.7 mm in diameter. The venous trunk is 17.4 mm in length and 1.1 mm in diameter. The muscle is innervated by the sub-broaches arising from hypoglossal nerve ansa, the trunk is 19.6 mm in length and 0.6 mm in diameter. CONCLUSION: It is possible that musclebone flap of hyoideumomohyoid to renovate vocal fold according to the study of the muscle morphology characteristic.

Female↗
PubMed1999

[Evaluation of intraoperative ultrasonography for hepatic neoplasm in surgery].

OBJECTIVE: The purpose of this study was to evaluate the impact of intraoperative ultrasound (IOUS) on the management of patients with neoplasms of the liver. METHODS: Forty-nine patients received operations for liver tumors were examined intraoperatively with 5.0 MHz special ultrasound transducers during surgical exploration of the abdomen. Preoperative imaging studies including percutaneous ultrasound (n = 49), magnetic resonance imaging (n = 11), and computed tomography (n = 34) were taken to compare with intraoperative ultrasonography for the evaluation. RESULTS: Sensitivity for detection of hepatic neoplasms showed in intraoperative ultrasound, percutaneous ultrasound, magnetic resonance imaging and computed tomography as 100%(23/23), 74%(17/23), 74%(14/19), and 75%(6/8) respectively. Specificity showed 100%(26/26), 100%(26/26), 93%(14/15), and 67(2/3) respectively. CONCLUSIONS: Intraoperative ultrasound was the most sensitive and specific method for detection and surgery of liver neoplasms, especially the occult neoplasms and small size lesion (< 2 cm).

Aged↗
PubMed1999

[The applied anatomy of the periosteal flap composed of submental artery and dgastric muscle].

OBJECTIVE: To provide anatomical basis for a new style operation using periosteal flap composed of submental artery, anteroventral portion of digastric muscle and submental artery for the renovation of laryngotrachea. METHODS: The anatomical structures correlative with submental artery, submental vein, anteroventral portion of digastric muscle and mandibular periosteum in 23 (46 sides) cephalocervical samples were measured. RESULTS: The periosteal flaps had shown many advantages inculding large transfer capacity, rich blood supply, flexibility. CONCLUSION: It is feasible that the periosteal flap composed of submental artery, anteroventral portion of digastric muscle and mandibular periosteum is useful laryngotracheal renovation.

Arteries↗
PubMed1999

Intraoperative ultrasound for hepatic neoplasm during surgery.

OBJECTIVE: The purpose of this study was to determine the impact of intraoperative ultrasound (IOUS) on the management of patients with neoplasms of the liver. METHODS: Forty-nine patients operated on for liver or other pathologic processes were examined intraoperatively with 5.0 MHz special ultrasound transducers during surgical exploration of the abdomen. Subjects were evaluated because of known or suspected disease of the liver. Preoperative imaging studies included percutaneous ultrasound (n = 49), magnetic resonance imaging (n = 11), and computed tomography (n = 34). Intraoperative evaluation on all patients included inspection, bimanual palpation, and ultrasonography. Comparison between preoperative imagings and IOUS were analysed. RESULTS: Sensitivity for detection of hepatic neoplasms showed in intraoperative ultrasound, percutaneous ultrasound, magnetic resonance imaging and computed tomography as 100% (23/23), 74% (17/23), 74% (14/19) and 75% (6/8). Specificity showed 100% (26/26), 100% (26/26), 93% (14/15) and 67 (2/3). In seven patients (14%), the neoplasms were not found by inspection, bimanual palpation, and identified only by IOUS. CONCLUSIONS: Intraoperative ultrasound is the most sensitive and specific method for detection and surgery of liver neoplasms, especially the occult neoplasms and small size lesion (< 2 cm).

Carcinoma, Hepatocellular↗
PubMed1998

Comparison of the strengths of lumbosacral fixation achieved with techniques using one and two triangulated sacral screws.

STUDY DESIGN: The strength of sacral screw fixation achieved with techniques using one sacral screw and two triangulated sacral screws with Chopin block was tested on 10 fresh human sacrum specimens. OBJECTIVES: To compare the stiffness and the failure strength of single sacral screw fixation and those of two divergent triangulated sacral screw fixation under different loading conditions. SUMMARY OF BACKGROUND DATA: Weak sacral screw fixation is the major cause of failure in instrumented lumbosacral fusion. Although previous studies have evaluated the strength of anteromedially and anterolaterally inserted sacral screws, the strength of two divergent triangulated sacral screws has not been evaluated biomechanically. It is assumed that increasing the number of sacral screws and using a triangulated insertion technique may increase the strength of purchase for lumbosacral fixation. METHODS: Ten fresh human sacrum specimens were used in this study. Six specimens were from donors less than 30 years of age (younger group), and the other four were from donors more than 60 years of age (aged group). The specimens were assigned randomly to either one side one S1 pedicle screw inserted anteromedially or to the other side with two screws directed anteromedially and anterolaterally. All specimens were tested with an Instron material testing machine (Instron Limited, High Wycombe, England). The average stiffness under compression, tension, and torsion were calculated from the average slopes of the load deformation curves. The failure load was applied for the final testing. RESULTS: The results showed significant differences in stiffness between fixation with one screw and fixation with two divergent triangulated screws. With one S1 pedicle screw fixation, the average stiffness was 203 N/mm for compression, 147 N/mm for tension, and 2 Nm/degree for torsion. With two-screw fixation the average stiffness increased to 255 N/mm (126%), 185 N/mm (126%) and 2.4 Nm/degree (120%), respectively. The average failure strength under tension loads was found to be 1450 N in the younger specimens and was reduced to 980 N in the aged specimens. CONCLUSION: This study showed that fixation with two divergent triangulated screws to the sacrum was significantly stronger than one-screw fixation for lumbosacral fusion. The strength of fixation seems to have a negative correlation with aging.

Adult↗
PubMed1998

Lymphohematopoietic engraftment in minimally myeloablated hosts.

The concept that myeloablation to open space was a prerequisite for marrow stem cell engraftment has been challenged by studies showing high rates of engraftment in nonmyeloablated mice (Stewart et al, Blood 81:2566, 1993; Quesenberry et al, Blood Cells 20:97, 1994; Brecher et al, Blood Cells 5:237, 1979; Saxe et al, Exp Hematol 12:277, 1984; and Wu et al, Exp Hematol 21:251, 1993). However, relatively large numbers of marrow cells were necessary to achieve high long-term donor percentages. We have demonstrated, using a BALB/c male/female marrow transplant model and detecting male DNA in host tissues by Southern blot or fluorescent in situ hybridization, that exposure to doses of irradiation that cause minimal myeloablation (50 to 100 cGy) leads to very high levels of donor chimerism, such that relatively small numbers of marrow cells (10 to 40 million) can give donor chimerism in the 40% to 100% range. Studies of radiation sensitivity of long-term engrafting cells have shown that 100 cGy, although not myelotoxic, is stem cell toxic, and indicate that the final host:donor ratios are determined by competition between host and donor stem cells. These data indicate that low levels of irradiation should be an effective approach to nontoxic marrow transplantation in gene therapy or in attempts to create allochimerism to treat such diseases as cancer, sickle cell anemia, or thalassemia.

Animals↗
PubMed1998

Paradoxical sympathetic nerve response to baroreceptor reflex activation.

Spectral analysis revealed an enhancement of cardiac-related postganglionic sympathetic nerve discharge (SND) in response to elevated blood pressure in cats. Most of the enhancement occurred at blood-pressure levels above which coherence of SND to the arterial pulse at the frequency of the heart beat became maximal. This raises the possibility that the enhancement is due to mechanisms other than improved phase locking of SND to pulse-synchronous baroreceptor afferent nerve activity.

Animals↗
PubMed1998

Paradoxical sympathetic nerve response to baroreceptor reflex activation

Spectral analysis revealed an enhancement of cardiac-related postganglionic sympathetic nerve discharge (SND) in response to elevated blood pressure in cats. Most of the enhancement occurred at blood-pressure levels above which coherence of SND to the arterial pulse at the frequency of the heart beat became maximal. This raises the possibility that the enhancement is due to mechanisms other than improved phase locking of SND to pulse-synchronous baroreceptor afferent nerve activity.

Journal Article↗
PubMed1998

Mobilization of peripheral blood progenitor cells by Betafectin PGG-Glucan alone and in combination with granulocyte colony-stimulating factor.

Betafectin PGG-Glucan, a novel beta-(1,6) branched beta-(1,3) glucan purified from the cell walls of Saccharomyces cerevisiae, has been shown to synergize with myeloid growth factors in vitro and to enhance hematopoietic recovery in myelosuppressed mice and primates. Here we report that PGG-Glucan is also capable of mobilizing peripheral blood progenitor cells (PBPC). PGG-Glucan (0.5 mg/kg to 16 mg/kg) was administered intravenously to C3H/HeN male mice and blood collected at times ranging from 30 min to seven days after injection. Based on granulocyte-macrophage colony-forming cell (GM-CFC) levels, peak mobilization occurred 30 min after a 2 mg/kg PGG-Glucan dose. At this time GM-CFC numbers in PGG-Glucan-treated mice were approximately fourfold greater than in saline-treated control mice. A second, smaller wave of GM-CFC mobilization (approximately twofold increase) also occurred on days 4 and 5 after PGG-Glucan treatment. Mobilization was not associated with the induction of alpha-chemokines, which have recently been reported to induce rapid progenitor cell mobilization. Competitive repopulation experiments performed in irradiated female C3H/HeN mice revealed that, at three months after transplantation, more male DNA was present in bone marrow, splenic, and thymic tissues from animals transplanted with cells obtained from mice 30 min after a 2 mg/kg PGG-Glucan dose than in tissues from animals transplanted with cells obtained from saline-treated mice. Additional experiments evaluated the mobilization effects of PGG-Glucan (2 mg/kg) administered to mice which had been pretreated for three consecutive days with G-CSF (125 microg/kg/day). When blood was collected 30 min after PGG-Glucan treatment, the number of GM-CFC mobilized in combination-treated mice was additive between the number mobilized in mice treated with G-CSF alone and the number mobilized in mice treated with PGG-Glucan alone. These studies demonstrate that: A) PGG-Glucan can rapidly mobilize PBPC; B) the kinetic pattern of PGG-Glucan-induced mobilization is different from that of the CSFs; C) the reconstitutional potential of PGG-Glucan mobilized cells is greater than that of steady-state PBPC, and D) PGG-Glucan can enhance G-CSF-mediated PBPC mobilization.

Adjuvants, Immunologic↗
PubMed1998

PML is essential for multiple apoptotic pathways.

The PML gene of acute promyelocytic leukaemia (APL) encodes a cell growth and tumour suppressor, however, the mechanisms by which PML suppresses tumorigenesis are poorly understood. We show here that Pml is required for Fas- and caspase-dependent DNA-damage-induced apoptosis. We also found that Pml is essential for induction of programmed cell death by Fas, tumour necrosis factor alpha (TNF), ceramide and type I and II interferons (IFNs). As a result, Pml-/- mice and cells are protected from the lethal effects of ionizing radiation and anti-Fas antibody. Pml is required for caspase 1 and caspase 3 activation upon exposure to these stimuli. The PML-RAR alpha fusion protein of APL renders haemopoietic progenitor cells resistant to Fas-, TNF- and IFN-induced apoptosis with a lack of caspase 3 activation, thus acting as a Pml dominant-negative product. These results demonstrate that Pml is a mediator of multiple apoptotic signals, and implicate inhibition of apoptosis in the pathogenesis of APL.

Animals↗
PubMed1998

Nonlinear interactions of slow and rapid rhythms in sympathetic nerve discharge.

We used bispectral analysis to characterize the nonlinear interactions of the respiratory-related (RR), cardiac-related (CR), or 10-Hz rhythms in sympathetic nerve discharge (SND) of urethan-anesthetized cats. Bispectral analysis investigates relationships among frequency triples in the same signal (inferior cardiac postganglionic SND) where the third frequency is the sum of the other two due to quadratic nonlinear coupling. Coupling of the RR and CR rhythms leading to the generation of new components (i.e., modulated frequencies) in SND occurred in 84% of the total cases, whereas the incidence was 71% for the RR and 10-Hz rhythms. The occurrence of such nonlinear interactions implies that the RR, CR, and 10-Hz rhythms are carried to common targets by the same postganglionic sympathetic neurons. Furthermore, we suggest that nonlinear interactions leading to the generation of new frequencies in SND may affect end-organ function beyond the level expected in simple cases of linear superposition of the primary rhythms. This suggestion is supported by our observation that strong coupling of the RR and CR rhythms resulted in appreciable power at the modulated frequencies.

Animals↗
PubMed1998

[A study on the relationship of primary hypertension in elderly and their quality of life in Changsha City].

To study the relationship between hypertension and their quality of life in Changsha City, in the elderly primary questionnaire concerning quality of life developed by the Chinese Geriatric Association was used to investigate 555 aged workers. A community-based control programme on hypertension and it's impact was analysed. The results of stepwise regression suggested that physical status and function of daily activities were both subjective and objective determinants of importance. Morbidity of hypertension was the highest among all chronic diseases influecing aged worker's health status. The total score of quality of life and activities in aged people with hypertension was obviously low. There were many problems in the community-based control program on hypertension in urban districts. The treatment on systolic hypertension has positive effect. Strenthening community-based control of hypertension has important impact on improving the quality of life among aged people.

Aged↗
PubMed1998

[The effect of the macrophages conditioned media(MOCM) on NGF secretion in newborn rat schwann cells in vitro].

OBJECTIVE: To study the influence of macrophages on nerve growth factor (NGF) secretion in newborn rat schwann cells. METHODS: LPS-activated and not-activated adult rat peritoneal macrophages conditioned media (MOCM) were treated on purified cultured Schwann cells for 24, 48 and 72 hours in three different concentrations the NGF contents in the cultured Schwann cells suspension media were measured by a two-site enzyme-linked immunoserbent assay. RESULTS: Both L-MOCM (LPS-activated MOCM) and N-MOCM(not-activated MOCM) obviously enhanced NGF secretion in chwann cells in each different concentration or testing time. CONCLUSION: MOCM contains some factors which can promote NGF secretion in rat schwann cells in vitro, suggesting that macrophages regulating NGF secretion by secreted certain cytokines.

Animals↗
PubMed1998

Osteogenesis of electrically stimulated bone cells mediated in part by calcium ions.

Culture selected and expanded osteoblastic cells may be able to be reintroduced into massive skeletal defects to accelerate cell mediated regeneration of skeletal tissues, especially in bone ingrowth in total joint replacement, fracture healing, and osteoporosis. In vitro osteogenic cell culture is a useful model in studying the mechanism of bone metabolism under direct current stimulation. In this study, an osteoblastlike cell line was isolated from newborn rat calvaria. The osteogenic processes of the in vitro cultured cell line were studied by cytochemical, electron microscopic, and energy dispersive x-ray analysis techniques that resembled those observed in membrane bone ossification centers in vivo. Direct current stimulation of 100 microA/cm2 accelerated greatly the proliferation and calcification of the in vitro cultured cells. Intracellular free calcium ion metabolism was measured with an Adherent Cell Analysis and Sorting Machine. Under direct current stimulation, intracellular free calcium ion concentration increased an average of 2.3 times of the original level, which may play a key role in regulating osteogenesis and bone metabolism.

Alkaline Phosphatase↗
PubMed1998

Chiaroscuro hematopoietic stem cell.

These observations suggest several immediate clinical strategies. In gene therapy, approaches could be targeted to obtain cycling of hematopoietic stem cells and gene-carrying retrovirus vector integration followed by engraftment at an appropriate time interval which favors engraftment. The same type of approach can be utilized for stem cell expansion approaches. Alternatively marrow or peripheral stem cell engraftment can be obtained with minimal to no toxicity in allochimeric strategies in such diseases as sickle cell anemia or thalassemia. A similar approach could be useful in obtaining cell engraftment with minimal toxicity in therapies employing cellular immune (T-cell and NK-cell) attack against cancer. These areas of clinical application are outline in Table 3.

Animals↗
PubMed1997

Engraftment of hematopoietic stem cells in nonmyeloablated and myeloablated hosts.

Hematopoietic stem cell engraftment has traditionally been assessed in irradiated murine hosts. More recently, we and others have shown that engraftment is virtually quantitative in host animals who have received no preconditioning myeloablation. It appears that at the stem cell level, engraftment may even be favored in the normal host. The final phenotypic readout in the engrafted animal is then determined by competition between the engrafted stem cells and the number of residual host stem cells. Further studies have indicated that with cytokine exposure in vitro, in vivo or 5-fluorouracil exposure and consequent stimulation of primitive hematopoietic stem cells to enter cell cycle, an engraftment defect relating to long-term engraftment occurs. This occurs in the face of an expansion of cycling surrogate stem cells as mirrored by the high proliferative potential colony-forming cell. These data indicate that the phenotype of the hematopoietic stem cell, as assessed in vitro, may not give insight into the phenotype of these cells in vivo.

Animals↗