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Biomedical subjects

W He

Publications and source records attributed to W He.

208 records · Page 12Linked to original sources

Micromanipulation of mitotic chromosomes in PTK2 cells using laser-induced optical forces ("optical tweezers").

To study the potential use of optical forces to manipulate chromosome movement, we have used a Nd:YAG laser at a wavelength of 1.06 microns focused into a phase contrast microscope. Metaphase and anaphase chromosomes were exposed while being monitored by video microscopy. The results indicated that when optical forces were applied to late-moving metaphase chromosomes on the side closest to the nearest spindle pole, the trapped chromosomes initiated movement to the metaphase plate. The chromosome velocities were two to eight times the normal rate depending on the chromosome size, geometry, and trapping site. At the initiation of anaphase, a pair of chromatids could be held by the optical trap and kept motionless throughout anaphase while the other pairs of chromatids separated and moved to opposite spindle poles. As a result, the trapped chromosome either was incorporated into one of the daughter cells or was lost in the cleavage furrow, or the two chromatids eventually separated and moved to their respective daughter cells. If the trap was removed at the beginning of anaphase B, the chromosome moved back to the poles. Our experiments demonstrate that the laser-induced optical force trap is a potential new technique to study noninvasively the mitotic spindle of living cells.

Analysis of Variance↗

Microsurgically generated discontinuities provoke heritable changes in cellular handedness of a ciliate, Stylonychia mytilus.

Stylonychia mytilus is a dorsoventrally flattened ciliate with compound ciliary structures arranged in a specific manner on the cell surface. In mirror-image (MI) doublets of this ciliate, two nearly complete sets of ciliary structures are arrayed side-by-side, one in a normal or 'right-handed' (RH) arrangement, the other in a reversed or 'left-handed' (LH) arrangement. MI-doublets exist in two forms, one with the RH component on the right, the LH component on the left, and feeding structures near the center ('buccal-adjoining MI-doublet'); the other with the RH component on the left, the LH component on the right, and feeding structures on the lateral edges ('buccal-opposing MI-doublet'). We describe an operation that can generate either type of MI-doublet. This operation interchanges large anterior and posterior regions of the cell, transposing the original posterior region anteriorly (P----A) and the original anterior region posteriorly (A----P), while retaining the original anteroposterior polarity of each region. Two sets of new ciliary structures then are formed in mirror-image arrangement, with the set in the P----A region oriented normally and the set in the A----P region undergoing a reversal of polarity along its anteroposterior axis. This sometimes creates end-to-end MI forms, but more commonly produces side-by-side MI-doublets through a folding together of the P----A and A----P regions. This folding occurs because one lateral edge of the cell had been removed during the operation; if the left edge was removed, the complex folds to the left and forms a buccal-adjoining MI-doublet, whereas if the right edge was removed, the complex folds to the right and forms a buccal-opposing MI-doublet. Both types can reorganize and later divide true-to-type, although the 'buccal-opposing' type is by far the more stable of the two. The generation of mirror-image forms is dependent on the prior abnormal juxtaposition of regions from opposite ends of the cell, and involves a coordinated respecification of large-scale organization. We interpret this response to be a consequence of intercalation of missing intervening positional values in the zone of posterior-anterior abutment.

Animals↗

[Study on targeting drug delivery system--the animal behavior in vivo after hepatic arterial embolization of methotrexate microsphere].

The cross-linked MTX-gelatin microsphere was chosen as an experimental model. Pharmacokinetics and biodegradable period of the microsphere were studied after hepatic arterial embolization in vivo in dogs. After hepatic arterial infusion, the concentration of MTX-ms in peripheral vein blood increased rapidly and declined slowly. In contrast, the peak time of the drug concentration of infused MTX solution appeared at once and decreased rapidly. The half-life of MTX-ms in vivo was 2.14 times as much as that of MTX solution. During the assay period of sixteen hours the drug concentration of MTX-ms in hepatic vein blood was constantly higher than that of MTX solution. The follow-up angiography revealed that microsphere is a kind of peripheral embolic agent and its degradable time in vivo is about one month. Both sustained release and embolization effectiveness of microsphere will be significant in treatment of hepatic cancer.

Animals↗

Identification of a novel tumor necrosis factor alpha/cachectin from the livers of burned and infected rats.

Tumor necrosis factor alpha (TNF-alpha)/cachectin is a monocyte/macrophage-derived cytokine implicated as a proximal mediator of many of the catastrophic host responses to infection or endotoxin. However, circulating levels of TNF-alpha/cachectin have only been episodically detected in hospitalized patients with life-threatening bacterial infections. In the present report, increased quantities of immune-reactive TNF-alpha/cachectin were recovered from the livers of rats 3 days following a lethal burn and infection. Two species of TNF-alpha/cachectin were detected, one of approximately 29 kd and the other 17 kd, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In murine peritoneal macrophages and rat Kupffer cells stimulated in vitro with endotoxin, a 29-kd cell-associated and 17-kd secreted form were also detected. We conclude that the increased appearance in vivo of a 29-kd form of TNF-alpha/cachectin from the livers of lethally burned and infected rats represents a novel cell-associated form of the protein.

Animals↗

Reconstruction of the external genitals and repair of skin defects of the perineal region using three types of lateral groin flap.

Three types of lateral groin flap have been applied to reconstruct the external genitals and to repair skin defects in the perineal region. A single lateral groin flap was used to construct a vagina for 2 patients who had congenital absence of vagina. A composite flap containing iliac crest bone was applied to reconstruct the penis in 11 patients: 8 suffered traumatic amputation and 3 had congenital micropenis. A coaxial pedicle flap of the lateral groin and abdominal area was used to repair skin defects of the penis and scrotum after resection of the elephantiasis caused by recurrent erysipelas in 2 patients, and to relieve postburn scar contracture in the perineal region in another. Using this operative technique, 14 flaps survived completely with satisfactory results; 70% of one composite flap was lost as a result of hematoma. In the single-flap group, the distal portion (3 x 5 cm) of one flap necrosed and was resected and resurfaced with a free skin graft; the final result was good.

Adolescent↗

Total parenteral nutrition and bowel rest modify the metabolic response to endotoxin in humans.

Intestinal mucosal atrophy, as induced by total parenteral nutrition (TPN) and/or prolonged bowel rest, is hypothesized to enhance bowel endotoxin (LPS) translocation and may alter host responses to infection. To examine the effect of TPN-induced bowel atrophy on the response to LPS, 12 healthy volunteers were randomized to receive either enteral feedings (ENT, n = 6) or seven days of TPN without oral intake (TPN, n = 6). Enteral or TPN feedings were terminated 12 hours before the study period when a constant dextrose infusion (50 mg/kg/hour) was initiated and continued throughout the subsequent study period. After placement of arterial, hepatic vein, and femoral vein catheters, metabolic parameters were determined before and for six hours after an intravenous E. coli LPS challenge (20 U/kg). Subsequent peak levels of arterial glucagon (ENT, 189 +/- 39 pg/mL; TPN, 428 +/- 48; p less than 0.01), arterial epinephrine (ENT, 236 +/- 52 pg/mL; TPN, 379 +/- 49; p less than 0.05) and hepatic venous cachectin/tumor necrosis factor (cachectin/TNF) (ENT, 250 +/- 56 pg/mL; TPN, 479 +/- 136; p less than 0.05) were significantly higher in the TPN group than in the ENT group. The extremity efflux of lactate (ENT, -16 +/- 4 micrograms/min-100cc tissue; TPN, -52 +/- 13; t = 2 hours; p less than 0.05) and of amino acids (ENT, -334 +/- 77 nmol/min-100cc tissue; TPN, -884 +/- 58; t = 4 hours; p less than 0.05) were higher in the TPN subjects after the endotoxin challenge. Circulating C-reactive Protein (CRP) levels measured 24 hours postendotoxin were also significantly higher in the TPN subjects (ENT, 1.7 +/- 0.2 mg/dL; TPN, 3.2 +/- 0.3; p less than 0.01). Hence the counter-regulatory hormone and splanchnic cytokine responses to LPS were enhanced after TPN and bowel rest. This is associated with a magnified acute-phase response, peripheral amino acid mobilization, and peripheral lactate production. Thus antecedent TPN may influence the metabolic alterations seen in infection and sepsis via both an exaggerated counter-regulatory hormone response as well as an enhanced systemic and splanchnic production of cytokines.

Adult↗

A study of the immunofunction in patients of coronary heart disease with the fundamental deficiency and outward excess syndrome.

The fundamental deficiency and outward excess syndrome of coronary heart disease can be classified into Qi Yang deficiency with blood stasis (QYD) and Yin deficiency with blood stasis (YD). The patients showed disturbances in immunofunction manifested as marked increase of serum IgG, CIC, IC-IgG and IC-C3 levels and the percentage of B cells in the peripheral blood, while the percentages of OKT3+, OKT4+ and OKT8+ cells markedly decreased, especially the percentage of OKT8+ cells, resulting in an increase of the ratio of T4/8 and imbalance between TS and TH. The authors deem that the fundamental deficiency of coronary heart disease is related to the low cellular immunity, especially the imbalance between TS and TH cells, while outward excess of coronary heart disease is related to hyperactivity of humoral immunity.

Angina Pectoris↗

[Effects of kuo guan powder on immunologic functions in patients with ben-xu biao-shi syndrome in ischemic heart disease].

Ischemic heart disease (IHD) is correlated with the Immunodisturbances. In this study, the immunological effects of Kuo Guan No 1, a powder for aiding Qi and activating the blood, in 17 cases of Qi Yang Xu Xue Yu (QYXXY, ) syndrome, Kuo Guan No 2, powder for nourishing the Yin and activating the blood, in 14 cases of Yin-Xu Xue-Yu (YXXY, ) syndrome had been observed in one month treatment. After treatment with both powder of Kuo Guan No 1 and Kuo Guan No 2, the increased levels of IgG, CIC, IC-IgG and IC-C3 in serum and the numbers of B cells in peripheral blood lymphocyte (PBL) of the patients with Ben-Xu Biao-Shi (BXBS, ) syndrome of IHD angina were markedly decreased and showed no significant difference while compared with the normal controls (P greater than 0.05); the numbers of OKT+3, OKT+4 and OKT+8 cells in PBL, which were lower before treatment in both groups, were obviously increased and showed no marked difference with the controls (P greater than 0.05); the higher ratio of T4/T8 was lowered in group of YXXY syndrome, and showed no difference while compared with the controls (P greater than 0.05), but the ratio in QYXXY syndrome group was lowered than that in the controls (P less than 0.05). After the treatment with Kuo Guan No 1, the increased level of C3 in serum in QYXXY group was lowered down to that of the controls (P greater than 0.05). The results indicated that it is reasonable to consider that "Kuo Guan" powder is an immunoregulative preparation for patients with BXBS syndrome of IHD angina.

Adult↗