Biomedical subjects

R Huang

Publications and source records attributed to R Huang.

At least 127 records · Page 7Linked to original sources

PubMed1996

Participation of individual brachial somites in skeletal muscles of the avian distal wing.

In this paper we investigate the somitic origin of the individual muscles of the forearm and hand using quail-chick chimeras. Our results show that only somites 16-21 give rise to wing muscle, but they take part in muscle formation to different extents. Somite 21 does not always participate in the formation of muscle of the forearm and hand. The most cranial somite (16) takes part in the radial muscles and the most caudal somites (20, 21) in the ulnar muscles, reflecting their position with respect to the limb bud. The centrally located somites (17, 18, 19) are involved in all (18) or most (17, 19) muscle primordia. This pattern of distribution is clearest in the forearm, whereas the participation of somites in particular muscle groups is not so distinct in the hand. Hand muscles are mainly made up of cells from somites 18-20. All brachial somites participate in dorsal (extensor) as well as ventral (flexor) muscles of the forearm and hand. Each somite takes part in more than three muscle primordia in a reproducible fashion, and every muscle primordium is derived from at least three somites. Especially the M. ulnimetacarpalis ventralis takes origin from all somites involved in limb muscle formation (16-21). Apart from muscle cells, endothelial cells also and a few fibroblasts of quail origin are found in the limb bud after somite grafting.

Age Factors↗

PubMed1996

Dietary marine lipids suppress continuous expression of interleukin-1 beta gene transcription.

n-3 Polyunsaturated fatty acids abundant in marine lipids suppress certain inflammatory and immune reactions, and dietary marine lipid supplements have antiinflammatory effects in experimental and human autoimmune disease. Previous work by other investigators demonstrated that dietary marine lipid supplements suppressed production of cytokines from stimulated human peripheral blood mononuclear cells ex vivo. The present study further documents the ability of n-3 fatty acids to inhibit cytokine formation, and in part defines the mechanism of the inhibition of production of interleukin-1 beta (IL-1 beta) by dietary n-3 fatty acid. Female BALB/c mice were each fed a fat-free balanced diet to which was added either a refined fish oil (FO) preparation as a source of n-3 fatty acid, or beef tallow (BT), which consisted primarily of saturated and monoenoic fatty acids. After ingesting the experimental diets for periods ranging from 3 to 12 wk. spleen cell preparations were stimulated ex vivo with either lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA), and proIL-1 beta mRNA (IL-1 beta mRNA) was measured by northern analysis. Levels of IL-1 beta mRNA in both LPS- and PMA-stimulated cells from BT-fed mice were elevated to a greater extent than in cells from FO-fed mice, at most concentrations of LPS and PMA. Stability of LPS-stimulated mRNA levels after actinomycin D was similar for BT and FO groups, indicating that lower levels of IL-1 mRNA with FO groups was related to suppressed IL-1 gene transcription and not due to accelerated transcript degradation. Nuclear run-on transcription assays revealed a more transient expression of the IL-1 beta gene in LPS-stimulated spleen cells from FO-fed mice compared to cells from BT-fed mice. We conclude that dietary marine lipids reduce transient expression of the IL-1 beta gene in stimulated splenic monocytic cells. Preliminary results from nuclear run-on transcription assays indicate that n-3 fatty acids may not change the initial rate of gene transcription but may promote more rapid shutting down of transcription of this gene after induction than do alternative lipids.

Animals↗

PubMed1996

Astrocyte-neuron interaction during one-trial aversive learning in the neonate chick.

During two specific stages of the Gibbs-Ng model of one-trial aversive learning in the neonate chick, we have recently found unequivocal evidence for a crucial involvement of astrocytes. This evidence is metabolic (utilization of the astrocyte-specific energy store, glycogen, during normal learning and inhibition of memory formation by the astrocyte specific metabolic inhibitors, fluoroacetate and methionine sulfoximine) as well as physiological (abolition of memory formation in the presence of ethacrynic acid, an astrocyte-specific inhibitor of cellular reaccumulation of potassium ions). These findings are discussed in the present review in the framework of a more comprehensive description of metabolic and physiological neuronal-astrocytic interactions across an interstitial (extracellular) space bounded by minute processes from either cell type.

Animals↗

PubMed1996

Leukotrienes do not regulate nitric oxide production in RAW 264.7 macrophages.

RAW 264.7 macrophages respond to lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) by producing large amounts of nitric oxide (NO) and prostaglandin E2 (PGE2), with maximal production 18-24 h after treatment. Following stimulation with the calcium inophore A23187, cultures of RAW cells also produce modest amounts of leukotrienes. However, the capacity of these cells to produce leukotrienes is transient, beginning 2 h after vehicle or LPS/IFN-gamma treatment, peaking by 4-6 h and absent by 8 h. A-79175, (R(+) N-[3-[5-(4-Fluorophenoxy)-2-furanyl]-1-methyl-2-propynyl]-N-hydroxyurea) a specific inhibitor of 5-lipoxygenase (5-LO), abolished leukotriene production by RAW cells in a dose-dependent, non-cytotoxic fashion while having no effect on PGE2 or NO production. By contrast, nordihydroguaiaretic acid (NDGA) inhibited production of leukotrienes, PGE2 and NO only at doses that were cytotoxic to the RAW cells. Exogenous leukotriene B4 (LTB4) had no effect on either NO or PGE2 production. An inhibitor of NO production, L-N-5-(1-iminoethyl) ornithine HCl (NIO) also did not affect leukotriene or PGE2 production, while dexamethasone blocked PGE2 and NO production, but did not affect leukotriene production in these cells. Taken collectively, these results indicate that there is no interaction between the pathways for leukotriene and nitric oxide production in RAW 264.7 macrophages.

Animals↗

PubMed1996

Hypertonic environment prevents depolarization and improves functional recovery from hypoxia in hippocampal slices.

Treatments that postpone hypoxic spreading depression (SD)-like depolarization (also called anoxic depolarization) facilitate recovery of function after transient cerebral hypoxia. Hypertonia reduces cerebral excitability, and we tested whether it also offers protection against SD-like depolarization and hypoxia. Oxygen was withdrawn from hippocampal slices bathed in normal artificial cerebrospinal fluid (ACSF) and, simultaneously, from slices cut from the same hippocampus but bathed in strongly hypertonic ACSF. Extracellular osmolarity (pi(o)) was increased by adding 100 mM mannitol or fructose to ACSF. Slices in normal pi(o) underwent SD-like negative extracellular voltage shift (delta Vo). The hypertonic slices usually showed no SD-like delta Vo but only a small, gradual negative voltage shift. Hypertonia also prevented the precipitate drop of interstitial calcium level ([Ca2+]o). When oxygenation and normal osmolarity were restored, synaptic transmission in the previously hypertonic slices recovered completely, but 3 h after reoxygenation orthodromically transmitted population spikes of the control slices recovered only 25.1% of the initial control amplitude. We conclude that hypertonic treatment during hypoxia improves subsequent recovery of synaptic function. The protection is probably due to the prevention of calcium uptake by blocking the SD-like depolarization, with the prevention of hypoxic cell swelling playing a lesser role.

Animals↗

PubMed1996

Neurofibrillary tangles in progressive supranuclear palsy contain the same tau epitopes identified in Alzheimer's disease PHFtau.

Neurofibrillary tangle (NFT)-rich brain samples from patients with progressive supranuclear palsy (PSP) or Alzheimer's disease (AD) were probed with a large panel of anti-tau antibodies to compare the species of tau present in PSP and AD NFTs by immunohistochemistry and Western blot methods. These antibodies have been shown to recognize phosphate-independent or -dependent epitopes that extend from the amino to the carboxy terminal domains of normal brain tau and the abnormal tau in the paired helical filaments (PHFs) of AD NFTs (PHFtau). The immunohistochemical studies showed that all of the tau epitopes detected in brainstem PSP NFTs also were found in hippocampal AD NFTs and vice versa. While Western blots demonstrated 2 PHFtau-like immunobands in PSP brainstem, a triplet of PHFtau proteins were seen in the AD and PSP hippocampus. Despite differences in the distribution, ultrastructure and immunoblot profile of NFTs in PSP and AD, the same constellation of tau epitopes is present in the abnormal tau proteins in PSP and AD NFTs. Thus, the generation of abnormal tau proteins in PSP (PSPtau) and AD (PHFtau) may have similar adverse biological consequences in both diseases.

Aged↗

PubMed1996

Physical association of starch biosynthetic enzymes with starch granules of maize endosperm. Granule-associated forms of starch synthase I and starch branching enzyme II.

Antibodies were used to probe the degree of association of starch biosynthetic enzymes with starch granules isolated from maize (Zea mays) endosperm. Graded washings of the starch granule, followed by release of polypeptides by gelatinization in 2% sodium dodecyl sulfate, enables distinction between strongly and loosely adherent proteins. Mild aqueous washing of granules resulted in near-complete solubilization of ADP-glucose pyrophosphorylase, indicating that little, if any, ADP-glucose pyrophosphorylase is granule associated. In contrast, all of the waxy protein plus significant levels of starch synthase I and starch branching enzyme II (BEII) remained granule associated. Stringent washings using protease and detergent demonstrated that the waxy protein, more than 85% total endosperm starch synthase I protein, and more than 45% of BEII protein were strongly associated with starch granules. Rates of polypeptide accumulation within starch granules remained constant during endosperm development. Soluble and granule-derived forms of BEII yielded identical peptide maps and overlapping tryptic fragments closely aligned with deduced amino acid sequences from BEII cDNA clones. These observations provide direct evidence that BEII exits as both soluble and granule-associated entities. We conclude that each of the known starch biosynthetic enzymes in maize endosperm exhibits a differential propensity to associate with, or to become irreversibly entrapped within, the starch granule.

1,4-alpha-Glucan Branching Enzyme↗

PubMed1996

An apparent functional correlation between variations in amino acid residues in HLA-DR4.1 and 4.2 serological subtypes and oligonucleotide characterization.

HLA-DR4 can be subdivided serologically into two specificities, DR4.1 and DR4.2, using well-defined monospecific alloantisera used in the 11th International Histocompatibility Workshop. In this study, a total of 1095 random DR4-positive individuals from several ethnic groups were tested first for serotype DR4.1/4.2 and then for DRB1*04 alleles using polymerase chain reaction (PCR) followed by sequence-specific oligonucleotide probe hybridization (SSOPH). An almost 100% correlation between samples testing positive for DR4.1 and the presence of alanine at position 74 was observed, while samples testing positive for DR4.2 correlated with the presence of glutamic acid at position 74. DRB1*04 alleles 0401, 0402, 0404, 0405, 0408, 0409 and 0410 are aligned in functional groups which coincide with the serological subtype of DR4.1. DRB1*04 alleles 0403, 0406, 0407 and 0411 coincide with subtype DR4.2. Amino acid substitutions at positions 57, 71 and 86 indicate other significant variations between alleles within the serological subgroup of DR4.1 and define five minor subgroups. The serologic and oligonucleotide allelic subgroups are in turn correlated with recognized cellular Dw antigens. While sequence data provide evidence of structural differences, data on cellular antigens support a functional association between these designated groups and their significance in transplantation and GVHD. Testing results are categorized by ethnic group in order to establish frequency data for donor selection criteria.

Amino Acid Sequence↗

PubMed1996

Function of somite and somitocoele cells in the formation of the vertebral motion segment in avian embryos.

We have studied the distribution of thoracic somite and somitocoele-derived cells using homotopical grafting between quail and chicken embryos and reincubation periods of 2-6 days. Serial sections were evaluated with antibodies against quail cells, quail hemangiopoietic cells and desmin. With the exception of neural crest cells in the cranial sclerotome half, all cells of the operated segment are quail cells derived from a single somite. These cells differentiate into sclerotome, myotome and the anlage of the dermis of the back. After longer reincubation periods, the somite-derived quail cells form the neighboring halves of 2 adjacent vertebral bodies and the intervening (disc-homologous) tissue. Resegmentation is furthermore visible in the lamina and the spinous process. Somite cells also form the articular and transverse processes, and the intertransverse muscle including its insertion to the next cranial transverse process. One thoracic somite forms the proximal part of 1 rib. In more distal parts, 1 somite forms the cranial half of 1 rib and the caudal half of the next cranial rib, and the intercostal muscle and part of the connective tissue. Somite-derived quail cells are found in muscle that bridges over 2 segments cranial and caudal from the operated segment. The craniocaudal distribution of endothelial cells is approximately the same. Somitocoele cells that are located centrally in the epithelial somite express the sclerotome-markers Pax-1 and Pax-9. After 2-3 days of reincubation, grafted thoracic somitocoele cells are found mainly in the cranial part of the caudal sclerotome half. They form an area representing the anlagen of the intervertebral disc and the rib. After longer reincubation periods, the grafted quail somitocoele cells form the intervertebral disc-homologous tissue and the proximal part of the rib. In more distal parts of the rib they are located in the cranial half of 1 rib and the caudal half of the next cranial rib. The somitocoele cells also form the surface of the intervertebral joint, and give rise to a small number of endothelial cells that are found up to 1 segment cranial and caudal to the operation site. Our studies show that resegmentation is found in most parts of the vertebra and in the distal ribs. One somite forms the origin and insertion of the segmental muscle. Therefore, the somite can be regarded as the ancestor of the vertebral motion segment. Somitocoele cells are located centrally both in the epithelial somite and in the vertebral motion segment.

Animals↗

PubMed1996

[Pharmacokinetic study of intraperitoneal chemotherapy with high-dose cisplatin for advanced ovarian cancer].

OBJECTIVE: To determine the characteristics of pharmacokinetics with high-dose cisplatin (DDP) instilled intraperitoneally and its toxicity as compared with that by intravenous (i.v.) route of administration (i.p.). METHODS: Sixteen patients with advanced ovarian cancer, not previously treated, were randomly divided into two groups: every patient in group I received intraperitoneal administration of DDP (100mg/m2) and those in group II received the same dose of DDP by intravenous route. The blood, ascitic fluid and urine were collected in different intervals as scheduled for 8 days after administration of these drugs. The total platinum of all samples were measured by a flameless type of atomic absorption spectrometry. RESULTS: The concentration of total platinum in the ascitic fluid was very high in i.p. group. The area under the concentration-time curve (AUC) for total platinum in ascitic fluid after i.p. therapy was 5 folds greater than that after i.v. therapy (P < 0.05). The total platinum concentration in serum after i.p. therapy was about the same as that after i.v. therapy. The half-life time for the elimination phase of total platinum from ascitic fluid and serum after i.p. administration was longer than that after i.v. administration. The toxicity of high-dose DDP given i.p. was not increased as compared with that given i.v.. CONCLUSIONS: This study indicates that high-dose DDP i.p. therapy offers some advantages in the treatment of ovarian cancer. The tumor tissues and peritoneal growths could be bathed in a high concentrations of DDP with a longer duration, so that the tumorcidal effect may be increased. The drug concentration in serum after i.p. therapy was as high as i.v. route. The toxicity of high-dose DDP i.p. therapy was not higher than that of i.v. therapy.

Adult↗

PubMed1996

Management of ovarian endodermal sinus tumor.

OBJECTIVE: To evaluate the role of combination chemotherapy and the optimal cycles of treatment in improving the prognosis of ovarian endodermal sinus tumor, and to study the relationship between the type of surgical management and the outcome of the disease. PATIENTS AND METHOD: Sixty-three patients with ovarian endodermal sinus tumor were divided into 3 groups according to the postoperative chemotherapy they had received. Group 1 (37 patients) patients were treated with at least 6 cycles of VAC (vincristine, actinomycin-D and cytoxan) or 4 cycles of PVB (cysplatin, vincristine and bleomycin). Group 2 (17 patients) patients were treated with VAC in less than 6 cycles or PVB in less than 4 cycles. Group 3 (9 patients) patients received no VAC or PVB but some other drugs like TSPA, 5FU, MTX and cytoxan in various combinations. The sustained remission rates and survivals were compared among these 3 groups. For patients with full courses of treatment with VAC or PVB (Group 1), different types of surgical management were studied about their relationship with the outcome of the disease. RESULTS: The persistent remission rates are 81.8%, 23.5% and 11.8% for group 1, group 2 and group 3 patients respectively (P < 0.001). The survival curve of group 1 is very much different from that of group 2 and group 3 patients. With full courses of chemotherapy with VAC or PVB, it appears that the different types of surgical managements (unilateral vs bilateral adenectomy; with vs without systemic lymphadenectomy; residual tumor < 2 cm vs > 2 cm) did not show definite relationship with the outcome of the disease. CONCLUSION: Combination chemotherapy with VAC or PVB dramatically improved the prognosis of ovarian endodermal sinus tumor but it should be emphasized that the favorable results could be obtained only when the treatment is given on time and in optimal cycles. Although ovarian endodermal sinus tumor is chemosensitive, appropriate surgical treatment is still important, however, the surgical techniques need some further studies.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1996

[Studies on strategies for changing food composition of residents based on their nutritional status].

Investigations of resident food consumption and evaluations of their dietary nutrition were carried out to correctly lead to the adjustment of food composition, promotion of coordinating development of food consumption and production, and continuous improvement of people's nutritional level and health status. Results showed that residents consumed less protein of high quality, more fat in the urban area, insufficient some trace element and more salt in Hebei province. Based on these facts, it is recommended that to consume vegetable food as major dietary composition with a variety of grains and vegetables, to increase adequately animal food and legumes, to decrease salt intake, and to lower fat intake in the urban areas be the strategic goals for the food composition changes. Measures to implement these goals are discussed in the paper, also.

China↗

PubMed1996

[Carcinogenic mechanisms of multiple genes in cervical carcinoma].

The alterations of multiple genes and their carcinogenic mechanism in cervical carcinoma were studies by molecular hybridisation, PCR and PCR-ASO techniques. The G-T point mutation in the 12th coden of Ha-ras was detected in cervical carcinomas with mutation frequency of 18.2% (8/44), and the amplification rate of Ha-ras gene was 45% (9/20). The c-erb B2 was amplified 3-30 fold with an amplification rate of 73.3% (11/15) in cervical carcinomas and 5 cancerous samples showed gene rearrangement. The elevated copies of c-myc gene with amplification rate of 91.7% (11/12) were observed in cervical carcinomas. The study of HPV16 viral gene showed that the existence of HPV16 DNA sequence was positively associated with c-myc gene amplification in cervical cancerous samples. The p53 and Rb tumor suppressor genes absence of deletion were observed in the 12 specimens of cervical carcinoma investigated. As mentioned above, the study on alteration and carcinogenic mechanism of multiple genes indicated that 3 oncogenes and HPV16 viral gene were activated or integrated throygh different mechanisms and they played roles in co-carcinogenesis. The integration of HPV16 gene might promote the c-myc gene at the early stage in carcinogenesis of cervical carcinoma, while the alteration of Ha-ras and c-erb B2 gene might be middle-late event. As for the roles of the p53 and Rb tumor suppresor gene in cervical carcinogenesis need further researches.

Carcinoma, Squamous Cell↗

PubMed1996

[Single-dose intramuscular methotrexate for treatment of ectopic pregnancy].

OBJECTIVE: The efficacy and indication of single-dose intramuscular methotrexate to treat early ectopic pregnancy were explored. METHODS: 27 cases of ectopic pregnancy were treated by single-dose intramuscular methotrexate (50 mg/m2) without citrovorum rescue. The beta-hCG was monitored regularly till it became normal. Twelve of them recieved this regimen in outpatient service. RESULTS: 24 cases (88.9%) were successfully treated. Three failed and switched to operation. There were no significant differences (P > 0.05) in gestational age and size of adnexa ectopic mass between successful cases and failed cases, but highly significant differences (P < 0.01) in occurrence rate of abdominal pain and beta-hCG titers before treatment. CONCLUSION: The early diagnosis and adherence to strict criteria are the keys to successful management. No abdominal pain, ectopic mass < or = 5 cm in greatest dimension and titer of serum beta-hCG < 6000 IU/L were mainly indications of drug treatment.

Adult↗

PubMed1996

[Management and prognosis of advanced ovarian cancer associated with bowel metastasis and obstruction].

OBJECTIVE: To investigate the high risk factors and prognostic factors of bowel metastasis and obstruction in the patients with late stage ovarian cancer by analyzing the clinical characteristics and to find out appropriate methods to solve this difficult problem. METHODS: 151 cases with ovarian cancer in stages I and IV who received the treatment from January 1, 1988 to December 31, 1992 were analyzed retrospectively. RESULTS: Operative residues, diffuse bowel metastasis, small intestinal involvement and papillary serous cystadenocarcinoma were found to be high risk factors for bowel obstruction. Age, duration between operation and obstruction, level of CA125 at occurrence of obstruction, numbers of operation and the histologic grade were disclosed as prognostic factors. The prognosis was much worse if the score is more than 6. CONCLUSION: Due attention paid to the high risk factors and the prognostic factors should be emphasized to improve the quality of life and the survival rate.

Adolescent↗

PubMed1996

[Diagnosis and management strategies of hereditary ovarian cancer syndrome].

OBJECTIVE: To describe the clinical profile of hereditary ovarian cancer syndrome (HOCS), focusing on the diagnosis and management strategies. METHOD: Eight patients from four families were identified with HOCS. The diagnosis was made by pedigree according to the criteria recommended by Lynch. Clinical manifestations and management strategies were discussed. RESULT: The incidence of epithelial ovarian cancer in HOCS family women was 20% which was higher than that in sporadic ovarian cancer (10%) (P < 0.05). The mean onset age in patients with HOCS was 41.6% years which was younger also than that in sporadic ovarian cancer. Serous cystadenocarcinoma was the predominant histological type of the HOCS, and the prognosis seems to be better. CONCLUSION: Women in families with HOCS are in a population of high risk for epithelial ovarian cancer. Management strategies should include periodical counselling, screening and surveillance. For women with established families, above 40 years of age and identified with HOCS or with histories of breast or colorectal cancer, prophylactic oophorectomy should be considered.

Adult↗

PubMed1996

[An observation of the effect of tanshinone on cancer cell proliferation by Brdu and PCNA labeling].

The aim of this study was to find out the anti-cancer activity of Tanshinone and its mechanism of action. Human hepatic carcinoma cell line (SMMC-7721) and leukemia cell line (HL60) were treated with tanshinone the cancer cell proliferation indices were measured by Brdu Labeling and immuno-histochemical stain of PCNA. The Brdu labeling rates of human hepatic carcinoma and leukemia cells treated with tanshinone were 8.95% and 19.01%, which were lower than those of controls (28.0%, 25.57%) respectively (P < 0.01), PCNA positive rates were 57.0% and 30.32%, which were significantly lower than those of controls (74.3%, 47.05%) (P < 0.01). The results indicate that Brdu labeling and PCNA detection may have important utility in the studies of tumor cell proliferation and the relative factors affecting the cell proliferation. The inhibitory effect of tanshinone on cancer cell proliferation might be associated with inhibiting DNA synthesis, PCNA expression and activity of DNA polymerase delta of the tumor cells.

Abietanes↗

PubMed1995

The effect of graded hypertonia on interstitial volume, tissue resistance and synaptic transmission in rat hippocampal tissue slices.

Rat hippocampal slices were exposed for 30 min to each of three levels of increased osmolarity (pi o), achieved by adding 25, 50 or 100 mM mannitol to the bathing solution. The interstitial volume (ISV) determined as the relative volume of dilution of the probe ion, tetra-methyl-ammonium (TMA+), increased markedly, indicating cell shrinkage. Tissue resistance (Ro) decreased only slightly with increasing pi o. The discrepancy between ISV increase and Ro decrease suggests increased electrical resistance of cell membranes. TMA+ dilution appears to be a more reliable measure of ISV than is Ro. During recovery from hypertonic treatment the previously expanded ISV frequently shrank, suggesting post-hypertonic cell swelling. Hypertonic treatment significantly depressed orthodromically transmitted population spikes and extracellular synaptic potentials (fEPSPs), and the degree of depression varied with the increase in pi o. Changing recording condition due to reduced Ro could not account for the depression of population spikes and fEPSPs. Following return to normal pi o, orthodromic population spikes frequently overshot initial control amplitude. An isolated episode of spreading depression occurred in about half of the slices following exposure to the most severely hypertonic solution. At the end of 2.5 h recovery, orthodromic spikes did not significantly differ from those of untreated control slices observed for the same length of time. We conclude that synaptic transmission is depressed by elevation of pi o, and the depression is concentration dependent and reversible.

Animals↗