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Biomedical subjects

H Long

Publications and source records attributed to H Long.

At least 37 records · Page 2Linked to original sources
PubMed1997

Rat osteoblast and osteosarcoma nuclear matrix proteins bind with sequence specificity to the rat type I collagen promoter.

The nuclear matrix mediates the 3-dimensional organization of DNA and supports DNA replication and its transcription. We hypothesize that the osteoblast nuclear matrix contributes to the transcriptional control of type I collagen (COL1A1) expression. Cis-regulatory elements of the rat COL1A1 promoter that control osteoblast expression in vivo are between -2.3 and -1.67 kilobase pairs (kb) but lie within -3.5 and -2.3 kb in cultured bone cells. This may result from differences in cell architecture between osteoblasts in tissue and those in vitro. Our aim was to identify osteoblast nuclear matrix proteins (NMPs) that associated with sequence-specificity to the COL1A1 promoter. We used osteoblasts from the rat metaphyseal femur and the rat osteosarcoma cells, ROS 17/2.8. Nuclear matrix and soluble nuclear proteins were obtained as separate subfractions. Gel mobility shift analysis, using fragments of the COL1A1 promoter, was used to identify DNA-binding proteins in the nuclear subfractions. A NMP-DNA interaction, NMP3, was observed between -2149 and -2106 nucleotide in both osteoblasts and osteosarcoma cells. NMP4 was detected between -3518 to -3406 nucleotide. Therefore, osteoblast NMPs recognize sequences in regulatory regions of the COL1A1 promoter and may link cell structure and the transcriptional regulation of this protein.

Animals↗
PubMed1997

Locomotion on the water surface: propulsive mechanisms of the fisher spider

Using kinematic and mechanical experiments, we have shown how fisher spiders, Dolomedes triton (Araneae, Pisauridae), can generate horizontal propulsive forces using their legs. This horizontal thrust is provided primarily by the drag of the leg and its associated dimple as both move across the water surface. Less important sources of resistance are surface tension and bow waves. The relative contributions of drag, surface tension and bow waves were examined in several different ways. In one experiment, we measured the forces acting on a leg segment as water flowed past it in non-turbulent flow; the bow wave was not present at leg relative velocities below 0.2ms-1 and thus cannot play a role in thrust production at low leg speeds. In a second experiment, we varied the surface tension by altering the concentration of ethanol from 0% to 9% in the experimental water tank. At a constant dimple depth, force varied little with changes in surface tension, a result consistent with the hypothesis that drag is the primary source of resistance. In addition, however, as surface tension decreased from 0.072 to 0.064Nm-1, the power exponent of the relationship between force and velocity (as measured by the exponent of the power function relating the two variables) increased; at lower surface tensions, down to 0.054Nm-1, the power exponent of the relationship between force and velocity decreased. These results suggest an influence of surface tension (albeit still secondary to drag) in generating horizontal resistance to leg movement. We also measured flow disturbance in the water downstream from a leg segment and confirmed that, even at velocities well below 0.2ms-1, the leg-cum-dimple transferred momentum to the water, which is a clear indication that drag is a contributor to the resistance encountered by a spider's leg. Finally, modeling the leg-cum-dimple as a circular cylinder generates values of drag that account for 75­98% of the measured leg force when the dimple is 0 or 1mm deep. These results not only elucidate the primary mechanism of propulsion for D. triton and other similar-sized arthropods, such as adult water striders (Gerridae), but also suggest that the formerly enigmatic locomotion of very small water-walking organisms (e.g. first-instar water striders) can be understood in the same way.

Journal Article↗
PubMed1997

Effects of removing circulatory tumor necrosis factor by immunoadsorption on experimental endotoxin shock animals.

OBJECTIVE: To evaluate the effects of removing circulatory tumor necrosis factor (TNF) by immunoadsorption on endotoxin shock animals. METHODS: Sixty New Zealand white rabbits were injected intravenously with lethal dose of endotoxin (10 Billion cfu/kg E. Coli endotoxin) and randomly divided into 3 groups: perfusion group, hemoperfusion started at 1 hour after injecting endotoxin through immunoadsorbent columns against TNF; pseudoperfusion group, hemoperfusion through blank columns; and control group, injected with endotoxin only. The arterial pressure, microcirculation of the mesentery, plasma levels of TNF, IL-1, IL-6, IL-8, nitrite, endothelin-1 (ET-1), alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine were measured and analyzed and finally the survival rate was observed. RESULTS: Plasma levels of TNF were sharply reduced after immunoadsorption. Moreover, release of IL-1, IL-6, IL-8, NO and ET-1 were also attenuated. Hemodynamic abnormalities could be improved and survival rate ameliorated significantly. CONCLUSION: Specific immunoadsorption of circulating TNF might be a new and effective therapy for endotoxin shock.

Animals↗
PubMed1997

[Therapeutic effect of Chinese medicinal herbs combined with chemotherapy on advanced non-small cell lung cancer].

OBJECTIVE: To observe the effect of Chinese medicinal herbs (CMH) and chemotherapy on non-small cell lung cancer. METHODS: Comparing the therapeutic effects of three treatment regimens on 58 advanced non-small cell lung cancer (NSCLC) patients who were treated with CMH plus chemotherapy (CT), 28 cases treated with CT only, and 24 cases treated with CMH alone. RESULTS: Effective rates (partial remission + complete remission) were 22.9% in CMH + CT group, 13.6% both in CT and in CMH group. There were no significant differences between these three groups according to the short-term results (P > 0.05). Mean survival time (month) for CMH + CT, CT and CMH groups were 10.2, 5.3 and 8.0 respectively. The survival rate (Kaplan Meicr method) of both CMH + CT and CMH group were significantly higher than that of CT group (P < 0.01, P < 0.05) but no significant difference between CMH and CMH + CT group (P > 0.05). CONCLUSION: Chinese medicinal herbs were helpful to improve median survival time and survival rate of patients with advanced NSCLC.

Adult↗
PubMed1996

Adjuvant chemotherapy versus chemotherapy plus pelvic irradiation for high-risk cervical cancer patients after radical hysterectomy and pelvic lymphadenectomy (RH-PLND): a randomized phase III trial.

OBJECTIVE: To compare the clinical efficacy of adjuvant chemotherapy a lone vs chemotherapy plus whole pelvic radiation therapy (RT) on recurrence rates, patterns of recurrence, and survival of patients post-RH-PLND for cervical cancer at high risk for recurrence. METHODS: Prospective multicenter randomized Phase III trial. Patients with Stage IB-IIA cervical cancer undergoing RH-PLND were eligible. Risk factors include deep cervical invasion, tumor > or = 4 cm, parametrial involvement, nonsquamous histology, and/or pelvic lymph node metastasis. Chemotherapy consisted of cisplatin and bleomycin, alone or in combination with whole pelvic RT. Survival was determined by Kaplan-Meier estimate. RESULTS: Eighty-nine patients were entered from 1987 to 1994. Seventy-five patients had a Stage IB cancer and 14 patients had Stage IIA. Twenty-five patients had > or = 3 risk factors. Forty-four patients received chemotherapy alone vs 45 patients treated with chemotherapy and RT. Nineteen patients had recurrences and 16 patients have died. Nine of 44 (20%) patients receiving chemo alone recurred compared to 10/45 (22%) patients receiving chemo and RT (P=ns). Patterns of recurrence were statistically similar between the two treatment arms, even among the subgroup of patients with > or = 3 risk factors. Both regimens were well tolerated. CONCLUSION: CT + RT did not prove a superior adjuvant therapy for patients at high risk of recurrence after RH-PLND for early cervical cancer in this limited trial. Recurrence rates and patterns of recurrences (local, regional, or distant) were not influenced by the addition of RT.

Adult↗
PubMed1996

Surgical outcome after repeated transsphenoidal surgery in acromegaly.

Transsphenoidal selective adenomectomy is the most efficient primary treatment for acromegaly. However, management of persistent or recurrent disease remains controversial. The objective of the present study was to evaluate the early and long-term efficacy and safety of a second transsphenoidal surgery performed in those cases. The results of a retrospective study of 16 patients undergoing reoperation by the senior author (J.H.) between 1970 and 1991 are reported. Reoperation was performed for persistent or progressive acromegaly in 11 patients, visual impairment in four, and disease recurrence in one. Normalization of growth hormone (GH) was defined as a basal GH level of less than 5 micrograms/L and suppression to less than 2 micrograms/L during the oral glucose tolerance test. Long-term follow-up data were available in 15 patients. The second transsphenoidal surgery induced a greater than 50% decrease of GH level in 11 patients. Three (19%) of 16 patients were cured according to the authors' criteria and remained so after 2, 7, and 20 years. Two more patients had a postoperative basal GH level of less than 5 micrograms/L but incomplete suppression during the oral glucose tolerance test. Thus, a total of five patients (31%) achieved a basal GH of less than 5 micrograms/L. One other patient who had no initial improvement after the second transphenoidal surgery had spontaneous normalization of his GH level after 13 years. The following complications of the second surgery occurred in three patients: one subarachnoid hemorrhage, two new visual field defects, one cranial nerve palsy, and one meningitis. Moreover, 10 patients (62.5%) developed one or more new pituitary hormone deficiencies. In conclusion, reoperation for persistent or recurrent acromegaly has low success and high complication rates. According to the authors' experience, this procedure should be reserved for patients unresponsive to other forms of therapy or with progressive visual impairment despite medical therapy.

Acromegaly↗
PubMed1996

CD3 gamma, CD3 delta, and CD3 zeta mRNA in adult human marrow hematopoietic progenitors correlates with surface CD2 and CD7 expression.

Hematopoietic stem cells from adult marrow, cord blood, or fetal liver can differentiate into myeloid and lymphoid lineages. Early steps in this differentiation process are not yet fully understood. To correlate surface antigen expression with molecular events occurring during early lymphopoietic differentiation, we examined CD3 gamma, CD3 delta, and CD3 zeta gene expression in adult human CD34+ marrow progenitors and their subsets. Purification by fluorescence-activated cell sorter (FACS) was used to obtain 1) a CD34+ Lin-DR- population known to contain primitive, uncommitted progenitors; 2) CD34+/CD7+/CD2+ and 3) CD34+/CD7+/CD2+ cells expressing receptors associated with natural killer (NK) cell or T cell lineage commitment. We demonstrate that CD34+Lin-DR- cells do not contain CD3 gamma, CD3 delta, or CD3 zeta transcripts, consistent with the primitive uncommitted nature of progenitors in this cell population. Expression of the CD34+/CD7+/CD2- phenotype correlates with the transcription of CD3 zeta but not CD3 gamma or CD3 delta, a pattern of transcription observed in mature blood NK but not T cells. Expression of both CD7 and CD2 on CD34+ cells is associated with not only CD3 zeta gene transcription but also CD3 gamma and CD3 delta, a pattern found in T cells but not mature NK cells. We have identified unique patterns of mRNA transcription in phenotypically distinct lymphoid progenitors found in the marrow. These findings raise the possibility that although primitive NK and T cell progenitors share a common differentiation pathway, divergent NK and T lineage commitment steps may occur very early in lymphopoiesis. Our findings suggest that application of in vitro marrow and thymus culture techniques may be utilized to more fully describe commitment and differentiation of early lymphoid progenitors and define the role of the microenvironment in this process.

Adult↗
PubMed1995

The phylogenetic positions of the conifer genera Amentotaxus Phyllocladus, and Nageia inferred from 18S rRNA sequences.

To determine the evolutionary positions of the conifer genera Amentotaxus, Phyllocladus, and Nageia, we obtained 18S rRNA sequences from 11 new taxa representing the major living orders and families of gymnosperms. With the published Chlamydomonas as an outgroup, phylogenetic analyses of our new data and available sequences indicate that (1) the Gnetales form a monophyletic group, which is an outgroup to the conifers, (2) the conifers are monophyletic, (3) Taxaceae, Cephalotaxaceae, Cupressaceae, and Taxodiaceae form a monophyletic group, (4) Amentotaxus is closer to Torreya than to Cephalotaxus, suggesting that Amentotaxus is better to be classified as a member of Taxaceae, (5) Phyllocladus, Dacrycarpus, Podocarpus, and Nageia form a monophyletic group, and (6) Pinaceae is an out-group to the other families of conifers. Our finding that Phyllocladus is a sister group of the Podocarpaceae disagrees with the suggestion that the phylloclade of the genus is an ancient structure and that the genus is a terminal taxon within the Podocarpaceae. The genus Nageia is more closely related to Podocarpus than to Dacrycarpus and was derived from within the Podocarpaceae. In conclusion, our data indicate that in conifers, the uniovulate cone occurred independently in Taxacaeae and Cephalotaxaceae, and in Podocarpaceae after the three families separated from Pinaceae, and support the hypothesis that the uniovulate cone is derived from reduction of a multiovulate cone.

DNA, Complementary↗
PubMed1995

[A study on recovery of recurrent laryngeal nerve defect by degenerative skeletal muscle bridge with vascular implantation].

The dog's recurrent laryngeal nerve defect (1cm) was repaired by near vessels implantation of heat denaturation muscles as a bridge. Three months after operation, regenerative nerve neurite smoothly passed through muscle bridge, grew into distal isogenous nerves and formed function joint. The implanted vessels grew and branched in the muscle bridge. Six months later, the motor end plates of caryngeal muscle grew well, laryngeal electromyography showed that nerves contraction of laryngeal muscles built. Laryngoscopy showed that vocal cord moved to the normal position. The voice perfectly recovered.

Animals↗
PubMed1994

1H-magnetic resonance spectroscopy of the left temporal and frontal lobes in schizophrenia: clinical, neurodevelopmental, and cognitive correlates.

Twenty eight schizophrenic patients and 20 normal volunteers underwent proton magnetic resonance spectroscopy (MRS) on the left temporal and frontal lobe regions. Male patients showed a significant reduction in frontal but not temporal n-acetylaspartate (an intraneuronally distributed metabolite) in comparison with either male controls or female patients; frontal choline was raised in male patients relative to these groups. Putative neurodevelopmental indices, including obstetric complications, family history of schizophrenia, and minor physical anomalies, proved unrelated to MRS resonances. However, multiple aspects of memory function in patients were related to temporal but not frontal creatine, a pattern that was not apparent among controls. These MRS findings complement some previous structural MRI studies and much clinical and epidemiological evidence of important gender differences in schizophrenia. The findings also suggest that memory dysfunction in patients with schizophrenia may be associated with a particular pattern of temporal lobe metabolism on MRS.

Adult↗
PubMed1993

The phylogenetic position of Taxaceae based on 18S rRNA sequences.

The evolutionary position of the yew family, Taxaceae, has been very controversial. Some plant taxonomists strongly advocate excluding Taxaceae from the conifer order and raising its taxonomic status to a new order or even class because of its absence of seed cones, contrary to the case in the majority of conifers. However, other authors believe that the Taxaceae are not fundamentally different from the rest of the conifers except in that they possess the most reduced solitary-ovule cones. To resolve the controversy, we have sequenced the 18S rRNA genes from representative gymnosperms: Taxus mairei (Taxaceae), Podocarpus nakaii (Podocarpaceae), Pinus luchuensis (Pinaceae), and Ginkgo biloba (Ginkgoales). Our phylogenetic analysis of the new sequence data with the published 18S rRNA sequence of Zamia pumila (a.cycad) as an outgroup strongly indicates that Taxus, Pinus, and Podocarpus form a monophyletic group with the exclusion of Ginkgo and that Taxus is more closely related to Pinus than to Podocarpus. Therefore, Taxaceae should be classified as a family of Coniferales. Our finding that Taxaceae, Pinaceae, and Podocarpaceae form a clade contradicts both the view that the uniovulate seed of Taxaceae is a primitive character and the view that the Taxaceae are descendants of the Podocarpaceae. Rather, the uniovulate seed of Taxaceae and that of some species of Podocarpus appear to have different origins, probably all reduced from multiovulate cones.

Base Sequence↗
PubMed1992

Acetazolamide in hemodialysis patients: a rational use after ocular surgery.

Acetazolamide is a weak diuretic used to decrease production of aqueous humor in the eye. Hemodialysis patients undergoing ocular surgery may benefit from acetazolamide; however, no pharmacokinetic data are available for this group of patients. We report a patient who received acetazolamide 250 mg every 6 hours after ophthalmic surgery and developed reversible neurological side effects associated with very high plasma concentrations. Using pharmacokinetic analysis, we suggest an alternate administration of acetazolamide for end-stage renal patients.

Acetazolamide↗
PubMed1987

Coronary bypass without angiography: an unusual circumstance.

This paper presents an unusual case of an individual with myocardial ischemia, angina pectoris, and myocardial infarction who also had an anaphylactic reaction to angiographic dye. The coronary bypass operation was guided by the use of intraoperative coronary reactive hyperemia assessed by Doppler ultrasound. The patient has had a good response to the operation without additional angina or difficulties.

Angina Pectoris↗
PubMed1979

Pulmonary sporotrichosis in Oklahoma in susceptibilities in vitro.

Six cases of pulmonary sporotichosis were observed in 2 institutions in Oklahoma City, Okla. Three of the patients were treated with iodides with or without surgery. Although one patient required a second course of iodides, the patients have remained well after at least 34 months of follow-up. Three patients treated with amphotericin B, single course as well as multiple courses, and other antifungal agents (hydroxystilbamidine and miconazole) have all relapsed. These cases and a reviewed of more than 40 cases of pulmonary sporotrichosis susceptibilities of Sporothrix schenckii that we observed in vitro suggest that amphotericin B is not an effective agent for the treatment of pulmonary sporotrichosis. It is our opinion that the treatment of choice for pulmonary sporotrichosis is a supersaturated solution of potassium iodide. If the patient is allergic to the medication or fails to respond, then a combination of amphotericin B plus flucytosine may be tried.

Adult↗