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1.
It may be difficult to differentiate between cells of parathyroid and thyroid origin in ultrasound-guided fine needle aspirations of the neck region, even in patients with a clinical history of hyperparathyroidism. A parathyroid hormone antibody was used in an immunohistochemical system to confirm a parathyroid origin in fine needle aspirate smears from nine patients with hyperparathyroidism. Immunoperoxidase positivity for parathyroid hormone confirmed a parathyroid origin in six of nine cases and was strongly suggestive, although equivocal, in the remaining three cases. Technical problems included nonuniform staining and background staining.  相似文献   
2.
We have used the human globin locus control region (LCR) to assemble an expression system capable of high-level, integration position-independent expression of heterologous genes and cDNAs in murine erythroleukaemia (MEL) cells. The cDNAs are inserted between the human beta-globin promoter and the second intron of the human beta-globin gene, and this expression cassette is then placed downstream of the LCR and transfected into MEL cells. The cDNAs are expressed at levels similar to those of the murine beta-globin in the induced MEL cells. Heterologous genomic sequences can also be expressed at similar levels when linked to to the LCR and beta-globin promoter. In addition we demonstrate that, after induction of differentiation, MEL cells are capable of secreting heterologous proteins over a prolonged time period, making this system suitable for use in continuous production systems such as hollow fibre bioreactors. The utility of the LCR/MEL cell system is demonstrated by the expression of growth hormone at high levels (greater than 100 mg/l) 7 days after induction. Since the expression levels seen do not depend upon gene amplification and are independent of the integration position of the expression cassette, it is possible to obtain clones with stable high-level expression within 3-4 weeks after transfection.  相似文献   
3.
A radiochemical assay has been developed for a NADP+-specific gamma-glutamate semialdehyde dehydrogenase from rat intestinal epithelial cells. The spectrophotometric assay utilized to measure the enzyme in bacterial cell homogenates is not sensitive enough for homogenates from rat mitochondria, which require an assay that can measure as little as 0.5 nmol NADPH formed/min/ml extract. The assay described here is sensitive to 0.1 nmol product formed/min/ml of extract and employs the use of [3H]pyrroline 5-carboxylate which is phosphorylated and oxidized by the enzyme to gamma-[3H]glutamyl phosphate, a product that decomposes to [3H]pyrrolidone 5-carboxylate. The latter product is separated from the substrate by ion-exchange chromatography. In order to correct for any product loss during separation by ion-exchange [14C]pyrrolidone 5-carboxylate is added as an internal standard to the deproteinized assay mixture. Under the assay conditions described mammalian gamma-glutamate semialdehyde dehydrogenase activity is linear with respect to time and protein concentration. Comparison between the kinetic parameters reported for the bacterial enzyme and those reported here for the mammalian enzyme indicate similarities in the pH optima as well as a requirement for phosphate. Kinetic studies on mammalian enzyme yield apparent Km values of 1.8 mM for pyrroline 5-carboxylate, 0.2 mM for NADP+, and 11.3 mM for phosphate.  相似文献   
4.
Plasma catecholamine levels during water immersion in man   总被引:1,自引:0,他引:1  
In ten normal subjects thermoneutral neck-out water immersion produced a highly significant natriuresis and diuresis mediated via an induced central hypervolaemia. During immersion suppression of plasma noradrenaline and adrenaline was observed but no change occurred in plasma dopamine levels. No correlation was found between the suppression of noradrenaline and the diuresis and natriuresis. The reduction in plasma noradrenaline observed may reflect a widespread diminution of sympatho-adrenal activity during water immersion. This reduction could be a consequence of the cardiovascular changes of immersion and may not be directly involved in the mechanism of the renal response.  相似文献   
5.
C3H fibroblasts transformed in vitro with SV40 were adapted to in vivo growth. Several clones were isolated from a single, highly oncogenic tumor and those that displayed oncogenic potential also no longer expressed the H-2Kk molecule. Using the technique of Southern blot hybridization, the H-2 genes and integrated SV40 sequences present in the genomic DNA of several of these clones have been examined and compared with both the parent line and normal liver genomic DNA from C3H mice. All H-2Kk negative clones had altered H-2 genes that appeared as a gain and, depending on the restriction endonuclease, loss of hybridizing fragments compared to normal C3H DNA. A 5.5-kb fragment missing from the Sstl digests of the H-2Kk negative variants was mapped to the H-2Kk region of the major histocompatability complex with the use of congenic mice. This provided direct evidence that a mutation had occurred in the H-2Kk region. The integrated SV40 sequences were similar to those already seen in other SV40 transformed cells and not closely linked to any of the H-2 genes. There was no indication that the H-2 mutation was caused by integration of SV40.  相似文献   
6.
The effects of the trichothecene mycotoxins (acetyl T-2 toxin, T-2 toxin, HT-2 toxin, palmityl T-2 toxin, diacetoxyscirpenol (DAS), deoxynivalenol (DON), and T-2 tetraol) on bovine platelet function were examined in homologous plasma stimulated with platelet activating factor (PAF). The mycotoxins inhibited platelet function with the following order of potency: acetyl T-2 toxin > palmityl T-2 toxin = DAS > HT-2 toxin = T-2 toxin. While T-2 tetraol was completely ineffective as an inhibitor, DON exhibited minimal inhibitory activity at concentrations above 10×10?4M. The stability of the platelet aggregates formed was significantly reduced in all mycotoxin treated platelets compared to that of the untreated PAF controls. It is suggested that the increased sensitivity of PAF stimulated bovine platelets to the more lipophilic mycotoxins may be related to their more efficient partitioning into the platelet membrane compared to the more hydrophilic compounds.  相似文献   
7.
During the period of COVID-19, the occurrences of mucormycosis in immunocompromised patients have increased significantly. Mucormycosis (black fungus) is a rare and rapidly progressing fungal infection associated with high mortality and morbidity in India as well as globally. The causative agents for this infection are collectively called mucoromycetes which are the members of the order Mucorales. The diagnosis of the infection needs to be performed as soon as the occurrence of clinical symptoms which differs with types of Mucorales infection. Imaging techniques magnetic resonance imaging or computed tomography scan, culture testing, and microscopy are the approaches for the diagnosis. After the diagnosis of the infection is confirmed, rapid action is needed for the treatment in the form of antifungal therapy or surgery depending upon the severity of the infection. Delaying in treatment declines the chances of survival. In antifungal therapy, there are two approaches first-line therapy (monotherapy) and combination therapy. Amphotericin B ( 1 ) and isavuconazole ( 2 ) are the drugs of choice for first-line therapy in the treatment of mucormycosis. Salvage therapy with posaconazole ( 3 ) and deferasirox ( 4 ) is another approach for patients who are not responsible for any other therapy. Adjunctive therapy is also used in the treatment of mucormycosis along with first-line therapy, which involves hyperbaric oxygen and cytokine therapy. There are some drugs like VT-1161 ( 5 ) and APX001A ( 6 ), Colistin, SCH 42427, and PC1244 that are under clinical trials. Despite all these approaches, none can be 100% successful in giving results. Therefore, new medications with favorable or little side effects are required for the treatment of mucormycosis.  相似文献   
8.
Cell-mediated immunity to SV40-transformed C3H and C3H-SW cell lines was measured by using both 51Cr and 125IUdR release assays. Killing by cytotoxic cells generated on in vitro sensitization of immune spleen cells with syngeneic SV40 cells by either assay is specific for syngeneic SV40 transformants. Cytolysis mediated by in vitro sensitized cells is ablated by treatment of the effector cells with anti-theta serum and complement. Intraperitoneal immunization with syngeneic SV40 cells yields two distinct killer-cell populations in the peritoneal exudate when assayed by 125IUdR release. The first, nylon wool nonadherent and sensitive to anti-theta and complement, is indistinguishable from the killers generated in vitro. The second population, present in larger numbers and more efficient on a per-cell basis in killing of SV40 targets than the first, is nylon adherent and is not removed by treatment with anti-theta and complement. This second population will kill any SV40 transformed target, whether syngeneic or allogeneic. The possible roles of T cell and non-T cell effectors in rejection of syngeneic SV40 tumors are discussed.  相似文献   
9.
Optical. e.p.r. and near-infrared low-temperature m.c.d. (magnetic-circular-dichroism) spectroscopy were used to characterize the partially reduced cyanide-inhibited derivative of cytochrome c oxidase produced by anaerobic reductive titration with dithionite. The reductions of cytochrome a3+ and Cu2+a were followed by observation of the e.p.r. signals at g = 3.03, 2.21 and 1.5 and at g = 2.18, 2.03 and 1.99. As reduction proceeds new e.p.r. signals (g = 3.58 and 1.56) appear that quantify to give one haem per enzyme unit when a small excess of dithionite has been titrated in. The e.p.r. signal of the Cu2+a titrates in parallel with the disappearance of the band and 820nm in the optical absorption spectrum. The near-infrared m.c.d. spectrum shows the presence of the low-spin ferric haem, a3+, in the oxidized state of the enzyme, as a well-resolved positive peak at 1650nm. As reduction proceeds this band is replaced by one at 1550nm due to haem a3+(3)--CN in the partially reduced state. Hence as haem a3+(3)--CN becomes e.p.r.-detectable it also shows a near-infrared m.c.d. spectrum characteristic of a low-spin ferric haem. It is concluded that the partially reduced state of cyanide-inhibited cytochrome c oxidase contains a2+ . Cu+a . a3+(3)--CN . Cu+a3.  相似文献   
10.
The use of a fascial flap in ear reconstruction.   总被引:2,自引:0,他引:2  
We describe the use of a fascial flap for covering the framework in ear reconstruction. When covered in turn with a skin graft, this fascial flap provides an abundant amount of a thin, tough, vascular, hairless cover of good quality in all cases except those where injuries in the auricular area have been deep enough to damage this fascia. This method of ear reconstruction is particularly useful in secondary ear reconstructions useful in secondary ear reconstructions and in reconstruction after traumatic losses. The procedure described can often be performed in one stage, requiring two to 4 hours, with minimal complications.  相似文献   
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