Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mammalian spermatozoa have been dissected by a variety of chemical techniques to yield free heads, tails with attached midpieces, and tails without mitochondria. By brief exposure to trypsin, mouse and rat spermatozoa were cleaved at the junction of the head and the tail, while human, guinea pig and rabbit spermatozoa were cleaved by trypsin only after prior incubation with a sulphhydryl reducing agent. Treatment with acid or base cleaved spermatozoa of all species examined. In contrast, exposure of spermatozoa to 1% sarkosyl NL-97 resulted in the quantitative cleavage of mouse cells without noticeable effect on the spermatozoa of the other species. Mitochondria were removed from the midpiece of intact sperm and isolated tails by gentle shaking after treatment with reducing agents. Homogeneous populations of spermatozoan subcellular components were obtained by density gradient centrifugation. Ultrastructural analysis showed that cleavage of mouse spermatozoa by trypsin occurs at a specific location in the neck of the cell without trypsin occurs at a specific location in the neck of the cell without observable damage to other cell structures. The basal plate remained attached to the head structures. In contrast cleavage of spermatozoa by sarkosyl or acid left the basal plate attached to the spermatozoan midpiece. Sarkosyl also removed the plasma membrane and extracted mitochondrial components. Treatment with acid or base also resulted in vesiculation of the plasma membrane and dissolution of the acrosome. Molecular probes have also been used to facilitate mapping of the cell surface. Each mouse spermatozoon has about 10-7 receptors for the lectin concanavalin A. Binding of fluorescein-labelled concanavalin A indicated that the majority of the receptors is in the acrosomal region; this polar distribution was confirmed by measurement of the number of sites on purified heads and tails. In addition, the low molecular weight probe ANS bound to the plasma membrane of spermatozoa from all species examined, with immediate immobilization of the cells. Ethidium bromide bound to the spermatozoan head without affecting motility.
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PMID:Chemical dissection of mammalian spermatozoa. 23 23

DDT was administered to the guinea pig, mouse and rat either ig or ip and to the hamster ig in order to investigate variations in the response of hepatic and duodenal drug-metabolizing enzymes to DDT. The intragastric dose (160 mg/kg) was found to produce gastric bleeding and severe tremor in rats and mice but not in other rodents. The hepatic aryl hydrocarbon hydroxylase activity and cytochrome P-450 concentration decreased after the ig administration of DDT to rats, mice and guinea pigs but in hamsters the activiy of aryl hydrocarbon hydroxylase and cytochrome P-450 concentration increased 12 hr after the dosage. The aryl hydrocarbon hydroxylase activity decreased also in the duodenal mucosa of the rat after the ig administration of DDT. The ip dose had no effects on the hepatic or duodenal monooxygenase system in 12 hr. The UDPglucuronosyltransferase activity was slightly lowered in hepatic microsomes of the rat and mouse after the ig dose of DDT, but the decrease was more profound when measured after in vitro trypsin digestion of microsomes. The trypsin digestion activated the hepatic UDPglucuronosyltransferase in all the species studied, i.e., guinea pig, hamster, mouse and rat (3-, 3-, 5-, and 8-fold, respectively). The duodenal UDPglucuronosyltransferase activity was not affected by DDT administration in any of the species studied. The results suggest that the acute toxic effects of DDT are species-dependent and the administration route is important in DDT toxicity. The hydroxylation step in drug metabolism is more sensitive to DDT than the glucuronidation step.
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PMID:Effect of administration route on DDT on acute toxicity and on drug biotransformation in various rodents. 81 74

Solid phase peptide synthesis and air oxidation of omega-conotoxin GVIA yielded, in addition to the desired product, an isomeric peptide which could be completely separated from the native toxin by repeated HPLC. A chymotrypsin-trypsin digest of this peptide, when subjected to HPLC peptide mapping, provided peptides identical with synthetic disulfide containing peptides predicted for the omega-conotoxin isomer containing C1-C2, C3-C5, C4-C6 cystinyl pairings. The 'shaking' potency (ED50 = 1500 pmoles/kg, i.c.v.) of the isomeric peptide upon cannulated rats was 1.3% of the potency of native conotoxin (ED50 = 20 pmoles/kg). Considering that all three disulfide pairings in the isomer are different from the native toxin, its retention of biological activity is of interest.
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PMID:Synthesis and characterization of a disulfide bond isomer of omega-conotoxin GVIA. 150 93

To study the development of acute pancreatitis after intraductal trypsin instillation, at 4 hours, 1, 2, 4 and 6 days after this treatment and after instillation of physiologic saline viable acinar cells were isolated from rat pancreas. Gross anatomic and histologic findings were used to evaluate the time course of pathomorphologic changes. The isolated cells were incubated at 37 degrees C in Eagle's medium in a shaking water bath and the time course of their damage was studied. Additionally, by means of the active accumulation of the fluorophore rhodamine 6 G alterations of the mitochondrial membrane potential, an important parameter of the cellular energy metabolism was evaluated. The most severe histological damage was seen 1 and 2 days after trypsin instillation. At the same time yield and survivability of cells isolated, and their mitochondrial membrane potential reached a minimum. In the controls the time course of these parameters was very similar, but their decrease was less pronounced. Since a direct action of trypsin on acinar cells cannot be responsible for the findings presented a possible involvement of inflammatory cells and their products in the alteration of the cells and of their energy metabolism must be considered.
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PMID:Influence of trypsin-induced acute pancreatitis on survival and energy state of isolated acinar cells from rat pancreas. 159 92

The antiviral activity of three types of spotted souslik interferons So IFN alpha, So IFN beta and So IFN gamma was studied. Fibroblasts of lungs (SL), kidneys (SK) of adult sousliks and skin fibroblasts of foetuses (SE) were equally sensitive to three types of souslik interferons. In contrast to So IFN beta and So IFN gamma, So IFN alpha, exhibited a high (100% of activity in homologous cells) cross species antiviral activity in mouse embryo fibroblasts (MEF) and a low (3% to 10% of the activity) in bovine embryo fibroblasts (BEF) and human embryo fibroblasts (HEF). The development kinetics of antiviral activity not only depended on the interferon type but also on the temperature of incubation. In comparison with So IFN gamma, So IFN alpha and So IFN beta activated earlier the maximal antiviral state. Low incubation temperature (26 degrees C) did not decrease but only delayed the antiviral activity of spotted souslik interferons. Mixed preparations of So IFN gamma with So IFN alpha or So IFN beta exhibited synergistic antiviral activity at physiological (37 degrees C) and low (26 degrees C) temperatures. The development of antiviral activity of So IFN beta as well that of Mu IFN alpha/beta was inhibited by plant lectins which reacted with the cell membrane compounds. All three types of souslik interferons were completely destroyed by trypsin and boiling at 100 degrees C for 1 min. and partially by SDS. Their sensitivity to shaking, beta-mercaptoethanol and mouse antisera against So IFN beta was different in relation to the interferon type.
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PMID:Characterization of antiviral activity of spotted souslik (Spermophilus suslicus) interferons. 244 74

A trypsinization technique was optimized for preparation of human epidermal single-cell suspensions from suction blisters. The conditions which provided the highest epidermal cell yield and viability was Sigma trypsin 0.25% (Type II, crude; cat. no. T8128). The incubation time should be 45 min at 37 degrees C with continuous shaking of the epidermal tissue. The use of suction blisters was evaluated for in vivo determination of epidermal thymocyte activating factor (ETAF/Il-1). Trypsinization of epidermis diminished ETAF/Il-1 activity. Dialysis of epidermal homogenates improves determination of ETAF/Il-1-like activity due to removal of low-weight inhibitors. Determination of ETAF/Il-1-like activity in homogenates of suction blisters constitutes a reliable model with acceptable reproducibility.
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PMID:Preparation of human epidermal tissue for functional immune studies. 246 84

The characteristics of the steroidogenic response of reaggregated rat interstitial cells were examined in a perifusion system. Interstitial cells were isolated from 19-day-old rat testes by digestion with collagenase. The cells were cultured for 3 days as monolayers and were resuspended by brief treatment with trypsin. Constant gyratory shaking of the dispersed cells resulted in the formation of round and compact aggregates of 70-140 microns. The functional characteristics of these aggregates were examined by studying the output of cAMP, C19 steroids (testosterone and androstenedione), and C21 steroids (progesterone, 17 alpha-hydroxyprogesterone, 20 alpha-hydroxypregn-4-en-3-one) in a perfusion system. It is demonstrated that reaggregated interstitial cells maintain their responsiveness to LH, LHRH, and Leydig cell stimulatory factor(s) produced by Sertoli cells for at least 12 days. When exposed to low concentrations of LH (1 ng/ml), either in a continuous or in a pulsatile fashion, perifused aggregates maintain a constant output of steroids for more than 20 h. Under these conditions, LH-dependent differentiation of the steroidogenic machinery can be observed in vitro. In fact, although the sum of the measured steroids remains constant, C21 steroids progressively decrease whereas C19 steroid output increases during perifusion. When perifused with high concentrations of LH (10 ng/ml), desensitization becomes the predominant phenomenon. It is demonstrated that the steroid output of reaggregated interstitial cells considerably exceeds that of similarly treated cells maintained as monolayers. Moreover, perifusion of aggregates results in a 6-fold increase in steroid output as compared to static incubation and in a selective increase in androgen output. It is concluded that prepubertal interstitial cells allowed to reaggregate in suspension culture form functional multicellular structures. Perifusion of these aggregates is a useful tool in the study of the dynamics of the regulation of steroidogenesis.
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PMID:The dynamics of steroid and adenosine 3',5'-cyclic monophosphate output in perifused interstitial cell aggregates derived from prepubertal rat testes. 301 35

The synthesis of phospholipids and glycolipids during the cell mitotic cycle of an established hamster line, NIL, has been studied. Cells were synchronized with excess thymidine and mitotically harvested by shaking. Cells were radioactively labeled for 4 h with palmitate, glucosamine, or galactose. Lipids were analyzed by thin-layer chromatography. As cells progressed through the mitotic cycle, incorporation into phospholipids increased but the fraction represented by each remained constant. Similarly, ceramide monohexoside, dihexoside, and hematoside were labeled equally in all phases. Ceramide trihexoside and tetrahexoside were labeled only during G(1) and S. Ceramide pentahexoside (the Forssman antigen) shows density-dependent synthesis, accumulation, and reactivity. Ceramide pentahexoside was labeled during all phases of the mitotic cycle but the rate of incorporation decreased in S and G(2). The total amount of lipid assayed immunologically in cell extracts gradually increased. Exposure of the Forssman antigen in untreated or trypsin-treated cells was studied using binding of chemically labeled antiForssman antiserum. The amount of antigen detected in trypsinized cells increased during G(1) and early S but then remained constant. Mitotic cells exposed all detectable antigen. As cells progressed through the mitotic cycle, a large fraction of the Forssman antigen became cryptic.
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PMID:Cell mitotic cycle synthesis of NIL hamster glycolipids including the Forssman antigen. 483 89

The number of T. annulata sporozoites invading bovine peripheral blood lymphocytes (PBL) under different conditions (in vitro) was determined. Heat-inactivation of T. annulata sporozoites for 45 min, in a thermostatically controlled, shaking water bath preset and stabilised at 60 degrees C resulted in an almost total lack of invasion of fresh, normal PBL by the sporozoites, indicating that the interiorization process is parasite-effected. The mean number of T. annulata sporozoites interiorization (per 1000 lymphocytes) in cultures set up using sporozoites and PBL, mixed and incubated at 0 degrees C for 1 h in melting ice, was highly significantly reduced (P less than 0.01), indicating the invasion of bovine lymphocytes by T. annulata sporozoites is an active process dependent on active metabolism which is markedly affected by temperature. Pre-treatment of PBL with trypsin significantly reduced the number of invading sporozoites thus incriminating proteins or glycoproteins as constituents of receptors involved in sporozoite-lymphocyte recognition.
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PMID:Factors affecting the capacity of Theileria annulata sporozoites to invade bovine peripheral blood lymphocytes. 644 Mar 49

Monoclonal antibodies specific for cell surface antigens on embryonic chick ciliary ganglion neurons (CG) have been obtained at high frequencies by fractionating spleen cells from immunized mice according to their adhesiveness for cell surfaces of the cultured neurons. Spleen cells from mice that had been immunized with live or lightly fixed (0.125% glutaraldehyde) CG neurons were selected for subsequent hybridization with myeloma cells after fractionation on lawns of CG neurons in tissue culture. Immunized spleen cells were cultured with the neurons for 4-7 days prior to fractionation. Three groups of spleen cells were selected for fusion with a myeloma cell line: a non-adherent population of spleen cells, a population of spleen cells that could be removed from the neuronal cells by shaking on a vibratory shaker for 1 h, and a population that could be removed from the neuronal cells only by treatment with low concentrations of trypsin. Of the 3 groups of spleen cells, the population that required trypsin treatment produced the greatest number of hybridomas specific for neurons and for neuronal cell surfaces. Fewer neuron-specific hybridomas resulted from fusion of the group of spleen cells that could be removed from the antigen lawn by shaking. None of these was specific for the CG neurons. No neuron-specific hybridomas resulted from the fusion of the cells that did not adhere to the neuronal cells, and at most only 1 neuron-specific hybridoma resulted from fusions of comparable groups of unselected spleen cells (spleen cells from immunized animals which were not selected on antigen lawns).
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PMID:Differential antigen adhesivity used to select spleen cells for the production of monoclonal antibodies to embryonic neurons. 649 Dec 93


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