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61.
Menstrual synchrony in human females has previously been demonstrated among women attending a predominantly female university as well as among women attending coeducational universities. In each of these studies, women who spent the most time together were most likely to show the menstrual synchrony. In this experiment, the possibility that substances in axillary secretions might mediate this effect was tested using a prospective, double-blind research design and a combined axillary extract from a group of female donors. Female subjects who reported themselves to have normal (29.5 +/- 3 day) cycles were exposed to the axillary extracts or blank/ethanol for 10 to 13 weeks. Recipients of the axillary extracts showed a significant reduction in "days' difference in menses onset" relative to the donor cycle, no change was evident for recipients of blank/ethanol. These results demonstrate that constituents from the axillary region of donor females can shift the time of menstrual onset of another group to conform with the donors' cycle and that this effect can occur even in the absence of social contact.  相似文献   
62.
Dansyl derivatives of epsilon-N-mono-, epsilon-N-di-, and epsilon-N-trimethyllysine were resolved from other amino acids in proteins by the use of high-performance liquid chromatography. The system was tested with amino acid standard combinations as well as with acid-hydrolyzed proteins known to contain methylated residues. In all cases the methylated lysines were well resolved.  相似文献   
63.
The biological activities of ANF (Arg 101-Tyr 126) and of the circulating form, ANF (Ser 99-Tyr 126), were compared in the following assays: precontracted rabbit aortic strip and chick rectum, rat natriuresis, inhibition of aldosterone secretion and receptor affinity in bovine and rat adrenal zona glomerulosa cells, and receptor affinity in rabbit aorta and rat mesenteric artery cells. The results demonstrate that both peptides share the same biological activities. It is concluded that the addition of two amino acids to the N-terminal of ANF (Arg 101-Tyr 126) does not modify its biological characteristics, validating thus previous research employing this peptide.  相似文献   
64.
A magnesium-dependent protein kinase activity was copurified with both the molybdate-stabilized 8S form of the chick oviduct progesterone receptor (PR) and its B subunit. In each case, purification was performed by hormonal affinity chromatography followed by ion-exchange chromatography. The Km(app) values of the phosphorylation reaction for [gamma-32P]ATP and calf thymus histones were approximately 1.3 X 10(-5) M and approximately 1.6 X 10(-5) M, respectively, and only phosphorylated serine residues were found in protein substrates, including PR B subunit. Physicochemical parameters of the enzyme [pI approximately 5.3, Stokes radius approximately 7.2 nm, sedimentation coefficient (S20,w) approximately 5.6 S, and Mr approximately 200,000] were compared to those of purified forms of PR (B subunit, pI approximately 5.3, Stokes radius approximately 6.1 nm, and Mr approximately 110,000; 8S form, Stokes radius approximately 7.7 nm and Mr approximately 240,000). The results suggest that most of the protein kinase activity copurified with both oligomeric and monomeric forms of PR belongs to an enzyme distinct from currently known receptor components. Its physiological significance remains unknown.  相似文献   
65.
Specific receptors for atrial natriuretic factor (ANF) have been identified and solubilized in glomeruli from rat kidney. Radioiodinated synthetic ANF (Arg 101-Tyr 126) bound to a single class of high affinity (Kd 27 +/- 24 pM) sites with a density of 390 +/- 230 fmole/mg protein. The binding was time- and temperature-dependent, saturable and reversible. The ANF-receptor complex was not affected by angiotensin II, ACTH or vasopressin. Solubilization with 10 mM 3-[(3-cholamidopropyl)-dimethylammonio]- 1-propane sulfonate (CHAPS) slightly increased the affinity for ANF (Kd 5.0 +/- 3.3 pM) without affecting the density (250 +/- 110 fmole/mg protein). Similar results were found with 1% Triton X-100. ANF-related peptides interact generally in the same way with non-solubilized and solubilized receptors, indicating a fully preserved specificity of the receptors.  相似文献   
66.
An atrial natriuretic peptide has been isolated from plasma of morphine treated rats by means of glass beads extraction, immunoaffinity chromatography, and reverse phase HPLC. 1.3 micrograms of immunoreactive material was obtained. The biological activity of this material was found comparable to that of ANF (Arg 101 - Tyr 126) on the inhibition of basal aldosterone secretion by rat adrenal zona glomerulosa cells and the displacement curve of iodinated ANF from ANF receptors in a mesenteric artery preparation. Gas phase amino acid sequencing indicated that it is related to ANF (Ser 99 - Tyr 126). These results suggest that the maturation of ANF may require a tryptic-like cleavage after a single Arg residue.  相似文献   
67.
Monomolecular films of lecithin, gangliosides or lecithin/gangliosides mixtures were studied on a Langmuir through in order to examine the interactions between these lipids and opioid agonists or antagonists. Lecithin alone did not interact in a monolayer structure with opioids. However, gangliosides and lecithin/gangliosides mixtures were expanded by both morphine and naloxone. The expansion of ganglioside-containing monolayers was greater with morphine than with the antagonist, naloxone.  相似文献   
68.
We have studied the effect of insulin hypoglycemia on the secretion of pancreatic polypeptide (PP) in 14 obese subjects with normal glucose tolerance and in 6 normal controls. Infusion of insulin 0.1 U/kg/h in controls and 0.12 U/kg/h in the obese, for one hour, produced a progressive hypoglycemia, similar in both groups (nadir 2 mmol/l at 50 min). The secretion of PP was less in obese subjects than in controls (peak 116 mmol/l vs 184 pmol/l, P less than 0.01) (integrated secretion sigma delta PP 288 vs 472 pmol/l, P less than 0.01) and was also delayed in the obese subjects beginning at 50 min instead of 40 min. The secretion of glucagon and of C-peptide were not different in the two groups, but the integrated response of ACTH was higher in the obese (sigma delta ACTH 52 pmol/l vs 25 pmol/l, P less than 0.01). The secretory response of growth hormone (STH) was smaller in the obese group (peak 8.6 +/- 1.28 vs 21.4 +/- 6.4 ng/ml, P less than 0.01). The reduced secretion of PP in obese subjects could be due to impaired sensitivity to hypoglycemia of the central control mechanism for PP release. The similarity of the reductions in the secretion of both PP and STH support this hypothesis, although a reduction in the secretory capacity of pancreatic PP cells cannot be excluded.  相似文献   
69.
An experimental Keratitis study of Aspergillus fumigatus was performed in 130 rabbits divided into 12 groups of ten animals each. Three antifungal drugs (myconazole, amphotericin B and pimaricin) were tested using two procedures (topical drops and subconjunctival injections) and two different concentrations (500 and 10 000 times the MIC). In each case, the drugs were applied every 3 h starting 14 h after inoculation. Miconazole was useful at 10 mg/ ml concentration by topical drops and subconjunctival injections, but was less useful at 5 mg/ ml. Amphotericin B was useful at 5 mg/ ml concentration by topical drops and less useful at 2 mg/ ml.No differences were found between the two concentrations by subconjunctival administration. Pimaricin was useful by topical drops at 50 mg/ ml concentration and less useful at 10 mg/ ml as well as by subconjunctival injections.  相似文献   
70.
Ivermectin (0.2 mg/kg body weight) caused a high mortality in nymphs and adults of Rhodnius prolixus following a single meal in mice sub-cutaneously injected with the drug. This effect was more evident in nymphs of 1st-and 2nd-instar than in older nymphs and adults. Third-instar nymphs presented a high mortality when fed on mice treated with ivermectin 24 and 48 hours previously, while mortality was significantly reduced in nymphs fed on mice treated 72 hours before. Surviving 3rd-instar nymphs did not molt. When adult females were fed once on mice treated for 24 hours with ivermectin there was a considerable reduction in egg production. This inhibition was not reversed by a second feeding on normal mice. We concluded that sub-lethal doses of ivermectin caused toxic effects interfering in the neuro-endocrine control of development and reproduction of this bloodsucking insect.  相似文献   
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