Progesterone and Oestrogen Concentrations in Plasma during Blastocyst Implantation in Mice Exposed to Triethyl Lead

Abstract: Female mice were injected intraperitoneally with triethyl lead chloride (3.0 or 6.0 mg/kg body weight, respectively) once a day on days 3–4 after mating. At the time of blastocyst implantation the plasma level of progesterone was significantly lower in females given 3.0 mg/kg body weight and the plasma levels of 17β-oestradiol and progesterone were significantly lower in females given 6.0 mg/kg body weight than in control females.     

A prospective epidemiological investigation of secretory otitis media and tubal dysfunction in children attending day-care centers. Serial tympanometry with an interval of two weeks

The present investigation included 373 children aged 9 months to 7 years, cared for in nine kindergartens and one nursery home. Serial tympanometries were carried out at 2-week intervals. A Madsen Electronics ZS 330 tympanoscope was used for the measurements. To identify A, C1, C2 and B tympanograms, middle ear pressure, compliance and stapedial reflex were measured. After correction for age and other factors which could influence the prevalence of B and C2 tympanograms (number of siblings and parental smoking, which was included in an investigation of the indoor environment of the same children), no significant difference was found in the prevalence of these types of tympanograms, even though the number of children attending the different day-care centers ranged from 19 to 72. No significant difference was found in the prevalence of the A, C1, C2 and B tympanograms between right and left ears, but there was a significant difference in the prevalence of the A tympanograms in boys and girls, but not in C1, C2 and B tympanograms. The maximum prevalence of B tympanograms was found in 1-year-old children, decreasing to the age of 7 years.     

HEAT DENATURATION OF HUMAN SERUM ALBUMIN. MIGRATION OF BOUND FATTY ACIDS

Prolonged heat treatment of solutions of human serum albumin at 60°C resulted in formation of one aggregate fraction and one fraction that was stable against further heat treatment. Fatty acid analyses on these fractions indicate that the heat stable fraction is formed by migration of fatty acids from the aggregating molecules to the remaining monomer thereby stabilizing the latter against heat denaturation. Disulphide and SH groups are involved in the aggregation process.     

Low levels of somatostatin in human CSF mark depressive episodes

Somatostatin-like immunoreactivity was measured in the cerebrospinal fluid (CSF) of 85 inpatients with current or recent episodes of major depressive disorders, diagnosed according to Research Diagnostic Criteria (RDC) as assessed with the Schedule for Affective Disorders and Schizophrenia (SADS). Several biopsychiatric tests were run during the same week of investigation. Results indicate low levels of CSF somatostatin to be a state marker for episodes of depression characterized by sad appearance, feelings of tiredness, insomnia, and subjective inability to acknowledge any external precipitants for the depression. CSF somatostatin was negatively related to platelet monoamine oxidase (MAO) activity; MAO activity appeared to account better for the degree of melancholic features than did somatostatin. The ratio between 3-methoxy-4-hydroxyphenylglycol (MHPG) and homovanillic acid (HVA) in CSF also correlated negatively with somatostatin. A positive relationship was noted between CSF xanthine and somatostatin. There was a highly significant curvilinear correlation between CSF somatostatin and serum TSH concentrations, but no correlations between CSF somatostatin and serum GH or prolactin, or with plasma cortisol before or after dexamethasone.     

The distribution of microsomal glutathione transferase among different organelles,different organs,and different organisms

1. In the present study we have used both enzyme assay with 1-chloro-2,4-dinitrobenzene as substrate and immunochemical quantitation to examine the distribution of microsomal glutathione transferase in different organelles, in different organs, and in different organisms.2. This enzyme was found to constitute 3% and 5%, respectively, of the total protein recovered in the microsomal and outer mitochondrial membrane fractions from rat liver, Microsomal glutathione transferase present in other subcellular fractions can be accounted for by contamination by the endoplasmic reticulum.3. In contrast to the situation with rat liver microsomes the glutathione transferase activities of microsomes from extrahepatic tissues of this same animal could not be activated by treatment with N-ethylmaleimide. Nonetheless, significant albeit low levels of a protein with the same molecular weight and immunochemical properties as the rat liver enzyme could be detected in microsomes from several extrahepatic tissues, notably the intestine, the adrenal, and the testis.4. Of those mammals for which fresh liver could be obtained, all demonstrated N-ethylmaleimide-activatable glutathione transferase activity in their liver microsomes. On the other hand, representatives for fish, birds, and amphibia did not demonstrate such activatable transferase activity in their liver microsomes. Toad was the only species that had a notable (twofold) sex difference in their level of hepatic microsomal glutathione transferase activity.     

Validation of Different Microdialysis Methods for the Determination of Unbound Steady-State Concentrations of Theophylline in Blood and Brain Tissue

Three microdialysis methods, the tritium method, the point-of-no-net-flux method, and a method using the low perfusion rate of 0.1 µl/min, were compared with respect to their ability to generate estimates of unbound steady-state concentrations (Cuss) of the antiasthmatic drug theophylline in blood and brain tissue in anesthetized rats. Concomitantly, the influence of the perfusion flow rate on the estimated extracellular Cuss obtained with the point-of-no-net-flux method was investigated. Theophylline was administered as a rapid intravenous bolus dose followed by constant intravenous infusion. Changes in perfusion flow rate from 2.0 to 0.75 µl/min and, finally, to 0.25 µl/min, using the point-of-no-net-flux method, had no significant effect on the estimated Cuss of theophylline in blood and striatum. This observation, particularly in the case of brain tissue, is not consistent with the theory that the process of dialysis drains a significant amount of substance from the immediate vicinity of the dialysis probe. Similar estimates of Cuss in blood as well as in brain tissue were obtained with all three methods. Their accuracy in estimating Cuss in blood was further strengthened by observations of unbound fractions similar to those reported in the literature. Furthermore, all three methods gave striatum/blood ratios at steady state of approximately 0.5, indicating that there is active transport of theophylline from brain tissue. It is concluded that the tritium method, when validated, can be used to study the time course of unbound drug concentrations in blood and tissues.     

Isolation of functionally active intraepithelial lymphocytes and enterocytes from human small and large intestine.

A mild purification method has been developed for the isolation of human intraepithelial lymphocytes (IEL) and enterocytes from the same individual. The isolation procedure includes mechanical disruption of the mucosal layer, treatment with reducing agent and sedimentation followed by Percoll gradient centrifugation. Finally, epithelial cells are removed from the IEL fraction using magnetic beads coated with the anti-epithelial antigen monoclonal antibody (mAb) BerEP4. Leucocytes are removed from the enterocyte fraction using magnetic beads coated with mAbs directed against common leucocyte antigen (CD45). Using this procedure IEL and enterocytes have been isolated from apparently normal jejunal, ileal and colonic tissue specimens. Recoveries of IEL were 7 x 10(5), 4 x 10(5) and 1 x 10(5)/cm2 mucosa from jejunum, ileum and colon respectively. 1-2 x 10(6) enterocytes/cm2 mucosa were recovered from small intestine while the corresponding value for colonic biopsies was approximately 2 x 10(5) enterocytes/cm2. The IEL fraction was pure as judged by the low percentages of B cells, macrophages and BerEP4 positive cells (less than 4%) present in the purified fraction. The enterocyte fraction contained less than 2% CD45+ cells. The two cell fractions were viable and expanded in vitro. Enterocytes expanded spontaneously while IEL required initial stimulation with mitogens. The isolation procedure described here will make it possible to study the function of human IEL, interactions between IEL and enterocytes and the role of both cell types in local immunity.