Epithelial cell proliferation and migration in the developing rat gastric mucosa

To investigate cell proliferation in developing gastric antrum and fundus, proliferating gastric epithelial cells were labeled in fetal rats by intravenously injecting mothers with [³H]thymidine. In addition 14-day postnatal (dPN) rats were given [³H]thymidine intraperitoneally. Tissue was removed 1.5 hr later, and autoradiographs were prepared to identify proliferating cells. Total epithelial labeling indices (L.I.) reached a peak at 20 days gestation (dG), coincident with the appearance of pit/glands, then declined again by 22 dG (gestation end). At 18 dG, labeled cells were distributed throughout all levels of the stratified epithelia. Between 20 and 22 dG, as pit/gland development proceeded, labeled cells became concentrated in the gland bases and were only rarely seen on the surface (L.I. of surface cells <1% at 22 dG). By 14 dPN, proliferating cells were entirely absent from the epithelial surface. Approximately 15% of the endocrine cells were labeled at 22 dG, compared to only 2% at 14 dPN; zymogen cells were labeled (～6%) at 14 dPN; parietal cells did not label at any age studied. In addition, cell migration to the epithelial surface was studied in rats labeled at 22 dG, 14 dPN, or 28 dPN, and killed 1–20 days later. Migration times were slightly shorter in the 28 dPN group and were longer in fundus than antrum in all groups.     

Stimulation of gastrin secretion from the perfused rat stomach by somatostatin antiserum

The effect of a high capacity somatostatin antiserum on antral gastrin secretion was examined in an isolated vascularly perfused rat stomach preparation. Infusion of somatostatin antiserum diluted 1:1 and 1:9 with Krebs buffer solution produced significant increases in gastrin secretion throughout the period of infusion. Neither infusion of somatostatin antiserum diluted 1:99 nor infusion of control rabbit serum had any effect on gastrin secretion. The data indicate that antral somatostatin excercises a continous restraint on gastrin secretion in the basal state.     

Clinical response of patients with galactorrhea to pergolide,a potent,long-acting dopaminergic ergot derivative

Pergolide is an ergot derivative with dopaminergic activity and, like bromocriptine, can suppress prolactin release from the pituitary gland. In a single blind study pergolide was administered for 90 days to three females with idiopathic hyperprolactinemia manifested by galactorrhea and amenorrhea. Response to therapy was followed clinically and by determination of plasma prolactin concentrations. Pergolide lowered plasma prolactin concentrations and suppressed galactorrhea in all patients. Menstruation recurred in both patients with intact GU systems. Side effects were minor and tolerance developed to all but nasal stuffiness. Pergolide appears to be efficacious therapy for patients with amenorrhea/galactorrhea secondary to hyperprolactinemia.     

Activation of lymphoid cells by BCG in vitro

Bacillus Calmette-Guerin (BCG) stimulated splenic and thymic lymphocytes in vitro as measured by uptake of ³H-thymidine. This activation of lymphocytes by BCG required the presence of a critical concentration of macrophages. Thymus cells containing no more than 0.25% macrophages were stimulated by BCG, but reduction of macrophages below this level by adherence to plastic abolished the response. Reconstitution with purified macrophages completely restored the response. A high concentration of adherent cells (“macrophages”) depressed the response of splenic lymphocytes, as judged by the improvement in DNA synthesis after reduction of the proportion of adherent cells in the spleen cell population.Bacillus Calmette-Guerin augmented the production of lymphocyte-activating factor (LAF) from purified splenic adherent cells, but the presence of lymphocytes made that augmentation considerably greater.These data reaffirm the bidirectional nature of the relationship between lymphocytes and macrophages. They further show that BCG can create highly activated populations of each type of cell, in part by enhancing their interaction.     

Reduction and Subsequent Binding of Ruthenium Ions Catalyzed by Subcellular Components

The reduction of Cl(NH₃)₅Ru(III) and subsequent binding of heterocyclic ligands by the resultant (H₂O)(NH₃)₅Ru(II) ion is shown to be catalyzed by components of rat-liver cells. The presence of air significantly decreases the rate of heterocyclic ligand binding. In the case of microsome and soluble component catalysis, this is probably due to oxidation of the Ru(II) ion prior to complexation. Various inhibitors of electron-transfer proteins were employed in an effort to determine the preferred reducing species. These results lend support to the hypothesis that the antitumor activity of acido ruthenium(III) ammine complexes involves activation by reduction in vivo prior to metal coordination to nucleic acids. Anticancer drugs functioning by this mechanism may be preferentially toxic to or may localize in hypoxic areas of tumors.     

Genetic evidence for the common identity of glucose-6-phosphatase,pyrophosphate-glucose phosphotransferase,carbamyl phosphate-glucose phosphotransferase and inorganic pyrophosphatase

We demonstrate that glucose-6-phosphatase, pyrophosphate-glucose phosphotransferase, carbamyl phosphate-glucose phosphotransferase and inorganic pyrophosphatase activities are deficient in livers of patients with type I glycogen storage disease. This provides strong genetic evidence that these enzymatic activities reside in a single protein or share a common polypeptide chain.     

14 C-acetate incorporation and nucleic acid synthesis in human lymphocytes stimulated by PHA and tuberculin in vitro

Studies on the timing of incorporation of labeled acetate in relationship to other cellular events in phytohemagglutinin (PHA)-treated lymphocytes have suggested that acetylation of nuclear histones may constitute an important regulatory mechanism for gene activation. In the present investigation, it was shown that PHA stimulation of lymphocytes from a tuberculin-positive patient caused an early increased incorporation of ¹⁴C-acetate prior to RNA and DNA synthesis. Lymphocytes from the same patient, however, repeatedly showed no increased incorporation of ¹⁴C-acetate following exposure to the sensitizing antigen, tuberculin (PPD), even though RNA and DNA synthesis were markedly stimulated. These results suggest that regulatory mechanisms of DNA template activity other than acetylation may be operative in sensitized lymphocytes responding to specific antigen. One possible explanation for the differences in ¹⁴C-acetate incorporation is that the increased uptake of acetate exhibited by PHA-treated cells is an effect related to nonspecific membrane changes caused by the PHA. If this is the case, then template regulation in PHA and antigen-stimulated lymphocytes may be achieved via similar but yet to be defined mechanisms.     

Zymosan activated plasma infusion in sheep: Effects of ethanol administration

Zymosan activated plasma infusion induces pulmonary sequestration of neutrophils and the release of TXA₂ into the pulmonary vascular bed causing profound and transient pulmonary hypertension.Since ethanol (ETOH) inhibits several inflammatory functions of neutrophils, including adherence and aggregation, we examined the ability of anesthetic doses of ETOH to alter the hemodynamic and cellular response to the infusion of zymosan activated plasma (ZAP) in vivo. Twenty five ml of autologous ZAP was intravenously infused into five control and seven (ETOH-treated sheep during mechanical ventillation. In control sheep the mean pulmonary artery pressure (PAP) transiently increased from 14.7±1.4 mm Hg (mean±SEM) to a pead of 38+8 mm Hg by three minutes after beginning the infusion of ZAP. Blood leukocyte concentration transiently decreased 19% below the baseline value due to pulmonary sequestration of polymorphonuclear leukocytes (PMN). Plasma TXB₂ levels measured by radioimmunoassay (RIA) increased from 0.2 to 5.4 ng/ml six minutes after the initiation of ZAP infusion.In five sheep, intravenous infusion of 200 ml of 96% ETOH yielded very high plasma concentrations (882±101 mg%) and completely inhibited both the rise of PAP and the increase of plasma TXB₂ levels after ZAP infusion. However, blood leukocytes transiently decreased 58% below the baseline value. Lower plasma levels of ETOH (200 and 400 mg%) did not prevent either the increase of PAP or the elevation of plasma TXB₂ after ZAP infusion.     

The subcellular distribution and partial characterization of cholinesterase activities of canine platelets

The multiple cholinesterase activities in canine platelets have been investigated. Platelets were homogenized by rapid decompression under nitrogen, glass tube/Teflon pestle, and glycerol lysis techniques. Rapid decompression under nitrogen technique was found to be the most efficient and gentle method for cell disruption. Homogenates were subfractionated using sodium diatrizoate density gradients. Marker enzyme assays and pulse labeling experiments with 5-hydroxy[¹⁴C]tryptamine and [¹²⁵I]thrombin on prepared subcellular fractions confirmed that the soluble, plasma membrane and the granule-1 fractions were all in reasonably pure form. Furthermore, labeling of the plasma membrane with [¹²⁵I]thrombin is cited as the first successful attempt at attaining a significantly bound marker for this structure. Cholinesterase activity distributions measured in these fractions indicated that about 30% of the activity was present in the plasma membrane, 50% in granule-1 and 5% in soluble fractions. Kinetic data of cholinesterase activities obtained from intact platelets, plasma membrane preparations and platelet release supernatants indicated that they are strikingly similar.     

Comparative evaluation of gastrointestinal blood loss in the feces of rats following pepto-bismol liquid and aspirin administration

Acetylsalicylic acid (aspirin) can irritate the gastrointestinal tract of man and of animals ultimately resulting in hemorrhagic erosions and ulcers. Since Pepto-Bismol liquid also contains salicylates (primarily bismuth subsalicylate), the relative sensitivity of the GI tract of the rat to hemorrhage and subsequent blood loss in response to Pepto-Bismol and to aspirin was determined. The appearance of blood in the feces of male Sprague-Dawley rats 22 hr after the peroral administration of aspirin or Pepto-Bismol at equivalent salicylate doses was measured spectrophotometrically using the modified benzidine assay. Aspirin, administered in total salicylate doses of 38.4, 57.5, 76.7 or 153 mg/kg caused a dose-dependent increase in blood loss ranging from 53 to 276 μl/kg body weight, the latter 2 values being significantly different from control. Pepto-Bismol at total salicylate doses of 38.4, 57.5 or 76.7 mg/kg failed to cause blood loss. Neither Pepto-Bismol nor aspirin obscured recovery of orally-dosed blood in rat feces. The sensitivity of the benzidine assay allowed for the quantitative assessment of 5 μl or less blood per gram of feces. It was concluded that at equivalent salicylate dose levels, Pepto-Bismol, unlike aspirin, did not cause a dose-dependent increase in blood in the feces of rats, suggesting that salicylates should not be collectively categorized as inducing gastric mucosal damage.     

Thromboxane and pulmonary hypertension following E. coli endotoxin infusion in sheep: Effect of an imidazole derivative

We assessed the effect of a specific thromboxane synthetase inhibitor (an imidazole derivative) on pulmonary hemodynamics and the concentrations of TxB₂ (TxA₂), 6-keto-PGF_1α (PGI₂), and PGF_2α in pulmonary lymph and transpulmonary blood samples following intravenous administration of E. coli endotoxin (1 μg/kg) in sheep. In control animals the rise in pulmonary artery pressure correlated with increases in plasma and lymph TxB₂ concentrations and large transpulmonary concentration gradients of this metabolite were measured. In imidazle treated animals both pulmonary hypertension as well as increases in plasma and lymph TxB₂ concentrations were substantially reduced. In contrast, peak concentrations of 6-keto-PGF_1α (PGI₂) and PGF_2α were severalfold higher than those measured in control animals. This suggests a shunting of endoperoxide metabolism towards prostacyclin and primary prostaglandins and documents the specificity of the thromboxane synthetase inhibitor. Out study provides evidence that endotoxin-induced pulmonary hypertension is mediated by pulmonary synthesis of TxA₂.     

Measurement of intratissue bioelectrical low frequency impedance: A new method to predict per-operatively the destructive effect of cryosurgery

A new cryosurgical technique is described, per-operatively using a device which measures the transtissue bioelectrical LF impedance. This technique enables the investigator to preselect and to freeze with precision the area to be cryodestroyed.     

Sedimentation velocity studies on microgram quantities of rat intestinal goblet cell mucin.

A procedure is outlined by which sedimentation analyses of small quantities of mucin glycoproteins can be performed. Rat intestinal goblet cell mucin was stained with periodic acid-Schiff reagent to permit detection by light absorption at 555 nm. PAS treatment resulted in chemical modification of sialic acid and 55% of fucose residues in the mucin. No other chemical or physical alterations were detected. The stained mucus was subjected to band ultracentrifugation using D₂O-containing solvents. Sedimentation was monitored by scanning at 555 nm. Results compared favorably with those reported earlier for conventional boundary ultracentrifugation of intact goblet cell mucin. Because of the low concentrations of mucin used in band ultracentrifugation (0.2–1.5 μg protein/ml), S_20,w values are comparable to sedimentation coefficients at zero concentration (S^o values), determined by conventional means.     

The in vivo metabolism of androgens by muscle and adipose tissue of normal men

Androstenedione and testosterone labeled with ³H and ¹⁴C were infused simultaneously at constant rates into the brachial arm vein of 10 normal men. During the infusions blood samples were obtained from the brachial artery, a deep vein draining primarily muscle and a superficial vein draining primarily adipose tissue of the arm contralateral to the infusion. In the 10 men the mean ± SE value for the fractional metabolism of androstenedione by muscle is 0.20 ± 0.30 which is not different from the mean value for the fractional metabolism of androstenedione by adipose tissue, 0.29 ± 0.04. The mean value for the metabolism of testosterone by muscle, 0.04 ± 0.01, is significantly less than the metabolism by adipose tissue, 0.11 ± 0.01. Intercpnversion between androstenedione and testosterone occurs in both tissues. The mean value for ρ^A,T_A,M is 0.024 ± 0.005 and for ρ^A,T_A,AT is 0.024 ± 0.005. The mean value for ρ^T,A_A,M is 0.005 ± 0.003 and for ρ^T,A_A,AT is 0.008 ± 0.003. The fractional metabolism of these androgens by these tissues is similar to the fractional metabolism of estrone and estradiol by these same tissues. Muscle appears to contribute about 5–12% of the overall metabolism of androstenedione and testosterone and 10–15% to the overall conversion of androstenedione to testosterone. Adipose tissue contributes about 2–7% of the overall metabolism of these androgens and 5–10% of the overall conversion of androstenedione to testosterone, but < 2% to the overall conversion of testosterone to androstenedione. In normal men, muscle appears to be more important to the metabolism of androstenedione and testosterone than is adipose tissue.     

Regulation of formation of covalently bound flavins in liver and cerebrum by thyroid hormones.

The effects of thyroxine (T₄) and triiodothyronine (T₃) treatment upon the formation of [2-¹⁴C]flavins bound covalently to tissue proteins in liver and cerebrum were measured 1 h after a subcutaneous injection of [2-¹⁴C]riboflavin in male rats of different ages. In livers of rats of ages 2, 3, and 12 months, T₄ (100 μg/100 g body wt) and T₃ (25 μg/100 g body wt) in daily intraperitoneal doses for 7 days each increased incorporation into covalently bound flavins 50% above that in saline-treated controls. In newborn rats, T₄ in doses of 10 μg/rat for 7 days increased incorporation similarly to that in adults. In adult rats doses of T₃ from 2.5 to 25 μg/100 g body wt were nearly as effective as larger doses of T₃ and T₄ in increasing the formation of covalently bound flavins in liver. In cerebra of newborn rats, T₄ was ineffective in increasing the formation of covalently bound flavins. However, in cerebra of rats of ages 2, 3, and 12 months, both T₃ and T₄ consistently increased the formation of covalently bound flavins. Doses of T₃ from 2.5 to 25 μg/100 g body wt produced significant increases. These findings are of interest in view of our previous demonstration that the formation of flavin adenine dinucleotide, the major tissue flavin, is not increased in rat brain even by massive doses of thyroid hormones. The present results indicate that the formation of the fraction of flavins bound covalently to tissue proteins differs from the usual pattern of brain metabolism of adult rats in being subject to control by thyroid hormones.     

Stimulation of ATP synthesis in hypothermically perfused dog kidneys by adenosine and PO4

During continuous hypothermic perfusion of dog kidneys there occurs a gradual decrease in ATP from about 1.4 to 0.6 μmol/g wet wt after 5 days of preservation. The loss of ATP can be prevented by including both adenosine (10 mM) and PO₄ (25 mM) in the perfusate. Under these conditions kidney cortex ATP levels were more than double control values — 3.5 μmol/g wet wt. Both adenosine and PO₄ were necessary since omission of one substance resulted in no net synthesis of ATP. Furthermore, these high levels of ATP were obtained only if adequate concentrations of adenosine were maintained during perfusion. Following 3 days of perfusion the adenosine level in the perfusate decreased to about 1 mM and under this condition ATP levels were low. Adenosine levels were maintained in the perfusate by two methods: (1) addition of fresh perfusate or (2) pretreatment of the kidney with the adenosine deaminase inhibitor—deoxycoformycin. The increased levels of ATP appear directly related to the availability of nucleotide precursors and the presence of inhibitors of the enzymes involved in the catabolism of nucleotides and nucleosides (PO₄ and deoxycoformycin). Mitochondrial activity was similar in kidneys with high or low ATP levels following 5 days of preservation.     

Neurological and electroencephalographic changes in newborns treated with prostaglandins E2 and E2

Six newborns with obstructive right heart lesions were examined neurologically and electroencephalographically during treatment with prostaglandin (PG) E₁ or E₂ given to maintain patency of the ductus arteriosus and to increase pulmonary blood flow. PG was administered intravenously or intraarterially in the aortic isthmus proximal to the ductus arteriosus. Besides a rise in arterial oxygen saturation, all patients had some sign of central nervous system involvement. The electroencephalogram showed minor changes suggestive of sedation. In addition, three patients in whom PG given intravenously presented various combinations of neurological abnormalities (“myoclonic jerks”, apnoeic spells, hiccup) of subcortical origin. Side-effects subsided after stopping the treatment anf posed no problem in the management of the patients. These findings confirm the usefulness and safety of the PG therapy and indicate that the intraaortic route of administration is preferable.