Agonist-independent, muscle-type-specific signal transduction pathways in cat esophageal and lower esophageal sphincter circular smooth muscle

Smooth muscle cells isolated from the circular muscle layer of cat esophagus and lower esophageal sphincter (LES) exhibit distinct contractile intracellular signal transduction pathways in response to acetylcholine. To determine whether these contractile pathways are muscle type dependent, the authors examined the signal transduction pathways utilized by substance P and bombesin, which in other tissues, use different signal transduction pathways, and by the GTP analog, guanosine 5'-O-3-thiotriphosphate (GTP gamma S), which activates all available G proteins. Western blot analysis of esophageal and LES circular muscle revealed the presence of Gq-G11 (42 kD), Gi1-Gi2 (40 kD) and Go-Gi3 (40 kD) types of G proteins. The responses of esophageal cells to bombesin and substance P were blocked by 1) a Gi3 protein antibody, 2) the inhibitor of specific phosphatidylcholine-phospholipase C (PLC) D609 potassium tricyclo-[5.2.1.0(2.6)]-decyl-(9[8])-xanthogenate, 3) inhibition of phosphatidic acid phosphohydrolase by propranolol, 4) the protein kinase C inhibitor 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H7) and 5) incubation in Ca(++)-free medium. Conversely, the responses of LES muscle cells to bombesin and substance P were blocked by 1) a Gq-G11 antibody, 2) a phosphatidylinositol-specific PLC antagonist U-73122 (1-[6-[[17 beta-3-methoxyestra-1,3,5(10)-trien-17- yl]amino]hexyl]-1H-pyrrole-2,5-dione), 3) the calmodulin inhibitor CGS9343B (1,3-Dihydro-1-[1-((4-methyl-4H,6H-pyrrolo[1,2-a]-[4,1]benzoxazepin++ +-4 - yl)methyl-4-piperindinyl]-2H-benzimidazol-2-one maleate) and 4) incubation in Sr++. After permeabilization by saponin, inositol 1,4,5-trisphosphate contracted LES but not esophageal cells. The inositol 1,4,5-trisphosphate receptor antagonist heparin and depletion of intracellular Ca++ stores by thapsigargin or A23187 4-Benzoxazolecarboxylic acid, 5-(methylamino)-2-[[3,9,11-trimethyl-8-[1-methyl-2-oxo-2-(1H-pyrrol- 2-yl)ethyl]-1,7-dioxaspiro[5.5]undec-2-yl]methyl]-, [6s-[6.alpha. (2S*,3S*),8.beta. (R*), 9.beta., 11. alpha.]]-(9Cl), blocked bombesin- and substance P-induced contraction of LES but not of esophageal muscle. In addition, contraction in response to GTP gamma S, which activates all G proteins, was blocked in esophageal cells by a Gi3-protein antibody, propranolol, D609 and H7. In LES muscle cells, the response to GTP gamma S was blocked by a Gq protein antibody, U-73122 and CGS934B. These data demonstrate that, in esophageal muscle, different agonists activate the same Gi3 protein, phosphatidylcholine-specific phospholipases and protein kinase C-dependent pathway.(ABSTRACT TRUNCATED AT 400 WORDS)

Kinetics and reversibility of thyrotropin-releasing hormone-stimulated guanine nucleotide exchange in membranes from GH4C1 cells

To evaluate the role of thyrotropin-releasing hormone (TRH)-stimulated guanine nucleotide exchange in the biphasic cellular responses to TRH, we have examined the kinetics, reversibility, and inhibition by QC120 (an antiserum recognizing the carboxyl terminus of alpha q/11) of TRH-stimulated guanosine-5'-(alpha-[35S] thio)triphosphate ([35S]GTP alpha S) binding in membranes from GH4C1 cells. Enhanced binding of [35S]GTP alpha S stimulated by TRH was dose dependent and readily detectable within 8 sec of TRH treatment. Binding measured within the first 20 sec was largely inhibited by QC120, whereas additional binding that accumulated during incubations of 3-6 min was not inhibited by even high concentrations of the antiserum. TRH-stimulated binding was reversible, in that, after membranes were incubated with TRH and [35S]GTP alpha S, subsequent addition of excess GTP caused exchange of 70-100% of the prebound radioligand. Exchange of TRH-stimulated [35S]GTP alpha S binding occurred in fast and slow phases, with half-times of < 5 sec and 187 sec, respectively. Addition of QC120 before the GTP chase inhibited the fast phase of exchange, whereas reduction of the TRH concentration in the preincubation selectively reduced the magnitude of the slow phase. Neither phase of exchange was affected by prior treatment of cells with pertussis toxin. Our observations indicate that Gq/11 is rapidly activated by the TRH receptor and that a second, unidentified, G protein is slowly activated by the TRH receptor.

Auditory startle in Swiss Webster mice fed excess aluminum in diet

Using an automated method, reduced auditory startle responsiveness was detected in Swiss Webster mice fed excess aluminum in diet (1000 micrograms Al/g) as compared to controls (7 micrograms Al/g). Excess aluminum diets were fed either from conception to weaning (developmental group) or from conception and continuing to 52 days of age (continuous group). At 22 days of age, lower response amplitudes were seen in the aluminum exposed groups than in controls. At 52 days of age, more rapid reduction in response amplitude across initial trial blocks was noted. Effects were more prominent in the continuously exposed than the developmentally exposed group at 52 days of age. Reduced auditory startle responsiveness is interpreted as part of a pattern of subtle motor impairment and marginally reduced activity and responsiveness in mice fed excess aluminum in diet.

Intramuscular selenium administration in selenium-deficient cattle

Nine recently weaned Hereford heifers were randomly assigned to a control group (n = 3) or a treatment group (n = 6). The animals were selenium (Se) deficient (mean +/- SD blood Se concentration = 0.024 +/- 0.012 microgram/mL). They were maintained on a selenium-deficient diet, and on day 0 of the study the treatment group was given 0.05 mg Se/kg body weight intramuscularly, while the control group received a placebo. The Se concentration of blood, serum, and urine as well as the glutathione peroxidase (GSH-Px) activity of blood and serum was measured over an 84-day period. Peak blood Se and serum Se concentrations (mean +/- SD) in the treatment group occurred at 5 hours postinjection and were 0.131 +/- 0.028 microgram/mL and 0.154 +/- 0.027 microgram/mL, respectively. The mean blood Se concentration of the treatment group was greater (P < .05) than that of the control group for the first 28 days after injection. The mean serum Se concentration of the treatment group was greater (P < .05) than that of the control group for all times after injection, except for day 56. The mean (+/- SD) blood GSH-Px activity of the treatment group (12.0 +/- 2.3 mU/min/mg hemoglobin) was increased (P < .05) over the control group (2.0 +/- 1.4 mU/min/mg hemoglobin) by day 28 and continued to be greater (P < .05) throughout the 84 day postinjection period.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum accumulation and neurotoxicity in Swiss-Webster mice after long-term dietary exposure to aluminum and citrate

The present study was performed to determine aluminum uptake, retention, and neurotoxic effects in the presence of dietary citrate. Six-week-old female Swiss-Webster mice were fed semipurified diets containing 3.5% sodium citrate and either 3 micrograms Al/g diet (3 Al) or 1,000 micrograms Al/g diet (1,000 Al) as AlCl3. After 5 to 7 weeks of feeding these diets, changes in behavior were assessed using the National Institute of Environmental Health Sciences Neurobehavioral Test Battery. Liver and bone Al concentrations in the 1,000 Al group were higher than in the 3 Al group at both the 5- and 7-week time points. Spinal cord Al concentrations in the 1,000 Al group were 200% higher at 5 weeks (P < .01) than in controls, and brain nuclear fraction Al concentrations in the 1,000 Al group were 150% higher at 5 and 7 weeks (P < .01) than in the 3 Al group. The Neurobehavioral Test Battery showed lower grip strength and greater startle responsiveness in the 1,000 Al group compared with the 3 Al group at both the 5- and 7-week time points. Based on reports that Al can act as a pro-oxidant, we examined Al-induced brain lipid and protein oxidative damage; neither was evident in the Al-intoxicated mice. In summary, feeding of Al and citrate to mice resulted in Al accumulation in the central nervous system, and this accumulation was associated with overt signs of neurotoxicity. Brain protein and lipid oxidative damage was not associated with early manifestation of Al toxicity.

Interferometric methods with enhanced sensitivity by optical/digital fringe multiplication

The equations of the optical/digital fringe multiplication method are derived for a general periodic distribution of intensity versus phase (or fringe order). The method is demonstrated by a shadow moiré experiment, which ideally produces fringe patterns with a triangular intensity distribution. Advantages and disadvantages of the optical/digital fringe multiplication method are discussed in comparison with other image-processing methods.

Developmental patterns of aluminum in mouse brain and effects of dietary aluminum excess on manganese deficiency

Previous studies have shown that excess dietary Al during development can affect neurobehavioral measures and decrease tissue Mn of 21-day-old weanling mice without a corresponding increase in tissue Al concentrations. Al and Mn have similar tissue concentrations and similar affinities for transferrin, which is the major plasma transport protein for Al and Mn as well as Fe. In the present study, brain Al, Mn and Fe were studied at 6, 12, 18 and 24 days of age in offspring of Swiss Webster mice fed a semipurified diet containing excess Al (Al[+], 1000 micrograms Al/g diet, Al as Al lactate), marginal Mn (Mn[-], 3 micrograms Mn/g diet) or both excess Al and marginal Mn (Al[+]Mn[-]) from conception to day 24 postnatal (weaning on day 18). Brain Al concentrations were higher at 6 days of age than at later ages and were significantly elevated by the excess Al diet (P = 0.017) but returned to control levels by weaning. Brain Mn concentrations increased from day 6 to day 24 and were lower in the Mn deficient groups (P < 0.001) and also in the excess Al group (P = 0.024) than in controls. Brain Fe concentrations were not influenced by diet. Similar patterns were seen in liver as in brain. The marginal Mn diet led to postnatal growth retardation which was more severe in litters of dams fed Al[+]Mn[-] diets than in litters fed Mn[-] diet. These data suggest that excess Al in diet can interact specifically with Mn metabolism during development.

Regional differences in retinoid release from embryonic neural tissue detected by an in vitro reporter assay

Retinoic acid and related retinoids have been suggested to contribute to the pattern of cell differentiation during vertebrate embryonic development. To identify cell groups that release morphogenetically active retinoids, we have developed a reporter assay that makes use of a retinoic acid inducible response element (RARE) to drive lacZ or luciferase reporter genes in stably transfected cell lines. This reporter gene assay allows detection of retinoids released from embryonic tissues over a range equivalent to that induced by femtomole amounts of retinoic acid. We have used this assay first to determine whether the floor plate, a cell group that has polarizing properties in neural tube and limb bud differentiation, is a local source of retinoids within the spinal cord. We have also examined whether the effects of exogenously administered retinoic acid on anteroposterior patterning of cells in the developing central nervous system correlate with differences in retinoid release from anterior and posterior neural tissue. We find that the release of morphogenetically active retinoids from the floor plate is only about 1.5-fold that of the dorsal spinal cord, which does not have neural tube or limb polarizing activity. These results suggest that the spatial distribution of retinoid release from spinal cord tissues differs from that of the neural and limb polarizing activity. This assay has also shown that retinoids are released from the embryonic spinal cord at much greater levels than from the forebrain. This result, together with previous observations that the development of forebrain structures is suppressed by low concentrations of retinoic acid, suggest that the normal development of forebrain structures is dependent on the maintenance of low concentrations of retinoids in anterior regions of the embryonic axis. This assay has also provided initial evidence that other embryonic tissues with polarizing properties in vivo release retinoids in vitro.

Effects of dietary aluminum excess and manganese deficiency on neurobehavioral endpoints in adult mice

Studies in mice have suggested that both dietary Al excess and dietary Mn deficiency promote oxidative tissue damage. To determine if these factors can interact to produce functional nervous system damage, female mice (N = 10-12 per group) were fed diets with control or low Mn (35 or 3 micrograms Mn/g diet) and/or control or high Al (25 or 1000 micrograms Al/g diet, Al as Al lactate) content for a 90-day period. No overt signs of neurotoxicity were observed in any group. Excess Al produced a threefold Al accumulation in both liver and brain, a slight acceleration of growth, decreased motor activity, decreased grip strength, and decreased startle responsiveness. Manganese deprivation led to liver, brain, and femur Mn depletion and reduced liver MnSOD activity but no neurobehavioral changes. No interactive effects between Al excess and Mn deficiency were observed. Neither Al excess nor Mn deficiency altered brain or liver lipid peroxidation measures. This study suggests that (1) subchronic dietary Al at doses of 1000 micrograms Al/g diet produces elevated brain Al and altered neurobehavioral indices in adult mice; (2) brain lipid peroxidation is not altered by this treatment; (3) dietary Mn deficiency does not influence Al neurotoxicity in adult mice.

[Alterations of Ulex europaeus agglutinin-1 receptor in human colorectal benign and malignant tumors]

The distributions and alterations of UEA-1 receptor in 116 human colorectal mucosa, included 20 normal mucosa, 16 inflammatory and 14 hyperplastic polyps, 34 adenomas, and 32 carcinomas, were studied with ABC technique. The results follow as: 1. There were positive staining of UEA-1 in proximal colon and negative in distal colon and rectum; 2. The frequency and intensity of UEA-1 receptor stained were increasing with the sequence of normal mucosa (7.7%), inflammatory polyps (25%), hyperplastic polyps (57.1%), adenomas (76.4%), and carcinomas (100%) in distal colon and rectum; 3. The staining pattern of UEA-1 in severe atypia adenomas was very similar to that in carcinomas and both of them were significantly difference from that in the other groups (P less than 0.05 or less than 0.01). The results suggested that UEA-1 receptor in distal colon and rectum may be considered as a probe studying course of malignant transformation and benefit to the diagnosis of carcinoma.

Radioimmunolocalization of human malignant tumors with In-111 labeled monoclonal antibody

An anti-human colon carcinoma monoclonal antibody 2C10 was radiolabeled with In-111 and studied in 15 patients with gastrointestinal and ovarian carcinoma. The labelling efficiency approached 100% and immunoactivity of the labeled antibody was over 75%. 2-3 mCi (1 mg) In-111-2C10 was given to the patients intravenously and scintigraphy was performed 72 hours after administration with a gamma camera. Specimens were also scanned in some of the patients. The resected tumors and remote margin were examined immunohistochemically. Positive scintigraphic images were obtained in 12/15 patients with colorectal cancer (10) and ovarian cancer (2). Negative results were seen in the two patients with gastric cancer. The scintigraphic results of 10 patients were confirmed surgically and pathologically. The remaining 5 were confirmed by endoscopy, B-ultrasonography or X-ray CT. Most patients had been definitely diagnosed before imaging except one patient with metastatic focus from ovarian cancer to colon and one with recurrent colon cancer were first detected with RIAD, showing the unique advantage the latfer. The high background radioactivity in the liver, however, is a conspicuous problem to be solved.

Influence of dietary-induced copper and manganese deficiency on ozone-induced changes in lung and liver antioxidant systems

The influence of an animal's copper (Cu) and manganese (Mn) status on its response to ozone was investigated in weanling mice. Control, Cu-deficient and Mn-deficient mice were exposed continuously to 1.2 ppm O3 or filtered air for 7 days. In control mice, ozone exposure resulted in higher lung activities of CuZnSOD, MnSOD and GPx. In contrast, Mn-deficient mice did not display increases in lung MnSOD, CuZnSOD or GPx activities following ozone exposure. Similarly, ozone-induced increases in lung CuZn-SOD and MnSOD activities were not observed in Cu-deficient mice, although lung GPx activity was increased in these mice relative to their air-breathing controls. These results show that an animal's Cu and Mn status can influence its response to ozone, and the data suggest that Cu- and Mn-deprived animals may be more susceptible to long-term or repetitive ozone exposure.

Cognitive impairment in musculoskeletal pain patients

To assess the incidence and relationship of cognitive/intellectual impairments to pain problems, seventy-three adults with musculoskeletal pain seen in a PM&R outpatient clinic were screened using the Neurobehavioral Cognitive Status Examination (NCSE). Subjective pain complaints were assessed using portions of the McGill Pain Questionnaire. Patients with prior diagnoses of neurocognitive problems or those who had taken narcotic analgesics in the last 24 hours were excluded. Results showed that 32 percent of subjects had impaired performance in at least one cognitive domain. Individuals with poorer performance on the NCSE had higher levels of reported pain or disability and psychological distress. Possible factors contributing to poor performance on cognitive tasks include psychological disorders or distress, undiagnosed organic brain dysfunction, social/psychological factors such as education, or a combination of these. Results suggest the need for further research to understand the relationship of poor performance on cognitive tasks to the etiology, maintenance and rehabilitation of pain problems.

Abdominoscrotal hydrocele--cause of abdominal mass in children

Abdominoscrotal hydrocele is relatively uncommon in adults and rare in children. The case presented typifies the classic features of the clinical presentation and the satisfactory response to conservative surgical therapy.