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Biomedical subjects

P Berry

Publications and source records attributed to P Berry.

13 recordsLinked to original sources
PubMed1992

Differences between jejunal myoelectric activity after a meal and during phase 2 of migrating motor complexes in healthy humans.

Using an intraluminal probe with six pairs of annular electrodes, the myoelectric activity of the proximal jejunum was recorded during 48-hr sessions in 16 healthy volunteers receiving evening and noon meals (1000 kcal) and breakfast (400 kcal). In 10 subjects receiving no drug, the characteristics of the migrating motor complexes (period, duration of each phase, velocity of propagation of phase 3, duration of the postprandial disruption) varied markedly between subjects but were relatively constant from the first to the second day of recording. Single spike bursts propagated at a rate of 2-5 cm/sec, clusters of 3-10 spike bursts propagated at a rate of 0.5-1 cm/sec, and similar clusters recurring repetitively each 1.5-2 min were observed after the meals and very rarely in the fasted state during phase 2 of nocturnal migrating motor complexes. In six subjects, oral administration of codeine (50 mg) 1 hr before a meal induced migrating motor complexes in the postprandial state, with characteristics similar to that observed in the fasted state except a longer duration of phase 2. Single spike bursts and isolated and repetitive clusters of spike bursts were observed during phase 2 of the codeine-induced migrating motor complexes and after meals preceded by placebo, but very rarely during the phase 2 of nocturnal (fasted state) migrating motor complexes. It is concluded that the patterns of jejunal contractions consisting of propagated single spike bursts and isolated or repetitive spike bursts characterize the postprandial state in healthy humans and are dependent upon digesta flow.

Adult↗
PubMed1992

Cholecystokinin and gastrin induce cell contraction in pig ileum by interacting with different receptor subtypes.

The aim of this study was to determine the cholecystokinin (CCK) receptor subtype involved in the direct myogenic effect of CCK on pig ileum. Smooth muscle cells were dispersed from pig ileum circular muscle layer and incubated in the presence of various concentrations of CCK agonists and antagonists. Contraction was assessed by measuring the length of 50 cells and expressed as the percentage decrease in cell length from control. Maximal contraction varied between 19% +/- 3% (gastrin II, 10 nmol/L) and 26% +/- 3% [CCK octapeptide (CCK-8), 10 nmol/L]. EC50 for CCK tetrapeptide (CCK-4) was the same than for pentagastrin (30 pmol/L), which were more potent than CCK-8 (100 pmol/L) and unsulfated gastrin 17 (100 pmol/L), which in turn were more potent than unsulfated CCK heptapeptide (CCK-7; 300 pmol/L) and sulfated gastrin II (300 pmol/L). The maximal contraction induced by synthetic analogs of CCK was 22% +/- 1% for 1 nmol/L JMV 170 and 23% +/- 1% for 10 nmol/L JMV 180. EC50 was 10 pmol/L for JMV 170 and 800 pmol/L for JMV 180. Contraction induced by 10 nmol/L CCK was inhibited as follows: L 365,260 half maximal inhibition (IC50) = 1 nmol/L greater than L 364,718 (IC50 = 90 nmol/L) greater than proglumide (IC50 = 1 mumol/L). Contraction induced by 10 nmol/L unsulfated gastrin 17 was inhibited as follows: L 365,260 (IC50 = 1 pmol/L) greater than L 364,718 (IC50 = 60 nmol/L) greater than proglumide (IC50 = 4 mumol/L). Removal of Ca2+ from the extracellular medium did not alter the contraction induced by CCK-8 (10 nmol/L) but impaired the contraction induced by unsulfated gastrin 17 (10 nmol/L) -56% in Ca(2+)-free medium, -77% in Ca(2+)-free medium plus 2 mmol/L EGTA, and -70% in the presence of 1 mumol/L nifedipine. These results show that the CCK receptor of pig ileum smooth muscle cells is closely similar to the B receptor and is not dependent on an influx of extracellular Ca2+ to induce cell contraction. By contrast, gastrin could act through a specific receptor subtype, the "gastrin receptor," triggering a Ca2+ influx into the cell to induce cell contraction.

Animals↗
PubMed1979

Feingold dier.

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Humans↗
PubMed1979

The effects of social reinforcement on dominant and dependent mildly intellectually handicapped school-leavers.

The aim of this study was to replicate Exline & Messick's (1967) study of eye-contact interview behaviour with college students on a group of mildly intellectually handicapped students. Twenty subjects (mean CA 14.02 years, SD 0.45 years, mean IQ 72.0, SD 7.6) attending a metropolitan school for the mildly mentally handicapped were classified as dominant or dependent by teacher ratings and sociogram analysis. They were given large or small amounts of reinforcement for eye-contact when interviewed by their teacher. Although the study failed to replicate some of Exline & Messick's findings, results indicated a feedback rather than reward model in explaining the effects of social reinforcement on eye-contact in interviews. Implications for communication training for such intellectually handicapped students is discussed.

Adolescent↗
PubMed1979

Vocalization and looking behaviour of Down's syndrome infants.

The effect of contingent and non-contingent vocal stimulation on vocalization and looking behaviour was investigated for 10 Down's syndrome infants. There were two experimental sessions consisting of four stages, namely 1 min base-line, 1 min experimental condition, a further 1 min base-line and a final 2 min experimental condition. Maternal vocal stimulation was contingent upon infant vocalization for the experimental conditions of one session and was presented every 10 s independent of infant vocalization for the experimental conditions of the other session. Neither condition increased infant vocalization but there was a significant decrease in looking at mother during the base-line stages which followed maternal vocalization (F = 5.07, d.f. = 4, 28, P less than 0.01). It is suggested that looking behaviour may be an important indication of competence in pre-linguistic social communication for developmentally delayed infants.

Child Behavior↗
PubMed1978

Salicylate sensitivity in children reported to respond to salicylate exclusion.

Twelve children, aged six to 13 years, whose parents reported an improvement in behavioural problems with use of the Feingold (K-P) diet for an average period of 12 months, were challenge-tested with 40 mg of acetylsalicylic acid in a double-blind, cross-over trial with ascorbic acid as a placebo. The children were tested within three hours of ingestion of either the experimental or placebo tablet with a battery of psychological and neurological tests, and were rated by a parent on an enlarged Conners' Parent-Teacher Questionnaire for four days after the ingestion of the tablet. It was found that significance was reached in tests of general cognitive capacity, line walking and the "finger-to-nose" tests, as well as increased disturbance in sleep patterns in these children.

Adolescent↗
PubMed1978

Social interactions and communication patterns in mentally retarded children.

An observational approach and videorecordings were used to investigate a group of four mentally retarded kindergarten children with minimal language development. Results showed that when a facilitator (teacher) was present, there were more social interactions and vocalizations, but there was no significant increase in meaningful verbal content. Nonverbal communication rose sharply in the presence of the facilitator. The findings indicate that an observational analysis of patterns of interaction is useful in planning intervention programs in the area of social and communication development.

Aggression↗