Manometry studies in children: minimum standards for procedures.
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Biomedical subjects
Publications and source records attributed to P Hyman.
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Research into behaviours associated with specific syndromes, such as Cornelia de Lange syndrome (CdLS), has neglected to explore the parents' perspective, particularly the potential impact of the notion of behavioural phenotypes on parents' causal explanations. Given the research focus on self-injurious behaviour (SIB) in CdLS, the present study examined parental concern across four topographies of challenging behaviour, causal explanations for these behaviours and optimism for change. As part of a larger study, a questionnaire survey of 86 parents of children and adults with CdLS was conducted. Quantitative data on parental concern and optimism with regard to behaviour problems were collected. Causal explanations for behaviour problems were examined by subjecting open-ended responses to a content analysis. Parents were as concerned about physical aggression and disruptive behaviours as they were about SIB. The majority of parents had deconstructed how CdLS might be associated with SIB in terms of other factors associated with CdLS, such as degree of intellectual disability. Parents did not believe that CdLS influenced SIB more than other challenging behaviours and their beliefs did not effect optimism regarding future change in the behaviour. Despite the focus of research on SIB in CdLS, parents of children and adults with CdLS are also concerned about other challenging behaviours. There was no evidence that a deterministic perspective had been adopted by parents and causal explanations were unrelated to optimism for future change.
In order to study the oncogenesis of melanocytes, transgenic mouse lines were established that express a mutated human Ha-ras (TPras) gene in pigment producing cells. The ras transgenic mice exhibit an altered phenotype, including melanocytic hyperplasia and a muted agouti coat, indicative of hyperproliferative melanocytes. These mice and their wild-type littermates have been subjected to a variety of carcinogenesis protocols, including 7, 12-dimethylbenz-[a]anthracene (DMBA), 12-O-tetradecanoylphorbol-13-acetate (TPA) and UV radiation exposure. Topical DMBA treatment of TPras mice resulted in a high incidence of melanomas. Metastatic lesions were observed in skin, lungs and lymph nodes. TPA treatment of TPras mice induced a small number of papillomas but no nevi or melanomas. UV light exposures induced papillomas in negative littermate and melanomas in some albino TPras mice. These results show that melanocytes expressing an activated Ha-ras in the TPras transgenic mice are susceptible to induction of melanoma by DMBA.
Matched samples of depressed and nondepressed cancer patients were interviewed about past life events, particularly experiences of death and illness. They identified and described any spontaneous intrusive visual memories they had experienced in the past week corresponding to these events. About one quarter reported such memories and, as predicted, the majority of intrusive memories concerned illness, injury and death. The mean levels of intrusion and avoidance were equivalent to patients with post-traumatic stress disorder. Consistent with prediction, depressed patients reported significantly more intrusive memories than controls, and described the memories as typically beginning with or being exacerbated by the onset of depression. Greater numbers of intrusive memories were associated with more maladaptive coping, and greater avoidance with deficits in autobiographical memory functioning.
BACKGROUND: Intrusive memories of stressful events, many involving illness and death, are found in a minority of depressed cancer patients, and may predict the course of anxiety and depression. METHOD: Matched samples of mild to moderately depressed and non-depressed cancer patients were followed up after 6 months. Anxiety and depression at follow-up were related to measures of intrusive memories of stressful life events and autobiographical memory functioning that had been assessed at baseline. RESULTS: Levels of anxiety and depression remained fairly constant over time in the two groups, and the depressed group continued to experience high levels of intrusive memories. The presence of intrusive memories at baseline, and the extent to which these memories were consciously avoided, predicted greater anxiety at follow-up, even after controlling for initial severity of physical and psychiatric symptoms. None of the measures of memory functioning predicted levels of depression at follow-up. CONCLUSIONS: Intrusive memories appear to be a marker of more prolonged psychopathology in cancer patients and may respond to direct therapeutic intervention.
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The tyrosinase promoter has been used to target expression of the mutated human T24 Ha-ras oncogene in pigment-producing cells of transgenic mice. Two independent founder mice carrying the transgene survived and showed the same distinct phenotype of mutated coat color, deeply pigmented skin with multiple nevi, and twirling behavior. The offspring of one of these founders were developed into a line that stably expressed the same phenotype. Histopathological analysis of the tissues revealed hyperpigmentation and/or melanocytic hyperplasia in the skin, eyes, inner ear, and meningeal membranes in the brain. Reverse transcriptase-polymerase chain reaction analysis revealed expression of the transgene in skin, brain, and spleen. We propose that these transgenic mice will be a model for studying the process of multistage melanoma carcinogenesis and a system for evaluating potential chemopreventive agents.
The levels of NAD(P)H:(quinone-acceptor) oxidoreductase (EC.1.6.99.2) (DT-diaphorase) mRNA and enzyme activity have been studied in paired human normal lung and non-small cell lung tumor samples from patients with a history of cigarette smoking. There were significantly higher levels of DT-diaphorase mRNA (1.2 kilobases) in lung tumor compared to normal lung tissue of patients who had stopped smoking more than 6 months before surgery, with relative values (normalized to beta-actin mRNA) of 29.6 +/- 7.8 (SE) in the lung tumor compared to 11.7 +/- 2.2 in normal lung tissue (P < 0.05). There was no significant difference in DT-diaphorase mRNA between lung tumor and normal lung tissue of subjects who were smokers at the time of surgery, with values of 16.5 +/- 2.1 and 15.3 +/- 2.5 (P > 0.05), respectively. DT-diaphorase enzyme activity in normal and tumor lung tissue was positively correlated with DT-diaphorase mRNA (r = 0.908, P < 0.01). The results of the study suggest that DT-diaphorase does not function as an inducible protectant enzyme in human lung against oxidant species and carcinogens present in cigarette smoke. Metabolism of some anticancer drugs by DT-diaphorase can alter their activity. Differences in DT-diaphorase between lung tumors of smokers and past smokers might alter the response to these drugs.
The Luria-Latarjet effect is an increase in resistance of a virus to DNA damage during infection of a host. It has often been assumed to involve recombinational repair, but this has never been demonstrated experimentally. Using nine bacteriophage (phage) T4 mutants, I present evidence indicating that, for phage T4, the Luria-Latarjet effect is due to three repair pathways-excision repair, post-replication-recombinational-repair (PRRR) and multiplicity reactivation (MR) (a second form of recombinational repair). The results also show that the Luria-Latarjet effect develops in two stages. The first stage starts soon after infection. Damage which occurs during the first stage can be repaired by excision repair or PRRR. The second stage appears to start after the first round of DNA replication is complete. DNA damage which occurs during this stage can apparently be repaired by MR as well as the other two repair pathways. The results of this study support the hypothesis that recombinational repair has been selected to ensure that the progeny phage genomes which are packaged have minimum DNA damage. Since other viruses which infect bacterial, animal and plant cells show a Luria-Latarjet effect similar to that in phage T4, the conclusions from this study may have wide applicability.
Endonuclease VII, the product of phage T4 gene 49, has been shown previously to resolve Holliday structures in vitro. Two different processes, genetic recombination and multiplicity reactivation are presumed to have Holliday structure intermediates. Other workers have shown that genetic recombination is reduced in a gene 49 mutant infection. However, in the present study, multiplicity reactivation of UV-irradiated ts or amber mutant phage defective in gene 49 was nearly identical to that of UV-irradiated wild-type phage T4. Thus endonuclease VII is not thought to be essential for multiplicity reactivation of phage T4.
Myelomatous meningitis is a rare occurrence in multiple myeloma. We report 2 cases of documented IgD myeloma with cytologic evidence of meningeal involvement in 1 and detailed paraprotein analysis in both. The occurrence of meningeal involvement in this rare form of plasma cell neoplasm may be more common than previously thought.
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There are numerous tools available to modify the genetic makeup of animals. They are being used to good advantage for studying basic biological phenomena. Within the decade, biomedical products derived from transgenic animals will be available, but the use of this technology for enhancing the quality and efficiency of livestock production will await further refinements in the technology.