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Biomedical subjects

D Francis

Publications and source records attributed to D Francis.

At least 109 records · Page 6Linked to original sources
PubMed1990

Is mucaine an appropriate medication for the relief of heartburn during pregnancy?

A double blind comparative study comparing Mucaine, Mucaine without oxethazaine, and placebo was carried out with 50 patients with symptoms of heartburn during late pregnancy. We found that the 2 active treatments were more effective than placebo for the relief of heartburn, but there was no statistically significant difference between groups for the relief of nausea and regurgitation. There was a significant difference in the percentage of days of use of each medication, with the placebo being used least frequently. Although not statistically significant, for the 3 measures for which placebo differed from the active treatments, patients showed a better response to mucaine. This suggests that the addition of oxethazaine may be of benefit. The lack of statistical significance may be due to the relatively small number of cases, and the findings are promising. No side effects were recorded for any treatment.

Adult↗
PubMed1990

Primary hemangiopericytoma of the lung. Case report.

Hemangiopericytoma is a rare tumor, arising from pericytes. Its outcome is difficult to foretell, as the usual criteria for malignancy are unreliable in this neoplasm. Three cases of primary pulmonary hemangiopericytoma are presented and the pathologic and clinical aspects are briefly reviewed. All three patients were surgically treated, and two are still alive after 7 and 18 years without sign of recurrence or metastasis. The third patient, although still alive, has had three recurrences within 22 months and vertebral metastasis.

Female↗
PubMed1990

Immunohistochemical identification of neuron-specific enolase, synaptophysin, chromogranin and endocrine granule constituent in neuroendocrine tumours.

Immunohistochemical identification of neuroendocrine tumour markers in paraffin embedded material from 22 tumours (5 small cell carcinomas of the lung (SCCL), 12 carcinoids, 2 medullary thyroid carcinomas, 2 pheochromocytomas and one paraganglioma) with electron microscopically verified dense-core granules revealed neuron-specific enolase in all but one tumour, synaptophsin in 15/22 (2 SCCL and 6 carcinoids negative), chromogranin in 16/22 (all SCCL and one carcinoid negative), and endocrine granule constituent in 18/22 (4 SCCL negative). The Grimelius silver methods stained 13/22 (all cases of SCCL and 4 carcinoids negative).

Adrenal Gland Neoplasms↗
PubMed1989

Replicon size and rate of DNA replication fork movement are correlated in grasses.

In eukaryotes, most nuclear DNA replication proceeds bidirectionally from multiple origins of replication. A unit of DNA, replicated by two replication forks from a single origin, is termed a replicon. Using results from DNA fiber autoradiography we show a novel positive correlation between replicon size and the rate of replication fork movement in root meristem nuclei of 13 grass species. Although there is interspecific variation in replicon size, it is balanced by similar variation in the rate of replication fork progression.

Poaceae↗
PubMed1988

A mutant strain of Polysphondylium with defects in many genes.

PN6024 is a mutant strain of P. pallidum which appeared on selection for resistance to MDMP, an inhibitor of translation. It was found to be mutant in four other traits, being resistant to tubercidin, incapable of growth at 31.5 degrees C, abnormal in development, and slow growing at 25 degrees C. Genetic crosses using the macrocyst cycle showed that these five traits are controlled by five unlinked genes. The hypothesis is that movement of a transposon to multiple new locations caused these mutations. A difference in restriction fragment pattern between PN6024 and its parent PN600 support the hypothesis. Attempts were made to find conditions generating other strains like PN6024. Selection for growth in the presence of tubercidin yielded clones which resemble PN6024 in being developmentally abnormal as well as tubercidin resistant. Tubercidin treatment also increased the frequency of clones resistant to canavanine. It is suggested that tubercidin is mutagenic because it causes movement of the putative transposon, not because it generates point mutations. Growth under conditions of stress (at 31.5 degrees C, at 8 degrees C, in the presence of 2% ethanol) had at most an erratic effect in generating strains like PN6024. Three substrains appeared spontaneously in cultures of PN6024. These differed in developmental characteristics from each other and from the parent strain. It is suggested that they carry mutations in genes which control the choices between growth and aggregation, and between aggregation and encystment.

Crosses, Genetic↗
PubMed1988

Familial multiple sclerosis.

Siblings of patients with multiple sclerosis have an increased risk of developing the disease. In this report we describe 3 families with multiple affected members, representing the largest published aggregation of cases in first degree relatives. In the 2 families in which HLA tissue-typing was performed the affected individuals shared part of the haplotype HLA-DR2 (+ HLA-DQW1), BfS (+ C2C), C4A3, C4B1. The implications of these findings for the aetiology of multiple sclerosis are discussed.

Adolescent↗
PubMed1988

Temperature and the cell cycle.

During the period between successive divisions, a cell traverses three stages of interphase: G1 (pre-synthetic interphase), S-phase (DNA synthetic interphase) and G2 (post-synthetic interphase). The time taken for all cells in a meristem to divide (the cell doubling time (cdt] decreases in response to an increase in temperature. For example, the cdt in root meristems of Zea mays decreases 21-fold as the temperature is increased from 3 to 25 degrees C. Whether all phases of the cell cycle alter proportionately with temperature has been ascertained by comparing data from the root meristem of five species: Pisum sativum, Helianthus annuus, Tradescantia paludosa, Allium cepa and Triticum aestivum. In three of the five species there is a disproportionate lengthening of the G1 phase at low temperatures. We suggest that arrest in G1 with the associated 2C amount of DNA, confers maximal protection on the genome of a somatic cell to the stress of low temperature. DNA replication has been studied at different temperatures for Helianthus annuus, Secale cereal and Oryza sativa. The rate of DNA replication, per single replication fork, increases when the temperature is raised, while the distance between initiation points (replicon size) remains constant. The temperature at which the cell cycle has a minimum duration is close to 30 degrees C in many species, and it seems that this optimum temperature is always near the upper temperature limit of the cell cycle. The rate of cell division determines the rates of organ and cell growth. Thus, temperature has a major effect on the way in which meristematic cells are deployed in organogenesis. The rate of organogenesis, in turn, determines the response of the plant to the growing season. We predict that species growing in sub-arctic conditions comprise cells with low DNA contents and hence have the potentialities for rapid cell cycles so that maximum advantage can be taken of a short growing season. Data from Triticum aestivum show that at 5 degrees C, nucleoli are large compared with those at 10-25 degrees C. These observations are consistent with high levels of RNA polymerase and cellular RNA found at low compared with high temperatures. These responses may be important in sustaining growth at 5 degrees C. Finally, the effects of temperature on developmental transitions are discussed. The picture that emerges is that more is known about low, as opposed to high, temperature as a morphogenetic switch but virtually nothing is known about cell cycle activity during such transitions.(ABSTRACT TRUNCATED AT 400 WORDS)

Adaptation, Physiological↗
PubMed1987

Electron microscopy of biopsies from bronchogenic neoplasms.

Bronchial biopsies were investigated by light microscopy (LM) and electron microscopy (EM) with the aim to evaluate if EM could contribute to the LM tumour type diagnosis. Fourty-three pairs of biopsies were comparable. A histogenetic typing, especially of light microscopically undifferentiated and unclassifiable carcinomas, was possible by EM. However, when considering the therapeutical possibilities, at present time, LM tumour classification must be regarded as fully sufficient.

Biopsy↗
PubMed1987

Mutants of Polysphondylium pallidum showing delayed modifications of glycoproteins are altered in a regulatory signal for development.

Binding of a monoclonal antibody, mAb293, to cell-surface glycoproteins of Polysphondylium pallidum is known to be blocked by L-fucose, and Fab of this antibody has been shown to inhibit intercellular adhesion of aggregation-competent cells. Mutants with delayed expression of the carbohydrate epitope, ep293, recognized by the antibody, have been shown to be retarded and altered in cell aggregation. The present study shows that ep293 is a modification of carbohydrate structure that is subject to regulation not only in mutant but also in wild-type cells; ep293 is expressed at an early stage of exponential growth in wild-type and only after 12 h of starvation in mutant PN6002. Proteins are already glycosylated before the epitope is expressed. The developmental regulation of pallidin, a lectin known to be an unglycosylated protein, was investigated in parallel with ep293 using a monoclonal antibody. Pallidin was expressed at about the same time as the carbohydrate epitope in cells of the wild-type as well as the mutant. These results indicate a regulatory signal to which various events are coupled. Induction of ep293 and expression of pallidin are two of these events, and mutants such as PN6002 are altered in the timing of the signal.

Antibodies, Monoclonal↗
PubMed1986

Characteristic and specific histological findings in rheumatoid pleurisy.

The histological findings in rheumatoid pleuritis (RP), as seen in thoracoscopical biopsies, are found to be: A slightly inflamed stroma with a wave-like surface due to vessel-containing flattened papillae. The surface is covered by layers of pseudostratified epithelioid cells and scattered multinucleated giant cells, layers that easily detach as membranes, leaving the stroma surface "naked". These findings, in combination with the absence of mesothelial cell covering, are viewed as characteristic and specific, as based on a blind review of 17 pleural biopsies from RP patients and 14 biopsies from a control group.

Adult↗