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Biomedical subjects

A Gibbs

Publications and source records attributed to A Gibbs.

At least 19 recordsLinked to original sources
PubMed2026

Is There Potential Clinical Utility in Reporting Variants of Uncertain Significance From Prenatal Sequencing?

OBJECTIVE: Prenatal sequencing of fetuses with abnormalities detected on imaging is expanding globally. Debate continues over whether variants of uncertain significance (VUS) should be reported prenatally, with some recent national position statements opposing this. In England, VUS that fit the fetal phenotype and require little further evidence for upgrade are discussed at multidisciplinary team (MDT) meetings to determine whether to report. We review the VUS reported by one English laboratory that provides prenatal sequencing to half of England. METHOD: The laboratory's database was searched from 01/10/2020 to 30/04/2025 to ascertain all cases where a VUS was reported. Pregnancy outcomes were obtained from local clinical teams to determine whether the VUS status had been resolved. RESULTS: VUS were reported in 41/881 fetuses sequenced. Follow-up data were available for 38/41 cases, of which 23 were subsequently upgraded to likely pathogenic and 1 downgraded to likely benign. The most common reason for upgrade was new information from post-mortem or postnatal review (17/23). CONCLUSION: There is clinical utility in reporting VUS from prenatal sequencing following MDT discussion. Although reporting VUS leaves parents with uncertainty, follow up (including post-mortem when applicable) resolves this in over 50% of cases (79% of cases re-examined pre- or postnatally).

Humans↗
PubMed1992

Origins of genes: "big bang" or continuous creation?

Many protein families are common to all cellular organisms, indicating that many genes have ancient origins. Genetic variation is mostly attributed to processes such as mutation, duplication, and rearrangement of ancient modules. Thus it is widely assumed that much of present-day genetic diversity can be traced by common ancestry to a molecular "big bang." A rarely considered alternative is that proteins may arise continuously de novo. One mechanism of generating different coding sequences is by "overprinting," in which an existing nucleotide sequence is translated de novo in a different reading frame or from noncoding open reading frames. The clearest evidence for overprinting is provided when the original gene function is retained, as in overlapping genes. Analysis of their phylogenies indicates which are the original genes and which are their informationally novel partners. We report here the phylogenetic relationships of overlapping coding sequences from steroid-related receptor genes and from tymovirus, luteovirus, and lentivirus genomes. For each pair of overlapping coding sequences, one is confined to a single lineage, whereas the other is more widespread. This suggests that the phylogenetically restricted coding sequence arose only in the progenitor of that lineage by translating an out-of-frame sequence to yield the new polypeptide. The production of novel exons by alternative splicing in thyroid receptor and lentivirus genes suggests that introns can be a valuable evolutionary source for overprinting. New genes and their products may drive major evolutionary changes.

Biological Evolution↗
PubMed1992

Familial mesothelioma. Details of 17 cases with histopathologic findings and mineral analysis.

Nine new cases of mesothelioma clustering in four families are described, and additional information is provided on four previously reported families. All of the members of these families had some exposure to asbestos. Diagnoses were confirmed histologically, and the relevance of the histologic pattern is discussed after the literature review. The lung mineral fiber burden was quantified in patients by transmission electron microscopic examination and energy-dispersive x-ray analysis, and this confirmed significant exposure to amphibole asbestos in all patients. Evidence supporting an increased incidence of mesothelioma in family members is discussed.

Aged↗
PubMed1992

Comparisons of the genomic sequences of erysimum latent virus and other tymoviruses: a search for the molecular basis of their host specificities.

The nucleotide sequence of the genome of erysimum latent tymovirus (ELV) has been determined. It closely resembles those of the other four sequenced tymoviral genomes in its gene organization and composition, but is the smallest (6034 nucleotides) and most distinct of them. Furthermore the 78 non-coding nucleotides at the 3' terminus of the ELV genome are unable to form a complete tRNA-like structure like that reported for other tymoviruses. Comparisons of the five tymovirus genomes and their encoded proteins indicate that they have probably evolved from the progenitor tymovirus by independent progressive mutational change without genetic recombination. Comparisons of the sequences of the two non-virion proteins of five tymoviruses, and virion proteins of 17 tymoviruses, revealed no specific similarities between those of ELV and turnip yellow mosaic virus that could explain why their host ranges and symptoms are so similar, yet differ, in this respect, from ononis yellow mosaic, kennedya yellow mosaic and eggplant mosaic tymoviruses.

Amino Acid Sequence↗
PubMed1992

Bacterial toxins: a possible cause of cot death.

AIM: To test the hypothesis that sudden infant death syndrome (SIDS) may be caused by toxins of commonly occurring bacteria in infants lacking developed immunity. METHODS: Nasopharyngeal microbial isolates from 22 pairs of SIDS cases and healthy infants matched for age (by month), sex, and sampling time (by month) were compared for lethal toxigenicity. Crude toxin preparations were made from isolates cultured on dialysis membrane overlaid on agar, and these preparations were then tested for lethality by intravenous injection into 11 day old chick embryos. RESULTS: Fifteen (68%) of the SIDS cases were each found to have at least one lethally toxigenic organism in their nasopharyngeal flora; only eight (36%) of the flora of normal infants included a lethally toxigenic species. CONCLUSION: Infants who have died of SIDS have a significantly higher (p less than 0.05) probability than matched healthy infants of having a lethally toxigenic bacterial species in their nasopharyngeal flora.

Bacteria↗
PubMed1992

Lethal synergistic action of toxins of bacteria isolated from sudden infant death syndrome.

AIM: To test the hypothesis that lethal toxins of bacteria associated with sudden infant death syndrome (SIDS) can act synergistically. METHODS: Bacteria occurring together in the nasopharynx of cases of cot death were studied. The lethal toxicity of crude toxin preparations was determined over a range of dilutions by injections into the chorioallantoic vein of the chick embryo. Toxin preparations of low lethality for the chick embryo SIDS model were then tested in combination. RESULTS: Staphylococcus aureus toxin preparations showed low lethality when tested alone, even at low dilution. At 1 in 100 dilution S aureus toxin was lethal to one out of 15 chick embryos. Escherichia coli toxin preparations showed high lethality except on high dilution (1 in 80) when lethality fell to two out of 15 of chick embryos. When the same toxin preparations were tested simultaneously in combination, lethality rose to 14 out of 15. Similar findings were observed over a range of toxin dilutions. This finding was highly significant (p = 0.0012). CONCLUSIONS: That synergy between toxins can enhance the lethality of toxins elaborated by bacteria associated with SIDS.

Animals↗
PubMed1991

Optimal conditions for the analysis of Pasteurella haemolytica lipopolysaccharide by sodium dodecyl sulphate-polyacrylamide gel electrophoresis.

The optimal conditions for the analysis of the lipopolysaccharide (LPS) of two serotype A1 isolates and a serotype A2 isolate of Pasteurella haemolytica by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and silver staining were determined. The LPS of the A1 isolates possessed O side chains, consisting of high molecular mass bands with the appearance of a ladder-like pattern, as well as a low molecular mass core-oligosaccharide region; the LPS of the A2 isolate consisted only of the core-oligosaccharide region. Furthermore, the LPS of the two A1 isolates differed in the core-oligosaccharide region. Optimal resolution of low molecular mass LPS components was obtained in a 15% acrylamide resolving gel containing 4 M urea whereas optimal resolution of high molecular mass components was obtained when urea was omitted. Conventional silver staining resulted in excellent visualisation of LPS bands, whereas a modified staining method did not detect additional bands, as has been demonstrated with the LPS of Pseudomonas aeruginosa. Proteinase K digestion of outer membranes gave more clearly defined LPS profiles than did similar digestions of whole cells, and more closely resembled the profiles of purified LPS. With the exception of slight variation in the average molecular mass of a group of O side chains between logarithmic and stationary phases there were no differences in LPS profiles at various stages of the growth cycle; freezing and thawing of LPS samples had no effect on the profiles.

Animals↗
PubMed1991

Violence in pregnancy.

Statistics available in the UK and in North America indicate that violence towards women by their partner is widespread but under-reported. Research shows that violence is likely to begin or escalate during pregnancy. It is suggested that violence to pregnant women may be more common than gestational diabetes or placenta praevia, and that it may be responsible for miscarriage, preterm labour and fetal injuries. This paper examines attitudes prevalent in society towards abused women, considers the psychological consequences of their abuse and the inherent difficulties women face when they try to leave a relationship with a violent partner. It also describes how midwives may recognise women who have been abused by their partner and suggests the development of strategies to help such women.

Female↗
PubMed1991

Epidemiological analysis of a methicillin-resistant Staphylococcus aureus outbreak using restriction fragment length polymorphisms of genomic DNA.

The genomic DNA of 58 isolates of methicillin-resistant Staphylococcus aureus (MRSA) obtained during an infection outbreak at two major Canberra hospitals was analysed for restriction fragment length polymorphism (RFLP) by digestion with the endonuclease SmaI and resolution of the fragments by pulsed-field gel electrophoresis. Based on the fraction of common fragments generated by the endonuclease, DNA similarities among the isolates were estimated. Distance matrix analysis showed that the MRSA isolates could be divided into two major clusters (RFLP types I and II) and one minor one (type 46). A fourth group of miscellaneous isolates was found to be heterogeneous in terms of DNA sequence similarity. The epidemiological data indicated that RFLP type I was most common in the intensive care units in the two hospitals, with particular subtypes of RFLP type I concentrated in individual units. RFLP type II and the miscellaneous group were more generally distributed. Type 46 isolates appear to be related to a group which was present in epidemics in Melbourne hospitals in the early 1980s. Using the standard phage set, the RFLP type I group was largely untypable. However, type II isolates were all phage typable, with a shared susceptibility to phages 29/85/95/90; type 46 isolates had a shared susceptibility to phages 85/90. The miscellaneous isolates were of variable phage types.

Australia↗
PubMed1991

Cultural and political limitations within a rational approach towards educational change.

This paper considers the use of a rational curriculum planning model within nurse education. It suggests that the process of change within the model is oversimplified and mechanistic. As such it denies or ignores the experience of individuals involved in the change process by reducing their personal, cultural and political realities to a level of idealogical control. The unrestrained or unmodified application of a rational approach may, by this control, inhibit the development of change arising from subjective experiences. It may further be viewed as a political strategy which benefits powerful groupings within the school thus institutionalizing this power and maintaining the status quo in terms of power and influence.

Conflict, Psychological↗
PubMed1990

The tymobox, a sequence shared by most tymoviruses: its use in molecular studies of tymoviruses.

The 5'-terminal sequences of the virion protein mRNAs of ononis yellow mosaic and kennedya yellow mosaic tymoviruses were determined, and also the positions in the genomes of the transcription initiation sites of those mRNAs. Comparisons of the available genomic sequences of tymoviruses revealed two conserved regions, one at the initiation site and another longer sequence of sixteen nucleotides to the 5' side of it. The longer sequence, which we call the tymobox, was tested as a target for a designed ribozyme, which cleaved appropriate genomic fragments of three tymoviruses. A synthetic oligonucleotide with sequence complementary to the tymobox was shown to be a tymovirus-specific probe for diagnosing and identifying tymoviruses, except for wild cucumber mosaic tymovirus. The tymobox sequence was also used as a primer for the second strand DNA synthesis of dsDNA representing the virion protein gene of cacao yellow mosaic tymovirus, a tymovirus with unknown sequence. Thus, the tymobox is a useful tool in molecular studies of tymoviruses.

Base Sequence↗
PubMed1990

A quantitative assessment of somatostatin-like and neuropeptide Y-like immunostained cells in the frontal and temporal cortex of patients with Alzheimer's disease.

Immunocytochemical studies utilizing radioimmunoassay and morphological techniques have provided conflicting evidence for the involvement of somatostatin and neuropeptide Y in Alzheimer's disease (AD). However, previous investigators have not considered the effects of cortical atrophy in AD tissue on their findings. This study reports the numbers of somatostatin-like (SLI) and neuropeptide Y-like immunoreactive (NPYLI) neuronal perikarya and the length of SLI and NPYLI immunoreactive fibres, with appropriate corrections for atrophy in 6 control and 6 AD cases. There were significantly fewer SLI neurones in AD in layers II + III combined from the temporal cortex, and fewer NPYLI neurones in layers V + VI in both frontal and temporal cortices. Using a randomized method to quantify immunostained fibre length in the neuropil, an analysis of variance revealed no significant differences in the mean SLI or NPYLI fibre length per cortical strip between control and AD groups in frontal or temporal cortex. However, using a second measure of fibre length by tracing the fibres attached to consecutive immunostained perikarya, there were significant reductions in the AD brains in the mean fibre length per cell in layers V + VI for SLI in the temporal cortex, and for NPYLI in the frontal cortex. This reduction in fibre length per individual cell was presumably masked by the large variation in the fibre length found between cases using the randomized approach. It was concluded that in order to evaluate the involvement of these neuropeptides in AD from any measurements of concentration, it is essential to include some compensation for the extent of cortical atrophy that occurs with the disease.

Aged↗
PubMed1990

Early HIV-related neuropsychological impairment: relationship to stage of viral infection.

Sixty male outpatients with no past neuropsychiatric history were examined for evidence of early HIV-related neuropsychological impairment. Significant cognitive deficit, as measured by the RAVLT and WAIS-R Digit Symbol Substitution tests, and moderate correlation with indices of immune function, were observed in a group of patients with AIDS-Related Complex [ARC]. Patients with asymptomatic HIV-infection demonstrated no significant differences in performance compared to a group of HIV-seronegative controls. No significant group differences in age, education, predicted-IQ or self-rated depression and anxiety were observed. These results support the hypothesis that HIV-related cognitive disturbance occurs within the context of immunosuppression.

AIDS Dementia Complex↗
PubMed1990

The primary structure of the virion protein gene and encoded protein of erysimum latent tymovirus.

The nucleotide sequence of the virion protein (VP) gene of erysimum latent tymovirus (ELV) has been determined and the amino acid sequence of the VP deduced and confirmed by peptide analysis. The ELV VP is larger than the VPs of other tymoviruses because it has, unexpectedly, 11 more amino acid residues at its N terminus. The amino acid sequences of the VPs of ELV and four other tymoviruses align unequivocally and their relationships, as assessed from the percentage of identical residues, correlate well with previously reported serological tests which have shown ELV to be distant from other tymoviruses.

Amino Acid Sequence↗
PubMed1990

The nucleotide sequence of the genomic RNA of kennedya yellow mosaic tymovirus-Jervis Bay isolate: relationships with potex- and carlaviruses.

The nucleotide sequence of the genomic RNA of kennedya yellow mosaic tymovirus-Jervis Bay isolate (KYMV-JB) has been determined. The genome of KYMV-JB is 6362 nucleotide residues long and encodes three major open reading frames. The genomic organization and the encoded proteins of KYMV-JB are very similar to those of three other tymoviruses that have recently been reported. Sequence comparisons revealed that the possible replicase proteins of tymoviruses are closely related to those of potexviruses and carlaviruses, suggesting a close evolutionary relationship among these viruses, despite differences in their genome organization and particle morphology.

Amino Acid Sequence↗
PubMed1990

Aspects of communication with people who have attempted suicide.

This paper addresses some potential difficulties in communication which may occur between health-care professionals and those who are being assessed following an unsuccessful suicide attempt. Attitudes towards suicide and attempted suicide which may be held by the patient and carer are reviewed and the effects that these may have on communication, particularly at the assessment stage, are considered. Some techniques to enhance communication and assessment are proposed.

Attitude of Health Personnel↗