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Biomedical subjects

T Matthews

Publications and source records attributed to T Matthews.

87 records · Page 5Linked to original sources

Characterization of antigens in SSV nonproducer cells.

An autologous antiserum against simian sarcoma virus (SSV) nonproducer cells (SSV-NP cells) was characterized by radioimmunoprecipitation. It reacts specifically with two different molecules in SSV-NP cells, a SSV transformation-specific glycoprotein (SSV TrS-gp) and p65, which probably represents a modified gag-precursor.

Animals↗

Abdominal and hepatic uptake of 99mTc-pyrophosphate in neonatal necrotizing enterocolitis.

Abdominal 99mTc-pyrophosphate (99mTc-PYP) scans were obtained in 15 neonates: 12 with neonatal necrotizing enterocolitis (NEC), two with osteomyelitis, and one with myocarditis. Ten of the babies with NEC had at least one positive scan; of these 10 studies, seven (Group A) showed both diffuse abdominal uptake and localized hepatic activity, two (Group B) showed abdominal uptake and questionable hepatic uptake, and one (Group C) demonstrated diffuse abdominal uptake only. The other two babies with NEC had normal scans (Group D). Pneumatosis intestinalis was unquestionably present in two patients from Group A and one from Group B. Upon resolution of the clinical findings, all NEC patients had normal scans. A patient with myocarditis had hepatic uptake of 99mTC-PYP while the abdominal scan in the two infants with osteomyelitis was normal. These preliminary observations suggest that further study of a relationship between abdominal scan findings and the course of NEC is warranted.

Abdomen↗

Immunologic control of the ascites form of murine adenocarcinoma 755. V. Antibody-directed macrophages mediate tumor cell destruction.

An in vitro assay has been developed that mimics the potent in vivo protective capacity of B6 anti-AD755a serum in a passive therapy protocol. In the presence of small volumes of hyperimmune serum or IgG2a antibody, thioglycollate-elicited B6 mouse peritoneal cells (PEC) inhibit the growth of AD755 Cl.10 target cells and other cells provided that they express FLV-related antigens. When hyperimmune serum is replaced by normal serum, or elicited PEC from BALB/c mice are used, growth inhibition of the AD755 Cl.10 target cells is not seen. The latter is in accord with the inability to protect BALB/c mice with the anti-AD755a serum. Tumor cells to which antibody has been pre-bound are not inhibited by thioglycollate-elicited B6 PEC, analogous to the undiminished tumorigenicity of antibody-bound AD755a cells in vivo. These results, along with those presented in the accompanying papers, have led to the construction of a model to explain the specificity and mechanism of the potent in vivo passive protection characteristic of this system. The major features of this model are that the protective IgG2a antibody must first interact with an appropriate host effector cell, presumably of the monocyte/macrophage lineage, and that such an antibody-directed cell then binds to the tumor cell and effects its elimination, possibly by a phagocytic mechanism.

Animals↗

In vitro translation of the Two RNAs of Nodamura virus, a novel mammalian virus with a divided genome.

Nodamura virus is a small ribovirus containing two RNA molecules. Both RNAs were found to be active messengers for protein synthesis in cell-free extracts prepared from wheat embryo or HeLa cells. RNA 2 directed synthesis of a 43,000-dalton product, p43, whose tryptic fingerprint was similar to that of the major viral coat protein, vp40 (molecular weight, 40,000). Though p43 appears to be a precursor of vp40, processing did not occur in the cell-free extracts. RNA 1 directed synthesis of a 105,000-dalton protein, p105. Its tryptic fingerprint revealed no evidence of coat protein sequences. Hence, the two RNAs represent genes with few, if any, redundant coding sequences.

Amino Acids↗

Further investigation of Coleman's Level Hypothesis.

Volunteers (16 male and 17 female) from introductory psychology courses were used to investigate Coleman's rationale in support of the Levels Hypothesis. Projective stimuli from parts of the Rorschach, TAT, and Sentence Completion techniques were presented, and subjects asked to rate how much the stimuli and their responses said something about themselves, their fathers, or mothers, to determine their awareness of the personal relevance of the stimuli and responses. Results indicated that both the stimulus and response ratings varied as expected at the .01 level of significance, thus supporting Coleman's rationale.

Journal Article↗

A national model of care service for professionals dealing with sudden infant death.

Sudden Infant Death Syndrome (SIDS) is any death occurring in an infant or young child which is unexpected by history and in which a thorough post mortem examination fails to demonstrate an adequate cause of death. The National Sudden Infant Death Register collects information on all sudden unexpected deaths in infants and young children occurring in Ireland. In this study, a comparison was made between parent's experience of professional services in the aftermath of their child's death both before and after the implementation of a National Model of Care for professionals in 1995. In addition, a random sample of 105 professionals were surveyed about their knowledge of the Model of Care services. Results were grouped according to the parental experience of the emergency services, the hospital services, the community services and the bereavement support services offered to parents. Prior to the implementation of the Model of Care Service (MOC) (1992-1994), 14 per cent of families stated that they did not find the Gardai helpful. After the Model of Care, only 7 per cent of parents expressed such dissatisfaction. Prior to the MOC, only 3 per cent of Gardai provided families with an information booklet on sudden infant death but afterwards, 23 per cent of Gardai did so. After the MOC families were more likely to have been given the opportunity to hold their infant, were given more privacy and were offered more keepsakes of their infant. Only 46 per cent of families were offered momentos of their baby prior to the MOC as compared to 84 per cent after the implementation of the MOC. They were also more likely to perceive the ancillary services such as the Gardai in a more positive light, where 22 per cent of Gardai offered the family the ISIDA support booklet compared to a previous 3 per cent. Over 50 per cent of parents were provided with a special room in the hospital following the MOC as opposed to a previous 48 per cent. Twenty-one per cent of parents prior to the MOC described the conditions in the hospital as awful, poor or fair, however 31 per cent of parents stated this after the MOC. While there have been improvements in certain areas, there still remains considerable variation in the quality of service provided to all parents. Specifically, we need to address the fact that 16 per cent of parents still report a difficulty in obtaining post-mortem information. Almost 40 per cent said they had little input into how their child was dressed or laid out at this highly emotive time. Over one-third of parents stated they were concerned about how few of their primary health providers, namely general practitioners and public health nurses called to visit them in the aftermath of this tragic event.

Delivery of Health Care↗

Antiviral activity and mechanism of action of ganciclovir.

Ganciclovir (9-[(1,3-dihydroxy-2-propoxy)methyl]guanine) is a potent inhibitor of viruses of the herpes family, including cytomegalovirus (CMV), that are pathogenic for humans and animals. The primary mechanism of ganciclovir action against CMV is inhibition of the replication of viral DNA by ganciclovir-5'-triphosphate (ganciclovir-TP). This inhibition includes a selective and potent inhibition of the viral DNA polymerase. Ganciclovir is metabolized to the triphosphate form by primarily three cellular enzymes: (1) a deoxyguanosine kinase induced by CMV-infected cells; (2) guanylate kinase; and (3) phosphoglycerate kinase. Other nucleotide-metabolizing enzymes may be involved as well. The selective antiviral response associated with ganciclovir treatment is achieved because of the much weaker inhibition of cellular DNA polymerases by ganciclovir-TP. Activity and selectivity are also amplified by the accumulation of ganciclovir-TP in CMV-infected cells.

Acyclovir↗

Comparison of intravenous glucose and fat calories on host and tumor growth.

This study was undertaken to determine if the proportions of intravenous carbohydrate and fat calories influence the relative growth of a Walker 256 carcinosarcoma and its host. Rats injected intraperitoneally with Walker 256 carcinosarcoma cells were randomized into three total parenteral nutrition (TPN) groups, G/AA in which glucose provided all nonprotein calories, G/F/AA in which the nonprotein calories were 20% fat and 80% glucose, and F/AA in which all nonprotein calories were from fat. Except for the caloric source, TPN for each group was identical. A fourth group was sham operated, fed rat food, and was not given TPN. On the 6th day after inoculation, the tumor in each rat showed a dispersed ascites form as well as a solitary mass form involving the omentum. The total number of tumor cells in the ascitic fluid and the dry weight of the mass were determined. The three TPN groups did not differ in tumor cell count, solid tumor weight, ratio of tumor cell count to final host weight, or ratio of solid tumor to final host weight. The mean ratio of ascites tumor cell count to host weight was not different between the rat food-fed group and any of the TPN groups. The mean ratio of solid tumor to host weight was less for the TPN groups than for rat food-fed animals. We conclude that TPN had no adverse effect on the growth of tumor vs. host and that the source of intravenous calories (fat or carbohydrate) did not influence the relative growth of tumor and host in this TPN-tumor model.

Animals↗

Neonatal abstinence syndrome.

A 12 month review of infants admitted with neonatal abstinence syndrome to a neonatal intensive care unit was undertaken. The relationship of maternal drug abuse to symptoms, the effectiveness of pharmacologic agents in controlling symptoms and the length of inpatient stay were investigated. A retrospective review of maternal and infant records was performed. Those infants with a serial Finnegan score greater than 8 were treated. Pharmacologic treatment was oral morphine sulphate (0.2 mg 4-6 hourly), phenobarbitone (3-7 mgs/kg/day), or combination of the above. 43 infants were admitted to the hospital during the year. The average maternal age was 24.6 years, (18-34 years). Drug use volunteered by the mothers was methadone alone in 6 cases, methadone and benzodiazepines in 14, methadone and heroin and benzodiazepines in 7, methadone and heroin in 10, heroin alone in 2, and other multiple drug use including oral morphine sulphate, dothiepin and cannabis in 4. Average gestational age was 40.3 (35-42 weeks). The average birthweight was 2.81 kgs (1.89-3.91 kgs). Time to onset of withdrawal symptoms was 2.8 (1-13) days. The duration of pharmacologic treatment (oral morphine sulphate and/or phenobarbitone) was 21.8 (1-62) days. The total hospital stay for the 43 infants was 1,011 days. This study confirms that polydrug abuse is the commonest type of drug abuse in Dublin. The duration of withdrawal symptoms is loosely related to drug type, but increasing duration of symptoms is noted for infants exposed to benzodiazepines. Our experience would favour the use of morphine sulphate to treat pure opiate withdrawal symptoms. Over the 12-month period, there was an average occupancy of 3 beds per day in the paediatric department.

Adolescent↗

Safety of home delivery compared with hospital delivery in The Eastern Region Health Authority in Ireland in the years 1999-2002.

A comparison was made of deaths from intrapartum hypoxia of normally formed babies > 2.5 kg born at home (N = 346) and those born in hospitals (N = 61,215). If the intended place of birth is home the chance of dying due to intrapartum hypoxia is 1:70 (5 in 346). If the intended place of birth is hospital the chance of dying is 1:3600 (17 in 61,215). Although the sample size of home births is smaller, the difference is significant (< 0.01 level of significance). In view of the small number of home births, the need for ongoing monitoring of home births over a longer period is essential.

Delivery Rooms↗

The Dublin outcome for low birth-weight infants.

This report describes outcomes for all infants with birth weight 501-1750 grams born in the three major maternity hospitals in Dublin between 1.1.90 to 31.12.91. 37,958 mothers delivered 38,498 infants during this period, consisting of approximately 36% of all deliveries in Ireland. 633 (1.6%) of all infants born weighed 501-1750 grms. 102 (16%) were stillborn and 28 of the 531 live born infants had lethal malformations. 30% of women received two or more doses of antenatal steroids before delivery and a highly significant negative correlation occurred between the need for ventilation after birth and antenatal steroids. 56.4% of babies were delivered by caesarean section as compared with 10.8% of the hospital population. Of 503 liveborn infants without lethal malformation. 426 (85%) survived to 28 days and 419 (83%) to discharge home. 15% were growth retarded. 46% of infants were ventilated, mean duration of ventilation was 7 days. 25% of infants had an intraventricular haemorrhage, 10% necrotising enterocolitis and 19% culture proven sepsis. 15% of survivors developed broncho pulmonary dysplasia and 12% retinopathy of prematurity. This paper describes important information for mortality, morbidity and interventions among a large population of low birth weight infants in Ireland and can be used as a basis against which to compare future alterations in practice. It demonstrates a clear benefit for antenatal steroids in decreasing the need for ventilation and the importance of ensuring their utilisation antenatally where possible.

Female↗