PubMed Health⌕ Search

Biomedical subjects

O Jonas

Publications and source records attributed to O Jonas.

12 recordsLinked to original sources
PubMed2001

Development of a novel probe for measuring drug binding to the F1*S variant of human alpha 1-acid glycoprotein.

A novel probe was developed to measure drug association with the F1*S variant of the human serum protein alpha 1-acid glycoprotein (AGP). The molecule 2-hydroxy-3,5-diiodo-N-[2(diethylamino)ethyl]benzamide (DEDIC) binds to AGP, quenching its native fluorescence. This quenching was fitted to a two-site model giving apparent dissociation constants of 0.049 +/- 0.005 and 12 +/- 2 microM (mean +/- SEM). Quenching of each of the separate variants of AGP by DEDIC was itself described by a two-site model, giving for the F1*S variant K(D)(1)((F1*S)) = 0.041 +/- 0.010 microM and K(D)(2)((F1*S)) = 29 +/- 7 microM; and for the A variant K(D)(1)((A)) = 0.31 +/- 0.18 microM and K(D)(2)((A)) = 8.8 +/- 0.7 microM. The utility of DEDIC in probing drug interactions with isolated variants was demonstrated in competition experiments with the model drugs amitriptyline and bupivacaine. In addition, the selectivity of DEDIC for variant F1*S rendered it capable of probing the binding of drugs (including the variant A-selective drug amitriptyline) to F1*S in a mixture of variants, such as occurs naturally in whole AGP. DEDIC is unique as an F1*S variant-selective probe of drug binding to whole AGP that is also sufficiently soluble to serve as a probe of drug binding to the lower affinity sites on isolated A and F1*S variants.

Anesthetics, Local↗
PubMed1993

Breech presentation in South Australia, 1987-1989.

This study compares the maternal, obstetrical, labour and pregnancy outcome characteristics of 2,412 breech-presenting births with 17,946 vertex-presenting births. Mothers of babies presenting as breeches were significantly more likely to have had a previous miscarriage, an obstetric complication, a threatened miscarriage or threatened labour during the current pregnancy, or Caesarean section than mothers of babies with vertex presentation. The babies presenting as breeches had significantly more neonatal morbidity and perinatal mortality. They showed higher rates of suspected intrauterine growth retardation, prematurity, low birth-weight, low Apgar scores and congenital anomalies. The overall perinatal mortality for breech presentations was almost 9 times higher than for vertex presentations. Unconditional multiple logistic regression analysis showed that, even after adjusting for low birth-weight and the presence of congenital anomalies, breech presentation still showed a statistically significant association with perinatal death. The study alludes to the possibility that breech presentation, in a significant number of cases, may not be coincidental but a marker for some preconceptional or prenatal disturbance. The study also shows an excess of breech presentations in females which is unexplained and may point to a genetic or hormonal susceptibility of the fetus.

Adult↗
PubMed1992

The association of low socio-economic status in metropolitan Adelaide with maternal demographic and obstetric characteristics and pregnancy outcome.

The South Australian perinatal statistics collection for 1988 was used to consider the association of low socio-economic status in metropolitan Adelaide (South Australia) with maternal demographic and obstetric characteristics and pregnancy outcome in 12047 singleton births. Socio-economic status--low, middle or high--was inferred from the socio-economic rating of the postcode of residence. Chi-squared analyses were carried out to test for significant trends in proportions of pregnancy and pregnancy outcome variables across the socio-economic groupings. There was trend for the proportions of adverse obstetric and perinatal outcomes to decrease with increasing level of socio-economic status. Logistic regression analysis, adjusted for maternal age, marital status, race, parity and gestational age, confirmed the findings of the trend analyses, namely that mothers from the poor socio-economic areas were at a greater risk for poor pregnancy outcome. These poor outcomes included Apgar scores of less that 7 at both 1 and 5 minutes after birth, delay in onset of regular breathing of 5 minutes or longer; the need for intubation; the use of narcotic antagonists; low birthweight of under 2500 g; the need for special nursey care; and neonatal death.

Adult↗
PubMed1992

The association of maternal and socioeconomic characteristics in metropolitan Adelaide with medical, obstetric and labour complications and pregnancy outcomes.

Multiple regression analysis was used to measure associations of maternal age, race, gravidity, marital status and socioeconomic status with medical problems and pregnancy outcomes. The study population comprised all singleton births to residents of metropolitan Adelaide (in South Australia) during 1988 that were included in the State's perinatal statistics collection. The results indicate that in metropolitan Adelaide, low socioeconomic status is related to a higher risk profile of mothers and babies. It also highlights that there is a strong association of divorce and separation with medical problems and an adverse pregnancy outcome. Poorer outcomes are also seen in never married women, teenage women, older women, non-Caucasian women and primigravid women. These poorer outcomes in older women and primigravidas include higher risks of low birth-weight and prematurity of their babies. The study also demonstrates that groups that are less likely to have choice of obstetric care, eg. teenage women, non-Caucasian women, and women of low socioeconomic status, have a lower odds of obstetric intervention as characterized by nonspontaneous labour and elective Caesarean section.

Adult↗
PubMed1991

Pregnancy outcomes in primigravid women aged 35 years and over in South Australia, 1986-1988.

The South Australian perinatal data collection for 1986-1988 was used to compare the characteristics and outcomes of singleton pregnancies in 515 primigravid women aged 35 years and over with those in 4175 younger primigravid women aged 20-29 years. Notable differences observed were a higher prevalence of medical, obstetric and labour complications and assisted deliveries in the older group. Breech presentations were almost twice as common in the older women, as were caesarean sections. Only 27% achieved a spontaneous vaginal delivery. The mean duration of hospital stay for the older women was longer for both vaginal and caesarean deliveries. However, although their babies were more likely to be premature or of low birthweight, the perinatal mortality rate was not significantly increased and the great majority of older primigravid women managed by modern obstetric methods can expect a good pregnancy outcome.

Adult↗
PubMed1990

Pregnancy and perinatal factors associated with persistently low Apgar scores: an analysis of the birth records of infants born in South Australia.

This study included all newborns with Apgar scores below seven at one minute after birth who were born in 1986 and whose births were notified to the South Australian Perinatal Statistics Collection. Univariate comparisons were made of the demographic, obstetric and pregnancy outcome characteristics of the 301 newborns whose Apgar scores remained below seven at five minutes and the 3165 whose scores recovered to seven or more. The results provide a general risk profile of the 301 newborn infants who perform poorly at birth, as indicated by a low Apgar score at both one and five minutes. Adverse risk factors identified in this study were similar to those for intellectual disability (mental retardation) and cerebral palsy in South Australia. It is suggested that persisting low Apgar scores, when combined with the other risk factors demonstrated in this and previous studies, would provide more reliable prognostic information than would Apgar scores alone. The study also shows that the majority of infants with low Apgar scores at one minute scored seven or better at five minutes. This demonstrates, that although a low one minute Apgar score has value in identifying newborns in need of immediate attention, it must be supplemented by the five minute score's stronger association with perinatal morbidity.

Apgar Score↗
PubMed1989

Pregnancy and birth risk factors for intellectual disability in South Australia.

It is generally accepted that developmental handicaps can often be minimized through early detection and intervention. For this reason, it is normal practice in many hospitals to follow-up and screen infants who present at birth with established risk factors. Clinical judgement will always be important when selecting children for follow-up. However, as hospital data systems improve, automated systems could be developed for listing children potentially "at risk". Where initial clinical decisions not to follow-up individual children prove to be at odds with this automated output, the individual child could be re-assessed clinically. This process could increase the level of quality control. An initial risk-factor model for intellectual disability has been developed, based on the South Australian Perinatal Statistics Collection, for use in this context.

Australia↗
PubMed1989

A South Australian study of pregnancy and birth risk factors associated with cerebral palsy.

Using the Perinatal Statistics Collection compiled by the Pregnancy Outcome Unit of the South Australian Health Commission, a profile of statistically significant risk factors for cerebral palsy has been established for a South Australian population. Logistic regression analysis revealed that these factors included threatened miscarriage, ante-partum haemorrhage, maternal age of under 20 years, shortened gestational age, low birthweight, low Apgar score at 5 minutes, foetal distress, delay in establishing spontaneous regular respiration, presence of a congenital abnormality and prolonged hospital stay. In addition, pregnancy hypertension, reduced number of antenatal visits, breech presentation, resuscitation of the neonate by intubation and intermittent positive pressure ventilation, and the need for specialised nursery care were found to be significant in univariate analyses. These data point to the risk factors which may help identify infants who require closer monitoring for early signs of cerebral palsy.

Adult↗
PubMed1989

Caesarean section in South Australia, 1986.

A profile of Caesarean section in South Australia was obtained by analysing the 19,800 births in the perinatal statistics collection in 1986. The Caesarean confinement rate was 19.0%, of which 9.0% were elective sections and 9.9% emergency sections. The rates were highest in large metropolitan hospitals. Elective rates were highest in metropolitan private hospitals, among older women, among those with a previous perinatal death or where a fetal malpresentation occurred. Emergency sections were more common in primigravidas, non-Caucasian women, those with a poor pregnancy history, few antenatal visits and a medical or obstetric complication of pregnancy. The obstetric complications most commonly encountered with Caesarean sections were fetopelvic disproportion, fetal distress, malposition or malpresentation, pregnancy hypertension and uterine inertia. Neonates born by emergency section were more likely to be premature, or low birth-weight and to manifest depression of vital signs compared with vaginal births. They also required more intensive resuscitation and neonatal care, and neonatal death occurred more frequently. Morbidity was much lower in neonates born by elective than emergency section.

Adult↗
PubMed1975

ipecacuanha-ipecauanha.

A survey was conducted among patients attending the casualty department of the Adelaide Children's Hospital to find the length of time which elapsed between the ingestion of a potentially toxic substance and the institution of measures to evacuate the stomach contents. This paper demonstrates that there is often an undue delay before effective treatment is instituted. To overcome this delay, the administration of syrup of ipecacuanha in the home as a first-aid measure in the management of accidental poisoning is advocated.

Accidents, Home↗