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Biomedical subjects

J Whitehall

Publications and source records attributed to J Whitehall.

34 records · Page 2Linked to original sources
PubMed1999

Gestational magnesium deficiency is deleterious to fetal outcome.

A number of recent epidemiological findings have implicated magnesium as being essential to fetal well-being. Few studies, however, have examined the relationship between maternal requirements for dietary magnesium and subsequent mortality and morbidity in offspring. The present study uses a rodent model of dietary-induced hypomagnesemia to investigate the effects of magnesium deficiency prior to and during gestation on neonatal morbidity and mortality. Magnesium deficiency during gestation significantly increased neonatal mortality and morbidity. Such increases were associated with a reduced free magnesium concentration in both maternal and offspring blood and an increased incidence of periventricular hemorrhage and edema in newborn pups as observed by magnetic resonance imaging and histology. Animals fed a magnesium-deficient diet before mating but given magnesium supplementation during gestation did not demonstrate a significant change in neonatal mortality and morbidity when compared to control animals. The significant improvement in fetal outcome with dietary magnesium supports the concept of magnesium supplementation during pregnancy.

Animals↗
PubMed1999

Minimum requirements for remote realtime fetal tele-ultrasound consultation.

We studied the transmission bandwidth required for accurate diagnoses when performing realtime fetal tele-ultrasound consultations. The study was divided into three phases. In phase I, three experienced clinicians evaluated the quality of ultrasound images transmitted at various bandwidths (internally looped back within Brisbane) using eight commercially available codecs at random. The two codecs that performed best proceeded to phase 2, in which a realtime video-link of up to 2 Mbit/s was set up between Brisbane and Townsville (1,500 km apart). Testing with a standard video-tape was performed at seven different bandwidths selected at random, with four clinicians (who were blinded to the equipment and bandwidths used). The optimum line rates for transmission were determined, and testing was then performed using these line rates for fetuses with various anomalies (phase 3). The results showed significant differences in performance according to bandwidths used, but not according to observers. Bandwidths were grouped into three levels. At level I (256 kbit/s) the performance was significantly worse than at level II (384, 512 or 768 kbit/s), which was in turn worse than that at level III (1, 1.5 or 2 Mbit/s). However, within each level, performance at one bandwidth was not significantly different from that at the others. The most cost-effective transmission rates therefore appeared to be 384 kbit/s and 1 Mbit/s. Further testing with fetuses affected by various anomalies confirmed that the majority could be diagnosed using a 384 kbit/s link, with slight improvement in evaluation when the bandwidth was increased to 1 Mbit/s.

Analysis of Variance↗
PubMed1998

Meconium thorax: a case report and review of literature.

A case is presented in which extension of meconium peritonitis through muscular defects in the diaphragm lead to intrathoracic calcifications diagnosed sonographically at 23 weeks of gestation. There were three diaphragmatic defects, two small ones corresponded to foramina of Morgagni and one large posterior defect that did not correspond to the foramen of Bochdelak. There were three additional muscular defects: one in the rectus abdominus and two, bilaterally, in the loins. Despite long-standing fetal ascites and fresh intraperitoneal meconium at laparotomy, postoperative progress was uneventful. The baby did not have other dysmorphic features except for a single palmar crease, the chromosomes were normal, and the baby did not have cystic fibrosis. Follow-up examination at 10 months showed a thriving infant with mild hypotonia and developmental delay, but no respiratory or gastrointestinal problems.

Adult↗
PubMed1998

Telemedicine in neonatology: lessons from North Queensland.

Using videoconferencing technology, educational programs in neonatology were provided for staff at rural hospitals. The technology was also used to reunite babies with their families and its usefulness in long-distance diagnosis was assessed. Eighty-two educational sessions were delivered over a 9 month period and, despite problems with technology, operation and presentation, were considered worthwhile by the audiences. Family reunions were very successful. Neonatal diagnosis was impossible at the narrow bandwidth used (128 kilobits/s). Valuable lessons were learned regarding optimum use of this medium.

Education, Medical, Continuing↗
PubMed1998

Improved oxygenation following adenosine infusion in persistent pulmonary hypertension of the newborn.

Six consecutive cases of persistent pulmonary hypertension of the newborn (PPHN) were treated with adenosine following failure of conventional therapy, excluding inhaled nitric oxide. A rise in arterial PO2 >20 mm Hg occurred in 5 of 6 cases within 30 min of commencing adenosine infusion. Individual maximal increases in PaO2 ranged from 31 to 131 mm Hg. Three neonates survived and 3 died. Amongst deaths, intensive support was withdrawn in a preterm neonate due to severe arthrogryposis/pulmonary hypoplasia. Of the remaining 2, the improvement in oxygenation persisted until death occurred from causes unrelated to adenosine. Side effects related to adenosine (bradycardia, hypotension, prolonged bleeding time) did not occur. Due to its ease of availability, administration and extremely short half-life, adenosine may be an important therapeutic option in PPHN.

Adenosine↗
PubMed1995

A novel method for isolating and quantifying urine pathogens collected from gel-based diapers.

BACKGROUND: Given that children often present to physicians with a wet gel-based diaper, a method for using this diaper for a urine specimen was studied. METHODS: A blinded clinical laboratory trial was conducted in the microbiology laboratory. The sampling technique involved the use of oval gynecologic forceps as a template and sterile scissors to cut out samples of diapers. Each diaper sample was then vortexed in 20 mL of sterile saline and the supernatant quantitatively cultured. Diaper sample supernatant cultures with simulated infected urines (suspensions of Escherichia coli) were used. RESULTS: Weight measurements of the diaper samples soaked with 20 mL or more of saline yielded reproducible results (0.703 g; 95% confidence interval [CI], 0.52 to 0.88 g). Culture results (colony-forming units per liter [CFU/L] of supernatant) from diapers soaked with 25 mL of various concentrations of E coli (10(6), 10(7), 10(8), 10(9) CFU/L) showed excellent correlation with the inoculum used, and no effect of a 2-hour delay in culturing the wet diapers. CONCLUSIONS: Our technique provides accurate and reliable estimates of bacterial concentrations in the usual range for infected urine from gel-based diapers soaked with solutions of E coli. Further evaluation of clinical implementation is needed.

Escherichia coli↗