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Biomedical subjects

J M Graham

Publications and source records attributed to J M Graham.

At least 217 records · Page 12Linked to original sources
PubMed1984

A comparison of intravenous and intramuscular magnesium sulfate regimens in preeclampsia.

A prospective study comparing continuous intravenous magnesium sulfate to intramuscular magnesium sulfate was performed in 32 preeclamptic patients. Eighteen patients received the intramuscular regimen for mild and severe preeclampsia as recommended by Pritchard. The remaining 14 patients received an intravenous regimen consisting of a 4 gm loading dose administered over 15 minutes followed by a maintenance dose of either 1 gm/hr (n = 7) or 2 gm/hr (n = 7). All groups were similar regarding maternal age, height, weight, fetal gestational age, and laboratory findings. The intravenous regimen with a maintenance dose of 1 gm/hr produced serum magnesium levels that were much lower than those achieved with the intramuscular regimen. There was no significant difference after 3 hours of therapy between the mean magnesium levels achieved with the intramuscular regimen and the levels achieved with the intravenous regimen with a maintenance dose of 2 gm/hr. However, during the first 3 hours of therapy the intramuscular regimen for severe preeclampsia produced mean magnesium levels that were significantly higher than those levels obtained with the intravenous regimen with a maintenance dose of 2 gm/hr (p less than 0.001). Both methods were safe. However, the intravenous regimen with a maintenance dose of 1 gm/hr is inadequate in management of preeclamptic patients.

Adolescent↗
PubMed1984

Localization of vasopressin in synaptic vesicles of extra-hypothalamic rat brain.

The subcellular localization of vasopressin (VP) from extra-hypothalamic areas of rat brain was investigated by measuring its distribution (a) along a continuous sucrose gradient; (b) during the preparation of isolated nerve endings (synaptosomes) and (c) during the preparation of synaptic vesicles. Quite large amounts of vasopressin are isolated in the same fractions as mitochondria, as well as synaptosomes. Osmotic rupture of membrane bound organelles in the homogenate results in the vasopressin being measured largely in the fraction containing synaptic vesicles. These results would suggest that vasopressin could be released by nerve terminals which is consistent with the hypothesis that it may have a neurotransmitter/neuromodulator function in the CNS.

Animals↗
PubMed1984

Enhanced visualization of soft tissues in the study of aborted fetuses through the use of xeroradiography.

As part of the diagnostic workup following an episode of fetal loss, it is generally recommended that fetal tissue be submitted for chromosome analysis and that the fetus be photographed and radiographed. Our recent clinical experience has suggested that, in those fetuses where size is compatible, xeroradiography may be superior to standard radiography. Xeroradiography utilizes principles similar to those in film radiology, with low-energy photon beams and relatively long exposure times. The physical characteristics of the beam and imaging system provide optimal soft tissue visualization. We have found this technique to be of use in studying a broad variety of abortuses with abnormalities. Examples of fetal abnormalities in which we have used this technique include acardia, neural tube defects, nuchal cystic hygroma, and arthrogryposis. In fetuses weighing 500-1,000 gm, the exposure settings are 25 MA, 1 second, 40 KVP. For larger fetuses the KVP should be increased by 1 or 2. This technique has not been useful for a complete body view of large fetuses due to the size limitations of the xeroradiographic cassette itself.

Anencephaly↗
PubMed1984

Clinical monitoring of the effects of gentamicin by electrocochleography.

Eight patients receiving prolonged treatment with gentamicin for bacterial endocarditis were monitored for possible ototoxicity using transtympanic electrocochleography as an adjunct to pure tone audiometry, vestibular function tests and serum gentamicin levels. An immediate effect of intravenous gentamicin on the cochlea, shown by changes in the whole nerve action potential and/or cochlear microphonic was recorded in seven patients, none of whom had experienced vestibular or auditory symptoms with gentamicin prior to testing. Two patients subsequently developed evidence of vestibular dysfunction, and a high frequency sensorineural hearing loss occurred in a third individual. There have been no previous report of the immediate effects of gentamicin on the human cochlea to date. The significance of these findings in routine clinical monitoring of ototoxicity is discussed in the light of clinical and animal evidence for the possible mode of action of aminoglycosides on the auditory and vestibular apparatus.

Action Potentials↗
PubMed1984

Congenital hydranencephaly/porencephaly due to vascular disruption in monozygotic twins.

Monozygotic twinning has been associated with a variety of vascular disruptive defects including congenital hydranencephaly/porencephaly. Data involving 24 cases of congenital hydranencephaly/porencephaly associated with twinning are reported. In these cases, the finding of a preponderance of monozygotic twins and the common association of a deceased co-twin support the hypothesis of a vascular disruptive etiology. These defects are presumed to be secondary to embolic phenomena or thromboplastin release from the deceased co-twin to the survivor via the vascular interconnections of a conjoined monochorionic placenta. In all cases of hydranencephaly/porencephaly, a careful examination of the placenta and membranes for evidence of a deceased co-twin is warranted prior to providing recurrence risk counseling.

Anencephaly↗
PubMed1983

Jejunal atresia associated with Cafergot ingestion during pregnancy.

Fetal vascular accidents have been suggested as one cause for jejunal atresia due to in utero interruption of the superior mesenteric arterial supply to the intestines. Experimental studies support this hypothesis, and ergotamine has been shown to be a teratogen in experimental animals as a consequence of its vasoconstrictive action. We report the occurrence of intrauterine growth retardation and jejunal atresia in an offspring of a woman who also experienced four spontaneous abortions. During each of six pregnancies, the mother had taken as many as eight Cafergot tablets daily. We raise the hypothesis that Cafergot (1 mg ergotamine tartrate and 100 mg caffeine) might represent a vascular disruptive teratogenic agent during pregnancy. This hypothesis is supported by the clinical association of nonduodenal intestinal atresia with other defects that have a disruptive vascular etiology.

Abnormalities, Drug-Induced↗