CEREBRAL COMPLICATIONS INCURRED DURING PREGNANCY AND THE PUERPERIUM

In a statistical study of maternal mortality cases in Franklin County, Ohio, with a total of 170 deaths in a ten-year period (1948-1957), there were 36 fatal cases with cerebral complications of various types. Intracranial hemorrhage was the cause of death in 17 cases; subarachnoid hemorrhage in eight; intracerebral hemorrhage in eight and subdural hemorrhage in one case. There were nine cases of intracranial tumor with fatality. In a miscellaneous group of ten “cerebral deaths” infectious processes were the cause in eight cases, including tuberculous meningitis, purulent meningitis, brain abscess, acute (cerebromedullary) poliomyelitis, “viral” encephalitis, toxoplasmosis and tetanus.In a smaller clinical (nonfatal) group with cerebral complications occurring during pregnancy and the puerperium, two patients with subarachnoid hemorrhages made spontaneous recovery. A diagnosis of intracerebral hemorrhage was made in three instances, in two of which operation was done and evacuation of blood clots was accomplished. One patient recovered spontaneously from a minimal hemorrhage.Five other persons had cerebral thrombosis, three in the third month of pregnancy and two in the immediate puerperium. All recovered, with some residual deficits.Three patients with intracranial tumor were successfully treated surgically but with disappointing results ultimately (one case each of cerebellar medulloblastoma, cerebral astrocytoma and supratentorial meningioma).Only when the obstetrician, neurologist and the neurosurgeon are fully aware of the signs, symptoms, and many times the rapid course of these cerebral complications of pregnancy, can there be any material lowering of the morbidity and mortality. Emphasis should be placed on the early investigation of all neurological complaints during pregnancy and the puerperium, with immediate institution of an aggressive diagnostic and therapeutic regimen.     

Comparison of α1-Adrenergic Receptor-Stimulated Inositol Phosphate Formation in Primary Neuronal and Glial Cultures

alpha 1-Adrenergic receptor binding sites and norepinephrine-stimulated 3H-inositol phosphate (3H-InsP) accumulation were measured in primary cultures of neurons and glia from 1-day-old rat brains. The density of alpha 1-adrenergic receptor binding sites was approximately three times higher in membranes from neurons compared to glia. Although norepinephrine was slightly more potent in stimulating 3H-InsP formation in neurons than in glia, the maximal response was greater in glial cells. Norepinephrine-stimulated 3H-InsP formation remained constant for [3H]inositol prelabelling periods of 1-14 days in neurons, whereas the response increased with time in glia and was maximal after 7-10 days of prelabelling. Both the incorporation of [3H]inositol into lipid and basal levels of 3H-InsPs were lower in glial cells than in neurons, which accounted for the greater percent stimulation in glia. Pretreatment with phenoxybenzamine decreased norepinephrine-stimulated 3H-InsP formation in a dose-dependent manner in both neurons and glia by decreasing the maximal response without altering potency. HPLC separation showed that similar types of 3H-InsPs were accumulated in neurons and glial cells. These results demonstrate that alpha 1-adrenergic receptors exist on both neurons and glial cells and activate 3H-InsP accumulation in both cell types. Although receptor density is higher in neurons than in glia, the 3H-InsP response is higher in glia. This difference does not appear to be due to different receptor reserves, but may be due to differential coupling mechanisms in the two cell types.     

Rates of synonymous substitution in plant nuclear genes

Summary The rate of synonymous nucleotide substitution in nuclear genes of higher plants has been estimated. The rate varies among genes by a factor of up to two, in a manner that is not immediately explicable in terms of base composition or codon usage bias. The average rate, in both monocots and dicots, is about four times higher than that in chloroplast genes. This leads to an estimated absolute silent substitution rate of 6 × 10^–9 substitutions per site per year that falls within the range of average rates (2–8 × 10^–9) seen in different mammalian nuclear genomes.     

A Direct Screening Procedure for Gravitropism Mutants in Arabidopsis thaliana (L.) Heynh.

In order to isolate gravitropism mutants of Arabidopsis thaliana (L.) Heynh. var Estland for the genetic dissection of the gravitropism pathway, a direct screening procedure has been developed in which mutants are selected on the basis of their gravitropic response. Variability in hypocotyl curvature was dependent on the germination time of each seed stock, resulting in the incorrect identification of several lines as gravitropism mutants when a standard protocol for the potentiation of germination was used. When the protocol was adjusted to allow for differences in germination time, these lines were eliminated from the collection. Out of the 60,000 M2 seedlings screened, 0.3 to 0.4% exhibited altered gravitropism. In approximately 40% of these mutant lines, only gravitropism by the root or the hypocotyl was altered, while the response of the other organ was unaffected. These data support the hypothesis that root and hypocotyl gravitropism are genetically separable.     

Parametric study of diethyl phthalate biodegradation

Summary The effects of temperature, dissolved oxygen, and other environmental parameters under both aerobic and anaerobic conditions were investigated using one aerobic and one facultative strain isolated from wastewater treatment plant sludge. Among other results, we found that low dissolved oxygen levels and low temperatures decreased the rate of DEP degradation and the growth rate, and that the facultative strain was much less affected by the lower DO concentrations than the aerobic strain.