Biomedical subjects
Publications and source records attributed to E Jennings.
A novel and in situ technique is presented here as a better alternative to culture-dependent and PCR-based techniques for the quantitative detection of predominant bacterial species involved in the bioremediation of contaminants. It allowed rapid, specific and in situ identification of Biosep-immobilized eubacteria from MTBE- and benzene-contaminated matrices.
Intranasal schwannomas are rare lesions, specially when they present with an intracranial extension. The fifth case in the medical literature of a naso-ethmoid schwannoma with extension into the anterior cranial fossa is presented. The magnetic resonance findings and the details of the combined intracranial / transfacial operative approach used are described. The possible origin and the clinical characteristics of this rare lesion are reviewed.
The Reitan-Indiana Neuropsychological Battery (RINB) was administered to a sample of children referred for educational and behavioral problems (N = 130). Subtest scores were standardized by age at 1-year intervals (6, 7, and 8 years). A principal components analysis (PCA) with promax rotation of 18 subtest scores produced a five-factor solution. Factor 1 emphasizes tactile/spatial functions, Factor 2 emphasizes concept formation and visual/spatial abilities, Factor 3 reflects motor strength, Factor 4 emphasizes sensory perception, and Factor 5 reflects motor speed. Principal factor analysis (PFA) of these data was performed to permit comparison with the PCA solutions. The PFA and PCA solutions were similar and major conclusions about factor structure were consistent.
The mechanisms by which infants and children process pain should be viewed within the context of a developing sensory nervous system. The study of the neurophysiological properties and connectivity of sensory neurons in the developing spinal cord dorsal horn of the intact postnatal rat has shed light on the way in which the newborn central nervous system analyzes cutaneous innocuous and noxious stimuli. The receptive field properties and evoked activity of newborn dorsal horn cells to single repetitive and persistent innocuous and noxious inputs are developmentally regulated and reflect the maturation of excitatory transmission within the spinal cord. These changes will have an important influence on pain processing in the postnatal period.
Butyrivibrio fibrisolvens strains D1 and A38 produced little lactate, but strain 49 converted as much as 75% of its glucose to lactate. Strain 49 had tenfold more lactate dehydrogenase activity than strains D1 or A38, this activity was stimulated by fructose 1,6-bisphosphate, and had a pH optimum of 6.25. A role for fructose 1,6-bisphosphate or pH regulation of lactate production in strain 49 was, however, contradicted by the observations that very low concentrations (< 0.2 mM) of fructose 1,6-bisphosphate gave maximal activity, and continuous cultures did not produce additional lactate when the pH was decreased. The lactate production of strain 49 was clearly inhibited by the presence of acetate in the growth medium. When strain 49 was supplemented with as little as 5 mM acetate, lactate production decreased dramatically, and most of the glucose was converted to butyrate. Strain 49 did not possess butyrate kinase activity, but it had a butyryl-CoA/acetate CoA transferase that converted butyryl-CoA directly to butyrate, using acetate as an acceptor. The transferase had a low affinity for acetate (K(m) of 5 mM), and this characteristic explained the acetate stimulation of growth and butyrate formation. Strains D1 and A38 had butyrate kinase but not butyryl-CoA/acetate CoA transferase, and it appeared that this difference could explain the lack of acetate stimulation and lactate production. Based on these results, it is unlikely that B. fibrisolvens would ever contribute significantly to the pool of ruminal lactate. Since relatives of strain 49 (strains Nor37, PI-7, VV1, and OB156, based on 16S rRNA sequence analysis) all had the same method of butyrate production, it appeared that butyryl-CoA/acetate CoA transferase might be a phylogenetic characteristic. We obtained a culture of strain B835 (NCDO 2398) that produced large amounts of lactate and had butyryl-CoA/acetate CoA transferase activity, but this strain had previously been grouped with strains A38 and D1 based on 16S rRNA sequence analysis. Our strain B835 had a 16S rRNA sequence unique from the one currently deposited in GenBank, and had high sequence similarity with strains 49 and Nor37 rather than with strains A38 or D1.
A remote site in the Tallgrass Prairie Preserve (Osage County, OK) was contaminated with crude oil by a pipeline break in 1992. In 1996, the contaminated soil was bioremediated by blending with uncontaminated soil, prairie hay, buffalo manure, and commercial fertilizers, and spreading in a shallow layer over uncontaminated soil to create a landfarm. The landfarm was monitored for two years for aerobic and anaerobic bacteria, soil gases indicative of microbial activity, and for changes in the concentration of total petroleum hydrocarbons (TPH). Levels of hydrocarbon degraders and soil gas indicators of aerobic degradation were stimulated in the landfarm during the first warm season relative to uncontaminated prairie soil. However, these same indicators were less conclusive during the second warm season, indicating depletion of the more easily degradable hydrocarbons, although the landfarm still contained 6,800 mg/kg TPH on the average at the beginning of the second warm season. Methane formation and methanogen counts were clearly stimulated in the first warm season relative to uncontaminated prairie soil, indicating that methanogenesis plays an important role in the mineralization of hydrocarbons even in these shallow soils.
Successful deployment of a bioethanol process depends on the integration of technologies that can be economically commercialized. Pretreatment and fermentation operations of the traditional enzymatic bioethanol-production process constitute the largest portion of the capital and operating costs. Cost reduction in these areas, through improved reactions and reduced capital, will improve the economic feasibility of a large-scale plant. A technoeconomic model was developed using the ASPEN Plus modeling software package. This model included a two-stage pretreatment operation with a co-current first stage and countercurrent second stage, a lignin adsorption unit, and a cofermentation unit. Data from kinetic modeling of the pretreatment reactions, verified by bench-scale experiments, were used to create the ASPEN Plus base model. Results from the initial pretreatment and fermentation yields of the two-stage system correlated well to the performance targets established by the model. The ASPEN Plus model determined mass and energy-balance information, which was supplied to an economic module to determine the required selling price of the ethanol. Several pretreatment process variables such as glucose yield, liquid: solid ratio, additional pretreatment stages, and lignin adsorption were varied to determine which parameters had the greatest effect on the process economics. Optimized values for these key variables became target values for the bench-scale research, either to achieve or identify as potential obstacles in the future commercialization process. Results from this modeling and experimentation sequence have led to the design of an advanced two-stage engineering- scale reactor for a dilute-acid hydrolysis process.
The development of diffuse noxious inhibitory controls (DNIC) was studied in postnatal rats aged 12, 21 and 42-days-old, using immunoreactive localization of the c-fos protein products induced in the dorsal horn by noxious stimulation. The presence of DNIC was revealed by the reduction in the levels of Fos-like immunoreactivity that are normally induced by a standardized primary pinch stimulus when this stimulus was accompanied by a concurrent noxious stimulus (formalin) to a heterotopic body part. Significant reductions were seen at postnatal day 42 (P42; 15% reduction) and P21 (17% reduction), but concurrent stimulation had no significant effect at P12. These results suggest that the system subserving DNIC is functionally mature by P21, but not effective at P12. This delayed maturation of an inhibitory system may underlie the extreme sensitivity to somatosensory stimulation seen in neonatal pups and premature infants.
1. In vivo extracellular recordings were made of 171 dorsal horn cells in both superficial and deep laminae in urethane-anaesthetized newborn rats aged 3, 6, 10 and 21 days, and their response to single and repeated stimuli to primary afferent fibres investigated. 2. No long-latency spike responses were evoked in response to C fibre stimulation in pups at postnatal day 3 (P3) or P6, while by P10, 35 % of cells had a C fibre response. Latencies of response to A fibre skin stimulation were very long and varied widely in the youngest animals, particularly in superficial cells, but mean latencies decreased with postnatal age, from 33.1 +/- 2.78 ms at P3 to 7.3 +/- 0.3 ms at P21. The mean number of spikes evoked by a single A fibre skin stimulus was remarkably consistent between cells and not significantly different in superficial and deep laminae at each age. The mean value of 5.1 +/- 0.6 at P3 increased to 7.0 +/- 1.4 at P10. 3. Repeated stimulation of cutaneous A fibres at 0.5 Hz at twice the threshold level did not significantly alter the magnitude of the evoked response but led to shifts in latency, or 'latency jitter', which decreased with age. Deeper cells displayed more latency jitter than superficial cells. 4. Repeated stimulation of cutaneous A fibres at 0.5 Hz at twice the threshold level produced considerable sensitization in a population of dorsal horn cells in the neonate. This sensitization was unlike the classic C fibre-evoked 'wind-up' observed in adult dorsal horn. The direct A fibre-evoked activity did not increase, but the background activity increased during repetitive stimulation leading to a prolonged after-discharge beyond the stimulation period. At P6, 33 % of cells were sensitized, displaying a mean after-discharge of 70.6 +/- 18 s. At P10, only 6 % were sensitized, with a mean after-discharge of 63 s, and by P21, sensitization was no longer observed. 5. The present study demonstrates that the postsynaptic activity evoked in neonatal dorsal horn cells by cutaneous afferents differs considerably from that in adults. The results may account for the known behavioural reflex sensitization to low-intensity cutaneous stimulation observed in neonatal rats and man.
The development of spinal cord nociceptive pathways has been investigated in neonatal rat pups using the expression of Fos immunoreactivity in laminae I and II cells produced by high and low intensity skin stimulation. Noxious pinch of the hindpaw evoked a clear response in the newborn rat pup, which was not significantly different from that seen at postnatal day (P) 21. Low intensity touch stimulation also produced a significant fos response in laminae I and II cells at P3 which was 60% that of the pinch response. This was reduced to 27% of the pinch response by P10 and was gone by P21. Electrical stimulation through percutaneous electrodes showed that A beta fibre stimulation also produced a fos response at P3 that was not significantly different from that produced by C fibre stimulation. By P21 and P30 the response to C fibre stimulation was much greater and the response to A fibre stimulation was not significantly above background. The results suggest that in the neonatal spinal cord, low threshold A fibres are able to activate pathways in lamina I and II of the dorsal horn that in the adult are predominantly nociceptive.
YY1 is ubiquitously expressed zinc finger DNA binding protein. It can act as a transcriptional repressor or activator and, when binding at the initiator element, as a component of the basal transcription complex. Binding sites for YY1 have been reported in a wide variety of promoters and they exhibit substantial diversity in their sequence. To better understand how YY1 interacts with DNA and to be able to predict the presence of YY1 sites in a more comprehensive fashion, we have selected YY1 binding sites from a random pool of oligonucleotides. The sites display considerable heterogeneity, but contain a conserved 5'-CAT-3' core flanked by variable regions, generating the consensus 5'-(C/g/a)(G/t)(C/t/a)CATN(T/a)(T/g/c)-3', where the upper case letters represent the preferred base. This high degree of flexibility in DNA recognition can be predicted by modeling the interaction of the four YY1 zinc fingers with DNA and a detailed model for this interaction is presented and discussed.
Higher intakes of folic acid-rich foods such as vegetables, legumes, and whole grains are associated with lower incidence of carcinomas in international comparisons and case-control studies. Deficiency of folic acid in experimental studies causes DNA damage that resembles the DNA damage seen in cancer cells. The requirement for folic acid in DNA synthesis and DNA methylation provides a plausible mechanism for a mutagenic effect of a low-folate diet. It is suggested that cancer can be initiated by DNA damage that results from folic acid deficiency. The relatively low level of folic acid in North American diets might be the underlying reason for high rates of many cancers in North America.
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Computerized tomography (CT) was used in the evaluation or follow-up of 89 patients with malignant tumors. Excellent correlation was found between the preoperative CT findings and those at surgical resection of the tumor in 52 patients. Ct scan was the only test demonstrating the tumor mass in 18% and was superior to other tests in 67% of patients. When used as a follow-up test to detect recurrence in 74 patients, it was the first test to reveal recurrence in 30.5% of 36 patients who developed recurrence. It was false negative in one patient, and gave rise to false positive interpretations in seven patients. Overall, the CT scan was superior to conventional radiologic techniques, but the latter are not replaced completely and remain essential in the pertinent anatomical situations.
A survey of 509 family physicians in New York State was conducted to assess opinions about mammography and use of mammography in screening asymptomatic women of different ages. Findings indicate that most family physicians believe that mammography is an effective procedure for detecting breast cancer in its early stages, but many do not utilize mammography as a screening procedure in their own practices. The major deterrents to the use of mammography in screening asymptomatic women relate to concerns about the safety and reliability of the procedure, the low probability of detecting breast cancer through screening, the patient's willingness to accept a recommendation to have a mammogram, and cost. The results from this study point out the need to better educate primary care physicians about the use of mammography in screening for breast cancer, especially in regard to its safety and reliability.
Thirty-one patients with metastatic brain tumors (MBT) from lung cancer and ten patients with MBT from melanoma received BCNU, 100 mg/m2, every four weeks by intracarotid and/or vertebral artery infusion into each involved site. Twenty-five patients with lung cancer and all melanoma patients are currently evaluable. Twelve patients with lung cancer had complete and partial responses lasting from 1 to 14 months. Four of them with the histologic diagnosis of small cell carcinoma, one with large cell carcinoma and one with squamous cell carcinoma showed complete response. None of the patients with melanoma MBT experienced any response. All of the patients had periorbital erythralgia and/or occipital pain during the infusion. Four patients manifested mild focal seizures during the infusion or 6 to 24 hours after the treatment. Transient confusion with disorientation was observed in two patients 4 and 24 hours, respectively, after a BCNU infusion. Two patients developed reversible thrombocytopenia after the fifth course of the IA chemotherapy. Median survival of patients with MBT from lung carcinoma was 4 months, with two of them still alive at 10 and 14 months, respectively. Only one patients of the 25 with lung carcinoma died from MBT. Failure to control the primary disease resulted in the deaths of a vast majority of the patients.
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Twenty-eight adult patients with nonirradiated malignant gliomas of the brain were administered a combination of methyl-CCNU (130 mg/m2, p.o., day 1), vincristine (2 mg/m2, i.v., day 1) and procarbazine (100 mg/m2, p.o., days 2 to 15) (MVP), scheduled to be given at successive 6 week intervals. Nineteen (67.9%) were not responsive to MVP and 9 (32.1%) were. Of 16 who had previous partial resection of their tumors, 8 (50%) responded to MVP and 8 (50%) did not. Of 12 who had previous biopsy, only 1 (8.3%) responded. Overall 1-year survival rate for the 28 patients was 28.6%. Major side effects of MVP were leukopenia, thrombocytopenia, pulmonary emboli, and thrombophlebitis, detected mainly during the first 20 to 24 weeks of treatment.