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Biomedical subjects

B Bowman

Publications and source records attributed to B Bowman.

At least 37 records · Page 2Linked to original sources
PubMed1995

The effect of electrical stimulation on obstructive sleep apnea syndrome.

Patients with severe obstructive sleep apnea polygraphically documented underwent electrical stimulation treatment trials. Submental and intraoral stimulations were applied during waking and during nocturnal sleep. The stimulation was applied using a custom-designed neuromuscular electrical stimulator (EdenTec Corp) providing symmetric biphasic constant voltage pulses. Pulse duration of each phase was set to 80 microseconds based on a subjective evaluation of pulse durations from 80 to 300 microseconds to minimize sensation while generating equivalent motor responses. Pulse repetition rate was set to 50 pulses per second. Cephalometric radiographs and endoscopies were obtained with and without stimulations during waking. Most commonly, stimulations induced alpha EEG arousals. Submental subcutaneous stimulation induced good contractions of platysmal muscles but had no impact on the upper airway. Intraoral stimulation induced clear tongue muscle movements but with change of shape of the upper airway and posterior movements of the tongue. Each time a breakage of apnea was noted, it was associated with a time-linked alpha EEG arousal. The results obtained by us and others do not, at this time, give convincing support for the use of electrical stimulation using submental surface or intraoral electrodes as a viable approach for effective control of obstructive sleep apnea syndrome symptoms.

Electric Stimulation Therapy↗
PubMed1993

Vitamin E supplements and coronary heart disease.

Although two new epidemiologic studies on the association between vitamin E and heart disease do not resolve important issues related to dose-response, mechanisms of action, or specificity, they do provide important evidence that supports the development of new strategies for preventing heart disease.

Adult↗
PubMed1993

Pre-operative staging of colorectal carcinoma using positron emission tomography.

Positron emission tomography (PET) is a unique technique for imaging functional metabolism of normal and diseased tissue. Accelerated rate of glucose metabolism typical of malignant tumor cells can be detected by using fluorine-18 deoxyglucose. In this pilot study, PET FDG imaging was compared to computerized tomography for the pre-operative staging of colorectal carcinoma. We prospectively evaluated 16 patients by simultaneously performing PET FDG and CT imaging for lesions in the liver, colon and rectum. The results were compared to the operative findings in all patients. Twenty tumor sites (lymph nodes 5, colon and rectum 13, liver 2) were found on histology in 16 patients. On comparison with histology, sensitivity, specificity and predictive accuracy for detection of tumor sites were 90%, 66% and 87% with PET as compared to 60%, 100%, and 65% with CT. These findings represent increased sensitivity and predictive accuracy for staging of colorectal carcinoma with PET FDG imaging as compared to CT scanning.

Aged↗
PubMed1992

Characterization of the ilv-2 gene from Neurospora crassa encoding alpha-keto-beta-hydroxylacyl reductoisomerase.

We have isolated the cDNA and corresponding genomic DNA for the ilv-2 locus of Neurospora crassa. This gene encodes alpha-keto-beta-hydroxylacyl reductoisomerase (Ilv-2), required for the synthesis of isoleucine and valine. The gene contains four introns, maps to the right arm of chromosome V, and encodes a protein of 400 amino acids (aa). Alignment of the aa sequence of Ilv-2 with the two other known eukaryotic sequences encoding this enzyme reveals two conserved regions.

2-Acetolactate Mutase↗
PubMed1992

The pigtail probe protected by silicone intubation: a combined approach to canalicular reconstruction.

We have devised a method of single-eyelid canalicular reconstruction using the pigtail probe to facilitate identification of the proximal canalicular segment following silicone stent intubation of the normal, uninjured canaliculus. A series of seven acute and two long-standing canalicular lacerations were successfully reconstructed using this technique, which minimizes the risks associated with the use of the pigtail probe.

Eye Injuries↗
PubMed1987

Altered fractional excretion of uric acid during total parenteral nutrition.

The presence of crystal proven podagra coincident with a 52% decrease in plasma urate after a 3-day course of total parenteral nutrition (TPN) prompted a study of urate excretion in 9 patients with Crohn's disease. By Day 9 in those receiving TPN, plasma urate decreased 58% (p less than 0.001), while fractional urate excretion increased 94% (p less than 0.005). Twenty-four hour urate excretion and serum creatinine were not significantly altered. These findings persisted for the duration of TPN. In 2 patients with ileocolitis, the addition or deletion of either lipid emulsion or multivitamin infusions during TPN had no effect on urate values. Rather, the amino acid load or a specific constituent appears to be the causal factor. These data suggest that hypouricemia due to extensive net urate excretion is common during TPN therapy. Finally, patients with established gout may be at risk for acute gouty attacks during TPN therapy.

Adult↗
PubMed1983

Effects of feedback stimulation training and cyclical electrical stimulation on knee extension in hemiparetic patients.

Positional feedback stimulation training and cyclical electrical stimulation were used in combination as a treatment for facilitating knee extension in hemiparetic patients. Forty adult hemiparetic patients who demonstrated minimal active control of their quadriceps femoris muscles were randomly assigned to control or study groups. The control patients received a program of physical therapy, and the study patients received the positional feedback stimulation training in addition to their therapy program. The stimulation training provided the patient with immediate auditory and visual feedback of his changing joint angle while he voluntarily extended his knee. When the patient reached a near maximal extension effort, electrical stimulation of the quadriceps femoris muscle was automatically triggered, completing the patient's available range of motion in extension. The stimulation training was supplemented with two hours of cyclical electrical stimulation daily. At the end of four weeks, analysis revealed a statistically significant increase in knee extension torque and active synergistic range of motion in the study group. No change was noted in their ability to extend their knees using isolated quadriceps femoris muscle control. This study suggests that positional feedback stimulation training is effective when used to augment a facilitation program for improving knee extension control in hemiparetic patients.

Adult↗
PubMed1982

Testing and modelling of spasticity.

The aim of this investigation was to develop a clinically applicable method for quantitative evaluation of spasticity about the knee and to determine the minimum instrumentation necessary for a quick and simple estimation of spasticity. Skeletal muscle spasticity is assessed by physical therapists as increased resistance of a particular muscle group to manually induced passive movement. In this study the passive movement was produced by the force of gravity while the resistance was observed from the joint goniogram. Spasticity of the knee extensors was measured on patients with spinal cord injuries. Records of severe, moderate, and slight spasticity are presented in the paper. A mathematical model has been developed describing the behaviour of healthy and spastic extremity.

Electromyography↗
PubMedDate not supplied

Physiologic motion phantom for MRI applications.

To address the need for a complex physiologic motion phantom for use in MR applications, such as the verification of techniques for measuring myocardial motion dynamics and motion insensitive pulse sequences, a computer-controlled motion phantom has been designed. The phantom, which consists of a deformable silicone gel annulus mounted on a translation stage, can undergo a range of bulk motions and deformations. Available motions include bulk rotation and translation, rotational shear, axial shear, and combinations of some or all of these motions. In this paper, the capability of the phantom to produce accurate constant and time-varying waveforms is demonstrated. In the current implementation, peak linear translation and rotation rates are 175 mm s-1 and 10 rad s-1, respectively. Cycle-to-cycle reproducibility is excellent, with variations of less than .003 radians over the period of hours while undergoing rotational shear. The phantom has been designed in a flexible fashion so that various test objects can be scanned while undergoing bulk translation and can be adapted to produce different deformations.

Hemodynamics↗
PubMedDate not supplied

DNA sequences from the quagga, an extinct member of the horse family.

To determine whether DNA survives and can be recovered from the remains of extinct creatures, we have examined dried muscle from a museum specimen of the quagga, a zebra-like species (Equus quagga) that became extinct in 1883 (ref. 1). We report that DNA was extracted from this tissue in amounts approaching 1% of that expected from fresh muscle, and that the DNA was of relatively low molecular weight. Among the many clones obtained from the quagga DNA, two containing pieces of mitochondrial DNA (mtDNA) were sequenced. These sequences, comprising 229 nucleotide pairs, differ by 12 base substitutions from the corresponding sequences of mtDNA from a mountain zebra, an extant member of the genus Equus. The number, nature and locations of the substitutions imply that there has been little or no postmortem modification of the quagga DNA sequences, and that the two species had a common ancestor 3-4 Myr ago, consistent with fossil evidence concerning the age of the genus Equus.

Animals↗
PubMedDate not supplied

The 1997 Lindberg Award. Effects of burn injury on bone and growth in a mouse model.

Bone growth and remodeling are inhibited by severe burns in adult and pediatric patients, resulting in alterations in linear growth, bone mass, osteoporosis, and increased risk for pathologic fractures. This study of a mouse model of burn injury showed skeletal changes similar to those reported in patients with burn injuries. Baseline, control, sham, and burned mice were injected with fluorescent markers calcein and tetracycline for histomorphometric analysis. Total femur dry and ash weights and total calcium content were significantly lower 10 days after burn injury compared with sham and control animals. There also were decreases in the percentage of fluorochrome-labeled bone surfaces and bone formation rates in the burn-injured mice compared with control and sham mice; however, there were no differences in the mineral apposition rates. This model now provides an opportunity to examine cellular and molecular mechanisms contributing to skeletal pathology in a well-defined burn injury model.

Animals↗