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Biomedical subjects

Michael Finkelstein

Publications and source records attributed to Michael Finkelstein.

5 recordsLinked to original sources

Influences of hyperbaric oxygen on blood pressure, heart rate and blood glucose levels in patients with diabetes mellitus and hypertension.

BACKGROUND: We investigated the influences of hyperbaric oxygen (HBO(2)) on systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and blood glucose level (BGL). METHODS: Forty one patients with hypertension (HTN), diabetes mellitus (DM), HTN and DM and/or no HTN or DM underwent HBO(2) sessions (15-40 sessions for each patient). SBP, DBP, HR and BGL (for diabetics) were recorded before and after each session. RESULTS: HBO(2) caused significant elevation in SBP (11%) and DBP (12%) and a decrease in HR (18%) (p <0.001). Patients with DM and HTN showed higher elevation in SBP and DBP. HBO(2) lowered BGL by 23% (p <0.001). When basal BGL was in the range of 120-170 mg/dl, it dropped to <100 mg/dl in 31/60 treatment sessions (52%). When basal BGL was <120 mg/dl it dropped to <70 mg/dl in 8/34 sessions. There was a possibility of lowered BGL when basal BGL was <170 mg/dl and a marked reduction in BGL occurred when basal BGL was <120 mg/dl. HBO(2) caused a marked elevation in SBP and DBP when basal SBP was >140 mmHg. Critical elevation was obtained when SBP was >160 mmHg. The use of beta blockers caused significant elevation of blood pressure while reducing HR. CONCLUSIONS: HBO(2) causes elevation of blood pressure and lowering of HR and BGL, which were augmented in the presence of HTN, DM, or beta blocker. The use of beta blockers for the management of HTN should be avoided during HBO(2) therapy.

Adrenergic beta-Antagonists↗

Analysis of temperature influences on the amplitude-frequency characteristics of Rn gas concentration.

The ventilation mechanism of Rn gas in underground environments is considered. Ventilation plays an important role in influencing the variability (harmonics) of Rn gas in the porous space below the earth's surface. We propose a new physical-environmental model of relating Rn gas concentrations to air temperature variations at the earth's surface. Applicability of this model was tested after searching for Rn gas indicators of geodynamic processes in two underground tunnels in central and southern Israel. The theoretical estimation of Rn gas concentrations shows a good agreement with the observed values. We demonstrate the possibility of Rn gas anomalies being caused by atmospheric temperature variations and the necessity to take these effects into account when investigating geodynamic processes.

Atmosphere↗

Root resorption: the possible role of extracellular matrix proteins.

During maxillary permanent canine eruption, the deciduous canine root is selectively resorbed while the adjacent permanent lateral incisor root is left intact. An understanding of this selective resorption could provide insights into the cause of moderate to severe iatrogenic root resorption during orthodontic tooth movement. This study investigated the possible role of extracellular matrix (ECM) proteins in the selective resorption process. The spatial expression patterns of 2 ECM proteins, osteopontin (OPN) and bone sialoprotein (BSP), were assessed within the periodontal ligament (PDL) surrounding root surface areas of deciduous and permanent teeth. Intact and resorbed root surface areas from 14 deciduous roots and intact root surface areas from 12 permanent tooth roots were examined. In the deciduous roots, BSP and OPN were locally expressed in the cell layer adjacent to the root surface and most intensely concentrated in areas surrounding and within odontoclasts proximal to the resorptive lacunae. In contrast, BSP and OPN were expressed in a generalized pattern throughout the PDL of permanent roots. These preliminary findings suggest a differential expression of ECM proteins on deciduous versus permanent tooth roots, which could act as a signal for selective odontoclast adhesion to, and subsequent resorption of, deciduous root surfaces.

Extracellular Matrix Proteins↗

Designing cases in problem-based learning to foster problem-solving skill.

The purpose of this study was to examine the effect of case segmentation schemes in problem-based learning (PBL) on the development of problem-solving skill, self-directedness and technical knowledge. Seventy-four dental education students were randomly assigned to 12 PBL groups. Six groups experienced PBL cases that were formatted in short segments and six groups experienced PBL cases that were formatted in long segments. Pretest measures of problem-solving skill, self-directedness and technical knowledge were administered at the beginning of the Fall 1998 semester. Students studied three PBL cases in their assigned groups in the ensuing semester. Posttest measures were administered at the conclusion of the semester. Analysis of the data found that students who experienced PBL with a short case segmentation scheme were better able to solve problems highly similar to the problems in the teaching cases than students who experienced PBL with a long case segmentation scheme. No significant differences were found for self-directedness, technical knowledge, or ability to solve problems distinctly different from the teaching cases. Explanations of these findings and their implications for research and practice in PBL are discussed.

Education, Dental↗

Hyperbaric oxygen in the treatment of patients with cerebral stroke, brain trauma, and neurologic disease.

Hyperbaric oxygen (HBO) therapy has been used to treat patients with numerous disorders, including stroke. This treatment has been shown to decrease cerebral edema, normalize water content in the brain, decrease the severity of brain infarction, and maintain blood-brain barrier integrity. In addition, HBO therapy attenuates motor deficits, decreases the risks of sequelae, and prevents recurrent cerebral circulatory disorders, thereby leading to improved outcomes and survival. Hyperbaric oxygen also accelerates the regression of atherosclerotic lesions, promotes antioxidant defenses, and suppresses the proliferation of macrophages and foam cells in atherosclerotic lesions. Although no medical treatment is available for patients with cerebral palsy, in some studies, HBO therapy has improved the function of damaged cells, attenuated the effects of hypoxia on the neonatal brain, enhanced gross motor function and fine motor control, and alleviated spasticity. In the treatment of patients with migraine, HBO therapy has been shown to reduce intracranial pressure significantly and abort acute attacks of migraine, reduce migraine headache pain, and prevent cluster headache. In studies that investigated the effects of HBO therapy on the damaged brain, the treatment was found to inhibit neuronal death, arrest the progression of radiation-induced neurologic necrosis, improve blood flow in regions affected by chronic neurologic disease as well as aerobic metabolism in brain injury, and accelerate the resolution of clinical symptoms. Hyperbaric oxygen has also been reported to accelerate neurologic recovery after spinal cord injury by ameliorating mitochondrial dysfunction in the motor cortex and spinal cord, arresting the spread of hemorrhage, reversing hypoxia, and reducing edema. HBO has enhanced wound healing in patients with chronic osteomyelitis. The results of HBO therapy in the treatment of patients with stroke, atherosclerosis, cerebral palsy, intracranial pressure, headache, and brain and spinal cord injury are promising and warrant further investigation.

Animals↗