Nucleotide sequence of an EF-1 alpha genomic clone from tomato.
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Amino Acid Sequence↗
Biomedical subjects
W R Hiatt
Publications and source records attributed to W R Hiatt.
Mechanical behavior of mandibular continuity defects reconstructed using combinations of hydroxylapatite and autogenous bone.
The purpose of this investigation was to determine the mechanical behavior of primate (Macaca mulatta) mandibles with continuity defects reconstructed using varying ratios of an alloplastic hydroxylapatite (HA) implant material mixed with autogenous bone (AB). The defects were allowed to heal for 6 and 18 months before killing the animals and mechanical testing. Each animal had one side of the mandible restored with 100% AB as control. The fracture strength and section modulus of the opposite side of the mandible, containing the test ratio of HA-AB, were directly compared with the mechanical behavior of the control side. The fracture strength and section modulus were evaluated by a cantilever type of mechanical test that took into account the anisotropic, viscoelastic, and geometric nature of the mandible. The type of bone and tissue at the fracture site was examined by scanning electron microscopy and a direct correlation between the amount of bone and/or fibrous tissue growth around the HA implant material and the fracture strength and section modulus values was established. The average fracture strength of the AB graft sites at 18 months was 9,975 +/- 4,300 psi, with ratios of 25:75 and 50:50 HA-AB giving test results approaching those of the AB graft sites.
Alveolar Ridge Augmentation↗
Restoration of mandibular continuity defects using combinations of hydroxylapatite and autogenous bone: microscopic observations.
The purpose of this investigation was to assess by light, transmission, and scanning electron microscopy the healing of mandibular continuity defects reconstructed with varying ratios of an alloplastic hydroxylapatite implant material (HA) mixed with autogenous bone (AB). This study reports the microscopic observations of implant and control sites at 6 and 18 months postsurgery. The results confirm the biocompatibility of dense HA granules. Specimens exhibited differing degrees of osseous regeneration that appeared related to the percent composition of HA. At 18 months, 86% and 91% of the HA granules were completely surrounded by bone in those specimens reconstructed with implants consisting of 25% and 50% HA, respectively. In contrast, specimens receiving implants consisting of 75% and 100% HA features osseous encapsulation of 75% and 66% of the granules, respectively. The results of this limited study indicate that dense HA granules mixed with AB in ratios ranging from 3:1 to 1:1 (AB:HA) may be successfully used as a bone extender during reconstructive surgery.
Animals↗
Diagnostic methods for peripheral arterial disease in the San Luis Valley Diabetes Study.
Peripheral arterial disease (PAD) is a frequent complication of diabetes mellitus. In the first phase of the San Luis Valley Diabetes Study, diagnostic criteria for PAD were evaluated in 607 controls and 343 diabetics. Normal ranges, and the lowest 2.5 percentile of the distribution of ankle/arm systolic blood pressure ratios were derived from a non-diabetic subset of the population with a very low probability of PAD. From this subgroup, abnormal ankle/arm ratios were defined as less than: 0.94 at rest, 0.73 after exercise, and 0.78 after reactive hyperemia. Using these criteria, PAD was identified in 130 subjects from the study population of 950 (prevalence of 13.7%). In contrast, a history of intermittent claudication, or an absent pulse in the extremity were uncommon findings in the study population, and thus had a low sensitivity and positive predictive value for PAD diagnosed by vascular laboratory criteria. We conclude that vascular laboratory tests provide a useful, and objective means of determining the prevalence of PAD in a geographically-based population of diabetic and control subjects.
Arteriosclerosis↗
Plasma catecholamine responses to exercise after training with beta-adrenergic blockade.
Exercise training has been shown to decrease plasma norepinephrine (NE) and epinephrine (EPI) levels during absolute levels of submaximal exercise, which may reflect alterations in sympathetic tone as a result of training. To determine if beta-adrenergic blockade altered these changes in the plasma concentration of catecholamines with exercise conditioning, we studied the effects of beta-adrenergic blockade on NE and EPI at rest and during exercise in 24 healthy, male subjects after a 6-wk exercise training program. The subjects were randomized to placebo (P), atenolol 50 mg twice daily (A), and nadolol 40 mg twice daily (N). There were no changes in resting NE and EPI compared with pretraining values in any subject group. During the same absolute level of submaximal exercise NE decreased in P and A but was unchanged in N, whereas EPI decreased only in P. At maximal exercise all three groups developed significant increases in NE after training that paralleled increases in systolic blood pressure. EPI at maximal exercise increased after training with N but was unchanged with P or A. These training-induced changes in plasma catecholamine levels were masked or blunted when the A and N groups were studied while still on medication after training. Thus beta-adrenergic blockade has important effects on adaptations of the sympathetic nervous system to training, especially during submaximal exercise.
Adrenergic beta-Antagonists↗
Benefit of exercise conditioning for patients with peripheral arterial disease.
Patients with atherosclerotic peripheral arterial disease (PAD) of the lower extremities have impaired walking ability due to exercise-induced muscle ischemia and the resultant pain of intermittent claudication. To evaluate the benefit of exercise training as a treatment for patients with PAD, as well as possible mechanisms associated with improvement, we randomly assigned 19 men with disabling claudication to treated and control groups. Treatment consisted of supervised treadmill walking (1 hr/day, 3 days/wk, for 12 weeks) with progressive increases in speed and grade as tolerated. Graded treadmill testing was performed to maximal toleration of claudication pain on entry and after 12 weeks of training to define changes in peak exercise performance. After 12 weeks, treated subjects had increased their peak walking time 123%, peak oxygen consumption 30%, and pain-free walking time 165% (all p less than 0.05). Control subjects had no change in peak oxygen consumption, but after 12 weeks, peak walking time increased 20% (p less than 0.05). In treated subjects, maximal calf blood flow (measured by a plethysmograph) increased 38 +/- 45% (p less than 0.05), but the change in flow was not correlated to the increase in peak walking time. Elevated plasma concentrations of acylcarnitines have been associated with the functional impairment of PAD and may reflect the metabolic state of ischemic skeletal muscle. In treated subjects, a 26% decrease in resting plasma short-chain acylcarnitine concentration was correlated with improvement in peak walking time (r = -0.78, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Carnitine↗
Structure and expression of elongation factor 1 alpha in tomato.
A full-length cDNA clone, LeEF-1, has been isolated from tomato for the alpha subunit of elongation factor 1 (EF-1 alpha), a polypeptide which plays a central role in protein synthesis. The 448 amino acid protein encoded by this cDNA appears highly homologous to other EF-1 alpha s having a high degree of similarity (75-78%) to EF1 alpha previously described from both lower eukaryotes and animals. Southern analysis indicated that EF-1 alpha belongs to a small multigene family of 4-8 members in tomato. The pattern of expression of EF-1 alpha mRNA in various tomato tissues was analyzed by Northern analysis, in vitro translation and in situ hybridization. EF-1 alpha mRNA is an abundant species and higher levels of mRNA were found in developing tissues such as young leaves and green fruit compared to the mRNA levels observed in older tissues. The increased levels of EF-1 alpha mRNA therefore appear to correlate with higher levels of protein synthesis in developing tissues.
Amino Acid Sequence↗
Exercise haemodynamic effects of beta-blockade and intrinsic sympathomimetic activity.
Beta-adrenergic blockade with intrinsic sympathomimetic activity (ISA) causes less depression of resting and submaximal heart rate (HR) than non-ISA beta-blockers. The effects of these drugs on exercise haemodynamics have not been well studied. We evaluated effects of pindolol, propranolol and placebo during rest and steady-state exercise on cardiac output, oxygen consumption, calf blood flow, HR and blood pressure in 18 healthy subjects. Pindolol 5 mg and propranolol 80 mg given twice daily, reduced maximal exercise HR by 50 and 52 beats.min-1 respectively, confirming similarity of beta 1-blockade. Resting cardiac output was unchanged in all three groups after one week of therapy. Cardiac output, measured during steady-state exercise decreased in the propranolol group (18.3 vs 15.6 l.min-1) with no significant changes in pindolol (15.7 vs 16.01.min-1) or placebo (18.6 vs 17.3 l.min-1). The rise in cardiac output, from rest to exercise, was similarly attenuated by propranolol but not by pindolol or placebo. Exercise stroke volume increased 12% on pindolol (123-140 cc) and decreased 7% on propranolol (143-133 cc). Neither drug had a detrimental effect on exercise calf blood flow compared to placebo. Thus, unlike propranolol, pindolol with ISA, maintains a normal cardiac output during submaximal exercise.
Adult↗
Nutrition and the head and neck cancer patient.
Patients with head and neck cancer have a unique nutritional problem that can affect their response to treatment. To properly manage these patients the oral and maxillofacial surgeon must be able to accurately assess their nutritional status and implement the proper metabolic treatment. This article reviews the benefits of nutritional support, the methods of patient assessment and nutritional repletion, and the advantages and disadvantages of the various alimentation modalities. Also, an analysis of the relationship of nutritional status and the surgical course of the head and neck cancer patient at our institution is presented.
Head and Neck Neoplasms↗
Extubation criteria for oral and maxillofacial surgery patients.
An overview is presented of some of the factors that should be considered before extubating a patient who has undergone an oral and maxillofacial surgical procedure. A discussion of the possible preoperative assessment of the patient, complications of intubation, effects of narcotics and muscle relaxants, assessment of airway edema, and criteria for extubation is included.
Airway Obstruction↗
A technique of fixation of costochondral grafts for reconstruction of the temporomandibular joint.
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Bone Plates↗
Venous occlusion plethysmography reduces arterial diameter and flow velocity.
The measurement of peripheral blood flow by plethysmography assumes that the cuff pressure required for venous occlusion does not decrease arterial inflow. However, studies in five normal subjects suggested that calf blood flow measured with a plethysmograph was less than arterial inflow calculated from Doppler velocity measurements. We hypothesized that the pressure required for venous occlusion may have decreased arterial velocity. Further studies revealed that systolic diameter of the superficial femoral artery under a thigh cuff decreased from 7.7 +/- 0.4 to 5.6 +/- 0.7 mm (P less than 0.05) when the inflation pressure was increased from 0 to 40 mmHg. Cuff inflation to 40 mmHg also reduced mean velocity 38% in the common femoral artery and 47% in the popliteal artery. Inflation of a cuff on the arm reduced mean velocity in the radial artery 22% at 20 mmHg, 26% at 40 mmHg, and 33% at 60 mmHg. We conclude that inflation of a cuff on an extremity to low pressures for venous occlusion also caused a reduction in arterial diameter and flow velocity.
Adult↗
Carnitine and acylcarnitine metabolism during exercise in humans. Dependence on skeletal muscle metabolic state.
Carnitine metabolism has been previously shown to change with exercise in normal subjects, and in patients with ischemic muscle diseases. To characterize carnitine metabolism further during exercise, six normal male subjects performed constant-load exercise on a bicycle ergometer on two separate occasions. Low-intensity exercise was performed for 60 min at a work load equal to 50% of the lactate threshold, and high-intensity exercise was performed for 30 min at a work load between the lactate threshold and maximal work capacity for the individual. Low-intensity exercise was not associated with a change in muscle (vastus lateralis) carnitine metabolism. In contrast, from rest to 10 min of high-intensity exercise, muscle short-chain acylcarnitine content increased 5.5-fold while free carnitine content decreased 66%, and muscle total carnitine content decreased by 19% (all P less than 0.01). These changes in skeletal muscle carnitine metabolism were present at the completion of 30 min of high-intensity exercise, and persisted through a 60-min recovery period. With 30 min of high-intensity exercise, plasma short-chain and long-chain acylcarnitine concentrations increased by 46% and 23%, respectively. Neither exercise state was associated with a change in the urine excretion rates of free carnitine or acylcarnitines. Thus, alterations in skeletal muscle carnitine metabolism, characterized by an increase in acylcarnitines and a decrease in free and total carnitine, are dependent on the work load and, therefore, the metabolic state associated with the exercise, and are poorly reflected in the plasma and urine carnitine pools.
3-Hydroxybutyric Acid↗
The nucleotide sequence of the 5' flanking region of a tomato polygalacturonase gene.
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Amino Acid Sequence↗
Ameloblastic fibrosarcoma.
Ameloblastic fibrosarcoma is an extremely rare tumor. To date only 43 cases have been reported in the literature. An additional case of ameloblastic fibrosarcoma is presented; the clinical features, histologic characteristics, treatment, and the relevance of the presence of dental hard tissue are discussed.
Adult↗
Congenital teratoid cyst of the floor of the mouth.
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Humans↗
Condylar positioning in orthognathic surgery.
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Bone Plates↗
Age does not alter human vascular and nonvascular beta 2-adrenergic responses to isoproterenol.
beta-Adrenoceptor-mediated functions appear to diminish with aging, but the exact scope of these changes is unknown, because most studies have been limited to beta 1-adrenergic cardiac phenomena. To evaluate both a vascular and a nonvascular beta 2-adrenergic response in the aged, we have studied 12 healthy elderly and 12 healthy young subjects infused with increasing doses of isoproterenol and compared the change in peripheral vascular resistance, measured by venous occlusion plethysmography, and insulin release. In both groups vascular resistance fell and insulin concentrations increased. These changes were equivalent in both groups, and we therefore infer no significant decline in either of these beta 2-adrenergic functions in the elderly.
Adult↗