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Biomedical subjects

H D Hall

Publications and source records attributed to H D Hall.

At least 55 records · Page 3Linked to original sources
PubMed1987

Acute lung inflammation in rats induced by phorbol myristate acetate (PMA).

Intratracheal administration of PMA produces acute lung injury in part due to the generation of O2-derived free radicals. This study evaluated the role of the antioxidant enzyme superoxide dismutase (SOD) in PMA-induced lung injury in the rat. PMA was instilled into rats intratracheally (20-60 micrograms/kg), and the lungs were lavaged 4 hr later. Total number of cells recovered from lavage after PMA treatment was not different from the total number recovered from controls; lavagable PMNs increased in a dose-dependent manner. Albumin in lavage fluid (an index of lung vascular permeability) was significantly increased at 60 micrograms/kg PMA. SOD (10,000 U) + PMA (60 micrograms/kg) reduced the albumin level but significantly increased both total number of cells and number of PMNs recovered from lavage fluid. To investigate the possibility that SOD decreases the ability of PMNs to adhere, PMN aggregation was measured in vitro. The results indicated that 10,000 U SOD can inhibit PMA-induced aggregation by 50%. In contrast, aggregation to other stimuli (e.g., fMet-Leu-Phe, A23187) was unaffected by SOD. We conclude SOD prevents PMA-induced lung permeability and diminishes PMN adherence.

Animals↗
PubMed1987

Muscarinic receptors of rat parotid gland enlarged by gland ablation and bulk diet. Effects of denervation.

The density of muscarinic binding sites was increased 10% in the rat parotid gland enlarged (2 times control) as a result of ablation of the submandibular-sublingual glands and maintenance of rats on bulk diet (50% inert cellulose plus 50% solid chow) for 4 weeks. When either the parasympathetic or sympathetic innervation to the gland was unilaterally removed at the time of submandibular-sublingual ablation and introduction of the bulk diet, the density of muscarinic receptors showed an even greater increase from levels of innervated glands of chow-fed controls (29%); with removal of both nerves, the increase was 39%. A 36% increase in cyclic guanosine monophosphate levels accompanied the increase in receptors of the enlarged gland, but when the parotid was denervated, there was no change in cyclic GMP. Absence of either or both nerves led to a maximal decrease of 24-29% in density of muscarinic receptors of parotid gland of chow-fed controls, but to no change in cyclic GMP levels. While autonomic influences mediate the changes in density of muscarinic receptors of parotid gland of chow-fed rats, some additional factor is apparently involved in their increase in the enlarged gland.

Animals↗
PubMed1987

Further refinement and evaluation of intraoral vertical ramus osteotomy.

Eighty-nine patients were treated with a modified procedure for intraoral vertical ramus osteotomy. Complications were virtually eliminated except for damage to the inferior alveolar nerve. Acute nerve damage occurred in about 36% of operated sides. Seventy-four percent of these damaged nerves recovered fully by one year. Only 8% of operated sides had persistent diminished sensation, usually mild, of the lower lip and chin. It is concluded that this technique should be seriously considered for mandibular ramus osteotomies when the mandible is going to be retruded or minimally moved in any other direction.

Cephalometry↗
PubMed1987

Beta-adrenergic and muscarinic receptors of parotid gland following maintenance of rats on liquid diet.

Parotid gland of adult rats maintained exclusively on liquid (milk) diet for 7 or 13 days showed a 25% reduction in number of beta-adrenoceptors, and after 21 days, the reduction was 33%; with maintenance of rats on Metrecal for 7 days, the decrease was 24% for female rats and 22% for male rats. The decrease in number of muscarinic receptors after 7 or 13 days on milk was 32%, and 38% after 21 days; the decreases for rats on Metrecal for 7 days were 32% for females and 35% for males. In rats maintained on liquid (milk) diet for 7 days, and then denervated by unilateral removal of the parasympathetic and sympathetic innervations to parotid there were decreases of 39-42% in number of beta-receptors and 50-52% in muscarinic receptors at 6 or 14 days after denervation (maintenance on liquid diet for 13 and 21 days, respectively) from those of innervated glands of chow-fed rats; denervated glands of rats on chow diet showed the same reduction. Thus, it was concluded that absence of neurally mediated glandular activity, imposed by either diet or surgical removal of the nerves, caused marked decreases in number of both beta-adrenergic and muscarinic receptors, but that the presence of the nerves, even though inactive (liquid diet), provided a trophic influence that prevented the more marked decreases seen in the absence (surgical removal) of the nerves.

Animals↗
PubMed1986

Beta-adrenoceptors in the rat parotid gland enlarged by salivariectomy and bulk diet. Effects of denervation.

The numbers of beta-adrenergic receptors and level of cyclic AMP (cAMP) of the parotid gland of adult female rats were determined 4 weeks after introduction of a regimen that induced a 2-fold increase in gland weight. This regimen consisted of ablation of the submandibular-sublingual glands and substitution of the normal chow diet with a bulk diet consisting of 50% inert cellulose and 50% ground solid chow. There was a 2.4-fold increase in number (density) of beta-adrenoceptors in the enlarged parotid gland when comparison was made with parotid glands of control rats. The beta-adrenoceptor present in the enlarged and normal glands was of the beta 1 subtype. Removal of either autonomic pathway at the time of partial salivariectomy and dietary substitution was followed by a small reduction in number of beta-adrenoceptors (4-9% with either denervation), but when both nerves were removed the reduction was 25%; in magnitude, these changes were generally similar to those observed with denervated parotid glands of chow-fed rats. The norepinephrine concentration of the enlarged gland was much less than that of normal glands (reduced 38%); sympathectomy of normal or enlarged parotid glands resulted in a marked lowering of norepinephrine concentrations (to 1-5% of control levels); parasympathectomy had no effect on norepinephrine concentration of enlarged parotid glands but caused a decrease in that of the parotid of normal size. Apparently, the number of beta-adrenoceptors depends on the degree of activity of both the parasympathetic and sympathetic nerves to the parotid.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Public health and AIDS.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Meniscectomy for damaged disks of the temporomandibular joint.

Internal derangements of the temporomandibular joint are now known to be a common cause of pain in the joint area. Several specific surgical treatments for this disorder are advocated, but none is yet well established. Meniscectomy has been one of the more commonly done procedures. While published results of meniscectomy are encouraging, there are few details upon which to base opinions. In this study, meniscectomy was performed in 40 joints with seriously deformed disks. A detailed analysis of the results lends further support to the effectiveness of this form of treatment.

Adolescent↗
PubMed1984

An improved method for treatment of facial asymmetry secondary to jaw deformity.

Current methods of treating facial asymmetry secondary to jaw deformity do not take into consideration asymmetry in the gonial angle areas. An instrument was developed for measuring such asymmetry. A second instrument was developed that permits predictable repositioning of the jaws during surgical correction. Use of these two instruments is illustrated in eight cases. Results suggest that it is now possible to correct facial asymmetry, including posterior facial asymmetry, in a one-stage surgical procedure.

Dental Articulators↗
PubMed1983

Early results of secondary bone grafts in 106 alveolar clefts.

Eighty-three patients with cleft lip and cleft palate were treated by secondary bone grafts to the 106 alveolar clefts. In 98% of the alveolar clefts, the graft was successful and the oronasal fistula was closed. There were only occasional other complications, all but one of which were minor and did not affect the final result. Morbidity was low. Compared with older patients, the pre-teen group of patients not only had no complications of consequence but experienced less morbidity. The 100% success rate and the lower morbidity in the pre-teen group of patients thus favor operating on patients at the younger age.

Adult↗
PubMed1980

Jaw-wiring for obesity.

Fourteen of nineteen-self referred obese women were treated for weight reduction by jaw-wiring. Most were immature, passive-dependent or passive-aggressive personalities. Only one-third of the group completed the study, which was six months in length. All lost weight initially, but about two-thirds later regained some weight. At first all responded with enthusiasm, but later most felt discouraged and found jaw-wiring difficult to accept. Only two patients derived significant benefit. There were no dental complications. Jaw-wiring appears to be a safe but ineffective means of controlling weight, especially if applied to patients with poor motivation and immature personalities.

Adult↗
PubMed1978

Neural regulation of compensatory enlargement of the parotid gland of the rat.

The role of the innervation in mediating compensatory enlargement of the parotid gland of the rat after partial desalivation was examined. The results of denervation experiments show that full compensatory growth requires both parasympathetic and sympathetic innervation. The presence of the parasympathetic innervation alone results in an increase in the number of cells, but not the size of the cells. The sympathetic innervation alone does not mediate either response. We, therefore, conclude that the two types of innervation have a synergistic action on the parotid to produce the maximal compensatory response, which includes an increase in both number and size of acinar cells.

Animals↗
PubMed1977

Functional mediation of compensatory enlargement of the parotid gland.

The role of functional activity in mediating compensatory enlargement of the parotid gland after removal of the other major salivary glands was investigated. Increased levels of activity were achieved by feeding rats a bulk diet. Conversely, a liquid diet was used to reduce the functional demands on the parotid. It was found that the liquid diet completely prevented the compensatory response from occurring. Bulk diet, on the other hand, caused an even greater compensatory response than did the standard chow diet. Compensatory enlargement of the parotid, therefore, depends on its functional activity and not on other, e.g., humoral factors dissociated from function. The character of the cellular response in compensatory enlargement was also examined. The chow diet caused compensatory enlargement by an increase in cell size with little, if any, increase in cell number.

Animals↗