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Biomedical subjects

S H Miller

Publications and source records attributed to S H Miller.

At least 37 records · Page 2Linked to original sources
PubMed1991

Studies with abanoquil (UK-52,046) a novel quinoline alpha 1-adrenoceptor antagonist: II. Duration of action, pharmacokinetics and concentration-effect relationships in normotensive subjects.

1. This study further examines the quinoline-derivative abanoquil with particular respect to the duration of its alpha 1-adrenoceptor antagonist activity and its concentration-effect relationship following a single intravenous bolus dose of 0.5 micrograms kg-1 in young, normotensive males. 2. alpha 1-adrenoceptor antagonism (as assessed by phenylephrine pressor responses) was detectable for up to 12 h post dosing: at 12 h there was a significant 1.5-fold rightward shift (95% CI: 2.2 to 1.1) of the pressor dose-response curve for diastolic blood pressure. 3. Despite evidence of substantial alpha 1-adrenoceptor antagonism abanoquil had no significant effect on blood pressure, supine and erect, but there were small and statistically significant increments in heart rate. 4. The degree of alpha 1-adrenoceptor antagonism was related to whole blood concentrations abanoquil: the PD-ratios of phenylephrine pressor responses performed at 1, 6, and 12 h post dosing were significantly correlated with log drug concentrations (r = 0.57 for systolic (P less than 0.05) and r = 0.78 for diastolic blood pressure (P less than 0.005). 5. In conclusion, abanoquil produced significant alpha 1-adrenoceptor antagonism which was related to circulating drug concentrations. The absence of other significant cardiovascular effects suggests that abanoquil warrants further clinical study as an antiarrhythmic agent.

Adrenergic alpha-Antagonists↗
PubMed1990

Chronic swim stress enhances the motoric inhibiting effects of a muscarinic agonist.

The authors previously demonstrated that chronic inescapable swim stress and footshock increase the capacity of a fixed dose of a muscarinic agonist to produce hypothermia in the rat. This project was designed to determine whether chronic inescapable swim stress in cold water would render a low dose of a muscarinic agonist, devoid of an effect on motor behavior in the naive rat (i.e., prior to subjection to the course of swim stress), an inhibitor of mobility. The study involved two groups of rats, an experimental group which received arecoline and a control group which received saline five minutes prior to being placed in an open field. Number of crossings, the dependent variable, was measured in both groups before and after a 14-day course of twice daily inescapable swim stress of 10 minutes duration at 12 degrees C. The arecoline-treated group, as hypothesized, exhibited a significantly greater reduction in number of crossings than the saline-treated groups following the course of swim stress.

Animals↗
PubMed1990

Healing in the irradiated wound.

Poor or nonhealing of irradiated wounds has been attributed to progressive obliterative endarteritis. Permanently damaged fibroblasts may also play an important part in poor healing. Regardless of the cause, the key to management of irradiated skin is careful attention to prevent its breakdown and conservative, but adequate, treatment when wounds are minor. When wounds become larger and are painful, complete excision of the wound or ulcer is called for and coverage should be provided by a well-vascularized nonparasitic distant flap.

Humans↗
PubMed1989

Effectiveness of prophylactic mastectomy in the prevention of breast tumors in C3H mice.

The effectiveness of prophylactic mastectomy in the prevention of breast tumors was studied in spontaneous breast-tumor-forming C3H mice. Prolactin levels were assayed to determine if this hormone was related to the incidence of mammary tumors. Two-hundred and fifty-six 1-month-old C3H mice were divided into four groups (control, 1; sham surgery, 2; mammectomy 50 percent, 3; and mammectomy 100 percent, 4). At the time of sacrifice (0 to 1 year postoperatively) estrus cycles were determined, ventral skin (breast) and ovaries were removed for histology, and serum was collected for prolactin assays. Prolactin levels 24 hours postoperatively were significantly elevated (p less than 0.01) in groups 2 to 4 when compared with group 1. Six months postoperatively, prolactin levels were significantly higher (p less than 0.05) in mice with tumors compared with those without tumors in groups 3 and 4. There were no differences in tumor incidence between the four groups. At 12 months postoperatively, no differences in prolactin levels were noted, but group 2 animals had the highest incidence of mammary tumors (89 percent; p less than 0.01) when compared to groups 3 and 4. Mammary tumor incidence was not decreased by 50 percent or 100 percent mammectomy in C3H mice. Prolactin levels rose in response to surgery and/or anesthesia and remained elevated only in tumor-bearing mice who underwent mammectomy, an occurrence similar to that reported in humans.

Adenocarcinoma↗
PubMed1988

The effect of food on the absorption of slow-release isosorbide-5-mononitrate tablets.

The influence of food on the absorption characteristics of slow release isosorbide-5-mononitrate tablets was investigated in 10 normal healthy volunteers. There were no differences in the peak concentration achieved or the area under the curve, but the peak concentration occurred later when the drug was administered after food. The apparent elimination half-life ranged from 4.7 to 10.1 h. Bioavailability of slow-release isosorbide-5-mononitrate is therefore unaffected by food, but there is a slower rate of absorption.

Absorption↗
PubMed1988

Effects of phenylephrine on tissue gas tension, bleeding, infection, and lidocaine absorption.

In an attempt to find a vasoconstrictor with less detrimental local and systemic effects than epinephrine, the effects of phenylephrine, a pure alpha agonist, on tissue gas tension, bleeding, infection rates, and lidocaine absorption were studied. All concentrations of phenylephrine significantly reduced tissue PO2 within 10 minutes of injection, and reduction of PO2 was dose-dependent. Phenylephrine 1:10,000 produced significant bacterial growth when simultaneously injected with 6 X 10(6) Staphylococcus aureus. Bacterial growth was insignificant with 1:20,000 phenylephrine and absent with 1:40,000 phenylephrine. Blood loss from a standard wound was significantly reduced at all concentrations of phenylephrine. Lidocaine absorption was significantly reduced with 1:20,000 and 1:40,000 phenylephrine. In a rat model, 1:40,000 phenylephrine significantly reduced blood loss and lidocaine absorption, produced minimal reduction of tissue PO2, and did not enhance bacterial invasion.

Adsorption↗
PubMed1988

Improved imaging of the augmented breast.

The breast containing an augmentation implant presents a challenge to the mammographer and is often considered unsuitable for adequate mammographic evaluation. A modified positioning technique is described. By displacing the implant posteriorly against the chest wall and pulling breast tissue over and in front of the implant, marked improvement in compression and visualization of substantially more breast tissue is achieved. Over 250 patients with augmentation implants have been successfully studied with this modified compression technique. After review of 50 consecutive cases, two experienced mammographers confirmed a significant improvement in image quality, amount of breast tissue visualized, and overall benefit of the modified technique. Modified positioning for women with breast implants substantially improves both image quality and amount of breast tissue imaged.

Breast↗
PubMed1987

Management of burned long bones.

The management of severely burned and exposed supportive osseous tissues is not fully standardized. We present two patients in whom extensive debridement and decortication of the involved bone may have contributed to subsequent stress fractures. We propose an alternative therapeutic approach for this problem, including: minimal debridement of the bone, early coverage of the exposed bone with vascularized muscle, and adequate prophylactic protection.

Adult↗
PubMed1987

Craniofacial biostereometrics.

We believe that biostereometrics can be useful to the craniofacial surgeon in providing a highly accurate, reproducible diagnostic and presurgical tool that is inexpensive and noninvasive. It can help visualize complex pathologic bony abnormalities, resolve ambiguous CT scans, and predict soft-tissue changes secondary to alterations in bony contours when used in conjunction with CT scans and cephalograms.

Face↗
PubMed1986

Tissue expansion as an adjunctive technique for the management of difficult wounds.

Replacement of lost or injured tissues with similar tissues is a major goal of the reconstructive surgeon. A relatively new modality, tissue expansion, appears to be an helpful adjunct in achieving this goal by providing tissues for reconstruction that are near at hand, possess similar characteristics to the lost tissue, and can even enhance vascularity within an ischemic area. Although the technique is a useful one, its indications and contraindications are incompletely defined. We have used this technique 65 times in 42 patients during a 2 1/2 year period. The overall complication rate has been 22 percent, similar to other reconstructive techniques, but the consequences of these complications have been relatively minor and have not, for the most part, added significantly to patient morbidity.

Adolescent↗
PubMed1986

Juvenile aponeurotic fibroma with disseminated fibrosarcoma.

Juvenile aponeurotic fibromas, although locally recurrent, generally do not metastasize. This observation supports the practice of incomplete excision of the tumor to preserve the function of the involved extremity. We report on a patient with a juvenile aponeurotic fibroma of the palm, who returned 5 years after the second local surgical excision with metastatic fibrosarcoma of the lungs and bones.

Adipose Tissue↗
PubMed1986

Hemodynamic alterations secondary to an electrical burn in the rat: a pilot study.

Rats subjected to a standard electrical burn of 250 volts for 10 seconds receive a severe injury stimulating a pronounced systemic circulatory response. Initial postinjury hyperemia is replaced by a low perfusion state within 24 hours. Our study demonstrates the difficulty in isolating regional microcirculatory alterations under such circumstances. Modification of the burn model or the method of fluid resuscitation may minimize the influence of this dynamic systemic response.

Animals↗
PubMed1986

Attempts to improve tissue survival during ex vivo storage.

Ex vivo hypothermic perfusion has been shown to enhance short-term survival of organs before transplantation. The effects of perfusion, control of media pH, and systemic drug treatment were studied utilizing superficial epigastric free flaps in Sprague-Dawley rats. Viability of the flaps could be reliably maintained (9/10, 90%) for 72 hours using simple storage in phosphate-buffered Ringer's (pH 7.8) at 4 degrees C. Pretreatment with prostaglandin E1 was of slight benefit. Flap perfusion with or without pharmacologic agents was not beneficial.

Animals↗
PubMed1986

Repeated skin expansion to resurface a massive thigh wound.

We report here a patient who sustained posttraumatic skin and soft-tissue loss of the right thigh. Replacement of approximately 750 cm2 of split-thickness skin graft with adjacent skin serially expanded and advanced demonstrates the applicability of this technique to cover large tissue defects. Despite infection and exposure, we believe that expansion can proceed safely on an outpatient basis, providing that systemic toxicity does not develop and the exposure does not mechanically preclude expansion.

Child↗
PubMed1986

Use of ultrasound to locate a "lost" tissue expander injection port.

We have presented a rapid and reliable method of finding lost injection valves. (A frustrating footnote, however, is that 1 week later the port had again migrated and could not be located. Since the further anticipated gain was marginal, the bladder was already nearly expanded, and the expense for repeated ultrasound was a consideration, no further attempts were made to locate this port by ultrasound for further filling).

Aged↗