Biomedical subjects

J R Ryan

Publications and source records attributed to J R Ryan.

At least 55 records · Page 3Linked to original sources

PubMed1986

Comparison of effects of oral and intravenous famotidine on inhibition of nocturnal gastric acid secretion.

In this double-blind, placebo-controlled, four-way crossover, randomized study, eight high-secretor (more than 5 meq per hour) volunteers received 20 mg of famotidine by mouth, 10 mg intravenously, and 20 mg intravenously at 9 P.M. Volume, acid content, and pH of continuous gastric aspirates were measured hourly from one to at least 12 hours after treatment. Plasma concentrations of famotidine were determined at specified intervals. All famotidine doses produced marked suppression of gastric secretion. The mean total output was 1,196.3, 526.8, 414.9, and 518.0 ml for placebo, the 10-mg intravenous famotidine dose, the 20-mg intravenous dose, and the 20-mg oral dose, respectively. The latter three values were significantly different from that of placebo at p less than 0.01. The mean total acid output was 105.3, 8.3, 2.3, and 6.2 meq, respectively, and the acid output for all three doses was significantly different from that of placebo at p less than 0.01. The onset of antisecretory effect was noted as early as one hour after dosing. The mean gastric aspirate pH values were 1.7, 5.5, 6.2, and 4.4 during the second hour after placebo, the 10-mg intravenous dose, the 20-mg intravenous dose, and the 20-mg oral dose, respectively, with the treatment pH values significantly different from the placebo pH value at p less than 0.01. Higher mean pH values were reached at seven, eight, and nine hours after the 20-mg intravenous dose than after the 10-mg intravenous dose (p less than 0.05). By the 12th hour after administration of the 10-mg intravenous dose, pH values had returned to baseline in all but one subject. After the 20-mg intravenous dose, a similar loss of effect occurred in one subject at 12 hours and in all subjects by 15 hours. Plasma concentrations of famotidine greater than 50 ng/ml were associated with an acid output inhibition of more than 80 percent, whereas high (more than 90 percent) as well as low (less than 50 percent) inhibition was observed at famotidine concentrations below 50 ng/ml.

Administration, Oral↗

PubMed1986

Comparison of oral nalbuphine, acetaminophen, and their combination in postoperative pain.

This double-blind, randomized, parallel, placebo-controlled study evaluated the analgesic effects of single oral doses of 30 mg nalbuphine, 650 mg acetaminophen, and the contribution of each to the efficacy of their combination in 128 hospitalized patients with postoperative pain. Subjective reports of patients evaluated each hour for 6 hours were used as indices of analgesic response. Both nalbuphine and acetaminophen were significantly superior to placebo for most measures of total and peak analgesia. The interaction contrast between nalbuphine and acetaminophen was not significant for any analgesic measurements, indicating an additive effect of the components. The combination was the most effective treatment, followed by nalbuphine, acetaminophen, and placebo. Effects of the combination were significantly different from those of acetaminophen at 4, 5, and 6 hours and from those of placebo at 1 to 6 hours. There was no significant difference in the frequency or intensity of side effects among the groups. The combination of nalbuphine and acetaminophen appears to be a therapeutically useful combination.

Acetaminophen↗

PubMed1986

Development of gallbladder contractility in the guinea pig.

In vitro experiments were performed to examine the contractile responsiveness of guinea pig gallbladder smooth muscle as a function of developmental age. Gallbladder muscle strips from preterm (day 50-55 gestation), newborn (days 1-3 post partum), and 1-month-old animals were stimulated with agonists that initiate the contractile process either by activation of membrane receptors (acetylcholine and the octapeptide of cholecystokinin) or by membrane depolarization (potassium). Dose-response curves were constructed for each agonist in each age group and analyzed with respect to the maximal force developed and the pD2 value (negative logarithm of the dose of agonist which produces a one-half maximal response). The results can be summarized as follows: 1) when normalized for tissue cross-sectional area, the magnitude of the contractile response to each agonist increased with increasing developmental age; 2) the dose of agonist required to elicit a one-half maximal response was independent of developmental age. The data indicate that cholinergic and cholecystokinin receptors are present and functional on gallbladder smooth muscle prior to birth and that the force generating capacity of the tissue continues to develop after birth. A reduced contractility of the gallbladder in preterm and newborn animals as compared to young adults may partially explain the decreased choledochol bile flow seen in the neonate.

Acetylcholine↗

PubMed1986

Multiple myxomata of soft tissue associated with polyostotic fibrous dysplasia. A case report.

Polyostotic fibrous dysplasia with associated myxomata of soft tissue has been reported rarely. In most cases, the patient appears first with fibrous dysplasia and many years later presents with soft-tissue tumors. This is a report of a 57-year-old woman--an unusual case of soft-tissue myxomas with fibrous dysplasia. This case suggests that a patient developing myxomatous tumors of the soft tissues might be evaluated for the possibility of associated fibrous dysplasia.

Female↗

PubMed1986

Prophylactic femoral stabilization with the Zickel nail by closed technique.

From 1974 to 1983, forty-three femora in forty patients with metastases to the subtrochanteric area were stabilized using a Zickel subtrochanteric device. Thirty-five patients with thirty-eight stabilized femora could be evaluated at follow-up times ranging from thirty-seven days to five years and one month. In twenty-eight of the thirty-eight femora, a modified technique for insertion of the device had been used. Twenty-eight (80 per cent) of the patients were able to walk after an average of 3.8 days. No patient who had been able to walk preoperatively lost that ability. The average length of survival was 312 days postoperatively. Fifteen patients survived for at least fifteen months and five patients, with an average length of survival of 1276 days, were still alive at the time when this review was initiated. Complications included four perioperative deaths, one non-fatal pulmonary embolus, and five intraoperative technical complications--four of them occurring before the described modification of the technique was instituted. There were no infections and no failures of the device. No patient had a loss of stability after Zickel nailing. The modification of the technique allows safer introduction of the intramedullary nail into the weakened but intact femur by a closed method.

Adult↗

PubMed1985

Acquired immune deficiency syndrome--related lymphadenopathies presenting in the salivary gland lymph nodes.

Homosexual males at risk for acquired immune deficiency syndrome (AIDS) frequently present with peripheral lymphadenopathies that precede the opportunistic infections and neoplasias of this disease. Two homosexual males had enlarged salivary glands due to lymphadenopathies initially affecting intraparotid and perisubmaxillary gland lymph nodes. Both the hyperplastic and the atrophic histologic patterns of AIDS-related lymphadenopathies were observed in the lymph nodes. Subsequently, the two patients developed lymphoma and opportunistic infections, respectively. The AIDS-related lymphadenopathy developing in salivary gland lymph nodes is an entity that should be considered in the differential diagnosis of salivary gland tumors.

Acquired Immunodeficiency Syndrome↗

PubMed1985

The influence of liver dysfunction on the pharmacokinetics of carprofen.

The pharmacokinetics of the investigational agent carprofen were examined in 12 patients with liver dysfunction (hepatic cirrhosis) and in six normal volunteers following single 100-mg oral administration of carprofen. In addition, three patients with acute hepatitis received a single 100-mg dose during the acute phase of the disease, and two of these patients received the same dose after they had convalesced. The pharmacokinetic parameters and urinary excretion data did not differ significantly (P greater than 0.05) between patients with hepatic cirrhosis and healthy volunteers. The mean +/- SD area under plasma concentration-time curve and apparent oral plasma clearance values were 57.8 +/- 11.7 micrograms X h/mL and 30.0 +/- 6.3 mL/min, respectively, in patients and 52.4 +/- 11.3 micrograms X h/mL and 33.1 +/- 7.2 mL/min in normals. The respective harmonic mean elimination half-lives were 10.5 and 9.4 hours. The 0-24 hour urinary recovery of intact drug and the glucuronide conjugate were 7.0 +/- 4.9% and 28.9 +/- 11.0%, respectively, in patients compared to 5.5 +/- 7.1% and 20.1 +/- 12.3% in normal subjects. The results of this study showed that liver dysfunction (hepatic cirrhosis) had no effect on the pharmacokinetic profile of carprofen. In the two patients with acute hepatitis who completed the study, the results suggest that the apparent oral clearance of carprofen may increase during the acute phase of the disease.

Adult↗

PubMed1985

Clinical pharmacology of acebutolol.

The clinical pharmacology and pharmacokinetics of acebutolol are summarized. Acebutolol and its longer-acting metabolite, diacetolol, are rapidly absorbed into the circulation from the gastrointestinal tract, and their bioavailability, unlike that of propranolol and metoprolol, is not significantly altered by whether the patient has recently eaten. Acebutolol is extensively metabolized by the liver, and elimination pathways involve approximately 30% to 40% through renal excretion and 50% to 60% by nonrenal mechanisms, including the bile and direct passage through the intestinal wall. The decreased hepatic metabolism and renal clearance rates seen in elderly patients may lead to the accumulation of both acebutolol and its metabolite, as has been reported with propranolol. In studies conducted to ascertain acebutolol's possible effect on common concurrently administered medications, the drug did not significantly alter either serum digoxin levels or serum insulin levels in diabetic patients treated with tolbutamide, nor did it change prothrombin time in patients treated with sodium warfarin.

Acebutolol↗

PubMed1985

Clonidine and guanfacine in hypertension.

Guanfacine, 1 to 3 mg/day, and clonidine, 0.1 to 0.3 mg twice a day, were compared in a 24-week double-blind, randomized, parallel study of 42 patients with hypertension that was inadequately treated by chlorthalidone, 25 mg/day. Mean reduction of blood pressure was 18/9 mm Hg after guanfacine and 14/8 mm Hg after clonidine. To determine the incidence of rebound hypertension, subjects were hospitalized for 7 days during chlorthalidone therapy for collection of baseline data and once again immediately after abrupt withdrawal of the alpha-agonist after 24 weeks of dosing. Although blood pressure and heart rate rose significantly in both groups, the changes after clonidine withdrawal were greater and occurred earlier (day 2) than those after guanfacine withdrawal (day 4). Forty percent of the subjects receiving guanfacine and 64% of subjects receiving clonidine had diastolic blood pressure elevations greater than or equal to 10 mm Hg from baseline. There were increases in urinary norepinephrine levels in both groups after drug withdrawal, but these correlated poorly with blood pressure rise. Side effects after guanfacine were much the same as those after clonidine. Guanfacine taken once a day provides an effective and safe alternative to clonidine in the management of essential hypertension.

Adult↗

PubMed1984

Effect of potassium chloride supplements on upper gastrointestinal mucosa.

Eight controlled 1- or 2-wk experiments involving 225 healthy male subjects and one study of 18 patients with hypertension, nine of whom were long-term users of a wax-matrix potassium chloride preparation, were conducted to evaluate the upper gastrointestinal safety of oral KCl supplements. All subjects in the short-term studies had normal upper gastrointestinal tracts. Subjects were examined again after at least 7 days of treatment with one of three commonly prescribed wax-matrix KCl tablets, KCl liquid, microencapsulated KCl, a potassium- sparer , or placebo. Some received an anticholinergic drug with treatment to induce delayed gastric motility. Diet and compliance to treatment regimens were controlled. Results indicate that upper mucosal injury, particularly erosions (43%) and ulcerations (11%), were more frequent after wax-matrix tablets. These changes occurred much less frequently after liquid KCl (0%), microencapsulated KCl (10.5% erosions, 1.2% ulcers), and the potassium-sparing drug (0%). More serious and more frequent lesions were associated with slowed motility. No occult bleeding was noted. Symptomatic complaints did not correlate with endoscopic findings. In the long-term study, patients with hypertension were examined endoscopically after 19 to 23 mo on KCl and again after 1 wk. Six of nine of the patients with hypertension treated for nearly 2 yr with a wax-matrix KCl supplement had significant lesions. One had developed ulceration after 7 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Delayed-Action Preparations↗

PubMed1984

Mucosal irritant potential of a potassium-sparing diuretic and of wax-matrix potassium chloride.

To measure their relative upper gastrointestinal irritant potential, either 5 mg amiloride and 50 mg hydrochlorothiazide (twice daily) or 24 mEq wax-matrix potassium chloride (three times a day) were given to 30 normal subjects with no prior endoscopic abnormalities in the esophagus, stomach, or duodenum. All subjects received glycopyrrolate, 2 mg (3 times a day) to slow gastric emptying. Repeat endoscopy after 7 days of treatment with wax-matrix potassium chloride revealed that 10 of 15 (67%) of the subjects developed one or more gradable upper gastrointestinal lesions (esophageal ulcer, gastric ulcer, eight cases of one or more mucosal erosions, and four cases of hyperemia or edema of the esophagus, stomach, or duodenum). Four subjects (27%) taking amiloride/hydrochlorothiazide developed either mild hyperemia or edema, but there were no erosions or ulcers in this group.

Amiloride↗

PubMed1984

Efficacy and safety of nitrendipine in patients with severe hypertension: a multiclinic study.

The efficacy and safety of nitrendipine in oral doses of 5-40 mg twice daily, alone or in combination with hydrochlorothiazide (50-150 mg/day) and/or propranolol (40-120 mg/day), were evaluated in an open study of 50 patients with severe hypertension with supine diastolic blood pressure (BP) greater than 115 mm Hg. Forty-six patients with an initial mean supine BP of 190/120 +/- 21/8 reached 151/95 +/- 15/6 mm Hg at visit 9, and 40 patients with a baseline BP of 188/120 +/- 21/9 achieved mean BP of 142/87 +/- 15/7 mm Hg at the end of therapy (visit 16). Thirty (75%) of these patients were normotensive: 9 (22%) on nitrendipine alone, 3 (7.5%) on nitrendipine and hydrochlorothiazide, 7 (17.5%) on nitrendipine and propranolol, and 11 (27.5%) on triple therapy. In nine responders to nitrendipine alone, mean BP was reduced from 187/119 to 143/84 mm Hg. Mean standing BPs were similarly decreased. Initially, heart rate increased slightly but decreased to baseline at the end of therapy. Side-effects were generally mild to moderate and were attributable to vasodilatory effects of the drug. Three patients required drug discontinuation because of adverse effects. Addition of propranolol and hydrochlorothiazide was well tolerated. Nitrendipine (20-40 mg twice daily) alone or in combination with propranolol and hydrochlorothiazide offers an alternative therapeutic approach in the management of severe hypertension.

Adult↗

PubMed1984

The effects of filling experimental large cortical defects with methylmethacrylate.

Three studies were performed using paired cadaver femurs to determine the effectiveness of filling large lytic defects of the femur with methylmethacrylate. In the first test, the paired femurs were prepared with a 2.5 cm defect in the femoral cortex. One of the paired femur defects was then filled with methylmethacrylate, while the other femur was left unfilled. The femurs were then tested in axial loading until failure. In the second test the paired femurs were prepared in the same manner and tested in torque until failure. In the third test, one of the paired femurs was prepared with a 2.5 cm defect and filled with methylmethacrylate while the other femur was left intact. When comparing those femurs whose defect was filled with methylmethacrylate to the prepared femurs that remained untreated, a significant increase in axial load strength of approximately 50% and an increase in torque strength of approximately 70% was found. It would seem that filling large lytic defects with methylmethacrylate at the time of internal fixation would significantly increase strength in both axial and torsional loadings.

Aged↗

PubMed1983

Vincristine neurotoxicity with residual equinocavus deformity in children with acute leukemia.

Vincristine has been demonstrated to be a neurotoxic agent with distal axonal degeneration progressing proximally. Five children with acute lymphoblastic leukemia developed bilateral peroneal nerve palsies with equinocavus deformities. Three developed fixed contractures requiring surgical correction. One patient was braced prior to development of fixed deformity and the other had physical therapy preventing fixed deformities and did not require surgery. All of the children obtained complete return of peroneal nerve function. Proper bracing and/or physical therapy at the time of diagnosis of neurologic deficit will prevent fixed contractures and the necessity for surgery.

Braces↗

PubMed1982

Upper gastrointestinal lesions after potassium chloride supplements: a controlled clinical trial.

The effects of a new microencapsulated potassium chloride formulation on upper gastrointestinal tract mucosa was compared with that of a popular wax-matrix formulation in 48 healthy volunteers. After a week of KCl, subjects were gastroscoped, the endoscopist being blind to the type of preparation taken. Wax-matrix formulations were associated with a higher incidence of upper gastrointestinal lesions. The lesions were not accompanied by epigastric symptoms. Glycopyrrolate, given to some volunteers to decrease gastric emptying, aggravated the effects of potassium chloride.

Acute Disease↗

PubMed1982

A simple controlled method for the clinical evaluation of antidiarrheal drugs.

A castor oil model induced diarrhea was used to evaluate dose regimens of the standard antidiarrheal polycarbophil. The study population consisted of 100 healthy volunteers, divided into five groups of 20 each, in whom diarrhea was induced by 120 ml flavored 36.4% castor oil. The polycarbophil dose regimens evaluated were 1, 1.5, 2, or 3 gm at 30-min intervals after castor oil to total the usual prescribed dose of 6 gm/day. One gram taken every 30 min for six doses lowered the number of bowel movements and also induced the least number of cramps and lowest cramp severity rating (reported by subjects). The same total dose over a different dosing interval was no more effective then placebo.

Acrylic Resins↗

PubMed1982

Hepatobiliary rickets.

Rickets secondary to hepatobiliary disease is a rare condition; however, the skeletal manifestations are similar to simple nutritional rickets. These skeletal changes include epiphyseal plate abnormalities, pseudofractures, bowing of long bones, scoliosis, and fractures. One-hundred and twelve charts and radiographs of patients with chronic hepatobiliary disease admitted to Children's Hospital of Michigan from 1968 to 1978 were reviewed. Nineteen, or 17%, of these patients showed roentgenographic evidence of rickets. Orthopedic management is primarily concerned with the treatment of fractures and prevention or correction of deformities in those children whose longevity justifies treatment.

Biliary Tract Diseases↗

PubMed1982

The natural history of metastatic synovial sarcoma: experience of the Southwest Oncology group.

Of 35 treated cases of metastatic synovial sarcoma, there was a slight male predominance (60%). The median age was 33 years, with 88% of the patients being white. The lower extremity was the most common primary site, occurring in 66% of the cases. The most common metastatic involvement was pulmonary (33 patients), with only three patients having lymph node involvement. The low incidence of lymph node involvement and the poor prognosis when positive lymph nodes are found suggest that prophylactic lymph node resection is unwarranted. The median time from evidence of metastases to death was ten months. The complete and partial response rate to chemotherapy in this series was 50%; however, duration of the response was rather short with recurrence of metastatic disease a median of seven months after response was first noted. The size of the primary lesion was greater than 5 cm in all but one of the cases. The local recurrence rate was 70% in those cases undergoing local resection and 30% in those cases in which local resection plus irradiation to the primary lesion was undertaken. No case in which radical resection of the primary tumor was undertaken had a local recurrence.

Adolescent↗