Search PubMed⌕ Search

Biomedical subjects

J R Ryan

Publications and source records attributed to J R Ryan.

At least 19 recordsLinked to original sources
PubMed1995

Scintigraphic evaluation of pancreatic transplants using technetium-99m-sestamibi.

UNLABELLED: The purpose of this study was to evaluate the feasibility of using 99mTc-sestamibi in the assessment of pancreatic transplant. METHODS: Ten transplant recipients with a history of insulin-dependent diabetes mellitus were studied. Fourteen 99mTc-sestamibi studies were performed. Each patient was injected intravenously with 10 mCi of 99mTc-sestamibi. Two-second frames were obtained for 1 min, followed by serial dynamic and static images every 5 min for 30 min. Technetium-99m sestamibi studies, read by two nuclear medicine physicians, were correlated with clinicopathologic findings and compared to the ten 201Tl studies obtained in seven of these patients. RESULTS: On 99mTc-sestamibi images, normally functioning grafts showed adequate perfusion on the angiogram and good uptake followed by clearance on static images. Time-activity curves showed an initial upslope followed by a downslope after the initial uptake peak. The quality of 99mTc-sestamibi images was superior to those of 201Tl in five, similar in four and marginally inferior in one paired study. Technetium-99m-sestamibi was used for both flow and static images, whereas a 99mTc radiotracer angiogram was needed to accompany the 201Tl study. CONCLUSION: Our preliminary experience indicates that 99mTc-sestamibi helps evaluate pancreatic transplants and provides high count statistics, which result in better image quality and diagnostic detail. Extensive quantitative studies are being performed to further evaluate this agent's role in the clinical management of pancreatic transplant patients.

Adult↗
PubMed1991

Antihypertensive effect of tiapamil from ambulatory and clinic methods.

Tiapamil (T), a calcium antagonist, was studied in hypertensive patients by 1) automatic monitor of blood pressure (AMBP), and 2) cuff and stethoscope clinic blood pressure (CBP). Systolic (SBP), diastolic (DBP) pressures and heart rate were measured. Patients (n = 58) received four weeks of placebos given twice daily. Baseline 24 h AMBP (wk 4), 147 +/- 18 (SBP) and 91 +/- 8 (DBP) mmHg; and CBP (wk 3 and 4), 152 +/- 16 (SBP) and 102 +/- 9 (DBP) were established. Then, patients received double-blinded therapy (wk 5-10) of twice daily tablets of placebo (n = 9); Level I T, 150-300 mg (n = 24); or Level II T, 450-600 mg (n = 25): i.e. 0 to 1,200 mg T/d. Significant responses, measured by AMBP (wk 10), were noted only at Level II T: SBP (-10.5 +/- 12.4) and DBP (-5.6 +/- 7.8) mmHg. However, CBP (wk 9 and 10) responded at Level I T (SBP, -7.7 +/- 12.4/DBP, -5.8 +/- 6.4) and Level II T (SBP, -8.8 +/- 9.4/DBP, -9.7 +/- 7.8 mmHg). There was minimal correlation (r = 0.16) of pressure responses to T measured by 24-h AMBP versus CBP methods. Therefore, T effectively lowered SBP and DBP, but individual responses measured by AMBP did not predict those measured by CBP. There was no effect of T on heart rate. Dizziness was noted in 12 percent of patients on T.

Adolescent↗
PubMed1989

Bone and soft-tissue lesions: diagnosis with combined H-1 MR imaging and P-31 MR spectroscopy.

The feasibility of combined magnetic resonance (MR) imaging and surface coil phosphorus-31 MR spectroscopy at 1.5 T was examined in a clinical study of 34 patients before biopsy of bone or soft-tissue lesions of the extremity and trunk. The results confirmed the inability of MR imaging alone to distinguish most benign lesions from malignant ones. Malignant lesions were distinguished from benign lesions on the basis of significantly higher mean peak ratios of phosphomonoester (PME) to beta-nucleoside triphosphate (NTP) and of phosphodiester to NTP, a significantly lower mean peak area ratio of phosphocreatine to NTP, and a higher mean pH. The diagnostic performance of the PME/NTP peak area ratio is characterized by a sensitivity (true-positive fraction) of 1.00 and a specificity (true-negative fraction) of 0.93. This study provided preliminary evidence that P-31 MR spectroscopy may be used to improve diagnostic specificity in bone and soft-tissue lesions.

Adolescent↗
PubMed1989

Comparison of the antihypertensive effects of betaxolol and chlorthalidone as monotherapy and in combination.

In this multicenter, double-blind, parallel study, the antihypertensive effects of betaxolol (20 mg once daily) and/or chlorthalidone (25 mg once daily) were analyzed in 186 patients with essential hypertension. Following a 2- to 4-week placebo baseline period, patients were randomized to one of two treatment groups (betaxolol or chlorthalidone) and studied for 6 weeks while receiving single therapy and an additional 6 weeks with a combination of the two agents. Significant decreases from baseline supine diastolic blood pressure (SDBP) were observed in both groups at the end of the single-therapy phase (11 mm Hg in SDBP for betaxolol and 12 mm Hg in SDBP for chlorthalidone); a further significant decrease (7 mm Hg for betaxolol and 8 mm Hg for chlorthalidone in SDBP) was observed from the end of the single-therapy phase to the end of the combination-therapy phase. Changes in supine systolic blood pressure (SSBP) from baseline to the end of the single-therapy phase were 10 mm Hg for the betaxolol and 16 mm Hg for the chlorthalidone group. In all cases, within-group changes were statistically significant. From the end of single therapy to end of combination therapy there was an additional 14-mm Hg and 13-mm Hg reduction in SSBP in the betaxolol and chlorthalidone groups, respectively. Overall, 89% of the randomized patients completed the single-treatment phase (phase I), and 89% of those patients completed the combined therapy phase (phase II). There was no significant difference between treatment groups in the clinical response rate (SDBP at or below 90 mm Hg or a decrease from baseline of at least 10 mm Hg). A substantial percentage of patients completing phase I responded to either single agent (58% for betaxolol and 65% for chlorthalidone). Among patients completing phase II therapy, the combination of the two agents produced a greater response rate (83% for the betaxolol-first group and 85% for the chlorthalidone-first group). In conclusion, both agents were effective and well tolerated. The most frequent adverse events in the single-therapy phase were headache, arthralgia, and dizziness, while bradycardia, rhinitis, arthralgia, and dizziness were most frequent in the combination-therapy phase. The combination of betaxolol (20 mg) and chlorthalidone (25 mg) once daily produced an additive antihypertensive effect regardless of which drug was administered first.

Betaxolol↗
PubMed1988

An acute dose-response pharmacodynamic evaluation of orally administered isradipine (PN-200-110) in hypertensive patients.

This study was conducted to assess acute oral dose-responses of four dose levels (2.5, 5, 10, 20 mg) of isradipine, a new calcium channel blocking agent of the 1,4-dihydropyridine group. Sixteen patients with mild essential hypertension were investigated using a randomized, four-way cross-over, double-blind, placebo-controlled design. After a 2-week washout period, all patients were admitted to a research unit where they entered a 3-day placebo equilibration, followed by 9 days of double-blind single doses of isradipine. Drug administration was randomized, and baseline blood pressure values obtained preceding active medication doses were fairly constant. Dose-related reductions in supine and in standing blood pressures were obtained. The mean peak supine blood pressure decrements to doses of 2.5, 5, 10, and 20 mg were 17/16, 25/19, 35/22, and 37/25 mm Hg, respectively. Pulse rates increased slightly. Similar responses were obtained with patients in the erect position. Peak hypotensive responses occurred within 3 hours after dosing. The duration of effect persisted as long as 21 hours, particularly after the 10- and 20-mg doses (15/9 and 17/12 mm Hg mean supine blood pressure decrements, respectively).

Antihypertensive Agents↗
PubMed1988

New face-bow simplifies routine use and dental laboratory cooperation.

The Spring-Bow instrument was selected for use by dental students at the Medical University of South Carolina College of Dental Medicine because its simplicity facilitates teaching and its versatility fosters continued routine use and cooperation with the dental laboratory. Rationale for this advanced Snow-type face-bow has been reviewed and advantages and disadvantages of the design have been discussed.

Dental Articulators↗
PubMed1988

A double-blind study of diflunisal and codeine compared with codeine or diflunisal alone in postoperative pain.

A double-blind, randomized, parallel-group study compared the analgesic efficacy of a single oral dose of 500 mg diflunisal, 60 mg codeine, 500 mg diflunisal plus 60 mg codeine given as separate agents, and placebo in 161 patients with moderate to severe postoperative pain. Standard subjective measures were used to evaluate analgesia. Eight-hour sum of pain intensity differences and total pain relief scores for all active treatments were significantly better than were those for placebo (p less than 0.05). Diflunisal plus codeine performed the best followed by diflunisal, codeine, and placebo. Diflunisal plus codeine was better than placebo from 1 1/2 to 8 hours (p less than 0.01), better than codeine from 1 1/2 to 6 hours (p less than 0.05), and better than diflunisal alone from 1/2 to 1 1/2 hours (p less than 0.05) for most measures of analgesia. Factorial analysis demonstrated a significant early codeine effect and a significant diflunisal effect throughout. No significant treatment group differences were observed regarding adverse effects. Our data demonstrate that diflunisal plus codeine is generally well tolerated and provides analgesia superior to that of diflunisal or codeine alone in the treatment of moderate to severe postoperative pain.

Adult↗
PubMed1988

Multicentric parotid cysts and cervical adenopathy in AIDS patients. A newly recognized entity: CT and MR manifestations.

Patients with AIDS or ARC may present with parotid gland enlargement either initially or during the course of their disease. Of nine such patients, eight had unilateral gland enlargement, and one had bilateral disease. CT and MR scanning revealed that all patients except one had bilateral multiple intraparotid cysts. In addition, four of the nine patients clinically had cervical adenopathy, while all patients had adenopathy on scanning. We believe that the association of parotid cysts and cervical adenopathy is another manifestation of AIDS or ARC and, when found on scanning, should alert the clinician to the probable underlying condition.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Salivary gland lymph nodes. The site of lymphadenopathies and lymphomas associated with human immunodeficiency virus infection.

Normally, lymph nodes are intimately associated with the salivary glands, particularly the parotid gland. Several lymph nodes are embedded in the parotid gland, other lymph nodes are adjacent to the submaxillary gland, and ectopic salivary gland acini and ducts are commonly present in cervical lymph nodes. These salivary gland lymph nodes may become the primary site of the benign lymphadenopathy and the malignant lymphomas characteristically associated with human immunodeficiency virus (HIV) infection. This report of a series of HIV-associated lymphatic lesions originating in salivary gland lymph nodes comprises nine cases of salivary gland masses that were surgically excised, it includes six cases of lymphadenitides and three cases of lymphoma--all originating in salivary gland lymph nodes and showing the histologic lesions known to occur in association with the acquired immunodeficiency syndrome. The HIV-related infections and neoplasias located in the salivary gland lymph nodes raise interesting questions about the possible etiologic role of an oral portal of entry and of the virus-infected saliva. The recognition of their clinical and pathologic features is indispensable to enable correct diagnosis and treatment.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Nabumetone kinetics in the young and elderly.

Nabumetone, a nonsteroidal anti-inflammatory drug of the naphthylalkanone class, was studied in an open-label fashion to compare the relative single-dose and steady-state kinetics in young healthy male volunteers and in elderly patients with degenerative joint disease. Seventeen healthy male volunteers 21 to 30 years of age and 17 patients 60 to 75 years of age were studied. After a single oral dose of 1,000 mg nabumetone, blood and urine samples were collected over a five-day period. Plasma was assayed for nabumetone and the active metabolite, 6-methoxynaphthylacetic acid, and the urine was assayed for five metabolites. Following this phase, they received daily oral doses of 1,000 mg nabumetone for 14 days. After the final dose, blood and urine samples were again collected for five days for the same assays. These data were fitted to a single compartment model and the derived data are as follows: mean maximal plasma concentration, maximal time concentration, area under the plasma-time curve, elimination rate constant, and elimination half-life in the young group after single dose were 22.9, 8.4, 838, 0.032, and 21.2, respectively, whereas on steady-state, values were 33.6, 4.1, 666, 0.031, and 22.1, respectively. In the elderly group after single dose, these values were 30.2, 10.8, 1,538, 0.024, and 29.2, whereas on steady-state, they were 50.0, 7.2, 1,092, 0.027, and 25.6. The accumulation ratio was 1.6 in the young and 1.8 in the elderly. Side effects in the young were mild and consistent of headaches, epigastric discomfort, nausea, and vomiting, whereas in the elderly they consisted mainly of headaches. No significant changes in complete blood cell count, blood chemistries, or urinalysis were noted. We concluded from these data that the drug does not accumulate if given every 24 hours; therefore, a single daily dose should provide sufficient therapy and that due to a difference in elimination, elderly patients may require a lower dose.

Adult↗
PubMed1987

Role of misoprostol in reducing aspirin-induced gastrointestinal blood loss in arthritic patients.

Nonsteroidal anti-inflammatory drugs are used to control pain and inflammation in arthritic disorders. When used at recommended anti-inflammatory dose levels, however, they often produce injury to the gastric and duodenal mucosa and concomitant blood loss. A double-blind, parallel, placebo-controlled study was conducted to assess the effectiveness of misoprostol, a synthetic analogue of prostaglandin E1, in preventing gastrointestinal blood loss induced by acetylsalicylic acid in patients with degenerative joint disease. Forty-five arthritic patients (22 women and 23 men) were admitted to the study. All patients had received treatment with 3,900 mg of acetylsalicylic acid per day in four divided doses for at least two weeks and continued to receive that regimen for the duration of the study. Red blood cells were tagged with chromium-51, and fecal blood loss was determined from Days 4 to 7. Patients with a mean blood loss of at least 1.5 ml per day were randomly allocated to receive either placebo or 200 micrograms of misoprostol four times daily for seven days. Fecal blood loss was measured daily, and the results were compared with baseline determinations. Of 41 patients who completed the study, 19 were treated with misoprostol. Of these, 11 patients (57.9 percent) had at least a 50 percent reduction in blood loss. Of 22 patients receiving placebo, only one had a 50 percent reduction in blood loss (p = 0.003; Fisher's exact test). Mean blood loss in patients using misoprostol was reduced from 3.65 +/- 2.51 to 1.57 +/- 0.86 ml per day, whereas among those taking placebo, mean blood loss did not significantly change (2.98 +/- 1.24 to 2.79 +/- 1.63 ml per day). The difference in blood loss between the misoprostol and placebo groups was significant (p = 0.0023; Wilcoxon test). In those patients who completed the study, no significant changes were detected on laboratory tests. In conclusion, misoprostol effectively reduced fecal blood loss in arthritic patients treated with acetylsalicylic acid.

Alprostadil↗
PubMed1987

Enteric coating of fenoprofen calcium reduces gastrointestinal microbleeding.

The effects of plain and enteric-coated fenoprofen calcium (Nalfon, Dista, Indianapolis, Ind.) on gastrointestinal microbleeding were studied in 32 normal male volunteers in a randomized, open-label, parallel trial at two inpatient research facilities. A 1-week placebo (baseline) period preceded 2 weeks of fenoprofen therapy (enteric coated or plain, 600 mg q.i.d.). Fecal blood loss was measured by 51Cr-tagged erythrocyte assay and averaged over days 4 to 7 (baseline) and 11 to 14 and 18 to 21 (active therapy). At one center gastrointestinal irritation was evaluated endoscopically before and after active therapy. Endoscopy showed both formulations to cause mucosal damage not evident by subject-reported symptoms. Four of the 16 subjects developed asymptomatic duodenal ulcers. Mean daily fecal blood loss was significantly lower (P = 0.03) with enteric-coated (mean +/- SD, 1.104 +/- 0.961 ml/day) than with plain fenoprofen calcium (mean +/- SD, 1.686 +/- 0.858 ml/day), suggesting that tolerance of fenoprofen can be improved with administration in an enteric-coated form.

Adult↗
PubMed1987

The effect of various dose regimens of famotidine on basal nocturnal and meal-stimulated gastric secretion.

The antisecretory profile of the H2-receptor antagonist famotidine was studied with various oral doses and regimens in 10 healthy volunteers with high basal acid output (greater than or equal to 5 mEq/hr). Doses included 10, 20, and 40 mg at 9 PM and 9 AM and also 40 mg at 9 PM only. In the 22 hours after the PM doses, overnight (midnight to 7 AM) basal acid secretion was evaluated. Daytime meal-stimulated secretion was assessed at 7 AM, 12 noon, and 5 PM. Doses of 10, 20, and 40 mg inhibited fasting nocturnal basal secretion by 69%, 86%, and 83% to 94%, respectively (P less than 0.01). Meal-stimulated secretion at 7 AM (10 hours after administration) was inhibited by 28% and 39% (P less than 0.01) by only the 40 mg doses. The response to the 12 noon meal was inhibited by the 9 AM doses of 10, 20, and 40 mg by 45%, 75%, and 85%, respectively (P less than 0.01). The effect of a 40 mg dose given at 9 PM only had dissipated by breakfast (7 AM). The response to the 5 PM meal was suppressed by the 20 and 40 mg doses given at 9 AM by 22% and 35%, respectively (P less than 0.05). Suppression was present in only eight of the subjects after the 20 mg dose but in all 10 after the 40 mg dose. The effect on basal gastric aspirate pH values paralleled those seen on acid output. An association was found between mean plasma concentrations of famotidine and mean inhibition of meal-stimulated acid secretion. However, individual values may not be predictive.

Adult↗
PubMed1987

Absence of disulfiram-type reactions to single and multiple doses of cefonicid: a placebo-controlled study.

Disulfiram-type reactions after ingestion of alcohol have been reported in patients treated with a number of cephalosporin antibiotics; predominantly with agents containing the methylthiotetrazole side chain, although other similar configurations have also been implicated. Since cefonicid has a sulphonic acid thiotetrazole substitution, we investigated the possibility of a cefonicid-ethanol interaction in 15 healthy volunteers. During the first two crossover phases of the study, single 1 g doses of cefonicid followed by ethanol challenges were compared to placebo followed by ethanol challenges. In the third phase, all volunteers received three consecutive 1 g doses of cefonicid given at 24 h intervals followed by an ethanol challenge. At no time did any of the subjects experience a disulfiram-type reaction, and their blood aldehyde concentrations did not increase throughout the study.

Acetaldehyde↗
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↗