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Biomedical subjects

J R Ryan

Publications and source records attributed to J R Ryan.

At least 19 recordsLinked to original sources

Fine-needle aspirate of primary lymphoma of bone.

Primary lymphoma of bone (PLB) is a rare bone tumor. Fine-needle aspirates (FNA) were done on large destructive bone tumors from 2 elderly men, and both were initially read as inconclusive for malignancy because of scant cellularity. On retrospective study of the FNA slides after examining tissue histology, low numbers of diagnostic cells for lymphoma were recognized on the smears. There was extensive crush artifact, and most intact cells were stripped of their cytoplasm. In neither case was enough material harvested to make cell blocks or to perform special studies. Tissue histology disclosed abundant fibroconnective tissue stroma which probably made it difficult to acquire adequate FNA specimens. Another FNA done on a postoperative PLB tissue specimen disclosed similar features. Our experience in the 3 cases is consistent with the view that even though smears show scant cellularity, the diagnosis of PLB can at least be suggested by FNA. It is therefore important not to undercall the specimen because of low cellularity, and recommendation for tissue diagnosis can be given. This process is facilitated by a high index of suspicion based on clinical and radiographic findings.

Aged

Magnetic resonance imaging of massive bone allografts with histologic correlation.

OBJECTIVE: The objective of this study was to better understand the MRI appearance of massive bone allografts. DESIGN: The MRI findings of three massive bone allografts imaged in vivo were correlated with the histologic findings following removal of the allografts. A fourth allograft, never implanted, was imaged and evaluated histologically. PATIENTS: Allografts were placed for the treatment of primary or recurrent osteosarcoma. RESULTS AND CONCLUSIONS: The in-vivo allografts have a heterogeneous appearance on MRI which we attribute to the revascularization process. Fibrovascular connective tissue grows into the graft in a patchy, focal fashion, down the medullary canal from the graft-host junction and adjacent of the periosteum. The marrow spacers are initially devoid of normal cellular elements and occupied by fat and gelatinous material. This normal postoperative appearance of massive bone allografts must be interpreted as recurrent neoplasm or infection in the allograft. Recognition of these complications rests on features outside the marrow.

Bone Marrow

Acute myeloid leukaemia with t(8;16)(p11;p13) in a child after intrauterine X-ray exposure.

We describe t(8;16)(p11;p13) acute myeloid leukaemia (AML-M4) in a 12-year-old white male with a history of prenatal X-ray exposure. He had skin and bone involvement and some of the leukaemic blasts showed haemophagocytosis, characteristic features seen in t(8;16) AML. 20% of the reported cases of t(8;16)(p11;p13) AML are therapy-related and this case further supports the possible role of the ionizing radiation in the development of this disorder.

Adult

Primary embryonal rhabdomyosarcoma of long bone. Case report and review of the literature.

We report a case of primary embryonal rhabdomyosarcoma of long bone, presenting as a lytic destructive bone tumor in the right femoral diaphysis of a 7-year-old girl. To our knowledge, this is only the third report of this entity. The neoplasm was a pure embryonal rhabdomyosarcoma with numerous rhabdomyoblasts. Immunohistochemistry confirmed the diagnosis: The cells were reactive with antibodies directed against desmin, muscle-specific actin, and myoglobin. No other neoplastic mesenchymal component was present within the tumor. Although rare, primary rhabdomyosarcoma, along with Ewing's tumor and osteosarcoma, should be considered in the differential diagnosis of malignant bone tumors in childhood.

Actins

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

DNA content parameters of paraffin-embedded soft tissue sarcomas: optimization of retrieval technique and comparison to fresh tissue.

DNA content analysis of formalin fixed paraffin embedded (FFPE) tissue permits determination of the influence of DNA content on the prognosis in cohorts of patients for whom the clinical outcome is known. Of key importance in such an analysis is the accuracy of DNA content determination. Variations in the quality of DNA histograms from FFPE tissues of different types prompted a comparative evaluation of the preparative methodology of FFPE soft tissue sarcomas for DNA flow cytometry. Following deparaffination and rehydration of fixed tissue, and prior to fluorochrome staining, tissue blocks of 15 DNA aneuploid soft tissue sarcomas were subjected to repeated experimental (time x concentration) enzyme exposures. The goal of these studies was to define the optimal tissue specific retrieval technique with the coefficient of variation, maintenance of DNA aneuploidy, and DNA index as endpoints. After optimizing the technique, the DNA content of 50 soft tissue neoplasms derived from FFPE specimens was compared to the corresponding fresh surgical tissue. The observed 14 percent error rate in the determination of DNA ploidy status suggest limited utility for FFPE tissue in prospective therapeutic trials of soft tissue sarcoma.

Cell Count

Development and optimization of tissue preparative methodology for DNA content analysis of soft tissue neoplasms.

Data regarding DNA content parameters in soft tissue sarcoma is limited. Development and optimization of tissue specific preparative techniques for DNA flow cytometry was undertaken prior to routine DNA content analysis of soft tissue neoplasms; 154 soft tissue tumors were studied. Dissociation dependent differences in cellular yields, viabilities, maintenance of DNA aneuploid populations, coefficients of variation, and DNA index supported the need for these developmental studies. Fifty-six of eighty-nine patients had DNA aneuploid soft tissue sarcomas. A relationship between DNA aneuploidy and grade was seen in this series with 38% with low grade, 59% with moderate grade, and 69% with high grade tumors demonstrating DNA aneuploid populations (P < 0.005). The mean S-phase fraction for DNA diploid and aneuploid sarcomas was 7.2% and 13.3%, respectively (P < 0.001). When classified by histologic grade of the primary tumor, a greater percentage of metastatic lesions were DNA aneuploid (4 of 7 grade 2 lesions, and 15 of 16 grade 3 lesions). Decreases in cellular yields and rate of DNA aneuploidy were observed in a subgroup of patients with localized high grade sarcoma treated preoperatively, as compared to patients treated with initial surgery. Prospective correlation of DNA content parameters to prognosis and response to cytotoxic therapy are now possible and are ongoing.

Aneuploidy

Deletion of chromosome 13 in osteosarcoma secondary to irradiation.

The cytogenetic analysis of a radiation-induced osteosarcoma in a 31-year-old male is presented. Complex karyotypic changes with numerical and structural abnormalities, including a del(13)(q12.3q21.1), were observed. This deletion may indicate that loss of RB1 gene (locus in 13q14) may be involved in the development of radiation-induced osteosarcoma.

Adult

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

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

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

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

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

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

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