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Biomedical subjects

B Shapiro

Publications and source records attributed to B Shapiro.

At least 55 records · Page 3Linked to original sources
PubMed1998

Altered radiopharmaceutical distribution in myeloma: bone tracer in the heart and heart tracer in the bone.

Tissue deposits of amyloid may lead to various clinical symptoms and signs, depending on the site of deposition. In addition, a specific subtype of amyloidosis, AL protein type, is associated with multiple myeloma. Two cases representing contrasting examples of altered radiopharmaceutical biodistribution in myeloma and amyloidosis are presented and discussed, with a bone tracer depicting the heart and a heart tracer depicting the bones.

Aged↗
PubMed1998

Peak bone mass in young healthy men is correlated with the magnitude of endogenous growth hormone secretion.

GH plays a key role during adolescence in longitudinal bone growth and the attainment of peak bone mass. We explored the hypothesis that in early adulthood, bone mineral accretion and/or maintenance in men with normal GH and bone mineral status are related to the magnitude of endogenous GH secretion. Overnight plasma GH concentrations (sampled every 10 min from 2100-0500 h) were measured in 15 healthy, lean, Caucasian men (age, 24+/-1 yr; body mass index, 22.6+/-0.6 kg/m2; mean +/- SE). Total body, femur, and lumbar spine bone mineral mass/density were measured by dual energy x-ray absorptiometry. Total body and femoral bone mineral mass correlated with both total nocturnal GH and maximal GH concentrations even when bone mineral mass was adjusted by height (P = 0.005-0.02; r = 0.58-0.74). Neither spinal nor total body bone mineral density (BMD) correlated with GH. Maximum GH correlated with the BMD of all four femoral sites (P = 0.01-0.04; r = 0.55-0.66), whereas total nocturnal GH correlated with only one (trochanter; P = 0.01; r = 0.64) femoral site. Our data support the hypothesis that GH continues to play a role in the accretion and/or maintenance of bone mass in young men. This relationship is more evident in the bone mineral mass achieved than in the BMD.

Adult↗
PubMed1998

Bone mineral density and its change in pre-and perimenopausal white women: the Michigan Bone Health Study.

There is a need to better understand potential bone mineral density (BMD) loss during the menopausal transition since this period may include the initiation of interventions. The study purpose was to determine if there was BMD loss at the femoral neck, lumbar spine, or total body bone sites in a population-based study of women approaching or transitioning the midlife. The 583 enrollees were 25-45 years of age at the first of four annual measurements from 1992 through 1996. Bone mineral content and bone width were measured using dual-energy X-ray absorptiometry. Considering all enrollees collectively, there was a significant 3-year decline (1%) in BMD at the femoral neck over the 3-year period (p = 0.076). There was no significant annual change in the lumbar spine (p = 0.11), and a significant annual increase in the total body BMD (p = 0.0003). Within subgroups and cross-sectionally, BMD values of the femoral neck were 5% lower in women classified as perimenopausal compared with premenopausal enrollees; BMD was 3% and 1% lower at the lumbar spine and total body site, respectively. Longitudinally, among perimenopausal women, a double oophorectomy was associated with BMD loss in the spine (p = 0.0003), even though 75-85% of these women had a hormone replacement prescription at some time during the study period. In summary, the site with evidence of loss was the femoral neck, specifically among perimenopausal women. There was little evidence of substantial total body or lumbar spine BMD loss in premenopausal women with ovaries who maintained follicle-stimulating hormone levels < 20 mIU/l in the early follicular period. Double oophorectomy, even with hormone replacement, was associated with bone loss.

Absorptiometry, Photon↗
PubMed1998

Urinary ovarian and gonadotropin hormone levels in premenopausal women with low bone mass.

We hypothesized that lower ovarian and gonadotropin hormone concentrations would be associated with lower levels of peak bone mineral density (BMD) in apparently normally menstruating women who did not exercise intensively and did not report anorexia or bulimia. This hypothesis was evaluated using a case-with-control study design (n = 65) which was nested within a population-based longitudinal study of peak bone mass (Michigan Bone Health Study) with annual assessment in women aged 25-45 years (n = 582). Cases were 31 premenopausal women with BMD of the lumbar spine, femoral neck, and total body less than the 10th percentile of the distribution, where controls were 34 premenopausal women with BMD between the 50th and 75th percentile. BMD was measured by dual-energy X-ray absorptiometry. In addition to their annual measurement, these 65 participants collected first-voided morning urine specimens daily through two consecutive menstrual cycles. The urine from alternating days of this collection was analyzed for estrone-3-glucuronide (E1G), pregnanediol glucuronide (PdG), testosterone, and follicle-stimulating hormone by radioimmunoassay and these values adjusted for daily creatinine excretion levels. Additionally, analyses of daily urine specimens for luteinizing hormone (uLH) was undertaken to better characterize the possible uLH surge. Cases had significantly lower amounts of E1G (p = 0.009) and PdG (p = 0.002) than did controls, whether amounts were characterized by a mean value, the highest value, or the area under the curve, and after statistically controlling for body size. Further, when B-splines were used to fit lines to the E1G and PdG data across the menstrual cycle, the 95% confidence intervals (CIs) about the line for the controls consistently excluded and excluded and exceeded the 95% confidence bands for the cases in the time frame associated with the luteal phase in ovulatory cycles. Likewise, 95% CIs for the LH surge in controls exceeded the fitted line for cases around the time associates with the LH surge. The cases and controls were not different according to dietary intake (energy, protein, calcium), family history of osteoporosis, reproductive characteristics (parity, age at menarche, age of first pregnancy), follicular phase serum hormone levels, calciotropic hormone levels, or by evidence of perimenopause. We conclude that these healthy, menstruating women with BMD at the lowest 10th percentile from a population-based study had significantly lower urinary sex steroid hormone levels during the luteal phase of menstrual cycles as compared with hormone levels in premenopausal women with BMD between the 50th and 75th percentile of the same population-based study, even after considering the role of body size. These data suggest that subclinical decreases in circulating gonadal steroids may impair the attainment and/or maintenance of bone mass in otherwise reproductively normal women.

Absorptiometry, Photon↗
PubMed1998

Current concepts on the diagnostic use of MIBG in children.

Metaiodobenzylguanidine (MIBG) was developed 18 yr ago for scintigraphic imaging of the adrenomedullary tumors pheochromocytoma and neuroblastoma. Many studies have shown the usefulness of this agent for the management of patients with neuroblastoma or pheochromocytoma, and the 131I-labeled form was recently approved by the Food and Drug Administration for use in the U.S. This article summarizes our current concepts on the diagnostic use of MIBG in children. The radioisotopes available for labeling of MIBG and related compounds, the dosimetry, metabolism and mechanisms of uptake and retention are discussed. Our protocols for imaging both 131I-MIBG and 123I-MIBG, along with the normal distribution of these compounds, are reviewed. The use of MIBG for the management of neuroblastoma, and comparisons with other radiotracers available for imaging neuroblastomas are also addressed.

3-Iodobenzylguanidine↗
PubMed1998

Diagnostic evaluation of the adrenal incidentaloma: decision and cost-effectiveness analyses.

UNLABELLED: The goal of this study was to examine the clinical and economic outcomes of alternative diagnostic strategies for differentiating benign from malignant adrenal masses. METHODS: We used cost-effectiveness assessment derived from decision analysis and the economic perspective of the payer of health care services. One-time evaluation with fine-needle aspiration (FNA) and combinations of chemical-shift MRI, noncontrast CT, 131I-6beta-iodomethylnorcholesterol (NP-59) scintigraphy, with or without FNA, in a hypothetical cohort of 1000 patients with incidentally discovered unilateral, nonhypersecretory adrenal masses. We calculated and compared the diagnostic effectiveness, costs and cost-effectiveness of the alternative strategies based on estimates from published literature and institutional charge data. RESULTS: At an assumed baseline malignancy rate of 0.25, diagnostic utility varied from 0.31 (CT0) to 0.965 (NP-59) and diagnostic accuracy from 0.655 [noncontrast CT using a cut-off attenuation value of > or = 0 (CT0)] to 0.983 (NP-59). The average cost per patient per strategy ranged from $746 (NP-59) to $1745 (MRI +/- FNA). The best and worst potential cost-to-diagnostic utility ratios were 773 (NP-59) and 2839 (CT0) and 759 (NP-59) and 1982 (MRI +/- FNA) for cost and diagnostic accuracy, respectively. The NP-59 strategy was the optimal choice regardless of the expected outcome examined: cost, diagnostic utility, diagnostic accuracy or cost-effectiveness. Varying the prevalence of malignancy did not alter the cost-effectiveness advantage of NP-59 over the other diagnostic modalities. CONCLUSION: Based on available estimates of reimbursement costs and diagnostic test performance and using reasonable clinical assumptions, our results indicate that the NP-59 strategy is the most cost-effective diagnostic tool for evaluating adrenal incidentalomas over a wide range of malignancy rates and that additional clinical studies are warranted to confirm this cost-effectiveness advantage.

Adosterol↗
PubMed1998

Severe thyrotoxicosis due to functioning pulmonary metastases of well-differentiated thyroid cancer.

We report two cases of thyrotoxicosis resulting from hyperfunctioning lung metastases from differentiated thyroid cancer. In both patients, a simultaneous diagnosis of thyrotoxicosis and metastatic thyroid cancer was made, based on thyroid function tests as well as 131I whole-body scans showing low thyroid uptake of radioiodine and multiple foci of intense 131I uptake in the lungs. After total thyroidectomy (performed in Patient 2 only) and 131I therapy (cumulative dose of 12.3 GBq in Patient 1 and 9.6 GBq in Patient 2), there was a rapid clinical improvement with significant reduction of the pulmonary metastatic disease in both patients: Patient 1 became euthyroid, while Patient 2 became hypothyroid. Analysis of the 54 cases reported in the literature, including the 2 cases described here, shows this to be a very rare cause of thyrotoxicosis and one that can pose serious problems for both the diagnostic evaluation and choice of therapeutic strategy when compared with the much more common nonhyperfunctioning metastases from thyroid cancer. Lesser degrees of thyroid hormone secretion by differentiated thyroid cancer may be detected and exploited diagnostically by the chromatographic analysis of serum for endogenously labeled thyroid hormones after 131I administration.

Adenocarcinoma, Follicular↗
PubMed1998

Adrenocortical SPECT using iodine-131 NP-59.

Adrenal scintigraphy with 131I-labeled 6-beta-iodomethyl-19-norcholesterol (NP-59) is a technically demanding and complex procedure. However, it can provide crucial and unique information about the functional status of the adrenal glands and guide the appropriate therapeutic management of patients with biochemically proven disease. Since the introduction of this new investigational drug, scintigraphic imaging has been performed using conventional planar techniques. We present an interesting case of primary aldosteronism in which planar scintigraphy and SPECT were combined in an attempt to increase the sensitivity of the study. SPECT revealed scintigraphic evidence of bilateral adrenocortical hyperplasia. Interestingly, the CT scan of this patient showed only an equivocal abnormality in the left adrenal gland, suggestive of an adenoma.

Adosterol↗
PubMed1997

Diagnostic dilemma of small incidentally discovered adrenal masses: role for 131I-6beta-iodomethyl-norcholesterol scintigraphy.

Incidentally discovered adrenal masses are detected in 0.35% to 5. 00% of patients imaged with computed tomography (CT) for reasons other than suspected adrenal pathology. Most small adrenal masses are benign, although malignant tumors </= 3 cm in diameter are well described. In the setting of normal adrenal hormonal secretion, the preferential accumulation of 131I-6beta-iodomethyl-norcholesterol (NP59) by adrenocortical tissues allows the distinction of adenomas from other space-occupying or destructive lesions, with diagnostic images being obtained in 100% of lesions > 2 cm. Although some lesions </= 2 cm have yielded nondiagnostic images, the frequency of this phenomenon and thus the utility of NP59 scintigraphy for the evaluation of small adrenal lesions has remained incompletely characterized. Between January 1976 and December 1994 a total of 166 patients with nonhypersecretory unilateral adrenal masses </= 3 cm in maximal diameter, discovered incidentally during CT examinations of the abdomen or chest for reasons other than clinically suspected adrenal disease, were studied with NP59 scintigraphy. Nonhypersecretory masses </= 1 cm, > 1 to </= 2 cm, and > 2 to </= 3 cm yielded diagnostic images in 52%, 89%, and 100% of patients, respectively. Lesions other than adenomas, including malignancies, > 1 to </= 2 cm and > 2 to </= 3 cm were present in 9% and 10% of patients, respectively. These findings emphasize the need to determine the nature of small incidentally discovered adrenal masses whose management may alter patient care and confirm the utility of NP59 scintigraphy to evaluate nonhypersecretory adrenal masses regardless of size.

19-Iodocholesterol↗
PubMed1997

Abnormal Tl-201 myocardial scintigraphy associated with administration of sodium aurothiomalate.

A patient with strikingly reduced Tl-201 myocardial retention after intramuscular administration of gold therapy (sodium aurothiomalate) is described. Following a routine Bruce protocol exercise test, postexercise scintigraphy was normal; an abnormal scan of the thorax was obtained on delayed imaging at 3 hours. This scan showed no demonstrable myocardial retention of tracer. In between the two acquisitions, the patient received 50 mg intramuscular sodium aurothiomalate for rheumatoid arthritis. A repeat scan obtained 3 days later showed a normal myocardial scintigram. It is recommended that patients receiving intramuscular gold therapy should not undergo such treatment close to the timing of Tl-201 myocardial scans.

Antirheumatic Agents↗
PubMed1997

Scintigraphy of acute inflammatory lesions in rats with radiolabelled recombinant human interleukin-8.

We compared 125I-labelled recombinant human interleukin-8 (125I-IL-8) with 111In-labelled human leukocytes (111In-WBC) and 67Ga-citrate for scintigraphic depiction of acute sterile inflammatory lesions in rats. Radioiodination of IL-8 was catalysed by chloramine-T, and human leukocytes were radiolabelled with 111In-oxine. Inflammatory lesions were induced in male rats by subcutaneous injection of 2% carrageenan suspension into their left hindlimbs. Twenty-four hours later, each rat received 1.8-3.7 MBq (50-100 microCi) of a single agent by intravenous injection. Sequential whole-body scintigrams were obtained between 0 and 96 h post-injection. Activities in the lesion-bearing and control hindlimbs were expressed as regional percent injected activity corrected for physical decay (%IA) by reference to concurrently imaged standards, and for 125I-IL-8 by direct tissue counting at necropsy as well. 125I-IL-8 displayed appropriate electrophoretic mobility, retained chemotactic and high-affinity receptor-binding activity in vitro, and exhibited exponentially decreasing activity in most tissues beginning shortly after intravenous injection. Scintigrams showed asymmetrically increased activity in the lesion-bearing hindlimb for all three agents. By scintigraphy, 125I-IL-8 activity in the lesion-bearing hindlimb reached a zenith 1-3 h post-injection at 4.8 +/- 0.5 %IA and decreased exponentially thereafter, with little change in lesioned-to-control limb ratios (mean L/C = 3.0 +/- 0.7) over the imaging period. By direct tissue counting, abscess-associated mean IL-8 activity per gram of tissue increased to four times that of adjacent muscle and nearly seven times that of contralateral muscle by 24 h post-injection. Lesion-bearing hindlimb 111In-WBC activity also rose rapidly, reaching 4.2 +/- 0.6 %IA by scintigraphy at 3 h and an eventual plateau (maximum of 4.5 +/- 0.4 %IA) by 24 h. 67Ga scintigraphic activity in the lesion-bearing hindlimb peaked briefly at 3-6 h post-injection (9.2 +/- 0.5 %IA) and subsequently declined to a constant level of about 7.5 %IA. However, L/C for 111In-WBC and for 67Ga-citrate each averaged only 1.5 +/- 0.3 over the imaging period, compared with a mean L/C of 1.2 +/- 0.2 for a blood pool radiotracer. We conclude that 125I-IL-8 is rapidly and selectively concentrated in regions of acute inflammation, presumably by high-affinity binding to IL-8 receptors on neutrophils within the inflammatory focus. Radioiodinated IL-8 offers an attractive alternative to 67Ga-citrate and 111In-WBC for early imaging of acute inflammatory lesions, and demonstrates significantly higher target-to-nontarget activity ratios in this model. The potential usefulness of radiolabelled IL-8 for clinical scintigraphy should be evaluated.

Animals↗
PubMed1997

Intrapericardial paragangliomas (pheochromocytomas): imaging features.

OBJECTIVE: The imaging features of intrapericardial paragangliomas (pheochromocytomas) are described. MATERIALS AND METHODS: We conducted a retrospective study of the imaging features of all intrapericardial paragangliomas seen at our institution over the last 13 years. RESULTS: In this study, intrapericardial paragangliomas were typically located adjacent to or involved the left atrium. The diameter of the tumors ranged from 3 to 8 cm. Metaiodobenzylguanidine (MIBG) scintigraphy revealed 11 of 12 tumors (sensitivity = 92%). After MIBG scintigraphic location, dynamic contrast-enhanced CT revealed all 12 tumors. CONCLUSION: Intrapericardial paragangliomas are rare tumors, typically located adjacent to or involving the left atrium. For initial detection, regional location of these extraadrenal tumors, and detection of distant metastases, MIBG scintigraphy is recommended. Dynamic contrast-enhanced CT or MR imaging can then provide detailed anatomic delineation before surgical resection.

3-Iodobenzylguanidine↗
PubMed1997

Malignant paraganglioma of the prostate: case report, depiction by meta-iodobenzylguanidine scintigraphy and review of the literature.

OBJECTIVE: To describe the 123-I-MIBG scintigraphic, CT, MRI, operative and pathological findings in a case of malignant prostatic paraganglioma and to review the literature on this very rare tumor. EXPERIMENTAL DESIGN: Clinical imaging and pathological correlation of data in a referred patient. SETTING: Regional referral center and tertiary referral academic medical center. PATIENT: 17 year old man presenting with painless hematuria and a large prostatic mass. Interventions and measures. Renal ultrasound, transrectal ultrasound, ultrasound guided prostatic biopsy, pelvic CT and MRI, planar and SPECT 123-I-MIBG scintigraphy, and surgical exploration. RESULTS: The patient had a significant hydronephrosis of the left kidney and marked enlargement (120 ml) of the prostate gland by ultrasound. Ultrasound guided biopsies of the prostate and a left pelvic lymph node revealed a neuroendocrine tumor staining positive for chromogranin. CT and MRI revealed a large tumor of the prostate invading the seminal vesicles, bladder and rectum with extensive pelvic lymph node spread. The primary tumor and one of the nodes were shown to be 123-I-MIBG avid confirming the neuroendocrine nature of the tumor. The lesion was unresponsive to chemotherapy and unresectable at surgical exploration. CONCLUSIONS: To date there have only been 5 reports of prostatic paragangliomas. To our knowledge this is the first to have been studied by MIBG scintigraphy and like most paragangliomas it was MIBG-avid.

3-Iodobenzylguanidine↗