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Biomedical subjects

M M Hammami

Publications and source records attributed to M M Hammami.

34 records · Page 2Linked to original sources
PubMed1996

Immunoreactive endothelin-1, endothelin-2 and big endothelin-1 in follicular fluids of women undergoing ovulation induction for in-vitro fertilization.

Endothelin-like immunoreactivity specific for endothelin-1 (ET-1), endothelin-2 (ET-2) or big endothelin-1 (big ET-1) was measured, using commercially available radioimmunoassay kits, in follicular fluid collected at the time of oocyte aspiration from 36 women undergoing ovulation induction by human menopausal gonadotrophin (HMG). The relationship of ET concentrations to HMG dose, peak serum oestradiol concentration, the number and size of follicles (by ultrasound), the number of retrieved oocytes and the fertilization rate per retrieved oocyte were studied. Overall, 94% of follicular fluid samples were positive for ET-1, 92% were positive for ET-2, and 100% were positive for big ET-1. Mean ET-1, ET-2 and big ET-1 concentrations were 17.23 +/- 12.20, 32.42 +/- 14.32 and 34.55 +/- 16.34 pg/ml respectively. Endothelin-like immunoreactivity in follicular fluid samples was found in an order of ET-1 < ET-2 < big ET-1. There was a highly significant positive correlation (r = 0.8711,P = 0.001, n = 32) between follicular ET-1 and ET-2 concentrations. No significant correlation of follicular big ET-1 was established either with ET-1 or ET-2. However, big ET-1 was found to be negatively correlated with number of oocytes (P = 0.03) and number of follicles (P = 0.04). Control plasma ET-1 and follicular ET-1 were not significantly different. There was no significant correlation between ET concentrations and any of the other studied parameters. The results demonstrated that immunoreactive ET-1, ET-2 and big ET-1 exist in human follicular fluid collected at the time of oocytes retrieval for in-vitro fertilization and may be involved in the regulation of reproductive function. The clinical significance and physiological role of follicular fluid ET deserve further studies.

Adult↗
PubMed1996

False-positive radioiodine uptake in the abdomen and the pelvis: radioiodine retention in the kidneys and review of the literature.

Because the kidneys are usually not visualized on radioiodine whole-body scans, the renal uptake can be mistaken for a thyroid cancer metastasis. The authors report the prevalence and characteristics of radioiodine retention in the kidneys and review the reported causes of false-positive radioiodine uptake in the abdomen and pelvic areas. Radioiodine uptake in the renal bed was noted on 9 of 400 (2.2%) I-123 diagnostic whole-body scans performed over a 7-month period in our center. The uptake was noted more clearly on posterior views, cleared on delayed images after further hydration, and was not consistently present on follow-up scans. It was unilateral and mimicked a renal or adrenal metastasis in 44% of the scans. In three cases, the uptake was associated with a dilated calyx, an extrarenal pelvis, or a voluminous pelvis. False-positive radioiodine uptake in the abdomen and pelvis has been previously reported in association with 14 different conditions. However, renal retention may represent the most common cause of false-positive radioiodine uptake in the abdomen pelvis. Delayed imaging after additional hydration is usually sufficient to clarify its origin.

Abdomen↗
PubMed1996

Evidence for endothelial cell activation/injury in heatstroke.

OBJECTIVES: We treated the hypothesis that heatstroke is associated with endothelial cell activation/injury and examined the possibility that the markers of endothelial cell activation/injury may be associated with its severity and complications such as disseminated intravascular coagulation, lung injury, and renal dysfunction. DESIGN: Prospective analyses. SETTING: Heatstroke Center in Makkah, Saudi Arabia. PATIENTS: Twenty-two adult patients with heatstroke. INTERVENTIONS: The plasma concentration of endothelin, circulating intercellular adhesion molecule-1 (ICAM-1), and von Willebrand factor-antigen values were measured, respectively, by radioimmunoassay, enzyme-linked immunosorbent assay, and rocket electroimmunoassay, in heatstroke patients on admission (precooling) and after complete cooling (postcooling), and in ten normal control patients. MEASUREMENTS AND MAIN RESULTS: Precooling heatstroke patients (rectal temperature 40.9 +/- 1.1 [SD] degrees C) had increased circulating concentrations of endothelin, c-ICAM-1, and von Willebrand factor-antigen in 100%, 80%, and 77% of patients to 126.4 +/- 11.2 pmol/L, 523.1 +/- 154.4 ng/mL, and 3.85 +/- 2.3 U/mL, respectively (control values: 13.7 +/- 4.2 pmol/L [p < .001]; 247.4 +/- 68.2 ng/ml [p < .001]; and < 1.5 U/mL, respectively). There was a significant (r2 = .68, p < .01) correlation between circulating ICAM-1 and endothelin concentrations. Plasma endothelin concentration correlated negatively with temperature (r2 = .35, p < .05). Mean endothelin concentration was similar in patients with or without renal dysfunction, and mean von Willebrand factor-antigen concentration was similar in patients with or without lung injury or disseminated intravascular coagulation. There were no significant correlations between circulating ICAM-1, endothelin, or von Willebrand factor-antigen concentration and the Simplified Acute Physiology core. After cooling, mean circulating ICAM-1 and endothelin concentrations decreased significantly to 400 +/- 109 ng/mL and 93 +/- 38.5 pmol/L, respectively, whereas the mean von Willebrand factor-antigen concentration increased to 5.55 +/- 2.18 U/mL (p > .05). CONCLUSIONS: Our findings of increased circulating concentrations of circulating ICAM-1, endothelin, and von Willebrand factor-antigen are consistent with the hypothesis that heatstroke is associated with endothelial cell activation/injury. Whether the endothelial cell activation/injury is implicated in the pathophysiology of this disorder merits further studies.

Adult↗
PubMed1996

Radioiodine breast uptake in nonbreastfeeding women: clinical and scintigraphic characteristics.

UNLABELLED: We studied the scintigraphic and associated clinical characteristics of radioiodine breast uptake in nonbreastfeeding thyroid cancer patients undergoing routine whole-body radioiodine scanning. METHODS: We performed a retrospective review of the radioiodine scans and medical records of 30 prospectively collected cases. RESULTS: Twenty-three nonpregnant patients had discontinued breastfeeding for a mean of 11.4 mo. Three postmenopausal and four single nulliparous patients had radioiodine breast uptake on one or more occasions. This represented about 6% of all female patients who had radioiodine scans over a 3-yr period. Four patterns of uptake, full, focal, crescentic and irregular, were observed. Breast uptake mimicked lung metastasis in nine patients. Expressible galactorrhea and moderately elevated prolactin levels were present in 48% and 24%, respectively, of patients examined. In 14 patients followed for an average of 11.4 mo, there were no consistent changes in the pattern or intensity of breast uptake. In 18 patients who had both 123I diagnostic and 131I postablation scans within a few days, breast uptake was present on both scans in 75%. In four patients, breast uptake was present, despite the 4%-9% radioiodine uptake by the thyroid; in one patient, iodinated contrast material blocked the uptake of the thyroid gland but not of the breast. CONCLUSION: Although the mechanisms of radioiodine breast uptake remain unclear, breast uptake should be suspected in all female patients with radioiodine uptake in the chest area, even in the absence of a history of breastfeeding.

Adult↗
PubMed1996

Isolated porta hepatis metastasis of papillary thyroid cancer.

Metastases from differentiated thyroid cancer are usually seen in the cervical or mediastinal lymph nodes, lung or bone. We report a case of papillary thyroid cancer metastasizing to lymph nodes in the porta hepatis. No other site of metastasis was apparent on neck or abdominal exploration or on iodine whole-body scans. The primary tumor was a multifocal papillary thyroid cancer arising on a background of multinodular goiter. The metastasis was observed on a diagnostic radioiodine scan after surgical resection of the primary tumor despite significant (11%) radioiodine uptake by residual thyroid tissue in the neck and was proven by histologic examination and thyroglobulin immunohistochemistry. Although rare, metastasis to porta hepatis lymph nodes should be considered in the differential diagnosis of abdominal radioiodine uptake in patients with differentiated thyroid cancer.

Adult↗
PubMed1996

Activation of coagulation and fibrinolysis in heatstroke.

Hemorrhagic diathesis and widespread microthrombosis are common in heatstroke. To assess the early stages of coagulopathy in heatstroke, thrombin-antithrombin III (TAT), fibrin monomers, plasmin-alpha 2-antiplasmin (PAP), plasminogen and D-Dimer were measured in 16 heatstroke patients (means +/- SE rectal temperature 42.3 +/- 0.2 degrees C) pre- and postcooling and compared with 8 heatstressed and 23 normal controls. Comparing heatstroke patients with normal controls, TAT, fibrin monomers, PAP and D-Dimer were elevated to (median (range)) 16.5 (4-1000) versus 3.5 (2-7.2) micrograms/l p < 0.001, 16 (4-113) versus 2 (2-9) nM p < 0.001; 3300 (1000-36500) versus 255 (136-462) micrograms/l p < 0.001 and 0.72 (0.22-64.8) versus 0.15 (0.05-0.25) microgram/ml p < 0.01 respectively. Plasminogen decreased to 81% (34-106); PAP, TAT and D-Dimer correlated significantly with hyperthermia (r = 0.577, p = 0.02; r = 0.635, p = 0.01; r = 0.76, p = 0.003). Postcooling PAP decreased to 545 (260-850) micrograms/l p < 0.005, TAT 10 (6-70) micrograms/l, and fibrin monomers 22 (18-86) nM remained unchanged. Heatstressed controls showed mild but significant increase in all markers. Activation of coagulation and fibrinolysis occurs early and is profound and sustained in heatstroke. Cooling seems to attenuate the activation of fibrinolysis only, however, this requires confirmation in a larger study population.

Aged↗
PubMed1994

Patterns of radioiodine uptake by the lactating breast.

Breast uptake of radioiodine, if not suspected, may be misinterpreted as thyroid cancer metastasis to the lung. To characterize the patterns of radioiodine breast uptake, we retrospectively studied 20 radioiodine scans that were performed within 1 week of cessation of breast feeding. Four patterns of uptake were identified: "full", "focal", "crescent" and "irregular". The uptake was asymmetric in 60% (left > right in 45%, right > left in 15%), symmetric in 25% and unilateral in 15% of cases. A characteristic full bilateral uptake was present in 40% of cases. In three cases with the irregular pattern, caused in part by external contamination with radioactive milk, the uptake closely mimicked lung metastases. Delayed images, obtained in one case, showed an apparent radioiodine shift from the breast to the thyroid, suggesting that the presence of breast uptake can modulate radioiodine uptake by thyroid tissue. In a case of unilateral breast uptake, a history of mastitis was obtained, which to our knowledge has not been previously reported. Breast uptake of radioiodine may take several scintigraphic patterns that are not always characteristic of the lactating breast and may affect the apparent extent of thyroid remnant/metastasis.

Adult↗
PubMed1994

False-positive radioiodine whole-body scan in thyroid cancer patients due to unrelated pathology.

Radioiodine whole-body scanning is the imaging modality of the highest accuracy in diagnosing metastases from differentiated thyroid cancer. However, unrelated pathology in one of several nonthyroidal tissues that normally take-up/secrete radioiodine may result in a false positive scan. The authors report cases of an ectopic kidney, chronic sinusitis, dacryocystitis, and an artificial eye, complicating differentiated thyroid cancer, that on radioiodine scanning mimicked lumbar, frontal, and left and right orbital bone metastases, respectively. The nature of the radioiodine uptake was suspected from the results of a bone scan and proven by ultrasound (ectopic kidney), by reimaging after specific treatment (chronic sinusitis, and dacryocystitis), or by postwashing reimaging (artificial eye). To our knowledge, this is the first report of such cases. Nonthyroidal pathology should be excluded before exposing patients with apparent thyroid cancer metastases that have atypical characteristics on radioiodine whole body imaging.

Adult↗
PubMed1994

The level of endothelin-like immunoreactivity in seminal fluid correlates positively with semen volume and negatively with plasma gonadotrophin levels.

OBJECTIVE: The newly discovered vasoactive peptides, endothelin 1, 2 and 3, and their receptors are widely distributed in various non-vascular tissues. Recent studies have suggested the presence, as well as possible regulatory roles, of endothelins at several levels of the pituitary-gonadal axis. We determined the level of endothelin-like immunoreactivity in the seminal fluid and examined its possible correlation with routine semen parameters or plasma levels of FSH, LH or testosterone. DESIGN: Prospective study in a tertiary care centre. PATIENTS: Ninety-one men attending infertility clinics for male factor, female factor or both. MEASUREMENTS: Endothelin-like immunoreactivity was determined in seminal fluid using two radioimunoassays, ET1-21 that measures endothelin and ET-1,2 that measures both endothelin and big endothelin. In addition, the levels of FSH, LH and testosterone as well as routine semen parameters were determined. RESULTS: Sperm density ranged from 0 to 315 x 10(6) with a mean (+/- SD) of 28.5 x 10(6) (+/- 48 x 10(6)) sperm/ml and the percentage of motile sperm ranged from 0 to 85% with a mean of 16% (+/- 20.5%). Mean levels of FSH (n = 33), LH (n = 35) and testosterone (n = 35) were 6.4 +/- 4.9 IU/l, 3.5 +/- 2.8 IU/l and 21 +/- 9.4 nmol/l, respectively. Mean ET1-21 level (n = 91) was 81 +/- 16.5 pmol/l, and mean ET-1,2 level (n = 33) was 630.5 +/- 143 pmol/l. There were significant correlations between the levels of ET1-21 and ET-1,2 (r = 0.37, P = 0.04), ET1-21 and FSH (r = -0.5, P = 0.006), ET1-21 and LH (r = -0.46, P = 0.01), and ET1-21 level and semen volume (r = 0.23, P = 0.03). Mean level of ET1-21 or ET-1,2 was significantly lower in patients treated empirically with clomiphene citrate or gonadotrophins (n = 34) compared to untreated (n = 52) patients (P = 0.04). CONCLUSIONS: We conclude that in human seminal fluid (1) endothelin-like immunoreactivity that is specific for active endothelin (ET1-21) represents about 13% of the total immunoreactivity; (2) inactive big endothelin or its N-terminal derivative(s) may account for most of the immunoreactivity; (3) the production/secretion of endothelin may be inhibited by LH and/or FSH; and (4) endothelin level correlates positively with seminal fluid volume.

Endothelins↗
PubMed1993

False-positive thyroid cancer metastasis on whole-body radioiodine scanning due to retained radioactivity in the oesophagus.

In patients with differentiated thyroid cancer, radioiodine uptake in the mediastinal area most often indicates thyroid cancer metastasis. We review 15 radioiodine whole-body scans showing 19 mediastinal artefacts that mimicked lymph node or spinal metastasis. The artefacts disappeared on delayed images after eating and drinking (17) or on studies repeated within 1 week (2), suggesting their oesophageal origin. No patient had clinical oesophageal or gastric disease. Only two artefacts were linear; 12 were focal and five were diffuse. Twelve artefacts were better seen on anterior views (nine in the upper, two in the middle and one in the lower mediastinal area), whereas seven were better seen on posterior views (two in the upper, two in the middle, and three in the lower mediastinal area). The 15 scans were identified from about 1000 scans performed over 24 months in our centre. We conclude that the transient presence of radioiodine in an apparently normal oesophagus may not uncommonly mimic mediastinal lymph node or spinal metastases from thyroid cancer and that its scintigraphic presentation is variable.

Adult↗
PubMed1993

Spurious thyroid cancer bone metastases on radioiodine scan due to external contamination.

In patients with differentiated thyroid cancer, bone uptake on radioiodine whole body scan indicates functional metastasis and is usually followed by treatment with a high dose of 131I. However, apparent radioiodine uptake in the bone may be due to other causes. We describe 19 radioiodine artifacts that mimicked bone metastases and were proven to be due to external contamination as they disappeared on reimaging after skin cleaning and garment change (15 artifacts) or on a repeat study (four artifacts). All artifacts were noted only on anterior views; 12 in the skull, five in the shoulder girdle and two in the upper extremity. Thirteen artifacts were focal and six were smeared. The prevalence of scans showing such artifacts was 0.5% of the total number of radioiodine scans performed over a 3-year period. Distinguishing contamination artifacts from real bone metastases based on scintigraphic appearance is rather difficult. Repeat post-cleaning images should be obtained in all newly identified cases of apparent bone metastasis.

Adult↗
PubMed1993

Spurious lung metastases on radioiodine thyroid and whole body imaging.

In patients with differentiated thyroid cancer, radioiodine uptake in the area of the lung usually denotes metastasis; however, it could represent an uptake by unrelated pulmonary disease or by the breasts, or external contamination. In this study, 22 foci that simulated lung metastasis on 11 thyroid and whole body scans were proven not to be metastasis by reimaging after cleaning (15 foci), or were strongly suspected to be due to external contamination because of the features of other images (7 foci). All foci were noted only on anterior views of the chest. Of the 22 foci, 19 were focal, two were smeared, and one was lobar. Foci were multiple in 7 scans, unilateral in 10 scans, and were associated with other artifacts in 4 scans. Caution should be used in interpreting apparent pulmonary radioiodine uptake as lung metastasis; reimaging after cleaning the skin and changing garment should be obtained when the uptake is confined to anterior views of the chest and/or when its pattern is atypical.

Adult↗
PubMed1991

Regulation of 11 beta-hydroxysteroid dehydrogenase activity in human skin fibroblasts: enzymatic modulation of glucocorticoid action.

The regulation of 11 beta-hydroxysteroid dehydrogenase (11 beta HSD) was studied in cultured human skin fibroblasts. 11-Oxo-reductase activity was 5- to 10-fold higher than 11 beta-dehydrogenase activity. Cells treated with 100 nM dexamethasone (Dex) showed a 3-fold increase in the maximum velocity of both activities without a change in the Km values. Dex induction of 11 beta HSD was half-maximal at 48 h and was blocked by glucocorticoid receptor antagonists. Nonglucocorticoid steroids were ineffective. Removal of serum from the culture medium increased maximum velocity values up to 6-fold. Treatment of cells grown in the absence of serum with 8-bromo-cAMP, phorbol esters, or insulin decreased both 11 beta HSD activities. The effects of Dex treatment and serum removal were additive and were blocked by cycloheximide and actinomycin-D. In all experiments both 11 beta HSD activities were modulated in parallel. Both cortisone (200 nM) and cortisol increased the aromatase activity of fibroblasts in the presence of serum. Prior induction of 11 beta HSD by serum removal increased the potency of cortisone from 10-15% to 50% that of cortisol. We conclude that 1) in human fibroblasts 11 beta HSD appears to be a single protein that is under multifactorial regulation; 2) 11 beta HSD may increase or decrease cortisol availability to glucocorticoid receptors; and 3) plasma cortisone levels may be important in assessing glucocorticoid status.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMedDate not supplied

Hormonal evaluation in idiopathic oligozoospermia: correlation with response to clomiphene citrate therapy and sperm motility.

The reported response of sperm count to clomiphene citrate therapy in subfertile males with idiopathic oligozoospermia has been widely variable. The author postulates that this may be due in part to patient heterogeneity that may be reflected in pretreatment hormonal status. Seventeen patients with idiopathic oligozoospermia (mean +/- SE sperm density of 7.3 +/- 1.2 x 10(6) sperm/mL, mean FSH of 5 +/- 0.5 IU/L) were studied. Pretreatment basal LH, FSH, testosterone, free T4, and prolactin levels as well as LHRH-stimulated LH and FSH levels were examined in relation to pretreatment semen parameters and percent change in sperm count after a mean of 7.2 +/- 0.6 months of clomiphene citrate therapy. The percentage of motile sperm correlated with basal LH (r = .59, p = .02, n = 16) and free T4 levels (r = .62, p = .02, n = 13). Clomiphene citrate therapy was associated with a significant increase in total sperm count (mean percent change 261 +/- 117, p = .02) and in total motile sperm count (mean percent change 370 +/- 216, p = .03). Percent change in total sperm counts and in total motile sperm counts correlated positively with pretreatment prolactin levels (r = .64, p = .007, n = 16, and r = .62, p = .01, n = 15), but not with the levels of other hormones. The results suggest that in patients with idiopathic oligozoospermia (1) clomiphene citrate therapy may be more effective in the subgroup of patients who have relatively higher prolactin levels, (2) basal and stimulated gonadotropin levels may not be helpful in predicting the response to clomiphene citrate therapy, and (3) lower sperm motility is associated with relatively higher free T4 and lower LH levels. The underlying mechanisms and the clinical utility of the current observations deserve further study.

Adult↗
PubMedDate not supplied

Radioiodine uptake in the head and neck.

OBJECTIVE: To report two cases of sinusitis-associated radioiodine uptake in patients with thyroid cancer and to review the reported causes of false-positive radioiodine uptake in the head and neck area. METHODS: We present the radiologic findings in two patients who had undergone treatment for papillary thyroid cancer and discuss other settings in which radioiodine uptake suggested the presence of metastatic disease. RESULTS: Radioiodine whole-body scans of two patients who had had thyroid cancer demonstrated uptake in the sphenoid and maxillary sinuses, respectively, mimicking bone or brain metastatic involvement. The thyroglobulin levels were low. Computed tomographic (CT) scanning disclosed mucosal swelling in the sinuses, consistent with sinusitis. The radioiodine uptake cleared on a follow-up scan in one case and was more localized than the CT findings in the other. Eighteen causes of false-positive radioiodine uptake in the head and neck area have been reported. On the basis of the mechanism of uptake, they can be classified into four categories: (1) physiologic uptake (ectopic thyroid tissue), (2) nonthyroidal pathologic conditions (dacryocystitis, sinusitis, sinus mucocele, sialadenitis, folliculitis, Warthin's tumor, parotid cyst, porencephaly, posttraumatic cerebromalacia, and inflammation due to dental disease or a nose ring), (3) internal retention (ectasia of the carotid artery and an artificial eye), and (4) external contamination by body secretions (sweat and nasal, tracheobronchial, lacrimal, and salivary secretions). The estimated prevalence of external contamination in the head and neck area on whole-body radioiodine scans is 0.3%. CONCLUSION: Physicians should rule out the presence of radioiodine uptake by inflamed mucosa of the paranasal sinuses, as well as various other causes of false-positive radioiodine uptake, before metastatic thyroid cancer in the head and neck area is diagnosed.

Carcinoma, Papillary↗