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N Karkavitsas

Publications and source records attributed to N Karkavitsas.

At least 19 recordsLinked to original sources
PubMed2006

Increased human placental growth hormone at midtrimester pregnancies may be an index of intrauterine growth retardation related to preeclampsia.

OBJECTIVE: To evaluate the relationship between maternal serum and amniotic fluid levels of human Placental Growth Hormone (hPGH) with the fetal intrauterine growth retardation (IUGR) related to preeclampsia. DESIGN: We analyzed samples in pairs of serum and amniotic fluid retrospectively from 25 women, who manifested preeclampsia and IUGR in the late second or the third trimester of gestation. The samples were obtained at 16-22 weeks' gestation during amniocentesis for fetal karyotyping. At this time, there was no clinical or sonographic evidence of preeclampsia or IUGR, respectively. Sixty-two serum samples were used as controls which were obtained at 16-22 weeks' gestation from women with singleton, uncomplicated pregnancies, with normal outcome, and appropriate for gestational age neonatal birth weight. Forty-seven amniotic fluid samples were also used as controls which were obtained at 16-22 weeks' gestation from the women that were included in the control group who underwent an amniocentesis. hPGH levels were measured by a solid phase immunoradiometric assay. RESULTS: The mean hPGH values in the serum and the amniotic fluid of the IUGR related to preeclampsia affected pregnancies were significantly higher (P<0.05) than those of the normal pregnancies at 16-22 weeks' gestation: mean+/-SD in the serum was 13.16+/-10.52 ng/ml vs. 4.39+/-2.23 ng/ml; mean+/-SD in the amniotic fluid 2.49+/-1.6 ng/ml vs. 0.82+/-0.67 ng/ml. CONCLUSION: hPGH levels in maternal serum and amniotic fluid were found to be higher at 16-22 weeks' gestation in pregnancies that will be complicated subsequently by IUGR related to preeclampsia. Our findings suggest that the evaluation of the changes of hPGH levels at midtrimester should be further investigated for the possibility to provide a potential predictive index of IUGR and preeclampsia.

Amniocentesis↗
PubMed2006

Clearance of technetium-99m-DTPA in pulmonary sarcoidosis.

BACKGROUND: The aim of this study was to explore the possible association of the lung clearance of 99mTc-DTPA scan with HRCT lung abnormalities and with the pulmonary function tests [PFTs] in patients with sarcoidosis. METHODS: We studied prospectively 15 patients [5 males, 10 females] of median age 46yr [range 27-67] with histologically proved sarcoidosis. HRCT scoring included the sum of the severity and extent of lymph node enlargement and parenchymal involvement. RESULTS: The mean DTPA clearance half-time [tau 1/ <40 min] was found [mean [SD]] 38.3+/-4.5min. The lymph node enlargement was found 34% and the parenchymal involvement 12%. DTPA clearance was negatively correlated with the parenchymal involvement [r= -0.651, p=0.0091]. The HRCT parenchymal abnormalities were found significantly correlated with PFTs [FVC [r= -0.65, p=0.008] and TLCO [r= -0.76, p=0.02]. CONCLUSIONS: Our data suggest a moderate association between 99mTc-DTPA scan and HRCT in pulmonary sarcoidosis. However, further studies in large scale of sarcoid patients are needed to clarify the role of this novel methodology in the evaluation and follow-up of this disorder.

Adult↗
PubMed2003

Urinary N-telopeptide levels in multiple myeloma patients, correlation with Tc-99m-sestaMIBI scintigraphy and other biochemical markers of disease activity.

Urinary cross-linked N-telopeptide of type I collagen (NTx) has been reported to be a sensitive and specific marker of bone resorption in multiple myeloma (MM). In this study, we measured the levels of NTx in 30 newly diagnosed MM patients and 25 controls. We examined its association with the overall score of skeletal involvement measured by Tc-99m-MIBI scintigraphy and other biochemical markers of bone disease (tumour necrosis factor a (TNF-a), serum calcium and creatinine). We further studied the correlation of NTx with the stage of disease (according to Durie-Salmon criteria) and bone marrow infiltration by plasma cells. High levels of NTx, bone marrow infiltration, TNF-alpha, calcium and creatinine were noted at advanced stages of disease (p < 0.05). NTx and TNF-a were found at significantly higher concentrations in patients with a high overall score (3 and 4) in Tc-99m-sestaMIBI in comparison to a low score (0, 1 and 2; p < 0.05). Positive correlations were found between NTx and TNF-a, as well as between bone infiltration and TNF-a or calcium. In conclusion, NTx is a useful marker for the monitoring of bone resorption in MM and correlates with imaging findings on Tc-99m-sestaMIBI and other biochemical markers of disease activity.

Adult↗
PubMed2003

Contribution of 99mTc-anti-carcinoembryonic antigen antibody and 99mTc-sestamibi scintimammography in the evaluation of high risk palpable breast lesions.

Mammography is the screening test of choice for breast cancer. Its low specificity leads to a large number of unnecessary biopsies. Scintimammography, with either Tc-sestamibi (MIBI) or Tc-anti-carcinoembryonic antigen (CEA) Fab', has been proposed as a non-invasive test to lower the high false positive rate of mammography in certain patients. The two agents have not been compared, nor has their combined application been evaluated. We performed a prospective, non-randomized, open-label, single-centre study of 32 women with clinically and mammographically suspected breast cancer [Breast Imaging Reporting and Data System (BI-RADS, American College of Radiology) 4 or 5]. All patients underwent Tc-MIBI and Tc-anti-CEA Fab' scintimammography, and the results were correlated with histopathology. Overall, the accuracies for MIBI and CEA scans were 90.3% (28/31) and 77.4% (24/31), respectively. The probability of disease after mammography was 0.939+/-0.081 (95% confidence interval, CI). The post-mammography probabilities after positive MIBI or CEA scan were 0.965 and 0.960, respectively, and after negative MIBI or CEA scan 0.750 and 0.875, respectively. None of the above differences is significant. The post-test probability when both scans were positive (irrespective of which was performed first) was 0.977. It can be concluded that there are indications that scintimammography with Tc-MIBI is superior to that with Tc-anti-CEA Fab' when these tests are used as screening tests for breast cancer. However, mammography remains the screening test of choice for highly suspicious clinically palpable breast lesions. In this group of patients, the application of scintimammography with either Tc-MIBI or Tc-anti-CEA Fab' (alone or in combination) offers no additional advantage.

Adult↗
PubMed2002

Octreotide enhances the accelerating effect of erythromycin on gastric emptying in healthy subjects.

BACKGROUND: Erythromycin exhibits gastrokinetic properties through cholinergic pathways. Reports regarding the action of octreotide on gastric emptying are conflicting. AIM: : To assess: (i) the hypothesis that serotonin receptors are involved in the accelerating effect of erythromycin on gastric emptying; and (ii) any modification of the gastrokinetic action of erythromycin induced by octreotide. SUBJECTS AND METHODS: Gastric emptying of a standard meal was estimated in 20 healthy subjects by scintigraphy on three different occasions in a double-blind, placebo-controlled manner and in random order: (i) after placebo; (ii) after 200 mg of intravenous erythromycin; and (iii) after 200 mg of intravenous erythromycin following pre-treatment with either 4 mg of intravenous ondansetron (10 subjects) or 50 micro g octreotide. RESULTS: Erythromycin significantly accelerated gastric emptying in all subjects by abolishing the lag phase. Pre-treatment with ondansetron abolished the accelerating effect of erythromycin by restoring the emptying times to placebo levels. Octreotide significantly enhanced the accelerating effect of erythromycin by reducing both the lag and post-lag phases of gastric emptying. CONCLUSIONS: Serotonin receptors are involved in the accelerating effect of erythromycin on gastric emptying. This effect seems to be enhanced by pre-treatment with octreotide, possibly as a result of the modification of the gastrointestinal hormonal environment.

Adult↗
PubMed2002

Correlation between the uptake of Tc-99m-sestaMIBI and prognostic factors in patients with multiple myeloma.

Technetium 99m-2-methoxyisobutil-isonitrile (Tc-99m-MIBI), also called sestaMIBI, has been used successfully to detect malignant tumours at diagnosis. Recently, it has been proposed as a safe and effective tracer in patients with multiple myeloma (MM). The purpose of this study was to demonstrate the value of the Tc-99m-MIBI uptake in disease detection and to assess the correlation between the uptake of this scintigraphy agent and prognostic factors in newly diagnosed MM patients. Thirty-five untreated patients were enrolled in the study. Tc-99m-MIBI scanning was performed in 33 patients after intravenous injection of 7.4 MBq/kg. Whole-body anterior and posterior scans were obtained after 30 min, 60 min, 2 and 4 h. The correlation between known prognostic factors of MM and the intensity of Tc-99m-MIBI uptake was assessed. Our results showed seven patients with an intensity score of I0, 12 patients with I1, eight patients with I2 and six patients with a score of I3. There was a positive correlation between Tc-99m-MIBI intensity and C-reactive protein (CRP; r=0.506, P < 0.01), erythrocyte sedimentation rate (ESR; r=0.368, P < 0.05), beta2- microglobulin (beta2M; r=0.749, P < 0.001), interleukin-6 (IL-6; r=0.823, P < 0.001), soluble Interleukin-6 receptor (sIL-6r; r=0.806, P < 0.001), serum calcium (r=0.578, P < 0.001) and bone alkaline phosphatase (BAP; r=0.472, P < 0.01). An inverse correlation was found between Tc-99m-MIBI intensity and osteocalcin (OC) and type I procollagen carboxyterminal propeptide (PICP). In conclusion, the results of this study suggest that more extensive disease activity, as determined by high levels of CRP, beta2M, IL-6 and sIL-6r correlated with a higher uptake of the radiotracer.

Adult↗
PubMed2002

Association between increased levels of IL-2 and IL-15 and outcome in patients with early acute respiratory distress syndrome.

BACKGROUND: Acute respiratory distress syndrome remains a serious, often fatal, condition, despite progress in modern critical care treatment. Cytokines play an important role in the pathogenesis of the syndrome, although their role in the evolution and outcome has not been clearly elucidated. We explored whether the measurement of serum and bronchoalveolar lavage IL-2 and IL-15 at the time of hospital admission can predict the outcome of this syndrome. METHODS: Serum and bronchoalveolar lavage levels of IL-2 and IL-15 were measured in eight patients with ARDS (group A) and 26 patients on high risk for ARDS development who never developed ARDS (group B) from samples obtained at the time of admission. RESULTS: Serum IL-2 (P > 0.05) and IL-15 (P < 0.05) levels were higher in group A than in group B. Serum levels of both cytokines were higher in patients who did not survive in both of the groups A and B compared to those who survived (P < 0.05, and P < 0.0001, respectively). The only significant change in BALF was the higher level of IL-15 in surviving group A patients (P < 0.05) when compared with the non survivors of the same group. For a serum cut-off level of 173 pg mL(-1) for IL-2 and 250 pg mL(-1) for IL-15, they exhibited a very high positive predictive value (PPV), negative predictive value (NPV), sensitivity and specificity for survival (100% in all). A positive correlation was found between serum levels of both cytokines and APACHE II score (IL-2, r = 0.61, and IL-15, r = 0.62, respectively, and P < 0.0001 for both). CONCLUSION: Determination of serum IL-2 and IL-15 levels may be a valuable and simple aid to improve identification of patients with ARDS or at risk for ARDS who are at high risk of subsequent mortality.

APACHE↗
PubMed2001

Value of Tc-99m sestamibi scintigraphy in the detection of bone lesions in multiple myeloma: comparison with Tc-99m methylene diphosphonate.

Technetium 99m-2-methoxyisobutylisonitrile (Tc-99m MIBI) is a lipophilic agent that accumulates preferentially within living malignant cells due to the higher transmembrane electrical potential as a consequence of the higher metabolic rate than in the surrounding normal cells. It has been effectively used to detect malignant tumors at diagnosis and follow-up and has been reported to be useful in detecting disease lesions in multiple myeloma. We studied 28 consecutive patients with multiple myeloma at diagnosis to determine the value of Tc-99m MIBI in comparison with Tc-99m methylene diphosphonate (MDP), conventional X-rays, computed tomography (CT) scan, and magnetic resonance imaging (MRI). We found 26 patients with obvious osteolytic lesions in X-rays, 22 patients with positive Tc-99m MIBI scans, and 15 patients with positive Tc-99m MDP scans. There was no coincidence of the positive lesions in the two scans, while in two patients the osteolytic areas were positive in the Tc-99m MDP scans, and in one case the osteolytic area was positive in the Tc-99m MIBI scan. The intensity of Tc-99m MIBI scans correlated with disease activity as determined by lactate dehydrogenase (LDH) (p<0.05), C-reactive protein (CRP) (p<0.01), beta2-microglobulin (p<0.05), and serum ferritin (p<0.01). We believe that Tc-99m MIBI scintigraphy can detect bone marrow lesions in myeloma patients that cannot be detected by other imaging methods and that it can be useful especially in solitary myeloma to exclude other involved sites. In addition, it could be a prognostic factor related to disease activity and multidrug resistance. We believe that a multicenter study is needed to evaluate the usefulness of this agent.

Adult↗
PubMed2001

The role of 99m Tc-sestamibi scintimammography and colour Doppler ultrasonography in the evaluation of breast lesions.

In the present study we evaluated comparatively the diagnostic value of mammography, of 99mTc-sestamibi scintimammography (sestamibi-SC) and of colour Doppler ultrasonography (CD-US) in 116 breast lesions. Diagnosis was based on histopathological examination. Overall, out of 86 malignant tumours, 80 (93%) and 75 (87%) had a positive sestamibi-SC and positive CD-US, respectively. Out of 30 benign lesions, 25 (83%) and 26 (87%) had a negative sestamibi-SC and negative CD-US respectively. The true positive results were similar in palpable and in non-palpable lesions for both methods. Out of 19 non-palpable malignant tumours, mammography confirmed malignancy in only one case (5%), which was significantly lower than the results obtained by sestamibi-SC (89%; Px0.0001) and by CD-US (74%; P=0.0001). In palpable malignant tumours, by using mamography, true positive results were obtained in 54/67 (80.5%) patients, which was significantly lower than the results obtained by sestamibi-SC (94%; P=0.03) and marginally different to the results obtained by CD-US (91%; P=0.13). It is concluded that sestamibi-SC and CD-US are useful tools in clarifying the nature of breast lesions in cases with doubtful mammography. The clinical value of these diagnostic procedures in guiding subsequent therapeutic interventions requires further investigation.

Adult↗
PubMed2000

High intratumoural accumulation of stealth liposomal doxorubicin (Caelyx) in glioblastomas and in metastatic brain tumours.

The blood-brain barrier is a major obstacle for the chemotherapeutic drugs to effectively reach primary or secondary brain tumours. Stealth liposomal drugs are highly accumulated in tumoural tissues. In the present study we investigated the relative accumulation of(99m)Tc-DTPA radiolabelled stealth liposomal doxorubicin (Caelyx) in 10 patients with metastatic brain tumours and five patients with brain glioblastoma undergoing radiotherapy. Patients with metastatic brain lesions were treated with 10 consecutive fractions of radiotherapy (whole brain, 3 Gy/fraction, day 1-12) followed by a booster dose of 9 Gy (3 Gy/fraction, day 21-23). Caelyx, at a dose of 25 mg mg(-2)was given on day 1 and on day 21. Radiolabelled Caelyx accumulation was 13-19 times higher in the glioblastomas and 7-13 times higher in the metastatic lesions, as compared to the normal brain. The drug accumulation in the tumoural areas was 40-60% of the accumulation in the bone marrow of the skull bones. The normal brain radioactivity was <4% of the bone marrow, confirming an important shielding effect of the blood-brain barrier in the normal but not in the tumoural tissue. Four of 10 patients with metastatic lesions showed a complete response in CT-scan performed 2 months following therapy. There was no severe toxicity related to radiotherapy or to chemotherapy noted. It is concluded that stealth liposomal drugs selectively overcome the blood-brain barrier in the tumoural areas. The clinical importance of this observation is now under investigation.

Adult↗
PubMed1999

Liposomal doxorubicin and conventionally fractionated radiotherapy in the treatment of locally advanced non-small-cell lung cancer and head and neck cancer.

PURPOSE: Stealth (ALZA Corporation, Palo Alto, CA) liposomal drug formulation allows a higher intratumoral accumulation and a prolonged plasma half-life of the encapsulated drugs. In the study presented here, we evaluated the feasibility of Stealth liposomal doxorubicin (Caelyx; ALZA Corporation) administered concurrently with conventionally fractionated radiotherapy in the treatment of non-small-cell lung cancer (NSCLC) and head and neck cancer (HNC). PATIENTS AND METHODS: Fifteen patients with NSCLC and 15 with squamous-cell HNC were recruited in two phase I dose-escalation trials. The starting dose of Caelyx was 10 mg/m(2) every 2 weeks (for three cycles during radiotherapy) and was increased by 5 mg/m(2) dose increments for every three patients. RESULTS: The maximum tolerated dose of Caelyx was 20 mg/m(2) for HNC and 25 mg/m(2) in NSCLC patients. Oral/pharyngeal mucositis was the dose-limiting toxicity for HNC patients. "In field" radiation skin toxicity was slightly increased. Hematologic toxicity was minimal. Single photon emission computed tomographic evaluation of Caelyx distribution, using technetium-99m-diethylenetriamine pentaacetic acid labeling, revealed a high intratumoral accumulation of the drug. The tumor to thoracic vessel area count ratio in the NSCLC cases ranged from 0.6 to 1.6 (mean +/- SD, 1.01 +/- 0.29), whereas this ratio was higher (0.8 to 1.85; mean +/- SD, 1.35 +/- 0.39) in HNC cases (P =.049). The complete response rate was 21% in the NSCLC cases and 75% in the HNC cases. NSCLC cases with higher Caelyx tumor accumulation responded better to the regimen. The tumor microvessel density assessed with the anti-CD31 monoclonal antibody directly correlated with the degree of the Caelyx accumulation (P =.007; r =. 92). CONCLUSION: We conclude that combination of radiotherapy with Stealth liposomal doxorubicin is feasible. The potential role of such a regimen in the treatment of highly angiogenic tumors requires further investigation.

Adult↗
PubMed1998

Enhancement of gastric emptying of solids by erythromycin in patients with Roux-en-Y gastrojejunostomy.

BACKGROUND: Roux-en-Y reconstruction is sometimes associated with symptoms that suggest food stasis, as a result of dysmotility of either the gastric remnant and/or the efferent jejunal limb. OBJECTIVE: To study the possible effect of intravenous erythromycin lactobionate on gastric emptying of solids in patients who have undergone a Roux-en-Y procedure. PATIENTS: Twenty-four patients with a Roux-en-Y procedure participated in the study. Ten of them had undergone truncal vagotomy with pyloroplasty; the remaining 14 had undergone a Billroth II subtotal gastrectomy as the initial antiulcer procedure. Sixteen healthy subjects served as controls. METHODS: All healthy subjects and patients underwent assessment of gastric emptying of a standard radiolabeled solid meal after administration of placebo or 200 mg of erythromycin lactobionate intravenously. Scanning was done with a gamma camera, and emptying curves were constructed. From these curves the half-time of gastric emptying was calculated. RESULTS: Patients with severe symptoms of gastric stasis had a significantly longer half-time than did patients with mild or no symptoms (P=.002). Patients with a Billroth II subtotal gastrectomy as the initial antiulcer procedure had a significantly worse grade of symptoms (P=.01) and a significantly prolonged half-time (P=.02) compared with patients with a truncal vagotomy with pyloroplasty as the initial antiulcer procedure. Erythromycin significantly reduced the half-time in the controls (P<.001) and all patients after Roux-en-Y procedure (P<.001). CONCLUSION: Erythromycin could be a useful prokinetic drug in patients with Roux stasis syndrome.

Adult↗
PubMed1998

Tc-99m tetrofosmin myocardial perfusion imaging before and six months after percutaneous transluminal coronary angioplasty.

The role of Tc-99m tetrofosmin single-photon emission tomography (SPECT) in the evaluation of myocardial perfusion before and 6 months after successful percutaneous transluminal coronary angioplasty (PTCA) was assessed in 41 consecutive patients (32 men and 9 women). Twenty-five patients had one-vessel disease, 14 had two-vessel disease, and 2 had three-vessel disease. Thirty-six patients had dilation of one vessel and five patients dilation of two stenosed vessels, with a total of 46 dilated vessels. All patients underwent coronary angiography both before PTCA and 6 months after revascularization. Restenosis was angiographically demonstrated in 16 (39%) patients and 16 (34.8%) vessels. Tc-99m tetrofosmin myocardial SPECT was 81.3% sensitive and 88% specific for the detection of restenosis in the group of patients with a positive predictive value of 81.3% and a negative predictive value of 88%. Sensitivity, specificity, positive predictive value, and negative predictive value were 81.3%, 90%, 76.5%, and 89.7%, respectively, for restenosis detection in specific vessels. It was concluded that most patients who underwent successful PTCA (34 of 41, or 82.9%) had significant (P < 0.001) improvement in their scan image 6 months after the angioplasty, and that Tc-99m tetrofosmin myocardial SPECT is an excellent tool to follow these patients because it can detect restenosis accurately and noninvasively.

Adult↗
PubMed1998

Elevated serum TNF-alpha concentrations are predictive of shortened survival in patients with high-risk myelodysplastic syndromes.

The levels of IL-1 alpha, IL-2, IL-6 and TNF-alpha were measured immunoradiometrically in the sera of 82 myelodysplastic (MDS) patients at diagnosis in an attempt to identify possible relationships between serum cytokine levels and clinical and laboratory parameters of the patients. We found that serum IL-6 and TNF-alpha concentrations were significantly higher in the group of MDS patients than in the normal controls (p < 0.03 and p < 0.001, respectively), while serum IL-1 alpha and IL-2 levels did not differ statistically between patients and control subjects. Elevated serum IL-6 and TNF-alpha concentrations were mainly seen in patients with high-risk myelodysplasia (MDS), i.e. patients with chronic myelomonocytic leukemia (CMML) (p < 0.05 and p < 0.001, respectively), refractor anemia with excess of blasts (RAEB) (p < 0.01 and p < 0.001, respectively), or refrochopy anemia with excess of blasts in transformation to acute leukemia (RAEB-t) (p < 0.001 and p < 0.001, respectively). Patients with low-risk disease, i.e. patients with refractory anemia (RA) or refractory anemia with ringed sideroblasts (RARS), had serum cytokine levels comparable to those of controls. Patients' serum IL-6 and TNF-alpha correlated inversely with the hemoglobin concentration (p < 0.01 and p < 0.05, respectively) and positively with the absolute number of circulating myeloblasts (p < 0.01 and p < 0.001, respectively) and the proportion of bone marrow (p < 0.001 and p < 0.001, respectively) myeloblasts. A negative correlation was also noted between serum TNF-alpha concentrations and patients' survival in high-risk MDS (p < 0.02). We concluded that elevated serum IL-6 and TNF-alpha values are seen mainly in patients with high-risk disease, and that high serum TNF-alpha concentrations are predictive of shortened survival in this group of patients.

Aged↗
PubMed1998

Effect of dual and triple energy window scatter correction methods on image quality in liver scintigraphy.

AIM: To investigate the effect of two scatter correction methods on lesion detectability for both planar and tomographic hepatic imaging. METHODS: All planar and tomographic acquisitions involved simultaneous collection of photons in the main photopeak window (126-154 keV) and three additional windows (92-116, 116-126 and 154-164 keV). Uncorrected and corrected for scatter images were obtained from the same acquisition data. The dual energy window (DEW) and the triple energy window (TEW) scatter compensation methods were used to obtain two sets of corrected images. The DEW method was implemented with main photopeak window 126-154 keV, Compton scatter window 92-126 keV and scatter multiplier k = 0.5. A modified TEW method was also applied with main photopeak window 126-154 keV and scatter subwindows 116-126 keV and 154-164 keV. Phantoms were used to study the effect of scatter correction on contrast and signal-to-noise ratio. The observer's ability to identify lesions was studied on uncorrected and corrected for scatter patient images. RESULTS: In planar imaging, both scatter compensation methods yielded contrast enhancement. However signal to noise ratio (SNR) was degraded to 0.63 and 0.67 when DEW and TEW were applied respectively. In SPECT images, contrast was increased by a factor of 2.4 and 1.7, while SNR was degraded to 0.60 and 0.64 when DEW and TEW methods were used respectively. CONCLUSIONS: Scatter correction using DEW and TEW methods may improve observer's ability to distinguish lesions in planar (p < 0.05 for both methods) and SPECT (p < 0.05 for both methods) liver studies.

Adult↗