The role of lymph node revealing solution on the improvement of lymph node harvest in colorectal cancer specimens.

AIM: The correct analysis of lymph node status is one of the most important parameters for the accurate pathological diagnosis of colorectal cancer. Our aim was to evaluate the number of lymph nodes among the specimens obtained from colorectal resections due to colorectal cancer, before and after the routine use of a lymph node revealing solution (LNRS). METHOD: Data from 780 surgical specimens from patients of both genders with colorectal cancer were studied. The cases were divided chronologically into two groups: the conventional group included 497 specimens treated with conventional methods, i.e. without the use of the LNRS (January 2000 to July 2007), and the LNRS group included 283 specimens examined through the routine use of this solution (August 2007 to July 2012). RESULTS: Most patients were female (57.4%) with a median age of 62 years. The median lymph node number was 18, and 75.9% of the cases (592) had 12 or more nodes dissected. Lymph node metastases were noted in 334 cases (42.8%). A median of 24 lymph nodes was dissected in the LNRS group compared to 15 in the conventional group (P < 0.001). The LNRS group had 9.2% of cases with fewer than 12 lymph nodes dissected compared with 32.6% in the conventional group (P < 0.001). CONCLUSIONS: The use of the LNRS increases the number of lymph nodes obtained from colorectal cancer surgical specimens and can help to reduce the number of cases with < 12 lymph nodes.

A pilot study evaluating 99mTc-anti-TNF-alpha scintigraphy in graves' ophtalmopathy patients with different clinical activity score.

The present study describes the preliminary results of the use of 99mTc-anti-TNF-α scintigraphy as a new diagnostic approach to evaluate patients presenting with Graves' ophthalmopathy (GO). Patients (n=25) presenting at different inflammatory stages of GO and 10 healthy volunteers underwent 99mTc-anti-TNF-α scintigraphy. Images were obtained 15 min after the intravenous injection of 370 MBq (10 mCi) 99mTc-anti-TNF-α. Planar images were obtained in a 256×256 matrix (each lasting 5 min) and single photon emission computed tomography (SPECT) scan lasting 13 min. Regions of interest (ROI) were drawn on the orbit and cerebral hemispheres. The uptake of 99m Tc-anti-TNF-α in these regions was compared and positive scintigraphy established when the ROI was >2.5. In addition, uptake for each positive exam was scored as either slight (2.6-5.1), moderate (5.2-7.6), or high (>7.6). In this pilot study, 69 orbits were evaluated (1 patient had only 1 eye), and 27 had a positive CAS (≥3/7). Scintigraphies were positive in 38 orbits. Comparing the results of the exams with CAS, a high sensitivity and negative predictive values were determined for scintigraphy (96.3% and 96.7%, respectively). However, the specificity and the positive predictive values were 71.4% and 68.4%, respectively, with an accuracy of 81.2%. The exclusion of examinations that were slightly positive from the analysis resulted in an improvement in test accuracy (95.5%). The preliminary results suggest that 99mTc-anti-TNF-α scintigraphy is a promising procedure for the evaluation of active orbital inflammation in GO.

Radioactive synovectomy with (90) yttrium and (153) samarium hydroxyapatite in haemophilic joints: preliminary study on radiation safety.

Most countries still do not achieve 1 IU of factor VIII/capita sufficient for survival. Although primary prophylaxis prevents synovitis, is not universally used. Chronic synovitis is treated with arthroscopy at expense of considerable amount of coagulation factors, and specialized surgeons. Radioactive synovectomy (RS) is a minimally invasive and cost effective alternative to arthroscopy, often considered first the option for persistent synovitis. Even without established causation with cancer, RS is avoided by some, due to this concern. We aim contributing to the understanding of RS safety regarding malignancy, presenting a large number of treated patients, and a single case of cancer. Three centres in Brazil applied RS with (90) Yttrium Citrate, (90) Yttrium hydroxyapatite or (153) Samarium hydroxyapatite in haemophilic joints and performed a survey addressing cancer in these patients. Four hundred and eighty eight patients (ages 3-51) received 1-3 RS (total 842) and follow-up was 6 months to 9 years. One patient aged 14 years presented Ewing sarcoma, 11 months after RS. The tumour was treated successfully with surgery and chemotherapy. Causality of cancer by RS is improbable in this case. Accordingly, latency here is far below minimum 5-10 years for radio-induction of solid tumours. Moreover, ES is not a typically radio-induced tumour, even at high doses. In agreement with others, though recognizing limitations, this study suggests RS is safe regarding cancer induction. Synovitis is a known burden for patients. The decision of making reasonable usage of RS should be outweighed with the risks of leaving synovitis untreated.

Protocatechuic acid alkyl esters: hydrophobicity as a determinant factor for inhibition of NADPH oxidase.

This study presents the increased efficiency of NADPH oxidase inhibition produced by esterification of protocatechuic acid (P0). Alkyl esters bearing chain lengths of 4 (P4), 7 (P7) and 10 (P10) carbons were synthesized and their oxidation potential, hydrophobicity, antiradical activity, inhibition of superoxide anion (O2°(-)), and the abilities to affect hypochlorous acid (HOCl) production by leukocytes and inhibit myeloperoxidase (MPO) chlorinating activity were studied. The increased hydrophobicity (logP, 0.81-4.82) of the esters was not correlated with a significant alteration in their oxidation potential (0.222-0.298 V). However, except for P10, the esters were ~ 2-fold more effective than the acid precursor for the scavenging of DPPH and peroxyl radicals. The esters were strong inhibitors of O2°(-) released by activated neutrophils (PMNs) and peripheral blood mononuclear cells (PBMCs). A correlation was found between the carbon chain length and the relative inhibitory potency. P7, the most active ester, was ~ 10-fold more efficient as NADPH oxidase inhibitor than apocynin. The esters strongly inhibited the release of HOCl by PMNs, which was a consequence of the inhibition of NADPH oxidase activity in these cells. In conclusion, as effective inhibitors of NADPH oxidase, the esters of protocatechuic acid are promising drugs for treatment of chronic inflammatory diseases. Moreover, this is the first demonstration that, besides the redox active moiety, the hydrophobicity can also be a determinant factor for the design of NADPH oxidase inhibitors.

9°Yttrium-hydroxyapatite: a new therapeutic option for radioactive synovectomy in haemophilic synovitis.

Recurrent haemarthroses often lead to chronic synovitis in patients with haemophilia and von Willebrand disease. Radioactive synovectomy with yttrium-90 (9°Y) citrate is frequently used to treat this complication, usually with good results. Since 2006, the Nuclear Energy Research Institute (IPEN, Sao Paulo, Brazil) has produced hydroxyapatite particles labelled with 9°Y for radioactive synovectomy. The aim of this study was to compare the results achieved by both forms of 9°Y in the treatment of haemophilic synovitis. We included 221 joints from 136 patients (age range: 6-20 years), treated by one of the two radiopharmaceuticals, at the Hemocenter of Mato Grosso, Brazil. The outcomes analysed were the annual frequency of haemarthrosis, articular pain and joint range of motion before and 1 year after RS. Similar results were achieved regardless of whether 9°Y hydroxyapatite or 9°Y citrate was used, and results were independent of the joint type, age, gender, radiologic stage and presence of inhibitors. 9°Y hydroxyapatite appears to be equivalent to the reference product 9°Y citrate in the treatment of chronic synovitis associated with bleeding disorders.

Bone marrow cell transplant does not prevent or reverse murine liver cirrhosis.

We tested the effect of bone marrow cell (BMC) transplantation in either preventing or reversing cirrhosis on an experimental model of chronic liver disease. Female Wistar rats were fed a liquid alcohol diet and received intraperitoneal injections of carbon tetrachloride (CCl4) over 15 weeks. Ten animals (cell-treated group) received five injections of BMCs during the cirrhosis induction protocol (on the 4th, 6th, 8th, 10th, and 12th weeks) and four animals received the cells after liver injury was established through tail vein. Nine animals (nontreated group) were submitted to the previously described protocols; however, they received vehicle injections. Analyses were performed to verify whether the infusion of cells was effective in preventing the development of cirrhosis in our model of induction, and if the cells could reverse cirrhosis once it was established. Hepatic architecture and fibrotic septa were analyzed in liver slices stained with hematoxilin & eosin and Sirius red, respectively. Fibrosis quantification was measured by Sirius red histomorphometry. Indirect immunofluorescence was performed to detect the amount of tissue transglutaminase 2. Blood analyses were performed to assess liver injury and function by the assessment of alanine aminotransferase and albumin. Ultrasound was performed to analyze the portal vein caliber and presence of ascitis. Cirrhosis features (regenerative nodules and fibrous septa) were observed in histopathology after 15 weeks of continuous hepatic injury in nontreated and cell-treated groups. Collagen content, immunofluorescence analysis, and biochemical and ultrasound parameters were similar in nontreated and cell-treated groups; however, both groups showed significant differences compared to a normal control group. Cell infusions with bone marrow-derived cells seem to be ineffective in improving morphofunctional parameters of the liver when applied to chronic cases either during or after establishment of the hepatic lesion.

Is surface orientation a determinant for colonisation patterns of vagile and sessile macrobenthos on artificial reefs?

In order to examine how substratum colonisation can affect community structure, a 1-year study was conducted at the Faro/Ancao artificial reef (Algarve, Portugal). In the study of hard substratum communities, motile species are usually neglected and only the conspicuous species are taken into account. Therefore, the development of vagile and sessile components of the epibiotic community were analysed separately. Differences between assemblages on horizontal surfaces, but not on vertical surfaces, were detected. Multivariate analysis detected differences in macrobenthic community structure either considering sessile or motile components. However, significant differences were only detected for vagile fauna. Moreover, this study suggests that for hard substratum communities, analysis of the vagile fauna is important and should be taken into account in the functioning of the artificial raft.

Expression of heterochromatin protein 1 in the primary tumor of breast cancer patients in the presence or absence of occult metastatic cells in the bone marrow.

Gene silencing may occur in breast cancer samples from patients presenting with occult metastatic cells in the bone marrow and one mechanism regulating gene suppression is heterochromatin formation. We have studied whether members of the heterochromatin protein 1 family (HP1Hs alpha, HP1Hs beta and HP1Hs gamma), which take part in chromatin packaging and gene expression regulation, were differentially expressed in tumors from patients with and without occult metastatic cells in their bone marrow. Tumor samples and bone marrow aspirates were obtained from 37 breast cancer patients. Median age was 63 years and 68% of the patients presented with clinical stage I/II disease. Presence of occult metastatic cells in bone marrow was detected through keratin-19 expression by nested RT-PCR in samples from 20 patients (54.1%). The presence of occult metastatic cells in bone marrow was not associated with node involvement, histological grade, estrogen receptor and ERBB2 immunoexpression. Relative gene expression of HP1Hs alpha, HP1Hs beta and HP1Hs gamma was determined by realtime RT-PCR and did not vary according to the presence of occult metastatic cells in bone marrow. In addition, the combined expression of these three transcripts could not be used to classify samples according to the presence of bone marrow micrometastasis. Our work indicates that regulation of heterochromatin formation through HP1 family members may not be the sole mechanism implicated in the metastatic process to the bone marrow.

Monitoring rheumatoid arthritis synovitis with 99mTc-anti-CD3.

The aim of this study was to investigate the feasibility of using a monoclonal antibody (OKT3) labelled with technetium-99m (99mTc) to monitor disease activity in patients with rheumatoid arthritis. We evaluated 38 patients who were diagnosed with rheumatoid arthritis and classified as Classes II and III after functional assessment (according to the revised criteria specified by the American College of Rheumatology). Two sets of planar anterior images of the patients' wrists, metacarpophalangeal and interphalangeal joints, elbows, shoulders and knees joints were obtained 1 h and 3 h after the injection of 99mTc-OKT3. The scintigraphic findings showed significant correlation (p<0.05) between the radiopharmaceutical accumulation of 99mTc-OKT3 and swollen joints, tender joints and the visual analogue scale. They were able to differentiate patients in remission from patients with active synovitis, according to DAS 28. In contrast, there was no correlation between the radiopharmaceutical accumulation and the patients' age, gender, duration of disease or erythrocyte sedimentation rate. A relatively high disease activity score of 28 joints (4.08+/-1.74) was found in the majority of patients. In conclusion, 99mTc-OKT3 scintigraphy is a reliable and objective method for detecting synovial activity, and can be used to observe disease prognosis.

Radioguided occult lesion localization (ROLL) and excision of breast lesions using technetium-99m-macroaggregate albumin and air injection control.

The aim of this study was to assess the efficiency of the radioguided localization and excision technique using radiopharmaceuticals injected directly or close to occult breast lesions. We studied thirty-two consecutive patients with thirty-six occult breast lesions detected mammographically or ultrasonically categorized as BI-RADS 3, 4 or 5. Macroaggregate Albumin (MAA) labeled with (99m)Tc was administered directly or close to the lesion, guided by mammography or ultrasound, followed by an air injection for radiological control. The excision biopsy was carried out with the aid of a hand-held gamma detecting probe and the entire removal of the lesion was verified by X-ray of the surgical specimens or by intraoperatory frozen section examination. Breast cancer was found in 8.3% of BI-RADS 3 lesions, in 33.3% of the BI-RADS 4 lesions and in 66.6% of the BI-RADS 5 lesions. The radiotracer was correctly positioned in 97.2% of the specimens (35/36) allowing the removal of 97.2%. Xray confirmed the entire removal in 27 lesions (75%), intraoperatory frozen section study in 19.4% (7/36) and by both methods in 5.5% (2/36). Radioguided surgery turned out to be an important tool in the removal of non-palpable breast lesions, as a simple, fast and feasible method that can be implemented in the clinical routine of patients with non-palpable breast lesions.

Failure predictors of the sentinel lymph node in patients with breast cancer using Tc-99m sulfur colloid and periareolar injection.

AIM: As sentinel lymph node (SLN) experience rises, it is important to identify factors that can limit lymphoscintigraphic mapping. METHODS: A prospective study was conducted with breast cancer patients that were submitted to sentinel node mapping by lymphoscintigraphy between October 2003 and January 2005. The analyzed factors were: patients' age, body mass index, tumor size, previous breast surgeries, time between a previous biopsy and the radiotracer injection and their impact on preoperative SLN identification. RESULTS: Two hundred and three breast cancer patients were injected with (99m)Technetium-sulfur colloid and submitted to lymphoscintigraphy scan for SLN biopsy. One hundred and eighty-four of these patients (90.64%) had a successfully identified SLN and 19 (9.36%) had a mapping failure. The median age of the successful group was 55.6 years and in the failure group was 57.1 years (P=0.002). The median body mass index was 25.3 and 27.6, respectively (P=0.024). The tumor size did not show any significant difference between the patients with successful mapping and failure (P=0.07). Previous breast surgery was an important limiting factor for SLN mapping (P=0.017). The mean time from biopsy to SLN detection was 23.6 days on the successfully marked patients and 17.4 days in the failure group (P<0.0001). All the 184 successfully mapped patients had the SLN identified. Only one patient of the failure group had the SLN identified using blue dye. CONCLUSION: Advanced age, elevated body mass index, previous breast surgery and a shorter period of time after a breast biopsy are causes for SLN identification failure. The tumor size was not a limiting factor.

Sentinel node identification by scintigraphic methods in cutaneous melanoma.

In melanoma patients lymph node metastasis is an important prognostic factor that indicates the need for therapeutic lymph node dissection. Preoperative lymphoscintigraphy mapping associated with radioguided sentinel lymph node biopsy has become a well established procedure for cutaneous melanoma patients without clinically detectable lymph node metastases (stage I, II). This technique is a versatile way of characterizing the lymphatic basin at risk for metastases and identifying involved lymph nodes. The purpose of the present study was to examine the reproducibility of lymphoscintigraphy and sentinel lymph node biopsy in detecting micro metastases in cutaneous melanoma. The study was a single-institution prospective analysis of 74 melanoma patients, with primary tumors having Breslow thickness > 0.7 mm, who underwent lymphoscintigraphies between May 2002 and September 2003. Technetium-99m sulfur colloid was injected intradermally at the primary tumor site and dynamic images were obtained for 40 minutes. Two observers evaluated the images. One to two weeks after the first lymphoscintigraphy, radioguided lymph node biopsy was performed. For the biopsy, technetium-99m sulfer colloid was injected intradermally in the same manner as performed before. Lymph nodes were identified and removed with the aid of a gamma ray detecting probe (GDP), and were submitted to histopathological analysis. The histopathological analysis of the sentinel lymph nodes collected during surgery was performed in a sequential manner. First, frozen sections were analyzed during surgery. The lymph nodes considered negative by frozen section were analyzed by H&E staining. Subsequently, the slides considered negative with H&E were sent for immunohistochemical analysis. Lymphoscintigraphy identified at least one sentinel lymph node in all patients. Sentinel node biopsy detected metastases in 20 patients (27.2%). In all cases the lymph node basins identified during lymphoscintigraphy were found to have at least one sentinel lymph node during surgery. Frozen section analysis of the lymph node was only able to identify the disease in 35% of the patients eventually found to have micrometastases with H&E and immunohistochemistry. Two lymph nodes were negative with H&E and positive with immunohistochemical analysis. In conclusion, lymphoscintigraphy is a simple procedure that is well tolerated by patients. It is useful in locating sentinel lymph nodes in patients with melanoma and is an important tool in the clinical practice of oncology. We recommend performing H&E, and if necessary, immunohistochemical analysis of all sentinel lymph nodes because of the high rate of false negative results with frozen sections alone.

Identification of sentinel node in breast cancer: comparison between peritumoral and periareolar injection of the radiopharmaceutical contrast medium.

Axillary node status is the most important prognostic factor for patients with primary breast carcinoma. The sentinel node biopsy (SN) technique has received much attention as a possible alternative to axillary lymph node dissection. The aim of this study is to identify the sentinel node by periareolar and subdermal injection of the radiopharmaceutical in four points, independent of tumor topography and the presence of biopsies and/or previous surgery. The peritumoral injection technique was carried out for comparison purposes. This study was performed on 115 patients, divided into 2 groups: Group A (25 patients, peritumoral injection) and Group B (90 patients, injection in four points). All the SN biopsies were studied by both imprint cytology and H&E staining. Control axillary lymph-node dissection was followed in all patients from Group A and in these positive cases from Group B. Twenty-two out of the twenty-five (88%) SNs were identified in Group A. There was no false negative; the sensitivity and specificity were 100%. Eighty-two of the ninety (91.1%) SNs were identified in Group B. Lymphoscintigraphy showed radiopharmaceutical migration to axilla in 93.7% of the cases. Hotspot area was 10 to 100 times the intensity of the background radiation. Among the 92 cases with negative sentinel nodes at intraoperative examination (TP), the SN histopathology confirmed the absence of cancer cells in 89 patients, whereas 3 were positive for metastatic cells. This study shows that periareolar injection in four points seems to be a good lymphatic mapping method for SN identification. We suggest standardizing this site of injection to identify the SNs. More studies to confirm these findings are ongoing.

Diagnosis of renal allograft rejection and acute tubular necrosis by 99mTc-mononuclear leukocyte imaging.

One hundred kidney transplant recipients were evaluated on the first and fifth days after transplantation by Tc-99m mononuclear cell scintigraphy. We have developed a quantitative method to diagnose rejection and acute tubular necrosis (ATN) by comparing regions of interest drawn on allograft scintigraphs at different times after endovenous administration of the labeled cells. We suggest that the use of Tc-99m-WBC may be useful for the early diagnosis of rejection and the differential diagnosis of ATN.

Relationship between endogenous progesterone and follicular dynamics in lactating dairy cows with ovarian follicular cysts.

Two experiments were conducted to examine circulating concentrations of progesterone (P4) in cows with ovarian follicular cysts (OFCs) and to relate differing levels of P4 to subsequent follicular events. In experiment 1, peripheral concentrations of P4 were determined in cows diagnosed with OFCs. Nonpregnant, lactating Holstein and Jersey cows (n = 32) were diagnosed as having OFCs by rectal palpation. Ovarian follicular cysts were then examined by transrectal ultrasonography to confirm the presence of OFCs (follicle diameter, >/=17 mm; absence of luteal tissue). At confirmation, a blood sample was collected for quantification of P4. The concentration of P4 at confirmation was classified as low (<0.1 ng/ml), intermediate (0.1-1.0 ng/ml), or high (1.0-2.0 ng/ml). More OFCs were associated with intermediate (66%) than with either low (28%) or high (6%) concentrations of P4. In experiment 2, the fate of follicles (diameter, >/=10 mm) that formed in the presence of an OFC was determined and related to circulating concentrations of P4 during follicular development. Follicles (n = 59) that formed in the presence of an OFC ovulated (n = 19), formed a cyst (n = 30), or underwent normal growth and regression (NGR; n = 10). Endogenous P4 in the 7-day period during follicular development was classified as low (if P4 dropped to <0.1 ng/ml for 1 day or longer), intermediate (if P4 averaged between 0.1 and 1.0 ng/ml and never dropped to <0.1 ng/ml), or high (if P4 averaged >1.0 ng/ml and never dropped to <0.1 ng/ml). In the presence of intermediate P4, 75% of observed follicles formed cysts, compared with 10% that ovulated and 15% that experienced NGR. In the presence of low P4, 53%, 41%, and 6% of follicles ovulated, formed a follicular cyst, or experienced NGR, respectively. Thus, an association between intermediate P4 and the formation of OFCs was established.

Identification of sentinel node in breast cancer.

Axillary lymphadenectomy is a very important procedure in the staging of breast cancer patients. However, it is associated with a significant morbidity rate. On the other hand, using early diagnosis we can see a high number of cases where the lymph nodes are negatives. With the intention of avoiding unnecessary axillary dissection, the possibility of evaluating a single node has been studied. This lymph node, defined as "sentinel node", would be the first to receive tumoral lymphatic drainage. The aim of this study is to evaluate: (i) the efficacy of the methods to identify the sentinel nodes, (ii) estimate the predictability of the histological examination of the sentinel node in comparison to other nodes of the axilla, (iii) compare the efficacy of the frozen section regarding the definitive histological examination of the same node. This study was performed in 29 patients, and the sentinel node was identified in all of them. It was metastatic in 7 (24.1%). Out of the 22 patients where the node was negative, 15 were submitted to complete dissection. Out of these 15, there was one case (6.7%) where one lymph node of the first level was positive. All 7 patients with the positive sentinel node were submitted to axillary dissection. When comparing the histological examination of the sentinel node with other nodes, we got a sensitivity of 87.5%, specificity of 100%, predictive positive value of 100%, predictive negative value of 93% and efficacy of 95%. The intra-operative examination was made in 24/29 cases (82.7%). The correlation between both examinations was 95.8%. This study shows that the technique of the sentinel node will be a reliable method to avoid radical axillary dissection in breast cancer patients with early diagnosis.

Ovarian follicular cysts in dairy cows: an abnormality in folliculogenesis.

Ovarian follicular cysts are a major reproductive problem in lactating dairy cows. The primary physiological defect leading to the formation of ovarian follicular cysts is a failure of the hypothalamus to trigger the preovulatory surge of luteinizing hormone (LH) in response to estradiol. The factor responsible for this hypothalamic defect may be progesterone. Intermediate levels of progesterone have been shown to prevent ovulation and promote persistence of dominant follicles in normal cycling cows. Recently, we found that 66% of cows with ovarian follicular cysts had progesterone concentrations in an unusual, intermediate range (0.1-1.0 ng/mL) at the time of their detection. A majority of new follicles (76%) that develop in the presence of these intermediate progesterone concentrations became cysts. Only 10% ovulated. Based on these observations, a novel model for the formation and turnover of ovarian follicular cysts is proposed.

Selective activity of butyrylcholinesterase in serum by a chemiluminescent assay.

In a previous study, we showed that purified commercial esterase activity can be detected in a chemiluminescent assay based on the hydrolysis of 2-methyl-1-propenylbenzoate (MPB) to 2-methyl-1-propenol, which is subsequently oxidized by the horseradish peroxidase (HRP)-H(2)O(2) system. The purpose of this study was to verify the applicability of this assay to human serum. The existence of an esterase activity capable of hydrolysing MPB is indicated by the fact that the MPB-serum-HRP-H(2)O(2) system consumes oxygen and emits light. Both signals were abolished by prior serum heat inactivation and were preserved when serum was stored at < or =4 degrees C. Addition of aliesterase inhibitors, such as fluoride ion and trichlorfon or the cholinesterase inhibitor eserine, totally prevents light emission. The butyrylcholinesterase-specific substrate benzoylcholine causes a delay in both O(2) uptake and light emission, while the specific acetylcholinesterase substrate, acetyl-beta-methylcholine, had practically no effect. Purified butyrylcholinesterase, but not acetylcholinesterase, triggered light emission. The finding that butyrylcholinesterase is responsible for the hydrolysis of MPB in serum should serve as the basis for the development of a specific chemiluminescent assay for this enzyme.

Preliminary observation of 99mTc-thymine imaging in breast neoplasms.

New biological knowledge and new diagnostic tools for breast cancer diagnosis may have an important impact on the strategies followed by oncologists in breast cancer management. So far, it has not been possible to label a nucleotide or its precursor with technetium-99m (99mTc) for use in in vivo studies. In this paper, we report the labelling of a precursor, the nitrogenate base thymine, with 99mTc. It has been used to evaluate breast lesions. After animal studies and with the consent of patients, it was employed for evaluation in humans. Thirty-nine women were studied: 32 patients and seven healthy volunteers. Twenty-three malignant lesions showed uptake of labelled thymine. Of the 12 benign cases, there was one false-positive uptake. Labelled thymine was also taken up by one case of malignant microcalcifications. Labelled thymine can be used as a diagnostic method in the identification of malignant anatomo-radiologic palpable lesions of the breast, observed by mammography, possibly avoiding unnecessary biopsies.

Efficacy and tolerability of long-term therapy using high lamivudine doses for the treatment of chronic hepatitis B.

PURPOSE: A long-term follow-up study was carried out to evaluate the tolerability and efficacy of long-term therapy (1 to 3 years) with high doses (150 or 300 mg daily) of lamivudine for chronic hepatitis B. METHODS: Thirty-two patients were studied, including those who were seronegative for hepatitis B e antigen (HBeAg), as well as those with decompensated liver cirrhosis. Viral DNA clearance was monitored by using end-point dilution polymerase chain reaction (PCR), a highly sensitive method. Hepatitis B virus (HBV) polymerase gene mutations associated with resistance were determined by sequencing. RESULTS: Response to lamivudine in the sixth month was observed in 19/32 (59.4%) patients. With one exception, viral DNA results observed at this time were maintained. The YMDD mutation was detected in 12 nonresponder patients (9 YVDD, 2 YIDD, and 1 mixed population Y(V/I)DD), generally associated with the L528M mutation. Re-takeover by the wild type was observed 6 to 18 months after lamivudine withdrawal. Lamivudine response rates in noncirrhotic and cirrhotic patients were 9/18 (50%) and 10/14 (71.4%), respectively. HBeAg to anti-HBe seroconversion was found after different periods in all responder patients. Hepatitis B surface antigen (HBsAg) clearance and anti-HBs seroconversion were occasionally found. CONCLUSIONS: In nonresponder patients, resistant mutants appeared up to the second year of lamivudine therapy. In spite of the presence of resistant mutants, maintenance of therapy was usually associated with a lower viral load. In responder patients, maintenance of therapy was associated with continued absence of detectable HBV DNA in serum, as monitored by highly sensitive methods. No significant side effects caused by lamivudine were observed in our patients, even in those with liver cirrhosis.