EndoNUclease Heteroduplex Cleavage typing (ENUHCT) : une technique universelle de typage avec concept de preuve sur la détection des variants de spike du SARS-CoV-2

Introduction

Le rôle épidémiologique et clinique des variants SARS-CoV-2 a démontré la nécessité de techniques d’identification rapide à partir des prélèvements cliniques. Nous avons développé une technique de typage par clivage endonucléasique des hétéroduplexes (ENUHCT). Elle repose sur le mélange de deux produits PCR (une référence et un échantillon à étudier). Après dénaturation et réhybridation, on obtient des homoduplex (Ref/Ref, Var/Var) et potentiellement des hétéroduplex (Ref/Var). La nucléase clive les heteroduplex créant des fragments de taille différente selon le nombre et la position des mutations. Par électrophorèse capillaire, il est facile de détecter la présence de mutation(s) selon le nombre et à la taille des fragments.

Matériels et méthodes

La preuve de concept a été réalisée avec des souches virales (https://www.european-virus-archive.com/) cultivées en cellules Vero-E6 dans un laboratoire NSB3. Les extraits d’acides nucléiques correspondant à 500 prélèvements cliniques identifiés par séquençage ont été étudiés après codage aveugle.

Amplification PCR : les primers sens (TTACCAGATGATTTTACAGGC) et reverse (AGACTTTAGGTCCACAAAC) [400 nm] amplifient un fragment de 303 pb sous 25-μL avec 12,5 μL de 2X Reaction Mix, 0,5 μL de Superscript II RT/Platinum Taq Mix et 5 μL d’ARN de culture ou 3 μL d’ARN provenant d’échantillons biologiques (30 min/50 °C–2 min/94 °C, puis 40 fois 15 s/94 °C–20 s/55 °C–20 s/68 °C, puis 2 min/72 °C).

Mismatch detection : les 2 produits de PCR sont mélangés vol/vol. Après dénaturation/hybridation, les réactifs du Kit SURVEYOR (IDT) sont ajoutés suivant le protocole et incubés pendant 1 heure à 42 °C.

Capillary electrophoresis : l’analyse des fragments est faite par électrophorèse capillaire (Caliper GXII) sur puce ADNerkinElmer avec LabChip GX Reviewer.

Sanger sequencing : les produits de PCR ont été séquencés par Genewiz.

Résultats

Les résultats obtenus sont en parfaite correspondance avec les résultats théoriques. En associant une souche européenne avec variant UK on obtient 2 fragments (231/72 pb [mismatch en 501]) ; en associant variant UK et variant SA (180/123 pb [mismatch en 484]) ; en associant souche européenne et variant SA on obtient 4 fragments (180/123/72/51 [mismatch en 484 et 501]). De même, les résultats obtenus avec les prélèvements cliniques nous ont permis d’identifier correctement les variants connus et d’identifier de nouveaux variants. Ces derniers ont été confirmés par séquençage.

Conclusion

ENUHCT :

– est simple, sensible, peu coûteuse ;

– permet de détecter les variants reconnus et de découvrir des variants encore non répertoriés ;

– peut être appliquée à d’autres microorganismes ;

– permet de typer plus de 1000 échantillons par jour.

Molecular investigation of tick-borne pathogens in ixodid ticks infesting domestic animals (cattle and sheep) and small rodents (black rats) of Corsica, France

Although livestock farming (sheep, goats, pigs, and cattle) is an important economic activity in Corsica, a French Mediterranean island, knowledge about the tick fauna and microorganisms carried by them remains scarce. This study aimed to investigate the presence and perform molecular characterization of Anaplasmataceae, Rickettsia spp., and Borrelia burgdorferi sensu lato (sl) in tick species collected in Corsica. Ticks from cattle (Bos taurus), sheep (Ovis aries), and rodents (Rattus rattus) were collected from May to September 2016. DNA was purified from ticks, submitted to quantitative real-time polymerase chain reaction (qPCR) and sequenced for phylogenetic analysis. In total, 660 ticks were collected from 111 animals during the study. The most abundant collected tick species from cattle was Rhipicephalus bursa (n = 495; 84.5%), followed by Hyalomma marginatum (n = 91; 15.5%). Rhipicephalus bursa and Ixodes ricinus were the only tick species collected from sheep and rodents, respectively. Overall, Rickettsia was the most common pathogen group (n = 48; 24%) detected in ticks. Sequence analysis of partial gltA and ompA genes revealed the presence of Ri. aeschlimannii and Candidatus Ri. barbariae. Anaplasmataceae DNA was detected in eight (6%) of the 127 cattle pools and in one (2%) of the 61 R. bursa specimens collected from sheep. Sequence analysis of the rpoB gene revealed the presence of one Anaplasma species, A. marginale. Borrelia burgdorferi sl DNA was detected in one pool of H. marginatum collected from cattle and in two (15%) of the 13 I. ricinus pools collected from nine black rats. To our knowledge, this is the first report of the occurrence and molecular characterization of Candidatus Ri. barbariae, an emerging member of the Rickettsia group causing spotted fever, in Corsica. The detection of B. burgdorferi sl DNA, which was previously believed to be rare in Corsica, confirms the presence of this agent on the island.

Baseline characteristics and clinical symptoms related to respiratory viruses identified among patients presenting with influenza-like illness in primary care

Objectives

We aimed to identify patients' clinical characteristics associated with respiratory viruses identified among patients presenting with influenza-like illness (ILI).

Methods

A sample of patients of all ages presenting with ILI was included by physicians of the French Sentinelles network during two seasons (2015/16 and 2016/17). Nasopharyngeal samples were tested for the presence of influenza virus (IV), respiratory syncytial virus (RSV), human rhinovirus (HRV) and human metapneumovirus (HMPV). Patients' characteristics associated with each of the four virus classes were studied using multivariate logistic regressions.

Results

A total of 5859 individuals were included in the study: 48.0% tested positive for IV, 7.9% for HRV, 7.5% for RSV and 4.1% for HMPV. Cough was associated with IV (OR 2.14, 95% CI 1.81–2.52) RSV (OR 2.52, 95% CI 1.75–3.74) and HMPV detection (OR 2.15, 95% CI 1.40–3.45). Rhinorrhoea was associated mainly with HRV detection (OR 1.75, 95% CI 1.34–2.32). Headache was associated with IV detection (OR 1.75, 95% CI 1.34–2.32), whereas absence of headache was associated with RSV and HMPV detection. Dyspnoea was associated with RSV detection (OR 2.33, 95% CI 1.73–3.12) and absence of dyspnoea with IV detection. Conjunctivitis was associated with IV detection (OR 1.27, 95% CI 1.08–1.50). Some associations were observed only in children: dyspnoea and cough with RSV detection (age <5 years), conjunctivitis with IV detection (age <15 years). Period of onset of symptoms differed among aetiological diagnoses. Seasonal influenza vaccination decreased the risk of IV detection (OR, 0.67, 95% CI 0.51–0.86).

Conclusions

This study allowed the identification of symptoms associated with several viral aetiologies in patients with ILI. A proper knowledge and understanding of these clinical signs may improve the medical management of patients.

Influenza-like illness outbreaks in nursing homes in Corsica, France, 2014-2015: epidemiological and molecular characterization

Background

To study the molecular epidemiology of the influenza outbreaks in nursing homes (NHs) to determine whether multiple influenza strains were involved.

Methods

From September to December 2014, NHs in Corsica were invited to participate in an ongoing daily epidemiological and microbiological surveillance for influenza-like illness (ILI) among residents and health care workers (HCWs).

Results

The study involved 12 NHs. Respiratory illness meeting the ILI case definition was observed among 44 residents from whom 22 specimens were collected. Of the 22 residents with a nasopharyngeal sample, 13 (59 %) were positive for at least one of the 11 pathogens analysed. Among these 13 patients, 11 (92 %) presented a confirmed influenza (A/H3N2) and two had another respiratory virus: one human metapneumovirus and one human coronavirus. Of patients with a confirmed influenza A(H3N2), 10 (91 %) were vaccinated against influenza during the 2014–2015 season. Two influenza outbreaks were reported in two NHs, caused by influenza A(H3N2) strains belonging to cluster 3C.3 and 3C.2a. Although antivirals were available, prophylaxis was not used.

Conclusions

Phylogenetic analysis seems to suggest no multiple introduction into the two NHs reporting the two influenza A(H3N2) outbreaks. A number of factors could have contributed to transmitting influenza in NHs including, the absence of administration of antiviral treatment for prophylaxis of all residents/staff regardless of immunization status because of the poor vaccine match during each outbreak, the intensive contacts with incompletely protected residents and HCWs, and the low adherence of NHs to notification of ILI outbreaks to the health authorities.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-2957-z) contains supplementary material, which is available to authorized users.

Serum leptin and bone metabolism in HIV patients treated with highly active antiretroviral therapy

AIM

The role of leptin in bone metabolism has not yet been fully elucidated and results remain controversial. We investigated whether changes in serum leptin correlated to bone mineral density (BMD) occur in human immunodeficiency virus (HIV) patients on highly active antiretroviral therapy (HAART).

METHODS

The study population was 117 HIV patients (67 men, 50 women) on HAART and 50 healthy controls, all with normal body mass index (BMI). Based on whole body BMD as measured by dual energy x-ray absorptiometry (DEXA), patients were classified as having a low (< -1) T-score (L) or a normal (> -1) T-score (N); DEXA scans were also used to determine total body fat (TFM) and percent fat (F%); radioimmunologic assays were used to measure leptin, osteocalcin (OC), bone alkaline phosphatase (BAP), 1,25 (OH)2 D in serum, and pyridinium cross-links (PYD & DPD) in urine.

RESULTS

Of the 117 HIV patients, 54 (46.1%) were classified as L and 63 (53.9%) as N; BMD in both sexes was lower (P <0.01) among the L patients than among either the N patients or the controls; 25/32 L men and 19/22 women were osteopenic, the remaining were osteoporotic. The mean TFM, F%, OC, BAP and PYD & DPD values were higher and the mean 1,25 (OH)2 D values were lower in the L than in the N patients; leptin was higher among the L men (P <0.002) and the L women (P <0.03) than in the N patients. In both sexes. leptin positively correlated with TFM, F%, BAP and PYD & DPD; however, leptin, TFM and F% correlated negatively with BMD. A negative correlation was found between 1,25 (OH)2 D and PYD & DPD in women. At follow-up assessment of 56 HIV patients continuing HAART, leptin and BAP increased and 1,25 (OH)2 D decreased, but not significantly; BMD significantly decreased in women and PYD & DPD increased in men (P <0.02).

CONCLUSIONS

An inverse relationship was found between leptin and BMD in HIV patients with osteopenia/osteoporosis treated with HAART. While the role of leptin in bone metabolism in a setting of HIV is still unclear, an inhibitory effect of leptin associated with a negative action by HAART may be hypothesized.

Cholesteryl ester transfer protein gene polymorphisms are associated with coronary artery disease in Corsican population (France)

The aim of the present study was to investigate the association between coronary artery disease (CAD) and Cholesterol Ester Transfer Protein (CETP) (gaaa)n polymorphisms of the CETP gene in Central Corsica island (France). The study group was composed by 300 unrelated Corsican patients with angiographically documented CAD and 300 unrelated healthy blood donors. Significant differences were observed in the distribution of CETP (gaaa)n alleles between the groups under study (p=0.03; chi(2): 16.8, df: 8). The occurrence of a long allele (408 bp) was higher in cases (12%) than in control group (2%), showing a 6.75-fold increased risk for CAD in Corsica patients (p=0.0055; OR=6.750; 95% CIs=1.47-31.00). The correlation of this polymorphism with the lipid profile (cholesterol, low density lipoprotein-cholesterol, high density lipoprotein-cholesterol and triglycerides) in the patients group was determined. There was a significant association of the long alleles of CETP (gaaa)n with HDL-C levels. In the patient and in the control groups the LL genotypes had lower HDL-C compared with the SS and SL genotypes (p<0.0001). In summary our results suggest that the genetic variation at the CETP gene may play an important role in determining CAD in Corsican population.

Prevalence of genetic risk factors for coronary artery disease in Corsica island (France)

We have investigated the frequencies of seven markers among 100 unrelated individuals with angiographically documented CAD (Coronary Artery Disease) and among 100 unrelated healthy blood donors in the central region of Corsica island (France). The seven polymorphisms analyzed were chosen from six candidate genes involved in (1) Renin-Angiotensin system: Angiotensin converting enzyme (ACE I/D), (2) Lipid metabolism: Cholesterol Ester Transfer Protein gene (CETP TAQ1B), (3) Platelet aggregation: alpha and beta subunits of the platelet GpIIb/GpIIIa integrin complex (GpIIb HPA3 and GpIIIa Pl(A1/A2)), (4) Coagulation fibrinolysis: Plasminogen Activator Tissue (PLAT TPA25 I/D) and Methylenetetrahydrofolate Reductase (MTHFR C677T and A1298C). The samples were genotyped using the polymerase chain reaction followed by restriction enzyme analysis for the RFLPs. No significant difference in allele frequencies between patient and control groups was observed. The occurrence of the MTHFR T677T genotype and of the T677T/A1298A compound genotype is higher in cases (20%) than in the controls (4%). Odds ratio seems to indicate that individuals with the MTHFR T677T genotype and the T677T/A1298A compound genotype had a 6-fold increased risk for developing CAD (ORs = 6; 95% CIs = 1.96-18.28) suggesting a possible association of MTHFR C677T with the risk of CAD in Corsican population.

Genetic Characterization of the Historical Albanian Ethnic Minority of Calabria (Southern Italy)

Three historical ethnic minorities are present in Calabria: Albanians, Greeks, and Occitans. The Albanian ethnic minority is the more populous, having settled in Calabria between the 15th and 17th centuries, and these populations are now located in the provinces of Cosenza and Catanzaro. In the present study the Albanian population structure is analyzed based on the allele frequencies of six classic genetic markers: ACP, GC, PGM1, AK, ADA, and 6PGD. The results show a significant heterogeneity between the Albanian population in Calabria and the population in Molise. Therefore the cultural and reproductive isolation of the Albanian ethnic minority of Calabria is related to a great genetic peculiarity. Moreover, the frequencies of some alleles, particularly those of the PGM*1W31 variant, and the analysis of the R matrix still show the actual peculiar genetic structure of the Albanians of Calabria, although the genetic flow is evident in the decrease of endogamy and in the increase in the degree of mixing.

β-globin cluster haplotypes in normal individuals and β039-thalassemia carriers from Sardinia, Italy

Seven polymorphic sites in the beta-globin cluster in association with specific thalassemia mutations were analyzed in a sample from Sardinia, Italy. In order to verify previous works carried out on normal samples (beta(A)/beta(A)) and family studies on beta-thalassemia homozygotes individuals, the haplotype frequencies in both normal individuals (beta(A)/beta(A)) and beta(0)39-thalassemia carriers (beta(A)/beta0) were studied. In our work chromosomes carrying beta(0)39 mutation are characterized by a prevalence of haplotype II (- + + - + + +) (52%) relative to haplotype I (+- - - - + +) (29%), in contrast, among chromosomes with beta(A) the frequency of haplotype I is much greater than that of haplotype II. These data confirm what was found by other authors. Nevertheless, our results disagree with those of previous studies of Sardinians, both in frequencies values and in the numbers of haplotypes identified. Population analysis performed with samples carrying the beta-thalassemic mutation highlighted the peculiarity of Sardinians with respect to other Mediterranean populations. The Corsican population is most similar to the Sardinian population, confirming previous analyses performed with both classical markers and mitochondrial and genomic DNA.

Bone mass loss and vitamin D metabolism impairment in HIV patients receiving highly active antiretroviral therapy

AIM

Given the few controversial data about the effect of highly active antiretroviral therapy (HAART) on bone mass in HIV patients, we investigated whether a relationship between osteopenia/osteoporosis risk and HAART exists.

METHODS

In 172 HIV patients, 152 on HAART, 92 including and 60 not including protease inhibitors (PI), 20 naïve and 64 controls, we measured spine/femur bone mineral density (BMD) by DEXA, and assayed serum osteocalcin (O), bone alkaline phosphatase (BAP), 1,25(OH)2 D, parathormone (PTH), calcium (Ca) and urinary pyridinium cross-links (PYD & DPD).

RESULTS

Following WHO BMD t-score criteria, osteopenia was ascertained in >35% of all HAART groups and in 30% of naive. Only HAART patients had osteoporosis, PI patients more frequently, significantly (p<0.03) in spine (21.7% vs 8.3%). Males, intravenous drug users and B-C stage patients have a higher risk for low bone mass. Mean t-score was significantly lower in both spine and femur and O and PYD & DPD higher in PI than non PI patients and controls; 1,25(OH)2 D was significantly lower in all HIV groups than controls, PI patients having the lowest values positively correlating with BMD and negatively with OC and PYD & DPD, and it decreased further in 27 non selected monitored patients continuing on HAART. PTH was higher and Ca lower in HAART patients than controls but not significantly, PTH negatively correlating with BMD.

CONCLUSION

HAART could be associated with osteopenia, even osteoporosis, and it could aggravate the loss in bone mass due to HIV infection itself. We hypothesize that HAART may directly affect bone remodelling and/or may indirectly affect vitamin D metabolism.

The role of (99m)Tc-tetrofosmin pinhole-SPECT in breast cancer non palpable axillary lymph node metastases detection

AIM

We evaluated the usefulness of (99m)Tc-tetrofosmin axillary pinhole (P)-SPECT in breast cancer (BC) non palpable axillary lymph node metastasis detection compared with conventional planar and SPECT scintimammography.

METHODS

We studied prospectively 188 consecutive patients with suspected primary BC, negative at axillary clinical examination. Ten minutes after 740 MBq (99m)Tc-tetrofosmin injection, planar and SPECT scintimammography were acquired, followed by axillary P-SPECT imaging.

RESULTS

At histology, 12 patients had benign mammary lesions and 176 had BC. Axillary lymph node dissection (ALND) was performed in all BC patients, bilaterally in 3 cases: 74/179 axillae had metastases. P-SPECT showed a significantly higher overall sensitivity than SPECT and planar (93.2% vs 85.1% and 36.5%, respectively; p<0.05 and p<0.0005, respectively) and was false negative in 5 patients with 1 metastatic node each, micrometastatic in 4/5 cases; SPECT and planar were also false negative in these 5 cases and in 6 and in 42 further cases, respectively. P-SPECT added important prognostic information by distinguishing single from multiple and pound 3 from >3 nodes; only P-SPECT defined the exact number of nodes in 15/25 patients with 2-4 nodes. P-SPECT showed the highest accuracy and NPV: 92.7% and 95%, respectively (SPECT 90.5% and 90%, respectively; planar 73.2% and 68.9%, respectively).

CONCLUSION

(99m)Tc-tetrofosmin axillary P-SPECT appears highly accurate in BC non palpable axillary lymph node metastasis detection and significantly more sensitive than both planar and SPECT, its few false negative results predominantly concerning micrometastases; moreover, only P-SPECT gave additional important prognostic information. Given its very high NPV, P-SPECT could also be used to better select patients who might avoid ALND.

The usefulness of 99mTc tetrofosmin scintigraphy in patients with breast cancer recurrences

To verify the usefulness of 99mTc tetrofosmin scintigraphy in the follow-up of breast cancer patients, we studied 72 surgically treated breast cancer patients with suspected local recurrences (20 cases) or distant metastases (52 cases) at clinical examination and/or at conventional imaging procedures (CIPs). In all patients, a whole-body scan followed by planar and single photon emission tomography (SPET) images of selected sites were acquired 10 min after the intravenous injection of 740 MBq of 99mTc tetrofosmin, using a rectangular dual-head gamma camera equipped with high-resolution parallel-hole collimators. Loco-regional recurrences were diagnosed in 19 patients and distant metastases in 44 cases, while benign lesions were ascertained in nine cases. 99mTc tetrofosmin SPET showed higher sensitivity, specificity and accuracy per patient than did CIP (96.8% vs 85%, 77.7% vs 55.5% and 94.4% vs 81.1%, respectively) with statistical significance for accuracy (P <0.05). The combined use of SPET and CIP achieved 100% sensitivity and 98.6% accuracy. Planar imaging did not give additional information in respect of either SPET or CIP, showing significantly lower sensitivity and accuracy values (47.6% and 52.8%, respectively). Our data seem to suggest that 99mTc tetrofosmin SPET, but not planar, may be useful in the follow-up for the detection of loco-regional and distant recurrences in patients with breast cancer. The technique can play a complementary role to conventional diagnostic imaging procedures in selected patients.

Usefulness of ^99mTc-Tetrofosmin Scintigraphy in Different Variants of Kaposi’s Sarcoma

We investigated ^99mTc-tetrofosmin scintigraphy in 27 patients with Kaposi’s sarcoma: 20 had classic (CK), 5 AIDS-associated (AK) and 2 transplantation-associated (TK) variants. Twenty-three patients had clinically evident cutaneous and/or mucosal lesions, 9 of them with associated sarcomatous lymphadenopathy; 2 TK patients had only lymph nodes or other extracutaneous Kaposi sites. Both planar and SPECT ^99mTc-tetrofosmin scintigraphies were performed in all cases and neck pinhole (P)-SPECT in selected patients. ^99mTc-tetrofosmin uptake was observed in 88% of patients with clinically evident cutaneous and/or extracutaneous Kaposi lesions. Scintigraphy gave additional information on cutaneous lesion extent, particularly SPECT regarding deep invasion and subclinical sites in some cases. However, scintigraphy was less sensitive in the detection of small, isolated and scattered lesions. SPECT/P-SPECT were positive in 8/8 patients with sarcomatous lymph nodes, planar imaging in 5/8, ultrasonography in 7/8, while all procedures were negative in 6 other patients with reactive or HIV infection lymph nodes. SPECT demonstrated lymphadenopathy remission in 1 TK patient after immunosuppressive therapy modification and, like planar imaging, ascertained an associated lymphoma with ⁶⁷Ga-citrate combined. ^99mTc-tetrofosmin scintigraphy, especially SPECT, can be useful both in the detection and staging of Kaposi sarcoma lesions as a complementary tool to clinical and other conventional diagnostic methods.

99mTc-Tetrofosmin pinhole-SPECT (P-SPECT) and radioguided sentinel node (SN) biopsy and in breast cancer axillary lymph node staging

We compared 99mTc-Tetrofosmin P-SPECT with radioguided SN biopsy in 101 T1/T2 BC pts to predict axillary lymph node status. The day before surgery all pts underwent lymphoscintigraphy (LS) to mark the SN, following subdermal injection of 99mTc-colloidal sulphur surrounding the breast lesion. LS was combined with pre and intraoperative gamma probe. Previously, all pts had also undergone P-SPECT. ALND was performed in all cases. The SN(s) was detected in 97/101 cases (96%) by LS and gamma probe; in the 4 missed cases P-SPECT predicted lymph node status. In the 97 comparable cases, radioguided SN biopsy showed a slightly higher accuracy than P-SPECT (94.8% vs 93.8%), but a higher false-negative rate (14.3% vs 8.6%); P-SPECT had a higher NPV (95.2% vs 92.5%). The two procedures when combined achieved 100% accuracy. Radioguided SN biopsy alone had 100% accuracy only in pts with BC < 15 mm. P-SPECT had 3 false negative cases, 2 of which were micrometastatic SNs, and 3 false positives. P-SPECT identified 81.2% of cases with a single node, determined the exact number of nodes in 82.6% of cases with 1 to 3 node and correctly classified 93.7% of pts as having < or = 3 or > 3 metastatic nodes. Radioguided SN biopsy seems indicated in selected, early stage, small BC pts, while P-SPECT shows a high sensitivity independent of primary tumor size, giving additional important preoperative prognostic information. The two procedures combined provided a better axillary lymph node status prediction in T1/T2 carcinomas, and could thus improve ALND pt selection.

(99)mTc-tetrofosmin SPET in the detection of both primary breast cancer and axillary lymph node metastasis

The aim of this study was to evaluate the usefulness of (99m)Tc-tetrofosmin single-photon emission tomography (SPET) in the detection of both primary breast cancer and axillary lymph node metastasis. We studied 192 consecutive patients in whom primary breast cancer was suspected on the basis of mammography and/or physical examination. After intravenous injection of 740 MBq (99m)Tc-tetrofosmin, both planar and SPET scintimammography was performed in all patients using a rectangular dual-head gamma camera equipped with low-energy, high-resolution, parallel-hole collimators. In 175 patients with breast cancer at histology, the per-lesion overall sensitivity of SPET and planar imaging for the detection of breast cancer was 95.8% and 75.9% (P<0.0005), respectively. The sensitivity of SPET and planar imaging was, respectively, 96.5% and 79.5% in palpable (P<0.0005) and 90% and 45% in non-palpable lesions (P<0.01). With regard to lesion size, the sensitivity of SPET and planar imaging was, respectively, 90.5% and 45.2% in lesions < or =10 mm ( P<0.0005), 95.3% and 81.4% in lesions of 11-20 mm (P<0.005), 100% and 84.6% in lesions of 21-30 mm (P<0.05) and 100% and 95.8% in lesions >30 mm (P>0.05). In the remaining 17 patients with benign mammary lesions at histology, per-lesion overall specificity of SPET and planar imaging was 76.2% and 85.7% (P>0.05), respectively. Neither SPET nor planar imaging showed false-positive results in non-palpable lesions or in those < or =10 mm. In 173 breast cancer patients submitted to axillary lymph node dissection (ALND), per-axilla overall sensitivity of SPET and planar imaging in the detection of axillary lymph node metastasis was 93% and 52.3% ( P<0.0005), respectively. The sensitivity of SPET and planar imaging was, respectively, 100% and 82.6% in palpable nodes (P>0.05), 90.5% and 41.3% in non-palpable nodes (P<0.0005), 92.8% and 35.7% in the presence of < or =3 nodes ( P<0.0005) and 93.2% and 68.2% in the presence of >3 nodes (P<0.005). The specificity of SPET and planar imaging was 91% and 100% (P<0.05), respectively. (99m)Tc-tetrofosmin SPET appears to be a reliable method for the detection of both primary BC and axillary lymph node metastasis, and its diagnostic accuracy exceeds that of (99m)Tc-tetrofosmin planar scintimammography. The use of SPET is particularly important in the identification of small non-palpable primary carcinomas and metastatic axillae with < or =3 non-palpable lymph nodes. More extensive use of SPET appears warranted in the management of breast cancer patients.

The role of 99mTc-tetrofosmin Pinhole-SPECT in breast cancer axillary lymph node staging

The number of metastatic axillary nodes represents one of the most important prognostic factors in preoperative breast cancer patients. 99mTc-Tetrofosmin high resolution Pinhole (P)-SPECT was employed in 112 patients, 100 with breast cancer and 12 with benign mammary lesions, to ascertain axillary lymph node involvement. Axillary P-SPECT images were acquired utilizing specific software connected to a circular high resolution, single-head gamma camera equipped with a pinhole collimator with aperture size of 4.45 mm, rotating 180 degrees around the involved axilla. At the same time, patients also underwent conventional SPECT and planar acquisitions. Per-patient sensitivity and specificity were 100% and 93.6% for P-SPECT, 96.2% and 93.6% for SPECT and 56.6% and 100% for planar imaging, respectively. Moreover, P-SPECT detected more than 51% of lesions ascertained by histology, whereas SPECT and planar detected 32.6% and 20.3%, respectively. Only P-SPECT succeeded in identifying the exact number of metastatic axillary lesions in patients with multiple nodes; this procedure was able to correctly differentiate 88.67% of patients with 3 or less nodes from those with more than 3, thus giving important prognostic information. These data suggest 99mTc-Tetrofosmin P-SPECT is a reliable imaging method both for staging and prognostic purposes in breast cancer, and its routine use is recommended.

Clinical and laboratory assessment of subclinical thyroid disease

The availability of highly sensitive in vitro tests for the determination of the free fractions of thyroid hormones (FT3 and FT4) and TSH have allowed the identification of latent thyroid disorders (subclinical hyper- and hypothyroidism) where the clinical signs are minor or absent. The TSH determination is the most sensitive in vitro test to define the thyroid function. FT3 is the most suitable for the correct diagnosis of subclinical hyperthyroidism, while FT4 is diagnostic for subclinical hypothyroidism. In patients with acute or chronic non thyroid disease or in case of assumption of drugs which interfere with in vitro diagnostic tests, the interpretation may be difficult.

[Liver resection with the water dissector; preliminary experience of 8 cases]

New methods for the resection of liver parenchyma was developed in order to simplify liver surgery. The object of our study was to test a method using the water dissector, a rather new equipment. Eight patients, four men end four women, have been operated, from March to September 1997, using the water dissector. Age of the patients ranged from 42 to 83 years (mean age 67 years). Indication for surgery was liver metastasis from colon cancer (6 patients), and gallbladder cancer (2 patients). 1 right lobectomy, 1 left side segmentectomy, 2 V and IV segments resection, 1 unitectomy of the VII segment and 2 III and IV segment resections was performed. In the first four patients we used the Pringle manoeuvre (clamping of the liver stalk), while we did not do it in the last four so we could compare both the operation time and the loss of blood with or without this manoeuvre. One patient died of ARDS in the seventh post-operative day, another patient, who underwent a right lobectomy, developed a biliary fistula which healed in the 10 degrees postoperative day. All the seven surviving patients was in good health, with normal liver ultrasonography when checked on the 31/12/1997. Our results show that the water dissector offers the possibility to isolate vascular stalks very easily, both with a posterior ilar approach and with an intraparenchymal approach, making possible a very accurate haemostasis, in such minimizing blood and biliary losses. This method allows the performing of oncologically correct dissections and in the meanwhile the saving of as much healthy parenchyma as possible.

[Preoperative radiotherapy in cancer of the rectum. Our 5-year experience]

Since 1990, 41 patients with rectal carcinoma have been submitted to preoperative radiotherapy, which induced a shrinkage of the tumor, favouring its surgical resection. Besides, in 3 cases the operative specimens were tumor free, and a higher incidence of A and B 1 categories was found. Surgical results have been compared with an analogous group of 20 patients, where surgery was performed as a first procedure, then followed by radiotherapy in 9. No increase of postoperative complications was observed. While analysis of follow-up results demonstrates a decrease of tumour recurrence in patients with preoperative radiotherapy, no difference in survival was registered, because of the development of extra-pelvic metastases.

[Association of cervico-uterine carcinoma and other extra-uterine primary neoplasms. Observations on 31 cases]

Out of 874 patients undergoing radiotherapy for carcinoma of the uterine cervix, 31 cases (3.5%) of second primary malignant tumour in another site were encountered. Half the cases preceded and half followed uterine cancer. The data are analysed and discussed.