Development and validation of a comprehensive model to predict complications after hepatectomy

OBJECTIVE: Despite advances in perioperative care, hepatectomy remains associated with morbidity rates of up to 40%. Currently, available nomograms for predicting severe post-hepatectomy complications do not include early postoperative data. This retrospective observational study aimed to determine whether the parameters routinely measured in patients admitted to the Intensive Care Unit (ICU) after hepatectomy could represent risk factors for severe morbidity and to propose a nomogram scoring system to predict severe postoperative complications. PATIENTS AND METHODS: 411 adult patients who underwent elective hepatectomy at a high-volume tertiary care center for hepatic surgery from December 2016 to June 2022 were enrolled. The primary outcome was the assessment of predictors of 30-day severe postoperative complications following hepatectomy, defined as Clavien-Dindo grade 3a or higher. As a secondary outcome, we aimed to develop an easy-to-use scoring system to estimate the risk of severe postoperative complications. RESULTS: Severe complications occurred in 78 patients (19%). The final model included body mass index, preoperative bilirubin level, and ICU data (i.e., pH, lactate clearance, arterial lactate concentration 12 hours after ICU admission, need for packed red blood cell transfusions, and length of stay). Notably, the latter three variables were proven to be independent predictors of the outcomes. The model showed an overall good fit (C-index=0.754, corrected Dxy=0.692). A calibration plot using bootstrap internal validity resampling confirmed the stability of the model (mean absolute error=0.017, root mean square error of approximation=0.00051). CONCLUSIONS: We developed an accurate and practical scoring system based on preoperative and early postoperative data to predict poor outcomes after hepatectomy. Further external validation on larger series could lead to the integration of such a tool in the routine clinical practice to support patients' management and early warning during ICU stay.

Graphical Abstract

https://www.europeanreview.org/wp/wp-content/uploads/Graphical-Abstract-NEW-2.pdf.

Critical analysis of major and ancillary features of LI-RADS v2018 in the differentiation of small (≤ 2 cm) hepatocellular carcinoma from dysplastic nodules with gadobenate dimeglumine-enhanced magnetic resonance imaging

OBJECTIVE

To evaluate the performance of major features, ancillary features, and categories of Liver Imaging Reporting and Data System (LI-RADS) version 2018 at magnetic resonance (MR) imaging in the differentiation of small hepatocellular carcinoma (HCC) from dysplastic nodules (DNs).

PATIENTS AND METHODS

This retrospective study included cirrhotic patients with pathologically proven untreated HCCs and DNs (≤ 2 cm) and liver MR imaging performed with gadobenate dimeglumine contrast agent within 3 months before pathological analysis, between 2015 and 2018. 37 patients with 43 observations (17 HCCs and 26 DNs) met the inclusion criteria. Two radiologists assessed major and ancillary imaging features for each liver observation and assigned a LI-RADS v2018 category in consensus. Estimates of diagnostic performance of major features, ancillary features, and LI-RADS categories were assessed based on their sensitivity, specificity, positive (PPV), and negative predictive values (NPV).

RESULTS

Major features (nonrim arterial phase hyperenhancement, nonperipheral "washout", and enhancing "capsule") had a sensitivity of 94.1%, 88.2%, and 41.2%, and a specificity of 57.7%, 42.3%, and 88.5% for HCC, respectively. Ancillary features (hepatobiliary phase hypointensity, mild-moderate T2 hyperintensity, restricted diffusion, and fat in the lesion more than adjacent liver) had a sensitivity of 94.1%, 64.7%, 58.8%, and 11.8%, and a specificity of 26.9%, 61.5%, 65.4%, and 76.9% for HCC, respectively. The LR-5 category (determined by using major features only vs. the combination of major and ancillary features) had a sensitivity of 88.2% at both evaluations and a specificity of 76.9% and 80.8% for HCC, respectively. The combination of LR-4, LR-5 categories (determined by using major features only vs. the combination of major and ancillary features) had a sensitivity of 94.1% at both interpretations and a specificity of 65.4% and 26.9% for HCC, respectively. The use of ancillary features modified LI-RADS category in 25.6% of observations (11/43), predominantly upgraded from LR-3 to LR4 (10/11), increasing the proportion of low-grade DNs and high-grade DNs categorized as LR-4 (from 15.4% to 61.5% and from 7.7% to 46.1%, respectively).

CONCLUSIONS

The added value of ancillary features in combination with major features is limited for the non-invasive diagnosis of small HCC; however, their use modifies the final category in a substantial proportion of observations from LR-3 to LR-4, thus allowing possible changes in the management of patients at risk for HCC.

Risk-adjusted benchmarks in laparoscopic liver surgery in a national cohort

Background

This study aimed to assess the best achievable outcomes in laparoscopic liver resection (LLR) after risk adjustment based on surgical technical difficulty using a national registry.

Methods

LLRs registered in the Italian Group of Minimally Invasive Liver Surgery registry from November 2014 to March 2018 were considered. Benchmarks were calculated according to the Achievable Benchmark of Care (ABC™). LLRs at each centre were divided into three clusters (groups I, II and III) based on the Kawaguchi classification. ABCs for overall and major morbidity were calculated in each cluster. Multivariable analysis was used to identify independent risk factors for overall and major morbidity. Significant variables were used in further risk adjustment.

Results

A total of 1752 of 2263 patients fulfilled the inclusion criteria: 1096 (62·6 per cent) in group I, 435 (24·8 per cent) in group II and 221 (12·6 per cent) in group III. The ABCs for overall morbidity (7·8, 14·2 and 26·4 per cent for grades I, II and II respectively) and major morbidity (1·4, 2·2 and 5·7 per cent) increased with the difficulty of LLR. Multivariable analysis showed an increased risk of overall morbidity associated with multiple LLRs (odds ratio (OR) 1·35), simultaneous intestinal resection (OR 3·76) and cirrhosis (OR 1·83), and an increased risk of major morbidity with intestinal resection (OR 4·61). ABCs for overall and major morbidity were 14·4 and 3·2 per cent respectively for multiple LLRs, 30 and 11·1 per cent for intestinal resection, and 14·9 and 4·8 per cent for cirrhosis.

Conclusion

Overall morbidity benchmarks for LLR ranged from 7·8 to 26·4 per cent, and those for major morbidity from 1·4 to 5·7 per cent, depending on complexity. Benchmark values should be adjusted according to multiple LLRs or simultaneous intestinal resection and cirrhosis.

Multicentre evaluation of case volume in minimally invasive hepatectomy

Background

Surgical outcomes may be associated with hospital volume and the influence of volume on minimally invasive liver surgery (MILS) is not known.

Methods

Patients entered into the prospective registry of the Italian Group of MILS from 2014 to 2018 were considered. Only centres with an accrual period of at least 12 months and stable MILS activity during the enrolment period were included. Case volume was defined by the mean number of minimally invasive liver resections performed per month (MILS/month).

Results

A total of 2225 MILS operations were undertaken by 46 centres; nine centres performed more than two MILS/month (1376 patients) and 37 centres carried out two or fewer MILS/month (849 patients). The proportion of resections of anterolateral segments decreased with case volume, whereas that of major hepatectomies increased. Left lateral sectionectomies and resections of anterolateral segments had similar outcome in the two groups. Resections of posterosuperior segments and major hepatectomies had higher overall and severe morbidity rates in centres performing two or fewer MILS/month than in those undertaking a larger number (posterosuperior segments resections: overall morbidity 30·4 versus 18·7 per cent respectively, and severe morbidity 9·9 versus 4·0 per cent; left hepatectomy: 46 versus 22 per cent, and 19 versus 5 per cent; right hepatectomy: 42 versus 34 per cent, and 25 versus 15 per cent).

Conclusion

A volume–outcome association existed for minimally invasive hepatectomy. Complex and major resections may be best managed in high-volume centres.

Effects of Curcumin on Squamous Cell Carcinoma of Tongue: An In Vitro Study

BACKGROUND

The Squamous Cell Carcinoma of the Tongue (TSCC) is the most frequent cancer of oral cavity often characterized by poor prognosis. Conventional therapies are not very efficient and often may cause serious side effects. In this context, introduction of natural substances as possible adjuvant in the treatment and prevention of cancer is becoming a relevant topic. In fact, curcumin has been used for decades in Chinese traditional medicine for its beneficial effects. Curcumin has anticancer properties in many tumors however, its action on the tongue carcinoma is not entirely clear and many other investigations are necessary.

OBJECTIVE

Curcumin seems to be a good adjuvant in the treatment of head and neck tumors. However, these studies are generic and there are not many specific studies on TSCC, the most frequent and most aggressive cancer of the head-neck region. Our goal is to demonstrate its effectiveness also for TSCC.

METHODS

In this study, we evaluated the effects of curcumin on TSCC cells using different concentrations (1, 5, 10, 20 and 50 µM) and 3 different treatment times (24, 48 and 72 hours). The inhibition of adhesion, proliferation, viability, migration and apoptosis was studied.

RESULTS

IC50 value of curcumin is about 10 µM and there have been inhibitory effects even for treatments at low concentrations. Curcumin reduces migration and progression of TSCC cells and it promotes apoptosis and inhibits tumorigenesis.

CONCLUSIONS

These results suggest the possible use of curcumin as an anti-cancer agent in TSCC. However, in vivo studies are needed to confirm these effects and overcome its low bioavailability.

Evaluation of chemical-physical properties and cytocompatibility of TheraCal LC

TheraCal LC (TLC, Bisco Inc., Schaumburg, IL, USA) is a light-cured, resin-modified, calcium silicate-filled base/liner material designed for direct and indirect pulp-capping. In this study the result of the evaluation in vitro of the biocompatibility and chemical-physical properties of TLC are reported. TLC specimens were prepared under aseptic conditions in strict compliance with the manufacturer’s instructions and sterilized. Osteoblast-like cells (MG63) were used. For different time points, solubility, water uptake, alkalinizing activity and cytotoxicity were evaluated. In ddH20 and in DMEM+FBS, TLC showed a loss of material increasing simultaneously with the absorption capacity. The increase of water uptake of the material promoting the solubilization of mineral ions in medium is a requisite for a bioactive material. The alkalinizing activity is correlated to antimicrobial/bacteriostatic activity and to the ability to favor the formation of apatite deposits. The pH values for water absorption after immersion of the disks ranged between 8 and 9 at each times of evaluation. Cytotoxicity was not observed in MG63 cells treated with TLC and after 5 days, the cells were organized to form a confluent monolayer as demonstrated by fluorescence microscopy observation. TLC showed biocompatibility on MG63 cells allowing a physiologic cell growth and differentiation. The chemical-physical properties and biocompatibility of TLC observed in vitro in the present study, allows considering this cement as an innovative pulp-capping material for the vital pulp therapy.

Enhancement patterns of intrahepatic mass-forming cholangiocarcinoma at multiphasic computed tomography and magnetic resonance imaging and correlation with clinicopathologic features

OBJECTIVE

Incidence of intrahepatic mass-forming cholangiocarcinoma (IMCC) is increasing worldwide, especially in patients with chronic liver disease. The small and the histologically well-differentiated IMCCs in chronic liver disease could be arterially hypervascular lesions with/without washout on computed tomography (CT) and magnetic resonance imaging (MRI), mimicking typical hepatocellular carcinoma (HCC). The aim of this work is to evaluate contrast enhancement (CE) patterns of IMCCs at quadri-phasic multidetector CT (4-MDCT) and MRI, using imaging-clinicopathologic correlation.

PATIENTS AND METHODS

The 4-MDCT and MR images of 56 histologically confirmed IMCCs were retrospectively evaluated for tumor morphology and enhancement features. Enhancement pattern was defined according to the behavior of the nodule in arterial (AP), portal venous (PVP) and equilibrium phases (EP), and dynamic pattern was described according to enhancement progression throughout the different phases. Arterial and dynamic enhancement patterns were correlated with chronic liver disease, tumor size and histological differentiation.

RESULTS

Most of the nodules were peripherally hyperenhancing (50%) on AP, and partially hyperenhancing on PVP (67.9%) and EP (80.3%). Forty-six (82.1%) IMCCs showed progressive CE, 7 (12.5%) stable CE and 3 (5.4%) wash-out. In normal liver there were 34 nodules with progressive and 3 with stable CE, whereas in chronic liver disease there were 12 IMCCs with progressive, 4 with stable and 3 with washout pattern (p = 0.01); IMCCs with progressive CE were more differentiated than IMCCs with stable CE and wash-out (p = 0.02).

CONCLUSIONS

The most prevalent enhancement pattern of IMCCs was arterial rim enhancement followed by progressive and concentric filling. The stable and the washout patterns were more frequent in poorly differentiated IMCCs. Contrast washout was observed only in IMCCs emerging in chronic liver disease with a risk of misdiagnosis with HCC.

Cytotoxicity evaluation of five different dual-cured resin cements used for fiber posts cementation

Custom-cast posts and cores are usually used to treat endodontically treated teeth. However, several researches have underlined how these devices may be a much higher elastic modulus than the supporting dentine and the difference in the modulus could lead to stress concentrating in the cement lute, leading to failure. The role of the cement seems to play a fundamental role in order to transfer the strength during the chewing phases. Aim of this research is to record the rate of cytotoxicity of five different dual-cured resin cements used for fiber posts cementation. We tested the cytotoxicity of this five materials on MG63 osteoblast-like cells through two different methods: MTT ([3-4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide succinate) assay which tests for mitochondrial enzyme activity(6) and xCELLigence® system.

Efficacy of N-Acetyl-Cysteine in Combination with Thiamphenicol in Sequential (Intramuscular/Aerosol) Therapy of Upper Respiratory Tract Infections Even When Sustained by Bacterial Biofilms

A total of 102 patients with recurrent upper respiratory tract infections underwent microbiological exploration with appropriate sampling and direct biopsies of the infected sites. Therapy was then started and on day 1 each patient received two intramuscular injections of thiamphenicol glycinate acetylcysteinate (TGA). From day 2 to 10 sequential therapy with the same drug was continued employing TGA administered by aerosol. All putative etiologic agents recovered were susceptible to thiamphenicol and only 24 demonstrated the ability to produce in vitro biofilms. The organisms comprised 10 Staphylococcus aureus, 6 Streptococcus pyogenes, 4 Streptococcus pneumoniae and 3 Haemophilus influenzae. Of the 24 subjects in whom biofilms were demonstrated to be present in vivo by Scanning Electron Microscopy, clinical and bacteriological cure was obtained in 21 cases (87.5%) following sequential therapy with TGA. Failures were considered to be persistent signs and symptoms at day 15 after initiation of treatment and lack of eradication of 3 S. aureus strains, despite their in vitro susceptibility to thiamphenicol. Very few adverse events attributable to TGA were reported in this cohort of patients. In no case was discontinuation of treatment deemed necessary by the attending physician.

Clinical applicability of Quantiferon-TB-Gold testing in psoriasis patients during long-term anti-TNF-alpha treatment: a prospective, observational study

BACKGROUND

Psoriasis patients who are treated with tumour necrosis factor (TNF)-alpha antagonists are at increased risk of reactivation of latent tuberculosis infection (LTBI) and should be adequately screened and monitored during active treatment.

OBJECTIVES

To evaluate in a prospective study, the performance of Quantiferon-TB-Gold in tube (QFT) in vitro assay compared to the conventional tuberculin skin test (TST) in detecting LTBI among a cohort of non-BCG-vaccinated patients with moderate-to-severe psoriasis during long-term treatment (12 months) with TNF-alpha antagonists.

METHODS

A total of 50 patients underwent QFT and TST testing at baseline and after 6 and 12 months of continuous anti-TNF-alpha treatment. Diagnosis of LTBI was made on the basis of a positive QFT result and negative chest-radiographic and microbiological assays. Patients with LTBI were subjected to standard isoniazid chemoprophylaxis and after 1 month, they resumed anti-TNF-alpha treatment with subsequent QFT and TST testing after 6 months. In all the cases, a follow-up period of 12 months was observed.

RESULTS

During the 12-month-study period, 14% of patients presented a QFT conversion. During active anti-TNF-alpha treatment, a QFT conversion was observed in 10% of patients (five cases). Agreement between QFT and TST was moderate (κ=0.408) at screening, good (κ=0.734) after 6 months and fair (κ=0.328) after 12 months of treatment. A total of 18% of patients presented a positive, discordant TST during the study period.

CONCLUSIONS

A single-test QFT-based screening strategy for LTBI in psoriasis patients receiving long-term anti-TNF-alpha treatment could reduce the incidence of false-positive LTBI cases, preventing unnecessary TB chemoprophylaxis.

Plasma cholinesterase correlations in acute surgical and critical illness

AIM

The properties of plasma cholinesterase (CHE) are partly undiscovered. Equally unknown are the correlations between changes in CHE and other blood variables during the acute phase response related to acute surgical and critical illness.

METHODS

Data from 432 measurements of CHE and other variables performed in 92 patients were systematically evaluated and processed by regression analysis.

RESULTS

There was a strong direct correlation between CHE and albumin (r=0.77, P<0.0001). CHE was also directly correlated to cholesterol, iron binding capacity, hematocrit, prothrombin activity, and inversely correlated to bilirubin and to presence of sepsis or liver dysfunction (P<0.0001 for all). Postoperatively CHE decreased to about 60% of the preoperative value, remaining directly related to it (r=0.69, P<0.0001), and decreasing further in the presence of sepsis or liver dysfunction, with slow reversal of the decrease during recovery from illness. In parenterally fed septic patients the decrease in CHE was moderated by increasing the amino acid dose (P<0.0001).

CONCLUSION

In acute surgical and critical illness CHE mostly behaves as a negative acute phase reactant, independently of the modifications related to other already known factors. This should be taken into account when interpreting the implications of decreased CHE in the clinical setting.

Liver resection for intrahepatic stones in congenital bile duct dilatation

OBJECTIVE

This study reports our clinical experience with liver resection for congenital dilatation of the intrahepatic bile duct and intrahepatic gallstones to evaluate results and define indications for treatment.

PATIENTS AND METHODS

We studied the clinical data of patients who underwent hepatic resection for intrahepatic lithiasis from January 1992 to December 2008 and assessed the immediate and long-term results of these interventions.

RESULTS

Of 49 treated patients, 47 underwent liver resection. In the majority of cases, the disease was limited to the left lobe and left hepatectomy was the most commonly performed surgical procedure. The operative mortality was zero with morbidity in 24.5% of patients. Cholangiocarcinoma was diagnosed in six cases (12.2%). In 91.6% of cases the long-term results were good or satisfactory.

CONCLUSION

Treatment goals in all cases should be the elimination of intrahepatic stones, the prevention of recurrent lithiasis, and prevention or cure of cholangiocarcinoma. Surgical excision is the best possible treatment for symptomatic patients with localized disease and atrophy of the affected liver.

Liver resections for hilar cholangiocarcinoma

Hilar cholangiocarcinoma (HC) is a rare tumor which has to be distinguished by intrahepatic cholagiocarcinoma invading hepatic hilum because the former has better prognosis then the latter. Patients with HC are difficult to manage because many challenging issues remain in the treatment of this tumour regarding correct diagnosis and therapeutic strategy. HC is resectable in about 30% of cases, but operative risk is highly influenced by septic complications of preoperative biliary drainage and by the need of major liver resection associated with biliary resection. We report the results of 43 resected patients (28 M/15 F; mean age 60 years, range 33-78), accounting for 29% of 149 patients with HC. Symptomless jaundice was the most common clinical presentation (87%; 130 patients). Biliary stricture was classified according to the Bismuth-Corlette classification as type 1 in 3 patients (7%); type 2 in 12 patients (28%); type 3 in 28 patients (65%). Ten patients underwent preoperative right portal vein embolization. Main biliary confluence excision associated with major hepatectomy was performed in 40 patients (93%), with R0 resection rate by 77%. Postoperative mortality rate was 6.9% (3 patients). Morbidity rate was 52.5% (21 patients), being biliary fistula (38%) and liver failure (19%) the most frequent complications. Five-year overall and disease-free survival rate were 36.1% and 28.2, respectively. Surgical resection remains the only chance of cure for patients with HC. However, due to the complexity of surgery immediate results remain unsatisfactory with morbidity and mortality rates higher than those reported after liver resection for other malignancies. This is mainly related to septic complications, strictly linked to complications of preoperative biliary drainage. Selective biliary drainage, careful management of biliary drains, drainage of excluded ducts in case of cholangitis, bile culture guided antibiotic use and preoperative portal vein embolization are important factors to reduce the risk of cholangitis and of postoperative complications. Because of the significant perioperative risk, the demanding operative management and the rarity of this tumor, patients with HC should be referred to tertiary surgical centers.

[Bacterial biofilm identification in the rhinopharingeal mucosa of children with recurrent infection of the upper respiratory tract and otitis media]

OBJECTIVE

The objective of the present study was to identify bacterial biofilms in tissue samples obtained from paediatric patients undergoing surgical treatment, for recurrent upper airway infections, frequently associated to effusive otitis media, unresponsive to repeated cycles of selective medical antibiotic and anti-inflammatory therapy and assay the ability of Haemophilus influenzae strains, most frequently identified in our cultural examinations, to grow as biofilm in vitro.

METHODS

We examined 18 surgical specimens (18 adenoids) from the upper respiratory tract, obtained from 18 paediatric patients. Tissues were cultured using conventional methods and subjected to scanning electron microscopy for detection of biofilm. Haemophilus influenzae strains, were cultured on 96-sterile well polystyrene microtiter plates (CELLSTAR-greiner bio-one) and stained with 1% crystal violet to quantify biofilm production.

RESULTS

Bacterial cocci attached to the tissue surface and organized in colonies, with a morphology consistent with bacterial coccoid biofilms, were observed in all adenoid (18/18) samples. Haemophilus influenzae isolates from 11/18 (61.1%) of our tissue samples scored a percentual transmittance (%Tbloc) > 50, identifying a high capacity to form biofilms (level 4).

CONCLUSIONS

Bacterial biofilms identified in adenoid tissue of paediatric patients with recurrent upper airway inflammatory processes, associated to chronic effusive otitis media, may represent a bacterial "reservoir" responsible of the maintenance of chronic inflammatory mucosal reactions, resistant to selective antibiotic therapy and requiring surgical treatment.

Biofilm formation by Haemophilus influenzae isolated from adeno-tonsil tissue samples, and its role in recurrent adenotonsillitis

Aim of the present study was to identify bacterial biofilms in tissue samples obtained from paediatric patients undergoing surgical treatment, for chronic and recurrent adeno-tonsillitis, not responding to repeated cycles of selective medical antibiotic and anti-inflammatory treatment and to assay the ability of Haemophilus influenzae strains, most frequently identified in the culture examinations, to grow as biofilm in vitro. Overall, 25 surgical specimens (15 adenoids, 10 tonsils) were examined from the upper respiratory tract, from 15 paediatric patients (mean age 6 years). All patients were affected by recurrent and/or chronic adenoiditis and adenotonsillitis unresponsive to selective antibiotic and anti-inflammatory therapy. Tissues were cultured using conventional methods and subjected to scanning electron microscopy for detection of biofilm. Haemophilus influenzae strains, were cultured on 96-sterile well polystyrene microtitre plates (CELLSTAR-greiner bio-one) and stained with 1% crystal violet to quantify biofilm production. Bacterial cocci attached to the tissue surface and organized in colonies, with a morphology consistent with bacterial coccoid biofilms, were observed in all adenoid (15/15) and in 6/10 tonsil samples. Haemophilus influenzae isolates from 12/25 (48%) of our tissue samples scored a percent transmittance (%T(bloc)) > 50, displaying a high capacity to form biofilms (level 4). In conclusion identification of bacterial biofilms in chronic and/or recurrent paediatric upper airway inflammatory processes and the capacity to produce biofilm in vitro, demonstrated by Haemophilus influenzae (the most frequently identified bacteria in our samples), could be related to the aetiopathogenic role of biofilms in chronic inflammatory mucosal reactions and to the resistance of these infections to selective antibiotic therapy.

Liver resections for hepatocellular carcinoma in chronic liver disease: experience in an Italian centre

AIM

Liver resection (LR) and transplantation are the best options for treatment of hepatocellular carcinoma (HCC). We retrospectively analysed the experience obtained with LR for HCC in chronic liver disease patients.

METHODS

Up until May 2005, 248 patients with HCC were evaluated, and 113 resected. Of these, 97 with chronic liver disease, who underwent a total of 100 resections, form the basis of this study. Age of the patients was 65.6+/-9.2 years (range 32-81, male/female 76/21). In 77 cases there was unifocal and in 23 multinodular tumour; in 61 the size of the tumours was < or =5 cm and in 39>5 cm. Limited resections were performed in 15 cases, resections of 1-2 segments in 51, and major hepatectomies in 34.

RESULTS

Blood transfusions were required in 28 cases. Three patients died postoperatively, from liver failure and/or sepsis. Seventeen patients had nonlethal complications (mostly liver dysfunction, often with signs of amplified inflammatory response, including ARDS, without evident sources of sepsis). The 5- and 10-year survival rates were 44% and 24%, respectively. Decreased survival was significantly related to increasing number of tumour nodules and degree of liver fibrosis/presence of cirrhosis, and with the expression of markers of carcinogenesis in a sub-group who received this assessment. At 5 years the rate of liver HCC recurrence was 46%, however, death was unrelated to recurrence in 41% of non-survivors.

CONCLUSIONS

Surgery for HCC achieves acceptable early and long-term results. However, the patterns affecting perioperative outcome must be better understood, and the high recurrence rate warrants further trials to assess preventive treatments after LR.

Recurrent upper airway infections and bacterial biofilms

BACKGROUND

Bacterial biofilms identified in various medical devices used in otorhinolaryngology, including tympanostomy tubes, voice prostheses, and cochlear implants, can directly colonise mucosal tissues. The upper airways seem to be at high risk for this type of colonisation. Chronic and/or recurrent upper airway infections may be related to the complex structural and biochemical (quorum sensing) organisation of the biofilm which interferes with the activity of antibiotics (including those with proven in vitro efficacy), thus promoting the establishment of a chronic infection eradicable only by surgical treatment. Biofilm formation plays a role in upper respiratory infections: it not only explains the resistance of these infections to antibiotic therapy but it also represents an important element that contributes to the maintenance of a chronic inflammatory reaction.

OBJECTIVES

To document the presence of biofilms in surgical tissue specimens from patients with recurrent infection diseases, and identify their possible role in the chronicity of these infectious processes.

METHOD

We examined 32 surgical specimens from the upper respiratory tract (tonsils, adenoids, mucosa from the ethmoid and maxillary sinuses) of 28 patients (20 adults, eight children) with upper airway infections that had persisted despite repeated treatment with anti-inflammatory agents and antibiotics with demonstrated in vitro efficacy. Tissues were cultured using conventional methods and subjected to scanning electron microscopy for detection of biofilm formation.

RESULTS

Over 80 per cent (26/32; 81.3 per cent) of the tissue specimens were culture-positive. Bacterial biofilms (associated in most cases with coccoid bacteria) were observed in 65.6 per cent of the tissue samples.

The relationship between albumin, other plasma proteins and variables, and age in the acute phase response after liver resection in man

A large series of plasma albumin (ALB, g/dl) and simultaneous blood and clinical measurements were prospectively performed on 92 liver resection patients, and processed to assess the correlations between ALB, other plasma proteins, additional variables and clinical events. The measurements were performed preoperatively and at postoperative day 1, 3 and 7 in all patients, and subsequently only in those who developed complications or died. In patients who recovered normally ALB was 4.3 +/- 0.4 g/dl (mean +/- SD) preoperatively, 3.7 +/- 0.7 at day 1 and 3, and 3.9 +/- 0.4 at day 7. In patients with complications its decrease was more prolonged. In non-survivors it was 3.4 +/- 0.4 preoperatively, 3.0 +/- 0.4 at day 1, and then decreased further. Regression analysis showed direct correlations between ALB and pseudo-cholinesterase (CHE, U/l, nv 5300-13000), cholesterol (CHOL, mg/dl), iron binding capacity (IBC, mg/dl), prothrombin activity (PA, % of standard reference) and fibrinogen, an inverse correlation with blood urea nitrogen (BUN, mg/dl) for any given creatinine level (CREAT, mg/dl), and weaker direct correlations with hematocrit, other variables and dose of exogenous albumin. An inverse relationship found between ALB and age (AGE, years) became postoperatively (POSTOP) also a function of outcome, showing larger age-related decreases in ALB associated with complications (COMPL: sepsis, liver insufficiency) or death (DEATH). Main overall correlations: CHE = 287.4(2.014)(ALB), r = 0.73; CHOL = 16.5(1.610)(ALB) (1.001)(ALKPH), r = 0.71; IBC = 68.6(1.391)(ALB), r = 0.64; PA = 13.8 + 16.0(ALB), r = 0.51; BUN = 21.3 + 20.2(CREAT) - 6.2(ALB), r = 0.91; ALB = 5.0-0.013(AGE) - {0.5 + 0.003(AGE)( COMPL ) + 0.012(AGE)( DEATH )}( POSTOP ), r = 0.74 [p < 0.001 for each regression and each coefficient; ALKPH = alkaline phosphatase, U/l, nv 98-279, independent determinant of CHOL; discontinuous variables in italics label the change in regression slope or intercept associated with the corresponding condition]. These results suggest that altered albumin synthesis (or altered synthesis unable to compensate for albumin loss, catabolism or redistribution) is an important determinant of hypoalbuminemia after hepatectomy. The correlations with age and postoperative outcome support the concept that hypoalbuminemia is a marker of pathophysiologic frailty associated with increasing age, and amplified by the challenges of postoperative illness.

The Sentinel Project: an update on the prevalence of antimicrobial resistance in community-acquired respiratory Streptococcus pneumoniae and Haemophilus spp. in Italy

A total of 460 Streptococcus pneumoniae and Haemophilus spp. collected from respiratory infections during 2000 was tested for their susceptibility to 15 selected antibiotics. Overall, penicillin resistance among pneumococci was 10.5%, while lack of susceptibility to macrolides, co-trimoxazole, tetracycline and chloramphenicol reached 35.2%, 26.2%, 22.6% and 6.0%, respectively. Amoxicillin/clavulanic acid and levofloxacin were the most potent compounds (100% and 99.9% susceptible strains, respectively). Among isolates of Haemophilus influenzae and Haemophilus parainfluenzae, beta-lactamase production (12.5% and 10%, respectively), and co-trimoxazole (19.9% and 40.0%) and clarithromycin (11.2% and 40.0%) resistance were the prevalent threats. This study confirms the trend observed in Italy since 1992: macrolide resistance among respiratory microorganisms is increasing, while several drugs including amoxicillin/clavulanic acid, third generation injectable cephalosporins and fluoroquinolones remain active on the great majority of these pathogens.

A less invasive, selective, functional neck dissection for papillary thyroid carcinoma

HYPOTHESIS

To describe an alternative lateral neck access in order to perform neck dissection in papillary thyroid carcinoma (PTC) with lymph node involvement.

DESIGN

Prospective (January 2000 to December 2003), 36-month study.

SETTING

Catholic University of Rome and University of "Tor Vergata", Rome, Italy.

PATIENTS AND METHODS

Twenty-four consecutive patients with PTC and cervical lymph node metastases were included. Functional neck dissection (FND), unilateral or bilateral, was performed acceding via a lateral dissection through a traditional Kocher incision, running along the superficial fascia of the neck and posteriorly to the sternocleidomastoideus muscle.

RESULTS

Mean age was 39.04+/-13.69 years. Twenty patients were women and four were men. Mean tumour size was 2.5+/-1 cm, while the greatest metastatic lymph node size was 4.5 cm. Minimally invasive, selective FND was performed in all patients associated to total thyroidectomy and central compartment lymph node clearance. Metastatic lymph nodes were found in 142 out of 340 of the lymph nodes dissected.

CONCLUSIONS

Minimally invasive neck dissection seems to carry a lower risk in terms of specific morbidity and allows a quicker recovery and a better aesthetic result. This access has to be considered as a less invasive procedure compared to the other surgical accesses for the radical or modified lateral neck dissection.

No Evidence of Hematopoietic Stem Cell Mobilization in Patients Submitted to Hepatectomy or in Patients With Acute on Chronic Liver Failure

BACKGROUND

Liver regeneration is a heterogeneous phenomenon involving the proliferation of different cell lineages in response to injury. Under a strong positive selection pressure bone marrow derived stem cells may be involved in this process, by making a contribution to both parenchymal restoration and endothelial cell replacement. We investigate bone marrow stem cell migration to the liver in patients undergoing hepatectomy or with acute on chronic liver failure.

METHODS

We enrolled 6 patients submitted to hepatectomy, 6 patients to cholecystectomy and 8 patients with acute decompensation of liver cirrhosis. Mobilization of CD34+ cells was evaluated by cytofluorimetry on peripheral blood samples at different time points; baseline, 1, 3, 7, 15 and 30 days after surgery and at admission, 1, 7 and discharge among patients with acute on chronic liver failure. 10 healthy subjects undergoing blood donation were also enrolled to evaluated the basal value of CD34+ cells.

RESULTS

White blood cell counts remained in the normal range (4.1-9.8 x 10(9)/L) in all groups throughout the follow-up. In all patients of Groups 1, 2 and 3, circulating CD34+ failed to show statistically significant differences both as the absolute number and as the percentage at any time point compared to healthy controls.

CONCLUSIONS

Bone marrow derived cell mobilization can not be detected after hepatectomy or during an acute decompensation on a cirrhotic liver. Under these circumstances liver regeneration can probably call upon mature hepatocytes and endogenous progenitor cells. The involvement of extrahepatic progenitors if any, is a rare and limited phenomenon.

Antimicrobial susceptibility profiles of Pseudomonas aeruginosa and Staphylococcus aureus isolated in Italy from patients with hospital-acquired infections

Here we report the results of the Sentinel Project 2000 and give the susceptibility to selected antibiotics of 108 Pseudomonas aeruginosa and 108 Staphylococcus aureus strains isolated from patients with hospital-acquired lower respiratory tract infections. In P. aeruginosa, susceptibility to aztreonam and ciprofloxacin was lower than 50%. The resistance rate to beta-lactams was up to 25% and to amikacin 15.7%. Blood isolates showed 80-90% susceptibility to all antibiotics tested except for aztreonam and tobramycin. Overall, oxacillin resistance in S. aureus was 45%, reaching 64.3% among the bronchoalveolar lavage isolates, and 42.9% among the blood isolates. These worrying results confirm the need for continuous monitoring of bacterial resistance trends in the hospitals, mainly in ICUs.

Modified radical neck dissection via extra-thyroideal space (MRND vets) in papillary thyroid carcinoma

The purpose of this study was to describe an alternative lateral neck access to perform lymph nodes sampling and/or neck dissection via extra-thyroideal space (MRND vets) in papillary thyroid carcinoma with lymph nodes involvment. Twenty-four consecutive patients with papillary thyroid carcinoma were included. Lymph nodes sampling and modified radical neck dissection, unilateral or bilateral, were performed acceding via a lateral dissection through a traditional Kocher incision, running along the medial fascia of the neck, posteriorly to the sterno-cleido-mastoideus muscle (SCM). Mean age was 39.04 +/- 13.69 years. Twenty patients were women, and 4 were men. Mean tumor size was 2.5 +/- 1 cm.. Total thyroidectomy with lymph nodes dissection of the central compartment associated to modified radical neck dissection was performed in 17 patients: among these, nine patients had a preoperative diagnosis of the latero-cervical lymph nodes metastases, and eight had a perioperative diagnosis of metastases of the extensive sampling of the lower third of the jugular chain. Metastatic lymph nodes were found in 107 out of 615 lymph nodes dissected. The MNRD vets access for modified lateral neck dissection seems to carry a lower risk in terms of specific morbility and allows a quicker recovery and a better cosmetic result. This access has to be considered as a less invasive procedure compared to other surgical accesses for the radical modified lateral neck dissection.

[Experimental model of hepatic tumor in the rat: description and results of intrahepatic implantation technique]

In order to investigate new therapeutic strategies for hepatocellular carcinoma (HCC), an animal model easily reproducible of hepatic tumor is necessary. Several techniques of intrahepatic tumor implantation have been reported in the literature. Many of them have the disadvantage of high rate of artificial neoplastic extrahepatic dissemination, both peritoneal and systemic. These drawbacks interfere with the evaluation of treatment efficacy. In this study we describe a modified technique of intrahepatic tumor implantation in the rat, previously reported by Yang in 1992, which is based on the insertion in the liver, after neoplastic tissue, of a piece of hemostatic sponge (Spongostan) that permits to significantly reduce the rate of artificial neoplastic dissemination. Nine ACI/T rats were used and Morris hepatoma 3924A was implanted in the right hepatic lobe. In all cases an intrahepatic tumor take was documented by MRI and by histological examination. No lung metastases were observed. In only one animal peritoneal and subcutaneous nodules were seen, likely due to a technique mistake. According to tumor growth curve it is possible to observe that, with this technique, a 1 cm tumor nodule is obtainable 10 days after the implantation, without extrahepatic metastases, easily detectable by imaging techniques such as MRI used in this study. In conclusion this modified technique of intrahepatic tumor implantation permits to obtain an intrahepatic tumor animal model which is easily reproducible and suitable for the evaluation of efficacy of experimental therapies for HCC.

Coexistence of a parathyroid adenoma and parathyroid cyst causing primary hyperparathyroidism

The association of a functional parathyroid cyst with a parathyroid adenoma is an uncommon finding. In this report we describe the clinical history of a 60-yr-old man, presenting with the following findings: hypercalcemia (18.9 mg/dl), elevated serum parathormone levels (1320 pg/dl), hypercalciuria (228 mg/dl), and hyperphosphaturia (155 mg/dl). Neck ultrasound, magnetic resonance imaging (MRI) and 99Tc Sestamibi scintigraphy led to the identification of a left parathyroid adenoma, located at the lower pole of the left thyroid gland lobe, associated with a parathyroid cyst, located at the upper extremity of the same thyroid lobe. Parathyroidectomy was performed and the histological examination confirmed the diagnosis of a parathyroid adenoma with aspects of cystic degeneration and an upper parathyroid cyst. Analysis of the crystal clear intracystic fluid showed elevated parathyroid hormone (PTH) levels (137.000 pg/ml). The patient is normocalcemic at 2 yr after surgery without signs of recurrent parathyroid enlargements. Aetiology, diagnosis and management of parathyroid cyst will be discussed.

[Bacterial pneumonia in HIV-infected patients]

This case-control study assessed risk factors and prognostic indicators of 350 episodes of bacterial pneumonia in 285 HIV-infected patients. On univariate analysis, intravenous drug abuse (p<0.001), regular cigarette smoking (p<0.001), cirrhosis (p=0.04), and history of a previous episode of pneumonia (p=0.04), were risk factors for community-acquired episodes of bacterial pneumonia, whereas length of hospitalization (p=0.01) was a risk factor only for nosocomial bacterial pneumonia. The small amount of circulating T CD4+ cells, (<100/mmc) was a risk factor in both groups of pneumonia (p<0.05). Stepwise logistic regression analysis revealed that IVDA in community-acquired episodes and low levels of circulating T CD4+ cells, both in community-acquired and hospital-acquired episodes, were independent risk factors for the development of bacterial pneumonia. The case-fatality rate observed in our study was 27%. On stepwise logistic regression analysis, T CD4+ cell counts >100/mmc (p<0.02), neutropenia (p=0.04), PO2 arterial level <70 mmHg (p=0.01), and Karnofsky score <50 (p=0.04) were independent indicators of mortality. According to a personally developed prognostic score, 211 episodes of pneumonia (60%) were classified as mild, 63 (18%) as moderate, and 76 (22%) as severe. Clinicians must carefully evaluate those variables that can influence the prognosis of bacterial pneumonia to make early identification of affected patients and to promptly establish the most appropriate therapeutic strategy in each case.

Evaluation of BACTEC Mycobacteria Growth Indicator Tube (MGIT 960) automated system for drug susceptibility testing of Mycobacterium tuberculosis

The reliability of the BACTEC MGIT 960 system, an automated version of the Mycobacteria Growth Indicator Tube (MGIT), for antimicrobial susceptibility testing of Mycobacterium tuberculosis was evaluated on 78 clinical isolates. Rifampin (RMP), isoniazid (INH), streptomycin (SM), and ethambutol (EMB) were tested at the following concentrations: 1.0 microg/ml for RMP, 0.1 and 0.4 microg/ml for INH, 1.0 and 4.0 microg/ml for SM, and 5.0 and 7.5 microg/ml for EMB. Results were compared with those obtained by the BACTEC 460 TB radiometric system. Initially the reproducibility study showed 99.5% agreement on repeat testing with all the four drugs. With susceptibility testing of clinical isolates, excellent agreement between the two systems was found for all the drugs. A total of nine major errors were observed for only three isolates, resistant according to BACTEC MGIT 960 and susceptible according to BACTEC 460 TB, to SM (4.0 microg/ml), INH (0.1 microg/ml), and EMB (5.0 microg/ml) (one isolate) and to SM (1.0 microg/ml), INH (0.4 microg/ml), and EMB (5.0 microg/ml) (two isolates). When these isolates were tested by using the conventional proportion method on Löwenstein-Jensen medium, agreement with BACTEC MGIT 960 was found for five results and with BACTEC 460 TB for the remainder. The time to report results was 7.9 days by MGIT 960 and 7.3 days by BACTEC 460 TB, which was not found statistically significant (P > 0.05). In conclusion, the performance of BACTEC MGIT 960 was found similar to that of BACTEC 460 TB and this new system can be considered a good alternative to the radiometric method for routine susceptibility testing of M. tuberculosis.

Follicular adenoma of the thyroid gland with extensive bone metaplasia

Follicular adenomas of the thyroid account for over 90% of benign neoplasms of the gland. They exhibit a wide range of morphological structures, from the classical follicular pattern to the peculiar hyalinizing trabecular pattern. Although follicular adenomas grow slowly, they are nonetheless subject to degenerative, most often hemorrhagic changes in their central portion. These hemorrhagic areas undergo further regressive changes such as sclerosis and calcification. However, the detection of a true bone formation with a trabecular structure and the presence of marrow is a very rare occurrence. A follicular adenoma with central cartilaginous metaplasia has been reported in literature but, to our knowledge, a follicular adenoma with bone metaplasia has never been described.

Changes in incidence and risk factors of Mycobacterium avium complex infections in patients with AIDS in the era of new antiretroviral therapies

The aim of the study presented here was to determine the incidence, risk factors and prognostic indicators of Mycobacterium avium complex (MAC) infection in HIV-infected subjects prior to and after the introduction of highly active antiretroviral therapy (HAART). In the HAART era, the incidence of MAC infection decreased significantly from 3.7 to 0.9 per 100 person-years. Using logistic regression analysis, a high acute physiology and chronic health evaluation (APACHE) III score, a low number of CD4+ cells/ mm3 and a high level of HIV viremia were found to be independent predictors of the risk to develop MAC disease; however, a high APACHE III score was the only prognostic indicator associated with an unfavourable outcome of a disseminated MAC infection. These results indicate that MAC infections, although considerably less frequent in the HAART era, are still responsible for cases of severe disease.

Nosocomial bacterial pneumonia in human immunodeficiency virus infected subjects: incidence, risk factors and outcome

The presented study examined the incidence, risk factors and outcome of nosocomial bacterial pneumonia (NBP) in human immunodeficiency virus (HIV)-infected subjects. Forty-two cases of NBP were ascertained by a 5-yr prospective surveillance and were matched to 84 controls. NBP incidence was 10.8 per 10,000 hospital patient-days. In particular, the incidence of NBP was 13.9 per 10,000 patient-days in the period 1994-1996 and 5.6 per 10,000 patient-days in the period 1997-1998 (p=0.01). By using regression analysis, predictors for developing NBP were an increasing value of Acute Physiology and Chronic Health Evaluation (APACHE) III score (p<0.01) and the presence of acquired immune deficiency syndrome (AIDS)-related central nervous system (CNS) diseases (p=0.01). The additional hospital stay attributable to NBP was 15 days. The attributable mortality rate was estimated to be 29%. Nosocomial bacterial pneumonia is more common in patients with advanced human immunodeficiency virus infection, high Acute Physiology and Chronic Health Evaluation III score and central nervous system diseases. Although the incidence of nosocomial bacterial pneumonia, as well of other opportunistic infections, decreased considerably in the era of highly active antiretroviral therapy, it still represents an important cause of mortality.

Isolation and identification of Mycobacterium neoaurum from a patient with urinary infection

Mycobacterium neoaurum is a novel species of Mycobacteria, until now only isolated from catheters in immunosuppressed patients. This report describes the isolation and identification of M. neoaurum from urine obtained from a hospitalized patient.

Fatal pulmonary infection due to multidrug-resistant Mycobacterium abscessus in a patient with cystic fibrosis

We report a case of fatal pulmonary infection caused by Mycobacterium abscessus in a young patient with cystic fibrosis, who underwent bipulmonary transplantation after a 1-year history of severe lung disease. Fifteen days after surgery he developed septic fever with progressive deterioration in lung function. M. abscessus, initially isolated from a pleural fluid specimen, was then recovered from repeated blood samples, suggesting a disseminated nature of the mycobacterial disease. Drug susceptibility testing assay, performed on two sequential isolates of the microorganism, showed a pattern of multidrug resistance. Despite aggressive therapy with several antimycobacterial drugs, including clarithromycin, the infection persisted, and the patient died.

Brief report: disseminated mycobacteriosis caused by drug-resistant Mycobacterium triplex in a human immunodeficiency virus-infected patient during highly active antiretroviral therapy

Mycobacterium triplex is a novel species that, until now, has been isolated only from limited clinical samples, and its clinical relevance has been largely unknown. In this report, we describe the first case of disseminated disease caused by M. triplex in a human immunodeficiency virus-infected patient.

Comparison of the mycobacteria growth indicator tube with radiometric and solid culture for isolation of mycobacteria from clinical specimens and susceptibility testing of Mycobacterium tuberculosis

We compared the mycobacteria growth indicator tube (MGIT) system with the BACTEC 460 TB and Loewenstein-Jensen (LJ) systems for the recovery of mycobacteria (acid-fast bacilli [AFB]) from 600 clinical specimens. A total of 50 AFB (32 Mycobacterium tuberculosis complex, 10 M. avium complex, 3 M. gordonae, 3 M. xenopi, 1 M. terrae and 1 M. fortuitum) were detected. MGIT recovered 50 isolates of AFB (100% sensitivity), and BACTEC 460 TB and LJ recovered 49 (98% sensitivity) and 19 (38% sensitivity) AFB isolates, respectively. The mean times to detect mycobacteria were 10, 10 and 25 days for MGIT, BACTEC 460, and LJ slants. All isolates of M. tuberculosis complex were tested for susceptibility to streptomycin, isoniazid, rifampin, and ethambutol with the MGIT and BACTEC 460 TB. Both systems yielded identical susceptibility data with different mean times to report (5.38 days for MGIT versus 7.33 days for BACTEC 460 TB, P<0.05). The results suggest that MGIT is equivalent to BACTEC 460 TB in its ability to support the growth of mycobacteria, but significantly more efficient than LJ. MGIT may also be used for susceptibility testing of primary antituberculosis drugs.

Surgery of differentiated thyroid carcinoma, lymph node metastases and locoregional recurrence

Surgery of differentiated thyroid carcinoma is burdened with risk factors that significantly impact on prognosis, as age at diagnosis and tumor stage. Problems involved concern the extent of surgical resection and the indication for regional lymphadenectomy. As for the former, the most popular approach is total thyroidectomy "on principle" with neck lymphadenectomy. Lobectomy may represent an alternative to total thyroidectomy in low risk patients with unifocal papillary carcinoma 1 cm or less in size, or minimally invasive follicular carcinoma. As for lymphadenectomy, most authors do not agree with surgery "on principle" but rather "of necessity", that is, in presence of clinically evident lymphadenopathy and neck lymphadenectomy is the preferred surgical strategy. In most cases surgery is the treatment of choice of locoregional recurrence. Careful preoperative work-up and accurate surgical procedure are mandatory.

Application of molecular methods for detection and transmission analysis of mycobacterium tuberculosis drug resistance in patients attending a reference hospital in Italy

A molecular analysis of drug-resistant isolates of Mycobacterium tuberculosis was done in a population with a high prevalence of human immunodeficiency virus infection. Seventy-one consecutive isolates were tested for genotypic resistance to isoniazid, rifampicin, streptomycin, and ethambutol by polymerase chain reaction-single strand conformation polymorphism analysis and automated sequencing of target regions. Phenotypic and genotypic resistance to isoniazid, rifampicin, streptomycin, and ethambutol were detected in 23.4%, 11.2%, 7%, and 5.6% of isolates and in 87%, 88%, 40%, and 100% of resistant isolates, respectively. Specificity was 100% for all target regions. When rpoB, katG, and ahpC mutation analysis were combined, 86% of resistant isolates to any drug were identified. No mutations in inhA were found in isoniazid-resistant isolates. Molecular detection of drug resistance, particularly for isoniazid and rifampicin, may represent a sensitive and very specific technique. The strategy of selecting rpoB, katG, and ahpC to quickly identify most resistant isolates, with a relevant saving of resources, is warranted.

Polymerase chain reaction-reverse cross-blot hybridization assay in the diagnosis of sporotrichoid Mycobacterium marinum infection

In this paper, we report a patient in whom Mycobacterium marinum sporotrichoid infection was diagnosed using polymerase chain reaction (PCR) amplification of the 16S rRNA gene and subsequent analysis of the amplified product in a reverse cross-blot hybridization assay with mycobacterial species-specific probes. This molecular method allowed us rapidly to detect and identify this organism directly in the patient's lesional skin biopsy rather than in cultures in conventional media. The identification provided by PCR-reverse cross-blot hybridization assay was confirmed by examination of the morphological and biochemical features and by high-performance liquid chromatography analysis of mycolic acid from the clinical isolate, suggesting the validity of our molecular approach.

Routine use of PCR-reverse cross-blot hybridization assay for rapid identification of Mycobacterium species growing in liquid media

A PCR-reverse cross-blot hybridization assay procedure that is able to rapidly identify 13 species of clinically relevant mycobacteria was evaluated for routine use in the identification of acid-fast isolates growing in BACTEC 460 TB (12B and 13A) and BACTEC 9000 MB (Myco/F) liquid media. Eight of the probes used were already described by Kox et al. (L. F. F. Kox et al., J. Clin. Microbiol. 33:3225-3233, 1995). In addition, we used six other probes specific for M. chelonae, M. malmoense or M. szulgai, M. genavense, M. gordonae, M. terrae, and M. marinum/M. ulcerans that we designed ourselves. This procedure allowed us to identify 459 mycobacterial species directly from broth cultures of 5,466 clinical samples collected over 1 year and processed with the radiometric or nonradiometric BACTEC system. Our results were in agreement with those obtained by conventional identification methods and also with those obtained by mycolic acid analysis by high-performance liquid chromatography. This assay seems to be a reliable procedure for the routine identification of mycobacteria, providing an accurate identification of mycobacterial isolates more rapidly than conventional tests, with remarkable implications for an efficacious specific antimycobacterial therapy.

Bacterial pneumonia in HIV-infected patients: analysis of risk factors and prognostic indicators

This case control study assessed risk factors and prognostic indicators of 350 episodes of bacterial pneumonia in 285 HIV-infected patients. On univariate analysis, intravenous drug abuse (i.v.DA; p < .001 versus controls), regular cigarette smoking (p < .001), cirrhosis (p = .04), and history of a previous episode of pneumonia (p = .04) were risk factors for community-acquired episodes of bacterial pneumonia, whereas length of hospitalization (p = .01) was a risk factor only for nosocomial bacterial pneumonia. The small amount of circulating T CD4+ cells (<100/ mm3) was a risk factor in both groups of pneumonia (p < .05). Stepwise logistic regression analysis revealed that i.v.DA in community-acquired episodes and low levels of circulating T CD4+ cells, both in community-acquired and hospital-acquired episodes, were independent risk factors for the development of bacterial pneumonia. The case-fatality rate observed in our study was 27%. On stepwise logistic regression analysis, T CD4+ cell counts < or = 100/mm3 (p = .02), neutropenia (p = .04), PO2 arterial level < or = 70 mm Hg (p = .01), and Karnofsky score < or = 50 (p = .04) were independent indicators of mortality. According to a personally developed prognostic score, 211 episodes of pneumonia (60%) were classified as mild, 63 (18%) as moderate, and 76 (22%) as severe. Clinicians must carefully evaluate those variables that can influence the prognosis of bacterial pneumonia to make early identification of affected patients and to promptly establish the most appropriate therapeutic strategy in each case.

Evaluation of the Abbott LCx Mycobacterium tuberculosis assay in comparison with culture methods in selected Italian patients

A ligase chain reaction (LCR) DNA amplification method for the molecular diagnosis of Mycobacterium tuberculosis (Abbott LCx MTB) was evaluated in comparison with solid and liquid phase culture on 622 selected samples collected in two large Italian hospitals, of which 310 obtained from HIV-1 positive patients and 312 from HIV-negative individuals. The overall prevalence of mycobacteria by culture was 22% (137/622), and the apparent sensitivity and specificity of LCx vs. culture were 87.6% and 98.2%. Of the 26 culture positive/LCx negative samples, 22 were positive for MOTT and 4 for M. tuberculosis. All 9 samples positive by LCx and negative by culture were classified as true positive by clinical criteria. The final values of sensitivity, specificity, positive predictive value and negative predictive value for LCx rose to 96.8%, 100%, 100% and 99.2%, respectively. The adjusted sensitivity of culture methods was 89.5% for solid phase and 92.7% for Bactec. In view of the high sensitivity on both smear-positive (100%) and smear-negative (92.4%) samples and of the high negative predictive value, the LCR-based amplification method appears suitable as a routine screening method for the rapid diagnosis of M. tuberculosis in high-risk patients.