Model-based signal processing enables bidirectional inferring between local field potential and spikes evoked by noxious stimulation

BACKGROUND

Recording spontaneous and evoked activities by means of unitary extracellular recordings and local field potential (LFP) are key understanding the mechanisms of neural coding. The LFP is one of the most popular and easy methods to measure the activity of a population of neurons. LFP is also a composite signal known to be difficult to interpret and model. There is a growing need to highlight the relationship between spiking activity and LFP. Here, we hypothesized that LFP could be inferred from spikes under evoked noxious conditions.

METHOD

Recording was performed from the medullary dorsal horn (MDH) in deeply anesthetized rats. We detail a process to highlight the C-fiber (nociceptive) evoked activity, by removing the A-fiber evoked activity using a model-based approach. Then, we applied the convolution kernel theory and optimization algorithms to infer the C-fiber LFP from the single cell spikes. Finally, we used a probability density function and an optimization algorithm to infer the spikes distribution from the LFP.

RESULTS

We successfully extracted C-fiber LFP in all data recordings. We observed that C-fibers spikes preceded the C-fiber LFP and were rather correlated to the LFP derivative. Finally, we inferred LFP from spikes with excellent correlation coefficient (r = 0.9) and reverse generated the spikes distribution from LFP with good correlation coefficients (r = 0.7) on spikes number.

CONCLUSION

We introduced the kernel convolution theory to successfully infer the LFP from spikes, and we demonstrated that we could generate the spikes distribution from the LFP.

Non cross-linked equine collagen (Salvecoll-E gel) for treatment of complex ano-rectal fistula

BACKGROUND

Fistula-in-ano is one of the most commonly presenting anorectal diseases. Sphincter sparing treatment options should be considered in patients with complex fistulas. Salvecoll-E gel is a native collagen deantigenated and purified, non-cross-linked equine dermal extract, with an amino acid composition identical to human collagen.

METHODS

The multicentric trial study was a prospective, single-arm observational clinical study with the objective to assess the efficacy of Salvecoll-E gel for anal fistula repair in 70 patients. All patients had undergone preliminary surgical treatment consisting of positioning of a draining loosing seton that was maintained for a period of 4-6 weeks. After seton removal, a gentle debridement and washing of the fistula track was performed. The scar tissue was removed from the internal orifice. Internal opening was covered by a side-to side mucosal suture. Salvecoll-E was injected through the external opening into the fistula track, the external opening it has been opened.

RESULTS

Twelve months after surgery, 55 patients demonstrated a clinically healed fistula (78,5%), 15 patients have a recurrence (21,5%). Most of the recurrences were observed in the first 6 months of treatment (13/15, 86.6%). We don't observe any worsening in CCF score. The results obtained at 1 year certainly seem satisfactory and in line with the best results published in literature using mini-invasive techniques.

CONCLUSION

Salvecoll-E gel is a promising non-invasive technique for conservative treatment of anal fistulas, it's well tolerated by the patients and, in case of recurrence, reinjection or all other known techniques are feasible.

Lymphatic Mapping and Sentinel Node Identification in Squamous Cell Carcinoma and Melanoma of the Head and Neck

Aim

The aim of our study was to evaluate the role of scintigraphy in lymphatic mapping and in the identification of the sentinel lymph node (SLN) in patients with head and neck cancer.

Methods

Between September 1999 and February 2001 we enrolled 22 consecutive patients with cancer in the head and neck region: five squamous cell carcinomas, one Merkel cell tumor of the cheek, and 16 malignant melanomas. Lymphoscintigraphy was performed three hours before surgery after injection of 30-50 MBq of 99mTc-Nanocoll in 0.3 mL; the dose was fractionated by injecting the radiotracer at two points around the lesion. Static acquisition (anterior and/or lateral views, 512 × 512 matrix, 5 mins pre-set time) was started immediately after the injections so as to visualize the pathways of lymphatic drainage. The skin projection of the SLN was marked with ink. Intraoperative SLN detection was performed with perilesional injection of patent blue.

Results

SLNs were found with lymphoscintigraphy in all patients. Thirty-three SLNs were identified: one occipital node, three nodes at the base of the tongue, 10 superficial lateral nodes (external jugular), five submandibular nodes, five submental nodes, three mastoid nodes and six supraclavicular nodes. Biopsy was performed in 21/22 patients. In 20/22 patients the first lymph nodes were visualized in the proximal cranial regions (retroauricular, jugular and submandibular) at five minutes post injection. The SLN positivity rate was 13.6% (three patients). All patients with tumor-positive SLNs were submitted to radical dissection. Poor concordance in the detection of sentinel nodes was observed with patent blue.

Conclusions

The flow of nanocolloid in the lymph vessels of the head is rapid. In our experience immediate scintigraphic imaging was essential to visualize the pathways of lymphatic drainage and the first SLN. Radioguided SLN biopsy is therefore recommended within three hours. Injection of patent blue is inadvisable because of the poor concordance with lymphoscintigraphy and the risk of permanent tattooing of the face.

Sentinel Node Biopsy for Malignant Melanoma: Analysis of a Four-Year Experience

Aims and background

Sentinel node (SN) biopsy has been introduced to solve the controversy concerning the effectiveness of prophylactic lymphadenectomy in intermediate thickness melanoma. The aim of this study was to evaluate the rate of metastases, the technical details of the procedure, and the main reasons of failure.

Methods

235 patients affected by intermediate thickness melanoma (tumor thickness >0.75 mm and <4 mm) without clinical signs of systemic spread (N0M0) were submitted to sentinel node biopsy between 1996 and 2000. Preoperative lymphoscintigraphy was routinely performed in the last 184 patients. Intraoperative mapping with gamma probe was combined with the use of vital dye for identification of sentinel nodes in the last 113 patients.

Results

The SN detection rate was 95.6%, with significant differences depending on the site of dissection and the use of a gamma probe. The overall rate of micrometastases was 14.7%, but relevant differences were recorded between different subgroups of patients (T2, 5.1%; T3a, 19.6%; T3b, 29%).

Conclusions

Sentinel node biopsy requires a multidisciplinary approach (surgery, pathology and nuclear medicine) for reliable results. The association of vital dye and intraoperative gamma probe for sentinel node harvesting has made the procedure more effective, less time-consuming and less invasive. Failures may be due not only to surgical mistakes, but also to improper nuclear medicine procedures or inaccurate histological evaluation of SNs. Methods for histological examination of the SN are still debated and not standardized but promising results have recently been obtained with molecular oncology techniques (RT-PCR).

Comparing multiple correspondence and principal component analyses with biomechanical signals. Example with turning the steering wheel

The purpose of this article is to compare Principal Component Analysis (PCA) and a much less used method, i.e. MCA (Multiple Correspondence Analysis) with data being first changed into membership values to fuzzy space windows. For such a comparison, data from an experimental study about turning the steering wheel is used. In a didactic perspective, this article only considers one multidimensional signal with 5 components: 3 linked to the steering wheel angle and hand positions and 2 to hand effort variables. A discussion weighs out the pros and the cons of both methods with criteria such as the possibility to show complex relational phenomena, the analysis/computing time or the information loss inherent to the averaging stage (in the perspective to analyze several hundreds of large multidimensional signals).

Collection of normative data for spatial and temporal gait parameters in a sample of French children aged between 6 and 12

OBJECTIVE

Normative data on gait is essential for clinical practice - especially in children whose gait pattern changes over time. Sets of normative gait data in healthy children vary significantly from one country to another. We decided to generate a specific reference database of gait parameters for French children.

METHOD

Three hundred and eighty-two children (228 boys and 154 girls, aged between 6 and 12) were asked to walk as naturally as possible and at a self-selected speed on a GAITRite track. Velocity, step count, cadence, step time, step length, cycle time, stride length, base width, swing time, stance time, single support time and double support time were recorded. Parameters were analyzed by age group, height group and BMI.

RESULTS

Velocity, step and stride length increased regularly with advancing age and height. Cadence decreased with height. All temporal parameters (except for double support) differed significantly (P<0.05) when comparing the 6-year-old group or the 7-year-old group with the 9-year-old group and older groups. A small number of temporal parameters (cadence, step time, cycle time and stance time) differed significantly when comparing 7-year-olds and 8-year-olds. Temporal parameters appeared rise in proportion height from 110 cm to 130 cm and then reached a plateau. Overweight was associated with a longer stance time and more double support.

CONCLUSION

The gait pattern in French children aged between 6 and 12 differs from those recorded elsewhere in the world; although gait parameters appear to change in much the same way with age worldwide, our values (even when normalized) are different. Our local database should be of value in French studies of childhood gait disorders. Given that gait patterns do not appear to mature by the age of 12, it would be valuable to study gait patterns in a population of teenagers.

Involving patients who attempt suicide in suicide prevention: a focus groups study

The aim of this study is to gain insight into the individual experiences of patients who attempt suicide in order to better understand the reasons for and emotions behind a suicide attempt, thus also gaining insight, through the patients' own input, into the risk and protective factors which might influence possible repeat attempts and the attitude towards the assistance they receive. Two focus groups were conducted involving 17 participants, all hospitalized at the time of research for attempting suicide. The patients proved themselves competent, even expert in indicating reasons for, risk factors of and prevention strategies for suicide. The main findings suggest that the relational factor represents a key point both as a trigger for the suicide attempt and for promoting the communication of the intent or for preventing a repeat suicide attempt, as interpersonal relationships and an empathic environment were, in essence, what was perceived as therapeutic and protective and enabled the expression of thoughts and self-understanding. Accordingly psychotherapy, non-specific relationship 'monitoring' after discharge and tutored self-help groups have been suggested. Feasibility and implementing methods as well as the role of the nurse for such interventions were discussed.

Is the time for suicide a random choice among young adults? An Italian study

Introduction

Every year between 100’000 and 200’000 young people die by suicide and possibly 40 times as many attempt it [1]. Several studies analyze the seasonality of suicide in the general population, but few of them investigate it among young adults.

Objectives

We look for a seasonal pattern in suicidal behaviors performed by young adults and evaluate the lethality of their behaviors.

Aims

We test the hypothesis that(a)

Methods

Analyses are based on data for 3614 cases of suicidal behaviours performed by individuals aged between 18 to 24 occurring between 2001 and 2008, provided by the Italian Institute for Statistical Analysis (ISTAT). Variables included in the analysis were gender, lethality of the act and season.

Results

ANOVA shows a significant association between months and number of suicides with a significant difference between the first and the second semester. Peaks were found in January, March and May. Males have a significantly greater regularity of the peaks than females (Mann-Whitney U- Test p < 0,001). Females have a rapport between completed and attempted suicides of 0.14, while among males it is of 0.72.

Conclusions

Clinical implications of these findings should be considered with the aim of developing more effective preventative strategies targeted to this age group.

EOS orthopaedic imaging system to study patellofemoral kinematics: assessment of uncertainty

BACKGROUND

Accurate knowledge of knee joint kinematics, especially patellofemoral joint kinematics,is essential for prosthetic evaluation so as to further improve total knee arthroplasty performances. Improving the evaluation of the functioning of the extensor apparatus appears,in this respect, particularly important in this optimization effort.

OBJECTIVES

The aim of this study was to propose a new experimental setup for the analysis of knee joint kinematics and to validate its relevance in terms of accuracy and uncertainty.The technique developed herein combines 3D reconstruction imaging with the use of a motion capture system.

MATERIAL AND METHODS

Eight pairs of fresh-frozen cadaver specimens with no evidence of previous knee surgery were studied using a new test rig where the femur remains fixed and the tibia is free to rotate. The flexion-extension cycles were executed using computer-controlled traction of the quadriceps tendon combined with an antagonist force applied to the distal part of the tibia. Knee joint kinematics were tracked using an optoelectronic motion capture system after a preliminary stage of data acquisition of bone geometry and markers position. This stage was carried out using a new digital stereophotogrammetric system, EOS, combined with specific 3D reconstruction software that also determined the coordinate system used in the kinematic analysis. The resulting uncertainty was assessed as was its impact on the estimated kinematics.

RESULTS

Test results on eight knees validated the setup designed for the analysis of knee joint kinematics during the flexion-extension cycle. More specifically, the statistical results show that measurement uncertainty for rotations and translations remains below 0.4 and 1.8 mm,respectively, for the tibia and 0.4 and 1.2 mm for the patella (+/- 2 S.D. for all four measurements).

DISCUSSION

The combination of 3D imaging and motion capture enables the proposed method to track the real-time motion of any bone segment during knee flexion-extension cycle. In particular,the new test rig introduced in this paper allows in vitro measurements of the patello femoral and tibiofemoral kinematics with a good level of accuracy. Moreover, this personalized experimental analysis can provide a more objective approach to the evaluation of knee implants as well as the validation of the finite-elements-based models of the patellofemoral joint.

Lifetime co-morbidity with different subtypes of eating disorders in 148 females with bipolar disorders

OBJECTIVES

To evaluate the impact of Eating Disorders (EDs) lifetime co-morbidity among female with Bipolar Disorders (BDs) and to compare clinical and cognitive features among EDs subgroups.

METHOD

A hundred and forty eight women with a lifetime history of Diagnostic and Statistical Manual, Fourth Edition (DSM-IV)-defined Bipolar-I, Bipolar-II and/or Cyclothymia, were consecutively enrolled to determinate the prevalence of co-morbid DSM-IV-defined Anorexia Nervosa [AN], Bulimia Nervosa [BN] or Binge Eating Disorder [BED]. Measures included the Structured Clinical Interview for the DSM-IV Axis I Disorders (SCID-I), the Clinical Global Impression (CGI) rating scale, the Eating Disorder Examination Questionnaire (EDE-Q) and BMI record.

RESULTS

Forty six patients (31%) reported lifetime history of at least one ED: AN was the most common ED (n=23, 15.5%), followed by BED (n=21, 14.2%), and BN (n=8, 5.4%); 6 patients (4.1%) reported multiple lifetime EDs. As expected, BMI was highest in BED patients and lowest in those with AN. Clinical characteristics were similar in the 3 groups, while rapid cycling and co-morbid drug abuse were more common in BED compared to AN or No-ED group. As expected cognitive eating symptoms assessed by the EDE-Q were all more represented in AN than in No-ED patients. AN and BED only differed in restricting behavior and weight concerns.

CONCLUSIONS

Our results prompt for the recognition of co-morbid EDs among bipolar patients, indicating that BED, along with other EDs, may influence in different ways both clinical characteristics and course of the illness. Further perspective studies are necessary to better define the relationships between different EDs and Bipolar Spectrum disorders.

Identification of cells secreting a thymostimulin-like substance and examination of some histoenzymatic pathways in aging avian primary lymphatic organs: II. Bursa of Fabricius

The Bursa of Fabricius of 15 day, 1-, 3-, and 6 month-old adult chickens (White Leghorn strain) were studied by histological and histochemical staining, histoenzymatic reactions (LDH, SDH, a-GPDH, NAD, NADPH, Ca++-dependent ATP-ase, pH 8.5) and by anti-thymostimulin immunoreaction. Positive reactions for mucopolysaccharides and enzymatic activities were located in the epithelia of the follicles, i.e. in follicleassociated- epithelium (FAE), inter-follicle-epithelium (IFE) and in different epithelial compartments of cortical and medullary zones. Positive reaction for thymostimulin-like (TSlike) substance was restricted to FAE cells and weakly to the basal lamina of IFE. In 6-month-old chickens, the FAE cells disappeared; the phenomenon of bursal regression was evident, although not all the follicles were involved. In the few still normal follicles, the good reactivity to the enzymes tested suggests that residual physiological activity is still present, even if reduced.

Time-frequency analysis to detect bone fracture in impact biomechanics. Application to the thorax

Experimental testing is a major source of data to quantify the tolerance of the human body to impact and to develop protection strategies. Correlating the time of rib fractures with the kinematics of the occupant and the action of safety systems would provide valuable data for assessing safety systems and developing injury risk functions. However, methods for determining rib fractures timing are not yet fully developed. Time-history analysis of data from multiple strain gauges mounted directly to ribs is commonly used for this purpose, but this method is not very sensitive and the time and cost required to instrument the rib cage with more than 100 strain gauges is prohibitive for many applications. In this study a new approach based on time-scale analysis of signals obtained from piezoelectric transducers (PZT) is reported. A post-mortem human subject was instrumented with four PZT on ribs 3 and 7 bilaterally and exposed to lateral blunt impacts to the shoulder and the chest. The fractures were documented after each test, and a criterion was developed to process the PZT signals. The criterion consists in detecting in the PZT signal the onset of a high frequency transient generated by the fracture of a rib using the continuous wavelet transform. Two thresholds were successfully determined to detect fractures that occurred (1) on an instrumented rib, and (2) on the adjacent rib. Further development of this method should allow the detection of all rib fractures using only a few PZT.

Long-term outcome of a multicentre randomized clinical trial of stapled haemorrhoidopexy versus Milligan-Morgan haemorrhoidectomy

INTRODUCTION

Stapled haemorrhoidopexy is less painful than Milligan-Morgan haemorrhoidectomy, allowing an earlier return to working activities, but its long-term efficacy is not fully established. This study reports the long-term follow-up of a randomized clinical trial comparing the two techniques in 100 patients affected by third- and fourth-degree haemorrhoids.

METHODS

All patients were contacted and invited to attend the clinic to assess long-term functional outcome. The degree of continence and satisfaction were assessed by questionnaire. Anal manometry and anoscopy were performed.

RESULTS

Eighty patients were available after a median follow-up of 87 months. No statistically significant differences were found between the two groups in terms of incontinence, stenosis, pain, bleeding, residual skin tags or recurrent prolapse. A tendency towards a higher recurrence rate was reported in patients with fourth-degree haemorrhoids, irrespective of the technique used. No significant changes in anal manometric values were found after surgery in either group.

CONCLUSION

Both techniques are effective in the long term.

Hep27, a member of the short-chain dehydrogenase/reductase family, is an NADPH-dependent dicarbonyl reductase expressed in vascular endothelial tissue

Human Hep27 was originally isolated from growth-arrested HepG2 cells and identified as a member of the superfamily of short-chain dehydrogenases/reductases (SDR). Its substrate specificity has not been determined, but a cross-species comparison suggests that it occurs in widely divergent species, such as human, Cenorhabditis elegans, Drosophila and Arabidopsis thaliana. In this study, Hep27 was expressed as a His(6) fusion protein, and subjected to a substrate screen, using a compound library of SDR substrates, comprising steroids, retinoids, sugars and carbonyl compounds. Whereas no steroid dehydrogenase or retinoid activity was detected, it was found that Hep27 catalyzed the NADPH-dependent reduction of dicarbonyl compounds, like 3,4-hexanedione and 1-phenyl-1,2-propanedione with similar turnover numbers as DCXR (a mitochondrial dicarbonyl reductase/xylulose reductase). In contrast, Hep27 does not convert sugar substrates like xylulose or threose. Based on its substrate specificity and expression in endothelial tissues, it is suggested that Hep27 functions as a dicarbonyl reductase in enzymatic inactivation of reactive carbonyls, involved in covalent modification of cellular components.

Identification of cells secreting a thymostimulin-like substance and examination of some histoenzymatic pathways in aging avian primary lymphatic organs: II. Bursa of Fabricius

The Bursa of Fabricius of 15 day, 1-, 3-, and 6 month-old adult chickens (White Leghorn strain) were studied by histological and histochemical staining, histoenzymatic reactions (LDH, SDH, a-GPDH, NAD, NADPH, Ca++-dependent ATP-ase, pH 8.5) and by anti-thymostimulin immunoreaction. Positive reactions for mucopolysaccharides and enzymatic activities were located in the epithelia of the follicles, i.e. in follicle-associated-epithelium (FAE), inter-follicle-epithelium (IFE) and in different epithelial compartments of cortical and medullary zones. Positive reaction for thymostimulin-like (TS-like) substance was restricted to FAE cells and weakly to the basal lamina of IFE. In 6-month-old chickens, the FAE cells disappeared; the phenomenon of bursal regression was evident, although not all the follicles were involved. In the few still normal follicles, the good reactivity to the enzymes tested suggests that residual physiological activity is still present, even if reduced.

[Sentinel node biopsy for malignant melanoma. Technical details and clinical results on 390 patients]

BACKGROUND

The purpose of this paper is to present personal experience with sentinel node biopsy for the treatment of malignant melanoma. Technical details influencing the efficacy of the procedure are presented and the clinical, therapeutic and prognostic advantages of this technique discussed.

METHODS

A total of 390 consecutive patients with primary skin melanoma (T2-3,N0,M0) underwent sentinel node biopsy between March 1996 and May 2001. All patients underwent previous excisional biopsy of the primary lesion and clinical and radiographic examination to exclude lymphatic or systemic macroscopic spreading of the disease. Preoperative lymphoscintigraphy (99mTc nanocoll) was routinely performed in the last 315 patients. Intraoperative detection of the sentinel nodes was performed by perilesional, intradermical, injection of blue dye associated with a g probe (Neoprobe(R) 2000) in the last 315 patients. Sentinel nodes, serially sectioned, were all Haematoxylin-Eosin and immunohistochemically stained. All patients positive for micro-metastasis underwent radical lymphadenectomy. Comparative analysis between the incidence of metastasis in sentinel and non-sentinel nodes, according to the clinical stage of the disease, was done.

RESULTS

The overall detection rate of sentinel nodes was 97.4%. Relevant differences were found according to the site of dissection and the use of a g probe. The g-probe makes the procedure more effective, less invasive and less expensive. Timing and accuracy of the preoperative lymphoscintigraphy is a basic step of the procedure. The overall incidence of positive sentinel nodes was 14.7% with differences correlated with thickness of primary lesion (0.75-1.5 mm: 5,8%; 1.5-3 mm:18%; 3-4 mm: 24.6%). Metastasis in other non-sentinel nodes was found only with primary tumour thickness exceeding 2 mm.

CONCLUSIONS

Sentinel node biopsy is a procedure requiring a multidisciplinary approach (surgery, nuclear medicine and pathology). A specific learning phase (>30 patients) is recommended to obtain reliable results.

Evaluation of myocardial involvement in systemic lupus erythematosus by signal-averaged electrocardiography and echocardiography

OBJECTIVE

The myocardial involvement in systemic lupus erythematosus (SLE) patients, frequently found at autopsy or at endomyocardial biopsy, is less easily detected clinically. The myocardial lesions are characterized by an increase in interstitial connective tissue and myocardial scarring. Signal-averaged electrocardiography (ECG-SA) is currently used for recording ventricular late potentials which are the expression of slowed and disorganized conduction through zones of myocardial scarring. M-mode, two-dimensional and Doppler echocardiography (ECHO) represent relatively simple methods for evaluating the left ventricular function. This study was aimed to evaluate by ECG-SA and ECHO the myocardial involvement of SLE patients without clinical and electrocardiographic evidence of cardiac disease.

METHODS AND RESULTS

Twenty outpatients with SLE were studied and compared with 18 normal controls. Late potentials were recorded in 20% of SLE patients and in 5.5% of controls. A significant increase of abnormal left ventricular diastolic filling was found in the SLE patients, characterized by reduced E/A (p = 0.018), a lower deceleration rate of early diastolic flow velocity (p = 0.048) and a prolonged isovolumic relaxation time (p = 0.001). SLE patients had diastolic dysfunction of various degrees although the depolarization abnormalities detected by ECG-SA were found only in a few subjects.

CONCLUSIONS

The depolarization abnormalities, revealed by ECG-SA, probably reflect a longer extent of myocardial fibrosis in SLE patients with ECHO evidence of abnormal left ventricular filling. The simultaneous occurrence of ECHO and ECG-SA alterations could be a marker of subclinical myocardial involvement.

Immunologic evidence of no harmful effect of oats in celiac disease

BACKGROUND

It was recently shown that antiendomysial antibodies (EMAs), which are highly sensitive and specific for celiac disease, are produced by intestinal mucosa. Furthermore, EMAs were detected previously in supernatant fluid from cultured duodenal mucosa specimens collected from untreated celiac disease patients and in culture media of biopsy specimens collected from treated celiac disease patients after an in vitro challenge with gliadin. Moreover, it was recently shown in vivo that oats are not toxic to celiac disease patients, suggesting the safety of oats in a gluten free-diet.

OBJECTIVE

The objective was to better define the controversial role of oats in celiac disease to determine whether oats can be safely included in a gluten-free diet.

DESIGN

We used an in vitro model to test whether oats induce EMA production in supernatant fluid from cultured duodenal mucosa specimens collected from 13 treated celiac disease patients. The biopsy specimens were cultured with and without peptic-tryptic digest (PT) of gliadin and avenin (from oats) and in medium alone. Samples from 5 of the 13 patients were cultured with the C fraction of PT-avenin. Indirect immunofluorescence was used to detect EMAs.

RESULTS

EMAs were detected in specimens from all 13 patients after the challenge with gliadin but not after culture in medium alone. By contrast, no EMAs were detected in any of the specimens cultured with PT-avenin and its C fraction.

CONCLUSIONS

Because the in vitro challenge with PT-avenin and its C fraction did not induce EMA production in treated celiac disease patients, it appears that oats have no harmful effect on celiac disease. Therefore, oats can be safely included in a gluten-free diet.

Day surgery for mucosal-hemorrhoidal prolapse using a circular stapler and modified regional anesthesia

PURPOSE

In 1993, prolapse reduction using the circular stapler for the treatment of hemorrhoidal disease was proposed. The procedure is characterized by minimal postoperative pain. In this study we evaluated the above technique using regional anesthesia to identify the advantages and feasibility of stapled hemorrhoidectomy, with special focus on the efficacy of same-day discharge.

METHODS

From December 1997 to November 1999, we performed 70 consecutive reduction corrections of mucosal hemorrhoidal prolapse using the circular stapler with regional anesthesia (a technical modification of Marti's posterior perineal block). Our series included 41 males and 29 females with a mean age of 43.4 (range, 25-74) years. Three patients were affected by second-degree hemorrhoids and 67 by third-degree hemorrhoids.

RESULTS

Sixty-two patients were discharged three hours after the operation in good general condition and without pain, whereas eight patients were discharged the day after for early complications, consisting of two cases of early bleeding, three cases of urinary retention, and three cases of persistent severe pain requiring prolonged medical treatment.

CONCLUSION

Our study shows that, in selected cases, it is possible to perform day surgery for patients with hemorrhoidal disease using a circular stapler device when combined with regional anesthesia.

Prospective randomized multicentre trial comparing stapled with open haemorrhoidectomy

BACKGROUND

The aim of this study was to compare the results of conventional open haemorrhoidectomy as currently practised in Italy (group 1) with stapled haemorrhoidectomy using a 33-mm circular stapling device (group 2).

METHODS

One hundred patients with symptomatic third- and fourth-degree haemorrhoids were enrolled by five hospitals. Patients were allocated to the two groups according to a centralized randomization scheme featuring five permutated blocks of 20. Preoperative clinical examination and anorectal manometry demonstrated no features of anal incontinence. Patients had a clinical and manometric re-evaluation after operation and were asked to complete a clinical diary. After a median of 16 (range 8-19) months patients were administered a standardized questionnaire by telephone.

RESULTS

Postoperative bleeding requiring haemostatic procedures occurred in three patients in each group. Patients in group 1 complained of moderate pain for a median of 5.3 (range 0-19) days compared with 3.1 (range 0-10) days in group 2 (P = 0.01), while severe pain was present for 2.3 (range 0-24) days in group 1 but only for 1 (range 0-14) day in group 2 (P = 0.03). The median hospital stay was 2 days in group 1 compared with 1 day in group 2 (P = 0.01). In the early days after operation, patients in group 2 had greater difficulty in maintaining normal continence to liquid stools (P = 0.01), but after 30 days the continence score was better in group 2 (P = 0.04).

CONCLUSION

Stapled haemorrhoidectomy is as effective as conventional haemorrhoidectomy. Reduced postoperative pain, shorter hospital stay and a trend toward earlier return to work suggest short-term advantages for the stapled technique.

Identification of a new coeliac disease subgroup: antiendomysial and anti-transglutaminase antibodies of IgG class in the absence of selective IgA deficiency

OBJECTIVE

The aim of the present study was to increase the sensitivity of the antiendomysial antibody (EMA) test by evaluating also EMAs of IgG1 isotype.

DESIGN AND SUBJECTS

Over the last 2 years, serum EMAs IgA and IgG1 were determined in 1399 patients, referred to our gastrointestinal unit due to clinical suspicion of malabsorption. Serum anti-tissue transglutaminase (tTG) antibodies IgA and IgG, as well as total IgA levels, were also investigated. Furthermore, EMAs IgA and IgG1 were evaluated in biopsy culture supernatants. Biopsy specimens were also admitted to histological and immunohistochemical evaluation. Twenty-six patients with gastroenterological disease other than coeliac disease (CD) were used as a disease control group. Ninety-nine blood donors were used as a healthy control group.

RESULTS

Diagnosis of CD was based on histological findings in the 110/1399 patients showing EMA IgA positivity, and in a further 56/1399 patients presenting both EMA IgA and IgG1 positivity in sera as well as in culture supernatants. Of the remaining 1233 EMA IgA-negative patients, 60 showed only EMA IgG1 positivity both in sera and in culture supernatants. It is noteworthy that anti-tissue transglutaminase antibodies IgG (anti-tTG) were positive in all 60 EMA IgG1-positive patients as well. By contrast, a selective IgA deficiency was found in only 11 out of the 60 EMA IgG1-positive patients. Villous height/crypt depth ratio was < 3:1 in 38 of the 60 EMA IgG1-positive patients (63.3%), whilst overexpression of ICAM-1 and CD25 was observed in all these patients.

CONCLUSIONS

In this study, we observed a group of CD patients who were EMA IgG1-positive even in the absence of EMA IgA positivity and IgA deficiency. The diagnosis was based on the finding of the gluten-dependent clinical and histological features typical of CD. Data emerging from the present investigation thus suggest that the prevalence of CD should be reassessed and that the determination of EMA IgG1 could offer a new tool in the diagnostic armamentarium of CD.

Suture materials and other factors associated with tissue reactivity, infection, and wound dehiscence among plastic surgery outpatients

The most common complications in plastic surgery are tissue reactivity, infections, and wound dehiscence. In the literature, there are only a few studies with sample sizes large enough and methods of statistical analysis appropriate for evaluating the role of suture materials in inducing such complications. In the 1000 plastic surgery outpatients in this study, the association of different suture materials, individual patient characteristics, surgeon skill, and wound site and length with postoperative wound complications (i.e., tissue reactivity, infection rate, and wound dehiscence) were investigated. No substantial differences were found between the different suture materials and suturing techniques. A moderate increase in the risk of tissue reactivity for silk and polyglactin 910 and a protective effect of thinner internal sutures were observed. In multivariate analysis, such differences were not statistically significant. Male sex [odds ratio (OR), 1.7; 95 percent confidence interval (CI), 1.06 to 2.72] and older age (OR, 2.34; 95 percent CI, 1.36 to 4.05) were found to be the most important risk factors for tissue reactivity and infection rate (male sex: OR, 5.1; 95 percent CI, 1.7 to 15.9; older age: OR, 5.6; 95 percent CI, 1.9 to 16), whereas younger age was associated with an increased risk of dehiscence (OR, 3.06; 95 percent CI, 1.41 to 6.65). Wounds on the lower limbs showed a lower risk of tissue reactivity and wounds on the back a higher risk of dehiscence. Wound length was associated with the risk of tissue reactivity in one-layer sutures (OR, 2.92; 95 percent CI, 1.51 to 5.65). An increased risk of both tissue reactivity (OR, 1.53; 95 percent CI, 1.03 to 2.27) and dehiscence (OR, 2.44; 95 percent CI, 1.1 to 5.43) was observed for operations performed by less-experienced surgeons. Rather than factors related to suture materials and different surgical techniques, and with the exception of surgeon experience, general characteristics of the patients (i.e., sex and age) and of the wounds (i.e., length and site) seemed to be primarily responsible for local wound complications.

[Optimization of lymphoscintigraphy in sentinel node biopsy in the staging of malignant melanoma]

PURPOSE

To optimize the lymphoscintigraphic procedure in the staging of malignant cutaneous melanoma.

MATERIAL AND METHODS

Fifty-five patients (21 men and 34 women) were enrolled. Breslow thickness of the lesions ranged 0.75-1 mm (Clark III-IV) to 1-4 mm. Lymphoscintigraphy was performed with a large-view gamma camera equipped with a low-energy general purpose collimator, two weeks after melanoma excision. A single perilesional dose of 30-50 MBq nanocoll-Tc99m (volume 0.2-0.3 mL) was injected 18 hours before surgery (6 hours in head localizations). After injection a gentle local massage was applied. A planar static scintigraphy (matrix 512 x 512, pre-set time 5 min) in anterior and/or oblique view(s) was obtained 5-10 min after radiotracer injection. The skin projection of the first node was stained with an external radioactive marker. Fifteen minutes before surgery a blue-vital dye was injected around the lesion. A radioguided biopsy of the sentinel node was performed.

RESULTS

The site of the sentinel node was typical in 80% of patients. Two or three nodes were identified in 20% of patients. An unexpected node site was detected in 9% of patients. The total rate of micrometastasis to the sentinel node was 14.7% but significant differences were observed relative to the melanoma thickness.

CONCLUSIONS

Preoperative scintigraphy increases the accuracy of sentinel node identification in unusual lymphatic drainage pathways, in unexpected sites and in fast lymphatic drainage. Radioguided biopsy reduces surgical time, requires only local anesthesia and permits shorter hospitalization.

Celiac disease diagnosis in misdiagnosed children

Antiendomysial antibodies (EMA) are today considered the most sensitive and specific serological marker of celiac disease (CD). The aim of the present study was to assess the occurrence of EMA of IgG isotype in EMA IgA negative children with clinical suspicion of malabsorption and their relationship with CD. Serum EMA IgG1 determination was performed on 30 EMA IgA negative children with clinical suspicion of CD. Total serum IgA levels were further investigated. Sixty children with gastroenterological diseases other than CD were used as control disease patients and 63 healthy children were evaluated as the control group. Eighteen out of 30 children in the study showed EMA IgG1 positivity in sera and a villous height/crypt depth ratio <3:1 as index of intestinal atrophy. It is noticeable that a selective IgA deficiency was present in only 9 of 18 EMA IgG1 positive children. In addition, clinical symptoms, EMA IgG1, and mucosal atrophy disappeared after 8-10 mo on a gluten-free diet. Neither EMA IgA nor EMA IgG1 were detected in the children in the control groups. The other 12 children in study group showed no histologic abnormalities and were EMA IgG1 negative. In this study, we reveal a group of EMA IgG1 CD children without IgA deficiency. The diagnosis was based on the presence of gluten-dependent typical serological and histologic features of CD. Our data suggest that EMA IgG1 determination could be a new tool in the diagnostic workup of CD, useful in avoiding possible misdiagnosis.

Hemorrhoidectomy with posterior perineal block: experience with 400 cases

PURPOSE

The aim of this study was to evaluate the advantages and feasibility of hemorrhoidectomy using regional anesthesia (posterior perineal block).

METHODS

From March 1994 to December 1998 we performed 400 hemorrhoidectomies with regional anesthesia in an overnight-stay regimen in our department (Colo-Rectal Unit). Posterior perineal block involves anesthesia of the deep plains (infiltration of the inferior hemorrhoidal nerves, the posterior branch of the internal pudendal nerves, and the anococcygeal nerves) and anesthesia of the superficial plains (block of the inferior gluteal nerves and of perineal branches of minor nerves from the sacral plexus).

RESULTS

Posterior perineal block was always effective; optimal to satisfactory intraoperative analgesia was obtained in 379 patients (95.2 percent), whereas in 17 cases (4.2 percent) intravenous analgesic drugs were administered. No conversion to general anesthesia was needed. Urinary retention was 7.8 percent. In our study most of patients (70 percent) reported no pain at all for five to ten hours. Ninety-two percent of patients were discharged in the first 24 hours.

CONCLUSIONS

Posterior perineal block allows the surgeon to perform radical hemorrhoidectomies in an overnight-stay regimen with safe and effective intraoperative and postoperative analgesia, sphincter relaxation, and low incidence of urinary retention. Experience of the surgeon combined with careful surgical handling are of great importance for success in this technique.