Differential gene expression analysis pipelines and bioinformatic tools for the identification of specific biomarkers: A review

In recent years, the role of bioinformatics and computational biology together with omics techniques and transcriptomics has gained tremendous importance in biomedicine and healthcare, particularly for the identification of biomarkers for precision medicine and drug discovery. Differential gene expression (DGE) analysis is one of the most used techniques for RNA-sequencing (RNA-seq) data analysis. This tool, which is typically used in various RNA-seq data processing applications, allows the identification of differentially expressed genes across two or more sample sets. Functional enrichment analyses can then be performed to annotate and contextualize the resulting gene lists. These studies provide valuable information about disease-causing biological processes and can help in identifying molecular targets for novel therapies. This review focuses on differential gene expression (DGE) analysis pipelines and bioinformatic techniques commonly used to identify specific biomarkers and discuss the advantages and disadvantages of these techniques.

Health system assessment for access to care after injury in low- or middle-income countries: A mixed methods study from Northern Malawi

BACKGROUND

Injuries represent a vast and relatively neglected burden of disease affecting low- and middle-income countries (LMICs). While many health systems underperform in treating injured patients, most assessments have not considered the whole system. We integrated findings from 9 methods using a 3 delays approach (delays in seeking, reaching, or receiving care) to prioritise important trauma care health system barriers in Karonga, Northern Malawi, and exemplify a holistic health system assessment approach applicable in comparable settings.

METHODS AND FINDINGS

To provide multiple perspectives on each conceptual delay and include data from community-based and facility-based sources, we used 9 methods to examine the injury care health system. The methods were (1) household survey; (2) verbal autopsy analysis; (3) community focus group discussions (FGDs); (4) community photovoice; (5) facility care-pathway process mapping and elucidation of barriers following injury; (6) facility healthcare worker survey; (7) facility assessment survey; (8) clinical vignettes for care process quality assessment of facility-based healthcare workers; and (9) geographic information system (GIS) analysis. Empirical data collection took place in Karonga, Northern Malawi, between July 2019 and February 2020. We used a convergent parallel study design concurrently conducting all data collection before subsequently integrating results for interpretation. For each delay, a matrix was created to juxtapose method-specific data relevant to each barrier identified as driving delays to injury care. Using a consensus approach, we graded the evidence from each method as to whether an identified barrier was important within the health system. We identified 26 barriers to access timely quality injury care evidenced by at least 3 of the 9 study methods. There were 10 barriers at delay 1, 6 at delay 2, and 10 at delay 3. We found that the barriers "cost," "transport," and "physical resources" had the most methods providing strong evidence they were important health system barriers within delays 1 (seeking care), 2 (reaching care), and 3 (receiving care), respectively. Facility process mapping provided evidence for the greatest number of barriers-25 of 26 within the integrated analysis. There were some barriers with notable divergent findings between the community- and facility-based methods, as well as among different community- and facility-based methods, which are discussed. The main limitation of our study is that the framework for grading evidence strength for important health system barriers across the 9 studies was done by author-derived consensus; other researchers might have created a different framework.

CONCLUSIONS

By integrating 9 different methods, including qualitative, quantitative, community-, patient-, and healthcare worker-derived data sources, we gained a rich insight into the functioning of this health system's ability to provide injury care. This approach allowed more holistic appraisal of this health system's issues by establishing convergence of evidence across the diverse methods used that the barriers of cost, transport, and physical resources were the most important health system barriers driving delays to seeking, reaching, and receiving injury care, respectively. This offers direction and confidence, over and above that derived from single methodology studies, for prioritising barriers to address through health service development and policy.

Ultra-rare RTEL1 gene variants associate with acute severity of COVID-19 and evolution to pulmonary fibrosis as a specific long COVID disorder

BACKGROUND

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a novel coronavirus that caused an ongoing pandemic of a pathology termed Coronavirus Disease 19 (COVID-19). Several studies reported that both COVID-19 and RTEL1 variants are associated with shorter telomere length, but a direct association between the two is not generally acknowledged. Here we demonstrate that up to 8.6% of severe COVID-19 patients bear RTEL1 ultra-rare variants, and show how this subgroup can be recognized.

METHODS

A cohort of 2246 SARS-CoV-2-positive subjects, collected within the GEN-COVID Multicenter study, was used in this work. Whole exome sequencing analysis was performed using the NovaSeq6000 System, and machine learning methods were used for candidate gene selection of severity. A nested study, comparing severely affected patients bearing or not variants in the selected gene, was used for the characterisation of specific clinical features connected to variants in both acute and post-acute phases.

RESULTS

Our GEN-COVID cohort revealed a total of 151 patients carrying at least one RTEL1 ultra-rare variant, which was selected as a specific acute severity feature. From a clinical point of view, these patients showed higher liver function indices, as well as increased CRP and inflammatory markers, such as IL-6. Moreover, compared to control subjects, they present autoimmune disorders more frequently. Finally, their decreased diffusion lung capacity for carbon monoxide after six months of COVID-19 suggests that RTEL1 variants can contribute to the development of SARS-CoV-2-elicited lung fibrosis.

CONCLUSION

RTEL1 ultra-rare variants can be considered as a predictive marker of COVID-19 severity, as well as a marker of pathological evolution in pulmonary fibrosis in the post-COVID phase. This notion can be used for a rapid screening in hospitalized infected people, for vaccine prioritization, and appropriate follow-up assessment for subjects at risk. Trial Registration NCT04549831 ( www.

CLINICALTRIAL

org ).

Heterozygosity for neuronal ceroid lipofuscinosis predisposes to bipolar disorder

OBJECTIVE

Bipolar disorder is a heritable chronic mental disorder that causes psychosocial impairment through depressive/manic episodes. Familial transmission of bipolar disorder does not follow simple Mendelian patterns of inheritance. The aim of this study was to describe a large family with 12 members affected by bipolar disorder. Whole-exome sequencing was performed for eight members, three of whom were diagnosed with bipolar disorder, and another reported as "borderline."

METHODS

Whole-exome sequencing data allowed us to select variants that the affected members had in common, including and excluding the "borderline" individual with moderate anxiety and obsessive-compulsive traits.

RESULTS

The results favored designating certain genes as predispositional to bipolar disorder: a heterozygous missense variant in CLN6 resulted in a "borderline" phenotype that, if combined with a heterozygous missense variant in ZNF92, is responsible for the more severe bipolar disorder phenotype. Both rare missense changes are predicted to disrupt protein function.

CONCLUSIONS

Loss of both alleles in CLN6 causes neuronal ceroid lipofuscinosis, a severe progressive childhood neurological disorder. Our results indicate that heterozygous CLN6 carriers, previously reported as healthy, may be susceptible to bipolar disorder later in life if associated with additional variants in ZNF92.

Artificial Intelligence Predictive Models of Response to Cytotoxic Chemotherapy Alone or Combined to Targeted Therapy for Metastatic Colorectal Cancer Patients: A Systematic Review and Meta-Analysis

Tailored treatments for metastatic colorectal cancer (mCRC) have not yet completely evolved due to the variety in response to drugs. Therefore, artificial intelligence has been recently used to develop prognostic and predictive models of treatment response (either activity/efficacy or toxicity) to aid in clinical decision making. In this systematic review, we have examined the ability of learning methods to predict response to chemotherapy alone or combined with targeted therapy in mCRC patients by targeting specific narrative publications in Medline up to April 2022 to identify appropriate original scientific articles. After the literature search, 26 original articles met inclusion and exclusion criteria and were included in the study. Our results show that all investigations conducted on this field have provided generally promising results in predicting the response to therapy or toxic side-effects. By a meta-analytic approach we found that the overall weighted means of the area under the receiver operating characteristic (ROC) curve (AUC) were 0.90, 95% C.I. 0.80-0.95 and 0.83, 95% C.I. 0.74-0.89 in training and validation sets, respectively, indicating a good classification performance in discriminating response vs. non-response. The calculation of overall HR indicates that learning models have strong ability to predict improved survival. Lastly, the delta-radiomics and the 74 gene signatures were able to discriminate response vs. non-response by correctly identifying up to 99% of mCRC patients who were responders and up to 100% of patients who were non-responders. Specifically, when we evaluated the predictive models with tests reaching 80% sensitivity (SE) and 90% specificity (SP), the delta radiomics showed an SE of 99% and an SP of 94% in the training set and an SE of 85% and SP of 92 in the test set, whereas for the 74 gene signatures the SE was 97.6% and the SP 100% in the training set.

In vitro effects of concentrated growth factors (CGF) on human SH-SY5Y neuronal cells

OBJECTIVE

The aim of this study was to test the in vitro differentiation effects of concentrated growth factors (CGF), a platelet rich preparation, using SH-SY5Y cells, derived from human neuroblastoma.

MATERIALS AND METHODS

SH-SY5Y cells were cultured in presence of CGF or retinoic acid (RA). After 72 h of treatment, different parameters were investigated: cell proliferation by an automated cell counter; cell viability by thiazolyl blue tetrazolium bromide (MTT) assay; cell differentiation markers, i.e., neuronal nuclear antigen (NeuN), synaptophysin (SYP) and β3-tubulin, by immunocytochemistry and Western blotting techniques; release of nerve growth factor (NGF) and brain-derived growth factor (BDNF) by enzyme-linked immunosorbent assay (ELISA) and neurite outgrowth by a dedicated image software.

RESULTS

In presence of CGF, the cell proliferation rate and viability decreased, as expected for differentiated SH-SY5Y cells. On the contrary, the cellular differentiation markers increased their expression together with the release of growth factors. Moreover, the neurite outgrowth was improved.

CONCLUSIONS

The data suggest that CGF treatment positively affects the cell differentiation, regulating the expression of neuronal markers, the release of growth factors and the neurite length. Taken together these results seem to be promising in the development of new approaches for neural regeneration.

Stabilisation of the Trapezio-Metacarpal Joint

A new technique of trapezio-metacarpal stabilisation is described which uses the abductor pollicis longus tendon passed through the bases of the first and second metacarpals to fasten the base of the thumb. A biomechanical rationale is presented, as well as the surgical technique and 12 results at follow-up one to six years later.

Calcium sulfate stimulates pulp stem cells towards osteoblasts differentiation

Calcium sulfate (CaS) is a highly biocompatible material and enhances bone formation in vivo. However, how CaS alters osteoblast activity to promote bone formation is poorly understood. To study how CaS can induce osteoblast differentiation in mesenchymal stem cells, the expression levels of bone related genes and mesenchymal stem cells marker were compared in normal osteoblasts and dental pulp stem cells, using real time Reverse Transcription-Polymerase Chain Reaction. Gene differentially expressed between the two cells type were the trascriptional factor RUNX2, osteopontin (SPP1), COL1A1 (collagen type 1α1) and alkaline phosphatase (ALPL). The obtained results demonstrated that CaS strongly influences the behavior of DPSCs in vitro enhancing proliferation, differentiation and deposition of matrix.

Histomorphic-metric evaluation of an implant retrieved from human maxilla after 13 years

Fixture fracture is the most catastrophic failure of implant components because it usually causes the loss of the implant. Nevertheless, the osseointegrated fractured implants represent a very useful opportunity to study in humans the effects of loading to the peri-implant bone microstructure. The aim of the present study was to evaluate the interplay between microstructure and function of the bone around an implant retrieved from human maxilla after 13 years. There was 1 fractured Dental Implant Line (sand blasted surface from a patient placed in the anterior region of the maxillary bone (2.1) after a bone augmentation procedure, and it was processed for histology. The specimen was analyzed under the scanning electron microscope (SEM), the confocal scanning laser microscope (CSLM) and brightfield light microscope (LM) equipped with circularly polarized light (CPL). The BIC rate of the implant retrieved after 13 years was (mean ±SD) 68.7 ± 3.7. The crestal bone down the implant platform damage appeared to be under modeling process. The transverse collagen fiber orientation (CFO) (mean ±SD) under the lower flank of the threads was 20.4 ± 3.5 x 10(4) pixel while the longitudinal CFO was 19.8 ± 2.8 x 10(4) pixel (P>.05). In the inter-threads region the transverse CFO (mean ±SD) was 15.0 ± 4.0 x 10(4) pixel while the longitudinal CFO was 21.4 ± 3.0 x 10(4) pixel (P>.05). The osteocytes numbers (mean ±SD) was 130 ∓ 34. Under SEM with back scattered electrons (BSE) signal the peri-implant bone appears mainly lamellar and highly mature with several osteons organized in the implant inter-threads areas. The fracture of the implant was most probably correlated to a fatigue of the material mainly associated to a damage of the internal coil. Surprisingly, it was noted a lack of implant site-specific CFO of the bone extracellular matrix facing the threaded dental implant notwithstanding the high level of BIC rate.

Polylactide-Polyglycolide Resorbable Plates Stimulates Adipose Tissue-Derived Stem Cells towards Osteoblasts Differentiation

Polylactide, polyglycolide materials or devices have been utilized routinely during maxillofacial, craniofacial, and orthopaedic reconstructive surgical procedures.(1) These materials combine the benefits of rigid fixation with the advantages of biodegradation, avoiding the need for implant removal and minimizing the risk of other complications.(2) To study how polylactide, polyglycolide acids plates (PLPG plates) can induce osteoblast differentiation and proliferation in mesenchymal stem cells, the expression levels of bone related genes (RUNX2, SP7, ALPL, SPP1, COL1A1, COL3A1 and FOSL1) and mesenchymal stem cells marker (ENG) were measured in adipose derived stem cells (ADSCs) and normal osteoblast (NO) cultivated on PLPG plates after 15 and 30 days of treatment using real time Reverse Transcription-Polymerase Chain Reaction. Significantly differentially expressed genes among ADSCs and NO were SP7, ENG, FOSL1, RUNX, ALPL and SPP1 in the first 15 days of treatment and SP7, ENG FOSL1, COL3A1 COL1A1, SPP1 and ALPL after 30 days. The present study demonstrated that PLPG plates strongly influences the behavior of ADSCs in vitro by enhancing proliferation, differentiation and deposition of matrix.

Histomorphic-Metric Evaluation of an Immediately Loaded Implant Retrieved from Human Mandible after 2 Years

The aim of the present study was to evaluate the interplay between microstructure and function of the bone around an immediately loaded implant retrieved from human maxilla after 23 months due to fracture. A spiral implant of 3.3 mm x 15 mm was placed in a male 53 years old in the anterior region of the mandible bone (4.1) and it was processed for histology. The specimen was analyzed under the confocal scanning laser microscope (CSLM) and brightfield light microscope (LM) equipped with circularly polarized light (CPL). The BIC rate was 76.7± 4.9 (mean ±SD). Many cement lines indicates an high remodeling rate of the bone. The transverse collagen fiber orientation (CFO) (mean ±SD) under the lower flank of the thread near the tread tip was 55.2 ± 4.8 × 104 pixel while the longitudinal CFO was 45.8 ± 2.3 × 104 pixel (P<.05). In the inter-threads region the transverse CFO (mean ±SD) was 36.4 ± 2.4 × 104 pixel while the longitudinal CFO was 65.6 ± 6.5 × 104 pixel (P<.05). The osteocytes numbers (mean ±SD) was 205 ± 45 in the peri-implant bone and 144 ± 53 in the native bone (P=.007). After 2-years of loading the SLA spiral implant was well osseointegrated but still surrounded by woven bone. The osteocytes density was significantly higher in the peri-implant bone than in the native bone. The transverse collagen fibers were significantly associated with the lower flank of the implant threads, while the longitudinal collagen fibers were more represented in the straight surface of the implant. The implant fracture was correlated to crestal bone resorbing and subsequent fatigue yielding.

Overdentures on implants placed in bone augmented with fresh frozen bone

AIM

In the last decade several studies have been performed to evaluate the clinical outcome of one or two stage loaded implants supporting overdentures. Since fresh frozen bone (FFB) has an ever-increasing number of clinical applications and few reports are available on implants inserted into FFB, we performed a retrospective study on fixtures inserted in FFB and bearing overdentures.

METHODS

In the period between December 2003 and December 2006, 17 patients (14 females and 3 males with a median age of about 56 years) were grafted and 60 implants inserted thereafter. A total of 17 overdentures were delivered: 8 in the mandible and 9 in the maxilla. Multiple implant systems were used: 22 Double etched, 7 SLA, 9 Anodic oxidized, and 22 CaPo4 ceramic-blasted. Implant diameter ranged from 3.25 to 4.3 mm and length from 11.5 to 16.0 mm. Implants were inserted to replace 23 incisors, 9 cuspids, 20 premolars and 8 molars.

RESULTS

No implants were lost (i.e., survival rate=100%) and no differences were detected among the studied variables. Kaplan Meier algorithm and Cox regression did not reveal any statistical differences among the studied variables also as regards the success rate.

CONCLUSION

Implants inserted FFB and bearing overdentures have a high survival rate and success rates, which are comparable to those of implants inserted in non-grafted bone. FFB bone is a reliable material for alveolar ridge augmentation. No difference was detected among removable prostheses supported by two or more implants.

Restoration of locomotion in posttraumatic paraplegics: the multidisciplinary approach and unexpected plasticity of single neurons--facts and fantasy

In Europe there are about 300,000 paraplegics and in every country approximately 1000 new cases per year. Treatment requires a multidisciplinary approach with scientific cooperation targeted to exchange personal knowledge and expertise. At present a completely disrupted spinal cord cannot heal for recovery of motor and/or sensory functioning, although some promising treatment modalities in laboratory animal experiments have been reported. No interventional stem cell procedure so far has shown evidence to restore impaired functioning in human paraplegics. However, functional electrical stimulation (FES) via an implanted neuroprosthesis (SUAW concept) and central nervous system-peripheral nervous system (CNS-PNS) connection have successfully been used for alternative compensatory strategies for voluntary locomotion. This report is to analyse the authors' experience from two European projects in paraplegic. Factors will be identified that might have caused the one or other pitfall since so far both surgical reconstructive procedures have not been adopted by rehabilitation physicians and/or restorative (neuro-)surgeons despite the promising functional results we have achieved. Unexpected plasticity of single neurons following CNS-PNS by-pass procedures is discussed. Future interventions, for example the present phase 1 prospective multiple centre study on the side effects, effectiveness, and reliability of intrathecal treatment of anti-Nogo-A antibodies, are presented and the Chinese stem cell implantation is critically reviewed.

Adhesion reduction after knee surgery in a rabbit model by Hyaloglide, a hyaluronan derivative gel

A randomized controlled experimental trial was performed in a rabbit model of surgical adhesions to investigate the anti-adhesive effects of Hyaloglide, a highly viscous hyaluronan derivative absorbable gel after knee surgery. Twenty New Zealand white rabbits were prepared and randomly divided into two groups of 10 animals each. An intra-articular fibro-adhesive scar was created in the right knee joint of the hind paw of each rabbit using a standardized surgical procedure, and Hyaloglide was administered into the joint cavity of the knee at the end of intervention in the animals belonging to the treatment group. No anti-adhesive treatment was applied in the control group. Additionally, immobilization using a Kirschner wire was applied in order to increase the risk of adhesions. Six weeks after surgery the animals were euthanized and after removal of the immobilization system, adhesions were evaluated both macroscopically and histologically. Results of gross observations using a specific adhesion scoring system showed a significant reduction (p<0.01) of both incidence and severity of adhesions in the hyaluronan-treated group compared to the control group. Histologically, adhesions in the treated group were thinner with less collagenic fibers. In conclusion, Hyaloglide may be considered as a promising absorbable barrier for prevention of post-operative fibrotic adhesions after knee surgery.

[Finkelstein's versus Brunelli's test in De Quervain tenosynovitis]

This short paper demonstrates that the Finkelstein's test in De Quervain's tenosynovitis is based on an incorrect assumption. The correct basis for a pathognomic manoeuvre in De Quervain is the provocation of tendons attrition of the first wrist dorsal compartment against their pulley which elicits pain. The Brunelli's test induces this friction and pain by asking the patient to hardly adduct the thumb with the wrist in radial deviation.

Computer added locomotion by implanted electrical stimulation in paraplegic patients (SUAW)

Paraplegia means a live long sentence of sensory loss, paralysis and dependence with approximately 1000 new victims in every European country every year and 11.500 new traumatic SCI cases in the US. respectively. Sixty percent are injured before age 30. More than 90% of SCI victims may survive with nearly normal experience of live. Most patients will recover somewhat from SCI over time but no patient who remained plegic for one year regains voluntary motor function after that time period. Despite remarkable efforts and recent achievements in rehabilitation no treatment can be recommended so far to enhance functional recovery and restoring locomotion in paraplegic humans. FES as a technical compensation has become therefore a challenging treatment to restore muscle function and to prevent atrophy and to improve mobility and quality of life at the same time. In paraplegics FES could be the basis to restore locomotion. One of the advantages of an implanted FES version (neuroprosthesis) is that the FES system, electrodes, and cables remain permanently implanted within the body, so that the patient can stay without cables, the programmer attached to the crutches. The SUAW project, supported under BIOMED II Programme by the European Community was aimed to finalize and to put into practice the results of previous research and development. The novel implant with an ASCI-Chip has 16 channels, 8 on each side, 20 mA for monopolar and 2 mA for bipolar stimulation, only one electrode can be stimulated at a given time. Stimulation of 6 muscle groups of both legs are known to be sufficient for locomotion: M. ileopsoas (erector of the body, hip flexor), M. gluteus maximus (hip extensor), M. gluteus medius (lateral hip stabilisator, knee abductor), Mm. hamstrings (knee flexor) stimulated by epimysial electrodes, Mm. sartorius and rectus femoris (knee extensor) stimulated by neural, bipolar electrodes. Patient's selection criteria were: stable spinal cord lesion between T7 and T11, minimum 1 year after the accident without deformity of the spine, the muscle groups for locomotion responding to external FES with the EXOSTIM programmer with the same programme used later for the neuroprosthesis. Two paraplegic male patients, T8, 38 and 31 years old respectively, were operated on by an international group of surgeons according to the protocol in 09/1999, respectively 7/2000. The postop. course was uneventful. Because the threshold of the primary implant was too low regarding scare tissue around the electrodes, this implant was changed in 01/2000 and worked perfectly. Both patients are happy with the success of the novel treatment modalities.

Classification criteria and distinction between migraine and tension-type headache in children

The International Headache Society (IHS) classification system (1988) was developed primarily for headache disorders in adults and its validity for paediatric age is currently under discussion; in 1995 Seshia et al. proposed a revision of the criteria for migraine without aura to make diagnostic criteria more applicable to children. The purposes of the current study were to: (1) compare the IHS classification with the Seshia proposal, (2) compare the children affected by migraine without aura (MO) with the children affected by tension headache (TH) as defined by Seshia, for characteristics which are not included in the classification. The patients are a series of 320 children (mean age 9.9, SD 2.6 years; 144 males, 176 females) with recurrent or chronic headaches referred to a headache clinic in Milan, Italy. Using the Seshia criteria instead of the IHS criteria a higher number of children were included in the MO category: bilateral pain and family history of migraine were the most important factors which allowed a shift of children into this category. However, with the Seshia classification there was no reduction in the number of unclassifiable children. The reason why some children could not be classified was a short duration of attacks; the majority of unclassifiable children were 6 years old or less. No relevant difference was found between children with MO and children with TH for the following variables: occurrence of attacks in the afternoon or evening after school, reduction of attacks during school holidays, full-time schooling, after-school activities on school days, disordered daily life. On the contrary children with MO when compared with those with TH showed a higher number of precipitating factors and for the following factors a significant difference was found: exposure to TV or a computer, sleep deficiency, and strong emotions. Furthermore, children with MO showed a greater severity of attacks.

Linkage analysis of candidate endothelin pathway genes in nonsyndromic familial orofacial cleft

There is good evidence from linkage analysis and mouse model knockouts that the endothelin-1 gene (EDN1) is a good candidate for non-syndromic orofacial cleft (OFC) disease. EDN1 maps to the chromosomal region of the OFC1 locus in 6p23. Therefore we have examined three other candidate genes in the endothelin pathway (ECE1, EDNRA and EDNRB, which map to chromosomes 1, 4 and 13 respectively) in a linkage study of 9 families with OFC, where the disorder is not linked to chromosome 6p23. The total lod score for these 9 multiplex families never exceeded -2.00 and thus our data suggest that EDN1 and related genes are not involved in non-syndromic familial OFC.

Stage grouping of oropharyngeal cancer: evaluation of three systems by means of survival analysis

Stage grouping is a method of summarizing multiple categories generated from the tumor, node, metastasis (TNM) classification system. Recently three different systems, the T and N integer score (TANIS), Hart, and 1997 Union Internationale Contre le Cancer systems, have been proposed. To verify their correlation to survival, a series of 64 patients affected by primary squamous cell carcinoma of the oropharynx was considered in this retrospective study. The data set was classified according to Union Internationale Contre le Cancer T stage and then grouped as recommended by the three systems. Results showed a crude survival rate of 28.13%. Univariate analysis by means of the logrank test yielded significant P values for the T and N integer score and Hart systems (0.0452 and 0.0179, respectively) and a borderline P value (0.0728) for the stratification based on the 1997 Union Internationale Contre le Cancer system. Multivariate analysis (Cox regression adjusted for age and sex) showed a significant correlation between the three staging systems and the mortality rate. Odds ratios were 1.36 (95% confidence interval, 1.12-1.66), 1.58 (95% confidence interval, 1.18-2.12), and 1.63 (95% confidence interval, 1.08-2.48) for the T and N integer score, Hart, and 1997 Union Internationale Contre le Cancer systems, respectively. The T and N integer score system showed the best statistical correlation, but a conclusive result could not be achieved because of the low number of patients in this study.

[Selective microsurgical denervation in spastic paralysis]

Denervation, provosed at the turn of the century and abandoned because of inconstant results, has again been taken up in principle, but with a notable change in technique. It is necessary to do a careful examination of the muscles that are to be denervated (of the median and ulnar nerves) and to determine the nature of the spasticity. The incision, longer than in the original technique, allows a better view of the median and ulnar nerves. The nerve branches to each muscle are thus easily identified, and by electric stimulation during the operation one judges how much denervation to subject the muscles to while taking into account the phenomenon of the take-over of the denervated muscles by the remaining nerve fibers. Part of the nerve branches are then sectioned under microscopic control near the muscle, taking care to cauterize the proximal stump. It may be necessary to do associated tenotomies or capsulotomies. This method gives good results if the technique and the contraindications, (athetosis, chorea and cerebral deficits) are respected. It must be emphasized that the results depend on the degree of denervation, which is hardly quantifiable, and is subject to the operator's experience.

[Personal technique for suturing the flexor tendons of the fingers with immediate mobilization]

Immediate mobilization of flexor tendons repairs creates a conflict between muscle strength and suture solidity. Non removable sutures are brittle and require to prevent extension by means of either a cast in flexion of the wrist and of the metacarpo-phalangeal joints or a rubber band traction. Pull-out sutures do not permit early mobilization because of their anchorages. The authors present a new technique they have been using for the last five years. It consists in a simple solid slip-knot which tightening the tendon when the muscle pulls. This knot is fixed at the distal bone insertion of the tendon, which makes immediate mobilization possible. Sixty three patients have been treated with by this technique over the past five years. We have not encountered any rupture of the suture. The results, even in the least favorable cases have been considered as very good.

The role of allopurinol in preventing oxygen free radical injury to skeletal muscle and endothelial cells after ischemia-reperfusion

One of the most important mechanisms in the production of ischemic damage after replantation surgery is the rise of oxygen free radicals during revascularization of ischemic tissues. Free radicals produce damage in the cell membranes (lipoperoxydation). This occurs not only in muscle tissue, but also in endothelial cells, with a consequent increase of local edema and the risk of compartment syndrome. This study attempted to interrupt the ischemic-reperfusion injury process in ischemic rat hindlimbs. Complete ischemia was induced for different numbers of hours (3, 6, 9, 12 hr) in four groups of rats (24 animals in each group). Allopurinol, an oxygen free radical scavenger, was tested in solution, 12.5 mg/kg b.w., in half the studied animals (n = 12). Collected data showed an increase (mean value: 0.60 nM/mg 3 hri 0.90 nM/mg at 6 hr; 0.80 nM/mg at 9 hr; 0.89 nM/mg at 12 hr; mean value in nonischemic muscle = 0.526 nM/mg) in lipoperoxides (NS between treated/untreated groups, p > 0.05) and high tissue pressure values in the posterior compartment of the ischemic rat hindlimbs. Allopurinol reduced the pressure values (p < 0.05 in Groups 1-3; p < 0.1 in Group 4), but was not effective in reducing lipoperoxides in skeletal muscle.

[Dorso-cubital flap of the thumb. An anatomical study with clinical applications. Apropos of 22 cases]

The arterial supply of the dorsal surface of 25 thumbs was studied by light microscopy. An artery, located on the dorso-ulnar side and connecting the head of the first metacarpal bone with the dorsal arcade of the nail matrix, was constantly found in all dissections. The authors report the results of the anatomical study and the clinical applications of a skin flap which can be raised on the dorso-ulnar surface of the M.P. joint with a distal pedicle. Clinical experience is based on 22 flaps. In 18 cases this flap was used for distal skin loss coverage (palmar or dorsal) of the thumb as an island flap. In 4 cases it was used for reconstruction of the finger pulp in the form of a cross finger flap.

[The implantation of a heterologous prosthesis in reparative abdominal-thoracic surgery. Experience with the use of clindamycin in preventing prosthesis-related infection]

The authors point out how infection of heterologous prosthesis, widely used in surgery, can be a dramatic event. On the other hand, antibiotic prophylaxis is difficult because of the difference between "in vitro" and "in vivo" activity of many antibiotics, due to the production, by many bacteria, of the so-called glycocalyx. This would allow bacteria to clump and adhere to many surfaces, forming micro-colonies, causing delay in phagocytosis, and reducing the efficacy of antibiotics. On the basis of their, although limited, experience, the authors suggest, for the prophylaxis of prosthesis infection, the use of antibiotics such as clindamycin, able to reduce glycocalyx production.

Bridging nerve defects with combined skeletal muscle and vein conduits

The use of vein or muscle grafts to bridge nerve defects longer than 1-1.5 cm gives poor results. Veins collapse and in muscle grafts axons may regrow outside the graft. We used veins (to guide regeneration) filled with muscle (to avoid vein collapse). Nerve regeneration through 1 and 2 cm grafts made of vein plus muscle was compared with similarly long traditional nerve grafts, free fresh muscle grafts, and empty vein grafts. Regeneration was assessed clinically and histologically (qualitative and quantitative evaluation) in the graft and distal nerve stumps. Vein plus muscle grafts were superior to vein and fresh muscle grafts both functionally and histologically. Functional results were similar to those found in traditional nerve grafts, but axon number was superior in the veins filled with muscle. This suggests that vein filled with muscle might serve as a grafting conduit for the repair of peripheral nerve injuries and could give better results than traditional nerve grafting.

Acute cholecystitis: ultrasonographic staging and percutaneous cholecystostomy

Experience in the treatment of acute cholecystitis with percutaneous cholecystostomy in 29 high-risk and elderly patients is reported. The treatment group included 14 men and 15 women, 21 of whom were over 70 years of age. The suspected clinical diagnosis of acute cholecystitis was confirmed in all cases by ultrasonography (accuracy: 95.6%). The percutaneous cholecystostomy was successful in 27 of 29 cases and these patients had a sudden improvement in their clinical condition; failure of the procedure was due in one patient to dislodgement of the catheter and in another patient to the guide-wire slipping out of the gallbladder. Six patients complained of pain radiating to the right shoulder which disappeared within 30-60 minutes after the procedure. Twenty-three of the 27 patients subsequently underwent elective cholecystectomy. In 22 patients the ultrasonographic findings were compared with the histology; thus enabling us to establish an ultrasonographic staging of acute cholecystitis related to the seriousness of the disease. Percutaneous cholecystostomy is the treatment of choice in high-risk patients, in the elderly, as well as in young patients with impending perforation.

[The treatment of acute cholecystitis by percutaneous cholecystostomy]

The authors report on their personal experience with percutaneous cholecystostomy (PC) in 36 cases of acute cholecystitis (AC). PC was successful in 34 cases, improving the clinical condition of the patients within the first hour following treatment and normalizing the laboratory data within 24-48 hours. Twenty-seven patients with calculous AC underwent cholecystectomy within 4-15 days. In 6 cases (3 calculous and 3 acalculous ACs) PC was the only treatment performed; in one case (calculous AC) PC was combined with lithotomy, the stone fragments being extracted via the cholecystostomy. According to literature reports, to date PC has been performed mainly--as an alternative to surgical cholecystostomy--on the patients unsuitable for cholecystectomy due to their age or to severe impairment of their conditions. In our experience, the procedure can be performed on a wider range of patients as a final (notably in acalculous AC) or temporary step (notably in calculous AC where it may allow cholecystectomy to be delayed and thus performed under better clinical conditions, with decreased morbidity and mortality risks).

Diagnostic criteria for migraine and psychogenic headache in children

The headache histories obtained from 214 children were analysed by computer to see whether it was possible to identify and classify migraine, and to distinguish children with psychogenic headache. During headache attacks, most children had no or very few associated symptoms. For classification, 175 patients were divided into four homogeneous groups; the remaining 39 could not be grouped. An overlap between the different groups was found. Psychogenic headache emerged as a clearly definable syndrome, characterised by psychological problems and daily headache for a period of at least one month (10 patients). When the 214 patients were grouped according to the classification of the Headache Classification Committee of the International Headache Society, distinguishing those children with psychogenic headache was no longer possible.

Gnostic rings: usefulness in sensibility evaluation and sensory reeducation

The benefit of additional clinical tools for quantifying patients' ability to recognize objects is clear, as well as its correlation with the moving two-point discrimination test. The recognition of letters is such a tool. The authors describe gnostic rings, an additional technique, that is useful for clinical sensibility testing, as well as for sensory reeducation.

[Sensory retraining of the hand using gnosis rings]

Sensory reeducation is very important. Many methods are used but it is difficult to assess their efficiency. Besides the routine methods we are using the gnostic rings which have on their periphery 5 symbols: a letter = A, a number = 3, a geometrical figure = a circle, a rough surface and a smooth convex surface. The symbols of the rings are in 3 different sizes (1.5 - 1 and 0.5 cm). The gnostic rings have 3 advantages: 1) they allow a precise evaluation in percentage. 2) they require an important brain effort, 3) they may be kept in the pocket and used several times during the day.

Free microvascular fibular transfer for idiopathic femoral head necrosis: long-term follow-up

The authors discuss free microvascular bone transfers in general, and propose a new classification for idiopathic femoral head necrosis. They then present a technique they have been using for 11 years, with the goals of providing both mechanical support and an improved blood supply to the femoral head. This technique involves clearing the necrotic area of the femoral head, filling the area with cancellous bone taken from the greater and lesser trochanters, and transferring a fibular microvascular graft. The approach is transtrochanteric and spares the capsule. Vascular anastomosis is done with the lateral branches of the deep femoral artery, sparing the anterior circumflex artery which is important to the blood supply of the femoral head. Forty-five cases have been surgically managed over 11 years. Eighteen cases with follow-up longer than five years were analyzed, providing an 84 percent successful outcome with both very good and good results.

Compartmental syndrome due to viper bite

The case is reported of a young girl who was bitten on the hand by a viper and developed compartment syndrome of the intrinsic muscles more than 24 h later. Multiple dorsal and volar fasciotomies resolved the acute episode with complete restitutio ad integrum. The clinical case is discussed in detail and the literature on these rare complications of snake bites in European countries reviewed.

Free microvascular fibular versus conventional bone grafts

Free microvascular grafts have many advantages over conventional bone grafts. Above all they do not undergo creeping substitution and live on their own vessels, thus being able to heal quickly and fight infection. Research in rabbits has been done with radiographic, scintigraphic and light and fluorescence histologic examination which demonstrated the high superiority of quality, reliability and rapidity in healing of the microvascular bone transfer as related to avascular ones. Eighty-five cases of free microvascular fibular transfers starting in 1975 are presented including six congenital cases, 12 non-unions, eight osteitis, seven tumors, seven large losses of bone and 45 femoral head necrosis. The failure ratio is very low. Six primary failures were cured by plaster or additional cancellous bone grafts. Four failures (in femoral head necrosis) did not cure due to recession of the graft, its reabsorption or progression of avascular necrosis in two corticosteroid cases.

[The role of echo-guided percutaneous cholecystectomy in acute cholecystitis]

Personal experience in the treatment of acute cholecystitis with percutaneous cholecystostomy in high risk patients and in elderly patients is reported. Between January 1989 and November 1990, 28 patients affected by acute cholecystitis were treated with percutaneous cholecystostomy at Emergency Surgery Department, Verona University Hospital. The patients treated included 13 men and 15 women; 8 of them were under 70 years old, 5 between 70th and 75th and the remaining patients over 75 years old. The suspected clinical diagnosis of acute cholecystitis was confirmed in all cases by ultrasonography (accuracy 95.4%). The percutaneous cholecystostomy was successful in 26 over 28 cases. In all these cases patients had a sudden improvement of their clinical conditions. In one case we failed because the guide-wire slipped out of the gallbladder and we couldn't perform a second attempt for the patient's refuse; in an other case there was the dislodgment of the catheter after less than 12 hours from the cholecystostomy and the patient was operated on. Twenty-two of 26 patients whose conditions were improved by percutaneous cholecystostomy, subsequently underwent elective cholecystectomy. In 2 cases of acalculous cholecystitis the patients did not undergo the operation; in 2 cases because of the elderly age of the patients and their bad cardiorespiratory conditions we preferred not to perform the operation. We had not major complications; 6 patients complained pain irradiating to right shoulder which disappeared within 30-60 minutes from the end of the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

[The conservative treatment of hepatic abscesses with echo-guided transcutaneous drainage]

Liver abscesses are a rare disease with 80-100% mortality in untreated cases. The advent of ultrasound in the clinical practice has improved the prognosis. Surgery for this disease has a percentage of complications of 15-52% and a mortality of 12-33%. In a review of the literature about 200 liver abscesses treated with ultrasound-guided percutaneous drainage the complications were 7.5% and the mortality was 3%. The authors report their personal experience about 21 hepatic abscesses in 13 patients. Nineteen abscesses were treated with ultrasound-guided percutaneous drainage and two with antibiotics. Six patients had pyogenic liver abscesses, two amebic and in five patients the cultures were sterile. In 9 cases the location was in the right lobe of the liver, in 3 was in the left lobe. One patient had multiple abscesses. The size of the abscesses ranged from 0.5 to 13 cm. We drained with Seldinger technique or direct procedure with Trocar's needle under ultrasound guidance without serious complications and without mortality. In 6 cases the patients had pain during the procedure and in 3 cases medical therapy was necessary. In one case we had a pleuritis for the puncture of costophrenic space. All the patients treated had a complete resolution of the abscesses. The ultrasound-guided percutaneous drainage is the treatment of choice for liver abscesses. But other reports with more patients are necessary to clarify the indications and the ultrasound criteria of recovery.

[The therapy of symptomatic and/or complicated dysontogenetic liver cysts]

Congenital hepatic cysts are a frequent disease, symptomatic in the 16-18% of the cases. The authors report a review of the literature of the last 20 years about 135 treated surgically patients with symptomatic and/or complicated hepatic cysts. They analyse the different models of treatment both surgical and conservative, referring in special way about the alcoholization of the cysts. The authors finally report their personal experience about eight cases.

Strategy and timing of peripheral nerve surgery

The authors review the latest theories of peripheral nerve regeneration and repair. They present their research on nerve regeneration including the alterations in the mother cell body, and in the distal part of the axon, and the time required to reach the best production of amino acids for cytoskeleton reconstruction. Other research of particular interest which is presented regards the chemotactic arrangement of motor and sensory axons inside a vein. This research has shown that the axons are able to find their way to the appropriate (sensory or motor) distal endoneural tubes. Adoption phenomena are also presented. The discussion of surgery includes the type (suture, glueing, grafts, tubulization) and the time of surgical repair. Timing and repair strategies are related to the site of the lesion (which can require that a greater or smaller amount of cytoskeleton be reconstructed), the type of the injury, the state of surrounding tissues, the age of the patients, injuries to muscles, tendons, bones, vessels and skin. A scheme of strategy is proposed.

[Direct muscular neurotization]

The authors present a technique of direct muscular neurotization consisting of re-innervation by direct implantation of a nerve into one or several muscles in cases of avulsion of the nerve supplying the muscle or traumatic or surgical avulsion of the neural part of the muscle. The biological basis for this operation is that a denervated muscle can accept a new innervation by a foreign nerve even in an aneural zone because its sensitivity to acetylcholine is present throughout the muscle, while, in a normally innervated muscle, sensitivity to acetylcholine is confined to the motor endplates. The results of 47 cases are presented: 42 of them obtained good or very good results.

Experimental investigation of cross-nerve transfers relating to repair of brachial plexus avulsion injuries

There is a lack of agreement regarding the potential for peripheral nerve cells with short axons to regenerate and innervate the terminal end organs of nerve cells with long axons. We designed a study to evaluate experimentally the possibility of neurons to reconstitute much longer axonal segments. Twenty Wistar rats were used. The brachial plexus was isolated and the radial nerve transected immediately after its origin. The proximal end of the axillary nerve (previously cut) then was coapted tot he distal stump of the radial nerve. In 10 other rats, the cut radial nerve was simply recoapted to itself without involvement of the axillary nerve; these animals served as controls. Finally, in 10 rats, nerves were cut without repair to evaluate the degenerative changes. After 90 days, the distal part of the radial nerve was examined by light microscopy, calculating the number and area of regenerated axons. We also checked the motor end-plates of reinnervated muscles. In the nerve-transferred group, good axonal regeneration with good reinnervation of the muscles was seen. In this way, we have experimentally demonstrated a plasticity of regeneration in peripheral nerves. This suggests that the surgeon may use nerves connected to proximal muscles to neurotize avulsed nerves of distal muscles.

Role of the mediators in pulmonary hyperreactivity: the cocktail interaction hypothesis

Pulmonary hyperreactivity is a common feature in asthma. In the present study we investigated the possible role of different mediators in the genesis of this phenomenon. In particular the ability of prostaglandin D2 (PGD2), substance P (SP) and bradykinin (BK) to potentiate acetylcholine (ACh)-induced bronchospasm was assessed in anaesthetized and mechanically ventilated guinea-pigs. Threshold doses of PGD2, SP and BK significantly enhanced ACh-induced bronchospasm in normal guinea-pigs, even if a different trend in the onset and duration of the phenomenon was observed. Ovalbumin (OA) active sensitization modified the ability of the three compounds tested to positively interact with ACh. Beta-adrenoceptor blockade due to propranolol treatment increased the positive interaction between the three compounds and ACh. The role of PGD2, SP and BK in the genesis of pulmonary hyperreactivity is proposed and the relevance of mediator-mediator interaction during adrenergic imbalance is discussed.

[Technical considerations on 222 cases of esophageal anastomosis using a stapler]

The Authors report their experience with 222 esophagoenteric anastomoses, performed in 211 cases for malignant neoplasms (middle and lower third) of the esophagus or stomach. Particularly, they have performed 4 Sujura operations, 31 esophagogastric, 4 esophagocolic, 183 esophagojejunal anastomoses utilizing SPTU, ILS and EEA circular stapler. GIA was used in the preparation of the stomach before esophagogastroplasty. Mortality rate of the manual period (1970-1980: 114 cases operated) was 14.5% versus 2.2% of the stapling period (1981-1987: 222 cases operated). From the technical point of view reasons of the superiority of stapled technique are discussed and summarized as follows: 1) space not favourable for handsewn anastomoses; 2) stapled technique allows the surgeon to save anastomoses vascularization; 3) the stapler performs the suture simultaneously so to reduce tensile strength on the anastomoses and the fragile esophageal wall especially; 4) stapled agraphes are fixed in three points vs. the two points of the handsewn stitches.