A foundation for evaluating the surgical artificial intelligence literature

With increasing growth in applications of artificial intelligence (AI) in surgery, it has become essential for surgeons to gain a foundation of knowledge to critically appraise the scientific literature, commercial claims regarding products, and regulatory and legal frameworks that govern the development and use of AI. This guide offers surgeons a framework with which to evaluate manuscripts that incorporate the use of AI. It provides a glossary of common terms, an overview of prerequisite knowledge to maximize understanding of methodology, and recommendations on how to carefully consider each element of a manuscript to assess the quality of the data on which an algorithm was trained, the appropriateness of the methodological approach, the potential for reproducibility of the experiment, and the applicability to surgical practice, including considerations on generalizability and scalability.

Gut-oriented interventions in patients with multiple sclerosis: fact or fiction?

OBJECTIVE

Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating, disimmune disease of the central nervous system whose etiology and pathogenesis remain poorly understood, due to its complex and multifactorial nature. Evidence of a bidirectional connection linking the gut microbiome with the intestinal barrier and the immune system (the gut-brain axis) may have implications for the pathogenesis of inflammatory demyelinating diseases such as MS. This narrative review summarizes the evidence for the gut-brain axis involvement in the pathogenesis of MS and examines the role of gut-oriented interventions in MS.

PATIENTS AND METHODS

We reviewed all available studies in PubMed concerning gut-directed interventions and MS. This research was conducted using different combinations of pertinent keywords (multiple sclerosis, immune-mediated inflammatory diseases, autoimmune diseases, first demyelinating event, neurocognition, neurological disorders, neurology practice, risk factors, taxonomic biomarkers, nutrition, diet, dietary additives, complementary treatment, gut bacteria, gut microbiome, microbiome, gut-brain axis, epidemiology, alpha-linolenic acid, fermentative metabolites, fat, saturated fat, monounsaturated fat, polyunsaturated fat, omega-3 fatty acids, calorie restricted diet, fasting, fecal microbiome, fecal microbiota transplantation, animal testing).

RESULTS

There is an emerging evidence that alterations in the gut microbiome and increased intestinal permeability may be causative factors in the complex interplay between nutrition, metabolic status and the immune-inflammatory response in patients with MS. This suggests the possibility that modification of lifestyle and the microbiome, for example by specific diets or fecal microbiota transplantation, supplementation with bile acids and intestinal barrier enhancers, may positively influence the pathogenesis of MS.

CONCLUSIONS

Although the role of nutritional factors in the pathogenesis of MS remains to be established, there is evidence that appropriate gut-directed interventions such as diet, nutritional supplementation or fecal transplantation may modulate the inflammatory response and improve the course of MS as a complementary treatment in the disease.

Sapienza Global Bedside Evaluation of Swallowing after Stroke: the GLOBE-3S study

BACKGROUND AND PURPOSE

Dysphagia occurs in up to 50% of all patients with acute stroke. There is debate regarding which is the most effective screening tool in identifying aspiration in patients with acute stroke. We assessed the accuracy of the Sapienza Global Bedside Evaluation of Swallowing after Stroke (GLOBE-3S), which combines the Toronto Bedside Swallowing Screening Test (TOR-BSST©) with oxygen desaturation and laryngeal elevation measurement during swallowing.

METHODS

We prospectively enrolled consecutive patients with stroke within 72 h of symptom onset. All patients with stroke firstly underwent a standard neurological examination, then the GLOBE-3S evaluation and finally the fiberoptic endoscopic evaluation of swallowing (FEES). Two different assessors, a neurologist and a speech pathologist, blind to both the clinical data and each other's evaluation, administered the GLOBE-3S and FEES examination. We assessed the accuracy of the GLOBE-3S in detecting post-stroke swallow impairment with aspiration using the FEES as the standard.

RESULTS

We enrolled 50 patients with acute stroke, 28 of whom (56%) had swallowing impairment with aspiration at FEES evaluation. A total of 33 patients (66%) failed the GLOBE-3S evaluation. The GLOBE-3S reached a sensitivity of 100% and a specificity of 77.3% (negative predictive value, 100%; positive likelihood ratio, 4.34). The median time required for the GLOBE-3S to be performed was 297 s.

CONCLUSIONS

GLOBE-3S is quick to perform at the bedside and can accurately identify aspiration in patients with acute stroke. By including the measurement of laryngeal elevation and monitoring of oxygen desaturation, it could represent a highly sensitive instrument to avoid the misdiagnosis of silent aspirators.

Hepatitis E virus infection mimicking acute graft rejection in a liver transplant recipient

INTRODUCTION

In liver transplant (LT) patients, hepatitis E virus (HEV) can lead to acute liver failure, chronic hepatitis and graft cirrhosis. Few data on graft rejection associated with HEV are available and are subject to discussion.

CASE REPORT

Here we report the case of a 58-year-old male patient who underwent LT in July 2015 for cirrhosis due to NASH and chronic alcohol intake complicated by hepatocellular carcinoma. LT was performed with a deceased donor isogroup and a mismatch CMV (donor+ and recipient-). HEV serology was negative before LT. In February 2016, we noted abnormal liver function, with increased transaminases and cholestasis parameters, without functional complaints. The patient was immunosuppressed by tacrolimus (4mg) and everolimus (2mg). Abdominal ultrasound was normal and liver biopsy showed signs of acute rejection (Banff score 6/9). We dispensed 500mg of methylprednisolone before obtaining positive serological results for HEV genotype 3 infection. Ribavirin (1,200mg per day) for 3 months was started, leading to rapid improvement in liver tests. Viral load became negative one month later. To date, the patient is under LP 5mg tacrolimus with normal liver tests.

CONCLUSION

We describe a case of HEV genotype 3 infection mimicking acute cellular rejection, with a favorable outcome due to ribavirin treatment. As intensive immunosuppressive therapy administered for graft rejection may promote viral replication and worsen liver damage, potential HEV infection must be considered in cases of pathological signs of acute cellular rejection, in order to avoid chronic graft hepatitis, cirrhosis and liver decompensation.

Hospital Charge and Health-Care Quality in Bariatric Surgery

To determine if hospital charges correlate with patient outcomes after bariatric surgery. A retrospective review of 46,180 patients who underwent bariatric surgery from 2004-2010 was performed. Patients were identified using the New York Statewide Planning and Research Cooperative System database. Hospitals were categorized on estimates from a multiple linear regression model for charge: low (<$25,027.00), medium ($25,027.00-$35,449.00), and high (≥$35,449.01). Patient outcomes were compared among the charge classification. Of the 46,180 patients, 24 per cent underwent operations in low-, 26 per cent in medium-, and 23,082 (50%) in high-charge hospitals. Controlling for patient demographics, comorbidity, insurance, and operative procedure, multivariable logistic regression demonstrated no significant difference in major complication or mortality among charges. Hospital charge does not correlate with improved outcomes. This is significant given the adverse association between price inflation and rising insurance premiums. Inflated hospital charges may also discriminate against certain patient populations including the uninsured and those with high-deductible insurance plans.

Hospital Charge and Health-Care Quality in Bariatric Surgery

To determine if hospital charges correlate with patient outcomes after bariatric surgery. A retrospective review of 46,180 patients who underwent bariatric surgery from 2004-2010 was performed. Patients were identified using the New York Statewide Planning and Research Cooperative System database. Hospitals were categorized on estimates from a multiple linear regression model for charge: low (<$25,027.00), medium ($25,027.00–$35,449.00), and high (≥$35,449.01). Patient outcomes were compared among the charge classification. Of the 46,180 patients, 24 per cent underwent operations in low-, 26 per cent in medium-, and 23,082 (50%) in high-charge hospitals. Controlling for patient demographics, comorbidity, insurance, and operative procedure, multivariable logistic regression demonstrated no significant difference in major complication or mortality among charges. Hospital charge does not correlate with improved outcomes. This is significant given the adverse association between price inflation and rising insurance premiums. Inflated hospital charges may also discriminate against certain patient populations including the uninsured and those with high-deductible insurance plans.

Hospital admissions greater than 30 days following bariatric surgery: patient and procedure matter

INTRODUCTION

Assessment of hospital admission in the 30-day period following bariatric surgery likely underestimates true hospital utilization. The purpose of this study is to assess hospital admissions for 2 years following bariatric surgery to identify potential differences by patient and procedure.

METHODS

New York State Planning and Research Cooperative System (SPARCS) longitudinal administrative data were used to identify 22,139 adult patients who underwent a primary bariatric surgery from 2006 to 2008. Bariatric operations included laparoscopic gastric banding (LGB), laparoscopic Roux-en-y gastric bypass (RYGB), and laparoscopic sleeve gastrectomy (LSG). Patients were followed for 2 years after surgery to identify all-cause hospital admissions. Statistical correlation between postoperative hospital admission and patient demographics, comorbid conditions, and bariatric procedure was performed.

RESULTS

Of the 22,139 patients, 5,718 (26 %) patients were admitted within 2 years of surgery for a total of 9,502 admissions. Thirty-day admission rate was 5 %. The number of admissions per patient ranged from 1 to 22. Assessing the number of admissions per patient demonstrated that 3,741 (17 %) patients had one, 1,575 (7 %) had 2-3, and 402 (2 %) patients had greater than 4 admissions. LSG had both the highest admission rate and percentage of patients with >4 admissions, followed by RYGB and then LGB (p < 0.001). Risk factors for admission included black race, female gender, age > 50, Medicaid/Medicare as payer, congestive heart failure, pulmonary disease, diabetes, rheumatoid arthritis, history of substance abuse, and psychoses/depression.

CONCLUSION

One out of four bariatric patients will be admitted to the hospital within 2 years of surgery. While most patients are admitted only once, a subset of patients requiring numerous hospital admissions was identified. LSG is associated with both the highest rate as well as highest frequency of hospital admissions. Several patient factors were also identified that significantly increased admission risk. Consideration and attention to these factors are necessary for operative planning, preoperative patient education, and postoperative monitoring.

Perioperative outcome of esophageal fundoplication for gastroesophageal reflux disease in obese and morbidly obese patients

BACKGROUND

To determine the perioperative safety of esophageal fundoplication for gastroesophageal reflux disease (GERD) in patients with body mass index (BMI) ≥ 35 kg/m(2).

METHODS

A retrospective review of 4,231 patients who underwent fundoplication for GERD from 2005 to 2009 was performed. Patients were identified via National Surgical Quality Improvement Program and grouped by BMI < 35 versus BMI ≥ 35 kg/m(2). Univariate analysis compared 30-day outcomes.

RESULTS

Of the 4,231 patients, 3,496 (83%) had BMI < 35 kg/m(2) and 735 (17%) had BMI ≥ 35 kg/m(2). Mean BMI for each cohort was 27.9 versus 39.1, respectively. Patients with BMI ≥ 35 kg/m(2) had significantly longer operative times (129.7 vs 118 minutes, P < .0001) and increased American Society of Anesthesiologists scores (2.43 vs 2.3, P = .001). The overall complication rate was 1.96%. No difference was demonstrated by BMI in complication rate or hospital length of stay. Increased American Society of Anesthesiologists score, diabetes, black race, longer operative time, and intraoperative transfusion significantly increased postoperative complication rates.

CONCLUSIONS

No increased risk is conferred to morbidly obese patients who undergo fundoplication for GERD management. This study identified independent patient risk factors for postoperative complication following esophageal fundoplication.

Hepatic artery ligation for arterial rupture following liver transplantation: a reasonable option

Hepatic artery (HA) rupture after liver transplantation is a rare complication with high mortality. This study aimed to review the different managements of HA rupture and their results. From 1997 to 2007, data from six transplant centers were reviewed. Of 2649 recipients, 17 (0.64%) presented with HA rupture 29 days (2-92) after transplantation. Initial management was HA ligation in 10 patients, reanastomosis in three, aorto-hepatic grafting in two and percutaneous arterial embolization in one. One patient died before any treatment could be initiated. Concomitant biliary leak was present in seven patients and could be subsequently treated by percutaneous and/or endoscopic approaches in four patients. Early mortality was not observed in patients with HA ligation and occurred in 83% of patients receiving any other treatment. After a median follow-up of 70 months, 10 patients died (4 after retransplantation), and 7 patients were alive without retransplantation (including 6 with HA ligation). HA ligation was associated with better 3-year survival (80% vs. 14%; p=0.002). Despite its potential consequences on the biliary tract, HA ligation should be considered as a reasonable option in the initial management for HA rupture after liver transplantation. Unexpectedly, retransplantation was not always necessary after HA ligation in this series.

Report of the first peritoneal dialysis program in Guyana, South America

INTRODUCTION

In 2008, we initiated the first Guyanese comprehensive kidney replacement program, comprising hemodialysis (HD), peritoneal dialysis (PD), vascular access procedures, and living-donor kidney transplantation. The government of Guyana, US-based philanthropists, US-based physicians, and Guyanese caregivers teamed up to form a public-private partnership. This pilot program was free of cost to the patients.

METHODS

From July 2010 to the time of writing, we placed 17 patients with end-stage kidney disease on PD, which was used as a bridge to living-donor kidney transplantation. During the same period, we placed 12 primary arteriovenous fistulae.

RESULTS

The 17 patients who received a PD catheter had a mean age of 43.6 years and a mean follow-up of 5.3 months. In that group, 2 deaths occurred (from multi-organ failure) within 2 weeks of catheter placement, and 2 patients were switched to HD because of inadequate clearance. Technical issues were noted in 2 patients, and 3 patients developed peritonitis (treated with intravenous antibiotics). An exit-site abscess in 1 patient was drained under local anesthesia. The peritonitis rate was 0.36 episodes per patient-year. Of the 17 patients who received PD, 4 underwent living-donor kidney transplantation.

CONCLUSIONS

In Guyana, PD is a safe and cost-effective option; it may be equally suitable for similar developing countries. In Guyana, PD was used as a bridge to living-donor kidney transplantation. We have been able to sustain this program since 2008 by making incremental gains and nurturing the ongoing public-private partnership.

Effect of smoking on kidney transplant outcomes: analysis of the United States Renal Data System

BACKGROUND

We investigated the effect of smoking on postkidney transplant outcomes in the United States Renal Data System.

METHODS

In a retrospective cohort of 41,705 adult Medicare primary renal transplant recipients in the United States Renal Data System database transplanted from January 1, 2000, to June 30, 2006, and followed through October 31, 2006, we assessed Medicare claims for smoking. The association between renal allograft loss and death and smoking as a time-dependent variable was assessed with Cox nonproportional hazards regression.

RESULTS

Of 41,705 Medicare primary adult renal transplant patients, there were 9.9% patients who had evidence of prior smoking and 4.6% patients with new claims for smoking after transplant. Incident smoking (new onset smokers) occurred at a mean of 1.29±0.88 years after transplant. In the adjusted analysis, factors associated with new smoking included male gender, history of drug or alcohol use, history of chronic obstructive pulmonary disease, and later year of transplant. Compared with never smokers, incident smoking after transplant was associated with increased risk of death-censored allograft loss (adjusted hazard ratio [AHR] 1.46 [95% confidence interval {CI}: 1.19-1.79]; P<0.001) and death (AHR 2.32 [95% CI: 1.98-2.72]; P<0.001). In a sensitivity analysis excluding patients with history of chronic obstructive pulmonary disease, similar results were obtained with increased risk of death-censored allograft loss (AHR 1.43 [95% CI: 1.16-1.76]; P=0.001) and death (AHR 2.26 [95% CI: 1.91-2.66]; P<0.001).

DISCUSSION

Incident smoking was detrimental to graft and patient survival. Transplant programs should screen those at risk during transplant follow-up and have smoking cessation programs.

Depression after minor stroke: prevalence and predictors

BACKGROUND AND PURPOSE

Post-stroke depression (PSD) is one of the most frequent complications of stroke, with a prevalence ranging 20-60%. As PSD seems to be related to stroke severity, we hypothesized that the prevalence of PSD would be lower in patients with minor stroke.

METHODS

We investigated the prevalence and predictors of PSD over a 30-month follow-up period in a cohort of patients with minor ischaemic stroke (NIHSS≤5).

RESULTS

We enrolled 105 patients (mean age 64.38±11.2years, M/F 69/36). PSD was diagnosed in 43 (41%) patients, 40 (93%) of whom had dysthymia; 22% of patients were already depressed at 1month. The most frequent depressive symptoms (DSs) were working inhibition, indecisiveness, and fatigability. Patients who developed PSD were less educated (P=0.044) and diabetic (P=0.006). After excluding patients that were already depressed at 1month, we performed a logistic regression model to detect predictors of PSD. Crying (P=0.012, OR 1.067, CI 0.269-4.553) and guilt (P=0.007, OR 0.037, CI 0.02ì03-0.401) at baseline were two DSs found to be significantly correlated with PSD. Higher educational level (P=0.022, OR 0.084, CI 0.010-0.698) and diabetes (P=0.007, OR 14.361, CI 2.040-101.108) were the risk factors significantly correlated with PSD.

CONCLUSION

Post-stroke depression is frequent even in patients with minor stroke. Early detection of DSs might help to predict long-term development of PSD. No correlation was observed between lesion site or side and the development of PSD.

Poor outcomes in elderly kidney transplant recipients receiving alemtuzumab induction

INTRODUCTION

Alemtuzumab and rabbit antithymocyte globulin (rATG) are being used with increasing frequency as induction agents in kidney transplantation. Using the US Renal Data Base System, we analyzed the safety profile of these agents in the elderly.

METHODS

In a cohort of patients transplanted from January 2000 to July 2009 and followed through 2009, we assessed the effect of induction on allograft loss and death among elderly recipients. Recipients were censored at dates of allograft loss, death or the end of study. Independent associations between induction agents and allograft loss or death were examined using multivariate analysis with forward stepwise Cox regression.

RESULTS

Among 130,402 patients with first transplants, 14,907 were age 65 years or older. 4,466 (30%), 3,049 (20.5%), 1,501 (10.1%), and 999 (6.7%) were induced with thymoglobulin, basiliximab, daclizumab, and alemtuzumab, respectively. After adjusting for baseline differences, induction with alemtuzumab was associated with an increased risk of graft loss and death, with an adjusted hazard ratio (AHR) of 1.26 (95% CI 1.08-1.48). Risk was also present at other age cutoffs [age >60 (AHR 1.16; 95% CI 1.03-1.31; p = 0.014), age >70 (AHR 1.43; 95% CI 1.13-1.81; p = 0.003) and age >75 (AHR 1.68; 95% CI 1.07-2.63; p = 0.024)].

CONCLUSIONS

In the elderly, alemtuzumab is associated with an escalating risk of death and graft loss in recipients of kidney transplantations.

Topical tacrolimus for parastomal pyoderma gangrenosum: a report of two cases

Pyoderma gangrenosum (PG) is an idiopathic, ulcerative, inflammatory dermatologic condition that occurs in patients with systemic diseases such as inflammatory bowel disease (IBD). This inflammatory skin disorder is presumably caused by an autoimmune mechanism and the diagnosis is one of exclusion. PG is not a common condition but it is thought to account for approximately 50% of chronic parastomal ulcers. Refractory parastomal PG (PPG) occurs in patients with inactive disease or after bowel resection. Multiple medical treatments, ranging from topical agents for mild disease to systemic immunosuppressive therapy for severe disease, have been used with varying rates of success. Using topical tacrolimus, an immunosuppressant that inhibits T-lymphocyte proliferation, and meticulous stoma care can result in successful treatment. Two women (ages 59 and 62 years) with a history of ulcerative colitis and colon resection presented with parastomal ulcers consistent with PPG. The 59-year patient presented with a painful 2 cm x 2 cm parastomal ulcer that improved following daily application of topical tacrolimus 0.1%. The 62-year old woman first was prescribed daily appliance changes and application of topical triamcinolone 0.5% to her 3-cm ulcer. The ulcer increased in size and treatment was changed to daily application of tacrolimus 0.1%. After 2 months and a reduction in ulcer size and severity, the dosage was changed to daily application of tacrolimus 0.03%. Both patients reported resolution of pain and itching, the most common symptoms of PPG, and no adverse effects were observed. The encouraging results observed in these two cases confirm that tacrolimus helps resolve PPG lesions even at concentrations previously thought to be ineffective. Additional studies to help clinicians optimize care of these painful lesions are needed.

Combined Pharmacological and Short-Term Psychodynamic Psychotherapy for Probable Medication Overuse Headache: A Pilot Study

We studied the effects of short-term psychodynamic psychotherapy (STPP) and pharmacological therapy in 26 consecutive patients with probable medication overuse headache (pMOH). Patients underwent a standard in-patient detoxification protocol, lasting a mean of 7 days. Eleven patients overused non-steroidal anti-inflammatory drugs (NSAIDs), five a combination of NSAIDs and triptans, four triptans, four a combination of NSAIDs, and three triptans and ergot derivates. Preventive therapy was initiated during detoxification. The STPP protocol comprised the Brief Psychodynamic Investigation (BPI) and psychoanalysis-inspired psychotherapy. All patients (groups A and B) underwent the BPI and pharmacological therapy. Half of the patients (group B) also not randomly underwent psychoanalysis-inspired psychotherapy. We found a significant interaction between time and group for headache frequency and medication intake. At 12-month follow-up, a statistically greater decrease in headache frequency and medication intake was observed in group B than in group A ( P = 0.0108 and P = 0.0097, respectively). The relapse rate was much lower in group B patients at both 6 and 12 months [15.3%, odds ratio (OR) 0.11, P = 0.016, and 23%, OR 0.18, P = 0.047, respectively] than in group A. The risk of developing chronic migraine (CM) during follow-up was higher in group A than in group B at 6 (OR 2.0, P = 0.047) and 12 months (OR 2.75, P = 0.005). Our study suggests that STPP in conjunction with drug withdrawal and prophylactic pharmacotherapy relieves headache symptoms in pMOH, reducing both long-term relapses and the burden of CM.

Short-term evolution as a marker of vascular dementia versus Alzheimer's disease

The diagnosis of vascular dementia (VaD) remains a controversial issue in many aspects and concepts. These nosologic problems are caused both by the methods, insufficient to ascertain the diagnosis, as well as by the weak consistency of the clinical concept of VaD itself. One of the most intriguing issues on VaD, and in particular on post-stroke dementia (PSD), is related to the time of development of cognitive decline. In clinical practice, the 3-month time threshold is usually chosen to enable resolution of a possible acute post-stroke delirium, and to obtain a more reliable cognitive assessment with a complete regression of acute neuropsychological stroke-related deficits. Another relevant issue is the possibility to predict which patient will develop PSD. In this regard, recent data indicate an overlap between Alzheimer's disease (AD) and PSD, which seems to share risk factors and neuropathology. In most population samples these two disorders appear together, and the consensus is growing that a degenerative component has a more important role in determining PSD onset shortly after stroke than previously recognized. Therefore, anamnestic data have a fundamental role in this prognostic approach.

Microarray analysis of cultured human brain aggregates following cortisol exposure: implications for cellular functions relevant to mood disorders

Increased cortisol levels in humans are often observed in patients suffering from mood disorders. In this study human fetal brain aggregates were exposed to cortisol at 500 nM for 3 weeks, as an in-vitro model of chronic cortisol exposure. Microarray analysis on extracted mRNA using the Affymetrix U133A platform was then performed. Our results demonstrated a significant effect of cortisol on 1648 transcripts; 736 up-regulated and 912 down-regulated genes. The most differentially regulated biological categories were: RNA processing, protein metabolism, and cell growth. Within these categories we observed a down-regulation of fibroblast growth factor 2 (FGF2) (-1.5-fold) and aquaporin4 (AQP4) (-1.7-fold), alongside an up-regulation of fibroblast growth factor 9 (FGF9) (+1.7-fold) and vesicle associated membrane protein2 (VAMP2) (+1.7-fold). FGF2, FGF9, AQP4 and VAMP2 changes were confirmed at the protein level by immunohistochemistry. Alterations in FGF transcripts are in keeping with recent literature demonstrating such effects in patients with mood disorders.

Intracytoplasmic maturation of the human immunodeficiency virus type 1 reverse transcription complexes determines their capacity to integrate into chromatin

Background

The early events of the HIV-1 life cycle include entry of the viral core into target cell, assembly of the reverse transcription complex (RTCs) performing reverse transcription, its transformation into integration-competent complexes called pre-integration complexes (PICs), trafficking of complexes into the nucleus, and finally integration of the viral DNA into chromatin. Molecular details and temporal organization of these processes remain among the least investigated and most controversial problems in the biology of HIV.

Results

To quantitatively evaluate maturation and nuclear translocation of the HIV-1 RTCs, nucleoprotein complexes isolated from the nucleus (nRTC) and cytoplasm (cRTC) of HeLa cells infected with MLV Env-pseudotyped HIV-1 were analyzed by real-time PCR. While most complexes completed reverse transcription in the cytoplasm, some got into the nucleus before completing DNA synthesis. The HIV-specific RNA complexes could get into the nucleus when reverse transcription was blocked by reverse transcriptase inhibitor, although nuclear import of RNA complexes was less efficient than of DNA-containing RTCs. Analysis of the RTC nuclear import in synchronized cells infected in the G2/M phase of the cell cycle showed enrichment in the nuclei of RTCs containing incomplete HIV-1 DNA compared to non-synchronized cells, where RTCs with complete reverse transcripts prevailed. Immunoprecipitation assays identified viral proteins IN, Vpr, MA, and cellular Ini1 and PML associated with both cRTCs and nRTCs, whereas CA was detected only in cRTCs and RT was diminished in nRTCs. Cytoplasmic maturation of the complexes was associated with increased immunoreactivity with anti-Vpr and anti-IN antibodies, and decreased reactivity with antibodies to RT. Both cRTCs and nRTCs carried out endogenous reverse transcription reaction in vitro. In contrast to cRTCs, in vitro completion of reverse transcription in nRTCs did not increase their integration into chromatin.

Conclusion

These results suggest that RTC maturation occurs predominantly in the cytoplasm. Immature RTCs containing RT and incomplete DNA can translocate into the nucleus during mitosis and complete reverse transcription, but are defective for integration.

Delayed poststroke dementia: A 4-year follow-up study

OBJECTIVE

To assess patients who have had a stroke for the subsequent development of poststroke dementia (PSD) and to determine if the characteristics of delayed PSD (dPSD) vary in the long-term follow-up.

METHODS

Nondemented patients were followed from 6 months after stroke onset for 4 years. Dementia was diagnosed by International Classification of Diseases-10 criteria; dementia etiology was diagnosed by the National Institute of Neurological and Communication Disorders and Stroke/Alzheimer's Disease and Related Disorders Association and National Institute of Neurologic Disorders and Stroke/Association Internationale pour la Recherche et l'Enseignement en Neurosciences criteria. Neuroimaging and neuropsychological tests were repeated annually.

RESULTS

During a 2-year period, 191 stroke patients were enrolled. By the end of the follow-up period, 41 (21.5%) patients had developed dementia. At the Cox regression analysis, dPSD was associated with cortical atrophy (hazard ratio [HR] = 3.4, 95% CI 1.5 to 7.9), age (HR = 3.3, 95% CI 1.4 to 7.8), and multiple ischemic lesions (HR = 2.5, 95% CI 1.2 to 4.8). The Kaplan-Meier analysis showed a significant difference between the incidence of dPSD subtypes (log-rank test; p = 0.002).

CONCLUSIONS

During the 4-year follow-up, the incidence of dementia increased gradually, shifting from an Alzheimer disease-type picture in the first years to a vascular dementia type later in years 2 to 4.

Discontinuous-flow plasmapheresis and patent foramen ovale: a possible cause of paradoxical embolism

A 68-year-old woman was admitted for a subacute polyradiculoneuropathy and submitted to PE. A central right jugular venous access was placed after the third PE procedure due to a failing peripheral blood access. During the fourth PE, performed with a discontinuous-flow system (continuous-flow used for 3 procedures), she developed multiple embolic ischemic lesions in the left middle cerebral artery (MCA) territory. A thorough cerebrovascular screening showed only a patent foramen ovale (PFO). In our case, a possible increase of the right atrium blood pressure induced by the positive flux of the discontinuous-flow PE could have been responsible for a paradoxical embolism through the PFO. Plasma exchange (PE) is used in several neurologic disorders. It is commonly thought to be a relatively safe procedure. However, a number of adverse events may occur: paradoxical embolism has not been reported to occur.

SPASE-I: a multicenter observational study on pharmacological treatment of acute stroke in the elderly. The Italian Study of Pharmacological Treatment of Acute Stroke in the Elderly Group

We investigated the clinical outcome and current therapeutic management of ischemic stroke in elderly patients in different neurological wards throughout Italy. Twelve centers in 10 Italian regions were involved. The clinical and instrumental data were prospectively collected for 335 patients 65 years or older, presenting in a 12-months period. At the multivariate analysis, death was associated with the presence of total anterior circulation infarct and the use of antiedema agents. Stroke-related disability was related to female sex, unified stroke scale (USS) scores at entry and mini-mental state examination (MMSE) scores at the 1-months follow-up. The majority of patients (70%) received antiplatelets to prevent stroke recurrence. Very elderly (> or =80 years) patients had worse presentation and prognosis than less elderly stroke victims (<80 years). Age played an important role in the therapeutic approach to stroke: while antiplatelets were widely used, oral anticoagulants were underused even when specifically indicated.

Vascular dementia: a cognitive SPET-CBF activation study

OBJECTIVE

We investigated the pattern of regional cerebral blood flow (rCBF) responses to a cognitive task in vascular patients with and without dementia.

METHOD

We studied 8 controls and 18 vascular patients by quantitative rCBF assessed by (133)Xe inhalation method and SPET, both at rest and during a cognitive figure recognition task. Eight were mildly demented and 10 were nondemented vascular patients. According to their task performance, 12 patients were classified as 'good performers' (GPs) and 6 patients as 'poor performers' (PPs).

RESULTS

Vascular patients activated a larger number of brain areas than controls. No differences were observed between controls, nondemented and mildly demented patients in the pattern of rCBF activation. GPs presented a lower mean percentage of rCBF increase than either controls or PPs. GPs had lower values than PPs in the left temporal, parietal and occipital regions and in the right posterior cingulate and occipital regions.

CONCLUSIONS

These data suggest that vascular patients may functionally compensate for vascular damage by activating more brain areas than controls do and, consequently, by increasing the rate of regional activation.

Usefulness of primitive reflexes in demented and non-demented cerebrovascular patients in daily clinical practice

The aim of this study was to investigate the usefulness of primitive reflexes (PRs) as additional alert signs in a routine clinical setting of cognitive decline in an elderly population of chronic ischemic cerebrovascular patients. We considered the occurrence of grasp, palmomental, glabellar and snout reflexes in 75 demented (VaD) and 75 non-demented (VaND) patients, and in 75 healthy elderly controls. We never elicited more than two PRs in controls. The occurrence of three or four PRs provided the strongest correlation with dementia (p < 0.0001), with 93% specificity irrespective of low sensitivity. In conclusion, the occurrence of more than two PRs might serve as an additional warning sign of possible mild cognitive impairment in chronic ischemic cerebrovascular patients.

Correlation between high-pass resolution perimetry and standard threshold perimetry in subjects with glaucoma and ocular hypertension

PURPOSE

To evaluate the correlation between High-Pass Resolution Perimetry (HRP) and standard threshold perimetry in patients with glaucoma or ocular hypertension.

METHODS

31 glaucomatous patients and 37 ocular hypertension subjects with previous perimetric examination experience were consecutively recruited and only one eye for each patient was selected at random. Glaucomatous patients were classified as having primary open angle glaucoma when they had an abnormal visual field and/or an abnormal optic nerve head (ONH)/retinal nerve fiber layer (RNFL) typical of glaucoma, open angle at gonioscopy and no clinically apparent secondary cause for their glaucoma. Ocular hypertension subjects were defined as having intraocular pressure >21 mm Hg on no treatment, normal visual field, normal ONH and RNFL, elevated intraocular pressure without any treatment. All the subjects were examined with Humphrey Field Analyzer (HFA) 640, 'program central 30-2' (Humphrey Systems, San Leandro, CA, USA) and with High-Pass Resolution Perimeter (HRP), Ophthimus version 2.4,'ring program' (Nikon-HighTech Vision, Goteborg, Sweden). Visual field indices were obtained with both systems: for HFA mean deviation (MD), corrected pattern standard deviation (CPSD) and short term fluctuation (SF), while for HRP global deviation (GD), local deviation (LD), form index (FI) and neural capacity (NC). The data were analyzed by descriptive analysis, Student's t test with Bonferroni's correction or Mann-Whitney non-parametric test and Pearson or Spearman's correlation coefficient.

RESULTS

A significant correlation was found between MD and GD (r = -0.81), CPSD and LD (r = 0.87), PSD and LD (r = 0.72). NC was significantly correlated with MD (r = 0.76), GD (r = -0.94). FI was significantly correlated with PSD (r = -0.58), CPSD (r = -0.72), LD (r = -0.56). When the same data were analyzed for the glaucomatous group only, similar results were found; in the ocular hypertensive group no significant correlation was found except between NC and MD (r = 0.52).

CONCLUSION

HRP indices vary comparably with HFA indices. Parameters as NC and FI were significantly correlated with standard visual field indices of both HFA and HRP. Although the clinical applications for FI are not clear yet, NC could detect both early glaucomatous damage and age related changes.

Comparison between relative dispersion analysis of high-pass resolution perimetry and standard threshold perimetry

PURPOSE

To evaluate the correlation of the dispersion index (DI) of relative dispersion analysis (RDA), a new high-pass resolution perimetry (HRP) index, with other HRP indices and those of the Humphrey standard threshold perimeter (STP) parameters.

METHODS

Sixty-eight eyes were randomly recruited. Thirty-one eyes were classified as glaucomatous (high intraocular pressure, abnormal visual field and/or optic disc) and 37 as ocular hypertensives (high intraocular pressure, normal visual field, normal optic disc). All the subjects were examined with Humphrey Perimeter, program 30-2, and HRP. The HRP data were also analysed with the RDA program. Statistical analysis was performed with Student's t-test, Pearson's r correlation coefficient, Mann-Whitney nonparametric test and Spearman correlation coefficient when appropriate.

RESULTS

Within the entire sample significant correlations were found between the RDA index (DI) and all the HRP indices (p < 0.001) and corrected pattern standard deviation (p < 0.01), pattern standard deviation (PSD) (p < 0.01), mean deviation (p < 0.05) and short-term fluctuation (p < 0.05) of STP. A stronger correlation was found in glaucomatous patients. In subjects with ocular hypertension DI was only weakly correlated with PSD, local deviation and form index. No difference in DI was found between glaucoma and ocular hypertension.

CONCLUSION

The DI of HRP has the theoretical capacity to detect localised inhomogeneity of retinal sensitivity, but at present our data do not support this hypothesis. Before any clinical applications of this index further studies are needed.

Do transient ischemic attacks have a neuroprotective effect?

OBJECTIVE

To determine whether TIAs have a neuroprotective effect.

BACKGROUND

Ischemic tolerance or preconditioning, which protects the brain against stroke, has been demonstrated in animal models of cerebral ischemia. Because TIA may represent a clinical model of ischemic tolerance, patients with TIA before cerebral infarction (CI) may therefore have a better outcome than patients without TIA before CI.

METHODS

A total of 2,490 patients admitted consecutively to a primary care center for first-ever CI in the anterior circulation were divided into two groups on the basis of the presence or absence of prior ipsilateral TIAs. Duration of TIA was classified into three groups (<10 minutes, 10 to 20 minutes, and >20 minutes). The severity of the neurologic picture on admission and functional disability after stroke were compared between patients with and without TIAs.

RESULTS

A total of 293 (12%) of the 2,490 patients had prior ipsilateral TIAs before CI. Risk factors did not differ between patients with or without TIAs, whereas the topography and etiology of ischemic stroke did differ (p < 0.001). Patients without prior TIAs had a more severe clinical picture on admission, with a greater reduction of consciousness (p = 0.009). Patients with previous TIAs had a more favorable outcome than those without TIAs (67% versus 58%, p = 0.004). After adjustment for confounding variables, TIAs lasting 10 to 20 minutes were still associated with a favorable outcome (odds ratio, 1.98; 95% confidence interval, 1.27 to 3.08; p = 0.002). The interval between TIA and CI influenced the outcome (p = 0.007).

CONCLUSIONS

This study suggests that ischemic tolerance may play a role in patients with ipsilateral TIAs before CI, allowing better recovery from a subsequent ischemic stroke.

Bromocriptine and speech therapy in non-fluent chronic aphasia after stroke

The objectives of this study were to investigate the efficacy of bromocriptine (BR) combined with speech therapy (ST) to improve a late recovery in non-fluent aphasic stroke patients. We performed a double-blind study with high dosage of BR, prescribed according to a dose-escalating protocol, comprehensive of clinical data, relatives' impression, and language evaluations. The study was divided into the following phases: t-0, inclusion; t-30, language re-test to evaluate the stability of aphasia; t-90, placebo (PL) and ST; t-150, BR and ST; t-210, BR; t-270, wash-out. With respect to the baseline assessment, a significant improvement was observed in the following tests: dictation (F, 4.8; p < .004), reading-comprehension (F, 8.1; p < .0003), repetition (F, 3.8; p < .01) and verbal latency (F, 4.9; p < .01). High dosage of BR promoted a late recovery in stable chronic non-fluent aphasia and this improvement was enhanced by combination with ST.

Multiple brain infarcts: clinical and neuroimaging patterns using diffusion-weighted magnetic resonance

The capability of diffusion-weighted (DW) magnetic resonance imaging (MRI) to identify very early ischemic brain injury better than conventional MRI is well known. This technique, which successfully discriminates acute from old infarcts, is particularly useful in patients with multiple brain infarcts (MBI). Among 142 patients with acute stroke consecutively admitted to our primary care center, we selected 43 patients with two or more brain infarcts on conventional MRI. All patients presented with clinical deficits consistent with acute cerebral ischemia and underwent conventional spin echo for T(1) (T1-WI) and T(2)-weighted images (T2-WI), T(1)-W gadolinium-enhanced images, and echo-planar technique for DW MRI sequences. Patients underwent DW MRI examinations within 15 days of stroke onset (mean +/- SD: 3 +/- 3 days). In all but 1 case, the infarcts detected on DW MRI were also visible on T2-WI. The different signal pattern on DW MRI, compared with T2-WI, facilitated the detection of acute infarcts in all patients. T1-WI with gadolinium enhancement was only helpful in 5 (11.6%) patients. DW MRI enabled precise clinicotopographic correlations in 79% of our patients and provided additional clinically relevant findings in 72% of the patients. Based on the neuroradiological findings, patients were divided into three clinicotopographic types of MBI as follows: 13 patients (30.2%) presented with multiple acute infarcts, 24 patients (55.8%) with a single acute infarct and multiple old infarcts, and 6 patients (13.9%) with multiple acute and old infarcts. In conclusion, DW MRI can easily be added to conventional MRI in order to be able to distinguish acute from old infarcts, and to identify acute multiple lesions. Therefore, a better correlation between clinical symptoms and the site of lesions can be obtained, considerably improving patient care.

Large-scale identification of virulence genes from Streptococcus pneumoniae

Streptococcus pneumoniae is the major cause of bacterial pneumonia, and it is also responsible for otitis media and meningitis in children. Apart from the capsule, the virulence factors of this pathogen are not completely understood. Recent technical advances in the field of bacterial pathogenesis (in vivo expression technology and signature-tagged mutagenesis [STM]) have allowed a large-scale identification of virulence genes. We have adapted to S. pneumoniae the STM technique, originally used for the discovery of Salmonella genes involved in pathogenicity. A library of pneumococcal chromosomal fragments (400 to 600 bp) was constructed in a suicide plasmid vector carrying unique DNA sequence tags and a chloramphenicol resistance marker. The recent clinical isolate G54 was transformed with this library. Chloramphenicol-resistant mutants were obtained by homologous recombination, resulting in genes inactivated by insertion of the suicide vector carrying a unique tag. In a mouse pneumonia model, 1.250 candidate clones were screened; 200 of these were not recovered from the lungs were therefore considered virulence-attenuated mutants. The regions flanking the chloramphenicol gene of the attenuated mutants were amplified by inverse PCR and sequenced. The sequence analysis showed that the 200 mutants had insertions in 126 different genes that could be grouped in six classes: (i) known pneumococcal virulence genes; (ii) genes involved in metabolic pathways; (iii) genes encoding proteases; (iv) genes coding for ATP binding cassette transporters; (v) genes encoding proteins involved in DNA recombination/repair; and (vi) DNA sequences that showed similarity to hypothetical genes with unknown function. To evaluate the virulence attenuation for each mutant, all 126 clones were individually analyzed in a mouse septicemia model. Not all mutants selected in the pneumonia model were confirmed in septicemia, thus indicating the existence of virulence factors specific for pneumonia.

Induction of insulitis by glutamic acid decarboxylase peptide-specific and HLA-DQ8-restricted CD4(+) T cells from human DQ transgenic mice

Insulin-dependent diabetes mellitus in humans is linked with specific HLA class II genes, e.g., HLA-DQA1*0301/ DQB1*0302 (DQ8). To investigate the roles of HLA-DQ8 molecules and glutamic acid decarboxylase (GAD) in disease development, we generated DQ8(+)/I-Abo transgenic mice expressing functional HLA-DQ8 molecules and devoid of endogenous mouse class II. DQ8(+)/I-Abo mice produced antigen-specific antibodies and formed germinal centers after immunization with GAD65 peptides. Two GAD peptide-specific (247-266 and 509-528), DQ8 restricted Th1 CD4(+) T cell lines, were generated from immunized DQ8(+)/I-Abo mice. They induced severe insulitis after adoptive transfer into transgene positive (but not negative) mice who were treated with a very low dose of streptozotocin that alone caused no apparent islet pathology. In addition to CD4, islet mRNA from these mice also showed expression of CD8, IFNgamma, TNFalpha, Fas, and Fas ligand. Our data suggest that a mild islet insult in the presence of HLA-DQ8 bearing antigen-presenting cells promotes infiltration of GAD peptide reactive T cells into the islet.

RA/DA cumulative curve analysis of local and diffuse neuroretinal rim area damage in glaucoma patients

AIM

To evaluate the validity of cumulative rim/disc area (RA/DA) curve analysis as a clinical tool for the identification of glaucoma induced optic disc pathology.

METHODS

71 normal and 83 glaucomatous eyes were evaluated from a series of 154 subjects recruited for this study. For each eye, the cumulative distribution of RA/DA was calculated from 36 equally spaced rim sectors of each optic disc obtained by the automatic evaluation of simultaneous videographics (Image-net X Rev.3/51b). To increase the sensitivity of this analysis in early glaucoma and in normal eyes, these cumulative curves were subsequently divided into two equal segments and the slopes of their respective regression lines compared.

RESULTS

The median RA/DA value obtained from the 36 sectors was significantly different in glaucomatous eyes compared with normals (p < 0.001). Nevertheless, the curves (5th-95th percentile of the cumulative curves distribution) of early glaucomatous eyes fell within the normal range. When the cumulative curve of these marginal cases was then divided into two equal segments, the comparison of the slopes of the regression lines showed a significant difference (p < 0.05) in 100% of early glaucomatous eyes. Furthermore, normal eyes were shown to be true negatives in 93% of the cases in which no significant difference between the two slopes was observed.

CONCLUSION

Analysis of the RA/DA cumulative curve from 36 sectors of the optic disc was a valid method for the identification of glaucomatous disc pathology; however, a further calculation of the slopes of the two RA/DA regression lines was needed to identify early glaucomatous damage.

GAD-reactive CD4+ Th1 cells induce diabetes in NOD/SCID mice

Although glutamic acid decarboxylase (GAD) has been implicated in IDDM, there is no direct evidence showing GAD-reactive T cells are diabetogenic in vivo. To address this issue, 3-wk-old NOD mice received two injections of purified rat brain GAD; one mouse rapidly developed diabetes 3 wk later. Splenocytes from this mouse showed a proliferative response to purified GAD, and were used to generate a CD4+ T cell line, designated 5A, that expresses TCRs encoding Vbeta2 and Vbeta12. 5A T cells exhibit a MHC restricted proliferative response to purified GAD, as well as GAD65 peptide 524-543. After antigen-specific stimulation, 5A T cells secrete IFNgamma and TNFalpha/beta, but not IL-4. They are also cytotoxic against NOD-derived hybridoma cells (expressing I-Ag7) that were transfected with rat GAD65, but not nontransfected hybridoma cells. Adoptive transfer of 5A cells into NOD/SCID mice produced insulitis in all mice. Diabetes occurred in 83% of the mice. We conclude that GAD injection in young NOD mice may, in some cases, provoke diabetes due to the activation of diabetogenic T cells reactive to GAD65 peptides. Our data provide direct evidence that GAD65 autoimmunity may be a critical event in the pathogenesis of IDDM.

[Brain dysfunction in climacteric and prevention]

The risk of cardiovascular disease in women is relatively small before menopause but increases considerably afterwards. Postmenopausal women have on average a total cholesterol, LDL and VLDL cholesterol levels higher than premenopausal women; at the same time, HDL cholesterol serum level is lower. Postmenopausal estrogen replacement therapy (ERT) has been repeatedly proven to reduce the incidence of coronary heart disease as well as the mortality from cardiovascular disease. Furthermore, little is known about the potential risk of developing a stroke associated to hormonal changes involved in the menopause. Likewise the benefit of the ERT on reduction in stroke-legated mortality and morbidity is still debated. On the other hand, preliminary trials suggest a beneficial role of ERT in women with Alzheimer's disease (AD), probably due to the estrogen's cholinergic neurotrophic and neuroprotective effects. Moreover, recent reports suggest a possible additive beneficial effect of ERT to cholinergic treatments for AD In normal postmenopausal women the ERT not only improve cognitive and emotional functions but also increase verbal memory.