Susceptibility to gut leakiness: a possible mechanism for endotoxaemia in non‐alcoholic steatohepatitis

Introduction: One of the proposed second hit mechanisms in the pathophysiology of non‐alcoholic steatohepatitis (NASH) is hepatic oxidative stress triggered by elevated levels of endotoxin. We investigated one possible mechanism for the endotoxaemia – disruption of intestinal barrier integrity. Methods: We enrolled 16 subjects with fatty liver (10 NASH; 6 steatosis) and 12 healthy subjects. Steatosis and NASH were diagnosed by liver biopsy using the Brunt criteria. Gastrointestinal permeability was measured using urinary excretion of 5‐h lactulose/mannitol (L/M) ratio and 24‐h sucralose. Permeability testing was repeated after aspirin challenge. Results: Groups had similar baseline urinary 0–5 h L/M ratio (small bowel permeability) and 0–24 h sucralose (whole‐gut permeability). Aspirin increased 0–5 h urinary L/M in most subjects. In contrast, aspirin significantly increased whole‐gut permeability only in NASH subjects. In fact, the major increase in the urinary sucralose occurred in the 6–24 h samples, which points towards the colon as the major site responsible for aspirin‐induced leakiness in NASH patients. Serum endotoxin levels were significantly higher in NASH subjects. Discussion: Our findings suggest that aspirin acts on the colon to unmask a susceptibility to gut leakiness in patients with NASH. This effect may be the underlying mechanism for increased serum endotoxin, which is the second hit (after altered lipid metabolism) that is required to initiate a necroinflammatory cascade in hepatocytes which are already primed with obesity‐induced abnormal lipid homoeostasis.     

Neurosurgery of epilepsy,movement disorders and pain

Functional neurosurgery involves the surgical management of a wide range of neurological diseases with the aim of treating conditions such as movement disorders, spasticity, epilepsy and intractable pain. Functional neurosurgery began with ablative surgical techniques involving destruction of neural structures responsible for the aberrant neural pathways/networks causing pathology. In more recent years there has been a move away from the creation of permanent destructive lesions towards modulation of the neural networks utilizing neuromodulation. Neuromodulation therapies include invasive (e.g. deep brain stimulators, cortical stimulators, vagal nerve stimulators and spinal cord stimulators) and non-invasive (e.g. transcranial magnetic stimulation) approaches that involve the application of electrical stimulation to drive or inhibit neural function within a circuit. Most implantable neuromodulation systems include three primary components: stimulating electrode(s) with contacts at the tip through which electricity is delivered; an implantable pulse generator (IPG) that serves as a signal generator/battery pack; and the extension cable(s) to subcutaneously connect the electrode(s) to the IPG. In this article we primarily focus on the current role of neuromodulation in treating movement disorders, epilepsy and pain, and also consider emerging and evolving applications.     

Single-port-access (SPATM) cholecystectomy: a multi-institutional report of the first 297 cases

Background

An important aspect of a new surgical technique is whether it can be performed by other surgeons in other institutions. The authors report the first 297 cases in a multi-institutional and multinational review of laparoscopic cholecystectomy performed via a single portal of entry.

Methods

Data were collected retrospectively for the initial patients undergoing single-port cholecystectomy by 13 surgeons who performed these procedures in their institutions after training by the authors. The review included operative time, blood loss, incision length, length of hospital stay (LOS), necessary additional trocars, and other parameters important to cholecystectomy. A database of all the single-port-access (SPA) surgeries performed by the surgeons included demographic and procedural details, LOS, complications, and initial follow-up data.

Results

To date, 297 single-port cholecystectomies have been performed for a variety of diagnoses, primarily cholelithiasis. The average operative time was 71 min, and the average LOS was 1–2 days. The average blood loss was minimal. The use of additional port sites outside the umbilicus occurred in 34 of the cases. Of the 35 intraoperative cholangiograms performed, 34 were successful. No significant complications occurred except for seromas and minor postoperative wound infections. These results are comparable with those for standard multiport cholecystectomy. In addition, no access site hernias (ASH) occurred.

Conclusions

The findings demonstrate that SPA surgery is an alternative to multiport laparoscopy with fewer scars and better cosmesis. One factor affecting the rate for adoption of SPA surgery among other surgeons is the reproducibility of this new procedure. Although this study had insufficient data to determine fully the benefits of SPA surgery, the feasibility of this procedure with safe, acceptable results was demonstrated in this initial large series across multinational institutions.     

Wilson's disease

Progressive hepatolenticular degeneration, or Wilson's disease, is a genetic disorder of copper metabolism. Knowledge of the clinical presentations and treatment of the disease are important both to the generalist and to specialists in gastroenterology and hepatology, neurology, psychiatry, and paediatrics. Wilson's disease invariably results in severe disability and death if untreated. The diagnosis is easily overlooked but if discovered early, effective treatments are available that will prevent or reverse many manifestations of this disorder. Studies have identified the role of copper in disease pathogenesis and clinical, biochemical, and genetic markers that can be useful in diagnosis. There are several chelating agents and zinc salts for medical therapy. Liver transplantation corrects the underlying pathophysiology and can be lifesaving. The discovery of the Wilson's disease gene has opened up a new molecular diagnostic approach, and could form the basis of future gene therapy.     

Left ventricular structure and function in patients with rheumatoid arthritis,as assessed by cardiac magnetic resonance imaging

Objective

Heart failure is a major contributor to cardiovascular morbidity and mortality in patients with rheumatoid arthritis (RA), but little is known about myocardial structure and function in this population. This study was undertaken to assess the factors associated with progression to heart failure in patients with RA.

Methods

With the use of cardiac magnetic resonance imaging, measures of myocardial structure and function were assessed in men and women with RA enrolled in the Evaluation of Subclinical Cardiovascular Disease and Predictors of Events in Rheumatoid Arthritis study, a cohort study of subclinical cardiovascular disease in patients with RA, in comparison with non‐RA control subjects from a cohort enrolled in the Baltimore Multi‐Ethnic Study of Atherosclerosis.

Results

Measures of myocardial structure and function were compared between 75 patients with RA and 225 frequency‐matched controls. After adjustment for confounders, the mean left ventricular mass was found to be 26 gm lower in patients with RA compared with controls (P < 0.001), an 18% difference. In addition, the mean left ventricular ejection fraction, cardiac output, and stroke volume were modestly lower in the RA group compared with controls. The mean left ventricular end systolic and end diastolic volumes did not differ between the groups. In patients with RA, higher levels of anti–cyclic citrullinated peptide (anti‐CCP) antibodies and current use of biologic agents, but not other measures of disease activity or severity, were associated with significantly lower adjusted mean values for the left ventricular mass, end diastolic volume, and stroke volume, but not with ejection fraction. The combined associations of anti‐CCP antibody level and biologic agent use with myocardial measures were additive, without evidence of interaction.

Conclusion

These findings suggest that the progression to heart failure in RA may occur through reduced myocardial mass rather than hypertrophy. Both modifiable and nonmodifiable factors may contribute to lower levels of left ventricular mass and volume.

     

Amplitude modulation of oscillatory activity in the subthalamic nucleus during movement

Depth recordings in patients with Parkinson's disease (PD) have demonstrated exaggerated local field potential (LFP) activity at frequencies between 10 and 30 Hz in the subthalamic nucleus (STN). This activity is modulated prior to single phasic movements, possibly as part of the feedforward organization of incipient voluntary movement, and after single phasic movements, as a consequence of afferent feedback processes. Here we test the hypothesis that this activity is also modulated during repetitive movements, reflecting a role in ongoing performance. Accordingly, we recorded LFP activity from the contralateral STN of seven patients with PD withdrawn from anti-parkinsonian medication while they performed repetitive index finger to thumb taps. Cross-correlograms of LFP activity at different frequencies in the 10–30 Hz band with finger position showed that LFP activity was modulated in amplitude by finger tapping. The modulation was higher at the beginning of each recording when tapping performance was better, and diminished as tapping became more bradykinetic over time. The best modulations were seen over those frequencies that were maximal in the power spectrum of the corresponding LFP, and for a given side were most marked at the contact pair that exhibited the highest power at these frequencies. In conclusion, subthalamic activity in the 10–30-Hz band is amplitude modulated during movement. This process fails as bradykinesia increases.