Proposed Mayo Clinic criteria for the diagnosis of Tako-Tsubo cardiomyopathy and long-term prognosis

Tako-Tsubo cardiomyopathy (TTC) is a reversible cardiomyopathy with a clinical presentation indistinguishable from myocardial infarction. TTC is estimated to represent 1%-2% of patients presenting with acute myocardial infarction. It most commonly occurs in postmenopausal women and is frequently precipitated by a stressful event. Chest pain and dyspnea are the typical presenting symptoms. Transient ST-segment elevation on ECG and a small rise in cardiac biomarkers are common. Characteristic wall motion abnormalities extend beyond the territory of a single epicardial coronary artery in the absence of obstructive coronary lesions. Supportive treatment leads to spontaneous rapid recovery in nearly all patients. The prognosis is excellent, and recurrence occurs in < 10% of patients. In this article, we review the clinical features of TTC that form the basis of the Mayo Clinic diagnostic criteria, as well as the long-term prognosis for this type of cardiomyopathy.

Distinguishing dynamics using recurrence-time statistics

The probability densities of the mean recurrence time, which is the average time needed for a system to recur to a previously visited neighborhood, are investigated in various dynamical regimes and are found to be in agreement with those of the finite-time Lyapunov exponents. The important advantages of the former ones are that they are easy to estimate and that comparable short time series are sufficient. Asymmetric distributions with exponential tails are observed for intermittency and crisis-induced intermittency, while for typical chaos, the distribution has a Gaussian shape. Further, the shape of the distribution distinguishes intermittent strange nonchaotic attractors from those appearing through fractalization and tori collision mechanisms. Furthermore, statistics performed on the peaks in the frequency distribution of recurrence times unveil scaling behavior in agreement with that obtained from the spectral distribution function defined as the number of peaks in the Fourier spectrum greater than a predefined value. The results of the present recurrence statistics are of relevance in classifying different dynamics and providing important insights into the dynamics of a system when only one realization of this system is available. The practical use of this approach for experimental data is shown on experimental electrochemical time series.

Homocystinuria: Challenges in diagnosis and management

Two patients with homocystinuria are discussed. Both patients presented with behavioural abnormalities and deficits in attention - symptoms that are frequently encountered in paediatric office practice. In both cases, the diagnosis of homocystinuria was not made at initial presentation. Subtle but definite phenotypic features eventually provided the first indication of homocystinuria between the ages of five to seven years. Laboratory screening confirmed homocystine in the urine, and elevated methionine and homocysteine plasma levels in both patients. Patients with inborn errors of metabolism such as homocystinuria are treated first by family physicians and paediatricians. Without a high index of suspicion, physicians can easily overlook a diagnosis of homocystinuria. The management of patients with homocystinuria continues to pose a challenge to physicians and care givers.

In situ observation of size-scale effects on the mechanical properties of ZnO nanowires

In this investigation, the size-scale in mechanical properties of individual [0001] ZnO nanowires and the correlation with atomic-scale arrangements were explored via in situ high-resolution transmission electron microscopy (TEM) equipped with atomic force microscopy (AFM) and nanoindentation (NI) systems. The Young's modulus was determined to be size-scale-dependent for nanowires with diameter, d, in the range of 40 nm ≤ d ≤ 110 nm, and reached the maximum of ∼ 249 GPa for d = 40 nm. However, this phenomenon was not observed for nanowires in the range of 200 nm ≤ d ≤ 400 nm, where an average constant Young's modulus of ∼ 147.3 GPa was detected, close to the modulus value of bulk ZnO. A size-scale dependence in the failure of nanowires was also observed. The thick ZnO nanowires (d ≥ 200 nm) were brittle, while the thin nanowires (d ≤ 110 nm) were highly flexible. The diameter effect and enhanced Young's modulus observed in thin ZnO nanowires are due to the combined effects of surface relaxation and long-range interactions present in ionic crystals, which leads to much stiffer surfaces than bulk wires. The brittle failure in thicker ZnO wires was initiated from the outermost layer, where the maximum tensile stress operates and propagates along the (0001) planes. After a number of loading and unloading cycles, the highly compressed region of the thinner nanowires was transformed from a crystalline to an amorphous phase, and the region near the neutral zone was converted into a mixture of disordered atomic planes and bent lattice fringes as revealed by high-resolution images.

Efficacy, safety and tolerability of duloxetine in idiopathic trigeminal neuralgia

Trigeminal neuralgia (TN) is the most common type of neuralgia affecting facial region and is considered to be one of the most painful conditions. Treatment is often unsatisfactory. Newer treatment modalities are therefore being tried. Duloxetine is FDA approved drug for painful diabetic neuropathy and has been used in painful symptoms of depression as well. Safety and efficacy of duloxetine was evaluated in patients with trigeminal neuralgia; another chronically painful condition, in an open label manner. A total of 15 patients who fulfilled the diagnostic criteria of International Headache Society for Trigeminal Neuralgia were administered duloxetine 40 mg daily. The efficacy of the drug was evaluated by face scale and Likert's numerical scale. Statistically significant pain relief was reported in 9 out of 15 patients of trigeminal neuralgia. The pain relief was reported as early as in one week and was maintained for 16 weeks. The drug was well tolerated and side-effects reported were mild and reversible. No adverse drug reaction requiring hospitalisation or drug discontinuation was reported in the present study. Duloxetine showed statistically significant pain relief in trigeminal neuralgia. Double-blind, placebo-controlled studies are needed to confirm findings at a large scale.

Postoperative pain after cholecystectomy: Conventional laparoscopy versus single-incision laparoscopic surgery

BACKGROUND

This study was undertaken to compare the postoperative pain after cholecystectomy done by single-incision laparoscopic surgery (SILS) versus conventional four-port laparoscopy [conventional laparoscopic surgery (CLS)]. SILS is a feasible and a promising method for cholecystectomy. It is possible to do this procedure without the use of special equipments. While there are cosmetic advantages to SILS, it is not clear whether or not the pain is also reduced.

METHODS

Patients undergoing cholecystectomy for symptomatic gallstones were offered the choice of the two methods and the first 100 consecutive patients from each group were included in this observational study. Only conventional instruments were used to keep the cost of surgery comparable. Pain scores were checked 8 hours after the surgery using visual analogue score. Student's t test was done to check the statistical significance.

RESULTS

We observed no significant difference in the pain score between the CLS and SILS (2.78 versus 2.62). The operative time (OT) was significantly lower in the CLS group (28 versus 67 minutes). Comparing the OTs of the first 50 patients undergoing SILS with the second 50 patients showed a significantly lower OT (79 versus 54 minutes). We also compared the pain score between these three groups. The second half of SILS group had a significantly lower pain score compared to the first half (2.58 versus 2.84). This group also had a lower pain score compared to conventional laparoscopy group but the difference was not statistically significant (2.58 versus 2.78).

CONCLUSION

Although there was no significant difference in the overall postoperative pain as OT decreases with surgeon's experience in single-incision laparoscopic cholecystectomy, postoperative pain at 8 hours appears to favour this method over conventional laparoscopic cholecystectomy.

Hemizygous deletions on chromosome 1p21.3 involving the DPYD gene in individuals with autism spectrum disorder

We describe the identification and clinical presentation of four individuals from three unrelated families with hemizygous deletions involving the DPYD gene at chromosome 1p21.3. DPYD encodes dihydropyrimidine dehydrogenase, which is the initial and rate-limiting enzyme in the catabolism of pyrimidine bases. All four individuals described met diagnostic criteria for autism spectrum disorder with severe speech delay. Patient 1's deletion was originally reported in 2008, and more detailed clinical information is provided. Subsequently, this male individual was found to have a missense mutation in the X-linked PTCHD1 autism susceptibility gene, which may also contribute to the phenotype. Patients 2 and 3 are siblings with a novel deletion encompassing the DPYD gene. In their mother, the genomic region deleted from chromosome 1p21.3 was inserted into chromosome 10. A fourth proband had a novel 10-kb intragenic deletion of exon 6 of the DPYD gene detected on a higher resolution microarray. Our study suggests that hemizygous deletions involving the DPYD locus present with variable phenotypes which can include speech delay and autistic features, and may also be influenced by additional mutations in other genes, issues which need to be considered in genetic counseling.

Multi detector computed tomography (MDCT) evaluation of small bowel obstruction: pictorial review

Small bowel obstruction (SBO) is one of the most perplexing clinical situations encountered by a surgeon in the emergency room. The decision to operate or not depends upon many factors including the probable cause and chances of bowel strangulation/ischemia. The clinical, biochemical and radiological features help the surgeon in making this decision. Plain X-rays have been the mainstay in the radiological diagnosis of SBO and its complications. In the last 20 years, CT scan has ushered in a revolution in establishing the diagnosis of SBO, its causes and complications earlier than the traditional methods and has helped in reducing morbidity and mortality. Here, we have summarised the role of multidetector CT scan in diagnosing various aspects of SBO.