Tuberculous mastitis–A great mimicker

ObjectiveTo focus on the increasing incidence of breast tuberculosis, its mistaken identity with carcinoma or pyogenic abscess and its effective diagnosis on cytology.MethodsThis retrospective study was carried over short period of two months. Six patients were included. air dried and wet fixed smears prepared and stained with May-Grunwwald-Giemsa and Papanicolaou respectively. Zeihl Neelson staining was also applied.ResultsAge groups varied from 16 to 70 years. Six cases presented within 2 months. Most common presentation was painless lump breast. One patient presented with discharging sinus. Lumps mostly favored right breast with predominance of upper outer quadrant. All except one were found to be positive for AFB.ConclusionsIncidences of tuberculous mastitis are increasing, can mimic carcinoma or abscess and should always be kept in differential diagnosis of lump breast. FNAC is helpful and ZN staining is gold standard in diagnosing acid fast bacilli.     

Hepatic abscess induced by foreign body： Case report and literature review

Hepatic abscess due to perforation of the gastrointestinal tract caused by ingested foreign bodies is uncommon. Pre-operative diagnosis is difficult as patients are often unaware of the foreign body ingestion and symptoms and imagiology are usually non-specific. The authors report a case of 62-year-old woman who was admitted with fever and abdominal pain. Further investigation revealed hepatic abscess, without resolution despite antibiotic therapy. A liver abscess resulting from perforation and intra-hepatic migration of a bone coming from the pilorum was diagnosed by surgery. The literature concerning foreign body-induced perforation of the gastrointestinal tract complicated by liver abscess is reviewed.     

The stomach–brain axis

The stomach has distinct functions in relation to the ingestion and handling of solids and liquids. These functions include storage of the food before it is gradually emptied into the duodenum, mechanical crushing of larger food particles to increase the surface area, secretion of an acidic enzyme rich gastric juice and mixing the ingested food with the gastric juice. In addition, the stomach ‘senses’ the composition of the gastric content and this information is passed via the vagal nerve to the lateral hypothalamus and the limbic system, most likely as palatability signals that influence eating behaviour. Other sensory qualities related to the stimulation of gastric tension receptors are satiety and fullness. Receptors that respond to macronutrient content or gastric wall tension influence appetite and meal related hormone responses.The ingestion of food – in contrast to an infusion of nutrients into the stomach – has distinct effects on the activation of specific brain regions. Brain areas such as thalamus, amygdala, putamen and praecuneus are activated by the ingestion of food. Gastric nutrient infusion evokes greater activation in the hippocampus and anterior cingulate. The brain integrates these interrelated neural and hormonal signals arising from the stomach as well as visual, olfactory and anticipatory stimuli that ultimately influence eating and other behavioural patterns. Furthermore, there is now good evidence from experimental studies that gastric afferents influence mood, and animal studies point towards the possibility that gastric dysfunction may be a risk factor for mood disorders such as anxiety and depression. The stomach is also not only colonised by Helicobacter pylori but a large array of bacteria. While there is sufficient evidence to suggest that H. pylori may alter caloric intake and mood, the role of other gastric microbiome for the brain function is unknown. To address this appropriate targeted gastric microbiome studies would be required instead of widely utilised opportunistic stool microbiome studies.In summary, it is now well established that there are important links between the brain and the stomach that have significant effects on gastric function. However, the stomach also influences the brain. Disturbances in the crosstalk between the stomach and the brain may manifest as functional GI disorders while disturbances in the stomach–brain communication may also result in an altered regulation of satiety and as a consequence may affect eating behaviour and mood. These observations may enable the identification of novel therapies targeted at the gastroduodenum that positively alter brain function and treat or prevent conditions such as obesity or functional gastrointestinal disorders.     

The gut–brain axis in obesity

Currently the only effective treatment for morbid obesity with a proven mortality benefit is surgical intervention. The underlying mechanisms of these surgical techniques are unclear, but alterations in circulating gut hormone levels have been demonstrated to be at least one contributing factor. Gut hormones seem to communicate information from the gastrointestinal tract to the regulatory appetite centres within the central nervous system (CNS) via the so-called 'Gut-Brain-Axis'. Such information may be transferred to the CNS either via vagal or non-vagal afferent nerve signalling or directly via blood circulation. Complex neural networks, distributed throughout the forebrain and brainstem, are in control of feeding and energy homoeostasis.This article aims to review how appetite is potentially regulated by these gastrointestinal hormones. Identification of the underlying mechanisms of appetite and weight control may pave the way to develop better surgical techniques and new therapies in the future.     

Exercise influence on the microbiome–gut–brain axis

ABSTRACT

The microbiome in the gut is a diverse environment, housing the majority of our bacterial microbes. This microecosystem has a symbiotic relationship with the surrounding multicellular organism, and a balance and diversity of specific phyla of bacteria support general health. When gut bacteria diversity diminishes, there are systemic consequences, such as gastrointestinal and psychological distress. This pathway of communication is known as the microbiome–gut–brain axis. Interventions such as probiotic supplementation that influence microbiome also improve both gut and brain disorders. Recent evidence suggests that aerobic exercise improves the diversity and abundance of genera from the Firmcutes phylum, which may be the link between the positive effects of exercise on the gut and brain. The purpose of this review is to explain the complex communication pathway of the microbiome–gut–brain axis and further examine the role of exercise on influencing this communication highway.     

Splenic abscess due to Brucella infection: is the splenectomy necessary? Case report and literature review

The case of a woman with splenic abscess due to Brucella is reported. There was no response with antibiotics and surgical treatment was required. On the basis of this case and the literature review we consider that surgical treatment must be considered in patients with splenic abscess due to Brucella infection.     

Dorfman–Chanarin Syndrome: A Case Report

An 8-year-old male child, diagnosed case of congenital ichthyosis presented with abdominal distension, hepatomegaly and pancytopenia. His peripheral blood and bone marrow showed clear punched out intracytoplasmic vacuolations in leucocytes (Jordans’ anomaly). He had convergent strabismus, ectropion, blepharitis and genu valgum. He was diagnosed as a case of Dorfman–Chanarin syndrome.     

High-speed spelling with a noninvasive brain–computer interface

The past 20 years have witnessed unprecedented progress in brain–computer interfaces (BCIs). However, low communication rates remain key obstacles to BCI-based communication in humans. This study presents an electroencephalogram-based BCI speller that can achieve information transfer rates (ITRs) up to 5.32 bits per second, the highest ITRs reported in BCI spellers using either noninvasive or invasive methods. Based on extremely high consistency of frequency and phase observed between visual flickering signals and the elicited single-trial steady-state visual evoked potentials, this study developed a synchronous modulation and demodulation paradigm to implement the speller. Specifically, this study proposed a new joint frequency-phase modulation method to tag 40 characters with 0.5-s-long flickering signals and developed a user-specific target identification algorithm using individual calibration data. The speller achieved high ITRs in online spelling tasks. This study demonstrates that BCIs can provide a truly naturalistic high-speed communication channel using noninvasively recorded brain activities.Brain–computer interfaces (BCIs), which can provide a new communication channel to humans, have received increasing attention in recent years (1, 2). Among various applications, BCI spellers (3–9) are especially valuable because they can help patients with severe motor disabilities (e.g., amyotrophic lateral sclerosis, stroke, and spinal cord injury) communicate with other people. Currently, electroencephalogram (EEG) is the most popular method of implementing BCI spellers due to its noninvasiveness, simple operation, and relatively low cost. However, low signal-to-noise ratio (SNR) of the scalp-recorded EEG signals and lack of computationally efficient solutions in EEG modeling limit the information transfer rates (ITRs) of EEG-based BCI spellers to ∼1.0 bits per second (bps) (1, 4). For example, the well-known P300 speller proposed by Farwell and Donchin (5) can spell up to five letters per minute (∼0.5 bps). Until recently few studies using visual evoked potentials (VEPs) demonstrated higher ITRs of 1.7–2.4 bps (6, 7). In contrast, the invasive BCI spellers in humans and monkeys show higher performance. For example, the P300 speller with electrocorticogram recordings obtained a peak ITR of 1.9 bps in a human subject (8). A recent monkey study on keyboard neural prosthesis using multineuron recordings reported an ITR up to 3.5 bps (9). Although communication speed of the EEG-based spellers has been significantly improved in the past decade (4), it still remains a key obstacle to real-life applications in humans.Recently, the BCI speller using steady-state VEPs (SSVEPs) has attracted increasing attention due to its high communication rate and little user training (4, 10, 11). An SSVEP speller typically uses SSVEPs to detect the user’s gaze direction to a target character (10). Although the SSVEP speller has achieved relatively high ITRs (e.g., 1.7 bps in ref. 6), the ultimate performance limit still remains unknown. In principle, the theoretical performance limit of the SSVEP speller highly depends on temporal coding precision in the visual pathway, which can be reflected by visual latency in SSVEPs [i.e., apparent latency (12)]. Previous studies show that grand-average SSVEPs can accurately encode the frequency and phase of the stimulation signals, showing a constant latency across different stimulation frequencies (12). However, visual latencies in single-trial SSVEPs, especially when the stimulation duration is short (e.g., 0.5 s), are generally difficult to quantify due to the interference from spontaneous EEG activities. Here we hypothesize that the visual latency of single-trial SSVEPs, which represent activities of neuronal populations over the stimulation time, can be very stable across trials. If this is true, frequency and phase of the stimulation signals can be precisely encoded in single-trial SSVEPs. Much better performance can be expected in the SSVEP speller using a synchronous modulation and demodulation paradigm, which has been widely used in telecommunications (13).The goal of this study is to implement a high-speed BCI speller using SSVEPs. Based on the assumption of a stable visual latency in single-trial SSVEPs, this study proposed a new joint frequency-phase modulation (JFPM) method to enhance the discriminability between SSVEPs with a very narrow frequency range, the most challenging conditions in frequency coding (10). To address the difficulty in parameter selection due to nonlinearity [i.e., SSVEP harmonics (14)], a data-driven grid-search method was developed to optimize stimulation duration and phase interval in the JFPM method. Considering individual difference of visual latency in target identification, this study adopted an improved user-specific decoding algorithm that incorporated individual SSVEP calibration data in feature extraction. In addition, a filter bank analysis method was developed to extract additional features from the harmonic SSVEP components. Together, these methods resulted in a high-speed BCI speller (up to 60 characters per minute) in multiple online spelling tasks. The methodological framework of the proposed high-speed BCI technology will potentially lead to a truly practical and naturalistic high-speed communication channel for patients with motor disabilities and healthy people.     

Case Report: Fatal Co-Infection–Melioidosis and Leptospirosis

Co-infection of melioidosis and leptospirosis is uncommon. We report here four such cases, confirmed by blood culture for melioidosis and blood polymerase-chain reaction for leptospirosis, which occurred among rescuers involved in a search and rescue operation for a young man who was suspected to have drowned in Lubuk Yu, a recreational forest in Pahang, Malaysia. Despite treatment, three of the patients died from the co-infection.     

Salmonella Paratyphi A liver abscess—Secondary infection of an amoebic liver abscess?

Liver abscess is a rare complication of both enteric fever and non-enteric salmonella infection. We present an unusual case of Salmonella Paratyphi A liver abscess, where secondary bacterial infection of an amoebic liver abscess was suspected.     

Tuberculous peritonitis: a Third World's disease?

Tuberculous peritonitis has a high morbidity and mortality. The clinical outcome of tuberculous peritonitis depends on an early diagnosis and treatment. We review five cases of tuberculous peritonitis diagnosed in a short stay medical unit over a one-year period. All patients were successfully treated with antituberculous drugs. The clinical management of this disease is described and current views regarding the value of computed tomography and other diagnostic techniques are discussed.