Misunderstanding of leptospirosis

Leptospirosis is an emergent zoonosis implicating major health concern in developing countries, especially in tropical regions with frequent flooding (Watson et al., 2007). Leptospiral infections are rapidly onset and have long incubation periods of up to 28 days. Such long incubation of Leptospires leads to difficulty in identification of the medical condition as an infection-based disease, and was once misidentified as a host self-immune disorder by the clinicians. After decades of incidents, leptospirosis was first reported in 1886 as infectious disease, and Leptospira was identified as the causative bacteria in 1916 (Inada, 1908; Weil, 1886). Much confusion and misunderstanding surround the diagnosis and prevention of leptospirosis have contributed to the delayed treatment and poor prognosis

Recent updates on phthalate exposure and human health: a special focus on liver toxicity and stem cell regeneration

Phthalates have been blended in various compositions as plasticizers worldwide for a variety of purposes. Consequently, humans are exposed to a wide spectrum of phthalates that needs to be researched and understood correctly. The goal of this review is to focus on phthalate's internal exposure pathways and possible role of human digestion on liver toxicity. In addition, special focus was made on stem cell therapy in reverting liver toxicity. The known entry of higher molecular weight phthalates is through ingestion while inhalation and dermal pathways are for lower molecular weight phthalates. In human body, certain phthalates are digested through phase 1 (hydrolysis, oxidation) and phase 2 (conjugation) metabolic processes. The phthalates that are made bioavailable through digestion enter the blood stream and reach the liver for further detoxification, and these are excreted via urine and/or feces. Bis(2-ethylhexyl) phthalate (DEHP) is a compound well studied involving human metabolism. Liver plays a pivotal role in humans for detoxification of pollutants. Thus, continuous exposure to phthalates in humans may lead to inhibition of liver detoxifying enzymes and may result in liver dysfunction. The potential of stem cell therapy addressed herewith will revert liver dysfunction and lead to restoration of liver function properly

Distribution and prevalence of microorganisms causing diabetic foot infection in Hospital Serdang and Hospital Ampang for the year 2010 to 2014

Background: In developing countries like Malaysia, the prevalence of diabetes mellitus is increasing at an alarming rate. Various complications develop in patients diagnosed with diabetes. Diabetic foot is one such complication that is a threat to morbidity and mortality rate owing to its risk of amputation. Understanding the microbiology of diabetic foot infection becomes an essential part of management as it can help to channel the exact treatment rather than empirical treatment. Aim: To determine the distribution and prevalence of microorganism causing diabetic foot infection in Hospital Serdang and Hospital Ampang for the year 2010 till 2014. Methodology: This was a cross-sectional study using retrospective data from January 2010 to December 2014 of 885 patients with diabetic foot infection in Hospital Serdang and Hospital Ampang, tertiary hospitals in Klang Valley. Data were analyzed using IBM SPSS Statistics version 22.0 for Windows. Results: A total of 1356 pathogens were isolated from 885 patients, with a rate of 1.53 isolates per culture (IPC). The prevalence of gram-negative bacteria was predominant in DFI accounting for 71.27% whereas gram-positive was only 28.73%. Among the gram-negative isolates, the most common pathogen was Pseudomonas aeroginosa accounting for 24.49% followed by Proteus mirabilis (14.34%) and Klebsiella spp. (11.12%). Gram-positive isolates consist of Staphylococcus aureus with a percentage of 66.77% and Streptococcus spp. 33.23%. The Methicillin-Resistant Staphylococcus aureus (MRSA) accounts for 26.24% of the isolates. There were more monomicrobial cultures than polymicrobial culture (465 vs. 420). The most common antibiotic prescribed is ampicillin/sulbactam (55.57%) followed by cloxacillin (13.29%) and penicillin (10.77%). Conclusion: The prevalence of gram-negative bacteria in DFI is higher than gram-positive bacteria. The most common gram-negative bacteria is Pseudomonas aeroginosa followed by Proteus mirabilis and Klebsiella spp. whereas the most common gram-positive bacteria is Staphylococcus aureus. The rate of monomicrobial infection is slightly higher than polymicrobial infection. Ampicillin/sulbactam is the most commonly prescribed antibiotic for a patient with DFI

Mechanisms of oral bacterial virulence factors in pancreatic cancer

Pancreatic cancer is a highly lethal disease, and most patients remain asymptomatic until the disease enters advanced stages. There is lack of knowledge in the pathogenesis, effective prevention and early diagnosis of pancreatic cancer. Recently, bacteria were found in pancreatic tissue that has been considered sterile before. The distribution of flora in pancreatic cancer tissue was reported to be different from normal pancreatic tissue. These abnormally distributed bacteria may be the risk factors for inducing pancreatic cancer. Therefore, studies on combined effect of multi-bacterial and multi-virulence factors may add to the knowledge of pancreatic cancer pathogenesis and aid in designing new preventive and therapeutic strategies. In this review, we outlined three oral bacteria associated with pancreatic cancer and their virulence factors linked with cancer

Colonization of Methicillin-Resistant Staphylococcus aureus (MRSA) among medical students in tertiary institution in Central Malaysia

Methicillin-resistant Staphylococcus aureus or MRSA infection is virulent and presents with a broad spectrum of severity. Limited regional reports that specifically outlined the potential risk of medical students being part of the dissemination of MRSA in healthcare settings were noted. This study aims to assess the prevalence and contributory factors of colonization of MRSA on neckties, headscarves, and ID badges among medical students in a local medical university in Malaysia. A cross-sectional study was conducted involving 256 medical students. A validated questionnaire was used to collect the data, and sample swabs were collected between July and August 2013 by swabbing neckties, headscarves, or identification badges. The swabs were then streaked onto mannitol salt agar (MSA) and incubated at 37 °C overnight. Out of 433 samples taken, 40 swabs (9.24%) were positive for Staphylococcus aureus. Out of the 40 swabs, five (12.5%) isolates were MRSA (one culture was isolated from the headscarf of a preclinical student, one culture was isolated from the necktie of clinical students, while the remaining three were isolated from identification badges of clinical students. There was no significant association between age, gender, ethnicity, and phase of medical students with the colonization of MRSA (p > 0.05). There was a significant association between knowledge score on hand hygiene practice and phase of medical students. MRSA colonies were present on neckties, headscarves, and identification badges of medical students of all phases. The findings from this study suggest the need for improvement of hand hygiene knowledge and discontinuity of mandatory use of physical ID badges and neckties among medical students

Modulatory and regenerative potential of transplanted bone marrow derived mesenchymal stem cells on rifampicin-induced kidney toxicity

Anti-tuberculosis agent rifampicin is extensively used for its effectiveness. Possible complications of tuberculosis and prolonged rifampicin treatment include kidney damage; these conditions can lead to reduced efficiency of the affected kidney and consequently to other diseases. Bone marrow-derived mesenchymal stem cells (BMMSCs) can be used in conjunction with rifampicin to avert kidney damage; because of its regenerative and differentiating potentials into kidney cells. This research was designed to assess the modulatory and regenerative potentials of MSCs in averting kidney damage due to rifampicin-induced kidney toxicity in Wistar rats and their progenies. BMMSCs used in this research were characterized according to the guidelines of International Society for Cellular Therapy

Hypoxia in bone and oxygen releasing biomaterials in fracture treatments using mesenchymal stem cell therapy: a review

Bone fractures have a high degree of severity. This is usually a result of the physical trauma of diseases that affect bone tissues, such as osteoporosis. Due to its highly vascular nature, the bone is in a constant state of remodeling. Although those of younger ages possess bones with high regenerative potential, the impact of a disrupted vasculature can severely affect the recovery process and cause osteonecrosis. This is commonly seen in the neck of femur, scaphoid, and talus bone. In recent years, mesenchymal stem cell (MSC) therapy has been used to aid in the regeneration of afflicted bone. However, the cut-off in blood supply due to bone fractures can lead to hypoxia-induced changes in engrafted MSCs. Researchers have designed several oxygen-generating biomaterials and yielded varying degrees of success in enhancing tissue salvage and preserving cellular metabolism under ischemia. These can be utilized to further improve stem cell therapy for bone repair. In this review, we touch on the pathophysiology of these bone fractures and review the application of oxygen-generating biomaterials to further enhance MSC-mediated repair of fractures in the three aforementioned parts of the bone

Hypoxic-mediated oxidative stress condition and hydroxyapatite-inducing osteogenic differentiation of human mesenchymal stem cells: a mathematical modelling study

Avascular necrosis (AVN) of the bones remains a major clinical challenge. Fractures in the talus, the scaphoid, and the neck of the femur are especially challenging to heal due to the low blood vessel network and the lack of collateral blood supply. These fractures are associated with high rates of nonunion and increased infections that require repeated operations. Conventional treatments by autografting or allografting bone replacement and synthetic bone implants have limitations, including the invasiveness of operative procedures, tissue supply insufficiency, and the risk of host rejection. The advancement in tissue engineering has revealed the potential of stem cells as restorative agents for bone injuries. The administration of mesenchymal stem cells (MSCs) into the talus, the scaphoid, and the neck of the femur could produce enhanced osteogenesis via the manipulation of MSC culture conditions. In this study, we used hydroxyapatite as the nanomaterial, and hypoxic milieu to enhance MSC differentiation capacity into the osteogenic lineage, allowing for more rapid and efficient bone cell replacement treatment. Our results demonstrate 1% oxygen and 12.5 μg/mL of hydroxyapatite (HAP) as the optimal conditions to incorporate the osteogenic medium for the osteogenic induction of MSCs. We also established a proof of concept that the addition of HAP and hypoxic conditions could augment the osteoinductive capacity of MSCs. We also developed an accurate mathematical model to support future bone cell replacement therapy

Dental pulp stem cells therapy overcome photoreceptor cell death and protects the retina in a rat model of sodium iodate-induced retinal degeneration

Blindness and vision loss contribute to irreversible retinal degeneration, and cellular therapy for retinal cell replacement has the potential to treat individuals who have lost light sensitive photoreceptors in the retina. Retinal cells are well characterized in function, and are a subject of interest in cellular replacement therapy of photoreceptors and the retinal pigment epithelium. However, retinal cell transplantation is limited by various factors, including the choice of potential stem cell source that can show variability in plasticity as well as host tissue integration. Dental pulp is one such source that contains an abundance of stem cells. In this study we used dental pulp-derived mesenchymal stem cells (DPSCs) to mitigate sodium iodate (NaIO3) insult in a rat model of retinal degeneration. Sprague-Dawley rats were first given an intravitreal injection of 3 × 105 DPSCs as well as a single systemic administration of NaIO3 (40 mg/kg). Electroretinography (ERG) was performed for the next two months and was followed-up by histological analysis. The ERG recordings showed protection of DPSC-treated retinas within 4 weeks, which was statistically significant (* P ≤ .05) compared to the control. Retinal thickness of the control was also found to be thinner (*** P ≤ .001). The DPSCs were found integrated in the photoreceptor layer through immunohistochemical staining. Our findings showed that DPSCs have the potential to moderate retinal degeneration. In conclusion, DPSCs are a potential source of stem cells in the field of eye stem cell therapy due to its protective effects against retinal degeneration

Natural Products for the Treatment of Chlamydiaceae Infections

Due to the global prevalence of Chlamydiae, exploring studies of diverse antichlamydial compounds is important in the development of effective treatment strategies and global infectious disease management. Chlamydiaceae is the most widely known bacterial family of the Chlamydiae order. Among the species in the family Chlamydiaceae, Chlamydia trachomatis and Chlamydia pneumoniae cause common human diseases, while Chlamydia abortus, Chlamydia psittaci, and Chlamydia suis represent zoonotic threats or are endemic in human food sources. Although chlamydial infections are currently manageable in human populations, chlamydial infections in livestock are endemic and there is significant difficulty achieving effective treatment. To combat the spread of Chlamydiaceae in humans and other hosts, improved methods for treatment and prevention of infection are needed. There exist various studies exploring the potential of natural products for developing new antichlamydial treatment modalities. Polyphenolic compounds can inhibit chlamydial growth by membrane disruption, reestablishment of host cell apoptosis, or improving host immune system detection. Fatty acids, monoglycerides, and lipids can disrupt the cell membranes of infective chlamydial elementary bodies (EBs). Peptides can disrupt the cell membranes of chlamydial EBs, and transferrins can inhibit chlamydial EBs from attachment to and permeation through the membranes of host cells. Cellular metabolites and probiotic bacteria can inhibit chlamydial infection by modulating host immune responses and directly inhibiting chlamydial growth. Finally, early stage clinical trials indicate that polyherbal formulations can be effective in treating chlamydial infections. Herein, we review an important body of literature in the field of antichlamydial research