Wiskott-Aldrich syndrome protein-deficient mice reveal a role for WASP in T but not B cell activation

The Wiskott-Aldrich syndrome (WAS) is a human X-linked immunodeficiency resulting from mutations in a gene (WASP) encoding a cytoplasmic protein implicated in regulating the actin cytoskeleton. To elucidate WASP function, we disrupted the WASP gene in mice by gene-targeted mutation. WASP-deficient mice showed apparently normal lymphocyte development, normal serum immunoglobulin levels, and the capacity to respond to both T-dependent and T-independent type II antigens. However, these mice did have decreased peripheral blood lymphocyte and platelet numbers and developed chronic colitis. Moreover, purified WASP-deficient T cells showed markedly impaired proliferation and antigen receptor cap formation in response to anti-CD3epsilon stimulation. Yet, purified WASP-deficient B cells showed normal responses to anti-Ig stimulation. We discuss the implications of our findings regarding WASP function in receptor signaling and cytoskeletal reorganization in T and B cells and compare the effects of WASP deficiency in mice and humans.

An overview of the management of flexor tendon injuries

Flexor tendon injuries still remain a challenging condition to manage to ensure optimal outcome for the patient. Since the first flexor tendon repair was described by Kirchmayr in 1917, several approaches to flexor tendon injury have enabled successful repairs rates of 70-90%. Primary surgical repair results in better functional outcome compared to secondary repair or tendon graft surgery. Flexor tendon injury repair has been extensively researched and the literature demonstrates successful repair requires minimal gapping at the repair site or interference with tendon vascularity, secure suture knots, smooth junction of tendon end and having sufficient strength for healing. However, the exact surgical approach to achieve success being currently used among surgeons is still controversial. Therefore, this review aims to discuss the results of studies demonstrating the current knowledge regarding the optimal approach for flexor tendon repair. Post-operative rehabilitation for flexor tendon surgery is another area, which has caused extensive debate in hand surgery. The trend to more active mobilisation protocols seems to be favoured but further study in this area is needed to find the protocol, which achieves function and gliding but avoids rupture of the tendons. Lastly despite success following surgery complications commonly still occur post surgery, including adhesion formation, tendon rupture and stiffness of the joints. Therefore, this review aims to discuss the appropriate management of these difficulties post surgery. New techniques in management of flexor tendon will also be discussed including external laser devices, addition of growth factors and cytokines.

ROS-mediated apoptotic cell death in prostate cancer LNCaP cells induced by biosurfactant stabilized CdS quantum dots

Cadmium sulfide (CdS) quantum dots (QDs) have raised great attention because of their superior optical properties and wide utilization in biological and biomedical studies. However, little is known about the cell death mechanisms of CdS QDs in human cancer cells. This study was designed to investigate the possible mechanisms of apoptosis induced by biosurfactant stabilized CdS QDs (denoted as "bsCdS QDs") in human prostate cancer LNCaP cells. It was also noteworthy that apoptosis correlated with reactive oxygen species (ROS) production, mitochondrial damage, oxidative stress and chromatin condensation in a dose- and time-dependent manner. Results also showed involvement of caspases, Bcl-2 family proteins, heat shock protein 70, and a cell-cycle checkpoint protein p53 in apoptosis induction by bsCdS QDs in LNCaP cells. Moreover, pro-apoptotic protein Bax was upregulated and the anti-apoptotic proteins, survivin and NF-κB were downregulated in bsCdS QDs exposed cells. Protection of N-acetyl cysteine (NAC) against ROS clearly suggested the implication of ROS in hyper-activation of apoptosis and cell death. It is encouraging to conclude that biologically stabilized CdS QDs bear the potential of its applications in biomedicine, such as tumor therapy specifically by inducing caspase-dependent apoptotic cell death of human prostate cancer LNCaP cells.

Bisphosphonates and their influence on fracture healing: a systematic review

Bisphosphonates are commonly used in osteoporosis, but concerns have been raised about possible negative effects on fracture healing. We systematically reviewed the literature and found that bisphosphonates significantly prolong union times of distal radius fractures but not femoral fractures. The timing of bisphosphonate introduction does not affect fracture union time.

INTRODUCTION

Bisphosphonates are the most commonly prescribed drugs in patients suffering from and at higher risk of developing osteoporosis. However, concerns have been raised as to whether these drugs have a negative effect on fracture healing. The aim of this systematic review is to explore further these concerns.

METHODS

A literature review was performed in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All relevant articles found via MEDLINE, Cochrane, CINAHL, EMBASE and Google Scholar were screened. Studies with information on bisphosphonates' effect on fracture healing in humans were included and systematically reviewed.

RESULTS

Patients with distal radius fractures on bisphosphonates had a significantly longer union time compared with controls, but not patients with femoral fractures. No correlation between timing of bisphosphonate introduction and union time for fractures was found. Although one study reported a higher humeral non-union associated with bisphosphonate introduction following the fracture, there was no evidence that bisphosphonate introduction, timing or dose resulted in a significant delay in union following other fractures.

CONCLUSIONS

This systematic review has shown that bisphosphonates significantly prolong union times of distal radius fractures. Some clinical findings are in contrast with preclinical studies highlighting the need to develop better animal models to study osteoporosis, treatment and fracture healing. There is also a need for more well-constructed studies looking at the clinical effect of bisphosphonate on fracture healing in a large number of patients. These robust studies need to look at union time and non-union rates as a function of duration and dose of different bisphosphonates in different upper and lower limb fractures.

Clindamycin in the treatment of osteomyelitis in children: a report of 29 cases

Clindamycin phosphate was used in the treatment of 29 children with osteomyelitis of whom 25 had an acute and four a chronic type of infection. The usual dose was 50 mg/kg/day intravenously for approximately three weeks followed by oral clindamycin palmitate at home in a dose of 30 mg/kg/day for an additional six weeks. Staphylococcus aureus was isolated in 22 of 29 cases: 96% of strains were penicillin resistant. The clinical and bacteriologic results in the present series were good to excellent. There was prompt clinical and bacteriologic response shortly after initiation of clindamycin therapy. Good bone penetration of the drug was observed. Long-term evaluation revealed satisfactory clinical and roentgenographic progress in all patients. No diarrhea or manifestations of enterocolitis appeared in any patient in spite of high doses of the drug for intervals up to nine weeks.

Cerebrospinal fluid lactic acid levels in meningitis

Measurement of cerebrospinal fluid lactic acid by gas liquid chromatography and by an enzymatic Monotest lactate test was evaluated for the early detection of bacterial meningitis in 396 patients. Spinal fluid specimens from 62/62 patients with a bacterial or mycoplasma etiology yielded lactate levels greater than the upper limits of normal, whereas specimens from 334 patients with no bacterial involvement gave values within the normal range. The duration of elevated CSF lactate values coincided with the clinical response to therapy. When considered along with the history and physical examination of the patient, determination of lactic acid proved to be a rapid and reliable diagnostic test for the early detection of untreated as well as partially treated pyogenic meningitis.

Stem cell therapy for human cartilage defects: a systematic review

OBJECTIVES

The use of stem cell therapy for the repair of cartilage defects has shown promising results in in vitro and animal studies. However, only a small number of studies have been performed to evaluate the benefits in human subjects. The aim of this study is to systematically review studies that focus on the clinical application of stem cell therapy to treat cartilage defects in human subjects.

DESIGN

A literature search was performed, adhering to the PRISMA guidelines, to review any studies using such techniques in humans. Our initial search retrieved 105 articles listed on MEDLINE, EMBASE, Google Scholar, CINHal and SPortDiscus. From these studies, 11 studies meeting the eligibility criteria were selected and formed the basis of our systematic review.

RESULTS

There is limited evidence showing the benefit in humans. The study designs, follow-up methods and criteria reporting and evaluation vary greatly between the studies and are outlined in our systematic review.

CONCLUSION

With an increasing body of evidence in non-human and in vitro studies, more human trials are required. More high level studies with extensive and robust validated reporting methods should be conducted to evaluate the true effect of such techniques in human cartilage defect repairs.

Repair of distal biceps tendon rupture with the Biotenodesis screw

BACKGROUND

Distal biceps tendon ruptures are uncommon injuries with only around 300 cases reported in the literature. Current management tends to favour anatomical reinsertion of the tendon into the radial tuberosity, especially in young and active individuals. These injuries are commonly repaired using either a single anterior incision with suture anchors or the Boyd-Anderson dual incision technique.

CASE REPORT

We report the use of a bioabsorbable interference screw for the repair of distal biceps tendon rupture using a minimal incision technique. In this technique the avulsed tendon and a bioabsorbable screw are secured in a drill hole on the radial tuberosity using whip stitch and fibre wire sutures according to Biotenodesis system guidelines.

CONCLUSION

The technique described requires minimal volar dissection that is associated with a reduced number of synostosis and posterior interosseous nerve injuries. The bioabsorbable interference screw has all the advantages of being biodegradable and has been shown to have greater pullout strength than suture anchors. It is also a reasonable alternative to titanium screws in terms of primary fixation strength. The strong fixation provided allows early active motion and return to previous activities as seen in our case.

Stress fractures of the foot and ankle

Stress fractures occur as a result of microscopic injuries sustained when bone is subjected to repeated submaximal stresses. Overtime, with repeated cycles of loading, accumulation of such injuries can lead to macro-structural failure and frank fracture. There are numerous stress fractures about the foot and ankle of which a trauma and orthopaedic surgeon should be aware. These include: metatarsal, tibia, calcaneus, navicular, fibula, talus, medial malleolus, sesamoid, cuneiform and cuboid. Awareness of these fractures is important as the diagnosis is frequently missed and appropriate treatment delayed. Late identification can be associated with protracted pain and disability, and may predispose to non-union and therefore necessitate operative intervention. This article outlines the epidemiology and risk factors, aetiology, presentation and management of the range of stress fractures in the foot and ankle.

Principles of hand fracture management

The hand is essential in humans for physical manipulation of their surrounding environment. Allowing the ability to grasp, and differentiated from other animals by an opposing thumb, the main functions include both fine and gross motor skills as well as being a key tool for sensing and understanding the immediate surroundings of their owner. Hand fractures are the most common fractures presenting at both accident and emergency and within orthopaedic clinics. Appropriate evaluation at first presentation, as well as during their management, can significantly prevent both morbidity and disability to a patient. These decisions are dependant on a wide range of factors including age, hand dominance, occupation and co-morbidities.A fracture is best described as a soft tissue injury with an associated bony injury. Despite this being the case, this paper intends to deal mainly with the bone injury and aims to discuss both the timing, as well as the methods available, of hand fracture management.

The epidemiology, genetics and future management of syndactyly

Syndactyly is a condition well documented in current literature due to it being the most common congenital hand defect, with a large aesthetic and functional significance.There are currently nine types of phenotypically diverse non-syndromic syndactyly, an increase since the original classification by Temtamy and McKusick(1978). Non-syndromic syndactyly is inherited as an autosomal dominant trait, although the more severe presenting types and sub types appear to have autosomal recessive and in some cases X-linked hereditary.Gene research has found that these phenotypes appear to not only be one gene specific, although having individual localised loci, but dependant on a wide range of genes and subsequent signalling pathways involved in limb formation. The principal genes so far defined to be involved in congenital syndactyly concern mainly the Zone of Polarizing Activity and Shh pathway.Research into the individual phenotypes appears to complicate classification as new genes are found both linked, and not linked, to each malformation. Consequently anatomical, phenotypical and genotypical classifications can be used, but are variable in significance, depending on the audience.Currently, management is surgical, with a technique unchanged for several decades, although future development will hopefully bring alternatives in both earlier diagnosis and gene manipulation for therapy.

An outbreak of Hemophilus influenzae type b meningitis in an enclosed hospital population

Five cases of HITB maningitis occurred within six months in an enclosed population of 28 to 32 chronically ill children. Studies of nasopharyngeal carriage and serum HITB anticapsular antibodies were started after the third case occurred. Two patients had low (less than 0.04 and 0.05mug/ml) antibodies and were not carriers when studied prior to onset of their disease. The carriage rate was approximately 20% among the children. Carriage was usually prolonged, and acquisition was not prevented by high antibody levels. Attempts to arrest this outbreak with type b polysaccharide immunization and ampicillin therapy are discussed in the context of HITB meningitis as a contagious disease.

Studies on the protective effect of flaxseed oil on cisplatin-induced hepatotoxicity

Cisplatin (CP) is known as one of the most potent chemotherapeutic antitumor drugs. The tissue-specific toxicity of CP in the kidneys is well documented. However, at higher doses less common toxic effects such as hepatotoxicity may arise. Since CP remains one of the most effective antineoplastic drug used in chemotherapy, strategies to protect tissues against CP toxicity are of clinical interest. Recently, ω-3 polyunsaturated fatty acids (PUFAs) from certain plants/seeds notably flaxseed have shown numerous health benefits. In view of this, the present study investigates the protective effect of flaxseed oil (FXO) on CP-induced damage in liver. Rats were pre-fed normal diet and the diet rich in FXO for 10 days and then a single dose of CP (6 mg/kg body weight) was administered intraperitoneally while still on diet. Serum/urine parameters, enzymes of carbohydrate metabolism and oxidative stress were analyzed. CP caused perturbation of the antioxidant defense as reflected by the decrease in the activities of catalase, superoxide dismutase and glutathione peroxidase. Further the activities of various enzymes involved in glycolysis, tricarboxylic acid cycle, gluconeogenesis and hexose monophosphate shunt pathways were determined and were found to be differentially altered by CP treatment. However, these alterations were ameliorated in CP-treated rats fed on FXO. Present results show that dietary supplementation of FXO in CP-treated rats ameliorated CP-induced hepatotoxic and other deleterious effects due to its intrinsic biochemical/antioxidant properties.

Adult native knee extensor mechanism ruptures

Extensor mechanism rupture is a serious event requiring prompt diagnosis and treatment. Patella fractures are reportedly six times more frequent than soft tissue injuries such as quadriceps or patella tendon ruptures. Classically quadriceps and patella tendon ruptures are seen more in males, with those over 40 predominantly suffering from quadriceps tendon ruptures, often associated with an underlying condition, whereas patella tendon ruptures are mostly associated with sport injuries and are commonly seen in the under 40s. Almost all types of extensor mechanism ruptures benefit from early management which typically involves surgery. Diagnosis can be deemed easy to make by demonstrating inability to actively extend the knee, this however can be easily overlooked and missed in a busy emergency department leading to a late diagnosis and necessitating more complex surgery. Earlier surgical intervention and rehabilitation tend to produce improved outcomes.

Association of pulmonary artery catheter use with in-hospital mortality

OBJECTIVE

To determine the association of pulmonary artery catheter (PAC) use with in-hospital mortality.

DESIGN

Prospective, observational study.

SETTING

The medical intensive care units (MICU) of two teaching hospitals.

METHODS

The study included 751 adults who were admitted to the MICU, excluding those who stayed for <24 hrs. Demographics and the worst Acute Physiology and Chronic Health Evaluation (APACHE) II score within the first 24 hrs of MICU admission were obtained. Daily logistic organ dysfunction system (LODS) scores were calculated. The associations of in-hospital mortality with the admission source, admission disease category, APACHE II scores, the worst LODS scores, mechanical ventilation, and PAC use were determined using chi-square, Mann-Whitney U, and multiple logistic regression analysis tests. p Values < 0.05 were considered significant.

RESULTS

Mean patient age was 52.6 +/- 17.1 yrs; 425 (57%) were male; 464 (62%) were African-American, 275 (37%) Caucasian, 6 (1%) Asian, and 6 (1%) Hispanic. PAC was used in 119/751 (16%). The median APACHE II and worst LODS scores were 19 and 4, respectively. The in-hospital mortality rate was 159/751 (21%). The median APACHE II score for survivors was 17.5, compared with 28.0 for nonsurvivors (p <.0001). The worst median LODS score was 4 for survivors, compared with 11 for nonsurvivors (p <.0001). Sixty-four (54%) of the 119 patients with PAC died, compared with 95 (15%) of the 632 without PAC (p <.0001). Multiple logistic regression analysis showed that higher APACHE II-predicted mortality rate (p =.0088) and worst daily LODS score (p <.0001) were associated with increased mortality. The admission source, admission disease category, PAC use, and mechanical ventilation were not associated with in-hospital mortality.

CONCLUSIONS

This study could not detect an association between PAC use and mortality. The APACHE II-predicted mortality rate and the development of multiple organ dysfunction were the main determinants of poor outcome in critically ill patients admitted to MICU.

Use of unconventional methods of therapy by cancer patients in Pakistan

Most of the studies related to the use of unconventional methods of therapy by cancer patients have been carried out in the developed countries. This study was conducted to ascertain the frequency, type, and duration of use of unconventional methods of therapy by cancer patients in Pakistan. We also wanted to identify individuals who are most likely to use these methods and to compare the findings with those reported from the developed countries. Between 1 April and 30 May 1994, all patients with histologically proven cancer who visited the oncology unit were interviewed. A printed questionnaire with questions and options was used as an interview guide. Informed consent was obtained. One hundred and ninety-one patients were interviewed, on average, for 25 minutes each. Use of unconventional methods of therapy by cancer patients was widespread (54.5% of all patients). The majority (83.7%) were influenced by family members to use these methods. Traditional herbal medicines (70.2%) and homeopathy (64.4%) were the most commonly employed methods. Thirty-six percent of the users employed these methods before receiving any conventional therapy. Only 15% used these methods after conventional therapeutic options had been exhausted. Patients generally perceived these methods as useful, non-toxic and inexpensive. Age, marital status, socio-economic background, education level and status of underlying neoplasm did not influence the frequency of use of unconventional methods. The use, however, was influenced by gender, family size, and type of underlying malignancy. Patients aware of their diagnosis were less likely to use these methods. This study suggests that use of unconventional methods by cancer patients in Pakistan is widespread. Unlike western countries, these methods are often employed before receiving any conventional therapy. This probably results in a significant delay which can be expected to adversely influence the subsequent disease management and survival. Public education, reduction of cost and easy availability of conventional therapy may be helpful in reducing the use of methods which otherwise may have no proven value.

Arachidonic and cis-unsaturated fatty acids induce selective platelet substrate phosphorylation through activation of cytosolic protein kinase C

The ability of arachidonic acid and other fatty acids to induce phosphorylation of endogenous substrates and the role of protein kinase C in mediating these effects were examined. In a cell-free cytosolic system derived from human platelets, arachidonic, oleic, and other cis-unsaturated fatty acids induced a dose-dependent phosphorylation of several endogenous substrates. These substrates form a subset of phorbol ester-induced phosphorylations. Multiple lines of evidence suggested the direct involvement of protein kinase C in mediating fatty acid-induced phosphorylations. These observations suggest that arachidonic acid and other unsaturated fatty acids are capable of activating protein kinase C in a physiologic environment resulting in the phosphorylation of multiple endogenous substrates.

Management of extensor tendon injuries

Extensor tendon injuries are very common injuries, which inappropriately treated can cause severe lasting impairment for the patient. Assessment and management of flexor tendon injuries has been widely reviewed, unlike extensor injuries. It is clear from the literature that extensor tendon repair should be undertaken immediately but the exact approach depends on the extensor zone. Zone I injuries otherwise known as mallet injuries are often closed and treated with immobilisaton and conservative management where possible. Zone II injuries are again conservatively managed with splinting. Closed Zone III or ‘boutonniere’ injuries are managed conservatively unless there is evidence of displaced avulsion fractures at the base of the middle phalanx, axial and lateral instability of the PIPJ associated with loss of active or passive extension of the joint or failed non-operative treatment. Open zone III injuries are often treated surgically unless splinting enable the tendons to come together. Zone V injuries, are human bites until proven otherwise requires primary tendon repair after irrigation. Zone VI injuries are close to the thin paratendon and thin subcutaneous tissue which strong core type sutures and then splinting should be placed in extension for 4-6 weeks. Complete lacerations to zone IV and VII involve surgical primary repair followed by 6 weeks of splinting in extension. Zone VIII require multiple figure of eight sutures to repair the muscle bellies and static immobilisation of the wrist in 45 degrees of extension. To date there is little literature documenting the quality of repairing extensor tendon injuries however loss of flexion due to extensor tendon shortening, loss of flexion and extension resulting from adhesions and weakened grip can occur after surgery. This review aims to provide a systematic examination method for assessing extensor injuries, presentation and management of all type of extensor tendon injuries as well as guidance on mobilisation pre and post surgery.

Expression of heat shock protein 27 in developing and adult human kidney

The expression of heat shock protein (hsp) 27 was examined in the developing and adult human kidney. Immunolocalization using a monoclonal antibody against human hsp 27 demonstrated immunoreactivity in both the developing and adult kidney. Low to moderate immunoreactivity for hsp 27 was observed in the fetal and adult proximal tubule, distal tubule, and mesangial cells of the glomeruli. Intense immunoreactivity for hsp 27 was localized to the cortical and medullary collecting ducts in both the adult and fetal kidney, with the most intense staining in the medullary regions. The loop of Henle demonstrated no immunoreactivity for hsp 27. The blastemal element of the developing kidney showed no hsp immunostaining and the ureteric bud demonstrated moderate staining. Western, northern, and reverse transcription-polymerase chain reaction (RT-PCR) analyses disclosed no significant differences in hsp 27 mRNA or protein level as a function of gestational age. An analysis of the phosphorylation state of hsp 27 showed the majority of hsp 27 to be present in the unphosphorylated isoform for both adult and fetal samples. These studies are the first to demonstrate the presence of hsp 27 in the human kidney. It is suggested that this pool of hsp 27 is constitutive as it appears in an inactivated state; localized to the cytoplasm and in an unphosphorylated state.

Posterolateral corner injuries: Epidemiology, anatomy, biomechanics and diagnosis

Increased internal and external rotational laxity of the knee may result from a wide range of pathologies in or around the knee. However, the principal cause of increased external rotational laxity is damage to the posterolateral corner (PLC). The aim of the review is to discuss the epidemiology, anatomy, biomechanics and diagnosis of PLC injuries.