A systematic review of gut microbiota composition in observational studies of major depressive disorder, bipolar disorder and schizophrenia

The emerging understanding of gut microbiota as 'metabolic machinery' influencing many aspects of physiology has gained substantial attention in the field of psychiatry. This is largely due to the many overlapping pathophysiological mechanisms associated with both the potential functionality of the gut microbiota and the biological mechanisms thought to be underpinning mental disorders. In this systematic review, we synthesised the current literature investigating differences in gut microbiota composition in people with the major psychiatric disorders, major depressive disorder (MDD), bipolar disorder (BD) and schizophrenia (SZ), compared to 'healthy' controls. We also explored gut microbiota composition across disorders in an attempt to elucidate potential commonalities in the microbial signatures associated with these mental disorders. Following the PRISMA guidelines, databases were searched from inception through to December 2021. We identified 44 studies (including a total of 2510 psychiatric cases and 2407 controls) that met inclusion criteria, of which 24 investigated gut microbiota composition in MDD, seven investigated gut microbiota composition in BD, and 15 investigated gut microbiota composition in SZ. Our syntheses provide no strong evidence for a difference in the number or distribution (α-diversity) of bacteria in those with a mental disorder compared to controls. However, studies were relatively consistent in reporting differences in overall community composition (β-diversity) in people with and without mental disorders. Our syntheses also identified specific bacterial taxa commonly associated with mental disorders, including lower levels of bacterial genera that produce short-chain fatty acids (e.g. butyrate), higher levels of lactic acid-producing bacteria, and higher levels of bacteria associated with glutamate and GABA metabolism. We also observed substantial heterogeneity across studies with regards to methodologies and reporting. Further prospective and experimental research using new tools and robust guidelines hold promise for improving our understanding of the role of the gut microbiota in mental and brain health and the development of interventions based on modification of gut microbiota.

The limping child: an algorithm to outrule musculoskeletal sepsis

BACKGROUND

The acutely limping child presents a significant diagnostic challenge.

AIM

The purpose of this study was to create a clinically useful algorithm to allow exclusion of 'musculoskeletal sepsis' as a differential diagnosis in the child presenting with limp.

METHODS

Data were collected on all 286 limping children admitted to our centre over a 3-year-period. Using logistic regression analysis, the predictive model was constructed, to exclude infection.

RESULTS

Duration of symptoms, constitutional symptoms, temperature, white cell count and ESR were significantly different in children with musculoskeletal infection (P < 0.05). Multivariate analysis demonstrated that when all three variables of duration of symptoms >1, <5 days; temperature >37.0 degrees C; and ESR >35 mm/h were present, the predicted probability of infection was 0.66, falling to 0.01 when none were present.

CONCLUSION

This multivariate model enables us to rule out musculoskeletal infection with 99% certainty in limping children with none of these three presenting variables.

A systemic provascular response in bone marrow to musculoskeletal trauma in mice

Post-natal vasculogenesis, the process by which vascular committed bone marrow stem cells or endothelial precursor cells migrate, differentiate and incorporate into the nacent endothelium and thereby contribute to physiological and pathological neurovascularisation, has stimulated much interest. Its contribution to neovascularisation of tumours, wound healing and revascularisation associated with ischaemia of skeletal and cardiac muscles is well established. We evaluated the responses of endothelial precursor cells in bone marrow to musculoskeletal trauma in mice.

Bone marrow from six C57 Black 6 mice subjected to a standardised, closed fracture of the femur, was analysed for the combined expression of cell-surface markers stem cell antigen 1 (sca-1+) and stem cell factor receptor, CD117 (c-kit+) in order to identify the endothelial precursor cell population. Immunomagnetically-enriched sca-1+ mononuclear cell (MNCsca-1+) populations were then cultured and examined for functional vascular endothelial differentiation. Bone marrow MNCsca-1+,c-kit+ counts increased almost twofold within 48 hours of the event, compared with baseline levels, before decreasing by 72 hours.

Sca-1+ mononuclear cell populations in culture from samples of bone marrow at 48 hours bound together Ulex Europus-1, and incorporated fluorescent 1,1′-dioctadecyl- 3,3,3,’3′-tetramethylindocarbocyanine perchlorate-labelled acetylated low-density lipoprotein intracellularily, both characteristics of mature endothelium.

Our findings suggest that a systemic provascular response of bone marrow is initiated by musculoskeletal trauma. Its therapeutic manipulation may have implications for the potential enhancement of neovascularisation and the healing of fractures.

Mobilization of endothelial precursor cells: systemic vascular response to musculoskeletal trauma

Postnatal vasculogenesis, the process by which vascular committed bone marrow stem cells or endothelial precursor cells (EPC) migrate, differentiate, and incorporate into the nacent endothelium contributing to physiological and pathological neovascularization, has stimulated much interest. Its contribution to tumor nonvascularization, wound healing, and revascularization associated with skeletal and cardiac muscles ischaemia is established. We evaluated the mobilization of EPCs in response to musculoskeletal trauma. Blood from patients (n = 15) following AO type 42a1 closed diaphyseal tibial fractures was analyzed for CD34 and AC133 cell surface marker expression. Immunomagnetically enriched CD34+ mononuclear cell (MNC(CD34+)) populations were cultured and examined for phenotypic and functional vascular endothelial differentiation. Circulating MNC(CD34+) levels increased sevenfold by day 3 postinjury. Circulating MNC(AC133+) increased 2.5-fold. Enriched MNC(CD34+) populations from day 3 samples in culture exhibited cell cluster formation with sprouting spindles. These cells bound UEA-1 and incorporated fluorescent DiI-Ac-LDL intracellularily. Our findings suggest a systemic provascular response is initiated in response to musculoskeletal trauma. Its therapeutic manipulation may have implications for the potential enhancement of fracture healing.

An outcomes assessment of intra-articular calcaneal fractures, using patient and physician's assessment profiles

Thirty-six patients with intra-articular displaced calcaneal fractures were examined to determine both physician- and patient-based outcomes. Three groups were selected. Group A was treated with open reduction and internal fixation, group B was treated with open reduction internal fixation and supplemental bone graft augmentation and the patients in group C were treated with plaster cast immobilisation and no formal operative treatment. All cohorts were well matched for age, sex and severity of injury. Patients were evaluated using both the American Foot and Ankle Society Scoring System (AFASS) and the short form 36 (SF-36). Minimum time to follow up was 4 years. No significant difference was observed between the three groups with regards to pain and functional outcomes using the AFASS score (P>0.05). No difference was observed between the three groups using the SF-36 score (P>0.1). A statistically significant difference was observed, using radiological criteria, between both groups A and B when compared to the non-operative group C. The rate of wound infection in groups A and B was 31.5%. No correlation was found between the SF-36 score and the AFASS score. No correlation was found between the radiological score and either the SF-36 or the AFASS score. This study has found that the conservative treatment of calcaneal fractures can produce satisfactory outcomes with lower morbidity than surgically treated fractures.

Early experience with titanium elastic nails in a trauma unit

The Titanium Elastic Nail (TEN) offers a number of potential advantages over traditional ways of treating long bone fractures particularly in the paediatric population. These advantages include earlier mobilisation and shorter hospital stay and less risk of loss of fracture position. These advantages are most apparent and significant when treating femoral fractures in children where the length of hospital stay is reduced from several weeks to a typical period of 5 to 8 days. We have reviewed our early experience of using these implants over the past 2 years. Patients were assessed clinically and radiologically. 13 patients were treated using the TEN during this period. There were 2 femoral fractures, 4 humeral fractures, 1 tibial and 6 forearm fractures treated using the Titanium Elastic Nail. All fractures united during the study period. However 1 humeral fracture required a secondary bone grafting and plating for delayed union and 1 fracture lost position during follow-up. Insertion point pain was a problem in 4 patients but this resolved after nail removal in all. There was 1 superficial wound infection which resolved with antibiotics and 1 superficial wound infection of an open fracture wound which resolved following nail removal and antibiotics. There were no cases of deep infection. There were no limb length discrepancy or rotational or angular malalignment problems. Biomechanical principles and technical aspects of this type of fixation are discussed.

Lisfranc injuries: patient- and physician-based functional outcomes

The purpose of this study was to assess functional outcome of patients with a Lisfranc fracture dislocation of the foot by applying validated patient- and physician-based scoring systems and to compare these outcome tools. Of 25 injuries sustained by 24 patients treated in our institution between January 1995 and June 2001, 16 were available for review with a mean follow-up period of 36 (10-74) months. Injuries were classified according to Myerson. Outcome instruments used were: (a) Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), (b) Baltimore Painful Foot score (PFS) and (c) American Orthopedic Foot and Ankle Society (AOFAS) mid-foot scoring scale. Four patients had an excellent outcome on the PFS scale, seven were classified as good, three fair and two poor. There was a statistically significant correlation between the PFS and Role Physical (RP) element of the SF-36.

Late presentation of developmental dysplasia of the hip

BACKGROUND

A neonatal screening programme for developmental dysplasia of the hip (DDH) is ongoing in Cork. Despite early screening, infants continue to present at later ages with DDH. The impact of late diagnosis is significant. Established DDH causes significant morbidity and may have major medicolegal implications.

AIM

To identify the reasons for the late presentation of DDH in the presence of a screening programme.

METHODS

In a retrospective study all cases of late DDH presenting from 1988 to 2000 were identified using inpatient database.

RESULTS

Forty-nine cases of DDH were diagnosed. The mean age of diagnosis was 14.8 months (range 6-47). Multiple risk factors were identified in four patients only. More than one risk factor was identified in 10 patients.

CONCLUSION

Despite screening, children continue to present with late DDH. In this study, only 14 patients had multiple risk factors and only four patients had more than two risk factors, highlighting the low incidence of suspicion in this patient group.

Compartment syndrome without pain!

We report the case of a young male patient who underwent intra-medullary nailing for a closed, displaced mid-shaft fracture of tibia and fibula. He was commenced on patient controlled analgesia post-operatively. A diagnosis of compartment syndrome in the patient's leg was delayed because he did not exhibit a pain response. This ultimately resulted in a below-knee amputation of the patient's leg. We caution against the use of patient controlled analgesia in any traumatised limb distal to the hip or the shoulder.

A simple method of plate fixation of fractures of the frontal bone

We present a simple method to reduce and align depressed fractures of the frontal sinus or cranial vault before rigid fixation using microplates.

Intraneural ganglion of the peroneal nerve: a case report

Intraneural ganglion is a rare condition. We present a case of peroneal nerve palsy due to an intraneural ganglion of the peroneal nerve. Full recovery followed surgical decompression. Apparent idiopathic foot drop is an indication for exploration of the common peroneal nerve.

Percutaneous screw fixation of tibial plateau fractures

A series of 13 patients with displaced fractures of the tibial plateau treated by closed reduction and percutaneous pinning have been reviewed 17 months after surgery. All the operations were performed using image intensification to aid reduction of the fracture by ligamentotaxis and to guide screw placement. In two cases, arthroscopy was used in addition to facilitate elevation of the articular surface using a probe inserted through a cortical window in the proximal tibial metaphysis. The postoperative rehabilitation programme consisted of early mobilization and non-weight bearing for at least 2 months. Of the patients, 11 had a satisfactory result, one patient had a fair result with persistent pain and the other had a poor result when the fixation failed in a comminuted bicondylar fracture in porotic bone. This technique is minimally invasive and avoids many of the complications of both conservative and operative treatment and will have an expanding role to play in the management of these fractures.