Air dispersal of multidrug-resistant Acinetobacter baumannii: implications for nosocomial transmission during the COVID-19 pandemic.

AIM: To describe the nosocomial transmission of Air, multidrug-resistant, Acinetobacter baumannii, nosocomial, COVID-19 Acinetobacter baumannii (MRAB) in an open-cubicle neurology ward with low ceiling height, where MRAB isolates collected from air, commonly shared items, non-reachable high-level surfaces and patients were analysed epidemiologically and genetically by whole-genome sequencing. This is the first study to understand the genetic relatedness of air, environmental and clinical isolates of MRAB in the outbreak setting. FINDINGS: Of 11 highly care-dependent patients with 363 MRAB colonization days during COVID-19 pandemic, 10 (90.9%) and nine (81.8%) had cutaneous and gastrointestinal colonization, respectively. Of 160 environmental and air samples, 31 (19.4%) were MRAB-positive. The proportion of MRAB-contaminated commonly shared items was significantly lower in cohort than in non-cohort patient care (0/10, 0% vs 12/18, 66.7%; P<0.001). Air dispersal of MRAB was consistently detected during but not before diaper change in the cohort cubicle by 25-min air sampling (4/4,100% vs 0/4, 0%; P=0.029). The settle plate method revealed MRAB in two samples during diaper change. The proportion of MRAB-contaminated exhaust air grills was significantly higher when the cohort cubicle was occupied by six MRAB patients than when fewer than six patients were cared for in the cubicle (5/9, 55.6% vs 0/18, 0%; P=0.002). The proportion of MRAB-contaminated non-reachable high-level surfaces was also significantly higher when there were three or more MRAB patients in the cohort cubicle (8/31, 25.8% vs 0/24, 0%; P=0.016). Whole-genome sequencing revealed clonality of air, environment, and patients' isolates, suggestive of air dispersal of MRAB. CONCLUSIONS: Our findings support the view that patient cohorting in enclosed cubicles with partitions and a closed door is preferred if single rooms are not available.

Trigger thumbs in children: results of surgical release.

OBJECTIVE. To evaluate results from surgical release of trigger thumbs in children in a regional hospital cluster in Hong Kong. DESIGN. Descriptive case series. SETTING. A regional hospital cluster, Hong Kong. PATIENTS. Data from 1993 to 2009 on 180 children with 209 trigger thumbs were collected. Analyses into gender, predominance of thumb, age of onset, associated abnormalities and family history, symptoms and signs, surgical outcomes, and postoperative complications were carried out retrospectively. RESULTS. There were 92 girls and 88 boys having trigger thumbs (1.05:1). In all, 29 (16%) of the children presented with bilateral trigger thumbs, while the right thumb was singly involved in 81 (45%) and the left thumb in 70 (39%) of the children. The mean age of onset was 19 months; only 20% were diagnosed before the age of 1 year. Only nine (5%) of the children were associated with congenital diseases and none had a positive family history of trigger thumb. Flexion deformity was the major presenting feature, other than triggering or pain. A nodule and flexion deformity were very commonly observed during physical examination. More than 95% of the operated thumbs with transverse incision acquired a good range of movement with a scarcely apparent scar. A residual flexion deformity was evident in only 4%, mostly in children who underwent surgical release under the age of 1 year. CONCLUSION. Surgical release is recommended for children with trigger thumbs aged more than 1 year, which attains satisfactory results with minimal complications.

Palmar fixation of dorsally displaced distal radius fractures using locking plates with Smartlock locking screws.

We performed a prospective cohort study on a consecutive series of 35 unstable, dorsally displaced distal radius fractures, which were treated with palmar locking plates and SmartLock locking screws. There were 17 men and 18 women with a mean age of 44 years who were reviewed at a mean follow-up of 10 months. All the fractures healed at a mean time of 7 weeks. Radiographs did not show any change in alignment from the initial postoperative period until fracture union. The average Mayo wrist score was 90 after fracture union. One patient had an early loss of fracture reduction and one patient developed complex regional pain syndrome. There was no difference in the quality of life before and after surgery. Palmar plate fixation using SmartLock locking screws is effective and safe in stabilising unstable dorsally displaced distal radius fracture and produces good radiological and functional outcomes.

The effectiveness of capsular decompression for internal fixation of intracapsular hip fractures.

PURPOSE: To compare the results of screw fixation plus capsular decompression versus screw fixation alone for managing intracapsular hip fractures. METHODS: Of 201 patients with intracapsular hip fractures, 99 underwent screw fixation with capsular decompression (capsular decompression group) and 102 underwent screw fixation alone (control group). The incidence and time to development of avascular necrosis of the femoral head, union rate, time to union, and other clinical parameters were compared. RESULTS: In patients with displaced fractures, the incidence of avascular necrosis was significantly higher in the control than capsular decompression group, whereas the time to development of this complication was significantly shorter. CONCLUSION: Capsular decompression did not improve the union rate and time to union in undisplaced intracapsular hip fractures, but in displaced fractures it appeared to reduce the incidence and delay the onset of avascular necrosis.

Clinical experience of open carpal tunnel release and Camitz operation in elderly Chinese patients.

OBJECTIVE: To report preliminary experience on the Camitz operation for elderly Chinese patients in a Hong Kong public hospital. DESIGN: Retrospective study. SETTING: Tertiary referral hospital with hand surgery service in Hong Kong. PATIENTS: Between January 2000 and January 2004, patients with carpal tunnel syndrome having the Camitz operation were recruited. They were assessed using the measurements of pinch and grip power, sensation, the Kapandji score, and functional grading as well as complications encountered during the subsequent follow-up. INTERVENTION: The Camitz operation. RESULTS: A total of 21 patients (8 male and 13 female; mean age, 70 years) were recruited. The mean duration of follow-up was 15 months. There was significant improvement in pinch power, grip power, and hand functions, as well as a positive correlation between the functional score and the Kapandji score. No major complication was recorded. One patient with pre-existing osteoarthritis of the ring finger developed contracture of the proximal interphalangeal joint. CONCLUSION: The Camitz operation is a simple, effective, and safe means of improving hand function in elderly Chinese patients with long-standing carpal tunnel syndrome and thenar muscle atrophy. Newly acquired strength in antepulsion of thumb resulted in improved pinch, grip, and hand function in this patient group.

Expression of G protein beta subunits in rat skeletal muscle after nerve injury: Implication in the regulation of neuregulin signaling.

Tight regulation of gene transcription is critical in muscle development as well as during the formation and maintenance of the neuromuscular junction (NMJ). We previously demonstrated that the transcription of G protein beta1 (Gbeta1) is enhanced by treatment of cultured myotubes with neuregulin (NRG), a trophic factor that plays an important role in neural development. In the current study, we report that the transcript levels of Gbeta1 and Gbeta2 subunits in skeletal muscle are up-regulated following sciatic nerve injury or blockade of nerve activity. These observations prompted us to explore the possibility that G protein subunits regulate NRG-mediated signaling and gene transcription. We showed that overexpression of Gbeta1 or Gbeta2 in COS7 cells attenuates NRG-induced extracellular signal-regulated kinase (ERK) 1/2 activation, whereas suppression of Gbeta2 expression in C2C12 myotubes enhances NRG-mediated ERK1/2 activation and c-fos transcription. These results suggest that expression of Gbeta protein negatively regulates NRG-stimulated gene transcription in cultured myotubes. Taken together, our observations provide evidence that specific heterotrimeric G proteins regulate NRG-mediated signaling and gene transcription during rat muscle development.

Comparison between percutaneous transverse fixation and intramedullary K-wires in treating closed fractures of the metacarpal neck of the little finger.

We performed a non-randomized controlled clinical trial of 59 clinical cases to compare percutaneous transverse K-wire fixation and intramedullary K-wires in treating closed fractures of the metacarpal neck of the little finger. Twenty-nine patients were treated by percutaneous transverse K-wire fixation and 30 patients were treated with intramedullary K-wires. They were reviewed at a mean follow-up of 24 months for radiological and functional outcome in terms of union rate, union time, complication rate, pain, movement and grip strength. Radiographs did not show any significant differences in the union rate and union time. There was no statistical difference in complication rate, pain scores, total active motion and grip strength between the two groups. The authors suggest that both methods are comparable, good and safe methods of treating closed, displaced fractures of the metacarpal neck of the little finger, without significant complications.

Comparison of gluteal fasciocutaneous rotational flaps and myocutaneous flaps for the treatment of sacral sores.

To compare the outcomes of gluteal fasciocutaneous rotational flaps and myocutaneous flaps in the treatment of sacral sores, together with a review of surgical complications in two matched cohorts. Thirty-eight patients (18 gluteal fasciocutaneous rotational flaps and 20 myocutaneous flaps) were reviewed retrospectively at a mean follow-up of 58 weeks. The rate of healing of the sore, the sore healing time, and the incidence of surgical complications, together with rate of recurrence, were obtained by chart review. Treatment groups were matched by patient characteristics, operative time and blood loss. The rate of healing of the sore, sore healing time and complication rate were comparable in the two groups but the rate of recurrence was lower to a statistically significant extent in myocutaneous flap patients. The authors suggest that both methods are comparable, good and safe in treating sacral sores; myocutaneous flaps are more durable.

Elderly patients with two episodes of fragility hip fractures form a special subgroup.

PURPOSE: To identify the demographic features of patients aged 65 years or older admitted with 2 episodes of fragility hip fractures. METHODS: From July 2003 to December 2004 inclusive, 50 consecutive elderly patients underwent surgery for a second episode of hip fracture. Patients in a very poor physical condition and therefore unfit for surgery were excluded. Risk factors of fractures in both episodes and whether risk factors were corrected after the first episode were analysed. Detailed radiological assessment and charting of elderly mobility scores and Barthel index were completed and the one-year mortality rate documented. The rehabilitation periods for the 2 episodes of hip fracture were compared. RESULTS: Most patients were female and had trochanteric fractures. In patients aged 65 to 75 years, the incidence of femoral neck fracture occurred as often as trochanteric fracture; while trochanteric fracture was predominant in older patients. Subclinical osteomalacia and undiagnosed hyperthyroidism was found in 3 of the 7 younger patients. Only 30% of them were on treatment for osteoporosis after the first fracture, which underlines the importance of osteoporosis treatment in these patients. CONCLUSION: Elderly patients with 2 episodes of fragility hip fractures form a special subgroup among geriatric hip fracture patients. Fall prevention programmes and treatment for osteoporosis are recommended.

Child behaviour and parenting stress in Hong Kong families.

OBJECTIVES: To examine parent perception of child behaviour problems and parenting stress in Hong Kong, and to assess the extent to which they are related to socio-demographic factors and the availability of social support. DESIGN: Cross-sectional survey by using a questionnaire. SETTING: Maternal and Child Health Centres, Hong Kong. PARTICIPANTS: Parents of children aged 4 years who were registered with Maternal and Child Health Centres and were living in Hong Kong between September 2002 and February 2003. MAIN OUTCOME MEASURES: Child behaviour problems and parenting stress. RESULTS: A total of 1009 questionnaires were returned giving a participation rate of 67.0%. About one tenth of parents were experiencing difficulties with their children's behaviour. Parenting stress and children's behaviour problems were associated with presence or absence of social support. Parenting stress was also associated with household income. CONCLUSIONS: The prevalence of child behaviour problems in Hong Kong is comparable with international figures. Intervention programmes should be targeted at parents who experience difficulties with their children's behaviour and parenting.

High-pressure injection injuries of the hand in a Chinese population.

We performed a retrospective review of 28 digits in 28 patients who suffered high-pressure injection injuries of the hand during the last 10 years. They were all men, with a mean age of 36 years. All were work injury and the injuries were classified into mild, moderate and severe and were either treated conservatively or surgically. There were seven patients with mild injuries and six of these were successfully treated by conservative methods. Sixteen patients had moderate injuries and all were successfully treated with repeated debridement and delayed direct closure. The index fingers of two severely injured patients were salvaged with digital artery flaps and the remainder of the involved fingers were amputated. The authors advocate proper identification of mild injuries to allow conservative treatment, the application of digital artery flaps for resurfacing large finger defects and have formulated a treatment protocol according to the severity of the injury.

Squamous cell carcinoma of the nail bed: three case reports.

Squamous cell carcinoma of the nail bed is rare, and the disease is often misdiagnosed as a benign condition. Digital amputation is often performed because of the delay in diagnosis and the involvement of the distal phalanx. Between March 1999 and March 2002, 3 patients presented to the Pamela Youde Nethersole Eastern Hospital, Hong Kong, with squamous cell carcinoma of the nail bed. Two of the patients underwent a digit-salvaging procedure-namely, wide local excision and flap coverage-and their functional outcome was satisfactory. The remaining patient received partial amputation of the thumb without significant functional loss. A high degree of suspicion is thus needed to detect squamous cell carcinoma of the nail bed; a biopsy of chronic recurrent nail bed lesions should be performed.

Distal fixation with Wagner revision stem in treating Vancouver type B2 periprosthetic femur fractures in geriatric patients.

Periprosthetic fractures around hip prostheses are difficult problems. We reviewed the results of treatment with Wagner revision stems in geriatric patients (> or = 65 years old) with Vancouver type B2 periprosthetic fractures. Over a 5-year period, 14 patients with Vancouver's type B2 periprosthetic fractures in the proximal femur were revised. The mean follow-up for these patients was 58.5 months (range, 36 to 64 months). The average age was 74.5 years (67 to 83 years). Twelve patients were available for assessment; all 12 reconstructions showed a stable prosthesis and solid fracture union. Seven patients had excellent outcome, 3 had a good outcome, and 2 had a poor outcome. Our series shows that the Wagner revision stem is a satisfactory prosthesis in revision of Vancouver type B2 periprosthetic fractures in geriatric patients.

Overexpression of muscle specific kinase increases the transcription and aggregation of acetylcholine receptors in Xenopus embryos.

Muscle specific kinase (MuSK) mediates agrin-induced acetylcholine receptor (AChR) aggregation on muscle membrane at the neuromuscular junction (NMJ). To examine whether MuSK enhances NMJ formation during embryonic development in vivo, the level of expression of MuSK was manipulated in Xenopus embryos and the functional consequence at the NMJ was assessed. We found that overexpression of MuSK enhanced the formation of NMJ by increasing the aggregation of AChRs at innervated regions in developing embryos. The area of AChR aggregation increased by approximately 2-fold in MuSK injected embryos during the critical stages of NMJ formation. Interestingly, overexpression of MuSK in Xenopus embryos was found to induce the level of AChR transcript. Deletion of the Kringle domain in the MuSK construct did not attenuate the observed induction of AChR transcription and aggregation. Taken together, our findings provide the first demonstration that increased level of MuSK expression in vivo significantly elevate the aggregation and transcription of AChR at the NMJ in developing Xenopus embryos.

Prognosis of acute pelvic fractures in elderly patients: retrospective study.

OBJECTIVE: To analyse the pattern of acute pelvic fractures, prognostic indicators, and intermediate-term functional outcome among elderly patients. DESIGN: Retrospective study. SETTING: Community-based hospital, Hong Kong. PATIENTS: Sixty patients older than 60 years who were admitted to hospital with acute pelvic fracture between 1 November 1993 and 31 December 1996. MAIN OUTCOME MEASURES: Review of medical records and X-ray assessment to determine the patients' demographic data, medical comorbidities, aetiology and mechanism of injury, associated injuries, and clinical outcome indicators such as complications, duration of hospital stay, ambulatory status, and 1- and 2-year mortality rates. RESULTS: The mean follow-up period was 29 months (range, 12 to 65 months). Eighty-seven percent of patients were women and the predominant fracture pattern was Tile A2. The leading cause of injury was low-energy fall injury (75%). The 1-year mortality rate was nearly 12%. Thirty-six percent of patients experienced a decline in ambulatory status. Twenty-five percent of superior rami fractures involved the low anterior column of the acetabulum. There was a high incidence of associated cardiovascular disorders. CONCLUSIONS: Pre-existing medical conditions and acetabular involvement are important adverse factors affecting postinjury ambulatory status. A significant decline in ambulatory status and a significant mortality rate at 1 year were found following pelvic fracture in elderly patients.

Expression of Eph receptors in skeletal muscle and their localization at the neuromuscular junction.

The participation of ephrins and Eph receptors in guiding motor axons during muscle innervation has been well documented, but little is known about their expression and functional significance in muscle at later developmental stages. Our present study investigates the expression and localization of Eph receptors and ephrins in skeletal muscle. Prominent expression of EphA4, EphA7, and ephrin-A ligands was detected in muscle during embryonic development. More importantly, both EphA4 and EphA7, as well as ephrin-A2, were localized at the neuromuscular junction (NMJ) of adult muscle. Despite their relative abundance, they were not localized at the synapses during embryonic stages. The concentration of EphA4, EphA7, and ephrin-A2 at the NMJ was observed at postnatal stages and the synaptic localization became prominent at later developmental stages. In addition, expression of Eph receptors was increased by neuregulin and after nerve injury. Furthermore, we demonstrated that overexpression of EphA4 led to tyrosine phosphorylation of the actin-binding protein cortactin and that EphA4 was coimmunoprecipitated with cortactin in muscle. Taken together, our findings indicate that EphA4 is associated with the actin cytoskeleton. Since actin cytoskeleton is critical to the formation and stability of NMJ, the present findings raise the intriguing possibility that Eph receptors may have a novel role in NMJ formation and/or maintenance.

The expression profiles of neurotrophins and their receptors in rat and chicken tissues during development.

Neurotrophic factors are target-derived proteins that promote the survival and differentiation of the innervating neurons. Increasing evidence indicate the involvement of these factors and receptors during the formation and maturation of the neuromuscular junction. To gain further insight on the expression pattern of these factors and receptors in developing spinal cord and skeletal muscle during the critical stages of synapse formation, a systematic study was performed with chicken and rat tissues using Northern blot analysis. The expression of all the neurotrophins was detected in skeletal muscle early in development, coincidental with the appearance of their corresponding receptors in the spinal cord. Taken together, the similar regulatory patterns observed in both rat and chicken tissues suggest that the potential roles of neurotrophins at the neuromuscular synapse are conserved throughout evolution.