MRI of rotator cuff muscle atrophy in relation to glenohumeral joint incongruence in brachial plexus birth injury

Purpose: To evaluate rotator cuff muscles and the glenohumeral (GH) joint in brachial plexus birth injury (BPBI) using MRI and to determine whether any correlation exists between muscular abnormality and the development of glenoid dysplasia and GH joint incongruity. Materials and methods: Thirty-nine consecutive BPBI patients with internal rotation contracture or absent active external rotation of the shoulder joint were examined clinically and imaged with MRI. In the physical examination, passive external rotation was measured to evaluate internal rotation contracture. Both shoulders were imaged and the glenoscapular angle, percentage of humeral head anterior to the middle of the glenoid fossa (PHHA) and the greatest thickness of the subscapular, infraspinous and supraspinous muscles were measured. The muscle ratio between the affected side and the normal side was calculated to exclude age variation in the assessment of muscle atrophy. Results: All muscles of the rotator cuff were atrophic, with the subscapular and infraspinous muscles being most severely affected. A correlation was found between the percentage of humeral head anterior to the middle of the glenoid fossa (PHHA) and the extent of subscapular muscle atrophy (r_s=0.45, P=0.01), as well as between its ratio (r_s=0.5, P P=0.01). Severity of rotator cuff muscle atrophy correlated with increased glenoid retroversion and the degree of internal rotation contracture. Conclusions: Glenoid retroversion and subluxation of the humeral head are common in patients with BPBI. All rotator cuff muscles are atrophic, especially the subscapular muscle. Muscle atrophy due to neurogenic damage apparently results in an imbalance of the shoulder muscles and progressive retroversion and subluxation of the GH joint, which in turn lead to internal rotation contracture and deformation of the joint.     

Cigarette smoke-induced differential regulation of glutathione metabolism in bronchial epithelial cells is balanced by an antioxidant tetrapeptide UPF1

Airway epithelium is a principal target for inhaled oxidants like cigarette smoke, which induce epithelial injury and thereby provoke pathogenesis of chronic airway diseases. Alterations in airway epithelial glutathione (GSH) metabolism are central in causing a loss of reducing environment, however, data are scarce on epithelial cells from larger bronchi. We showed a transient depletion of intracellular GSH in human bronchial epithelial cells after exposure to cigarette smoke condensate (CSC), which later followed by a prolonged elevation. Of the GSH-regulating enzymes, CSC increased mRNA expression of both catalytic (GCLC) and modifier (GCLM) subunits of glutamate-cysteine ligase. UPF1, a tetrapeptide GSH analogue, 4-methoxy-l-tyrosinyl-γ-l-glutamyl-l-cysteinyl-glycine, known to possess a 50-fold higher hydroxyl radical scavenging efficiency than does GSH, normalized the intracellular GSH level in the human bronchial epithelial cells under oxidative stress caused by CSC. UPF1 restored the GCLM and GSH reductase mRNA levels, which were significantly augmented by CSC treatment, back to the level of untreated control cells, referring to a successful establishment of control by UPF1 upon the over-accumulation of GSH. Moreover, UPF1 showed a significantly more potent antioxidant capacity than did N-acetyl-l-cysteine (NAC) and, compared to NAC, demonstrated a better potential to assure the whole GSH homeostasis in human bronchial epithelial cells.The current study suggests that UPF1 is capable of maintaining intracellular GSH level under CSC-induced oxidative stress in bronchial epithelial cells via balanced control over GSH-regulating enzymes, reflecting an improved perception of cellular redox conditions and thereby warranting improved adjustment of GSH accumulation.     

Quantification of Clostridium difficile in antibiotic-associated-diarrhea patients

Comparing culture- and non-culture-based methods for quantifying Clostridium difficile in antibiotic-associated-diarrhea patients, we found that the real-time PCR method correlated well with quantitative culture and was more sensitive. A positive association between the population levels of C. difficile and the presence of its toxins was found.     

The function of the hand after operations for obstetric injuries to the brachial plexus

Hand function was evaluated in 105 patients who had been operated on in early infancy for brachial plexus birth palsy. The mean follow-up after surgery was for 13.4 years (5.0 to 31.5). Fine sensation, stereognosis, grip and pinch strength and the Raimondi scale were recorded. Fine sensation was normal in 34 of 49 patients (69%) with C5-6 injury, 15 of 31 (48%) with C5-7 and in 8 of 25 (32%) with total injury. Loss of protective sensation or absent sensation was noted in some palmar areas of the hand in 12 of 105 patients (11%). Normal stereognosis was recorded in 88 of the 105 patients (84%), whereas only 9 of the 105 (9%) had normal grip strength. The mean Raimondi scale scores were 4.57 (3 to 5) (C5-6), 4.26 (1 to 5) (C5-7) and 2.16 (0 to 5) in patients with total injury. The location of impaired sensation was related to the distribution of the root injury. Avulsion type of injury correlated with poor recovery of hand function.     

Long-term results of surgery for brachial plexus birth palsy

BACKGROUND: The long-term results of surgical treatment of brachial plexus birth palsy have not been reported. We present the findings of a nationwide study, with a minimum five-year follow-up, of the outcomes of surgery for brachial plexus birth palsy in Finland. METHODS: Of 1,717,057 newborns, 1706 with brachial plexus birth palsy requiring hospital treatment were registered in Finland between 1971 and 1997. Of these patients, 124 (7.3%) underwent surgery on the brachial plexus at a mean age of 2.8 months (range, 0.4 to 13.2 months). The most commonly performed surgical procedure was direct neurorrhaphy after neuroma resection. One hundred and twelve patients (90%) returned for a clinical and radiographic follow-up examination after a mean of 13.3 years. Activities of daily living were recorded on a questionnaire, and the affected limb was assessed with use of joint-specific functional measures. RESULTS: Two-thirds (63%) of the patients were satisfied with the functional outcome, although one-third of all patients needed help in activities of daily living. One-third of the patients, including all nine with a clavicular nonunion from the surgical approach, experienced pain in the affected limb. All except four patients used the hand of the unaffected limb as the dominant hand. Shoulder function was moderate, with a mean Mallet score of 3.0. Both elbow and hand function were good, with a mean score on the Gilbert elbow scale of 3 and a mean Raimondi hand score of 4. Incongruence of the glenohumeral joint was noted in sixteen (16%) of the ninety-nine patients in whom it was assessed, and incongruence of the radiohumeral joint was noted in twenty-one (21%). The extent of the brachial plexus injury was found to be strongly associated with the final shoulder, elbow, and hand function in a multivariate analysis. CONCLUSIONS: Following surgical treatment of brachial plexus birth palsy, substantial numbers of the patients continued to need help performing activities of daily living and had pain in the affected limb, with the pain due to a clavicular nonunion in one-fourth of the patients. The strongest prognostic factor predicting outcome appears to be the extent of the primary plexus injury.     

Transglutaminase inhibition protects against oxidative stress-induced neuronal death downstream of pathological ERK activation

Molecular deletion of transglutaminase 2 (TG2) has been shown to improve function and survival in a host of neurological conditions including stroke, Huntington's disease, and Parkinson's disease. However, unifying schemes by which these cross-linking or polyaminating enzymes participate broadly in neuronal death have yet to be presented. Unexpectedly, we found that in addition to TG2, TG1 gene expression level is significantly induced following stroke in vivo or due to oxidative stress in vitro. Forced expression of TG1 or TG2 proteins is sufficient to induce neuronal death in Rattus norvegicus cortical neurons in vitro. Accordingly, molecular deletion of TG2 alone is insufficient to protect Mus musculus neurons from oxidative death. By contrast, structurally diverse inhibitors used at concentrations that inhibit TG1 and TG2 simultaneously are neuroprotective. These small molecules inhibit increases in neuronal transamidating activity induced by oxidative stress; they also protect neurons downstream of pathological ERK activation when added well after the onset of the death stimulus. Together, these studies suggest that multiple TG isoforms, not only TG2, participate in oxidative stress-induced cell death signaling; and that isoform nonselective inhibitors of TG will be most efficacious in combating oxidative death in neurological disorders.     

Surveillance cultures in pediatric allogeneic hematopoietic stem cell transplantation

The value of surveillance cultures in predicting systemic infections and in guiding antimicrobial treatment is controversial. We investigated 57 pediatric allo‐SCTs between 2007 and 2009. ALL (34), AML (5), and severe aplastic anemia (4) were the largest patient groups. Conditioning was TBI‐based in 87% and 54% developed GVHD (21% grade III‐IV). Of the 2594 weekly colonization samples, 24% were positive (fecal bacteria 86%, fecal fungi 16%, Clostridium difficile 16%; throat bacteria 17% and throat fungi 4%). Enterobacteria and enterococci were the most common fecal findings, staphylococci and streptococci in the throat. Of the bacterial stool samples pretransplant, 74% (mostly enterococci) were resistant to our first‐line antibiotics (ceftazidime and cloxacillin). Candida species accounted for the majority of the fungal findings: 62% of the fecal and 78% in the throat. A total of 170 clinical infection episodes were recorded, and in 12 of these, the bacterial blood culture was positive. In 4/12 cases, the pathogen was detected in surveillance culture previously, leading to sensitivity and specificity of 33.3 and 47.4%, respectively. Positive predictive value of bacterial surveillance cultures was 0.9%. The antimicrobial treatment was changed in only five cases based on the surveillance culture results. Weekly surveillance cultures seldom provided clinical benefit and were not cost‐effective.     

Brain responds to another person's eye blinks in a natural setting—the more empathetic the viewer the stronger the responses

An observer's brain is known to respond to another person's small nonverbal signals, such as gaze shifts and eye blinks. Here we aimed to find out how an observer's brain reacts to a speaker's eye blinks in the presence of other audiovisual information. Magnetoencephalographic brain responses along with eye gaze were recorded from 13 adults who watched a video of a person telling a story. The video was presented first without sound (visual), then with sound (audiovisual), and finally the audio story was presented with a still‐frame picture on the screen (audio control). The viewers mainly gazed at the eye region of the speaker. Their saccades were suppressed at about 180 ms after the start of the speaker's blinks, a subsequent increase of saccade occurence to the base level, or higher, at around 340 ms. The suppression occurred in visual and audiovisual conditions but not during the control audio presentation. Prominent brain responses to blinks peaked in the viewer's occipital cortex at about 250 ms, with no differences in mean peak amplitudes or latencies between visual and audiovisual conditions. During the audiovisual, but not visual‐only, presentation, the responses were the stronger the more empathetic the subject was according to the Empathic Concern score of the Interpersonal Reactivity Index questionnaire (Spearman's rank correlation, 0.73). The other person's eye blinks, nonverbal signs that often go unnoticed, thus elicited clear brain responses even in the presence of attention‐attracting audiovisual information from the narrative, with stronger responses in people with higher empathy scores.