Knee muscle activity during gait in patients with anterior cruciate ligament injury: a systematic review of electromyographic studies

Purpose

This review compared knee muscle activity between ACL-deficient (ACLD) patients and healthy controls during gait, to find out whether the available electromyography (EMG) studies support Quadriceps (Q-ceps) inhibition or hamstring facilitation during gait in ACLD patients.

Method

A systematic review was conducted to retrieve the EMG studies of knee muscles during gait in ACLD patients. Cochrane library, PubMed, Medline, Ovid, CINAHL and Science Direct databases were searched entries from 1995 through October 2014 using the terms “anterior cruciate ligament” OR “ACL”, “electromyography” Or “EMG” “gait” Or “walking”. Articles that assessed subjects with ACL rupture that used surface EMG to assess the knee muscle activity were included. The quality of the included papers was assessed using the Critical Appraisal Skills Programme tool for observational studies.

Result

In total, 13 studies met the inclusion criteria. Seven studies consistently found no significant difference in magnitude of activity or timing of Q-ceps muscle between the chronic ACLD patients and control subjects. Two studies on acute ACLD patients and three studies on ACLD patients with unstable knee found the significantly reduced Q-ceps activity compared to control subjects. Six studies showed the significantly greater hamstring activity, and three studies found prolonged duration of activity in ACLD patients compared to the control subjects.

Conclusion

This review highlighted that the results of the studies are in favour of increased hamstring muscular activity. However, decreased Q-ceps activation exists in the acute stage and in ACLD patients that experience knee instability (non-copers).

Level of evidence

III.

     

D-penicillamine, a potent melanogenesis inhibitor, lacks any depigmenting effect on black guinea pig skin: the first randomized, evaluator-blinded, vehicle-controlled, in vivo study

D-penicillamine is a melanogenesis inhibitor. This in vivo study on ten black guinea pigs using a 5% D-penicillamine ointment showed its lack of any skin-lightening effect. The potential reasons for this ineffectiveness are discussed in the paper, which could be very helpful for researchers exploring new skin-lightening agents.     

Diesel exhaust particles and allergenicity of pollen grains of Lilium martagon

Diesel exhaust particles are considered as the most important parts of air pollutants. Diesel exhaust particles have been shown to express both adjuvant activity for sensitization against common allergens and enhancing effects on allergic symptoms in sensitized individuals. In this research, pollen grains of Lilium martagon that are known as a non-allergic substance were collected and exposed to DEP 5 and 10 days. The allergy potency of different pollen extracts were compared by means of skin test, as well as analyses blood eosinophil numbers and IgE levels in the treated animals. Normal and DEP-exposed pollen grains were examined by scanning electron microscopy. Pollen extracts were also studied by SDS-PAGE for DEP-induced changes in protein profiles. Allergic bands were also studied and checked by using immunoblotting method. The results of the investigated allergy tests showed that DEP-exposed pollen grains are effective in inducing allergic symptoms. According to our microscopic observations, organic substances that exist in the DEP, mediate agglomeration of particles on the pollen surface. In appropriate conditions, water-soluble components of DEP may induce changes that affect the release of pollen proteins. SDS-PAGE showed protein profiles of pollen grains were changed and some new bands appeared in DEP-exposed pollen grains. Immunoblotting studies showed a new band in DEP-exposed pollen grains that react strongly with anti-IgE, but there is no allergenic band in normal pollen grains. On the other hand, diesel exhaust particles can carry pollen allergen molecules, induce new proteins (allergens), and also act as adjuvant for allergens.     

Prevalence,incidence, and residual risk of human immunodeficiency virus and hepatitis C virus infections among United States blood donors since the introduction of nucleic acid testing

BACKGROUND: Nucleic acid testing (NAT) for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) was introduced for blood donation screening in the United States in 1999. This study analyzes temporal trends of these two infections since NAT introduction. STUDY DESIGN AND METHODS: Donation data from 1999 to 2008 were analyzed; each donation was tested for antibodies and viral RNA for HIV and HCV. Incidence for first‐time (FT) donors was derived by multiplying that among repeat (RP) donors by the ratio of NAT yield rates between FT and RP donors. Incidence for all donors was the weighted mean based on percentage of FT and RP donors. Residual risk (RR) was determined using the window‐period model. RESULTS: During the 10‐year period approximately 66 million donations were screened with 32 HIV (1:2 million) and 244 HCV (1:270,000) NAT yield donations identified. HCV prevalence among FT donors decreased by 53% for 2008 compared to 1999. HIV and HCV incidence among RP donors increased in 2007 through 2008 compared to 2005 through 2006. During 2007 through 2008, HIV incidence was 3.1 per 10⁵ person‐years (py), with an RR estimate of 0.68 per 10⁶ (1:1,467,000) donations; HCV incidence was 5.1 per 10⁵ py, with an RR estimate of 0.87 per 10⁶ (1:1,149,000). The increase in HIV incidence was primarily among 16‐ to 19‐year‐old, male African American donors and that in HCV was primarily among Caucasian donors of 50 or more years. Donors from the Southern United States had higher incidence rates. CONCLUSION: HCV prevalence decreased significantly since NAT introduction. The increase in HIV and HCV incidence in 2007 through 2008 warrants continued monitoring and investigation.     

Cutaneous necrotic lesion: A wonderful delay adverse effect of interferon beta‐1b injection for multiple sclerosis treatment

Multiple sclerosis (MS) is a chronic and inflammatory autoimmune disease. These patients may manifest severe inflammatory cutaneous reactions after using interferon beta‐1b. This article describes a 55‐year‐old man with severe injection site reactions after 10 years administration of interferon beta‐1b. The biopsy specimens revealed skin and subcutaneous tissue necrosis. Histologic evaluation revealed nonspecific inflammatory reactions with no evidence of vasculitis or granulomatous reactions. Based on clinical and pathological findings, the diagnosis of skin and soft tissue necrosis due to interferon injection was given. The injection of interferon beta‐1b in the affected areas was stopped, and the patient's clinical condition improved by wound care. This report is aimed to increase awareness about severe adverse skin reactions, which may infrequently occur with subcutaneous interferon beta‐1b injection after several years. Early diagnosis of this reaction can help to prevent associated complications.