Neuromuscular Partitioning of Subscapularis Based on Intramuscular Nerve Distribution Patterns: Implications for Botulinum Toxin Injections

Subscapularis muscle spasticity is commonly treated with botulinum toxin injections; however, there are challenges in determining optimal injection sites within the muscle. The purpose of this study was to document the intramuscular innervation patterns of the subscapularis (1) to determine how the muscle is neuromuscularly partitioned and (2) to identify a strategy for botulinum toxin injection based on neuromuscular partitioning. In 50 formalin-embalmed cadaveric specimens, the extramuscular and intramuscular innervation was (1) serially dissected, digitized, and reconstructed in 3 dimensions (n=7); or (2) serially dissected and photographed (n=43). Intramuscular innervation patterns were compared among specimens to identify neuromuscular partitions. Variation was observed in the number (2–5) and origin of extramuscular nerve branches to the subscapularis. Despite variation in extramuscular innervation, the intramuscular innervation was consistent. Based on intramuscular innervation patterns, the subscapularis had 3 neuromuscular partitions (superior, middle, inferior) in 78% of specimens, and 2 partitions (superior, inferior) in 22% of specimens. The superior and middle partitions were most commonly innervated by branch(es) from the posterior cord, and the inferior partition by branch(es) from the axillary nerve. Injection of botulinum toxin into each partition may help to optimize results in the treatment of shoulder spasticity, and may be achieved by a combination of medial and inferior approaches. Clinical studies are required to determine whether the combination approach is more effective than any single approach and whether the number of partitions injected correlates with clinical outcomes.     

Radiation-Induced in Vitro Phototoxic Potential of Some Fluoroquinolones

Photosensitizing drugs that can damage cellular biomolecules is a matter of concern. Lomefloxacin, norfloxacin, ofloxacin, and enoxacin (broad-spectrum antibiotics of fluoroquinolone group) are used for the treatment of Gram-positive and Gram-negative bacterial infections. Phototoxicity and possible mechanism of their action was assessed under the exposure of ambient levels of UV-A, UV-B, and sunlight at a concentration generally used in the treatment of various diseases. Singlet oxygen (¹O₂), superoxide anion radical (O₂^·?) generation, DNA damage, and lipid peroxidation in human blood were studied. All the fluoroquinolones tested in this study produced ¹O₂ and O₂^·? under exposure to UV-A, UV-B, and sunlight depending on the concentrations (0 to 60 μg/mL) of the drugs. Enoxacin showed a higher yield of ¹O₂ and O₂^·? than other drugs. These materials also degraded deoxyguanosine and induced lipid peroxidation in vitro under exposure to UV-A, UV-B, and sunlight (depending on the dose of radiation). The formation of the reactive oxygen species (ROS) by the photoexcited drugs may be considered as a possible mechanism of their action.     

Crypto-Giardia antigen rapid test versus conventional modified Ziehl-Neelsen acid fast staining method for diagnosis of cryptosporidiosis

ObjectiveTo evaluate the validity of Crypto-Giardia antigen rapid test (CA-RT) in comparison with the conventional modified Ziehl-Neelsen acid fast (MZN-AF) staining method for the diagnosis of cryptosporidiosis.MethodsFifteen preserved stool samples from previously confirmed infections were used as positive controls and 40 stool samples from healthy people were used as negative control. A total of 85 stool samples were collected from suspected patients with cryptosporidiosis over 6 months during the period from January till June, 2011. The study was conducted in the department of parasitology, central laboratory, Alnoor Specialist Hospital, Makkah, Saudi Arabia. All samples were subjected to CA-RT and conventional MZN-AF staining method. Validation parameters including sensitivity (SN), specificity (SP), accuracy index (AI), positive predictive value (PPV), and negative predictive value (NPV) were evaluated for both tests.ResultsOut of 15 positive controls, CA-RT detected 13 (86.7%) while MZN-AF detected 11(73.3%) positive cases. However, CA-RT detected no positive case in 40 normal controls but MZN-AF detected 2(5%) as positive cases. Based on the results, the SN, SP, AI, PPV and NPV were high in CA-RT than MZN-AF staining method, ie., 86.7% vs. 73.3%, 100% vs. 95%, 96.4% vs. 89.1%, 100% vs. 84.6% and 95.2% vs. 90.5%, respectively. Out of a total of 85 suspected specimens, CA-RT detected 7(8.2%) but MZN-AF detected 6(7.1%) cases as positive.ConclusionsCA-RT immunoassay is more valid and reliable than MZN-AF staining method.     

A novel homozygous missense variant in NECTIN4 (PVRL4) causing ectodermal dysplasia cutaneous syndactyly syndrome

Ectodermal dysplasia syndactyly syndrome 1 (EDSS1) is a rare form of ectodermal dysplasia including anomalies of hair, nails, and teeth along with bilateral cutaneous syndactyly of hands and feet. In the present report, we performed a clinical and genetic characterization of a consanguineous Pakistani family with four individuals affected by EDSS1. We performed exome sequencing using DNA of one affected individual. Exome data analysis identified a novel homozygous missense variant (c.242T>C; p.(Leu81Pro)) in NECTIN4 (PVRL4). Sanger sequencing validated this variant and confirmed its cosegregation with the disease phenotype in the family members. Thus, our report adds a novel variant to the NECTIN4 mutation spectrum and contributes to the NECTIN4‐related clinical characterization.     

Standardization of pathology laboratories in Pakistan: Problems and prospects

A Total Quality Management System with an internationally recognized accreditation process is the only guarantee of a reliable pathology service. However in a developing country like Pakistan nearly 90% of labs are small and without adequate physical and man power infrastructures. A modified plan may have to be tailored for them. A two tier system has been formulated. Accreditation based on ISO 15189 is to be introduced on voluntary basis. The labs which do not qualify for international standardization would be brought into quality net through a registration process. All such labs will be initiated into a simplified quality management system. Participation in proficiency testing program will be mandatory. They will be provided education and training to become eligible for accreditation. It is hoped that this simplified system will provide an impetus for evolving a workable and comprehensive mechanism through which pathology laboratories in the country will be able to offer better and more reliable services.