Absence of the Musculocutaneous Nerve and Associated Compensation by the Median Nerve

The musculocutaneous and median nerves frequently show variations from their normal course. The purpose of this paper is to report a rare variation, in which the right musculocutaneous nerve was absent. Consequently, the median nerve supplied motor innervation to the flexor compartment of the arm and sensory innervation to the lateral aspect of the forearm. The primary targets of this paper are orthopedic surgeons, anesthesiologists and radiologists. In cases of injuries to the upper limb, knowledge of these variations can assist them in avoiding misdiagnoses.

Triple band notch compact MIMO antenna with defected ground structure and split ring resonator for wideband applications

A triple band notch multiple-input-multiple-output (MIMO) antenna is designed and proposed with complementary-split-ring-resonators (CSRR) on upper side and defected ground structure on bottom portion of the FR4 substrate material. A square shaped radiating element with cone shaped microstrip line feeding is used in the current design to achieve 50-ohm impedance. A compact dimension of 36 × 22 × 1.6 mm is used to fit this model for portable communication devices. Split ring resonators are placed adjacent to the feed line to improve the gain and defected ground with stubs is placed to enhance the bandwidth characteristics. Proposed antenna has bandwidth ranging from 2 to18 GHz with notching at 5.2–5.8 GHz (WLAN), 11–12 GHz (Satellite Broadcasting) and 12.5–14.5 GHz (Aeronautical Radio Navigation). The envelope correlation coefficient (ECC) is less than 0.005 and mutual coupling is less than 15dB achieved. The prototyped antenna is providing peak realized gain of 5dB and maximum efficiency of 75% in the operating band. The results strongly support the applicability of current antenna model with band notching in wideband communications.

A morphological variant of anterior belly of digastric muscle: a cadaveric case report

Occurrence of accessory bellies of anterior belly of digastric muscle (ABD) in the submental region is not uncommon. However reporting of different pattern of accessory bellies is of tremendous clinical significance for head and neck surgeons, radiologists and plastic surgeons. Herein we report a rare asymmetrical variant of ABD in the suprahyoid region. Accessory bellies were observed on either side of midline. On the right side accessory belly had two segments; one segment extended between the lower part of the ABD and hyoid bone, other one extended between the digastric fossa of mandible to the body of hyoid bone. On the left side accessory belly extended between mylohyoid muscle and to the lower part of the ABD.Bangladesh Journal of Medical Science Vol.16(3) 2017 p.461-463

A South Indian cadaveric study on obturator neurovascular bundle with a special emphasis on high prevalence of 'venous corona mortis'

Surgical procedures in the pelvic region are very challenging because of the complex anatomy of this region. "Corona mortis" is a term used to describe retro-pubic anastomosis between the obturator and external iliac vessels. It is considered as a key structure as significant haemorrhage may occur if the vessels are cut accidentally during pelvic surgeries. Earlier studies have documented a high frequency of venous anastomosis compared to its arterial counterpart. The objective of our study was to document the prevalence of venous corona mortis in South Indian human adult cadaveric pelvises. We conducted this study on 73 cadaveric pelvic halves. Out of the 73 hemi pelvises, 36 were normal without any variations of the obturator vessels while 37 hemi pelvises (51%) showed the presence of abnormal obturator vessels which proves to be a very high incidence in terms of variations. Out of the 37 hemi pelvises, 25 (68%) showed the presence of 2 obturator veins, out of which 1 was normal and the other was an abnormal obturator vein. 8 hemi pelvises (22%) had only abnormal obturator vein. Most of the abnormal obturator veins drained into the external iliac vein, while two veins drained into inferior epigastric veins. Venous corona mortis is said to be frequently encountered during surgery and is considered to be as important as arterial corona mortis in its clinical implications. Individual evaluation of this risky anatomical structure should be done prior to any surgical interventions.

Downregulation of Ca2+ signalling proteins in cardiac hypertrophy

Calcium (Ca2+) signaling plays an essential role in several functions of cardiac myocytes. Transient rises and reductions of cytosolic Ca2+, permitted by the sarcoplasmic reticulum Ca2+ ATPase and other proteins, control each cycle of contraction and relaxation. Prolonged rises of cytosolic Ca2+ are involved in transcriptional activation, including the hypertrophy program. Furthermore, activation of transcriptional pathways produced by excitation of membrane receptors and involving Protein Kinases C and D, calcineurin, mitogen-activated protein kinases and glycogen synthase kinase 3b, generate competitive recruitment of transcriptional factors whereby Ca2+ signaling proteins are downregulated in cardiac hypertrophy. This imbalance leads to defects of muscle contraction (i.e., systole) and relaxation (i.e., diastole), and ultimately cardiac failure. Extensive experimentation on gene transfer and gene deletion is under way to clarify the role of Ca2+ signaling proteins in cardiac hypertrophy and failure, and to evaluate the possibility of gene therapy. On the other hand, the need for pharmacological agents directed to function or transcription/expression of Ca2+ signaling proteins is emphasized, considering their easier delivery and wide population targeting.

Pentatricopeptide repeat proteins and their emerging roles in plants

Several protein families with tandem repeat motifs play a very important role in plant development and defense. The pentatricopeptide repeat (PPR) protein family, one of the largest families, is the most perplexing one in plants. PPR proteins have been implicated in many crucial functions broadly involving organelle biogenesis and plant development. PPR motifs are degenerate motifs, each with 35-amino-acid sequences and are present in tandem arrays of 2-27 repeats per protein. Although PPR proteins are found in other eukaryotes, their large number is probably required in plants to meet the specific needs of organellar gene expression. The repeats of PPR proteins form a superhelical structure to bind a specific ligand, probably a single-stranded RNA molecule, and modulate its expression. Functional studies on different PPR proteins have revealed their role in organellar RNA processing, fertility restoration in CMS plants, embryogenesis, and plant development. Functional genomic techniques can help identify the diverse roles of the PPR family of proteins in nucleus-organelle interaction and in plant development.

Phenylephrine hypertrophy, Ca2+-ATPase (SERCA2), and Ca2+ signaling in neonatal rat cardiac myocytes

We endeavored to use a basic and well-controlled experimental system to characterize the extent and time sequence of sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) involvement in the development of cardiac hypertrophy, including transcription, protein expression, Ca(2+) transport, and cytoplasmic Ca(2+) signaling. To this end, hypertrophy of neonatal rat cardiac myocytes in culture was obtained after adrenergic activation with phenylephrine (PE). Micrographic assessment of myocyte size, rise of [(14)C]phenylalanine incorporation and total protein expression, and increased transcription of atrial natriuretic factor demonstrated unambiguously the occurrence of hypertrophy. An early and prominent feature of hypertrophy was a reduction of the SERCA2 transcript, as determined by RT-PCR with reference to a stable marker such as glyceraldehyde-3-phosphate dehydrogenase. Reduction of Ca(2+)-ATPase protein levels and Ca(2+) transport activity to approximately 50% of control values followed with some delay, evidently as a consequence of a primary effect on transcription. Cytosolic Ca(2+) signaling kinetics, measured with a Ca(2+)-sensitive dye after electrical stimuli, were significantly altered in hypertrophic myocytes. However, the effect of PE hypertrophy on cytosolic Ca(2+) signaling kinetics was less prominent than observed in myocytes subjected to drastic SERCA2 downregulation with small interfering RNA or inhibition with thapsigargin (10 nM). We conclude that SERCA2 undergoes significant downregulation after hypertrophic stimuli, possibly due to lack of SERCA gene involvement by the hypertrophy transcriptional program. The consequence of SERCA2 downregulation on Ca(2+) signaling is partially compensated by alternate Ca(2+) transport mechanisms. These alterations may contribute to a gradual onset of functional failure in long-term hypertrophy.

Multiple variations in the paired arteries of the abdominal aorta

Variations in the origin of arteries in the abdomen are very common. The arteries that show frequent variations include the celiac trunk, renal arteries, and gonadal arteries. We observed multiple variations in a 45-year-old male cadaver. The variations found on the left side were: one accessory renal artery, two testicular arteries, and middle suprarenal and inferior phrenic arteries that branched from the celiac trunk. On the right side, the inferior phrenic and middle suprarenal arteries arose from the right renal artery.