Functional dissection of the dictyostelium discoideum dynamin B mitochondrial targeting sequence

Most mitochondrial proteins are nuclear encoded and synthesized in the cytosol with an N-terminal mitochondrial targeting sequence or presequence for subsequent import into mitochondria. Here, we describe the proteolytic processing and inner membrane potential-dependent translocation of a dynamin family member by the Dictyostelium discoideum mitochondrial import system. Our results show that the unusual D. discoideum dynamin B presequence is removed through a processing mechanism that is common for mitochondrial matrix proteins. We identified a minimal segment of the dynamin B presequence containing seven lysine residues. This 47-residue region is, in combination with consensus matrix protease cleavage sites, necessary and sufficient for mitochondrial targeting. The correct positioning of these lysine residues plays a critical role for the proper processing and mitochondrial import of dynamin B in D. discoideum. Fluorescent proteins tagged with the dynamin B presequence or presequence regions supporting mitochondrial import in D. discoideum are imported with similar efficiency into the mitochondrial matrix of mammalian cells, indicating that the basic mechanisms underlying mitochondrial protein import are highly conserved from amoebozoa to mammalia.

Topography and morphological anatomy of nutrient foramina in human metacarpal bones and their clinical implications

PURPOSE

To study the morphological and topographic anatomy of nutrient foramina and to determine the foraminal index of metacarpal bones.

MATERIALS AND METHODS

The study consisted of 438 unpaired, human metacarpal bones of unknown age and sex. Nutrient foramina in each of the bones were grossly identified in relation to their number and location. The foraminal index was calculated by applying the Hughes formula. A digital vernier caliper was used to perform the measurements.

RESULTS

Among our specimens, 93.1% of metacarpals had single foramen, 2% had double foramina, 0.3% of the bones had triple foramina and in 4.6% of cases the foramen was absent. The mean foraminal indexes of the 1st, 2nd, 3rd, 4th and 5th metacarpal were 60.1, 53, 43.1, 43.7 and 45.9 respectively.

CONCLUSION

It was observed that the morphology and topography of nutrient foramina vary among different metacarpals. In 1st and 2nd metacarpals, foramina were more common at the medial surface and in other metacarpals, mostly seen on the lateral surface. The knowledge about these foramina is important in certain surgical procedures to preserve the circulation. This data is important to the plastic surgeon for microvascular bone transfer surgeries.

Green and NIR sensitized luminescent nanophosphor: preparation, characterization and application

Luminescent nanophosphor of Er, Yb: Gd(2)O(3) has been synthesized by well known combustion synthesis. Along with strong UV-Vis upconversion emission, sensor for temperature and magnetic field, nano-heater etc., it can also be used as luminescent ink by dispersing the nanophosphor in aqueous polyvinyl alcohol solution. The stability of the ink has been found to depend strongly on the mixing process of the phosphor powder in the polymer solution. The X-ray diffraction results and TEM images with diffraction pattern show that the particles are in cubic phase of Gd(2)O(3) with particles of average size <40 nm. SEM images show flaky structure which makes it suitable for dispersing in PVA and useful for luminescent ink purposes on NIR excitation. The FT-IR and the thermal analysis support the presence of PVA. Upconversion and downconversion luminescence has also been observed with 532 nm excitation and energy transfer mechanism has been explained. The NIR pumping gives strong UC emission bands in red and green regions extending up to extreme UV (240 nm) in this host.

Range of motion of the metacarpophalangeal joint in rheumatoid patients, with and without a flexible joint replacement prosthesis, compared with normal subjects

BACKGROUND

The metacarpophalangeal is commonly affected by rheumatoid arthritis. This may lead to joint replacement with a flexible prosthesis. The aims of this study were to determine the effects of rheumatoid arthritis on joint motion and to determine whether joint replacement needs to restore the full range of motion.

METHODS

Three-dimensional motion analysis was used to measure the range of motion of the metacarpophalangeal joint in rheumatoid patients with and without a flexible silicone arthroplasty, when performing pinch and key grips, when making a fist and when spreading the fingers. The results were compared with those from younger and older normal subjects.

FINDINGS

There appeared to be a trend for a decrease in range of motion from younger normal to older normal to rheumatoid (no prosthesis) to rheumatoid (with prosthesis) subject groups. However, statistically different (p<0.05) results were only observed for some movements (mostly involved in making a fist), in some fingers and between some subject groups. The only exception to this apparent trend was in flexion/extension when spreading the fingers into abduction.

INTERPRETATION

Making a fist is the most sensitive simple measure of range of motion in the metacarpophalangeal joint. Successful replacement of the metacarpophalangeal joint in patients with rheumatoid arthritis need not restore the normal range of motion.

An in vitro evaluation of the anthelmintic activity of Hedychium spichatum rhizomes and Zingiber zerumbet rhizomes on the Pheritima Posthuma model: A comparative study

Ethanolic extracts of Hedychium spichatum rhizomes and Zingiber zerumbet rhizomes were taken for in vitro comparative studies on the anthelmintic activity against Pheritima posthuma. Different concentrations (25, 50, 100 mg/ml) of both the extracts were used for the activity. Varying albendazole concentrations (25, 50, 100 mg/ml) were used as a reference standard and normal saline (0.9% NaCl) was used for the control treatment. The results were expressed in terms of time in minutes to report the paralysis and time of death of the earthworms. The results obtained from the study indicate toward the anthelmintic activity, supporting folk use of both the plants when compared with the standard. The results also established that Z. zerumbet was a more potent candidature of as compared with H. spichatum.

Effects of Low Dose Vasopressin in Catecholamine Resistant Septic Shock

BACKGROUND

Septic shock commonly leads to death in critically ill patients. Severe hypotension resistant to conventional catecholamine leads to multiorgan failure. We studied the effectiveness of low dose vasopressin in resistant septic shock.

METHODS

Thirty critically ill patients with catecholamine resistant hypotension were included in the study. After adequate fluid resuscitation, infusion of norepinephrine and dobutamine was started. If the patient remained hypotensive, vasopressin was infused at a fixed rate of 0.04 unit/minute for 24 hours. Haemodynamic parameters and mortality rates were recorded.

RESULT

There was a significant improvement in systolic and mean arterial pressure within four hours of starting vasopressin. This improvement continued throughout the 24-hour period. In addition, it was possible to withdraw dopamine in all the patients and significantly reduce infusion rates of dobutamine and norepinephrine. No significant complication was noted.

CONCLUSION

Low dose vasopressin at the rate of 0.04 unit/minute is an effective vasopressor in adult patients with catecholamine resistant septic shock.

Extent of surgery in the management of phyllodes tumor of the breast: a retrospective multicenter study from India

INTRODUCTION

Phyllodes tumor (PT) is a rare tumor of the breast. Usually, difficulty in making preoperative diagnoses and unpredictable clinical outcome of this disease leads to inappropriate management. Till date, no definite conclusion regarding the appropriate surgical procedure can be drawn.

OBJECTIVES

The objective of this retrospective study is to study the clinicopathological correlation of phyllodes tumors in North-Central part of the India and also to evaluate efficacy of the various surgical options available for the management of phyllodes tumors of the breast.

MATERIALS AND METHODS

A retrospective study of 24 cases from the archives of department of surgery of three tertiary institutes of North-Central part of India. We reviewed the clinical, pathological features of this disease entity with a view to highlight relevant features. We also analyzed various surgical options done for primary as well as recurrent PT.

RESULTS

The breast masses in our study were particularly large. The mean size of the lump was 9.5 +/- 5.5 cm (range was 4.0-23 cm). Histopathological report was benign, borderline, and malignant PT in 62.4%, 20.8%, and 16.8% of the cases, respectively. Overall, 31 surgical procedures (24 in primary and 7 in recurrent) were performed. Simple lumpectomy, wide local excision and simple mastectomy were done in 25%, 27.4% and 27.4% of primary (non-recurrent) cases of PT, respectively. Modified radical mastectomy and simple mastectomy with LD flap reconstruction was done in 7.2% and 2.4% in primary cases, respectively in recurrent cases, simple mastectomy was done in four cases and modified radical mastectomy was done in one case. Overall, recurrence was seen in 29.2% of the cases. The median time for recurrence was 6 months (range 5.0-36 months). 90% (6/7) of recurrence occurred in lumpectomy patients.

CONCLUSION

The unpredictable behavior of histological types and the disputable results of particular surgical procedures have contributed to the controversies. The therapeutic issue is further compounded by an imprecise preoperative diagnosis. This study shows that wide local excision for benign and borderline and simple mastectomy with or without reconstruction for the malignant PT of the breast are acceptable best surgical options.

Small interfering RNAs inhibit infectious bursal disease virus replication in Vero cells

Small interfering RNA (siRNA) molecules are considered to be a promising antiviral therapeutics. This study was performed to analyze the application of siRNA against infectious bursal disease virus (IBDV) replication. Two siRNAs were designed to target common coding sequences of four IBDV proteins. Corresponding vectors were constructed to express anti-IBDV short hairpin RNAs (shRNA) that were tested for their antiviral effect in Vero cells. The results showed that expressed shRNA inhibited the virus replication to a significant extent (92%) as determined by the virus titration in cell culture. This outcome demonstrated the effectiveness of RNA interference (RNAi) based mechanism against the IBDV in vitro.