Split flexor carpi radialis muscle

A detailed anatomic and intramuscular neural staining study in 22 human and 5 monkey upper limbs revealed that the flexor carpi radialis can be raised on its proximal neurovascular pedicle and that the muscle can be split along its tendon into two independently functioning neuromuscular compartments, each with its own nerve and blood supply. A study of the muscle architecture in the human specimens found the radial compartment to have significantly longer fiber length and a larger physiologic cross-sectional area than the ulnar compartment. Independence of function of each compartment was demonstrated in electrical stimulation studies in six monkeys (Macaca fascicularis), but no significant difference was noted in the peak isometric load between the two compartments (p = 0.68) in the monkey. The extra functioning muscle units become important in local transfers for restoring function in multiple nerve palsies as in Hansen's disease, severe traumatic loss of muscle in crush injuries and compartment syndromes, and after wide resection in infective and neoplastic conditions in the forearm and hand.     

Follicular variant of papillary carcinoma of the thyroid. A cytologic study of 15 cases

OBJECTIVE: To study the cytologic findings of follicular variant of papillary thyroid carcinoma (FVPTC) and to compare them with the cytologic findings on other thyroid lesions. STUDY DESIGN: The study group consisted of aspirate smears from 15 cases of histologically proven FVPTC. The control group consisted of 152 cases, including adenomatous colloid goiter (70), usual papillary carcinoma (40), follicular adenoma (30), Hürthle cell neoplasm (7) and medullary carcinoma (5). RESULTS: The smears of FVPTC revealed numerous colloid balls in the background, multilayered microfollicles (rosettes), numerous nuclear grooves and inclusions in the monolayer sheets of follicular cells, very rare giant cells, absence of calcification and papillary clusters. Rosettelike microfollicles and numerous colloid balls were not seen in the control group. CONCLUSION: The combination of numerous colloid balls and rosettelike microfollicles was frequently seen in FVPTC. This combination was not observed in the control group.     

Den shifting by wolves in semi-wild landscapes in the Deccan Plateau, Maharashtra, India

Reproductive success is crucial for the survival and persistence of any species. The Deccan Biogeographic Zone of India is the stronghold of a population of the Indian wolf Canis lupus pallipes . Gaining a better understanding of the den-use pattern of wolves in different areas in this zone is thus vital for their conservation and management. The wolves excavated multiple dens in our study sites and kept shifting their litters among them. Major disturbance factors around denning sites were active stone quarries, traffic, crop harvesting and livestock movement. One wolf pack used 14 dens in four breeding seasons. Discriminant function analysis indicated that den shifting by wolves was not entirely governed by disturbance levels at den sites. Increasing age of pups was one of the main factors associated with den shifting rather than the magnitude of disturbance ( χ ²=34.26, d.f.=12, P <0.001). Tolerance to disturbance around dens during the early stages of pup development was negatively correlated ( r =−0.519, P <0.05) with availability of water and age of pups ( r =−0.613, P <0.01). Excavation of multiple dens by wolves was apparently related to den shifting, which seemingly is a survival strategy of wolves in these semi-wild human-dominated landscapes in the Deccan Biogeographic Zone. Principal components analysis indicated that during the initial stages of pup development, nature of the land, den orientation and distance of the den from roads were important cues in addition to age category of pups for den shifting. The analysis also suggested that factors such as distance of the new den where pups are to be transferred, distance from water source and availability of fox Vulpes bengalensis holes for den use were also important.     

Callus culture and an unconventional pattern of sporophyte regeneration in Drynaria quercifolia—A medicinal fern

Summary Callus induction and regeneration studies were carried out on a medicinal fern, Drynaria quercifolia native to Asian countries. It is a seasonal fern that regenerates only during the monsoons. Callus was induced on Knop’s (1865) medium supplemented with 20 gl⁻¹ sucrose, 8gl⁻¹ agar, and either 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), 4-amino-3,5,6-trichloropicolinic acid (picloram), or indole-3-butyric acid at different concentrations. Morphogenetic callus obtained on 5 mgl⁻¹ 2,4,5-T was subcultured onto solid and liquid media (shaken flask and discontinuously stirred bioreactor cultures) for callus proliferation and regeneration studies. A significant amount of sporophyte regeneration was observed on solid medium containing 10 mgl⁻¹ 6-(δ, δ-dimethylallylamino) purine (2iP). Sporophyte regeneration from callus followed an atypical pattern of development. Leafy structures of single-cell thickness with a microrhizome were formed as sporophyte initials. Prolonged cultures of these structures resulted in the formation of juvenile sporophytes in vitro. The use of liquid media resulted in increased biomass in culture. The present study is the first report of a successful system for callus production and regeneration of sporophytes from leafy structures in ferns. The method can be successfully applied for generation of biomass of D. quercifolia, throughout the year.     

Synthesis of functional human immunodeficiency virus tat protein in baculovirus as determined by a cell-cell fusion assay.

The human immunodeficiency virus tat protein is a strong trans-activator of the expression of mRNAs originating from the viral long terminal repeat. We have expressed the first 72 amino acids (coding exon 1) of this protein in eucaryotic Spodoptera frugiperda SF9 cells by using a baculovirus vector, Autographa californica nuclear polyhedrosis virus. We show that the baculovirus vector stably produced the 72-amino-acid form of the tat protein but was unable to stably synthesize a larger 101-amino-acid full-length version of the same polypeptide. The 72-amino-acid tat protein, when introduced into mammalian fibroblasts by using a cell-cell fusion technique, functionally trans-activated the expression of the human immunodeficiency virus long terminal repeat.     

Physical aspects and cytoplasmic distribution of messenger RNA in mouse kidney.

As a prerequisite to examining mRNA metabolism in compensatory renal hypertrophy, polyadenylated RNA has been purified from normal mouse kidney polysomal RNA by selection on oligo(dT)-cellulose. Poly(A)-containing RNA dissociated from polysomes by treatment with 10 mM EDTA and sedimented heterogeneously in dodecyl sulfate-containing sucrose density gradients with a mean sedimentation coefficient of 20 S. Poly(A) derived from this RNA migrated at the rate of 6-7 S RNA in dodecyl sulfate-containing 10% polyacrylamide gels. Coelectrophoresis of poly(A) labeled for 90 min with poly(A) labeled for 24 h indicated the long-term labeled poly(A) migrated faster than pulse-labeled material. Twenty percent of the cytoplasmic poly(A)-containing mRNA was not associated with the polysomes, but sedimented in the 40-80 S region (post-polysomal). Messenger RNA from the post-polysomal region had sedimentation properties similar to those of mRNA prepared from polysomes indicating post-polysomal mRNA was not degraded polysomal mRNA. Preliminary labeling experiments indicated a rapid equilibration of radioactivity between the polysomal and post-polysomal mRNA populations, suggesting the post-polysomal mRNA may consist of mRNA in transit to the polysomes.     

Analysis of the Escherichia coli glycogen gene cluster suggests that catabolic enzymes are encoded among the biosynthetic genes

The nucleotide sequences of the Escherichia coli genome between the glycogen biosynthetic genes glgB and glgC, and 1170 bp of DNA which follows glgA have been determined. The region between glgB and glgC contains an open reading frame (ORF) of 1521 bp which we call glgX. This ORF is capable of coding for an M_r 56 684 protein. The deduced amino acid (aa) sequence for the putative product shows significant similarity to the E. coli glycogen branching enzyme, and to several different glucan hydrolases and transferases. The regions of sequence similarity include residues which have been reported to be involved in substrate binding and catalysis by taka-amylase. This suggests that the proposed product may catalyze hydrolysis or glycosyltransferase reactions. The cloned region which follows glgA contains an incomplete ORF (1149 bp), glgY, which appears to encode 383 aa of the N terminus of glycogen phosphorylase, based upon sequence similarity with the enzyme from rabbit muscle (47% identical aa residues) and with maltodextrin phosphorylase from E. coli (37% identical aa residues). Results suggest that neither ORF is required for glycogen biosynthesis. The localization of glycogen biosynthetic and degradative genes together in a cluster may facilitate the regulation of these systems in vivo.