NAP protects against cyanide-related microtubule destruction

The peptide NAP (NAPVSIPQ) was shown to protect neurons against a wide variety of insults. Particularly, NAP was shown to be neuroprotective in vitro against cyanide in hippocampal cultures and against oxygen-glucose deprivation in hippocampal and cortical neuronal cultures. Cyanide causes energy depletion in the cell and destroys the cytoskeleton, and NAP has been shown before to protect the microtubule cytoskeleton. The current study explored the effect of NAP on cyanide-induced microtubule destruction in cerebral cortical cultures. Sodium cyanide (6.8 mM) reduced the number of neurons containing intact microtubules as identified by bIII-tubulin immunostaining. When sodium cyanide was added together with NAP (10⁻¹⁴–10⁻¹² M), complete protection was observed. Although the primary site of action of cyanide is considered to be the mitochondria, the current results involve microtubule destruction by cyanide toxicity that is completely reversed by NAP treatment.     

Diagnostic efficiency of Sestamibi gammagraphy and Doppler sonography in the preoperative assessment of breast lesions

Introduction It would be desirable to have preoperative methods that allow an adequate selection of patients with breast lesions to rule out breast cancer: The aim of the present study is to evaluate the efficiency of preoperative Sestamibi gammagraphy and Doppler sonography regarding the differential diagnosis of malignancy in breast lesions. Material and methods A prospective observational study was conducted on 88 consecutive patients with breast lesions. All the patients underwent preoperative Doppler sonogrpahy with an echo-enhancing agent and Sestamibi gammagraphy. All the patients had histopathological study of the surgical specimen to compare with the result of the preoperative techniques. These comparations were done both for the overall series and separately for palpable and non-palpable lesions. Results In the overall series results, both tests separately and the two combined, are related significantly to the malignant histological diagnosis (p<0.001). In palpable lesions, there is a considerable increase in sensitivity, and especially in specificity, attaining 100%, with the combination of both tests. In non-palpable lesions, a relationship was only found between the results of the Sestamibi gammagraphy and the malignant histological diagnosis (93.3%; p<0.05). Conclusions Sestamibi gammagraphy and Doppler sonography are two efficient exploratory techniques in the preoperative assessment of malignancy in breast lesions, especially for palpable lesions, and this efficiency is greater when they are combined.     

Surgical instruments (I). An introduction to surgical instruments

In surgical wards, the variety and increasing complexity of techniques used, together with the high number of materials and instruments employed, demands that professionals who join these wards have a specific professional development related to instruments and techniques. In this short series of articles, the author shall present distinct manners to gain knowledge about instruments in such a way that at the end of this series, professionals who are interested will have a guide to help them acquire a deep understanding of surgical instruments, their common usage and their specialized characteristics. A bibliography will be included with the last article.     

Receptors for VIP and PACAP in guinea pig cerebral cortex

Receptors for vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) in guinea pig cerebral cortex were characterized by (1) radioreceptor binding of ¹²⁵I-labeled VIP (human/rat/porcine), and (2) cyclic AMP (cAMP) formation. Saturation analysis of ¹²⁵I-VIP binding to membranes of guinea pig cerebral cortex resulted in a linear Scatchard plot, suggesting the presence of a single class of high-affinity receptor-binding sites, with a Kd of 0.63 nM and a Bmax of 77 fmol/mg protein. Various peptides from the PACAP/VIP/secretin family displaced the specific binding of ¹²⁵I-VIP to guinea pig cerebrum with the relative rank order of potency: chicken VIP (cVIP) ≥ PACP38 ∼ PACAP27 ∼ guinea pig VIP (gpVIP) ≥ mammalian (human/rat/porcine) VIP (mVIP) > peptide histidine-methionine (PHM) > peptide histidine-isoleucine (PHI) > secretin. Analysis of the competition curves revealed displacement of ¹²⁵I-VIP from high- and lower-affinity binding sites, with IC50 values in the picomolar and the nanomolar range, respectively. About 70% of the specific ¹²⁵I-VIP-binding sites in guinea pig cerebral cortex were sensitive to Gpp(NH)p, a nonhydrolyzable analog of GTP. Pituitary adenylate cyclase-activating polypeptide 38 (PACAP38), PACAP27, cVIP, gpVIP, mVIP, PHM, and PHI stimulated cAMP production in [³H]adenine-prelabeled slices of guinea pig cerebral cortex in a concentration-dependent manner. Of the tested peptides, the most effective were PACAP38 and PACAP27, which at a 1 μM concentration produced a 17- to 19-fold rise in cAMP synthesis, increasing the nucleotide production to approx 11% conversion above the control value. The three forms of VIP (cVIP, mVIP, and gpVIP) at the highest concentration used, i.e., 3 μM, produced net increases in cAMP production in the range of 8–9% conversion, whereas 5 μM PHM and PHI, by, respectively, 6.7% and 4.9% conversion. It is concluded that cerebral cortex of guinea pig contains VPAC- type receptors positively linked to cAMP formation. In addition, the observed stronger action of PACAP (both PACAP38 and PACAP27), when compared to any form of VIP, on cAMP production in this tissue, suggests its interaction with both PAC1 and VPAC receptors.     

Pneumatic tourniquets

Pneumatic tourniquets have proven to be a great help in surgery on limbs, on a wide range of operations involving bone surfaces or in delicate operations on hands and feet. Their correct use reduces the amount of tissue exposed, lowers the doses of anaesthetics required, limits the administration of blood products, but their use is not always possible. The author describes the evolution of these devices, highlighting their application and aspects related to patient care.