[Right heart support during coronary artery bypass grafting without cardiopulmonary bypass]

BACKGROUND AND OBJECTIVES

Exposure of lateral and inferior coronary vessels during off-pump coronary artery bypass grafting may cause significant hemodynamic compromise due to right ventricular compression when tilting the heart. Some new right ventricular assistance devices have been developed in order to avoid this problem but only a few series have been published. A preliminary experience with a right heart circulatory support system is reported.

METHODS

A total of eight patients underwent off-pump coronary artery bypass grafting using a right heart support device. Technical procedure and clinical outcome are analyzed.

RESULTS

The right heart circulatory support device insertion and management were performed without any complication. A total of 21 distal coronary anastomoses were completed. They were located on the anterior descending artery(8), circumflex branches(6), diagonal branches(2), posterior descending artery(3) and right coronary artery(2). The right ventricular support device delivered flow at a medium rate of 2.2 L/min, providing hemodynamic stability when tilting the heart and exposing the coronary arteries.

CONCLUSIONS

The use of right heart support devices is a simple and low risk procedure which may facilitate surgical anastomoses on lateral and inferior epicardial vessels during off-pump coronary artery surgery.

[Characterization of the expression and function of SigM an ECF sigma factor in mycobacteria]

The survival of M. tuberculosis within the macrophage depends on its ability to respond to oxidative stress, and the ECF subfamily of sigma factors likely play an important role. We studied SigM, a sigma factor whose gene is located near the origin of DNA replication. In both M. smegmatis and M. bovis BCG, the expression of sigM was induced at high temperature and in stationary phase. Mutants of M. smegmatis without an intact sigM were defective for survival in oxidative stress and also for the induction of thioredoxin reductase activity in oxidative stress. The thioredoxin system reduces disulfide bonds that are formed in oxidative stress. SigM thus appears to regulate thioredoxins and forms part of the bacteria's complex protective responses.

Personal-computer-based system for three-dimensional anatomic-physiological correlations during stereotactic and functional neurosurgery

This paper describes the automatic three-dimensional (3D) graphic possibilities that are supplied by the Neurosurgical Deep Recording System (NDRS) to facilitate anatomic-physiological targeting during stereotactic and functional neurosurgery using depth recording. This software has been developed to substitute the complex electronic equipment ordinarily used for deep brain electrical recording, display and processing by a personal computer. It may also help to improve on-line graphic analysis, automatic management of the recorded information and flexibility to implement different forms of signal analysis. It can automatically show a 2D or 3D representation of the electrode track, with the electrophysiological findings superimposed as well as the corresponding sagittal, coronal and axial views of a brain atlas using automatic scaling. The NDRS has already successfully been applied during more than 300 neurosurgeries in Spain and Cuba, enabling improved targeting accuracy and safety.

Plasma cell gingivitis

Plasma cell gingivitis (PCG), an infrequent benign inflammatory condition of unknown etiology, is a type of plasma cell orificial mucositis, which includes a wide spectrum of conditions. We present the case of a 13-year-old girl who had PCG with an erythematous congestive plaque on the anterior maxillary gingiva for 4 years. Occasionally, the lesion became increasingly swollen and painful and bled. Results of a histopathologic examination showed dense plasmacytic infiltrate in the dermis, affecting the dermoepidermal border, with immunohistochemical positivity in the K and A light chains and vascular proliferation. "Lozenge" keratinocytes, "watery" spongiosis, and exocytosis were seen in the epidermis. Laboratory analysis showed notably low levels of both serum IgA and secretory IgA. We consider whether secretory IgA at low levels has an important etiopathogenic role favoring the development of localized subclinical repetitive infections that could lead to chronic PCG.

[Clinical value of positron emission tomography with F-18-FDG in the follow up of patients with cancer of the ovary]

BACKGROUND

Positron emission tomography with fluor-18-deoxyglucose (PET-FDG) is an efficient technique for the detection of tumoural tissue. The aim of the paper is to evaluate the PET-FDG in the diagnosis of residual disease or relapse in patients with cancer of the ovary.

METHODS

A total of 24 patients, diagnosed and treated for cancer of the ovary with surgery and subsequent chemotherapy, were included. With 12 patients the study was carried out prior to second-look surgery, and with the other 12 after objectivising an increase of the tumoural marker in the follow up. Abdominal-pelvic CAT, determination of the seric levels of CA-125 and PET-FDG of thorax, abdomen and pelvis were carried out on all patients. The PET-FDG was evaluated in a qualitative way through the visual study of the images, and quantitatively through the SUV or standard uptake value. The definitive diagnosis was confirmed through an anatomopathological study in 13 cases and through clinical follow up in the rest with an average of 11.2+/-5.4 months (range 6-24).

RESULTS

A CA-125 value higher than 35 UI/ml was considered positive, obtaining a sensitivity of 77% and a specificity of 100%. The sensitivity of the CAT was 23% and the specificity 91%. With the FDG-PET sensitivity was 92% and the specificity 90%. A SUV value >or= 3 was considered pathological, obtaining the same results as with the visual evaluation. The FDG-PET was positive in 5 patients with non-conclusive CAT, 4 with negative CAT and 2 with negative CA-125.

CONCLUSION

These preliminary results suggest that the FDG-PET could be useful in the detection of disease in the follow up of patients treated for cancer of the ovary. The FDG-PET could be efficient in the differentiation between residual disease or recurrence, as opposed to sequels to the treatment, when the CAT is not conclusive due to anatomical distortion, since it permits the detection of tumoural lesions undetected by the radiological image techniques but metabolically active. The FDG-PET could be more sensitive than an increased marker value, and facing an increase of the latter it permits a non-invasive localisation of the disease.

Synthesis and reactivity of bridging and terminal hydrosulfido palladium and platinum complexes. Crystal structures of [NBu4]2[(Pt(c6F5)2(mu-SH)]2], [Pt(C6F5)2(PPh3)[S(H)AgPPh3]], and [Pt(C6F5)2(PPh3)[S(AuPPh3)2]]

The reactions of the hydroxo complexes [M(2)R(4)(mu-OH)(2)](2)(-) (M = Pd, R = C(6)F(5), C(6)Cl(5); M = Pt, R = C(6)F(5)), [[PdR(PPh(3))(mu-OH)](2)] (R = C(6)F(5), C(6)Cl(5)), and [[Pt(C(6)F(5))(2)](2)(mu-OH)(mu-pz)](2-) (pz = pyrazolate) with H(2)S yield the corresponding hydrosulfido complexes [M(2)(C(6)F(5))(4)(mu-SH)(2)](2-), [[PdR(PPh(3))(mu-SH)](2)], and [[Pt(C(6)F(5))(2)](2)(mu-SH)(mu-pz)](2-), respectively. The monomeric hydrosulfido complexes [M(C(6)F(5))(2)(SH)(PPh(3))](-) (M = Pd, Pt) have been prepared by reactions of the corresponding binuclear hydrosulfido complexes [M(2)(C(6)F(5))(4)(mu-SH)(2)](2-) with PPh(3) in the molar ratio 1:2, and they can be used as metalloligands toward Ag(PPh(3))(+) to form the heterodinuclear complex [(C(6)F(5))(2)(PPh(3))[S(H)AgPPh(3)]], and toward Au(PPh(3))(+) yielding the heterotrinuclear complexes [M(C(6)F(5))(2)(PPh(3))[S(AuPPh(3))(2)]]. The crystal structures of [NBu(4)](2)[[Pt(C(6)F(5))(2)(mu-SH)](2)], [Pt(C(6)F(5))(2)(PPh(3))[S(H)AgPPh(3)]], and [Pt(C(6)F(5))(2)(PPh(3))[S(AuPPh(3))(2)]] have been established by X-ray diffraction and show no short metal-metal interactions between the metallic centers.

[Non classical subtypes of diabetes mellitus]

BACKGROUND

Some adult, obese and diabetic patients, initiate their disease with a severe diabetic ketoacidosis without a precipitating factor and do not require insulin thereafter. These patients are classified as having a "non classical" diabetes mellitus.

AIM

To study the clinical, immunological, genetic and metabolic features of patients with non classical diabetes mellitus.

PATIENTS AND METHODS

Ten patients (9 men, aged 45 +/- 12 years old) with non classical diabetes mellitus were studied. Anti islet and anti glutamic acid decarboxylase antibodies (ICA and anti GAD), HLA DQ alpha arginine 52 and non aspartic beta 57 were measured. Insulin secretion was measured by C peptide after glucagon injection and with the minimal model of Bergman. The latter model was also used to determine insulin sensitivity.

RESULTS

Three patients were immunologically classified as type 1, since they had positive ICA or antiGAD antibodies and type 1 genetics (neutral or susceptible HLA DQ alpha and beta). They had insulin secretion after glucagon stimulus (C peptide ranging from 2.2 to 7.5 pmol/ml), but an almost absent response to a glucose load. They were also insulin resistant (a sensitivity index ranging from 0.05 to 1.67 x 10(-4) min/microU x ml). These three cases could be categorized as latent type 1. The other seven patients were ICA negative and antiGAD negative. Five had a susceptible HLA genotype for type 1 diabetes and two were neutral. All had insulin secretion after glucagon stimulation and a variable response to glucose. Six were insulin resistant (sensitivity index ranging from 0.32 to 1.29 x 10(-4) min/microU x ml). One patient was insulin sensitive (sensitivity index of 3.83 x 10(-4) min/microU x ml). Therefore all these patients were classified as type two diabetics with an atypical debut.

CONCLUSIONS

Not all diabetics presenting with a severe diabetic ketoacidosis are type I. Among these, there are subjects with a latent type 1 diabetes or with an atypical type 2 diabetes.

Dietary fats affect rat plasma lipoprotein secondary structure as assessed by Fourier transform infrared spectroscopy

This investigation was undertaken to determine by Fourier transform infrared spectroscopy the effects of diets enriched with fish, sunflower or olive oils on the secondary structure of plasma HDL and LDL from rats, as well as the effects on lipid unsaturation and acyl chain lengths. Controls were fed a commercial diet. In HDL, random coil conformation was relatively high in rats fed the fish diet, probably due to the irregular geometry of polyunsaturated fatty acids interacting with apoproteins. Parallel structural behaviors were observed for rats fed control and olive oil diets. The lowest lipid unsaturation level was found in HDL of rats fed olive oil, and acyl chain lengths were slightly increased by the three fats. Rats fed olive oil had the lowest percentage of LDL beta-sheets and these were more abundant in rats fed the fish oil diet. The least lipid unsaturation in LDL was in rats fed the olive oil diet. No significant differences in acyl chain lengths were observed. Certain protein conformational changes and/or apoprotein composition differences due to dietary fat may affect the binding between lipoproteins and their receptors in cells.

[An automatic system for anatomophysiological correlation in three planes simultaneously during functional neurosurgery]

INTRODUCTION

The Neurosurgical Deep Recording System (NDRS) using a personal computer takes the place of complex electronic equipment for recording and processing deep cerebral electrical activity, as a guide in stereotaxic functional neurosurgery. It also permits increased possibilities of presenting information in direct graphic form with automatic management and sufficient flexibility to implement different analyses.

OBJECTIVE

This paper describes the possibilities of automatic simultaneous graphic representation in three almost orthogonal planes, available with the new 5.1 version of NDRS so as to facilitate the analysis of anatomophysiological correlation in the localization of deep structures of the brain during minimal access surgery.

MATERIAL AND METHODS

This new version can automatically show the spatial behaviour of signals registered throughout the path of the electrode inside the brain, superimposed simultaneously on sagittal, coronal and axial sections of an anatomical atlas of the brain, after adjusting the scale automatically according to the dimensions of the brain of each individual patient. This may also be shown in a tridimensional representation of the different planes themselves intercepting.

RESULTS

The NDRS system has been successfully used in Spain and Cuba in over 300 functional neurosurgery operations. The new version further facilitates analysis of spatial anatomophysiological correlation for the localization of brain structures.

CONCLUSION

This system has contributed to increase the precision and safety in selecting surgical targets in the control of Parkinson s disease and other disorders of movement.

Persistent hypercalcitoninemia in patients with medullary thyroid cancer: a therapeutic approach based on selective venous sampling for calcitonin

BACKGROUND

Persistent or recurrent medullary thyroid carcinoma (MTC) can be cured by microdissection of residual metastatic lymph nodes in the neck. Selective venous sampling can be used for localization. The aim of this study is to prospectively analyze our results with a therapeutic approach based on venous sampling, in patients with hyperthyrocalcitoninemia after thyroidectomy for MTC.

METHODS

Selective venous sampling for determination of stimulated calcitonin was obtained in all patients after performing a complete laboratory and imaging workup. Patients with a gradient between the suprahepatic vein and the superior vena cava underwent unilateral or bilateral extensive lymph node dissection. We used the gradient between the right and left jugular veins to decide which side of the neck to operate. Calcitonin levels were obtained after surgery and a pentagastrin test was performed one year later if basal levels remained normal.

RESULTS

Mean age of the five women with a neck gradient in the selective venous sampling who underwent neck exploration was 45 years. In all patients metastatic lymph nodes were found at the site suggested by the study. Mean positive/resected lymph nodes were 5/20. Postoperative basal and stimulated levels of calcitonin became normal in two patients at one year of follow up.

CONCLUSION

Selective venous sampling is useful to localize recurrent MTC.

Long-term efficiency of catalytic converters operating in Mexico City

A 1999 ordinance by the Government of Mexico City bans 1993 model-year vehicles from on-road operation if their catalytic converters are not replaced with new ones. To validate the benefits of this action, we examined three issues related to exhaust emissions of vehicles equipped with catalytic converters. After selecting representative fleets of in-use vehicles, a comparison between emissions and catalyst efficiency in cars with two categories of exhaust emission limits was carried out. For that purpose, two fleets were selected, each made up of 10 vehicles run under similar conditions. A third, larger fleet with emissions control systems was used to evaluate and simulate real-world conditions of vehicles in a controlled laboratory. Finally, the aging effect on the catalytic converter was studied on vehicles run for 100,000 km, replacing their old emission control devices for new ones. The 1991-1992 model-year vehicles showed a high percentage of compliance with the corresponding emissions standard (90%) in comparison with 1993 model-year and later vehicles (Tier 0). However, NOx emissions were higher for the newer vehicles. Fifty percent of the 1991-1992 model-year vehicles evaluated under the official inspection/maintenance (I/M) procedure did not meet the regulated emissions standard when the results were compared with those of the U.S. Federal Test Procedure FTP-75. Our results suggest that the replacement of old catalytic converters with new ones will have little effect on decreasing polluting emissions because these vehicles were in very bad mechanical condition. Results of catalytic activity as a function of mileage indicated inefficient catalyst performance for the fleets tested. All pollutant conversions were below 90% efficiency, and they deteriorated by an average of 30% after the vehicles were run for 100,000 km.

Localization and expression of BCAT during pregnancy and lactation in the rat mammary gland

During lactation, branched-chain aminotransferase (BCAT) gene expression increases in the mammary gland. To determine the cell type and whether this induction is present only during lactation, female rats were randomly assigned to one of three experimental groups: pregnancy, lactation, or postweaning. Mammary gland BCAT activity during the first days of pregnancy was similar to that of virgin rats, increasing significantly from day 16 to the last day of pregnancy. Maximal BCAT activity occurred on day 12 of lactation. During postweaning, BCAT activity decreased rapidly to values close to those observed in virgin rats. Analyses by Western and Northern blot revealed that changes in enzyme activity were accompanied by parallel changes in the amount of enzyme and its mRNA. Immunohistochemical studies of the mammary gland showed a progressive increase in mitochondrial BCAT (mBCAT)-specific staining of the epithelial acinar cells during lactation, reaching high levels by day 12. Immunoreactivity decreased rapidly after weaning. There was a significant correlation between total BCAT activity and milk production. These results indicate that the pattern of mBCAT gene expression follows lactogenesis stages I and II and is restricted to the milk-producing epithelial acinar cells. Furthermore, BCAT activity is associated with milk production in the mammary gland during lactation.

Marchantin M trimethyl ether

The title macrocycle, C(31)H(30)O(5), is comprised of two bibenzyl ether moieties linked cyclically by spacers which each consist of two-carbon alkyl chains. The observed conformation of the macrocycle may be partly stabilized by intramolecular C-H.O close contacts. The packing appears to be directed by van der Waals forces. This work explains the occurrence of a signal found in the (1)H NMR spectra of both marchantinquinone and marchantin M trimethyl ether at delta = 5. 49 and 5.56 p.p.m., respectively. The shift in the position of the expected peak can be explained by the proximity of an H atom belonging to one of the aromatic rings to another ring in the same molecule.