Nitrogen and phosphorus budget in an intensive irrigation area and effects on littoral water and groundwater (Yaqui Valley, Northwestern Mexico).

The Yaqui River Irrigation District is a region in Mexico with intensive agricultural production; thus, large quantities of fertilizers are used, and excess fertilizer can affect the quality of water bodies. The aim of this work was to estimate the water budget and nitrogen (N) and phosphorous (P) mass budgets to evaluate possible contamination of a littoral water body (Tóbari Bay) and leachates into an aquifer (Yaqui Valley aquifer). Wheat and corn crops were studied, climate information was compiled, and soil and water samples were collected for analysis. The water budget showed excess irrigation occurred due to the need for soil washing to prevent salinization. A total of 24% of all irrigation water was used for crops, 60% was discharged into the bay through runoff of the drainage system, and 16% corresponded to effective infiltration (aquifer recharge). The N budget showed that of the 100% N input, the highest percentage was used by plants (63%), and only minimal loss occurred through runoff (11%) and leachate into the aquifer (7%). The remaining N stayed in the soil (18%) or was volatilized (1%). These results indicate that the drainage system prevented large amounts of N from entering the aquifer; thus, the N concentrations in the groundwater did not exceed the regulated maximum limit for drinking water (10 mg N-NO3/L). In terms of the water pollution level in the bay, the presence of NO3- was minimal (concentrations below the quasintifiable limit). Of the 100% of P that was applied, 55% was used by the plants, and 40% remained in the soil; therefore, the P that was transported by runoff or was leached was minimal (3 and 2%, respectively). However, this minimal amount of P ranged from 0.1 to 0.2 mg/L in the bay, and these values exceeded the suggested values for the protection of aquatic life (0.01 mg/L). The administrators of the irrigation district must pay special attention to phosphate fertilizer management and implement irrigation techniques that increase water use efficiency.

Fractal signatures of the COVID-19 spread.

Recent quantitative approaches for studying several aspects of urban life and infrastructure have shown that scale properties allow the understanding of many features of urban infrastructure and of human activity in cities. In this paper, we show that COVID-19 virus contamination follows a similar pattern in different regions of the world. The superlinear power-law behavior for the number of contamination cases as a function of the city population, with exponent ß of the order of 1.15 is always obtained. Due to the strong indication that scaling is a determinant feature of covid-19 spread, we propose an epidemiological model that embodies a fractal structure, allowing a more detailed description of the observed data about the virus spread in different countries and regions. The hypothesis that fractal structures can be formed in cities as well as in larger networks is tested, indicating that indeed self-similarity may be found in networks connecting several cities.

Bisphosphonate-related osteonecrosis. Application of adipose-derived stem cells in an experimental murine model.

BACKGROUND: Bisphosphonate-related osteonecrosis of the jaw is a pathological condition without effective established treatment and preventive strategies. The aim of this study was to analyse the effect of adipose-derived stem cells (ASC) in an experimental murine model of osteonecrosis. MATERIAL AND METHODS: 38 Wistar rats were injected intraperitoneally with zoledronic acid. After treatment, upper jaw molars were extracted. The animals were randomly assigned to one of two groups. In the control group, saline solution was applied over the alveolar sockets after the tooth extractions. In the treatment group, ASCs were applied instead of saline solution. The control and treatment groups were subdivided based on the time of euthanasia. A clinical and histological analysis was performed. RESULTS: The presence of osteonecrosis in alveolar bone was observed in a similar distribution in both groups. In the ASC-treated group, new bone formation was greater than in controls. CONCLUSION: In this study, application of ASCs showed greater new bone formation in an osteonecrosis-like murine model. Previous inhibited post-extraction bone remodelling could be reactivated, and these findings appeared to be secondary to implantation of ASCs.

Result of the implementation of telematic consultations in orthopaedic surgery and traumatology during COVID-19 laparoscopic surgery. / Resultado de la implantación de consultas telemáticas en cirugía ortopédica y traumatología durante la pandemia COVID-19.

The COVID pandemic has made telematic consultations a basic tool in daily practice. AIMS: The main objective of the study is to assess the results of the application of telematic consultations to limit the mobility of patients. The operational objectives are; to propose a consultation plan, to know how attendance limits consultations and to define which pathologies benefit the most from this plan. METHODS: A scheme is proposed with the creation of pre-scheduled clinic to assess suitability and the possibility of carrying them out in a single non face-to-face act. RESULTS: Phone call to 5,619 patients were made with a lack of response of 19%. The cases of 74% of the patients that answered were resolved virtually. There is a difference between units, obtaining a higher answering rate from patients appointed to specific clinic units, OR = 0.60, or to general trauma ones, OR = 0.67. The lowest answering rate was obtained from those derived from the emergency department. Twenty per cent of the consultations were not accompanied by complementary tests that would have favored the resolution in a single act. The general trauma consultations, OR = 0.34, postoperative control, OR = 0.49, and specific unit ones, OR = 0.40, were the ones that better met this requirement. Out of the remaining patients, the general trauma consultations, OR = 0.50, and those referred to units, OR = 0.54, were the ones that had a higher resolution rate without in- person consultation. CONCLUSIONS: The cases of 74% of the patients who answered the phone call were resolved virtually. Cases of 20% of the patients cannot be solved in a single act because they are derived without complementary tests. Osteosynthesis and postoperative arthroscopic follow-up consultations are the ones that need to be carried out in person the most.

Poly-beta-hydroxyalkanoate exert a protective effect against carbon starvation and frozen conditions in Sphingopyxis chilensis.

Several bacterial species have developed physiological response to avoid the cellular damage when are exposed to carbon starvation or frozen stress. For example survival to inanition has been related to endogenous substrates consumptions. The aim of this study was to evaluate if poly-beta-hydroxylkanoates (PHA) consumption enable Sphingopyxis chilensis S37 to survive under carbon starvation or frozen condition. Bacterial cells were grown in R(2)A broth for 48 h, and suspended in mineral saline solutions, without carbon source. The cellular suspension was incubated for 48 or 120 h at 30 degrees C, followed by a frozen period of 48 h at -20 degrees C, and viable bacterial cells were evaluated by the microdrop method. The proportions of cells with PHA were also determined by flow cytometry using Nile Red dye. The results indicate that S. chilensis were able to survive under carbon starvation and frozen conditions. Simultaneously, a decrease in the number of cells containing PHA, and a decrease in the biovolume of the cells (c.a 2.5 times) were also observed under these conditions. The results suggest that consumptions of PHA contributed to the surviving of S. chilensis under frozen stress.

[Sagittal sinus thrombosis as a rare cause of postpartum headache: a case report]. / Trombosis del seno sagital cerebral: causa infrecuente de cefalea del postparto: a propósito de un caso.

Postpartum cerebral vein thrombosis is a very rare entity (3-4 cases per million). Clinical manifestations vary, though persistent headache is almost always reported, meaning that differential diagnosis should be performed to rule out other causes of postpartum headache. Recognized risk factors for this disease are the prothrombotic state of pregnancy (third trimester), excess weight, and thrombophilia Accidental dural puncture, protein C and S deficiencies, factor V Leiden mutation, antiphospholipid syndrome, and the use of oral contraceptives have also been implicated. The diagnostic test of choice is magnetic resonance imaging, as it is convenient and harmless, though transcranial Doppler ultrasound can also be used. Pulmonary angiography is the gold-standard test. The treatment of choice is anticoagulant therapy with heparin (a treatment that is controversial, however, due to the high risk of rebleeding), followed by long-term treatment with antivitamin K drugs. We report a case of thrombosis of the upper longitudinal sinus associated with persistent postpartum headache and a history of a failed attempt at epidural puncture for analgesia during labor. The case posed interesting diagnostic questions.

Immunopathological evaluation of recombinant mycobacterial antigen Hsp65 expressed in Lactococcus lactis as a novel vaccine candidate.

Bovine tuberculosis (TBB) is a zoonotic disease distributed worldwide and is of great importance for public health and the livestock industry. Several experimental vaccines against this disease have been evaluated in recent years, yielding varying results. An example is the Bacillus Calmette-Guérin (BCG) vaccine, which has been used extensively in humans and tested in cattle showing mixed results related to protection (0-80%) against Mycobacterium bovis. In this study, we used the food-grade bacterium Lactococcus lactis as an expression system for production of mycobacterial protein Hsp65. For this purpose, the construction of a replicable plasmid in strain NZ9000 L. lactis (pVElepr) was conducted, which expressed the Mycobacterium leprae Hsp65 antigen, and was recognized by traded anti-Hsp65 antibodies. The strain NZ9000-pVElepr was applied to calves that were negative to tuberculin test and the immune response was monitored. The results showed that immune response was not significantly increased in calves with NZ9000-pVElepr with respect to control groups, and no injury was observed in any lung or lymph of the calves. Finally, this study suggest that the recombinant NZ9000 strain of L. lactis may protect against the development of M. bovis infection, although studies with longer exposure to this pathogen are necessary to conclude the matter.

Surgical Gown's Cuff Modification to Prevent Surgical Contamination.

The gown-glove interface is the weakest point in the barrier system of gown and glove protection for the surgeon. We are herein presenting an easy modification in the cuff of the gown that increases the security of the gown-glove interface.

Polyetheretherketone custom-made implants for craniofacial defects: Report of 14 cases and review of the literature.

BACKGROUND: Craniofacial defects tend to carry functional and esthetic consequences for the patient. The complex shapes in this region make such reconstructions a challenging procedure and the most suitable material to be used remains controversial. METHODS: We report a series of 14 patients whose craniofacial defects were reconstructed using a computer designed PEEK-PSI (Polyetheretherketone- Patient Specific Implant). We analyzed the complications and outcomes of PEEK custom-made implants and compared our results with those of other case series reported in the current literature. RESULTS: Fourteen patients underwent craniofacial reconstruction using a PEEK-PSI. Three cases involved a one-step primary reconstruction and the rest of cases underwent a delayed reconstruction. Two cases (14.3 %) presented infection and only in one case was the implant definitively removed. Esthetic results were considered to be highly satisfactory. CONCLUSION: With CAD-CAM techniques, it is possible to prefabricate an individual implant. The ideal material for reconstructing maxillofacial defects does not exist, but PEEK has demonstrated good outcomes. When autologous bone is not available or, in selected cases with large or complex defects in the maxillofacial area, PEEK is one of the best options to reconstruct these defects. However, further studies are needed to determine the long-term results.

Intracerebroventricular injection of naloxone blocks melatonin-dependent brain [3H]flunitrazepam binding.

The pineal hormone melatonin modulates the brain benzodiazepine binding sites and its circadian rhythm. In the present study the effects of intracerebroventricular (i.c.v.) administration of naloxone (10-20 ng), alone or in association with melatonin and/or beta-endorphin, on [3H]flunitrazepam ([3H]FNZ) binding to the rat cerebral cortex of hypophysectomized rats was investigated. Melatonin (10-20 ng), beta-endorphin (10-20 ng), and melatonin + beta-endorphin (10-20 ng of each compound) all increased [3H]FNZ binding to a similar extent and in a dose-related manner. The effects of melatonin (10 ng) on [3H]FNZ binding were prevented by simultaneous injection with the specific opioid antagonist naloxone. Naloxone also blocks, although to a lesser extent, the effects of beta-endorphin and of melatonin + beta-endorphin injections. Moreover, naloxone blocks the hypophysectomy-dependent increase in [3H]FNZ binding. These results implicate the modulation of melatonin-dependent changes on brain benzodiazepine receptors by opioid peptides.

Suppressive effect of simultaneous injection of ACTH1-10 and beta-endorphin on brain [3H]flunitrazepam binding.

Seven-day hypophysectomized rats were intracerebroventricularly (i.c.v.) injected with beta-endorphin, ACTH1-10 or beta-endorphin+ACTH1-10 (10-20 ng of each compound) and the [3H]flunitrazepam ([3H])FNZ) binding to the rat cerebral cortex of hypophysectomized rats was assayed one hour later. The i.c.v. injection of ACTH1-10 (10-20 ng) or beta-endorphin (10-20 ng) significantly increased [3H]FNZ binding to a similar extent. The effect of i.c.v. injection of ACTH1-10 on brain binding was blunted by simultaneous beta-endorphin administration at the same doses. The i.c.v. naloxone injection (10-20 ng) did not modify the effect of ACTH1-10 (10 ng) on [3H]FNZ binding, but counteracted, in a dose-related manner, the blocking effect of beta-endorphin on ACTH1-10-dependent brain [3H]FNZ binding. The results suggest the existence of an opioid-melanopeptide integration to control brain benzodiazepine receptors.

Characterization of ouabain high-affinity binding to rat cerebral cortex. Modulation by melatonin.

High-affinity [3H]ouabain binding to membrane preparations of rat cerebral cortex was examined using a rapid filtration procedure. At 37 degrees C, binding reached equilibrium in about 60 min. Scatchard analyses of the data at equilibrium revealed a single population of binding sites with a dissociation constant of KD = 3.1 +/- 0.36 nM and a binding site concentration of Bmax = 246.4 +/- 18.4 fmol/mg protein. Kinetic analyses of the association and dissociation curves indicated a kinetic KD = 4.6 nM, which is in good agreement with the value obtained at equilibrium. When various digitalis compounds were tested for their ability to inhibit [3H]ouabain binding, the following Ki values (nM) were obtained: ouabain (3.9); digoxin (18); acetyl-digitoxin (66); k-strophanthin (95); digitoxin (236). When melatonin was added to the incubation medium, the ability of ouabain to inhibit [3H]ouabain binding increased in a dose-related manner to yield the following Ki values (nM): melatonin 10 nM (2); melatonin 20 nM (1.2); melatonin 40 nM (0.8). These data suggest the existence in the rat cerebral cortex of high-affinity ouabain binding sites which may be a locus for the molecular action of melatonin.

HTLV-I positive progressive spastic paraparesis (TSP) associated with a lymphoid disorder in three Chilean patients.

We describe the clinical and laboratory features in three Caucasian Chilean patients with tropical spastic paraparesis (TSP) associated with/or preceded by a lymphoproliferative disorder involving cutaneous lesions and localised lymphadenopathy. The neurological symptoms and signs were characteristic of TSP and CSF examination revealed the presence of oligoclonal bands. All three patients had a moderate leucocytosis (10-14 x 10(9)/l) with eosinophilia and a minority (2-4%) of circulating atypical polylobed or ATLL-like lymphocytes. Lymph node histology showed a diffuse pattern of infiltration (1 case) and marked expansion of the paracortical zone with convoluted lymphocytes and immunoblasts (2 cases). Skin biopsy demonstrated a dermal lymphoid infiltration with epidermotropism. Antibodies to HTLV-I were detected in the serum and CSF in the three patients and Southern blot analysis of peripheral blood mononuclear cells showed a monoclonal integration of HTLV-I proviral DNA in one case whereas in the two others the pattern was indicative of low level polyclonal integration. All three patients were treated with prednisolone and one with PUVA with transient partial response on the skin and neurological manifestations. Two patients died months to 5 years from presentation and the other is alive 12 years from diagnosis with active neurological and skin disease. The simultaneous occurrence of HTLV-I associated TSP with smouldering ATLL and a cutaneous ATLL or pre-leukaemic form is discussed.

Melatonin counteracts pinealectomy-dependent decreases in rat brain [3H]flunitrazepam binding through an opioid mechanism.

The effect of intracerebroventricular (i.c.v.) injection of melatonin and/or beta-endorphin on the [3H]flunitrazepam binding sites in the cerebral cortex of pinealectomized or superior cervical ganglionectomized rats was studied. Pinealectomy decreased the maximum concentration of benzodiazepine receptors (Bmax) without affecting the dissociation constant (KD), while melatonin, ineffective in control animals, counteracted the effect of pinealectomy. Intracerebroventricular injection of beta-endorphin increases Bmax in both control and pinealectomized animals, the effect being significantly higher in the latter. Simultaneous i.c.v. injection of melatonin + beta-endorphin did not further increase Bmax in any group, whereas i.c.v. injection of naloxone significantly blocked the effects of melatonin and/or beta-endorphin administration. Pineal sympathetic denervation produced a significant increase in Bmax and KD, whereas i.c.v. injection of melatonin further increased the former, restoring KD to control values. Neither i.c.v. administration of beta-endorphin or melatonin + beta-endorphin significantly modified the ganglionectomy-dependent increase in Bmax, although both treatments restored KD to control values. Naloxone administration had no effect on beta-endorphin- and melatonin + beta-endorphin-treated ganglionectomized groups, but counteracted the increased effect of melatonin on Bmax in ganglionectomized animals.

Pinealectomy increases ouabain high-affinity binding sites and dissociation constant in rat cerebral cortex.

The effect of the pineal gland on the ouabain high-affinity binding sites (Kd = 3.1 +/- 0.4 nM, Bmax = 246.4 +/- 18.4 fmol/mg protein) in rat cerebral cortex was studied. Pinealectomy increased Bmax (940.7 +/- 42.8 fmol/mg protein) and Kd (7.6 +/- 1.5 nM) while melatonin injection (100 micrograms/kg b.wt.) counteracted these effects, restoring kinetic parameters (Kd = 1.9 +/- 0.05 nM; Bmax = 262.2 +/- 29.6 fmol/mg prot) to control values. Melatonin activity on ouabain binding in vitro did not depend upon a direct effect on the binding sites themselves. However, in competition experiments, melatonin increased binding affinity of ouabain as shown by the decreased IC50 values.

Spirulina maxima prevents fatty liver formation in CD-1 male and female mice with experimental diabetes.

The dietary administration of 5% Spirulina maxima (SM) during four weeks to diabetic mice, starting one week after a single dose of alloxan, 250 mg/Kg body weight, prevented fatty liver production in male and female animals. The main action of SM was on triacylglycerol levels in serum and liver. There was also a moderate hypoglycemia in male mice. The thiobarbituric acid reactive substances also decreased in serum and liver after SM administration. There was also a decrease in the percentage of HDL in diabetic mice that was reverted by the SM administration. The sum of LDL + VLDL percentages was also partially normalized in diabetic animals by the SM administration. An additional observation was the lower incidence of adherences between the liver and the intestine loops in the diabetic mice treated with SM compared with diabetic mice without SM. Male and female mice showed differences to diabetes susceptibility and response to SM, the female being more resistant to diabetes induction by alloxan and more responsive to the beneficial effects of SM. It is worth future work of SM on humans looking for better quality of life and longer survival of diabetic patients.

Arthrospira maxima prevents the acute fatty liver induced by the administration of simvastatin, ethanol and a hypercholesterolemic diet to mice.

An evident fatty liver, corroborated morphologically and chemically, was produced in CD-1 mice after five daily doses of simvastatin 75 mg/Kg body weight, a hypercholesterolemic diet and 20 percent ethanol in the drinking water. After treating the animals, they presented serum triacylglycerols levels five times higher than the control mice, total lipids, cholesterol and triacylglycerols in the liver were 2, 2 and 1.5 times higher, respectively, than in control animals. When Arthrospira maxima was given with diet two weeks prior the onset of fatty liver induction, there was a decrement of liver total lipids (40%), liver triacylglycerols (50%) and serum triacylglycerols (50%) compared to the animals with the same treatment but without Arthrospira maxima. In addition to the mentioned protective effect, the administration of this algae, produced a significant increase (45%) in serum high density lipoproteins. The mechanism for this protective effect was not established in these experiments.

Micellar behavior of tetradecyldimethylbenzylammonium chloride in water-alcohol mixtures.

The effect of butanol and benzyl alcohol on the critical micelle concentration and the degree of ionization of micelles of tetradecyldimethylbenzylammonium chloride has been studied conductometrically in the temperature range of 5 to 40 degrees C at 5 degrees C intervals. The results indicate that some self-association process of benzyl alcohol in the aqueous phase commences when its concentration amounts to ca 0.05 m. By applying the theoretical treatment suggested by Motomura for binary surfactant systems, the molar fraction of alcohol in the micelle and the standard free energy of solubilization were estimated from the dependence of cmc on temperature and alcohol concentration. For comparative purposes the micellar properties of tetradecyltrimethylammonium bromide in water-alcohol systems at 25 degrees C have also been studied.

Somatosensory evoked potentials and dopaminergic responsiveness to apomorphine and levodopa in parkinsonian patients.

Short-latency somatosensory evoked potentials (SSEPs) were recorded from 10 parkinsonian patients in 'off' and 'on' states induced by apomorphine and levodopa. The effects of apomorphine and long-term levodopa treatment on the frontal N30 component were assessed and compared with healthy controls. Nine of 10 patients tested with apomorphine showed a significant improvement (p<0.01) in N30 frontal component amplitude whereas in six of eight patients similarly assessed with levodopa we obtained a comparable improvement in SSEPs (p<0.01). Parietal SSEPs remained unchanged. This normalization of frontal SSEPs was concomitant with the clinical response and in some patients preceded the motor response. No changes were obtained in control subjects. The improvement in N30 potential occurred regardless of disease duration or the presence of motor fluctuations. SSEPs may represent an objective approach for assessing the dopaminergic response and the fluctuations of motor disability in parkinsonian patients.

Post-coronariography dissection of the right coronary artery.

The case of a patient undergoing an emergency aortocoronary bypass to the right coronary artery after its acute dissection at coronariography is presented. Surgery was carried out two hours after the incident. After successful recovery and postoperative study, it was concluded that the main technical problem posed by this operation which was whether or not to ligate proximally the right coronary was satisfactorily solved by the initial decision not to ligate it.