Obtaining and evaluating of enzymatic extracts from hairless canary seed (CDC Maria) as gluten-free bread-improving agents.

In this study, enzyme extracts were obtained from hairless canary seeds (CDC Maria) and used as gluten-free bread improvers. The enzyme extraction was done with a specific protein buffer solution and subsequent centrifugation. The supernatant was called crude enzyme extract, a fraction of this extract was refrigerated (CE) and another fraction was lyophilized (CEL). The lyoprotective effect of corn fiber (CEL + CF), maltodextrin (CEL + M), and inulin (CEL + I) was evaluated. Each enzyme extract was added to a gluten-free bread at 0.25%, 0.5%, 0.75% and 1% (w/w). The quality of the gluten-free bread was determined by external and internal characteristically, physical and sensory analysis: analysis of the lamella thickness, the shape factor of pores, the final volume, the aeration percentage, the texture profile analysis, the pore size distribution and shelf-life time. The results showed that the formulation with CEL at 0.5% (w/w) significantly improved the gluten-free bread quality properties, generating an increase of the final volume and aeration percentage, a reduction of the firmness, chewiness and sample aging, and a finer and more uniform crumb structure when compared to a control sample (P < 0.001). This study revealed the potential of a food-improving additive obtained from a natural origin with a high-level production in Argentina.

Adaptaciones de la Enseñanza Anatómica Durante el COVID-19 en la Universidad Complutense de Madrid. Evaluación de los Estudiantes / Adaptations of Anatomical Teaching During COVID-19 at the University Complutense of Madrid. Evaluation by the Students

Las restricciones por la pandemia del COVID-19 supusieron la transición abrupta a una enseñanza online tanto del contenido teórico como práctico y de la evaluación final de las asignaturas que imparte el departamento en varias titulaciones. En previsión de que el siguiente curso académico 2020-21 se vería totalmente afectado, se desarrollaron una serie de materiales didácticos propios, como la elaboración de guiones de teoría y práctica que incorporaron imágenes de modelos anatómicos, prosecciones, anatomía radiológica y anatomía ecográfica. La percepción de esta innovación fue evaluada por los estudiantes a través de una encuesta en línea y sus respuestas mediante una escala tipo Likert. Participaron 346 estudiantes de las titulaciones de Fisioterapia (n= 66), Medicina (n= 169), Podología (n= 44) y Terapia Ocupacional (n= 67). Las puntuaciones medias más altas correspondieron a los estudiantes de Podología y Terapia Ocupacional, ambas presentaron diferencias significativas con los otros tres subgrupos de alumnos (p<.0001). El puntaje promedio más bajo correspondió a los estudiantes de Medicina de segundo año académico que presentó significancia con los otros cuatro subgrupos de estudiantes (p<.0001). Se analizaron las carencias del sistema educativo en la Universidad Complutense de Madrid reveladas por la pandemia del Covid19. Esta crisis ha puesto de manifiesto la necesidad de que los educadores médicos en general y los anatomistas en particular estén capacitados en el uso de la tecnología disponible y en la creación de sus propios materiales didácticos multimedia.

SUMMARY: Restrictions due to COVID-19 pandemic meant an abrupt transition to online teaching. This change affected teaching, practical sessions and assessments of the subjects taught by the department in various degrees. In anticipation that the following academic year 2020-21 would be totally affected, a series of didactic materials were therefor developed. These materials included the preparation of theory and practice scripts that incorporated images of anatomical models, pro-sections, radiological anatomy, and ultrasound anatomy. Perceptions by the students of these innovations were recorded through an online survey and their responses evaluated through a Likert-type scale. 346 students from Physiotherapy (n= 66), Medicine (n= 169), Podiatry (n= 44) and Occupational Therapy (n= 67) degrees participated. The highest average scores corresponded to the students of Podiatry and Occupational Therapy, both presented significant differences with the other three subgroups of students (p<.0001). The lowest average score corresponded to medical students in their second academic year, which presented significance with the other four subgroups of students (p<.0001). The shortcomings of the educational system of the Complutense University of Madrid that were highlighted by the COVID-19 pandemic were analyzed. This crisis underscored the need for medical educators in general, and anatomists in particular, to be trained in the use of available technology and to produce their own multimedia teaching materials.

Brain and spinal cord lesion criteria distinguishes AQP4-positive neuromyelitis optica and MOG-positive disease from multiple sclerosis.

OBJECTIVE: Test the ability of a brain and spinal cord MRI criteria to differentiate neuromyelitis optica spectrum disorders and MOG-disease from MS. MRI criteria was further tested in patients with CIS and pediatric MS. BACKGROUND: MOG-disease and neuromyelitis optica spectrum disorders can present clinical and radiological features strikingly similar to those of MS. Previously, diagnostic criteria based on brain MRI have been proposed to distinguish between these demyelinating diseases (Matthews-Jurynczik criteria), but spinal cord imaging and its relevance in CIS have not been evaluated. Simple brain and spinal cord MRI criteria may help separate these three inflammatory CNS diseases both in adults and children, aiding in early diagnostic decision-making, such as need for antibody testing. DESIGN/METHODS: We included 150 participants (23 with aquaporin-4-positive neuromyelitis optica spectrum disorder, 14 with MOG-disease, 20 with aquaporin-4-negative neuromyelitis optica spectrum disorder, 48 with adult-onset relapsing remitting MS, 24 with pediatric-onset MS and 21 with clinically isolated syndrome). Brain and spinal cord MRI scans were anonymised and scored by 2 separate raters, based on two sets of criteria: one previously described by Matthews and colleagues (including presence of at least one lesion adjacent to the body of lateral ventricle and in the inferior temporal lobe, or presence of subcortical U-fiber lesion or a Dawson's finger-type lesion), and an extended version including spinal cord features (non-longitudinally extensive cervical lesion). RESULTS: Extended MRI brain and spinal cord lesion criteria were able to separate adult-onset relapsing remitting MS with 100% sensitivity and 87% specificity from aquaporin-4-positive neuromyelitis optica spectrum disorder; and with 100% sensitivity and 79% specificity from MOG-disease. Additionally, brain and spinal cord criteria showed 100% sensitivity and specificity in patients presenting optic neuritis. Brain and spinal cord criteria were less sensitive in patients with CIS and in pediatric MS patients. CONCLUSIONS: Our data suggest radiological criteria can be useful to separate MS from MOG- and aquaporin-4-positive neuromyelitis optica spectrum disorders, in particular in patients with optic neuritis. Further work is needed to support their use in CIS.

Resultados clínicos y radiológicos de las fracturas de húmero proximal tratadas mediante enclavado intramedular, así como posibles factores de riesgo de un mal resultado / Clinical and radiological results of fractures of the proximal humerus treated with intramedullary nailing and possible risk factors of a poor outcome

Antecedentes: Evaluar los resultados clínicos y radiográficos de las fracturas de húmero proximal tratadas mediante fijación con clavo intramedular, así como los factores de riesgo asociados a un mal resultado. Métodos: Se han revisado retrospectivamente a pacientes con un seguimiento mínimo de un año. Se realizó una revisión clínica objetiva mediante la escala de Constant y subjetiva del grado de satisfacción, EVA y valoración de discapacidad mediante la escala de DASH. Radiológicamente, los enfermos fueron revisados mediante radiografías AP y axial en el plano escapular. Resultados: Se incluyeron 46 pacientes, 91.3% se presentó clínicamente satisfechos con el tratamiento. La movilidad media fue de 155º de flexión, 60º de rotación lateral y rotación medial. La puntuación media del Constant fue de 70 y del DASH de 15 puntos. Se encontraron diferencias significativas en cuanto al Constant en menores de 60 años, no siendo éstas significativas con el tipo de fractura o teniendo en cuenta el DASH. Radiográficamente, la tasa de consolidación fue de 95.7%, apreciándose dos casos de seudoartrosis. En 17 pacientes se observó una consolidación en varo (38.6%). Se encontraron diferencias funcionales comparando los pacientes con consolidación en varo y consolidación anatómica. Discusión: La fijación mediante clavo intramedular es un tratamiento efectivo para las fracturas de húmero proximal, sobre todo para fracturas en dos partes del cuello quirúrgico. La alta tasa de colapso en varo, sobre todo en fracturas con gran conminución, puede acarrear una disminución en la movilidad.

Background: To assess the clinical and radiological results of fractures of the proximal humerus treated with intramedullary nail fixation as well as the risk factors associated with a poor outcome. Methods: Patients were analyzed retrospectively with a minimum follow-up of one year. An objective clinical assessment was made using the Constant scale, the subjective satisfaction scale, VAS, and the DASH scale to measure disability. The radiological assessment included AP and axial X-rays in the scapular plane. Results: Forty-six patients were enrolled. The clinical assessment showed that 91.3% of them were satisfied with treatment. Mean mobility was 155º of flexion, 60º of lateral and medial rotation. The mean Constant score was 70 and the DASH score was 15. Significant differences were found in the Constant score in individuals under 60 years of age, but they were not significant considering the type of fracture or the DASH score. X-rays showed a healing rate of 95.7%, with two cases of pseudarthrosis. Varus healing was observed in 17 patients (38.6%). Functional differences were found when patients with varus healing were compared with those who had anatomical healing. Discussion: Fixation with intramedullary nailing is an effective treatment for fractures of the proximal humerus, particularly for two-segment fractures of the surgical neck. The high rate of varus collapse, particularly in very comminuted fractures, may lead to decreased mobility.

[Clinical and radiological results of fractures of the proximal humerus treated with intramedullary nailing and possible risk factors of a poor outcome]. / Resultados clínicos y radiolígicos de las fracturas de húmero proximal tratadas mediante enclavado intramedular, así como posibles factores de riesgo de un mal resultado.

BACKGROUND: To assess the clinical and radiological results of fractures of the proximal humerus treated with intramedullary nail fixation as well as the risk factors associated with a poor outcome. METHODS: Patients were analyzed retrospectively with a minimum follow-up of one year. An objective clinical assessment was made using the Constant scale, the subjective satisfaction scale, VAS, and the DASH scale to measure disability. The radiological assessment included AP and axial X-rays in the scapular plane. RESULTS: Forty-six patients were enrolled. The clinical assessment showed that 91.3% of them were satisfied with treatment. Mean mobility was 1550 of flexion, 600 of lateral and medial rotation. The mean Constant score was 70 and the DASH score was 15. Significant differences were found in the Constant score in individuals under 60 years of age, but they were not significant considering the type of fracture or the DASH score. X-rays showed a healing rate of 95.7%, with two cases of pseudarthrosis. Varus healing was observed in 17 patients (38.6%). Functional differences were found when patients with varus healing were compared with those who had anatomical healing. DISCUSSION: Fixation with intramedullary nailing is an effective treatment for fractures of the proximal humerus, particularly for two-segment fractures of the surgical neck. The high rate of varus collapse, particularly in very comminuted fractures, may lead to decreased mobility.

Methicillin-resistant Staphylococcus aureus of lineage ST398 as cause of mastitis in cows.

UNLABELLED: The objective of this study was to analyse the prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) in milk of cows with mastitis. The California mastitis test (CMT) was used to detect the presence of mastitis in all 100 cows of a farm in Brazil. The CMT was positive in milk of 115 mammary quarters from 36 cows (36%). MRSA isolates were recovered from 4 of these 36 cows with mastitis (11%), and they were further characterized (one MRSA/sample). The four MRSA isolates were typed as t011-ST398-agr1-SCCmecV and presented two different pulsed-field-gel-electrophoresis-ApaI patterns. These four MRSA isolates showed resistance to tetracycline, streptomycin and ciprofloxacin, carried the mecA, blaZ, tet(K), and tet(M) resistance genes, and presented the S84L and S80F amino acid substitutions in GyrA and GrlA proteins, respectively. Two ST398 isolates exhibited resistance to gentamicin and tobramycin [with aac(6)-aph(2") and ant(4)-Ia genes] and one isolate resistance to clindamycin [with lnu(B) and lsa(E) genes]; this latter isolate also carried the spectinomycin/streptomycin resistance genes spw and aadE. MRSA of lineage ST398 is worldwide spread, normally multidrug resistant and may be responsible for bovine mastitis. To our knowledge, this is the first detection of MRSA-ST398 in Brazil. SIGNIFICANCE AND IMPACT OF THE STUDY: Few studies on the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) from bovine isolates have been performed in Brazil. MRSA of lineage ST398 is worldwide spread and associated with farm animals. Multidrug-resistant MRSA-ST398 isolates were recovered in 11% of mastitic cows from a single farm, with one isolate carrying the unusual lsa(E), spw and aadE genes. To our knowledge, this is the first detection of MRSA-ST398 isolates in milk samples of cows with mastitis in Brazil.

Molecular characterization and clonal diversity of methicillin-susceptible Staphylococcus aureus in milk of cows with mastitis in Brazil.

Mastitis is an important disease for the dairy industry worldwide, causing economic losses and reducing milk quality and production. Staphylococcus aureus is a worldwide agent of this intramammary infection, which also causes foodborne diseases. The objective of this study was to determine the frequency of methicillin-susceptible Staphylococcus aureus (MSSA) isolates in milk of mastitis cows in Brazil and to analyze the genetic lineages and the content of antimicrobial resistance genes and virulence factors among these isolates. Fifty-six MSSA isolates were recovered from 1,484 milk samples (positive for the California mastitis test) of 518 cows from 11 different farms in Brazil (representing 51% of total Staph. aureus obtained), and they were further characterized. Methicillin-susceptible Staphylococcus aureus were isolated from 3.7% of California mastitis test-positive tested milk samples and from 6.2% of tested mastitic cows. Methicillin-susceptible Staphylococcus aureus isolates were characterized by spa typing, agr typing, and multilocus sequence typing, and resistance and virulence traits were investigated by PCR. Seven spa types were identified among MSSA (% of isolates): t127 (44.6), t605 (37.5), t002, t1784, t2066 (1.8), and 2 new ones: t10856 (10.7) and t10852 (1.8). Five distinct sequence types (ST) were detected (% of isolates): ST1 (46.4), ST126 (37.5), ST133 (10.7), ST5 (3.6), and a novel ST registered as ST2493 (1.8). Resistances were detected for streptomycin, chloramphenicol, and tetracycline. One strain contained the chloramphenicol resistance gene (fexA; included within transposon Tn558) and 3 strains contained the tetracycline resistance gene [tet(K)]. Methicillin-susceptible Staphylococcus aureus strains were susceptible to most of the antibiotics studied and lacked the virulence genes of Panton-Valentine leukocidin (lukF/S-PV), toxic shock syndrome toxin 1 (tst), exfoliative toxin A (eta), and exfoliative toxin B (etb), as well as the genes of the immune evasion cluster. Methicillin-susceptible Staphylococcus aureus isolates were detected in a relatively low proportion of cows with mastitis (6.2%) and recovered isolates presented high diversity of genetic lineages, with CC1 and CC126 the predominant clonal complexes, and CC133 also being detected. Larger epidemiological studies with molecular characterization of isolates are required to deepen the knowledge on the circulating genetic lineages among the cow population with mastitis.

Alkaline phosphatase isoenzymes for the diagnosis of metastatic tumors and lymphomas of liver and bone.

The plasmatic activities of total alkaline phosphatase (ALP) (E.C. 3.1.3.1), high molecular weight-ALP (high Mr-ALP) and bone-ALP isoenzymes, were determined in healthy individuals and in patients with: neoplasia without metastases, hepatic metastases, bone metastases and mixed metastases (hepatic and bone). Variables were individually used to assess incidence of metastases and percentages of false negative and false positive results were calculated. The three values were then used together to assess metastases incidence and sensitivity, specificity, positive predictive value, negative predictive value and predictive capacity were estimated. We conclude that none of the variables per se are reliable for the diagnosis of metastases. On the other hand, the three values show high percentages of sensitivity, specificity, positive predictive value, negative predictive value and a high probability (0.93) of accurate diagnosis when applied to a larger population, with similar prevalence values.

Alkaline phosphatase isoenzymes for the diagnosis of metastatic tumors and lymphomas of liver and bone.

The plasmatic activities of total alkaline phosphatase (ALP) (E.C. 3.1.3.1), high molecular weight-ALP (high Mr-ALP) and bone-ALP isoenzymes, were determined in healthy individuals and in patients with: neoplasia without metastases, hepatic metastases, bone metastases and mixed metastases (hepatic and bone). Variables were individually used to assess incidence of metastases and percentages of false negative and false positive results were calculated. The three values were then used together to assess metastases incidence and sensitivity, specificity, positive predictive value, negative predictive value and predictive capacity were estimated. We conclude that none of the variables per se are reliable for the diagnosis of metastases. On the other hand, the three values show high percentages of sensitivity, specificity, positive predictive value, negative predictive value and a high probability (0.93) of accurate diagnosis when applied to a larger population, with similar prevalence values.

Biometría de la arteria cerebelar anterior-inferior en el segmento pontino-anterior y lateral / Biometry of the anterior-inferior cerebellar artery in its anterior pontine and lateral segments

Las intervenciones quirúrgicas realizadas en la fosa posterior del cráneo requieren de un detallado conocimiento anatómico. Con el propósito de complementar los datos obtenidos en trabajos previos, realizamos un estudio anatómico macro y mesoscópico de la arteria cerebelar anterior inferior (ACAI) enfocado en los segmentos pontino-anterior y lateral, que permitan conocer mejor esta región y en especial de su vascularización. La investigación se realizó en 70 encéfalos de cadáveres de individuos adultos, de ambos sexos, en los laboratorios de la Disciplina de anatomía Descriptiva y topografíca de la Universidad Federal de sao Pauli-Escola de Medicina/Brasil. Los encéfalofueron inyectados con látex neopreno teñidos de rojo y fijados en formol al 10 por ciento. previamente, se realizó un registro antropólogico del cráneo en cada uno de los individuos. El calibre de la ACAI, en el lado derecho y en ambos sexos, se encontraba frecuentemente entre 1.0-1.5 mm; este rango se presentó en el 47.4 por ciento de los braquicéfalos (BH) y en el 53.1 por ciento en los dólico-mesocéfalos (DM). En el lado izquierdo, se presentó en el 45.3 por ciento de los individuos de sexo masculino y en el 64.3 por ciento de los sexo femenino. Esto mismo se presentó en el 52.7 por ciento de los BH y en el 53.1 por ciento de los DM. El trayecto de la arteria, en el lado derecho, era ventral al nervio abducente en el 68.0 por ciento de los DM y en el 69.0 por ciento de los BH; en el lado izquierdo se observó en el 74.0 por ciento de los DM y en el 77.0 por ciento de los BH. Se insiste en la variabilidad de los patrones arteriales, cuando se considera además del lado y sexo, parámetros como el índice cefálico

Determination of alkaline phosphatase isozymes in amniotic fluid.

A simple method for the determination of the three isozymes of alkaline phosphatase (EC 3.1.3.1) contained in amniotic fluid (fetal intestinal, placental, and liver-bone-kidney) is presented. Total alkaline phosphatase activity was assayed in 10,000 g supernatants of amniotic fluid from 30 normal women between the 16th and 20th week of pregnancy. Electrophoretic patterns and inhibition by L-phenylalanine and L-homoarginine studies showed that all the fetal intestinal isozyme was precipitated in the pellet after centrifugation at 100,000 g for 90 min. Thus, the difference between total alkaline phosphatase activity and activity in the 100,000 g supernatant corresponds to fetal intestinal alkaline phosphatase. Placental isozyme can be determined by assaying alkaline phosphatase in the 100,000 g supernatant after heating at 56 degrees C for 90 min. Liver-bone-kidney isozyme activity is obtained by subtracting placental alkaline phosphatase activity from that of the 100,000 g supernatant. Mean percentages of the total alkaline phosphatase for each of the isozymes in amniotic fluid were 81% for fetal intestinal alkaline phosphatase, 7.5% for placental alkaline phosphatase and 12.0% for liver-bone-kidney alkaline phosphatase. Determination of fetal intestinal alkaline phosphatase by this method could be applied to the diagnosis of cystic fibrosis in fetuses having a 1:4 risk of being affected.

Miositis osificante progresiva congénita: A propósito de un caso revisión de la literatura / Congenital progressive myositis osifficant: Apropos of a case and review of literature

La miositis osificante progresiva es una enfermedad rara caracterizada por la formación de áreas de calcificación en el tejido conectivo intersticial de músculos, tendones, ligamentos, fascias y aponeurosis que pueden ser detectadas radiológicamente. Aunque las manifestaciones de la enfermedad pueden no ser evidentes hasta después de los diez años de vida, está asociada a ciertas anomalías congénitas como acortamiento de los pulgares hallux valgus y clinodactilia. El curso de la enfermedad es progresivo causando anquilosis, invalidez e incluso la muerte. El tratamiento es discutido, en la actualidad el etidronato disódico y la prednisona son los medicamentos más utilizados con resultados poco alentadores. Presentamos el caso de una niña de 2 años y 10 meses con manifestaciones clínicas de un año de evolución, nódulos calcificantes en diferentes sitios del cuerpo y limitación severa a la movilización del cuello y cintura escapular, inicialmente diagnosticada como dermatomiositis. Se enfatizan los hallazgos radiológicos y anatomopatológicos, así como la importancia de evitar los traumatismos y procedimientos invasivos como medida preventiva en estos niños

Effect of sympathetic denervation of the pineal gland on maternal co-ordination of the circadian rhythm of alpha-amylase in parotid gland from young rats.

Twenty-five-day-old rats maintained in constant darkness since birth and born from mothers kept in the dark since the 14th day of pregnancy showed a circadian rhythm of alpha-amylase content in parotid glands, which may be explained by a mechanism of maternal co-ordination. Rats in the same conditions, except that their mothers had been submitted to bilateral excision of the superior cervical ganglia 30 days before mating, did not show diurnal variations of alpha-amylase activity in the parotid glands. When ganglionectomized mothers were treated with a daily dose of melatonin (1 mg/kg) from the 14th day of gestation up to the 10th day of lactation, their litters showed significant diurnal variations of amylase in the parotid glands, suggesting a role of the maternal pineal gland in the maternal-fetal and/or maternal-neonatal transfer of photoperiodic information.

Alpha-amylase circadian rhythm of young rat parotid gland: an endogenous rhythm with maternal coordination.

The circadian rhythm of alpha-amylase, E.C. 3.2.1.1. alpha-1,4-glucan-4-glucanohydrolase) in the parotid glands of 25-day-old rats were studied under different experimental designs (fasting, reversed photoperiod, constant lighting conditions and treatment with reserpine and alpha-methyl-p-tyrosine). The rhythm of fasted rats did not change. There were modifications in the rhythm of rats submitted to a reversed photoperiod or treated with reserpine or alpha-methyl-p-tyrosine. The rhythm was present, with changes in the acrophase, in parotids of rats kept during their gestation and postnatal life in constant light or dark. Results suggest that the circadian rhythm of alpha-amylase in parotid gland of young rats is endogenous, synchronized by the photoperiod, and with maternal coordination.

Circadian rhythm of alpha-amylase in rat parotid gland.

The circadian rhythm of alpha-amylase, E.C. 3.2.1.1. (alpha-1,4-glucan-4-glucanohydrolase) in parotid gland of 25 day old rats was studied under different experimental conditions (fast, reversed photoperiod, constant light or darkness and treatment with reserpine and alpha-methyl-p-tyrosine). The rhythm of rats fasted or exposed for 7 days to constant darkness did not change. There were modifications in the rhythm of rats submitted to a reversed photoperiod and it disappeared in animals submitted to constant light or darkness for 15 days or treated with reserpine or alpha-methyl-p-tyrosine. The rhythm persisted, with minor changes in the acrophase, in parotids of rats kept during their gestation and post-natal life in constant light or darkness. Results suggest that the circadian rhythm of alpha-amylase in parotid gland of young rats is endogenous, synchronized by the photoperiod, under autonomous nervous system control and maternal coordination. This model appears to be useful in the study of sympathetic nervous system control of target organs and circadian rhythms in general.

Circadian rhythm of alpha-amylase in rat parotid gland.

The circadian rhythm of alpha-amylase, E.C. 3.2.1.1. (alpha-1,4-glucan-4-glucanohydrolase) in parotid gland of 25 day old rats was studied under different experimental conditions (fast, reversed photoperiod, constant light or darkness and treatment with reserpine and alpha-methyl-p-tyrosine). The rhythm of rats fasted or exposed for 7 days to constant darkness did not change. There were modifications in the rhythm of rats submitted to a reversed photoperiod and it disappeared in animals submitted to constant light or darkness for 15 days or treated with reserpine or alpha-methyl-p-tyrosine. The rhythm persisted, with minor changes in the acrophase, in parotids of rats kept during their gestation and post-natal life in constant light or darkness. Results suggest that the circadian rhythm of alpha-amylase in parotid gland of young rats is endogenous, synchronized by the photoperiod, under autonomous nervous system control and maternal coordination. This model appears to be useful in the study of sympathetic nervous system control of target organs and circadian rhythms in general.

Circadian rhythm of alpha-amylase in rat parotid gland

The circadian rhythm of alpha-amylase, E.C. 3.2.1.1. (alpha-1,4-glucan-4-glucanohydrolase) in parotid gland of 25 day old rats was studied under different experimental conditions (fast, reversed photoperiod, constant light or darkness and treatment with reserpine and alpha-methyl-p-tyrosine). The rhythm of rats fasted or exposed for 7 days to constant darkness did not change. There were modifications in the rhythm of rats submitted to a reversed photoperiod and it disappeared in animals submitted to constant light or darkness for 15 days or treated with reserpine or alpha-methyl-p-tyrosine. The rhythm persisted, with minor changes in the acrophase, in parotids of rats kept during their gestation and post-natal life in constant light or darkness. Results suggest that the circadian rhythm of alpha-amylase in parotid gland of young rats is endogenous, synchronized by the photoperiod, under autonomous nervous system control and maternal coordination. This model appears to be useful in the study of sympathetic nervous system control of target organs and circadian rhythms in general.

Effects of continuous light on rat parotid gland structure and reactivity.

The effects of continuous light on ultrastructural organization and sympathetic secretory responses of the rat parotid gland are reported. After 50 days of continuous light exposure, the fine structure of the parotid gland exhibited features of enhanced secretory activity as judged by the striking development of rough endoplasmic reticulum and Golgi complexes, the depletion of secretory granules and the increased turnover of secretory cells. The secretory responses of parotid gland to isoproterenol revealed that continuous light induced a 30% increase in amylase release. This secretory hyperactivity appears to be related to a postsynaptic supersensitivity of sympathetic fibers of the autonomic nervous system.