Postnatal nutritional treatment of neurocognitive deficits in fetal alcohol spectrum disorder.

Ethanol is the most important teratogen agent in humans. Prenatal alcohol exposure can lead to a wide range of adverse effects, which are broadly termed as fetal alcohol spectrum disorder (FASD). The most severe consequence of maternal alcohol abuse is the development of fetal alcohol syndrome, defined by growth retardation, facial malformations, and central nervous system impairment expressed as microcephaly and neurodevelopment abnormalities. These alterations generate a broad range of cognitive abnormalities such as learning disabilities and hyperactivity and behavioural problems. Socioeconomic status, ethnicity, differences in genetic susceptibility related to ethanol metabolism, alcohol consumption patterns, obstetric problems, and environmental influences like maternal nutrition, stress, and other co-administered drugs are all factors that may influence FASD manifestations. Recently, much attention has been paid to the role of nutrition as a protective factor against alcohol teratogenicity. There are a great number of papers related to nutritional treatment of nutritional deficits due to several factors associated with maternal consumption of alcohol and with eating and social disorders in FASD children. Although research showed the clinical benefits of nutritional interventions, most of work was in animal models, in a preclinical phase, or in the prenatal period. However, a minimum number of studies refer to postnatal nutrition treatment of neurodevelopmental deficits. Nutritional supplementation in children with FASD has a dual objective: to overcome nutritional deficiencies and to reverse or improve the cognitive deleterious effects of prenatal alcohol exposure. Further research is necessary to confirm positive results, to determine optimal amounts of nutrients needed in supplementation, and to investigate the collective effects of simultaneous multiple-nutrient supplementation.

The mutagenesis of a type IV secretion system locus of Piscirickettsia salmonis leads to the attenuation of the pathogen in Atlantic salmon, Salmo salar.

Piscirickettsiosis is a threatening infectious disease for the salmon industry, due to it being responsible for significant economic losses. The control of outbreaks also poses considerable environmental challenges. Despite Piscirickettsia salmonis having been discovered as the aetiological agent of the disease more than 25 years ago, its pathogenicity remains poorly understood. Among virulence factors identified so far, type four secretion systems (T4SS) seem to play a key role during the infection caused by the bacterium. We report here the genetic manipulation of P. salmonis by means of the transference of plasmid DNA in mating assays. An insertion cassette was engineered for targeting the icmB gene, which encodes a putative T4SS-ATPase and is carried by one of the chromosomal T4SS clusters found within the genome of P. salmonis PM15972A1, a virulent representative of the EM-90-like strain. The molecular characterization of the resulting mutant strain demonstrated that the insertion interrupted the target gene. Further in vitro testing of the icmB mutant showed a dramatic drop in infectivity as tested in CHSE-214 cells, which is in agreement with its attenuated behaviour observed in vivo. Altogether, our results demonstrate that, similar to other facultative intracellular pathogens, P. salmonis' virulence relies on an intact T4SS.

Clinical and mutational features of X-linked agammaglobulinemia in Mexico.

X-linked agammaglobulinemia (XLA) is caused by BTK mutations, patients typically show <2% of peripheral B cells and reduced levels of all immunoglobulins; they suffer from recurrent infections of bacterial origin; however, viral infections, autoimmune-like diseases, and an increased risk of developing gastric cancer are also reported. In this work, we report the BTK mutations and clinical features of 12 patients diagnosed with XLA. Furthermore, a clinical revision is also presented for an additional cohort of previously reported patients with XLA. Four novel mutations were identified, one of these located in the previously reported mutation refractory SH3 domain. Clinical data support previous reports accounting for frequent respiratory, gastrointestinal tract infections and other symptoms such as the occurrence of reactive arthritis in 19.2% of the patients. An equal proportion of patients developed septic arthritis; missense mutations and mutations in SH1, SH2 and PH domains predominated in patients who developed arthritis.

Genomic-enabled prediction with classification algorithms.

Pearson's correlation coefficient (ρ) is the most commonly reported metric of the success of prediction in genomic selection (GS). However, in real breeding ρ may not be very useful for assessing the quality of the regression in the tails of the distribution, where individuals are chosen for selection. This research used 14 maize and 16 wheat data sets with different trait-environment combinations. Six different models were evaluated by means of a cross-validation scheme (50 random partitions each, with 90% of the individuals in the training set and 10% in the testing set). The predictive accuracy of these algorithms for selecting individuals belonging to the best α=10, 15, 20, 25, 30, 35, 40% of the distribution was estimated using Cohen's kappa coefficient (κ) and an ad hoc measure, which we call relative efficiency (RE), which indicates the expected genetic gain due to selection when individuals are selected based on GS exclusively. We put special emphasis on the analysis for α=15%, because it is a percentile commonly used in plant breeding programmes (for example, at CIMMYT). We also used ρ as a criterion for overall success. The algorithms used were: Bayesian LASSO (BL), Ridge Regression (RR), Reproducing Kernel Hilbert Spaces (RHKS), Random Forest Regression (RFR), and Support Vector Regression (SVR) with linear (lin) and Gaussian kernels (rbf). The performance of regression methods for selecting the best individuals was compared with that of three supervised classification algorithms: Random Forest Classification (RFC) and Support Vector Classification (SVC) with linear (lin) and Gaussian (rbf) kernels. Classification methods were evaluated using the same cross-validation scheme but with the response vector of the original training sets dichotomised using a given threshold. For α=15%, SVC-lin presented the highest κ coefficients in 13 of the 14 maize data sets, with best values ranging from 0.131 to 0.722 (statistically significant in 9 data sets) and the best RE in the same 13 data sets, with values ranging from 0.393 to 0.948 (statistically significant in 12 data sets). RR produced the best mean for both κ and RE in one data set (0.148 and 0.381, respectively). Regarding the wheat data sets, SVC-lin presented the best κ in 12 of the 16 data sets, with outcomes ranging from 0.280 to 0.580 (statistically significant in 4 data sets) and the best RE in 9 data sets ranging from 0.484 to 0.821 (statistically significant in 5 data sets). SVC-rbf (0.235), RR (0.265) and RHKS (0.422) gave the best κ in one data set each, while RHKS and BL tied for the last one (0.234). Finally, BL presented the best RE in two data sets (0.738 and 0.750), RFR (0.636) and SVC-rbf (0.617) in one and RHKS in the remaining three (0.502, 0.458 and 0.586). The difference between the performance of SVC-lin and that of the rest of the models was not so pronounced at higher percentiles of the distribution. The behaviour of regression and classification algorithms varied markedly when selection was done at different thresholds, that is, κ and RE for each algorithm depended strongly on the selection percentile. Based on the results, we propose classification method as a promising alternative for GS in plant breeding.

[Granulomatous appendicitis caused by sarcoidosis: report of one case]. / Apendicitis granulomatosa sarcoidal: una infrecuente entidad clínico-patológica. Caso clínico.

Granulomatous appendicitis is uncommon and can be caused by Crohn's disease, foreign body reactions, infections or sarcoidosis. We report a 26-year-old female consulting in the emergency room for pain in the right lower abdomen. She was released with analgesics and consulted 14 days later for the same pain. This time she was operated with the preoperative diagnosis of appendicitis. The pathological study of the surgical piece was compatible with a granulomatous appendicitis caused by sarcoidosis.

A novel in-vitro model of intervertebral disc degeneration using hyperphysiological loading.

Intervertebral disc (IVD) degeneration includes changes in tissue biomechanics, physical attributes, biochemical composition, disc microstructure, and cellularity, which can all affect the normal function of the IVD, and ultimately may lead to pain. The purpose of this research was to develop an in-vitro model of degeneration that includes the evaluation of physical, biomechanical, and structural parameters, and that does so over several load/recovery periods. Hyperphysiological loading was used as the degenerative initiator with three experimental groups employed using bovine coccygeal IVD specimens: Control; Single-Overload; and Double-Overload. An equilibrium stage comprising a static load followed by two load/recovery periods was followed by six further load/recovery periods. In the Control group all load/recovery periods were the same, comprising physiological cyclic loading. The overload groups differed in that hyperphysiological loading was applied during the 4th loading period (Single-Overload), or the 4th and 5th loading period (Double-Overload). Overloading led to a significant reduction in disc height compared to the Control group, which was not recovered in subsequent physiological load/recovery periods. However, there were no significant changes in stiffness. Overloading also led to significantly more microstructural damage compared to the Control group. Taking all outcome measures into account, the overload groups were evaluated as replicating clinically relevant aspects of moderate IVD degeneration. Further research into a potential dose-effect, and how more severe degeneration can be replicated would provide a model with the potential to evaluate new treatments and interventions for different stages of IVD degeneration.

Clinical, molecular and biochemical characterization of nine Spanish families with Conradi-Hünermann-Happle syndrome: new insights into X-linked dominant chondrodysplasia punctata with a comprehensive review of the literature.

BACKGROUND: Conradi-Hünermann-Happle syndrome (CDPX2, OMIM 302960) is an inherited X-linked dominant variant of chondrodysplasia punctata which primarily affects the skin, bones and eyes. CDPX2 results from mutations in EBP (emopamil binding protein), and presents with increased levels of sterol precursors 8(9)-cholesterol and 8-dehydrocholesterol. OBJECTIVES: To expand the understanding of CDPX2, clinically, biochemically and genetically. METHODS: We present one of the largest series reported to date, including 13 female patients belonging to nine Spanish families. Patients were studied biochemically using gas chromatography-mass spectrometry, genetically using polymerase chain reaction and in their methylation status using the HUMARA assay. RESULTS: In our cases, there was a clear relationship between abnormal sterol profile and the EBP gene mutation. We describe three novel mutations in the EBP gene. EBP mutations were inherited in three out of nine families and were sporadic in the remaining cases. CONCLUSIONS: No clear genotype-phenotype correlation was found. Patients' biochemical profiles did not reveal a relationship between sterol profiles and severity of disease. A skewed X-chromosome inactivation may explain the clinical phenotype in CDPX2 in some familial cases.

[Brain hydatidosis: report of four cases]. / Hidatidosis cerebral: aspectos clínicos e imagenológicos. Reporte de 4 casos.

In only 2% of all cases of hydatidosis, the cysts are located in the brain. We report a 12-year-old male, a 5-year-old girl and a 19-year-old female consulting for intracranial hypertension and a 13-year-old male consulting for a left hemiparesis. Imaging studies found intra-cerebral cysts with characteristics of hydatidosis in all. All lesions were completely removed surgically and the pathological study of the excised piece confirmed the diagnosis of hydatidosis.

[Blastic plasmocytoid dendritic cell neoplasm: Report of one case]. / Neoplasia blástica de células dendríticas plasmocitoides: Caso clínico.

BACKGROUND: We report a 74 years old male consulting for multiple painless non pruriginous pink plaques and nodules of truncal distribution that appeared 15 days earlier. A skin biopsy disclosed a blastic plasmocytoid dendritic cell neoplasm. A staging CAT scan showed lymphadenopathies located around the trachea and its bifurcation. A bone marrow biopsy did not show tumor infiltration. The patient has been treated with four cycles of cyclophosphamide-doxorubicin-vincristine-prednisone, obtaining a partial remission of the lesions.

In-vitro models of disc degeneration - A review of methods and clinical relevance.

The intervertebral disc (IVD) provides flexibility, acts as a shock absorber, and transmits load. Degeneration of the IVD includes alterations in the biomechanics, extracellular matrix (ECM), and cellular activity. These changes are not always perceived, however, IVD degeneration can lead to severe health problems including long-term disability. To understand the pathogenesis of IVD degeneration and suitable testing methods for emerging treatments and therapies, this review documents in-vitro models of IVD degeneration including physical disruption, hyperphysiological loading, ECM degradation by enzyme digestion, or a combination of these methods. This paper reviews and critically analyses the models of degeneration published since the year 2000 in either in human or animal specimens. The results are categorised in terms of the IVD biomechanics, physical attributes, ECM composition, tissue damage and cellularity to evaluate the models with respect to natural human degeneration, and to provide recommendations for clinically relevant models for the various stages of degeneration. There is no one model that replicates the wide range of degenerative changes that occur as part of normal degeneration. However, cyclic overloading replicates many aspects of degeneration, with the advantage of a dose-response allowing the tuning of damage initiated. Models of severe degeneration are currently lacking, but there is potential that combining cyclic overloading and enzymatic digestion will provide model that closely resembles human IVD degeneration. This will provide an effective way to investigate the effects of severe degeneration, and the evaluation of treatments for the IVD, which would generally be indicated at this advanced stage of degeneration.

[Large cell calcifying Sertoli cell tumor: report of one case]. / Tumor de células de Sertoli calcificante, de células grandes: caso clínico.

Sertoli cell tumors are less than 1% of all testicular tumors. We report a 14-year-old male presenting with a left testicular mass. Orchiectomy was carried out and the pathological study informed a large cell calcifying Sertoli cell tumor (LCCSCT). Its association with the Carney complex and Peutz-Jeghers syndrome was subsequently discarded. Surgical excision was completed with a radical orchiectomy. After eight months of follow up, there is no evidence of tumor relapse.

[Prognostic value of extracapsular lymph node involvement among patients with gastric cancer]. / Compromiso ganglionar extracapsular en pacientes con cáncer gástrico: determinación del valor pronóstico.

BACKGROUND: Extracapsular lymph node involvement has a negative prognosis in malignant tumors. AIM: To assess the prognostic importance of extracapsular lymph node involvement in patients with gastric cancer with lymph node metastases. MATERIAL AND METHODS: Clinical and morphological features and survival of patients with gastric cancer and lymph node involvement operated between 1986 and 2003, were analyzed. Patients with and without extracapsular involvement were compared. RESULTS: During the study period, 459 gastrectomies were performed, 312 patients (68%) had lymph node involvement and 144 (31%) had extracapsular involvement. Patients with and without extracapsular involvement were followed for a median of 10 (range 1 to 120) and 41 (range 1 to 193) months, respectively. Five years actuarial survival for patients with and without extracapsular involvement was 23 and 40% respectively. Extracapsular lymph node involvement and level of wall infiltration were identified as prognostic factors using a multivariate analysis. CONCLUSIONS: Extracapsular lymph node involvement is an independent risk factor for mortality among patients with gastric cancer.

[Tungiasis. Report of one case]. / Tungiasis: una rara ectoparasitosis. Caso clínico.

We report a 54-year-old male that, after working in a rural zone of Rio de Janeiro, Brazil, presented with an itching cutaneous lesion in the wrist with a black small central zone. The patient extracted from the lesion a on of 0.5 mm diameter. The pathological study of the insect recognized its body segments. The epidemiological background and the characteristics of the lesion led to the diagnosis of tungiasis.

[Primary cutaneous mucormycosis: two case reports and review of the literature]. / Mucormicosis cutánea primaria: a propósito de dos casos. Revisión de la literatura.

Mucormycosis or zygomycosis is a rare opportunistic infection caused by aerobic saprophytic fungus that belongs to the class of Zygomycetes Mucorales family. These organisms live in the environment and enter the body by air, gastrointestinal or skin routes, through solutions of continuity of the skin. This microorganism is generally not pathogenic for immunocompetent hosts, being the development of the disease linked with the immune status of the subject. Its mortality is around 50-60%; sometimes in spite of early diagnosis and treatment initiation it has a fatal course. Six clinical forms of mucormycosis are described: rhinocerebral, cutaneous, pulmonary, disseminated, gastrointestinal and miscellaneous form. Two cases of patients with primary cutaneous mucormycosis diagnosed in the Pathology Unit of Hernan Henriquez Aravena Hospital of Temuco, Chile are presented here.

[Morphological findings in fatal cases of hantavirus cardiopulmonary syndrome. Report of 7 autopsies]. / Hallazgos morfológicos en casos fatales de síndrome cardiopulmonar por hantavirus. Estudio de 7 autopsias.

INTRODUCTION: Hantavirus cardiopulmonary syndrome (HCPS) is an acute infectious disease characterized by sudden cardiorespiratory failure and high mortality, caused by a RNA virus of the genus Hantavirus, family Bunyaviridae, 15% of Chilean cases have been detected in the Araucania Region. OBJECTIVE: To determine in fatal cases of HCPS, clinical and morphological characteristics. MATERIALS AND METHODS: Descriptive-retrospective analysis of seven fatal cases with postmortem study of HCPS, attended between 1997 and 2009 at the Hospital of Temuco, Chile. RESULTS: Cases were young patients from rural areas, and presented as an illness of progressive respiratory failure, with leukocytosis, thrombocytopenia and bilateral interstitial pulmonary infiltrates. Main morphological findings were marked intersticial and intraalveolar pulmonary edema, with minimal epithelial injury and mononuclear cell intersticial infiltrate and mild edematous intersticial inflamatory process. CONCLUSIONS: Epidemiological, clinical and laboratory background allow to suspect HCPS. In fatal cases, the autopsy makes possible to discard other similar pathologies and provide tissue for confirmation of the disease.

Impact of an intervention for reducing waste through educational strategy: A Mexican case study, what works, and why?

Generation and inadequate management of solid waste constitute a global challenge. Projections for 2050 portend an annual increase of 3.40 billion tons of waste. This study assessed the impact of an environmental education intervention (EEI) aimed at reducing waste generation and fomenting pro-environmental behaviors in an academic public-health institution in Mexico. The EEI was implemented over 20 months using a model of behavior change. Using a mixed-method design (QUAN + qual), baseline and follow-up measurements were performed through electronic questionnaires (n = 754), focus groups (n = 20), and waste quantification. A double-difference model was performed to measure pro-environmental behaviors impact: overall and by sex, age, educational level and function within the institution. Waste quantification was performed using a quartering method and weekly monitoring. The qualitative data were studied through thematic analysis. As a result of the EEI, women reduced their use of multilayer packaging (-15.6 pp, p < 0.05) and frequent use of non-ecological materials (-17.6 pp, p < 0.05). Graduate-level participants reduced their regular and frequent use of these materials (-33.3 pp, p < 0.05, 27.6 pp, p < 0.01), while those with lower educational levels increased their ecological behavior at home (12.1 pp, p < 0.05). Waste generation dropped by 60.1% vis-a-vis the baseline measurement. Our qualitative findings showed a relationship between holding a position of power in the institution and recycling. They also revealed that available infrastructure for separating waste contributed substantially to the observed impact. With actions centered on physical structure, community practice and institutional policy components, the EEI improved the pro-environmental behaviors and perceptions of participants.

Effects of angiotensin-converting enzyme inhibition on altered renal hemodynamics induced by low protein diet in the rat.

We assessed the role of angiotensin II in mediating the alterations in renal hemodynamics known to result from low protein feeding to normal rats by examining the effect of the angiotensin-converting enzyme (ACE) inhibitor captopril. 2 wk of low protein (6% casein) diet resulted in decreased glomerular filtration rate (normal protein [NP], 1.82 +/- 0.17 vs. low protein [LP], 0.76 +/- 0.01 ml/min; P less than 0.05) and renal plasma flow (NP, 6.7 +/- 0.2 vs. LP, 3.3 +/- 0.3 ml/min; P less than 0.05); renal vascular resistance rose (NP, 8.7 +/- 0.4 vs. LP, 19.8 +/- 1.4 dyn . s per cm5; P less than 0.05). These changes were accompanied by a significant decrease in plasma renin activity (NP, 7.0 +/- 0.7 vs. LP, 4.4 +/- 0.8 ng A I/ml per h; P less than 0.05), plasma aldosterone concentration (NP, 7.0 +/- 0.6 vs. LP, 4.1 +/- 0.7 ng/dl; P less than 0.05), and urinary PGE2 excretion (NP, 3,120 +/- 511 vs. LP, 648 +/- 95 pg/mgCr; P less than 0.05); by contrast renal renin content was significantly increased (NP, 2,587 +/- 273 vs. LP, 7,032 +/- 654 ng A I/mg protein; P less than 0.05). Treatment with captopril (30 mg/kg per d) raised glomerular filtration rate (GFR; LP + capt, 1.6 +/- 0.2 ml/min) and renal plasma flow (RPF; LP + capt, 6.7 +/- 0.7 ml/min), and reduced renal vascular resistance (LP + capt, 9.2 +/- 0.5 dyn/s per cm5) in low protein-fed animals. These values were not different from those measured in untreated and captopril-treated rats fed a normal (23%) protein diet. There were no changes in systemic mean arterial pressure in any group of rats. These data provide evidence that intrarenal angiotensin II mediates the changes in intrarenal hemodynamics induced by protein deprivation. The effects of low protein feeding may be partly potentiated by the reduction in PGE2 synthesis. However, the normalization of GFR and RPF in view of only modest increases in PGE2 excretion after captopril (LP, 648 +/- 95 vs. LP + capt, 1,131 +/- 82 pg/mgCr; P less than 0.05) suggests that if PGE2 is involved in these changes, it plays a permissive but not essential role in the increased renovascular resistance.

Repercusión de la pandemia COVID-19 en la actividad pediátrica en Atención Primaria / Impact of the COVID-19 pandemic on the pediatric activity in Primary Care

Introducción. La pandemia por COVID-19 ha supuesto un cambio en nuestras vidas y deseamos conocer su influencia en las consultas de pediatría en Atención Primaria. Pacientes y métodos. Estudio observacional retrospectivo de la actividad en un Centro de Salud urbano entre enero 2019 y marzo 2021. Se realiza aleatorización estratificada para elegir semana y día y se incluyen todos los pacientes. La información se extrae del programa Medora. Se recogen las variables: fecha de consulta, fecha de nacimiento, profesional, sexo, patología crónica, tipo y motivo de consulta, hospitalización reciente y afectación por COVID-19. Se realiza un análisis de regresión logística binaria y análisis de regresión de joinpoint. Resultados. La muestra es de 1.802 consultas. La tendencia de las tasas de consultas es estable de forma global y en la atención de enfermería, pero hay cambios estacionales en la atención de los pediatras. Durante la pandemia el tipo de consulta a la demanda/urgencia ha sido inferior que la programada (Odds Ratio = 0,19, IC al 95%: 0,1 a 0,3) y la atención telefónica/no presencial superior a la programada (Odds Ratio = 4,01: IC95% 2,3 a 6,95). El comportamiento de las consultas por tipo de patologías, consulta de revisión, vacunaciones o aspectos administrativos ha sido similar antes y durante la pandemia. Conclusión. El volumen de atenciones en nuestro Centro de Salud ha sido similar durante el periodo estudiado. La atención telefónica/no presencial ha sido cuatro veces superior a la consulta programada. Existen diferencias estacionales con descenso estival (AU)

Introduction. Our aim is to know the impact of the pandemic on pediatric activity in Primary Care.Patients and methods. Retrospective observational study of pediatric activity in an urban Health Center between January 2019 and March 2021. Stratified randomization is performed to choose the week and day. All patients are included. The information collected is extracted from the Medora program. Date of consultation, date of birth, professional, sex, chronic pathology, type and reason for consultation, recent hospitalization and involvement by COVID-19 are collected. Binary logistic regression analysis and regression analysis of joinpoint are performed.Results. The sample is made up of 1802 consultations. Trend in consultation rates is stable globally and in nursing care, but there are seasonal changes in pediatric care. During the pandemic, the demand/urgent consultation was lower than scheduled (Odds Ratio = 0.19, 95% CI 0.1 to 0.3) and telephone/non-face-to-face consultations were higher than scheduled (Odds Ratio = 4.01: 95% CI 2.3 to 6.95). The behavior of consultations by type of pathology, review consultation, vaccinations or administrative aspects has been similar before and during the pandemic.Conclusion. The number of consultations in our Health Center has been similar along the studied period. Telephone/non-face-to-face assistance has been four times higher thanscheduled consultation. There are seasonal differences in pediatric care with a summer decline (AU)

Role of macula densa in diuretics-induced renin release.

Diuretic therapy may enhance renin release by various mechanisms, principally contraction of extracellular fluid volume and its effects, including a fall in arterial pressure. Awake hydropenic or volume-expanded rats received diuretics (amiloride and hydrochlorothiazide) that are known inhibitors of NaCl transport beyond the macula densa; also the well-known Na(+)-K(+)-2 Cl- transport system inhibitor furosemide was administered. We also evaluated the effect of a dose of ethacrynic acid (a drug that shares the same mechanism of action as furosemide but is not diuretic in the rat). The direct action of the diuretics on renin-producing cells was examined in isolated glomeruli; a rise in renin release was observed with the calmodulin inhibitor trifluoperazine (10(-5) M). Renin release in intact hydropenic rats was not altered by diuretic therapy, but furosemide increased plasma renin activity in hydropenic as well as in volume-expanded rats. This demonstrates the importance of furosemide inhibition of transport in the macula densa for its renin secretory action. None of the diuretics (amiloride, hydrochlorothiazide, ethacrynic acid, or furosemide) elicited changes in renin release from glomeruli (10(-6) to 10(-3) M); amiloride and hydrochlorothiazide (10(-4) to 10(-3) M) did not change renin release from slices, but 10(-3) M ethacrynic acid and furosemide increased renin secretion in this preparation. This suggests that an effect on the macula densa is essential in loop diuretic-mediated renin release.(ABSTRACT TRUNCATED AT 250 WORDS)

Glomerular hemodynamics in persistent renovascular hypertension in the rat.

We studied the glomerular hemodynamics and activity of the tubuloglomerular feedback system (TGFS) in Wistar rats with persistent hypertension 60 days after removal of the clipped kidney in the Goldblatt (two-kidney, one clip) hypertension model. Ten hypertensive rats (HBP) were compared with 12 normotensive ones (NBP). Micropuncture studies revealed that values for the single nephron glomerular filtration rate (SNGFR), glomerular plasma flow (QA), and afferent oncotic pressure (PAR.A) were similar in both groups, whereas glomerular capillary pressure (PGC) and effective filtration pressure (EFP) were higher in the HBP group (p less than 0.05). A slight but insignificant increase in afferent resistance was present in the HBP group. A positive correlation was found between mean arterial pressure and stop flow pressure (SFP) (r = 0.64, p less than 0.05) but not with SNGFR, suggesting a reduction in the ultrafiltration coefficient in hypertensive rats. This was further supported by studies of the activity of the TGFS, which demonstrated that interrupting flow to the macula densa was followed by a smaller increment in SNGFR in HBP, in spite of a similar rise in SFP. The mechanism responsible for decreasing glomerular permeability is unknown but could be related to structural changes in glomerular capillary or to an increase in intrarenal angiotensin II, as has been demonstrated previously in this model. It is suggested that these adaptations occurring in the kidney exposed to hypertension can contribute to the maintenance of elevated arterial pressure after removing the stenotic kidney.