Biomedical subjects
R Russo
Publications and source records attributed to R Russo.
The heart of Broadway.
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[Leptospirosis: epidemiology, diagnosis and clinical aspects]
Leptospires, world-wide distributed spirochetes, affect a great variety of mammalian hosts; several serovars belonging to the L. interrogans s.l. species can cause clinical manifestations in humans, becoming infected through the contact of skin cuts and mucous membranes with water and soil polluted by infected animals' urine; rodents serve as the main reservoirs but the epidemiological importance of pets and cattle, as leptospire shedder is increasing. While the infection remains endemic in tropical regions, there is a new epidemiological trend in developed countries where, with the typical seasonal pattern, sporadic cases and/or outbreaks occur related more to recreational activities and poor sanitation than to occupational activities. The sudden onset presents a "flu-like" syndrome; the course is usually characterised by two clearly defined stages. All of the variable clinical manifestations, often independent of the responsible serovar, arise from the effects of a general vasculitis. The prognostic factors associated with severe forms (renal failure, jaundice, haemorrhagies) are not defined. Within the first days of illness, the leptospires can be isolated from blood and cerebrospinal fluid; serological diagnosis relies on microagglutination, IFA and ELISA; PCR early in the course, before the appearance of specific antibodies, allows etiological diagnosis. Prompt treatment has an enormous impact on outcome.
Inter-organ leptin exchange in humans.
To assess the individual role of splanchnic organs, kidney, and peripheral tissues on leptin metabolism, leptin exchange across the splanchnic bed, kidney, and leg has been evaluated by the arterio-venous technique in post-absorptive non-obese subjects. Leptin levels in the hepatic and renal veins were significantly lower (p < 0.001), while femoral vein levels were consistently greater (p < 0.05) than in the artery. The fractional extraction of leptin, namely the percentage of arterial leptin extracted, was greater in splanchnic organs (16%) than in the kidney (9.5%). Urinary excretion of leptin was undetectable in most subjects, indicating that leptin is degraded within the kidney. There was no correlation between fractional extraction of leptin and glomerular filtration rate, whereas leptin fractional extraction was directly related to renal plasma flow (p = 0.017). Renal leptin clearance was about 50% of the glomerular filtration rate. Our data demonstrate that both splanchnic organs and the kidney cooperate in the disposal of leptin, while peripheral tissues add significant amounts of leptin to the circulation. In non-obese subjects the contribution of the kidney to whole body clearance is no more than 50%. The removal of leptin by the kidney depends on renal plasma flow but not on glomerular filtration rate or filtered leptin.
Cross-cultural adaptation and validation of an Argentine Spanish Version of the Stanford Childhood Health Assessment Questionnaire.
OBJECTIVES: To translate into Argentine Spanish and cross-culturally adapt the Childhood Health Assessment Questionnaire (CHAQ) and validate the adapted instrument in Argentine patients with juvenile rheumatoid arthritis (JRA). METHODS: Five bilingual Argentine pediatric rheumatologists translated into Argentine Spanish and cross-culturally adapted the United States English CHAQ. Pretesting was done in a sample of 23 parents using a probe question technique. Parents of 70 patients with JRA and 21 healthy children (controls) participated in the validation phase. All were from Argentina. RESULTS: The mean disability index (DI) scores for patients with systemic, polyarticular, or pauciarticular onset JRA were 0.64, 0.32, and 0.1, respectively. Healthy controls averaged 0.2. Intercomponent correlations were between 0.4 and 0.9, suggesting internal consistency, but also some redundancy. Test-retest reliability, studied at a 1-week interval, was moderate (mean DI 0.44 [in clinic] and 0.29 [one week later], Pearson's correlation = 0.82). We compared CHAQ scores from 15 parents with those of their children > 10 years of age. Significantly higher DI scores were given by patients than their respective parents (P > 0.019), but the pairwise scores (parent-patient) were highly correlated (r = 0.986). CONCLUSIONS: Cross-cultural adaptation of the US CHAQ to Argentina required few changes. Although DI scores for all patient subgroups were higher than for controls subjects, the scores were low, particularly for those with pauciarticular disease. Prospective studies designed to examine the sensitivity to change and predictive validity will help to assess further the usefulness of the adapted CHAQ in the Argentine population.
Levels of processing and single word priming in amnesic and control subjects.
This paper describes an experiment which examined how levels of processing (LOP) affected word fragment completion in a group of Wernicke-Korsakoff patients, a group of patients with closed head injury, and matched controls. The data showed that both the memory-impaired groups and the controls showed a LOP effect but that the effect was larger in controls. Data from other studies are reviewed and, in conjunction with the present findings, it is concluded that LOP effects obtained when memory-impaired individuals are tested using implicit memory tasks arise mainly from the contribution of lexical processing of targets and from contamination by explicit recollection.
Study of the Bohr effect in hemoglobin intermediates.
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Somatostatin release in response to glucose is impaired in chronic renal failure.
In order to evaluate somatostatin (SRIH) secretion in uremia, plasma SRIH concentrations were determined in basal conditions and after an oral glucose tolerance test (OGTT) in 14 non-dialysed patients with chronic renal failure (CRF), seven of whom had normal glucose tolerance (NGT) and seven impaired glucose tolerance (IGT). Plasma insulin, C-peptide and glucagon and blood glucose concentrations were also evaluated. The results were compared with those obtained in a group of age- and sex-matched normal subjects. In CRF patients, plasma SRIH fasting values (8.6 +/- 0.6 and 7.8 +/- 0.6 pmol/L in NGT and IGT patients, respectively) were comparable to those recorded in controls (7.7 +/- 0.5 pmol/L). SRIH response to OGTT, evaluated as area under curves (AUC) above basal, was similar in both groups of CRF patients (412.9 +/- 84.5 and 415.6 +/- 51.9 pmol/L per min), and significantly lower than in controls (660.1 +/- 58.5 pmol/L per min). Data indicate that chronic uremia induces a loss of SRIH secretory cell responsiveness to glucose. A possible effect of impaired SRIH secretion on glucose metabolism in CRF is discussed.
Highly restricted expression at the ectoderm-endoderm boundary of PIHbox 9, a sea urchin homeobox gene related to the human HB9 gene.
Characterisation of a sea urchin (P. lividus) homeobox gene PIHbox 9 is reported. The homeodomain of PIHbox9 is 95% identical to the homeodomain of the human HB9 gene, indicating that the two genes are highly related. Temporal expression analysis during sea urchin embryogenesis showed an absence of transcripts at early cleavage stages. At late gastrula stage, transcripts were barely detectable and reached the highest abundance at prism/early pluteus stages. By whole mount in situ hybridisation we observed a highly restricted expression in a few cells of the ectoderm-endoderm boundary of embryos at the prism stage. At pluteus stages, expression of PIHbox 9 was confined around the anus.
Comparison of the homogeneity of breast dose distributions with and without the medial wedge.
Radiation of the intact breast often requires medial and lateral wedges to improve dose homogeneity of its pyramidal shape and to achieve acceptable cosmesis. There is some concern that radiation scatter from the medial wedge may contribute to cancer in the uninvolved breast, yet treatment without the medial wedge is associated with inhomogeneity of magnitudes that affect cosmesis. These homogeneities are identified on treatment plans generated at the central axis (CAX). It is not known if comparing isodose curves at the central axis reflect homogeneity in superior and inferior planes. A study was undertaken to both examine inhomogeneity with and without the medial wedge, and to determine if plan selection at the CAX was representative of homogeneity above and below the CAX. Ten consecutive patients with early breast cancers had cranial, CAX, and caudal CT images of each breast compared with two wedging conditions, lateral only (LW) and medial and lateral wedged conditions (dual wedges = DW). Dosimetry was optimized at the CAX for DW and LW conditions. Dose distributions and hot spots relative to prescribed dose were compared for cranial, CAX, and caudal images. Mean chest wall separations were measured. Six of ten patients had equivalent LW and DW distributions at the levels examined. Only one of these patients had a single off-axis hot spot > 20%. Six patients had comparable LW and DW dosimetry and acceptable hot spots at the central axis, as well as chest wall separations < or = 22 cm. In conclusion, if isodose configurations are commensurate at the CAX, these patients will have homogeneity above and below the CAX. In patients with chest wall separations < or = 22 cm, treatment without the medial wedge is feasible, sparing the contralateral breast dose with little compromise to inhomogeneity in the treated breast.
Revising current two-process accounts of spacing effects in memory.
Memory for repeated items improves when presentations are spaced during study. In Experiment 1A, words were repeated either immediately or after 6 intervening items. Intentional learning occurred under either focused or divided attention. Retention was tested by either free recall or yes-no recognition. Divided attention did not affect the influence of spacing in free recall, whereas it removed the spacing effect in recognition. In Experiment 1B, recognition memory was tested after incidental semantic study of words performed under either focused or divided attention. An equivalent spacing effect occurred in both attentional conditions. In Experiments 2 and 3, recognition memory for unfamiliar faces was assessed. A reliable spacing effect was found under both intentional learning and incidental structural study. These data are, collectively, incompatible with current theories of spacing effects. A theoretical proposal to account for these new findings is outlined.
Circadian antidiuretic hormone variation in elderly men complaining of persistent nocturia after urinary flow obstruction removal.
Persistence of nocturia after prostatic resection in healthy patients without symptoms referred to residual bladder instability and to pathological polyuria seems to be caused by an increased urine production at night. The more accreditate mechanism involved is the relevant decreased ADH secretion pattern which occurs at night. In our study, patients with nocturnal poliuria showed significantly low plasmatic vasopressin levels compared with a control group. The aim of this study was to evaluate whether the persistence of nocturia after prostatic resection in healthy patients, without symptoms referred due to residual bladder instability and important polyuria, could be due to a decrease or a lack of increase in antidiuretic hormone (ADH) nocturnal levels following increased urine production at night. Serum ADH, atrial natriuretic peptide (ANP) and osmolality were assessed at 4-h intervals in 12 patients complaining of residual nocturia (group A) and in a control group of 13 patients who had undergone a complete resolution of nocturia after prostate ablation (group B). In the 25 patients involved in the study (mean age 65.8 years), no significant differences were observed in the two groups concerning mean age (67.5 years for group A, 64 years for group B). Mean nocturnal urine volume (1080 +/- 490 ml) in group A patients was significantly higher than in group B (500 +/- 100 ml) (p < 0.001), while no significant differences were found in diurnal diuresis. Mean plasma vasopressin levels of the 12 patients showing an increased nocturnal micturition were found to be significantly lower at all 4-h intervals when compared with the control group (p < 0.05). Individual fluctuations in serum osmolality were slight and insignificant within the normal range in all patients. The diurnal variation of plasma atrial natriuretic peptide was within the reference limits for all subjects during the 24-h period. Our results lead us to believe that residual nocturia after prostatic resection seems to be caused by an increased urine production at night due to a decreased ADH secretion pattern.
Impaired vasorelaxant responses to natriuretic peptides in the stroke-prone phenotype of spontaneously hypertensive rats.
BACKGROUND: We have previously shown that a locus on rat chromosome 5, termed STR 2, co-localizes with the genes encoding atrial natriuretic and brain natriuretic peptides, and is closely linked to the development of strokes in rats of a F2 hybrid cohort obtained by crossing stroke-prone spontaneously hypertensive rats and spontaneously hypertensive rats. We also demonstrated that there are significant differences in vascular functioning that are co-segregated with stroke latency of stroke-prone spontaneously hypertensive rats. OBJECTIVE: To investigate the vascular responses to natriuretic peptides in the stroke-prone phenotype of spontaneously hypertensive rats. DESIGN AND METHODS: In view of the important vasoactive properties of natriuretic peptides, we tested the vascular responses to 10(-11)-10(-9) mol/l atrial natriuretic peptide and to 10(-11)-10(-7) mol/l brain natriuretic peptide in isolated rings of aortas and internal carotid arteries obtained from stroke-prone and stroke-resistant spontaneously hypertensive rats. The 6-week-old rats were exposed for 4 weeks either to their regular diet (n = 15 of both strains) or to the stroke-permissive Japanese-style diet (n = 14 of both strains). A group of 14 normotensive, age-matched and sex-matched Wistar-Kyoto rats was also studied. RESULTS: Systolic blood pressures in stroke-prone and stroke-resistant spontaneously hypertensive rats were similar, and were significantly higher than those in Wistar-Kyoto rats. Vascular responses to nitroglycerin, atrial natriuretic peptide, and brain natriuretic peptide in rats of the two hypertensive strains and in Wistar-Kyoto rats fed their regular diet were comparable. In contrast, the vasorelaxant responses to atrial natriuretic peptide in stroke-prone spontaneously hypertensive rats fed Japanese diet were lower both in aortas and in internal carotid arteries than were those in spontaneously hypertensive rats (both P < 0.05 by analysis of variance) and in Wistar-Kyoto rats (both P < 0.05). Similarly, vasorelaxant responses to brain natriuretic peptide were lower both in aortas and in internal carotid arteries of stroke-prone spontaneously hypertensive rats than they were in spontaneously hypertensive rats (both P < 0.05) and in Wistar-Kyoto rats (P < 0.05). The responses to nitroglycerin in the stroke-prone spontaneously hypertensive rats and spontaneously hypertensive rats fed Japanese-style diet were also similar. CONCLUSION: The vasorelaxant effects of natriuretic peptides are impaired in stroke-prone spontaneously hypertensive rats. This abnormality could play a role in the pathogenesis of stroke incidence in this hypertensive model.
Consequences of violating the assumption of independence in the process dissociation procedure: a word fragment completion study.
In three experiments that used levels of processing and study time manipulations as independent variables in a word fragment completion task, the validity of the assumption of independence between recollection and automatic influences of memory was assessed. This assumption underlies the use of the process dissociation procedure (Jacoby, 1991), a tool suggested for distinguishing the different contributions of recollection and automatic influences of memory. Overall, it appeared that semantic processing, as compared with physical processing at study, positively affected recollection but negatively affected automatic influences of memory in word fragment completion. This negative effect on the automatic influences was reduced when the available study time decreased. The incompatibility of these results with the assumption of independence between recollection and automatic influences of memory and their impact on the applicability of the process dissociation procedure are discussed.
Healthcare compliance plans: good business practice for the new millennium.
Recent developments indicate that government scrutiny of healthcare providers will continue well into the next century. This article sheds light on the Federal False Claims Act and its recent interpretation by the Department of Health and Human Services' Office of the Inspector General and the United States Attorney's Office, the OIG's 1998 workplan, and current fraud and abuse initiatives. It also presents the fundamental elements of a compliance plan.
[Social determinants and risk of acute viral hepatitis].
The authors examined the relationship between viral hepatitis risk and social determinants in Piedmont region population surveyed by SEIEVA (sistema epidemiologico integrato dell'epatite virale acuta). The education and the working position showed different correlation with incidence rates of different types of viral hepatitis A, B, non-A non-B. The hepatitis A risk is proportional to education and the probability of hepatitis B and non-A non-B is higher in low social classes. This situation is only apparently a balanced risk: the clinical seriousness and the strong probability of complications of hepatitis B and non-A non-B make the risks deeply unequal.
Nine more cases of human infections by Dirofilaria repens diagnosed in Italy by morphology and recombinant DNA technology.
Dirofilariosis is a mosquito-borne disease of carnivors due, in Italy, to Dirofilaria repens and D. immitis species which are sympatric in many areas. Nine more cases of human infection are here reported, detected in Italian patients living in northern regions (where D. immitis and D. repens are largely present), in Tuscany (where D. repens is more frequent than D. immitis), and in Sicily (where D. immitis is present only sporadically). The nematodes surgically removed (7 female and 2 male specimens) have been identified by a PCR-based method and by morphology as D. repens. Morphological, clinical, and epidemiological data of these human infections are discussed.