Renal blood flow regulation, autoregulation, and vasomotor nephropathy

Renal blood flow and renal perfusion pressure are regulated by two control mechanisms. The first, extrinsic, actually involves a complex interaction of vasomotor effects between opposing neurohormonal systems. The second, intrinsic mechanism, renal autoregulation, depends on changes in afferent arteriolar tone in response to the renal perfusion pressure itself. This article reviews these two mechanisms, how they normally respond to stress, and the clinical implications of certain situations in which these control mechanisms are disrupted.     

Higher than normal plasma interleukin-6 concentrations in cancer patients with depression: preliminary findings

OBJECTIVE: This study investigated whether cancer patients with and without major depression exhibit immune system abnormalities similar to those reported in medically healthy, depressed subjects without cancer. METHOD: The study subjects consisted of patients diagnosed with pancreatic, esophageal, or breast cancer. Other groups consisted of subjects with major depression (without cancer) and healthy comparison subjects. Subjects' diagnoses were made with the Structured Clinical Interview for DSM-III-R. Severity of depression was measured with the Hamilton Depression Rating Scale. Plasma concentrations of interleukin-6 (IL-6) and postdexamethasone cortisol were measured. RESULTS: Cancer patients with depression had markedly higher plasma concentrations of IL-6 than healthy comparison subjects and cancer patients without depression. Although significant correlations were found between Hamilton depression scale scores and plasma concentrations of postdexamethasone cortisol, no significant correlations were found between plasma IL-6 and postdexamethasone cortisol concentrations. CONCLUSIONS: Higher than normal plasma IL-6 concentrations were associated with a diagnosis of major depression in cancer patients. IL-6 may contribute to sickness behavior that has overlapping symptoms with major depression.     

Introducing an evaluation of community based occupational therapy services: a client-centred practice

The results of a study conducted in 1996 by the "Groupe de recherche en ergothérapie communautaire" (GREC), indicate that the quality of occupational therapy services in community settings is infrequently evaluated. A conceptual framework supporting such a process is presented in the context of client-centered services with a focus on continuous health care improvement. Both the research process leading to the design of an assessment tool, and its congruence with the beliefs and values of the profession, are explored. Finally, some issues relating to the implementation of a formal evaluation process are discussed.     

Sensitivity of Escherichia coli (MutT) and human (MTH1) 8-oxo-dGTPases to in vitro inhibition by the carcinogenic metals, nickel(II), copper(II), cobalt(II) and cadmium(II)

The toxicity of Ni(II), Co(II) and Cu(II) in animals, and that of Cd(II) in cultured cells, has been associated with generation of the promutagenic lesion 8-oxo-7,8-dihydroguanine (8-oxoguanine) in DNA, among other effects. One possible source of this base may be 8-oxo-7,8- dihydro-2'-deoxyguanosine-5'-triphosphate (8-oxo-dGTP), a product of oxidative damage to the nucleotide pool, from which it is incorporated into DNA. To promote such incorporation, the metals would have to inhibit specific cellular 8-oxo-dGTPases that eliminate 8-oxo-dGTP from the nucleotide pool. The present study was designed to test such inhibition in vitro on 8-oxo-dGTPases from two different species, the human MTH1 protein and Escherichia coli MutT protein. In the presence of Mg(II), the natural activator of 8-oxo-dGTPases, all four metals were found to inhibit both enzymes. For MTH1, the IC50 values (+/- SE; n = 3-4) were 17 +/- 2 microM for Cu(II), 30 +/- 8 microM for Cd(II), 376 +/- 71 microM for Co(II) and 801 +/- 97 microM for Ni(II). For MutT, they were 60 +/- 6 microM for Cd(II), 102 +/- 8 microM for Cu(II), 1461 +/- 96 microM for Ni(II) and 8788 +/- 1003 microM for Co(II). Thus, Cu(II) and Cd(II) emerged as much stronger inhibitors than Ni(II) and Co(II), and MTH1 appeared to be generally more sensitive to metal inhibition than MutT. Interestingly, in the absence of Mg(II), the activity of the enzymes could be restored by Co(II) to 73% of that with Mg(II) alone for MutT, and 34% for MTH1, the other metals being much less or non-effective. The difference in sensitivity to metal inhibition between the two enzymes may reflect the differences in the amino acid ligands, especially the cysteine ligand, outside their evolutionarily conserved Mg(II)-binding active sites, which might indicate predominantly non-competitive or uncompetitive mechanism of the inhibition. The overall results suggest that inhibition of 8-oxo- dGTPases may be involved in the mechanisms of induction of the 8- oxoguanine lesion in DNA by the metal ions studied, especially the non- redox-active Cd(II) cation.      

Sexuality education in fifth and sixth grades in U.S. public schools, 1999

CONTEXT: While policymakers, educators and parents recognize the need for family life and sexuality education during children's formative years and before adolescence, there is little nationally representative information on the timing and content of such instruction in elementary schools. METHODS: In 1999, data were gathered from 1, 789 fifth- and sixth-grade teachers as part of a nationally representative survey of 5,543 public school teachers in grades 5-12. Based on the responses of 617 fifth- and sixth-grade teachers who said they teach sexuality education, analyses were carried out on the topics and skills sexuality education teachers taught, the grades in which they taught them, their teaching approaches, the pressures they experienced, whether they received support from parents, the community and school administrators, and their needs. RESULTS: Seventy-two percent of fifth- and sixth-grade teachers report that sexuality education is taught in their schools at one or both grades. Fifty-six percent of teachers say that the subject is taught in grade five and 64% in grade six. More than 75% of teachers who teach sexuality education in these grades cover puberty, HIV and AIDS transmission and issues such as how alcohol and drugs affect behavior and how to stick with a decision. However, when schools that do not provide sexuality education are taken into account, even most of these topics are taught in only a little more than half of fifth- and sixth-grade classrooms. All other topics are much less likely to be covered. Teaching of all topics is less prevalent at these grades than teachers think it should be. Gaps between what teachers say they are teaching and teachers' recommendations for what should be taught and by what grade are especially large for such topics as sexual abuse, sexual orientation, abortion, birth control and condom use for STD prevention. A substantial proportion of teachers recommend that these topics be taught at grade six or earlier. More than half (57%) of fifth- and sixth-grade sexuality education teachers cover the topic of abstinence from intercourse--17% as the only option for protection against pregnancy and STDs and 40% as the best alternative or one option for such protection. Forty-six percent of teachers report that one of their top three problems in teaching sexuality education is pressure, whether from the community, parents or school administrators. More than 40% of teachers report a need for some type of assistance with materials, factual information or teaching strategies. CONCLUSIONS: A large proportion of schools are doing little to prepare students in grades five and six for puberty, much less for dealing with pressures and decisions regarding sexual activity Sexuality education teachers often feel unsupported by the community, parents or school administrators.     

Cardiac rhabdomyomas and their association with tuberous sclerosis

A search for children presenting with signs or symptoms of cardiac rhabdomyomas was made through members of the paediatric section of the British Cardiac Society in order to establish their birth incidence, presenting features, clinical course, and the frequency of a concurrent diagnosis of tuberous sclerosis. Fifteen children were identified and 12 had tuberous sclerosis (80%). Heart failure was the presentation in six, five of whom died; six presented because of a murmur and three because of arrhythmias. The prevalence of echocardiographic evidence of cardiac rhabdomyomas in a population of patients with tuberous sclerosis was established. Twenty individuals had echocardiography and eight had echodensities consistent with cardiac rhabdomyomas. It is concluded that the minimum birth incidence for children presenting because of the effects of cardiac rhabdomyomas is 1/326,000 and a minimum of 80% have tuberous sclerosis. In a population of patients with tuberous sclerosis a minimum of 60% under 18 years have cardiac rhabdomyomas.     

Outcome of congenital lung abnormalities detected antenatally

To determine the outcome of congenital lung abnormalities, data were collected retrospectively between January 1991 and December 1996 on any foetus found to have a lung lesion on antenatal ultrasound. A total of 23 foetuses had lung lesions on antenatal ultrasound. In two foetuses the antenatal ultrasound showed bilateral enlarged "bright" echogenic lungs with evidence of hydrops. Both pregnancies were terminated and tracheal atresia was confirmed. In 15 foetuses the antenatal ultrasound appearance was of a unilateral "bright" echogenic lung. There was one case of bronchial atresia and two cases of congenital lobar emphysema, which all had surgery. In nine cases there was a reduction in the size of the lesion on serial antenatal ultrasounds and no lesion was detected after birth. In three cases a small lesion was present after birth on chest radiography. In six foetuses the antenatal ultrasound appearance was of unilateral cystic or mixed cystic and echogenic lung lesions. Two pregnancies were terminated; both had congenital cystic adenomatoid malformation. Four pregnancies were continued and three infants had surgery soon after birth and were confirmed to have had congenital cystic adenomatoid malformation. One infant has been managed conservatively. In conclusion, a definitive diagnosis cannot usually be made antenatally. A large lesion on initial scan does not necessarily predict a poor outcome. The natural history of small asymptomatic postnatal lesions is unknown and a long-term prospective study is needed to determine the outcome of these lesions.     

Inflicted traumatic brain injury: relationship of developmental outcome to severity of injury

Inflicted traumatic brain injury (TBI) is a frequent consequence of physical child abuse in infants and children. Twenty-eight children who were 2-42 months of age when hospitalized for moderate to severe TBI were enrolled in a prospective, longitudinal study of neurobehavioral outcome following acquired brain injury. Relative to a comparison group, the children with inflicted TBI had significant deficits in cognitive, motor and behavioral domains when assessed with the Bayley Scales of Infant Development-II 1 and 3 months after the injury. Nearly half of the injured children showed persisting deficits in attention/arousal, emotional regulation and motor coordination. Greater injury severity, as indicated by lower coma scale scores, longer periods of unconsciousness and the presence of edema/cerebral infarctions was associated with poorer outcomes in all domains.     

Role of phospholipase A2 and pertussis toxin-sensitive G proteins in histamine secretion induced by substance P

Incubation of mast cells with substance P or ionophore A23187 resulted in histamine release and arachidonic acid liberation from purified rat peritoneal mast cells. The treatment of mast cells with 100 ng/ml of pertussis toxin for 2h inhibited the effect of substance P on both histamine release and arachidonic acid liberation, but the response to the ionophore A23187 was not affected. Para-bromophenacyl bromide, a selective inhibitor of phospholipase A₂, inhibited similarly histamine and arachidonate release induced by substance P but not that evoked by ionophore A23187. These results suggest that phospholipase A₂ plays a key role in the histamine secretion induced by substance P.

     

Comparison of EDTA and acid-citrate-dextrose collection tubes for detection of cytomegalovirus antigenemia and infectivity in leukocytes before and after storage.

Duplicate blood samples collected in EDTA and acid-citrate-dextrose (ACD) were compared by cytomegalovirus (CMV) pp65 antigenemia and CMV infectivity on the day of sample collection and after 1 and 2 days of storage at 4 degrees C. No significant difference was detected between EDTA and ACD. However, CMV antigenemia was more sensitive than culture at all time points tested.