Compensatory responses in the aging hippocampal serotonergic system following neurodegenerative injury with 5,7-dihydroxytryptamine

This study utilized a multidisciplinary approach to examine injury-induced compensatory responses in the aging hippocampal serotonin transporter (5-HTT), a membrane protein implicated in a variety of neurodegenerative disorders. Age-dependent cellular, anatomical, and physiological changes of the 5-HTT were evaluated in female Fischer 344 rats (2 and 17 months) following denervation of the serotonergic afferents (fimbria-fornix and cingulum bundle) to the dorsal hippocampus using the neurotoxicant 5,7-dihydroxytryptamine (5,7-DHT). Seven days following 5,7-DHT administration, a uniform loss of the hippocampal 5-HTT immunoreactivity was observed in both age groups. However, at 21 days 5-HTT immunoreactivity in young 5,7-DHT-treated animals was similar to control levels, indicative of recovery, while older animals exposed to 5,7-DHT did not show recovery of hippocampal 5-HTT expression. 5-HTT binding site density, as determined by quantitative autoradiography ([3H]citalopram), supported the immunohistochemical results by demonstrating a recovery of 5-HTT binding sites in young, but not old animals, at 21 days following the lesion (P < 0.001). Furthermore, cellular electrophysiological function of hippocampal CA1 pyramidal neurons in 3- and 18-month-old F344 rats at 21 days following 5,7-DHT or vehicle treatment were assessed using in vivo microiontophoretic application of serotonin (5-HT). Independent of changes in sensitivity to the inhibitory effects of 5-HT application, the time to recovery of cell firing following application of 5-HT was significantly increased in the 18-month 5,7-DHT group compared to the 18-month vehicle and 3-month 5,7-DHT groups (60 and 59% increases, respectively; P < 0.05). Overall, these series of studies comprise a model which can be used to identify cellular events underlying both the formation of injury-induced compensatory processes in younger animals and the lack thereof with advancing age.

Parenteral supplementation with a fish-oil emulsion prolongs survival and improves rat lymphocyte function during sepsis

Nutritional intervention with omega-3 fatty acids during trauma and infection has been shown to improve the clinical outcome of patients and the survival rate in laboratory animals. This study evaluated the effects of parenteral administration of lipid emulsions containing fish oil (FO) or soybean oil (SBO) on survival and T-lymphocyte response during sepsis. Male Sprague-Dawley rats (250-275 g) were prepared for parenteral feeding 4 d before inducing sepsis by cecal ligation and puncture (CLP). Standard resuscitation was provided with normal saline. Thirty minutes after completing CLP, sham control or CLP rats were infused continuously with saline or a parenteral diet containing SBO or a 1:1 FO:SBO emulsion. The survival rate was significantly improved in rats receiving the FO-supplemented diet, with 50% alive by 120 h in comparison with the saline-infused, chow-fed rats (0% alive by 120 h) or the SBO-fed rats (12% alive at 120 h). The T-lymphocyte response was evaluated at 24 h after CLP. Sepsis led to a decline in lymphocyte proliferation in rats infused with saline or the SBO emulsion, which was associated with a greater release of splenocyte interleukin-10, transforming growth factor-beta and prostaglandin E2. Administering the 1:1 FO:SBO parenteral diet during sepsis improved the survival rate and prevented the sepsis-induced suppression of lymphocyte proliferation and interleukin-2 release. The FO effect on lymphocyte function was associated with decreased splenocyte release of transforming growth factor-beta and prostaglandin E2.

The levels of TNF alpha, IL4 and IL10 production by T-cells in B-cell chronic lymphocytic leukaemia (B-CLL)

Tumour necrosis factor alpha (TNF alpha), interleukin (IL) 4 and IL10 are important for the growth and survival of the leukaemic cells in B-cell chronic lymphocytic leukaemia (B-CLL). The present study investigates the production of TNF alpha, IL4 and IL10 in patients with B-CLL. Significant increases in the TNF alpha and IL4 mean levels compared to normal control CD2(+)-cells were observed for B-CLL lymphocytes (TNF alpha: P=0.0004 and IL4: P=0.0026). By contrast, the mean level of IL10 produced by purified B-CLL CD2(+)-cells was significantly lower than that seen with normal control T-cells (P=0.0136). No significant difference in the percentage (%) of T-cells that expressed cytoplasmic TNF alpha, IL4 and IL10 was observed between B-CLL and normal T-cells. However, a significant increase in the mean level of intracellular TNF alpha and IL4 expression was observed in B-CLL compared with normal control T-cells (TNF alpha: P=0.031; IL4: P=0.0027). The increased expression of cytoplasmic TNF alpha and IL4 appeared to be associated with increased cytokine production in the tested samples. The differences observed with some B-CLL cases in the production of TNF alpha, IL4 and IL10 by peripheral blood T-cells may suggest survival mechanisms for the leukaemic cells in these patients.

Accuracy of cancer-risk assessment in primary care practice

BACKGROUND

Primary care physicians (PCPs) are expected to play a central role in assessing cancer risk. This study was designed to evaluate how accurately PCPs would triage individuals at increased risk for cancer when presented with clinical vignettes.

METHODS

Surveys evaluated practice demographics, attitudes, and responses to clinical scenarios. Answers were compared with guidelines and graded for consistency with the risk assessment.

RESULTS

PCPs were inaccurate in assessing risk (p < 0.0001) and inconsistent in recommending screening (p < 0.001). Older physicians were more consistent (p < 0.02). No attitudinal bias was identified.

CONCLUSION

Continuing education of PCPs is important for cancer-risk assessment and management.

Using a web-based prototype and human-computer interaction concepts to develop a vision for a next generation patient care management system

This paper describes the novel use of two tools to develop requirements for a new generation patient care system: a web-based prototype and a human-computer interaction framework. These tools allowed a development team to crystallize new requirements for a patient care system, illustrate to clinicians a radical change in care process models, and begin the change management process in a large enterprise.

The N terminus of p53 regulates its dissociation from DNA

It is important to gain insight into p53 DNA binding and how it is regulated. By using electrophoretic mobility shift assays and DNase I footprinting, we show that a region within the N terminus of the protein controls the dissociation of p53 from a p53-binding site. When p53 is bound by a number of N-terminal-specific monoclonal antibodies, its rate of dissociation from DNA is reduced, and its ability to protect a cognate site from DNase I digestion is increased. Moreover, greatly reduced dissociation is observed with p53 protein lacking the N-terminal 96 amino acids. By contrast, deletion of the C terminus does not affect p53 dissociation from DNA or DNase I protection. p53 protein expressed in and purified from bacterial cells displays markedly more instability on its consensus DNA-binding site than does p53 produced in insect cells, suggesting that post-translational modifications may affect the stability of the protein. Our results provide evidence that the N terminus of p53 possesses an auto-inhibitory function that is mechanistically different from the inhibitory region at the C terminus.

Conventional high resolution versus fast T(2)-weighted MR imaging of the heart: assessment of reperfusion induced myocardial injury in an animal model

Cardiac image quality in terms of spatial resolution and signal contrast was assessed for conventional and newly developed T(2)-weighted fast spin-echo imaging with high k-space segmentation. The capability in revealing regional myocardial edema and cellular damage was examined by a porcine model using histopathologic correlation. Twelve porcine hearts were excised from slaughtered animals and instantly perfused with 1000 mL cold cardioplegic solution. After 4 h of cold ischemia the hearts were reperfused for one hour using a "Langendorff" perfusion model followed by MR imaging at 1.5 Tesla. Three additional pig hearts served as controls and were studied by MR directly after harvesting. Histopathological analysis of regional tissue changes was performed macro- and microscopically. Short axis T(2)-weighted (3000/45 and 90) high quality fast spin-echo (FSE) images were recorded without cardiac action and signal intensity was correlated with histology. These images also served as gold standard for evaluation of newly developed faster sequences allowing measuring times shorter than 20 s. Fast T(2)-weighted imaging comprised single-slice fast spin echo (moderate echo train length of 23 echoes, FSE(m)), and multi-slice single-shot half-Fourier fast spin-echo (71 echoes, FSE(HASTE)) sequences, supplemented by versions with inversion recovery preparation (FSE(m)IR and FSE(HASTE)IR). Systolic function after reperfusion was restored in 10 porcine hearts. Tissue alterations included myocardial edema and contraction band necrosis which was found to be most severe in myocardium with maximum T(2) SI. Especially FSE(m) and FSE(m)IR sequences allowed differentiation of all categories of tissue damage on a high level of significance. In contrast, single-shot FSE(HASTE) and FSE(HASTE)IR sequences did not provide sufficient image quality to discriminate moderate and severe myocardial damage (p > 0.05). Different degrees of myocardial injury after ischemia and reperfusion can be staged by MR imaging, especially using conventional high resolution T(2)-weighted FSE sequences. The animal study indicates that fast T(2)-weighted FSE(m) and FSE(m)IR sequences lead to superior image quality and diagnostic accuracy compared to FSE(HASTE) and FSE(HASTE)IR imaging.

Identification of an ancillary protein, YabF, required for activity of the KefC glutathione-gated potassium efflux system in Escherichia coli

A new subunit, YabF, for the KefC K(+) efflux system in Escherichia coli has been identified. The subunit is required for maximum activity of KefC. Deletion of yabF reduces KefC activity 10-fold, and supply of YabF in trans restores activity. IS2 and IS10R insertions in yabF can be isolated as suppressors of KefC activity consequent upon the V427A and D264A KefC mutations.

Multimodal versus progressive treatment techniques to correct burn scar contractures

The treatment of burn scar contractures is a major emphasis in the rehabilitation of patients with burn injuries. Many treatment techniques have been used successfully but without a critical investigation of the best practice of care. In this study, we compared the outcomes for pediatric and adult patients treated with a multimodal therapy approach to treatment techniques that are considered to be progressive to determine if differences existed in the techniques. The medical records of 52 patients with documented burn scar contractures were reviewed for patient and rehabilitation treatment parameters. Included were population demographic information and type of treatment intervention used to correct the scar contracture. In particular, the postburn day when the contracture appeared, the percentage of range of motion deficit, the day when definitive treatment that eventually corrected the contracture was begun, and the days required to correct the contracture were noted. With equal range-of-motion deficits identified, the burn scar contractures of patients in the progressive treatment group were corrected in less than half the time of the burn scar contractures of the patients in the multimodal treatment group. This result occurred despite scar contractures that appeared significantly earlier and later initiation of definitive treatment.

Functional aerobic impairment in adolescents seropositive for HIV: a quasiexperimental analysis

OBJECTIVE

To determine the degree to which cardiorespiratory insufficiency limits physical performance in adolescents seropositive for human immunodeficiency virus (HIV).

DESIGN

Quasiexperimental, case series design.

SETTING

Rehabilitation physiology laboratory.

PARTICIPANTS

Seventeen adolescents (12 women, 5 men; age, 18 +/- 2 yr; weight, 74.7 +/- 19.3 kg; height, 170 +/- 9 cm) with HIV infection (viral load, 22,043 +/- 55,869 copies/mL; CD4 count, 499 +/- 210/mL) who were free of comorbid conditions limiting treadmill performance.

MAIN OUTCOME MEASURES

Spirometric measurements of oxygen uptake and anaerobic threshold obtained from a peak exercise treadmill test using the modified Bruce protocol.

RESULTS

Measured peak oxygen consumption (VO2) was 42% +/- 19% lower than expected (p < .025), suggesting a significant functional aerobic impairment (FAI) or peak VO2 less than 73% of expected values. Peak VO2 was only slightly higher (p < .05) than the oxygen uptake requirements for the most intense activities of daily living (ADL). Anaerobic threshold was only slightly higher (p < .05) than minimum ADL intensities.

CONCLUSIONS

Cardiorespiratory insufficiency and FAI limited the ability to perform even low levels of physical activity in these adolescents with mild HIV seropositivity. Disability identified by quantification of FAI may affect implementation of the American with Disabilities Act and public health policy.

A gender-specific intervention for at-risk women in the USA

Women are the fastest growing group in the USA to become infected with HIV. Also, the mode of transmission is changing with heterosexual behaviour being the predominant source. As these changes occur, HIV infection becomes more common in women who have not typically been considered at high risk. This paper describes an intervention designed to decrease unsafe sexual encounters and to focus on a highly meaningful concern in the lives of these women: relationships with men. The sessions encouraged making decisions, choice, partner selection, sexual rights, refusal of any unwanted sex, female controlled methods and other elements of empowerment. An eight-session and a four-session curriculum were created to assess dose factors as well.

Bone cancers in Mayak workers

Bone cancer mortality risks were evaluated in 11,000 workers who started working at the "Mayak" Production Association in 1948-1958 and who were exposed to both internally deposited plutonium and external gamma radiation. Comparisons with Russian and U.S. general population rates indicate excess mortality, especially among females, plutonium plant workers, and workers with external doses exceeding 1 Sv. Comparisons within the Mayak worker cohort, which evaluate the role of plutonium body burden with adjustment for cumulative external dose, indicate excess mortality among workers with burdens estimated to exceed 7.4 kBq (relative risk = 7.9; 95% CI = 1.6-32) and among workers in the plutonium plant who did not have routine plutonium monitoring data based on urine measurements (relative risk = 4.1; 95% CI = 1.2-14). In addition, analyses treating the estimated plutonium body burden as a continuous variable indicate increasing risk with increasing burden (P < 0.001). Because of limitations in current plutonium dosimetry, no attempt was made to quantify bone cancer risks from plutonium in terms of organ dose, and risk from external dose could not be reliably evaluated.

Liver cancers in Mayak workers

Liver cancer mortality risks were evaluated in 11,000 workers who started working at the "Mayak" Production Association in 1948-1958 and who were exposed to both internally deposited plutonium and external gamma radiation. Comparisons with Russian liver cancer incidence rates indicate excess risk, especially among those with detectable plutonium body burdens and among female workers in the plutonium plant. Comparisons within the Mayak worker cohort which evaluate the role of plutonium body burden with adjustment for cumulative external dose indicate excess risk among workers with burdens estimated to exceed 7.4 kBq (relative risk = 17; 95% CI = 8. 0-36) and among workers in the plutonium plant who did not have routine plutonium monitoring data based on urine measurements (relative risk = 2.8; 95% CI = 1.3-6.2). In addition, analyses treating the estimated plutonium body burden as a continuous variable indicate increasing risk with increasing burden (P < 0.001). Relative risks tended to be higher for females than for males, probably because of the lower baseline risk and the higher levels of plutonium measured in females. Because of limitations in current plutonium dosimetry, no attempt was made to quantify liver cancer risks from plutonium in terms of organ dose, and risk from external dose could not be reliably evaluated.

Efficacy and safety of repeated samarium-153 lexidronam treatment in a patient with prostate cancer and metastatic bone pain

A patient with stage D3 prostate cancer was given 11 separate doses of samarium-153 lexidronam (Sm-153 ethylenediaminetetramethylene phosphonate) of 1 mCi/kg (37 MBq/kg) in a period of 28 months for bone pain from metastases. With the first five doses, Sm-153 lexidronam clearly reduced his bone pain and improved his quality of life, as determined by pain-assessment scores and the patient's self-assessment of its effect on his ability to perform activities of daily living. With doses 6 through 11, pain at baseline was on average less, and as a result beneficial effects after treatment were not as apparent. Samarium-153 lexidronam produced transient decreases in the leukocyte and platelet counts, but these never became low enough to cause clinical concern. This case shows both the efficacy and the safety of Sm-153 lexidronam in repeated treatments for metastatic bone pain in patients with prostate cancer.

Reversed-phase high-performance liquid chromatography combined with on-line UV diode array, FT infrared, and 1H nuclear magnetic resonance spectroscopy and time-of-flight mass spectrometry: application to a mixture of nonsteroidal antiinflammatory drugs

A prototype multiply hyphenated system has been applied to the analysis of a mixture of nonsteroidal antiinflammatory drugs separated by reversed-phase HPLC. Characterization of the model NSAIDs was achieved via a combination of diode array UV, 1H NMR, FT-IR spectroscopy, and time-of-flight mass spectrometry. This combination of spectrometers allowed the collection of UV, 1H NMR, IR, and mass spectra together with atomic composition data enabling almost complete structural characterization to be performed.

Resolution of Ga-67 citrate uptake in the left neck mass of Hodgkin's disease and reversion of double scoliosis of cervical-thoracic and lower lumbar vertebrae

A 6-yr-old boy underwent a total body Ga-67 citrate imaging study because of a large mass of Hodgkin's lymphoma in the left neck and the left anterior chest wall region. The images showed intense uptake in the left neck extending anteroinferiorly to the left upper chest wall corresponding to the left neck and chest region. In addition, there was mild cervical-upper thoracic scoliosis with convexity to the right and mild scoliosis of the lower lumbar scoliosis with concavity to the left. After three cycles of chemotherapy, in the follow-up Ga-67 citrate total body images seven months after his first Ga-67 citrate imaging, the intense uptake in the left neck and the left upper chest wall had been resolved and the scoliosis of the cervical-thoracic and lower lumbar spine had also been reversed to normal. This case shows that a Ga-67 citrate imaging study is useful for first diagnosis and subsequent monitoring of the therapeutic effects in a follow-up imaging. Also Ga-67 citrate imaging provided evidence that the scoliosis had been reversed.

Inverted arcuate osteotomy and external fixation for adolescent tibia vara

The purpose of our review is to describe and report results of a surgical technique for the treatment of adolescent Blount's disease. We retrospectively reviewed the results of 15 inverted arcuate osteotomies combined with external fixation. The inverted arc provides a proximal and stable osteotomy that can correct deformity in three planes. External fixation provides stable fixation, access to surgical wounds, and postoperative adjustment. According to the criteria of Schoenecker, we had 80% good results. Two patients with poor results were the most overcorrected, suggesting that overcorrection may not be so desirable as once suggested. We conclude that the inverted arcuate osteotomy with external fixation is an effective, reliable, and simple technique for treating adolescent tibia vara.

[Variability in the MR tomographic determination of myocardial function and perfusion parameters in health subjects]

PURPOSE

The aim of the study was to evaluate myocardial function and perfusion patterns using magnetic resonance imaging in normal subjects.

MATERIALS AND METHODS

22 healthy volunteers were examined. Cine-mode acquisitions along all three axes of the heart were generated and perfusion was measured on a mid-ventricular short-axis view. Myocardial wall thickening was scored and contrast enhancement during the first pass was analysed.

RESULTS

For myocardial wall thickening increasing values from base (24-86%) to apex (63-106%) were found. Contrast enhancement patterns showed regional variability. In addition marked individual differences were detectable.

CONCLUSION

Perfusion patterns should be interpreted only in combination with functional parameters. Standard values for perfusion measurements cover very large range as a result of the high individual variability.

Heparin-binding proteins are involved in thrombin time variability in normal and patient plasmas

The ability of plasma proteins to neutralize the anticoagulant activity of heparin was studied using a thrombin time assay with 20 normal adult and 207 patient plasma samples. The thrombin times of normal adult plasmas spiked with the same amount of heparin were found to vary significantly, and this variability was attributed to differences in heparin-binding proteins among individuals. This possibility was investigated by determining thrombin times for a variety of plasma samples following proteolytic digestion. A study of patient pooled plasma showed that incubation with a protease increased the thrombin time from 23 s to > 300 s, suggesting that the anticoagulant activity of heparin could be neutralized by plasma proteins and released with proteolytic digestion. Incubation of the digested plasma with heparinase I returned the thrombin time almost to control values. In addition, patients who received prior heparin injections had different responses to similar dosages of heparin, as indicated by differences in thrombin times. Thus, the anticoagulant activity of heparin may be affected by the balance between free heparin and protein-bound heparin in plasma.

Osteogenic protein-1 prevents renal fibrogenesis associated with ureteral obstruction

Unilateral ureteral obstruction (UUO) is a model of renal injury characterized by progressive tubulointerstitial fibrosis and renal damage, while relatively sparing the glomerulus and not producing hypertension or abnormalities in lipid metabolism. Tubulointerstitial fibrosis is a major component of several kidney diseases associated with the progression to end-stage renal failure. Here we report that when a critical renal developmental morphogen, osteogenic protein-1 (OP-1; 100 or 300 microg/kg body wt), is administered at the time of UUO and every other day thereafter, interstitial inflammation and fibrogenesis are prevented, leading to preservation of renal function during the first 5 days after obstruction. Compared with angiotensin-converting enzyme inhibition with enalapril treatment, OP-1 was more effective in preventing tubulointerstitial fibrosis and in preserving renal function. The mechanism of OP-1- induced renal protection was associated with prevention of tubular atrophy, an effect not shared with enalapril, and was related to preservation of tubular epithelial integrity. OP-1 blocked the stimulation of epithelial cell apoptosis produced by UUO, which promoted maintenance of tubular epithelial integrity. OP-1 preserved renal blood flow (RBF) during UUO, but enalapril also stimulated RBF. Thus OP-1 treatment inhibited tubular epithelial disruption stimulated by the renal injury of UUO, preventing tubular atrophy and diminishing the activation of tubulointerstitial inflammation and fibrosis and preserving renal function.