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Biomedical subjects

H Hill

Publications and source records attributed to H Hill.

At least 19 recordsLinked to original sources
PubMed2005

[Duodenal ileus due to an intramural duodenal haematoma. Conservative therapy using a multiple lumen intestinal probe].

HISTORY AND ADMISSION FINDINGS: A 68-year-old woman was admitted with upper abdominal symptoms, epigastric fullness and nausea, eight days after initiation of heparin anticoagulation for deep-vein thrombosis. There were no other clinical abnormalities. INVESTIGATIONS: Abdominal ultrasound and computed tomography showed an intramural duodenal haematoma. Endoscopy revealed a stenosing lesion in the duodenum. TREATMENT AND COURSE: Instead of conventional parenteral nutrition, a triple-lumen feeding tube was placed, one lumen in the jejunum for feeding, the other for gastric decompression. Six months later the symptoms had completely disappeared and ultrasound, endoscopy and computed tomography no longer detected any lesion. CONCLUSION: Intrajejunal feeding and gastric decompression via a multi-lumen tube provided effective conservative treatment of duodenal ileus together with gastric decompression.

Aged↗
PubMed2004

High-resolution method for regulatory control of Echinacea species in Nutraceuticals by CD-MEKC.

One problem in the international regulatory control of Echinacea, a therapeutic Nutraceutical, is recognition of caffeoyl solutes and alkamides in different products. Cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) has been applied to Echinacea spp. in combination with pattern recognition of some caffeoyl solutes. A novel metric based on relative migration time (RMT) data has been developed in CE to address the problem of variable reported migration time. The CD-MEKC method of Gotti's group using hydroxypropyl-beta-cyclodexrin (HP-beta-CD; 100 mM) with sodium dodecyl sulphate (SDS; 110 mM), in a triacid background electrolyte (10 mM, pH 8) under 19 kV was adapted to identify two key hydrophilic solutes: chlorogenic acid and cichoric acid present in all commercial products. Two internal markers were taken as reference points to calculate the RMT of any target peak: RMT=t(m (target))/t(m (marker)). The RMT method was robust to temperature change from 20 to 40 degrees C, but sensitive to pH. The lateral shift and reproducibility of the target peak t(m (target)) were significantly reduced by this novel transformation. In the worst cases migration time variability ranged up to 12% (n=6); the RMT algorithm reduced this to less than 1%. In general, the RMT transformation reduced the variability of migration time data by a factor of 2-5. For systematic comparison of electrophoretic profiles for test sample and standard, a new pattern recognition algorithm permits sequential peak-by-peak comparison using specified segments of the electropherograms for comparison of test and Echinacea purpurea (root product) as a standard. This algorithm was capable of rapidly characterising the similarity of target peaks in a test sample relative to those in the reference standard. Combination of the RMT algorithm and pattern recognition in CE is expected to offer a robust approach to international regulatory characterisation and control of Nutraceuticals.

Chromatography, Micellar Electrokinetic Capillary↗
PubMed2004

Nongenetic pathologic developments of brain-wave patterns in monozygotic twins discordant and concordant for schizophrenia.

Evidence from previous studies has suggested that the inter-individual differences in human brain-wave patterns (EEG) are predominantly determined by genetic factors. In particular, the within-pair EEG concordance of monozygotic (mz) twins was found to be typically as high as r = 0.81 across channels and frequency bands, thus being comparable to that between repeated assessments on the same individual with typically r = 0.83. Yet our investigations into mz twins discordant and concordant for schizophrenia yielded a significantly reduced within-pair EEG concordance for both, the pairs discordant for schizophrenia and the pairs concordant for schizophrenia (with concordance for schizophrenia assessed through a syndrome-oriented approach). A multivariate discriminant function of EEG parameters distinguished in a reproducible way between affected and unaffected subjects at an overall performance of >75% correctly classified subjects, while the severity of illness, as derived from EEG-differences between affected and unaffected subjects, was closely related to the severity of illness as provided by psychopathology syndrome scores. Consequently, EEG anomalies associated with schizophrenia and manifested differently in the mz co-twins concordant for schizophrenia are likely the effect of nongenetic, pathologic processes that evolved independently in the co-twins' genetically identical brains once the illness began to progress. The existence of such nongenetic processes would suggest a modification of the standard phenotype-to-genotype search strategies of molecular-genetic studies that aim to link the schizophrenia phenotype to genetic vulnerability factors.

Adult↗
PubMed2002

Simultaneously presenting head and neck and lung cancer: a diagnostic and treatment dilemma.

OBJECTIVES/HYPOTHESIS: Synchronous tumors are defined as malignancies presenting within 6 months of the index tumors. A significant subset of patients present at initial evaluation with malignant tumors of both the head and neck (head and neck squamous cell carcinoma) and the lung, which are termed simultaneous primaries. The management and treatment outcomes in this cohort of patients have not been clearly defined and are the subject of the present review. STUDY DESIGN: Retrospective chart review of previously untreated patients. METHODS: From January 1974 to December 1997, a total of 2964 patients were treated for mucosal squamous cell carcinoma of the head and neck. Forty-two patients fulfilled the criteria for synchronous head and neck and lung malignancy. Of these, 27 patients had simultaneous tumors of the head and neck and the lung. This cohort of patients (n = 27) was stratified into three treatment groups. Patients in group A (n = 10) had resectable head and neck and lung primaries treated with curative intent. Group B (n = 8) was composed of patients who could have been treated with curative intent but declined and were given only palliative therapy. Patients in group C (n = 9) were candidates for only palliative treatment. RESULTS: The estimated 5-year disease-specific survival in group A was 47%, whereas patients in group B had a 5-year disease-specific survival of only 13% (P =.05). There were no survivors beyond 1 year in group C. The presence of mediastinal adenopathy in patients in group A portended poor clinical outcome. There was an estimated 5-year disease-specific survival of 51% in patients with no preoperative evidence of mediastinal adenopathy (n = 7), whereas 67% of patients with radiological evidence of mediastinal adenopathy died (two of three patients). CONCLUSION: The presence of simultaneous head and neck squamous cell carcinoma and pulmonary malignancies should not be a deterrent to aggressive surgical therapy because a potentially satisfactory outcome can be expected in these patients.

Aged↗
PubMed2001

The effect of vancomycin and third-generation cephalosporins on prevalence of vancomycin-resistant enterococci in 126 U.S. adult intensive care units.

BACKGROUND: Patient-specific risk factors for acquisition of vancomycin-resistant enterococci (VRE) among hospitalized patients are becoming well defined. However, few studies have reported data on the institutional risk factors, including rates of antimicrobial use, that predict rates of VRE. Identifying modifiable institutional factors can advance quality-improvement efforts to minimize hospital-acquired infections with VRE. OBJECTIVE: To determine the independent importance of any association between antimicrobial use and risk factors for nosocomial infection on rates of VRE in intensive care units (ICUs). DESIGN: Prospective ecologic study. SETTING: 126 adult ICUs from 60 U.S. hospitals from January 1996 through July 1999. PATIENTS: All patients admitted to participating ICUs. MEASUREMENTS: Monthly use of antimicrobial agents (defined daily doses per 1000 patient-days), nosocomial infection rates, and susceptibilities of all tested enterococci isolated from clinical cultures. RESULTS: Prevalence of VRE (median, 10%; range, 0% to 59%) varied by type of ICU and by teaching status and size of the hospital. Prevalence of VRE was strongly associated with VRE prevalence among inpatient non-ICU areas and outpatient areas in the hospital, ventilator-days per 1000 patient-days, and rate of parenteral vancomycin use. In a weighted linear regression model controlling for type of ICU and rates of VRE among non-ICU inpatient areas, rates of vancomycin use (P < 0.001) and third-generation cephalosporin use (P = 0.02) were independently associated with VRE prevalence. CONCLUSIONS: Higher rates of vancomycin or third-generation cephalosporin use were associated with increased prevalence of VRE, independent of other ICU characteristics and the endemic VRE prevalence elsewhere in the hospital. Decreasing the use rates of these antimicrobial agents could reduce rates of VRE in ICUs.

Anti-Bacterial Agents↗
PubMed2001

Categorizing sex and identity from the biological motion of faces.

Head and facial movements can provide valuable cues to identity in addition to their primary roles in communicating speech and expression [1-8]. Here we report experiments in which we have used recent motion capture and animation techniques to animate an average head [9]. These techniques have allowed the isolation of motion from other cues and have enabled us to separate rigid translations and rotations of the head from nonrigid facial motion. In particular, we tested whether human observers can judge sex and identity on the basis of this information. Results show that people can discriminate both between individuals and between males and females from motion-based information alone. Rigid head movements appear particularly useful for categorization on the basis of identity, while nonrigid motion is more useful for categorization on the basis of sex. Accuracy for both sex and identity judgements is reduced when faces are presented upside down, and this finding shows that performance is not based on low-level motion cues alone and suggests that the information is represented in an object-based motion-encoding system specialized for upright faces. Playing animations backward also reduced performance for sex judgements and emphasized the importance of direction specificity in admitting access to stored representations of characteristic male and female movements.

Communication↗
PubMed2001

Sleep deprivation as a predictor of response to light therapy in major depression.

BACKGROUND: While the majority of depressed patients benefit from total sleep deprivation (TSD), light therapy is regarded as a first-line treatment only for seasonal affective disorder (SAD). The results of light therapy in nonseasonal major depressive disorder have been non-conclusive. We examined the correlation of TSD response and light therapy response in major depressed patients. METHODS: 40 inpatients with major depressive disorder (seven with seasonal pattern, 33 without seasonal pattern) were deprived of a night's sleep. The TSD responders, as well as the TSD nonresponders, were randomly assigned to receive adjunct light therapy either with bright white light (2500 lux) or dim red light (50 lux) during 2 weeks beginning on the third day after TSD. RESULTS: The 20 TSD responders improved significantly better under the light therapy than the 20 TSD nonresponders (according to the Hamilton Depression Rating Scale and the self-rating depression scale Bf-S; v. Zerssen). LIMITATIONS: No significant difference could be found between the two light intensities. Since the patients were additionally treated with medication an interaction with the two adjunctive therapies cannot be excluded. CONCLUSION: Our results indicate that a positive TSD response in major depressed patients can be predicative of beneficial outcome of subsequent light therapy.

Adult↗
PubMed2001

Growth hormone and insulin-like growth factor-I: effects on the growth of glioma cell lines.

Growth hormone (GH) and insulin-like growth factor-I (IGF-I) are known to be mitogens for many types of neoplasms. To investigate their role in tumors of glial origin, in vitro and in vivo experiments were performed with a panel of immortalized glioma cell lines (D54, SNB-19, U87, U251 and U373). Initial analysis for mRNA expression demonstrated the following: GH receptor (5/5 cell lines positive), IGF-I (0/5), IGF-II (0/5), IGF-I receptor (5/5), IGF-II receptor (2/5). Thus, each cell line expressed the necessary receptors to respond to GH and the IGFs but there was no autocrine IGF production by the tumors themselves. IGF-I stimulated mitogenesis as measured by [(3)H]thymidine uptake experiments in U251 and U373 cells. However, when these two IGF-responsive cell lines were xenografted into mice, tumor development and growth rates were not significantly different in GH-deficient animals (despite having IGF-I serum concentrations only 31% of normal). Because our studies were performed in immunocompromised animals, GH or IGF effects on immune surveillance, known to be important from some syngeneic glioma models, would not be likely to contribute to our findings. Nevertheless, these studies are important because they demonstrate that the growth of glioma cell lines in an in vivo environment can remain robust in a GH/IGF-I-deficient setting, even if in vitro experiments indicate that IGF-I is mitogenic.

Animals↗
PubMed2001

[Sleep deprivation as a predictor of response to light therapy in major depression].

Light therapy (LT) is regarded as the treatment of choice for seasonal affective disorder (SAD). In nonseasonal depression the results of light therapy are nonconclusive. Sleep deprivation (SD), however, is effective in 50-60% of the patients with major depression. The predictive value of Total Sleep Deprivation (TSD) for the treatment outcome of antidepressiva has been already examined. Purpose of the present study was to test whether light therapy is more beneficial in TSD responders than in TSD nonresponders. 40 inpatients with major depressive disorder completed one night of TSD. Twenty TSD responders and 20 TSD nonresponders were randomly assigned to 14 days of bright light therapy (2500 lux, 7-9 a.m.) or 14 days of dim light therapy (red light 50 lux, 7-9 a.m.). Manova with repeated measurements revealed a significant difference in the course of depression over the time between TSD responders and nonresponders, but no significant difference between bright and dim light. Questions of placebo effect, of SAD and of personality variables as predictors of response to SD and LT are being discussed.

Adult↗
PubMed2001

Neoadjuvant therapy with interleukin-12-loaded polylactic acid microspheres reduces local recurrence and distant metastases.

BACKGROUND: We previously demonstrated that the intratumoral injection of biodegradable polylactic acid microspheres that were loaded with interleukin (IL)-12 can induce a systemic antitumor immunity. We sought to investigate the clinical potential as neoadjuvant therapy. METHODS: Mice were inoculated with 5 x 10(7) Line-1 cells subcutaneously. Six days later, a single intratumoral injection of IL-12- or BSA-loaded microspheres were given; 14 days later, autopsy was performed to document metastases. Mice were inoculated with 5 x 10(7) Line-1 cells and 10 days later either treated with IL-12- or BSA-loaded microspheres or resected. Treated tumors were resected 6 days after treatment. Mice were observed 45 days for local recurrence before autopsy. RESULTS: Intratumoral injection of IL-12 microspheres resulted in significant suppression of tumor growth compared with controls (599 +/- 255 mm(3) vs 1591 +/- 372 mm(3); P =.001) and pulmonary metastases (0.4 vs 3.8 nodules per mouse; P =.003). Given before the operation, IL-12-loaded microspheres both decreased the local recurrence rate (100% to 40%) and pulmonary metastases (5.2 vs 0.6 nodules per mouse; P =.06). Earlier resection did not improve local recurrence or distant metastases. CONCLUSIONS: Intratumoral injection of IL-12-loaded polylactic acid microspheres promotes the development of systemic antitumor immunity that can eradicate micrometastases. As a neoadjuvant therapy, this can result in decreased local and distant recurrence.

Adenocarcinoma↗
PubMed2001

Students' expectations of learning key skills and knowledge.

Students' expectations of the key skills and knowledge they acquire and how their perceptions of these change during the four year period of their speech and language therapy (SLT) degree programme are explored. This is important because students are central to the teaching and learning process so their expectations of learning have to be taken into account in order to best help them to achieve the required learning outcomes. Over 100 De Montfort University (DMU) SLT under-graduate students from the four years were surveyed by questionnaire. The research findings are discussed to examine the significance of differences between and within year cohorts. The outcomes of this research will provide a basis for recommendations for DMU and other universities' SLT programmes, and for the improvement of student learning guidance.

Health Knowledge, Attitudes, Practice↗
PubMed2001

Antitumor activity of the growth hormone receptor antagonist pegvisomant against human meningiomas in nude mice.

OBJECT: The authors have previously demonstrated that modulation of the growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis can significantly affect meningioma growth in vitro. These studies were performed to evaluate the efficacy of GH receptor blockade in vivo. METHODS: Primary cultures from 15 meningioma tumors obtained in humans were xenografted into athymic mice. Approximately 1.5 million cells from each of the 15 tumors were implanted into the flanks of two female mice, one pair for each tumor. One animal from each of the 15 pairs was then treated with the GH receptor antagonist pegvisomant and the other with vehicle alone for 8 weeks. The tumor volume was measured using digital calipers three times per week. The mean tumor volume at the initiation of injections was 284 +/- 18.8 mm3 in the vehicle group and 291.1 +/- 20 mm3 in the pegvisomant group. After 8 weeks of treatment, the mean volume of tumors in the pegvisomant group was 198.3 +/- 18.9 mm3 compared with 350.1 +/- 23.5 mm3 for the vehicle group (p < 0.001). The serum IGF-I concentration in the vehicle group was 319 +/- 12.9 microg/L compared with 257 +/- 9.7 in the pegvisomant group (p < 0.02). A small but significant decrease was observed in circulating IGF binding protein (IGFBP)-3 levels, whereas slight increases occurred with respect to serum IGFBP-1 and IGFBP-4 levels. In the placebo group the tumor weight was 0.092 +/- 0.01 g compared with 0.057 +/- 0.01 g in the pegvisomant group (p < 0.02). The IGF-I and IGF-II concentrations were measured in the tumors by using a tissue extraction method. These human-specific immunoassays demonstrated that there was no autocrine production of IGF-I in any of the tumors, either in the pegvisomant or vehicle group. The IGF-I levels were highly variable (0-38.2 ng/g tissue) and did not differ significantly between treatment groups. CONCLUSIONS: In an in vivo tumor model, downregulation of the GH/IGF-I axis significantly reduces meningioma growth and, in some instances, causes tumor regression. Because the concentrations of IGF-II in tumor did not vary with pegvisomant treatment and there was no autocrine IGF-I production by the tumors, the mechanism of the antitumor effect is most likely a decrease of IGF-I in the circulation and/or surrounding host tissues. Because the authors have previously demonstrated that the GH receptor is ubiquitously expressed in meningiomas, direct blockade of the GH receptor on the tumors may also be contributing to inhibitory actions.

Adult↗
PubMed2001

Susceptibility to maladaptive responses to stress in basic military training based on variants of temperament and character.

The purpose of this study was to compare the relationship of Temperament and Character Inventory (TCI) scores of three groups of U.S. Air Force basic trainees. The following groups were used: those who were psychiatrically hospitalized, a control group, and a group identified as being at risk for early separation from basic training because of psychological reasons. The instrument used was the TCI. The data were analyzed with analysis of variance, Tukey post hoc comparisons, and stepwise backward discriminant analysis. The controls were found to have healthier temperament and character profiles than both the at-risk (p < 0.01) and hospitalized (p < 0.01) groups. No difference was found between the at-risk and hospitalized groups on TCI scores. The TCI was found to successfully predict 82% of controls, 25% of at-risk, and 64% of hospitalized recruits. Risk factors for maladaptive responses to stress and possible ways of primary prevention are presented.

Adolescent↗
PubMed2000

Mortality among males with hemophilia: relations with source of medical care. The Hemophilia Surveillance System Project Investigators.

Although persons with hemophilia are known to be at increased risk of death, no studies have examined the source of medical care and other personal characteristics for associations with mortality. To determine death rates and to identify causes of death and predictors of mortality, we studied a cohort comprised of all hemophilic males identified by a six-state surveillance system. Data were obtained by medical record review of contacts with physicians, hemophilia treatment centers (HTCs), and other sources of care during 1993-1995 and from death certificates. Factors examined included age, race, state of residence, health insurance type, medical care source, hemophilia type/severity, presence of inhibitor, liver disease, HIV infection, and AIDS. A total of 2950 subjects were followed for an average of 2.6 years. Their median age was 22 years; 73% were white, 79% had hemophilia A, 42% had severe disease, and 67% had visited an HTC. During 7575 person years (PYs) of observation, 236 persons died-an age-adjusted mortality rate of 40.4 deaths/1000 PYs; 65% of deaths were HIV related. In addition to age, factors independently associated with increased risk of death (relative risk, P value) were the following: AIDS (33.5, <.001); HIV infection (4.7, <.001); liver disease (2.4, <.001); and Medicare/Medicaid insurance (1.4,. 01). Those persons who had received care in an HTC had a significantly decreased risk of death (0.6,.002). Although HIV infection and the presence of severe liver disease remain strong predictors of mortality, survival is significantly greater among hemophilics who receive medical care in HTCs. (Blood. 2000;96:437-442)

Acquired Immunodeficiency Syndrome↗
PubMed2000

Exaggerating temporal differences enhances recognition of individuals from point light displays.

Humans are very good at perceiving each other's movements. In this article, we investigate the role of time-based information in the recognition of individuals from point light biological motion sequences. We report an experiment in which we used an exaggeration technique that changes temporal properties while keeping spatial information constant; differences in the durations of motion segments are exaggerated relative to average values. Participants first learned to recognize six individuals on the basis of a simple, unexaggerated arm movement. Subsequently, they recognized positively exaggerated versions of those movements better than the originals. Absolute duration did not appear to be the critical cue. The results show that time-based cues are used for the recognition of movements and that exaggerating temporal differences improves performance. The results suggest that exaggeration may reflect general principles of how diagnostic information is encoded for recognition in different domains.

Adult↗
PubMed1999

Electrophysiological correlates of direct versus indirect semantic priming in normal volunteers.

The N400 component of event related potentials (ERP) was studied in 27 right-handed healthy subjects in a speeded lexical decision task. The semantic distance between primes (always words) and targets (50% words, 50% non-words) was systematically varied. Prime-target relations included directly related words (hen-egg), indirectly related words (lemon-sweet), and non-related words (sofa-wing). ERPs were recorded from 20 scalp electrodes positioned according to the international 10-20 system. The N400 reflected semantic distance with the most negative and latest N400 peak in the non-related condition, the least negative and earliest N400 peak in the direct condition and the peak in the indirect condition in-between. Hence, N400 priming effect in the indirect condition was obtained in the absence of strong sentential constraints and even though the mediating word was physically not present.

Adult↗
PubMed1999

Genetic influence on auditory information processing in schizophrenia: P300 in monozygotic twins.

BACKGROUND: It is widely accepted that schizophrenia is to some extent genetically determined. Abnormalities of the P300 component are one of the most robust biological findings in schizophrenia. They outlast clinical impairment and are present also in relatives of schizophrenic patients. In the present study on schizophrenic twins, the heritability of auditory P300 abnormalities and the influence of task difficulty on heritability was examined. METHODS: Twenty-two monozygotic twin pairs were included into this study (eight pairs discordant, five pairs concordant for schizophrenia or schizoaffective psychosis according to ICD-10 criteria, and nine control pairs). Two different versions of the auditory oddball paradigm were used to control for deficient stimulus perception. RESULTS: Compared to healthy controls, P300 amplitudes were significantly smaller in affected twins as well as in the non-affected co-twins of the discordant pairs. CONCLUSIONS: Our results suggest that P300 amplitude reduction is a genetically transmitted vulnerability marker for schizophrenia. Because the findings were independent of the difficulty of the task and could be demonstrated even when pitch disparity was adjusted to the subjects' ability to discriminate tones, the findings can not be related to the genetic influence on higher information processing.

Adult↗