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2.
Hernia ; 2024 Mar 21.
Article in English | MEDLINE | ID: mdl-38512506

ABSTRACT

PURPOSE: International guidelines exist for surgical treatment of either ventral or inguinal hernias repair (VHR; IHR). However, approach for managing both of them remains unestablished and is further complicated by newly developed surgical techniques and modalities (namely, robotic). This highlights the need for a tailored, algorithmic strategy to streamline surgical management. METHODS: An algorithm was developed by the directors of the NYU Langone Abdominal Core Health program of which four treatment groups were described: Group 1: open VHR and either laparoscopic or robotic IHR; Group 2: robotic transabdominal pre-peritoneal (TAPP) approach for both VHR and IHR; Group 3: robotic retro-muscular VHR and IHR; and Group 4: open repair for both. Demographics, comorbidities, operative characteristics, and surgical outcomes from November 2021 to July 2023 were retrospectively compared. RESULTS: Ninety-two patients were included with a median age of 64 years, 90% (n = 83) were white, 85% (n = 78) were male, median BMI was 27 kg/m2, and 73% (n = 67) were ASA class II. Distribution of groups was: 48% (n = 44) in 1A, 8% (n = 7) in 1B, 8% (n = 7) in 2A, 3% (n = 3) in 2B, 23% (n = 21) in 3A, 8% (n = 7) in 3B, and 3% (n = 3) in 4. Ventral hernia size, OR time, and postoperative length of stay varied across groups. Postoperative outcomes at 30 days including emergency consults, readmissions, and complications, showed no differences across groups. CONCLUSION: Access without guidance to new minimally invasive surgical approaches can be a challenge for the general surgeon. We propose an algorithm for decision-making based on our experience of incorporating robotic surgery, when available, for repair of concomitant VHR and IHR with consistent favorable outcomes within a small sample of patients.

3.
Neuropsychology ; 38(1): 58-68, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37870806

ABSTRACT

OBJECTIVE: Much of our knowledge concerning the neural basis of human memory derives from lab-based verbal recall tasks. Outside of the lab, clinicians use validated and normed neuropsychological tests to assess patients' memory function and to evaluate clinical interventions. Here we sought to establish the clinical validity of examining memory through multitrial free recall of semantically organized and unrelated word lists. METHOD: We compare memory performance in multitrial free recall tasks with the Rey Auditory Verbal Learning Test and the California Verbal Learning Test, two common neuropsychological tests aimed at evaluating memory function in clinical settings. We compare predictive validity between the tasks by evaluating deficits in a patient sample and examining age-related declines in memory. We additionally compare test-retest reliability, establish convergent validity, and show the emergence of common recall dynamics between the tasks. RESULTS: We demonstrate that both laboratory free recall tasks have better predictive validity and test-retest reliability than the established neuropsychological tests. We further show that all tasks have good convergent validity and reveal core memory processes, including temporal and semantic organization. However, we also demonstrate the benefits of repeated trials for evaluating the dynamics of memory search and their neuropsychological sequelae. CONCLUSIONS: These results provide evidence for the clinical validity of lab-based multitrial free recall tasks and highlight their psychometric benefits over neuropsychological measures. Based on these results, we discuss the need to bridge the gap between clinical understanding of putative mechanisms underlying memory disorders and neuroscientific findings obtained using lab-based free recall tasks. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Subject(s)
Mental Recall , Verbal Learning , Humans , Reproducibility of Results , Memory , Neuropsychological Tests
4.
Hernia ; 27(3): 645-656, 2023 06.
Article in English | MEDLINE | ID: mdl-36977947

ABSTRACT

INTRODUCTION: Robotic abdominal wall reconstruction (RAWR) is one of the most significant advances in the management of complex abdominal wall hernias. The objective of this study was to evaluate long term outcomes in a cohort of patients that underwent complex RAWR in a single center. METHODS: This was a longitudinal retrospective review of a cohort of 56 patients who underwent complex RAWR at least 24 months prior by a single surgeon at a tertiary care institution. All patients underwent bilateral retro-rectus release (rRRR) with or without robotic transversus abdominis release (rTAR). Data collected include demographics, hernia details, operative and technical details. The prospective analysis included a post-procedure visit of at least 24 months from the index procedure with a physical examination and quality of life survey using the Carolinas Comfort Scale (CCS). Patients with reported symptoms concerning for hernia recurrence underwent radiographic imaging. Descriptive statistics (mean ± standard deviation or median) were calculated for continuous variables. Chi-square or Fisher's exact test as deemed appropriate for categorical variables, and analysis of variance or the Kruskal-Wallis test for continuous data, were performed among the separate operative groups. A total score for the CCS was calculated and analyzed in accordance with the user guidelines. RESULTS: One-hundred and-forty patients met the inclusion criteria. Fifty-six patients consented to participate in the study. Mean age was 60.2 years. Mean BMI was 34.0. Ninety percent of patients had at least one comorbidity and 52% of patients were scored ASA 3 or higher. Fifty-nine percent were initial incisional hernias, 19.6% were recurrent incisional hernias and 8.9% were recurrent ventral hernias. The mean defect width was 9 cm for rTAR and 5 cm for rRRR. The mean implanted mesh size was 945.0 cm2 for rTAR and 362.5 cm2 for rRRR. The mean length of follow-up was 28.1 months. Fifty-seven percent of patients underwent post-op imaging at an average follow-up of 23.5 months. Recurrence rate was 3.6% for all groups. There were no recurrences in patients that underwent solely bilateral rRRR. Two patients (7.7%) that underwent rTAR procedures were found with recurrence. Average time to recurrence was 23 months. Quality of life survey demonstrated an overall CCS score of 6.63 ± 13.95 at 24 months with 12 (21.4%) patients reporting mesh sensation, 20 (35.7%) reporting pain, and 13 (23.2%) reporting movement limitation. CONCLUSION: Our study contributes to the paucity of literature describing long term outcomes of RAWR. Robotic techniques offer durable repairs with acceptable quality of life metrics.


Subject(s)
Abdominal Wall , Hernia, Ventral , Incisional Hernia , Robotic Surgical Procedures , Surgeons , Humans , Middle Aged , Incisional Hernia/surgery , Abdominal Wall/surgery , Robotic Surgical Procedures/adverse effects , Robotic Surgical Procedures/methods , Quality of Life , Herniorrhaphy/adverse effects , Herniorrhaphy/methods , Hernia, Ventral/surgery , Abdominal Muscles/surgery , Retrospective Studies , Surgical Mesh
5.
Biomed Res Int ; 2022: 5004282, 2022.
Article in English | MEDLINE | ID: mdl-35722456

ABSTRACT

Background: Burn injuries in children are a major physical and psychological trauma, often a severe condition with long-term consequences. Current methods of assessing the extent of burn injuries on admission are inaccurate. Circulating cell-free DNA (cfDNA) is a potential marker of tissue damage that may be useful in burn care. Objective: To explore the use of cfDNA admission levels as a prognostic marker of pediatric burn severity and outcome. Methods: cfDNA levels of 38 pediatric burn patients (otherwise healthy) and 12 matched pediatric controls (minor elective surgery patients) admitted to our center were quantified by a direct fluorometric assay. Results: We found significantly higher admission cfDNA levels in the patient group (median 724 ng/ml, range 44-4405), compared to the control group (median 423 ng/ml, range 206-970, Mann-Whitney, P = 0.03) and a significant difference between cfDNA levels of partial-thickness burns (median 590 ng/ml, range 44-2909) and full-thickness burns (median 2394 ng/ml, range 528-4405, Mann-Whitney, P = 0.01). We also found significant correlations between cfDNA levels and hospitalization duration (Spearman, R = 0.42, P < 0.01) and undergoing surgical procedures (Spearman, R = 0.40, P < 0.01). PICU admission did not correlate to cfDNA levels (Spearman, R = 0.14, P = NS). Discussion. Admission cfDNA levels may be a valuable objective tool for assessing the severity of pediatric burn injuries on admission, including correlations with the length of hospitalization and surgical burden. Conclusion: Admission cfDNA levels may be a promising novel pediatric burn assessment method. Further investigation of cfDNA levels in healthy children standardized to age and larger cohorts are needed to establish cfDNA as a valuable prognostic factor for pediatric burn injury.


Subject(s)
Burns , Cell-Free Nucleic Acids , Burns/diagnosis , Child , Hospitalization , Humans , Length of Stay , Prognosis , Retrospective Studies
6.
Mol Autism ; 13(1): 17, 2022 04 08.
Article in English | MEDLINE | ID: mdl-35395866

ABSTRACT

BACKGROUND: Phelan-McDermid syndrome (PMS) is caused by haploinsufficiency of the SHANK3 gene and is characterized by global developmental delays and autism spectrum disorder (ASD). Based on several converging lines of preclinical and clinical evidence supporting the use of insulin-like growth factor-1 (IGF-1) in PMS, this study aims to follow-up a previous pilot study with IGF-1 to further evaluate this novel therapeutic for core symptoms of ASD in children with PMS. METHODS: Ten children aged 5-9 with PMS were enrolled. Participants were randomized to receive IGF-1 or placebo (saline) using a 12-week, double-blind, crossover design. Efficacy was assessed using the primary outcome of the Aberrant Behavior Checklist-Social Withdrawal (ABC-SW) subscale as well as secondary outcome measures reflecting core symptoms of ASD. To increase power and sample size, we jointly analyzed the effect of IGF-1 reported here together with results from our previous controlled trail of IGF-1 in children with PMS (combined N = 19). RESULTS: Results on the ABC-SW did not reach statistical significance, however significant improvements in sensory reactivity symptoms were observed. In our pooled analyses, IGF-1 treatment also led to significant improvements in repetitive behaviors and hyperactivity. There were no other statistically significant effects seen across other clinical outcome measures. IGF-1 was well tolerated and there were no serious adverse events. LIMITATIONS: The small sample size and expectancy bias due to relying on parent reported outcome measures may contribute to limitations in interpreting results. CONCLUSION: IGF-1 is efficacious in improving sensory reactivity symptoms, repetitive behaviors, and hyperactivity  in children with PMS. Trial registration NCT01525901.


Subject(s)
Chromosome Disorders , Insulin-Like Growth Factor I , Child , Chromosome Deletion , Chromosome Disorders/drug therapy , Chromosome Disorders/genetics , Chromosomes, Human, Pair 22 , Humans , Insulin-Like Growth Factor I/therapeutic use , Pilot Projects
7.
Mol Autism ; 13(1): 6, 2022 01 29.
Article in English | MEDLINE | ID: mdl-35093163

ABSTRACT

BACKGROUND: Phelan-McDermid syndrome (PMS) is caused by 22q13 deletions including SHANK3 or pathogenic sequence variants in SHANK3 and is among the more common rare genetic findings in autism spectrum disorder (ASD). SHANK3 is critical for synaptic function, and preclinical and clinical studies suggest that insulin-like growth factor-1 (IGF-1) can reverse a range of deficits in PMS. IGF-1 release is stimulated by growth hormone secretion from the anterior pituitary gland, and this study sought to assess the feasibility of increasing IGF-1 levels through recombinant human growth hormone (rhGH) treatment, in addition to establishing safety and exploring efficacy of rhGH in children with PMS. METHODS: rhGH was administered once daily for 12 weeks to six children with PMS using an open-label design. IGF-1 levels, safety, and efficacy assessments were measured every 4 weeks throughout the study. RESULTS: rhGH administration increased levels of IGF-1 by at least 2 standard deviations and was well tolerated without serious adverse events. rhGH treatment was also associated with clinical improvement in social withdrawal, hyperactivity, and sensory symptoms. LIMITATIONS: Results should be interpreted with caution given the small sample size and lack of a placebo control. CONCLUSIONS: Overall, findings are promising and indicate the need for larger studies with rhGH in PMS. Trial registration NCT04003207. Registered July 1, 2019, https://clinicaltrials.gov/ct2/show/NCT04003207 .


Subject(s)
Autism Spectrum Disorder , Human Growth Hormone , Autism Spectrum Disorder/genetics , Child , Chromosome Deletion , Chromosome Disorders , Chromosomes, Human, Pair 22 , Growth Hormone , Human Growth Hormone/therapeutic use , Humans , Insulin-Like Growth Factor I
8.
Mol Autism ; 12(1): 62, 2021 09 30.
Article in English | MEDLINE | ID: mdl-34593045

ABSTRACT

BACKGROUND: Phelan-McDermid syndrome (PMS) is a rare neurodevelopmental disorder caused by haploinsufficiency of the SHANK3 gene and characterized by global developmental delays, deficits in speech and motor function, and autism spectrum disorder (ASD). Monogenic causes of ASD such as PMS are well suited to investigations with novel therapeutics, as interventions can be targeted based on established genetic etiology. While preclinical studies have demonstrated that the neuropeptide oxytocin can reverse electrophysiological, attentional, and social recognition memory deficits in Shank3-deficient rats, there have been no trials in individuals with PMS. The purpose of this study is to assess the efficacy and safety of intranasal oxytocin as a treatment for the core symptoms of ASD in a cohort of children with PMS. METHODS: Eighteen children aged 5-17 with PMS were enrolled. Participants were randomized to receive intranasal oxytocin or placebo (intranasal saline) and underwent treatment during a 12-week double-blind, parallel group phase, followed by a 12-week open-label extension phase during which all participants received oxytocin. Efficacy was assessed using the primary outcome of the Aberrant Behavior Checklist-Social Withdrawal (ABC-SW) subscale as well as a number of secondary outcome measures related to the core symptoms of ASD. Safety was monitored throughout the study period. RESULTS: There was no statistically significant improvement with oxytocin as compared to placebo on the ABC-SW (Mann-Whitney U = 50, p = 0.055), or on any secondary outcome measures, during either the double-blind or open-label phases. Oxytocin was generally well tolerated, and there were no serious adverse events. LIMITATIONS: The small sample size, potential challenges with drug administration, and expectancy bias due to relying on parent reported outcome measures may all contribute to limitations in interpreting results. CONCLUSION: Our results suggest that intranasal oxytocin is not efficacious in improving the core symptoms of ASD in children with PMS. Trial registration NCT02710084.


Subject(s)
Autism Spectrum Disorder , Chromosome Disorders , Adolescent , Autism Spectrum Disorder/genetics , Child , Child, Preschool , Chromosome Deletion , Chromosome Disorders/diagnosis , Chromosome Disorders/drug therapy , Chromosomes, Human, Pair 22 , Humans , Oxytocin/therapeutic use
9.
J Biomech Eng ; 126(4): 410-9, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15543858

ABSTRACT

Soluble surfactant and airway surface liquid transport are examined using a mathematical model of Marangoni flows which accounts for airway branching and for cyclic airway stretching. Both radial and longitudinal wall strains are considered. The model allows for variation of the amplitude and frequency of the motion, as may occur under a variety of ventilatory situations occurring during surfactant replacement therapy. The soluble surfactant dynamics of the thin fluid film are modeled by linear sorption. The delivery of surfactants into the lung is handled by setting the proximal boundary condition to a higher concentration compared to the distal boundary condition. Starting with a steady-state, nonuniform, surfactant distribution, we find that transport of surfactant into the lung is enhanced for increasing strain amplitudes. However, for fixed amplitude, increasing frequency has a smaller effect. At small strain amplitudes, increasing frequency enhances transport, but at large strain amplitudes, increasing cycling frequency has the opposite effect.


Subject(s)
Lung/chemistry , Lung/physiology , Models, Biological , Pulmonary Surfactants/chemistry , Pulmonary Surfactants/metabolism , Respiratory Mechanics/physiology , Rheology/methods , Animals , Biological Transport , Computer Simulation , Elasticity , Humans , Lubrication , Models, Chemical , Movement/physiology , Mucous Membrane/chemistry , Mucous Membrane/physiology , Periodicity , Pressure , Pulsatile Flow/physiology , Stress, Mechanical
10.
Ophthalmol Clin North Am ; 15(1): 61-8, 2002 Mar.
Article in English | MEDLINE | ID: mdl-12064082

ABSTRACT

The optic neuropathy of glaucoma appears to be multifactorial in etiology. Both mechanical and vasogenic theories remain viable explanations for the observed nerve damage and the destructive effect of trophic withdrawal could be espoused by either theory. Each theory feeds into the final common pathway of cell death; even the immune system may kill cells in glaucoma by apoptosis. This knowledge has led to the hope that glaucomatous nerve damage can be curtailed or even prevented with the use of neuroprotective agents. Indeed, there are many intriguing new therapeutic possibilities on the horizon. Until evidence from clinical trials demonstrates the effectiveness of these agents however, control of IOP will remain the mainstay of treatment for glaucoma.


Subject(s)
Glaucoma, Open-Angle/physiopathology , Optic Nerve Diseases/physiopathology , Glaucoma, Open-Angle/complications , Glaucoma, Open-Angle/drug therapy , Humans , Neuroprotective Agents/therapeutic use , Optic Nerve Diseases/drug therapy , Optic Nerve Diseases/etiology
11.
Surg Endosc ; 16(1): 215, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11961643

ABSTRACT

We present the case of a 30-year-old man who developed a small bowel obstruction from an acute midgut volvulus 8 days after undergoing a laparoscopic appendectomy. There was no evidence of congenital malrotation or midgut volvulus on the initial computed tomography (CT) scan or at laparoscopy. Subsequently, a midgut volvulus developed in the absence of congenital malrotation.


Subject(s)
Appendectomy/adverse effects , Intestinal Obstruction/etiology , Intestinal Obstruction/surgery , Laparoscopy/adverse effects , Abdominal Pain/surgery , Acute Disease , Adult , Appendectomy/methods , Cecum/pathology , Diagnostic Techniques, Surgical , Humans , Inflammation/diagnosis , Inflammation/surgery , Laparoscopy/methods , Male , Tomography, X-Ray Computed
12.
Semin Ophthalmol ; 17(3-4): 181-6, 2002.
Article in English | MEDLINE | ID: mdl-12759848

ABSTRACT

Prostaglandin analogs are powerful ocular hypotensive agents that may also be associated with a breakdown of the blood-retinal barrier and cystoid macular edema. The association is evident in pseudophakic or aphakic patients. This paper presents a case of unilateral latanoprost-associated clinical cystoid macular edema in a bilaterally pseudophakic patient; the only difference between the two eyes was the presence of a capsulotomy in the affected eye. We review the literature concerning prostaglandin analog-associated cystoid macular edema, as well as the evidence for prostaglandin analog-associated breakdown of the blood-retinal barrier. Although some evidence is suggestive of a connection between prostaglandin analogs and cystoid macular edema, many questions concerning the complex physiology of prostanoids remain. Until our understanding of these issues is more advanced, judicious use of prostaglandin analogs in patients at risk for cystoid macular edema would be prudent.


Subject(s)
Antihypertensive Agents/adverse effects , Aphakia, Postcataract/complications , Macular Edema/chemically induced , Prostaglandins F, Synthetic/adverse effects , Pseudophakia/complications , Aged , Aged, 80 and over , Blood-Retinal Barrier/drug effects , Fluorescein Angiography , Glaucoma, Open-Angle/drug therapy , Humans , Intraocular Pressure , Latanoprost , Macular Edema/diagnosis , Male , Visual Acuity
13.
Brain Cogn ; 45(3): 392-414, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11305881

ABSTRACT

To further our understanding of cognitive sex differences, we studied the relationship between menstrual phase (via serum estradiol and progesterone levels) and cognitive abilities and cognitive performance in a sample of medical students in eastern Turkey. As expected, we found no sex differences on the Cattell "Culture Fair Intelligence Test" (a figural reasoning test), with females scoring significantly higher on a Turkish version of the Finding A's Test (rapid word knowledge) and males scoring significantly higher on a paper-and-pencil mental rotation test. The women showed a slight enhancement on the Finding A's Test and a slight decrement in Cattell scores during the preovulatory phase of their cycle that (probably) coincided with a rise in estrogen. There were also small cycle-related enhancements in performance for these women on the mental rotation test that may reflect cyclical increases in estrogen and progesterone. Additional analyses showed an inverted U-shaped function in level of estradiol and the Cattell Test. Finally, for women who were tested on Day 10 of their menstrual cycle, there was a negative linear relationship between their Cattell scores and level of progesterone. Stereotypes about the cognitive abilities of males and females did not correspond to performance on the mental rotation or Finding A's Test, so the sex-typical results could not be attributed to either stereotype threat or stereotype activation. For practical purposes, hormone-related effects were generally small. Variations over the menstrual cycle do not provide evidence for a "smarter" sex, but they do further our understanding of steroidal action on human cognitive performance.


Subject(s)
Attitude , Cognition/physiology , Estrogens/physiology , Progesterone/physiology , Stereotyping , Adolescent , Adult , Environment , Female , Humans , Intelligence , Intelligence Tests , Male , Menstrual Cycle/physiology , Neuropsychological Tests , Sex Factors , Surveys and Questionnaires
14.
Drug Deliv ; 8(1): 13-7, 2001.
Article in English | MEDLINE | ID: mdl-11280438

ABSTRACT

The efficacy of a liposomal formulation for intracerebral delivery of borocaptate (BSH) to brain tumor cells has been investigated using cell culture to study BSH uptake and persistence and using tumor-bearing rats to determine BSH distribution in the brain. During a 16-hr incubation, cellular uptake of BSH solution or BSH liposomal formulation was similar. However, the cellular persistence of BSH greatly increased when BSH was present in liposome. The differences in cellular persistence for BSH solution and BSH-loaded liposomes were significant both in 12-hr and 24-hr incubation experiments (p < 0.05 and p < 0.01, respectively). For the studies involving tumor-bearing rats, BSH level in tumor tissue was significantly higher than that in normal brain tissue at 2 hr and 6 hr after intracerebral injection of BSH-loaded liposomes (p < 0.01). Our study indicated that the liposomal formulation enhanced cellular persistence of BSH in tumor cells and therefore favored the boron accumulation in the cells. With the prolonged physical retention of liposomes at the local injection site and the cellular retention of BSH enhanced by the liposomes, the intracerebral delivery of BSH using liposomal formulation may provide an effective boron delivery approach for boron neutron capture therapy of brain tumors.


Subject(s)
Borohydrides/pharmacokinetics , Boron Neutron Capture Therapy , Brain Neoplasms/metabolism , Drug Delivery Systems , Glioma/metabolism , Sulfhydryl Compounds/pharmacokinetics , Animals , Borohydrides/pharmacology , Brain/metabolism , Brain Neoplasms/drug therapy , Glioma/drug therapy , Injections , Injections, Intraventricular , Liposomes , Male , Rats , Rats, Inbred F344 , Sulfhydryl Compounds/pharmacology , Tumor Cells, Cultured/drug effects
15.
J Genet Psychol ; 161(4): 453-68, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11117101

ABSTRACT

In two experiments, the authors explored factors that might influence a person's tendency to make source-monitoring errors about autobiographical memories. In the first experiment, undergraduates retrieved a memory from childhood (a) that was known about but not remembered, (b) that was remembered, or (c) for which they were unsure of their memory's source. After writing down the memory, experimental groups listened to a guided visualization tape and answered questions about the event--interventions designed to help them focus on details of their memory. Controls also retrieved and wrote down a memory; however, instead of visualizing the memory, they were instructed to conduct a visual search task. Results indicated that guided visualization led participants to rate known memories closer to remembered events. A second experiment examined individual difference variables that might be related to this know-to-remember shift. Results indicated that extraversion, external locus of control, a memory that conveyed fear, and overall affective content predicted this rating. The applicability of these findings to the psychotherapy process is discussed.


Subject(s)
Imagery, Psychotherapy , Mental Recall , Suggestion , Adult , Analysis of Variance , Extraversion, Psychological , Fear , Female , Humans , Internal-External Control , Male , Southeastern United States
16.
J Comput Assist Tomogr ; 24(6): 884-6, 2000.
Article in English | MEDLINE | ID: mdl-11105705

ABSTRACT

We report two cases of Amyand's hernia, which is the development of acute appendicitis within an inguinal hernia. Both patients were clinically thought to have incarcerated inguinal hernias, but were correctly prospectively diagnosed as having Amyand's hernia on the basis of preoperative computed tomography (CT) examinations. Our cases again show the utility of CT of the acute abdomen and pelvis in revealing a previously unsuspected diagnosis and rapidly triaging patients to the appropriate management.


Subject(s)
Appendicitis/diagnostic imaging , Hernia, Inguinal/diagnostic imaging , Tomography, X-Ray Computed , Abdomen, Acute/diagnostic imaging , Acute Disease , Aged , Aged, 80 and over , Appendectomy , Appendicitis/surgery , Female , Hernia, Inguinal/surgery , Humans , Male , Patient Care Planning , Prospective Studies
17.
Brain Cogn ; 42(1): 128-30, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10739618
18.
Int J Soc Psychiatry ; 46(1): 34-46, 2000.
Article in English | MEDLINE | ID: mdl-14529077

ABSTRACT

Using data from a community survey of 5196 ethnic minority and 2867 white respondents, together with data on local group concentration from the 1991 Census, the hypothesis was tested that ethnic group concentration is associated with lower levels of reported psychiatric symptoms. The hypothesis was broadly confirmed, both for within- and between-group differences. However, the effect was found to be modest in size and in one group, the Pakistani sample, was reversed. The findings are inconsistent with an explanation based on selection or drift. Linguistic factors contributed to, but did not explain the effects. Evidence on victimisation and mutual support suggests that social causation, in the form of reduced exposure to direct prejudice and increased social support, is a likely cause of the effect.


Subject(s)
Ethnicity , Population Density , Surveys and Questionnaires , England , Humans , Prejudice , Residence Characteristics , Social Support , Wales
19.
J Biomech Eng ; 121(5): 505-13, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10529918

ABSTRACT

Deep sea divers suffer from decompression sickness (DCS) when their rate of ascent to the surface is too rapid. When the ambient pressure drops, inert gas bubbles may form in blood vessels and tissues. The evolution of a gas bubble in a rigid tube filled with slowly moving fluid, intended to simulate a bubble in a blood vessel, is studied by solving a coupled system of fluid-flow and gas transport equations. The governing equations for the fluid motion are solved using two techniques: an analytical method appropriate for small nondeformable spherical bubbles, and the boundary element method for deformable bubbles of arbitrary size, given an applied steady flow rate. A steady convection-diffusion equation is then solved numerically to determine the concentration of gas. The bubble volume, or equivalently the gas mass inside the bubble for a constant bubble pressure, is adjusted over time according to the mass flux at the bubble surface. Using a quasi-steady approximation, the evolution of a gas bubble in a tube is obtained. Results show that convection increases the gas pressure gradient at the bubble surface, hence increasing the rate of bubble evolution. Comparing with the result for a single gas bubble in an infinite tissue, the rate of evolution in a tube is approximately twice as fast. Surface tension is also shown to have a significant effect. These findings may have important implications for our understanding of the mechanisms of inert gas bubbles in the circulation underlying decompression sickness.


Subject(s)
Embolism, Air/physiopathology , Models, Cardiovascular , Atmospheric Pressure , Decompression Sickness/physiopathology , Humans
20.
J Appl Physiol (1985) ; 87(1): 415-27, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10409603

ABSTRACT

The capillary instability that occurs on an annular film lining a tube is studied as a model of airway closure. Small waves in the film can amplify and form a plug across the tube. This dynamical behavior is studied using theoretical models and bench-top experiments. Our model predicts the initial growth rate of the instability and its dependence on surfactant effects. In experiments, an annular film is formed by infusion of water into an initially oil-filled glass capillary tube. The thickness of the oil film varies with the infusion flow rate. The instability growth rate and closure time are measured for a range of film thicknesses. Our theory predicts that a thinner film and higher surfactant activity enhance stability; surfactant can decrease the growth rate to 25% of its surfactant-free value. In experiments, we find that surfactant can decrease the growth rate to 20% and increase the closure time by a factor of 3.8. Functional values of a critical film thickness for closure support the theory that it increases in the presence of surfactant.


Subject(s)
Lung/drug effects , Lung/physiology , Models, Biological , Pulmonary Surfactants/pharmacology , Pulmonary Surfactants/physiology , Animals , Closing Volume/drug effects , Closing Volume/physiology , Humans , Respiratory Mechanics/drug effects , Respiratory Mechanics/physiology , Surface Tension , Weightlessness Simulation/adverse effects
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