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A Park

Publications and source records attributed to A Park.

At least 55 records · Page 3Linked to original sources
PubMed2001

Special observation in the care of psychiatric inpatients: a literature review.

This paper summarizes the results of a search of electronic databases for papers on special observation (SO). Published studies to date about SO are entirely descriptive. No evaluative research appears to have taken place, leaving the procedure based on clinical pragmatism and tradition. Something between 3%-20% of admissions receive some form of SO during their stay and the rate of usage varies widely between wards. SO is used as a method of controlling and containing the most disturbed patients who are considered to be imminently at risk of harming themselves or others. Such patients tend to be younger and suffering from acute psychosis or depression. Which professional staff have the authority to initiate and terminate SO varies from place to place, as does its duration. The financial costs have been crudely assessed and are reported to be very high, perhaps up to 20% of the nursing budget for a hospital. Further variation exists on who is allowed to carry out SO. Nurses frequently make unofficial modifications to the procedure based upon their own individual judgments and assessments, and policies vary widely among hospitals. There is little agreement between authorities on what nurses should do during SO, although there is some evidence that it can, under certain circumstances, be therapeutic. However there is also evidence that nurses find SO stressful and patients dislike it.

Dangerous Behavior↗
PubMed2001

Determinants of Staphylococcus aureus nasal carriage.

Nasal carriage of Staphylococcus aureus has been identified as a risk factor for community-acquired and nosocomial infections. We screened 230 donors of diverse ethnic and socioeconomic backgrounds and identified 62 (27%) whose nasal secretions were colonized by S. aureus. In 18 donors in whom the various regions of the nasal luminal surface were separately sampled, the predominant region of S. aureus colonization was the moist squamous epithelium on the septum adjacent to the nasal ostium. Nasal fluid from carriers was defective in killing endogenous S. aureus and nasal carrier isolates of S. aureus but not a laboratory S. aureus strain. Transmission electron microscopy revealed that S. aureus isolates incubated in nasal fluid from carriers for 2 h at 37 degrees C were less damaged than those incubated in noncarrier fluid and were coated with an electron-dense layer. Compared with that from healthy donors and patients with acute rhinitis, nasal fluid from carriers contained elevated concentrations of the neutrophil-derived defensins human neutrophil peptides 1 to 3 (47- and 4-fold increases, respectively), indicative of a neutrophil-mediated inflammatory host response to S. aureus colonization. The concentration of the inducible epithelial antimicrobial peptide human beta-defensin 2 was also highly elevated compared to that in healthy donors, in whom the level was below the detection limit, or patients with acute rhinitis (sixfold increase). Thus, nasal carriage of S. aureus takes hold in nasal fluid that is permissive for colonization and induces a local inflammatory response that fails to clear the colonizing bacteria.

Body Fluids↗
PubMed2001

Protease inhibitor therapy is associated with markedly prolonged time to relapse and improved survival in AIDS patients with cytomegalovirus retinitis.

Prior to the use of highly active antiretroviral therapy (HAART), cytomegalovirus retinitis (CMV-R) in AIDS patients was characterized by multiple relapses and decreased survival. Recent data suggest that CMV-R in patients treated with HAART may remain relapse-free for long periods. We performed a study of the effects of HIV protease inhibitors (PIs) on the incidence of relapse and time to death in AIDS patients with CMV-R treated with anti-CMV therapy. Medical records of all AIDS patients with CMV-R at Parkland Memorial Health and Hospital System treated with anti-CMV agents were reviewed for date of diagnosis of CMV-R, date of CMV-R relapse, type and duration of anti-CMV therapy, and duration of PI therapy. Relapse rates in subjects treated with PIs were compared with the relapse rates in those who were not treated with PIs. The primary endpoint was the time to relapse and death as determined by Kaplan-Meier analysis. Multivariate analysis was performed by Cox proportional hazard model. One hundred and nine cases of CMV-R were identified in 75 patients. Median follow-up time was 247 days (range 31-1818 days). There were 0.54 relapses per 1000 patient days in the group treated with PIs compared with 1.83 relapses per 1000 patient days in the non-PI treatment group (relative risk [RR]=0.29, P<0.01). Time to relapse was increased in the PI treatment group compared with the non-PI treatment group (endpoint not reached vs 182 days, P<0.001, log-rank). Similarly, the time to relapse or death was increased in the PI group compared with the non-PI group (543 days vs 103 days, P<0.001, log-rank). Multivariate analysis utilizing the Cox proportional hazards model demonstrated that only PI therapy but not anti-CMV therapy was associated with decreased risk of CMV-R relapse or death. Only 3 patients with an undetectable HIV viral load and one patient with a CD4 count >120 cells/microl had a relapse. We conclude that patients with CMV-R treated with HAART containing a PI have increased time to relapse and have prolonged survival.

AIDS-Related Opportunistic Infections↗
PubMed2001

Using immersive VR as a tool for preoperative planning for minimally invasive donor nephrectomy.

For surgeons approaching minimally invasive donor nephrectomy it is important to identify variant anatomy preoperatively since this anatomy can vary significantly from patient to patient. The goal of this operation is to preserve the architecture and function of the organ so it can be transplanted and function successfully. The ability of the surgeon to navigate through an individual patient's anatomy in a virtual three-dimensional (3D) immersive environment augments understanding of anatomical relationships particular to that individual patient and facilitates conveying that information to other physicians and students. Utilizing automated 3D reconstruction of high contrast computed tomography (CT) scan files viewed in this way, surgeons reported a better preoperative understanding of the anatomical variations and encountered fewer surprises at the time of surgery.

Humans↗
PubMed2001

Laparoscopic splenectomy in patients with normal-sized spleens versus splenomegaly: does size matter?

Laparoscopic resection has become the standard means for removal of normal-sized spleens in many medical centers. The application of minimally invasive techniques in the setting of splenomegaly is less well defined and was previously considered a contraindication to the laparoscopic approach. The purpose of this prospective study of consecutive patients was to compare the outcomes of patients undergoing laparoscopic splenectomy for normal-sized spleens (150 g or less) versus those with clear evidence of splenomegaly (500 g or greater). One hundred forty-two patients met the inclusion criteria. The most common diagnosis in the normal-sized spleen group was idiopathic thrombocytopenia purpura (67 of 82, 82%). Malignant hematologic diseases (lymphoma and leukemia) were the most common diagnoses in the splenomegaly group (35 of 60, 58%). Mean operative times (127 vs 172 minutes) and estimated blood loss (123 vs 173 cm3) were lower for those patients with normal-sized spleens (P < 0.05). There were no statistical differences in conversion rates, lengths of stay, or complications between the two groups. We conclude that laparoscopic splenectomy is safe and effective in the setting of splenomegaly despite modest but statistically longer operative times and increased operative blood loss when compared with laparoscopic splenectomy for normal-sized spleens.

Adolescent↗
PubMed2001

Octylcyanoacrylate tissue adhesive as an alternative to mechanical fixation of expanded polytetrafluoroethylene prosthesis.

In minimally invasive incisional hernia repair positioning and fixation of the expanded polytetrafluoroethylene (ePTFE) mesh prosthesis on the deep surface of the abdominal wall may be facilitated using tissue adhesives. Octylcyanoacrylate (OCTYL), a new adhesive, forms a strong flexible bond with antimicrobial properties. In a rabbit model for incisional hernia we investigated characteristics of the bond created by OCTYL between ePTFE and abdominal wall musculature. We studied initial bond strength and the postoperative host response to the adhesive over a 6-week period. We compared sutured, stapled, and glued mesh prostheses and examined the tissue-prosthesis interface. The ePTFE mesh was fixed successfully to the abdominal wall with OCTYL and remained tightly attached at 6 weeks. Prostheses fixed with OCTYL and spiral tacks induced few intra-abdominal adhesions compared with sutured mesh. All prostheses were completely reperitonealized at 2 weeks. The force required to displace mesh fixed with sutures and staples was greater than mesh fixed with OCTYL. Analysis of the ePTFE/tissue interface by light and scanning electron microscopy showed host cellular migration into the interstices of the mesh with fixation by tacks and suture, whereas an inflammatory infiltrate was seen on the muscular surface with OCTYL fixation of the mesh.

Abdominal Muscles↗
PubMed2000

A pilot study of new approaches to teaching anatomy and pathology.

PURPOSE: Minimally Invasive Surgery (MIS) has impacted patient care as well as medical training. New medical education opportunities have emerged with MIS. In this pilot study we explore the role of live, interactive MIS to augment and strengthen specific segments of the undergraduate medical curriculum. METHODS: Laparoscopic cholecystectomy (LC) was selected to demonstrate upper abdominal anatomy and pathology. Second year medical students (n=100) in the course of their GI pathology classes attended live LC telesurgery-the telesurgery student group (TSG). Because of technical difficulties, a second class of medical students (n=90) was shown the tape of the MIS procedure one year later instead of the live surgery-the videotape surgery group (VSG). Background clinical information was provided by the program director and the durgeon. During the live and taped LC broadcast living anatomy was demonstrated and a diseased gallbladder was resected. TSG students were able to ask questions of the program director and the surgeon and vice versa using telesurgery technology. After the procedure, the surgeon met with the students for further discussion. VSG students were able to ask questions of the program director during and after the program. Both groups of students completed a pre- and posttest using remote audience responders. Students' responses from the two groups were compared for selected test and evaluation items. RESULTS: Pre-test (Cronbach's alpha=.10) and post-test (Cronbach's alpha =.28) data were obtained from 73 students in the TSG and.22 and.54 respectively from 69 students in the VSG. A significant increase in laparoscopic anatomy knowledge was observed from pretest to posttest for the VSG (31-55%) and from the TSG (30-61%). The majority of VSG students (68%) indicated the method used to teach was outstanding, and 87% indicated that the program was outstanding in keeping their interest. This is contrasted with only 24% of the TSG group responding that the teaching method was outstanding, and 41% indicated that the program was outstanding in keeping their interest. CONCLUSIONS: Medical students can productively be exposed to surgical methods and living anatomy using telesurgery. The high regard the TSG students had for this program suggests that it can be used effectively to teach and inspire medical students. The positive results have encouraged us to have a backup instructional method such as a tape of the MIS procedure, it apparently does not have the positive impact of live surgery.

Anatomy↗
PubMed2000

The state of the heart. If you thought cholesterol was all you had to worry about, better think again.

As recently as five years ago, doctors thought they had a pretty clear picture of what causes a heart attack. They saw it as a plumbing problem: too much fat in the diet builds up in the blood vessels that feed the heart, creating stoppages that starve the heart of oxygen. It was an elegant model and one that patients could understand. But it's not that simple. Cholesterol, it turns out, is just the starting point of a cascade of interlocking events. Underlying the new research presented at the American Heart Association meeting last week was a clear message: this isn't your father's heart disease anymore.

American Heart Association↗
PubMed2000

Different brain networks mediate task performance in normal aging and AD: defining compensation.

OBJECTIVE: To determine whether the pathologic mechanisms of AD alter the brain networks subserving performance of a verbal recognition task. BACKGROUND: Functional imaging studies comparing task-related activation in AD patients and controls generally have not used network analysis and have not controlled for task difficulty. METHODS: H2 15O PET was used to measure regional cerebral blood flow in 14 patients and 11 healthy elders during the performance of a serial verbal recognition task under two conditions: low demand, with study list size (SLS) equal to one; and titrated demand, with SLS adjusted so that each subject recognized words at 75% accuracy. The Scaled Subprofile Model was used to identify networks of regionally covarying activity across these task conditions. RESULTS: In the elders, higher SLS was associated with the recruitment of a network of brain areas involving left anterior cingulate and anterior insula (R2 = 0.94; p < 0.0001). Three patients also expressed this network. In the remaining patients, higher SLS was associated with the recruitment of an alternate network consisting of left posterior temporal cortex, calcarine cortex, posterior cingulate, and the vermis (R2 = 0.81, p < 0.001). Expression of this network was unrelated to SLS in the elders and more intact AD patients. CONCLUSIONS: The patients' use of the alternate network may indicate compensation for processing deficits. The transition from the normal to the alternate network may indicate a point where brain disease has irreversibly altered brain function and thus may have important implications for therapeutic intervention.

Aged↗
PubMed2000

Chemical pathology

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Journal Article↗
PubMed2000

Cationic liposome and plasmid DNA complexes formed in serum-free medium under optimum transfection condition are negatively charged.

In medium where in vitro transfection is routinely performed, DC-chol liposomes alone were nearly neutral, whereas the DC-chol liposome/DNA complexes were largely negatively charged which changed only slightly at all [liposome]/[DNA] ratios (zeta=-27.1 to -21.8 mV). Three other commercial transfection reagents, Lipofectin(R), LipofectAMINE 2000, and SuperFect, were also largely negatively charged when complexed with DNA. The aggregation of liposomes in medium was prevented by the addition of DNA. Incubation of the complexes in medium did not change their size, charge or lipofection activity for 30 min. These results suggest that, in medium, the liposome/DNA complexes were formed at the time of mixing with negative charges.

Animals↗
PubMed2000

Oxidative cellular damage associated with transformation of Helicobacter pylori from a bacillary to a coccoid form.

Exposure to unfavorable conditions results in the transformation of Helicobacter pylori, a gastric pathogen, from a bacillary form to a coccoid form. The mechanism and pathophysiological significance of this transformation remain unclear. The generation of the superoxide radical by H. pylori has previously been shown to inhibit the bactericidal action of nitric oxide, the concentration of which is relatively high in gastric juice. With the use of chemiluminescence probes, both the quality and quantity of reactive oxygen species generated by H. pylori have now been shown to change markedly during the transformation from the bacillary form to the coccoid form. The transformation of H. pylori was associated with oxidative modification of cellular proteins, including urease, an enzyme required for the survival of this bacterium in acidic gastric juice. Although the cellular abundance of urease protein increased during the transformation, the specific activity of the enzyme decreased and it underwent aggregation. Specific activities of both superoxide dismutase and catalase in H. pylori also decreased markedly during the transformation. The transformation of H. pylori was also associated with oxidative modification of DNA, as revealed by the generation of 8-hydroxyguanine, and subsequent DNA fragment. These observations indicate that oxidative stress elicited by endogenously generated reactive oxygen species might play an important role in the transformation of H. pylori from the bacillary form to the coccoid form.

Bacterial Proteins↗
PubMed2000

When did AIDS begin?

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Acquired Immunodeficiency Syndrome↗
PubMed2000

Laparoscopic ventral and incisional hernia repair in 407 patients.

BACKGROUND: Recurrence rates after primary repair of ventral and incisional hernias range from 25% to 52%. Recurrence after open surgery is less likely if mesh is used, but the wide fascial dissection and required flap creation increase complication rates. Laparoscopic techniques offer an alternative. STUDY DESIGN: To assess the safety and efficacy of laparoscopic ventral and incisional herniorrhaphy, we reviewed the records of all our patients who underwent such a procedure from November 1993 to August 1999. A laparoscopic approach was attempted in all patients considered to require a mesh repair. Patient demographic characteristics, operative details, and outcomes were recorded. RESULTS: Of 415 patients scheduled to undergo laparoscopic ventral or incisional herniorrhaphy, conversion to an open procedure was necessary in 8. All the remaining 407 patients (205 men and 202 women; mean age 53.2 years; range 13 to 88 years) were included in the study. Mean fascial defect size was 100.1 cm2 (range 1 to 480 cm2). In 97% of patients, expanded polytetrafluoroethylene mesh was used. Mean operating time was 97 minutes (range 11 to 270 minutes). Mean estimated blood loss was 35 mL (range 10 to 150 mL). Average hospital stay was 1.8 days (range 0 to 17 days). There were 53 complications (13.0%), including cellulitis of a trocar site, infection requiring mesh removal, prolonged suture pain, persistent seroma, intestinal injury, hematoma or postoperative bleeding, prolonged ileus, urinary retention, respiratory distress, fever, intraabdominal abscess, and trocar site herniation. There were no deaths. During a mean followup time of 23 months (range 1 to 60 months), there were 14 hernia recurrences (3.4%), 6 in patients in whom only a stapling device (no sutures) had been used to secure the mesh to the abdominal wall. CONCLUSIONS: Laparoscopic repair was completed in 98.1% of patients in whom it was attempted. The complication rate was acceptable. A short hospital stay and minimal blood loss were documented. The recurrence rate was 3.4%. Laparoscopic ventral and incisional hernia repair appear to be safe and effective.

Adolescent↗
PubMed2000

Pediatric laparoscopic splenectomy.

BACKGROUND: Lateral laparoscopic splenectomy in adults, first reported in 1991, was begun with children in 1993. METHODS: The authors reviewed records of 59 patients 2 to 17 years old who underwent laparoscopic splenectomy by the lateral approach between 1994 and 1998 at four medical centers. Patients received prophylactic penicillin or vaccinations preoperatively. RESULTS: Of the 59 patients, 51 required splenectomy for one of the following conditions: idiopathic thrombocytopenic purpura, hereditary spherocytosis, or sickle-cell disease. Splenomegaly was found in 86% of the patients, and ten accessory spleens were resected. No deaths or infection occurred, and only three patients had perioperative complications: acute chest crisis, small diaphragmatic injury, and intraoperative hemorrhage. One operation was converted to a minilaparatomy because of difficulty with specimen extraction. CONCLUSIONS: Pediatric laparoscopic splenectomy is safe and effective, resulting in little blood loss, rapid recovery, and a good cosmetic outcome.

Adolescent↗