An improved survival model of hypoxia/ischaemia in the piglet suitable for neuroprotection studies

The purpose of this study was to develop a newborn piglet model of hypoxia/ischaemia which would better emulate the clinical situation in the asphyxiated human neonate and produce a consistent degree of histopathological injury following the insult. One-day-old piglets (n=18) were anaesthetised with a mixture of propofol (10 mg/kg/h) and alfentinal (55.5 microg/kg/h) i.v. The piglets were intubated and ventilated. Physiological variables were monitored continuously. Hypoxia was induced by decreasing the inspired oxygen (FiO(2)) to 3-4% and adjusting FiO(2) to maintain the cerebral function monitor peak amplitude at < or =5 microV. The duration of the mild insult was 20 min while the severe insult was 30 min which included 10 min where the blood pressure was allowed to fall below 70% of baseline. Control piglets (n=4 of 18) were subjected to the same protocol except for the hypoxic/ischaemic insult. The piglets were allowed to recover from anaesthesia then euthanased 72 h after the insult. The brains were perfusion-fixed, removed and embedded in paraffin. Coronal sections were stained by haematoxylin/eosin. A blinded observer examined the frontal and parietal cortex, hippocampus, basal ganglia, thalamus and cerebellum for the degree of damage. The total mean histology score for the five areas of the brain for the severe insult was 15.6+/-4.4 (mean +/-S.D., n=7), whereas no damage was seen in either the mild insult (n=4) or control groups. This 'severe damage' model produces a consistent level of damage and will prove useful for examining potential neuroprotective therapies in the neonatal brain.

Soluble CD137 (4-1BB) ligand is released following leukocyte activation and is found in sera of patients with hematological malignancies

Expression of CD137 ligand (4-1BBL), a member of the TNF family of proteins, has been reported on several types of APCs, various carcinoma cells, and can be induced on activated T cells. In this study, we report that the soluble ligand was released constitutively at low levels from leukocytes and at higher levels following cellular activation. Release from cells was blocked by addition of a metalloproteinase inhibitor which concomitantly caused the accumulation of 4-1BBL on the cell surface. In addition, we show that a soluble form of 4-1BBL was present at high levels in the sera of some patients with various hematological diseases, but only at low levels in healthy donors. Soluble 4-1BBL was active in that it competed with recombinant 4-1BBL for binding to the 4-1BB receptor and was able to costimulate IL-2 and IFN-gamma release from peripheral T cells. These results indicate that the release of soluble 4-1BBL from the cell surface is mediated by one or more sheddases and likely regulates 4-1BB-4-1BBL interactions between cells in vivo. Cleavage of 4-1BBL to an active soluble form would alter both proximal and distal cellular responses, including cell survival and costimulatory or inflammatory responses, that are mediated through the 4-1BB pathway. This, in turn, would likely alter disease progression or outcome.

Women, guilt, and home computers

This paper will discuss, with reference to a field study examining attitudinal, emotional, and physical barriers, some of the ways in which some women are currently restricted in accessing networked computers in their own households. The study was prompted by a concern that current discussions focussing on the potential of computer-supported distance learning do not acknowledge differences in women's experience of family and household which may impinge on access. It will be suggested here that the domestic arrangements of space and time with home computers are crucial factors in supporting women's access to learning and personal development via the Internet.

Predicting polyposis severity by proctoscopy: how reliable is it?

PURPOSE

Patients with familial adenomatous polyposis need prophylactic colectomy and ileorectal anastomosis or restorative proctocolectomy. Preoperative rectal polyp counts have been used as one factor to determine which operation should be done, triaging patients according to risk of rectal cancer or completion proctectomy after ileorectal anastomosis. This study was designed to examine the reliability of preoperative proctoscopy in predicting familial adenomatous polyposis severity and outcome after ileorectal anastomosis.

METHODS

Familial adenomatous polyposis patients were categorized according to preoperative proctoscopy as follows: Group 1, 5 or fewer adenomas; Group 2, 6 to 19 adenomas; Group 3, 20 or more adenomas. Familial adenomatous polyposis severity was defined as mild if there were < 1,000 polyps in the colon at colectomy and severe if there were > 1,000 polyps.

RESULTS

A total of 213 patients were reviewed, 80 in Group 1, 59 in Group 2, and 74 in Group 3. There was no difference among the groups in mean age at presentation. Patients with fewer than five rectal adenomas were predominately females. They rarely had symptoms (22.8 percent), had mostly mild polyposis (86.5 percent), and in 74 of 80 cases underwent ileorectal anastomosis. Only six underwent restorative proctocolectomy. Of those having an ileorectal anastomosis, five needed later proctectomy, none for cancer. Patients with 6 to 19 rectal polyps were a similar group to those with 5 or fewer. Most were asymptomatic (67.8 percent), most had mild polyposis (81.6 percent), and 54 of 59 underwent ileorectal anastomosis (5 had restorative proctocolectomy). Only 3 of the 54 having ileorectal anastomosis needed subsequent proctectomy, 2 for rectal cancer. The patients with 20 or more rectal polyps were different. They usually presented with symptoms (86 percent), the majority (56.6 percent) had severe polyposis, and only 50 percent (37/74) underwent ileorectal anastomosis, the other half having restorative proctocolectomy. Of the 37 patients with an ileorectal anastomosis, 13 needed later proctectomy (35.1 percent), 4 for cancer (10.8 percent).

CONCLUSION

Fewer than five rectal adenomas at presentation almost always predicts mild disease, and patients do well after ileorectal anastomosis. Twenty or more adenomas usually means severe disease. Patients with 6 to 19 adenomas are often mildly affected, but their phenotype is less benign than that of patients with fewer than five polyps. Although not foolproof, proctoscopy is a useful test in triaging patients with familial adenomatous polyposis according to disease severity.

Perinatal factors and preterm delivery in an Irish obstetric population

The aim of this study was to ascertain the incidence of preterm delivery, the associated etiological factors and consequent perinatal mortality in an Irish obstetrical population. All deliveries between 24 + 0 and 36 + 6 weeks of gestation that occurred during the five year period 1992-1996 were included in the study. The overall group of preterm deliveries was also analyzed separately as an early preterm group (24 + 0-31 + 6 weeks gestation) and a late preterm group (32 + 0-36 + 6 weeks gestation). The overall incidence of preterm delivery was 5.5% (n = 683) with 1% (n = 122) occurring in the early preterm group and 4.5% (n = 561) in the late preterm group. The etiological factors contributing to preterm delivery in our population together with their frequency of occurrence in both early and late preterm groups are outlined. Spontaneous unexplained preterm delivery, multiple pregnancy, and hypertensive disorders of pregnancy were the commonest etiological factors for preterm delivery. The perinatal mortality rate (PMR) was 57 per 1000 (n = 39) in the preterm group overall with a 213/1000 PMR in the early preterm group and a 23/1000 PMR in the late preterm group.

History of the methamphetamine problem

Methamphetamine, called meth, crystal, or speed, is a central nervous system stimulant that can be injected, smoked, snorted, or ingested orally; prolonged use at high levels results in dependence. Methamphetamine (MA) is a derivative of amphetamine, which was widely prescribed in the 1950s and 1960s as a medication for depression and obesity, reaching a peak of 31 million prescriptions in the United States in 1967. Until the late 1980s, illicit use and manufacture of MA was endemic to California, but the MA user population has recently broadened in nature and in regional distribution, with increased use occurring in midwestern states. An estimated 4.7 million Americans (2.1% of the U.S. population) have tried MA at some time in their lives. Short- and long-term health effects of MA use include stroke, cardiac arrhythmia, stomach cramps, shaking, anxiety, insomnia, paranoia, hallucinations, and structural changes to the brain. Children of MA abusers are at risk of neglect and abuse, and the use of MA by pregnant women can cause growth retardation, premature birth, and developmental disorders in neonates and enduring cognitive deficits in children. MA-related deaths and admissions to hospital emergency rooms are increasing. Although inpatient hospitalization may be indicated to treat severe cases of long-term MA dependence, optimum treatment for MA abusers relies on an intensive outpatient setting with three to five visits per week of comprehensive counseling for at least the first three months. The burgeoning problems of increased MA use must be addressed by adequate treatment programs suitable for a variety of user types.

Evaluation of a skin cancer prevention module for nurses: change in knowledge, self-efficacy, and attitudes

PURPOSE

The purpose of this study was to evaluate the effectiveness of a 1-week didactic and clinical skin cancer prevention training module. The evaluation assessed both the immediate and the 3-month effects of the module on nurse participants. In addition, this study assessed whether the module had any secondary effects on skin cancer practices, including perceived support from colleagues, resources, time, and perceived responsibility to conduct skin cancer screening activities and education.

METHODS

A quasi-experimental design with 32 intervention and 87 comparison subjects was employed. Instruments developed and validated specifically for this study were used to assess knowledge, self-efficacy, priority of skin cancer, and organizational level constructs.

RESULTS

The findings indicate that the module significantly increased general and prevention knowledge as well as screening ability; the increase was stable over time. The module was also found to improve self-efficacy to screen and to educate. There was no effect on the organizational-level constructs.

CONCLUSIONS

Baseline knowledge assessments validated other studies indicating that nurses need more education about skin cancer. Despite promising results from program participants, system-level barriers could impose substantial barriers to implementation in health care practice. Knowledgeable nurses must educate their colleagues, their supervisors, and the public about the priority of skin cancer screening and develop strategies for creating organizational change to increase the likelihood that screening and patient education will occur for people at risk for skin cancer.

Cellular immunity delimits adenoviral gene therapy strategies for the treatment of neoplastic diseases

BACKGROUND

Adenoviral gene therapy is a promising new approach for the treatment of neoplastic diseases. To design rational clinical trials and distinguish the effects of therapeutic transgene expression from those caused by viral infection alone, the immune response to the vector must be understood. In these experiments, we further define cellular immunity to recombinant adenovirus.

METHODS

The immune response to hepatic adenoviral gene transfer was studied in infected mice by depleting T cells with an anti-CD3 antibody, measuring splenocyte cytokine production, determining the impact of transgene expression on inflammation, and assessing liver MHC protein expression.

RESULTS

The cellular immune response to recombinant adenovirus is (1) averted by T lymphocyte depletion, (2) marked by a TH1 response with increased IL-2 production, (3) directed against both the transgene product and viral proteins, and (4) associated with increased hepatocyte MHC Class I expression.

CONCLUSIONS

It is necessary to take into consideration the constraints imposed by the immunogenicity of recombinant adenovirus and its transient transgene expression in the clinical application of adenoviral gene transfer for the treatment of cancer.

Evaluation of simethicone for the treatment of postoperative abdominal discomfort in infants

STUDY OBJECTIVE

To determine whether abdominal discomfort is a cause for distress symptoms in infants following administration of inhalational anesthesia, and to evaluate the effectiveness of simethicone in treating this discomfort.

DESIGN

Randomized, double-blinded study.

SETTING

Large tertiary care, university-based medical center.

PATIENTS

175 ASA physical status I and II infants under 28 months of age who underwent an inhalational anesthetic for a variety of procedures that were expected to cause relatively little pain.

INTERVENTIONS

Children were assessed for the presence of postoperative abdominal discomfort, and, if evident, were randomly given either simethicone or placebo in a double-blinded fashion.

MEASUREMENTS AND MAIN RESULTS

Abdominal discomfort was measured using the Faces Legs Activity Cry and Consolability (FLACC) Behavioral Pain Scale. Scores were recorded pre-drug; at 10, 20, and 30 minutes following drug administration; and at discharge. If discomfort had not resolved within 15 minutes after the drug was given, routine analgesics or other medications were administered. Abdominal girth was measured preoperatively, on admission into the postanesthesia care unit (PACU), and at discharge. 21% of infants exhibited symptoms of abdominal discomfort postoperatively. Younger infants were at greater risk for this condition. 36 infants were given either placebo or simethicone, and of these, infants who received simethicone were comfortable earlier and required fewer rescue medications compared with placebo. There were no differences in ability to tolerate oral fluids prior to discharge or in the length of stay in the PACU.

CONCLUSIONS

Simethicone is a safe and inexpensive medication that may provide anesthesiologists with an effective treatment choice for suspected postoperative abdominal discomfort in infants.

Efficient adenoviral-mediated murine neonatal small intestinal gene transfer is dependent on alpha(v) integrin expression

BACKGROUND/PURPOSE

Clinical application of gene therapy for patients who have inflammatory bowel disease or short bowel syndrome will require the development of new strategies to improve the efficiency of small intestinal gene transfer. Previously, the authors developed a method for adenoviral-mediated small intestinal gene transfer in vivo in neonatal and adult mice. The present study evaluates the hypothesis that the integrins alpha(v)beta3 and alpha(v)beta5, the secondary receptors for adenoviral internalization, play a facilitative role in neonatal murine adenoviral-mediated small intestinal gene transfer.

METHODS

Immunohistochemical techniques identified the integrin alpha(v)beta3 and the integrin subcomponents alpha(v), beta3, and beta5 in neonatal and adult small intestine. The effects of integrin receptor antagonists on transgene expression was also studied in our neonatal model of adenoviral-mediated small intestinal gene transfer in vivo.

RESULTS

Gene transfer was significantly decreased by the addition of integrin receptor antagonists versus control peptide. Integrin alpha(v)beta3 and integrin subcomponent alpha(v), beta3, and beta5 are expressed in neonatal and adult small intestine. Integrin antagonists administered simultaneously blocked efficient adenoviral-mediated neonatal small intestinal gene transfer in vivo compared with control peptide.

CONCLUSION

Strategies to upregulate integrin expression may improve adenoviral-mediated small intestinal gene transfer.

Engineering tissue-specific expression of a recombinant adenovirus: selective transgene transcription in the pancreas using the amylase promoter

Recombinant adenovirus accomplishes highly efficient gene transfer in vivo. Adenoviral vectors would be more attractive vehicles for gene therapy if transgene expression was inducible and restricted to the target tissue. In these studies, we hypothesized that selective transgene expression of a recombinant adenovirus could be accomplished by using a tissue-specific promoter of transcription. A replication-defective adenoviral vector was engineered to express the lacZ marker gene under control of the murine pancreatic amylase promoter. Expression of this vector occurred exclusively in the pancreas in neonatal and adult mice, while a similar vector with a constitutive promoter accomplished transgene expression in several organs. Within the adenoviral construct, the amylase promoter retained its ability to be induced by dexamethasone and insulin. This model will serve as a paradigm for selective and inducible adenoviral transgene expression.

Effect of adenoviral early genes and the host immune system on in vivo pancreatic gene transfer in the mouse

Gene transfer technology may provide a novel approach to treatment for pancreatic diseases. Recombinant adenovirus achieves efficient gene transfer in vivo. In this study, a murine model of adenoviral-mediated pancreatic gene transfer was developed, and the factors responsible for adenoviral elimination were investigated. Three days after direct pancreatic injection of a replication-defective adenovirus containing the lacZ transgene, a high proportion (76.8 +/- 6.7%) of pancreatic cells expressed beta-galactosidase, the gene product. Gene expression was absent by 28 days posttransduction. In immunodeficient mice, beta-galactosidase expression persisted with 20.0 +/- 6.0% of pancreatic cells staining positive 60 days after viral transduction. To test whether early viral proteins are the antigenic components responsible for the potent antiviral immune response, normal mice were injected with different adenoviral vectors containing early gene deletions. Vectors containing deletions in early region 2 or 4 expressed beta-galactosidase at 28 days. Presently available adenoviral vectors engineered to avoid this response offer minimal improvements in transgene duration. Further vector modifications or alternative strategies are needed to achieve stable pancreatic adenoviral transgene expression.

Allergen-induced cytokine production in atopic disease and its relationship to disease severity

The Th2 cytokines, interleukin (IL)-4 and IL-5, have an important role in atopic disease. CD30 is a transmembrane molecule that may be expressed on a proportion of activated T-lymphocytes and has been reported to be a marker for Th2 phenotype. Our objective was to compare the in vitro cytokine responses and CD30 expression of peripheral blood mononuclear cells (PBMCs) to stimulation with house dust mite antigen (Dermatophagoides pteronyssinus) in atopic asthmatics, atopic nonasthmatics, and normal subjects, and to see if atopic asthmatic cytokine production correlated with symptomatic disease activity and whether cytokine production was allergen-specific. Eighteen atopic asthmatics (all were allocated a symptomatic disease score), 6 atopic nonasthmatics, and 7 healthy nonatopic individuals were studied. Resting serum IL-4 levels were measured, then PBMCs were separated using Lymphoprep density centrifugation and cultured in modified RPMI 1640 medium. PBMCs were stimulated with IL-2 alone or with D. pteronyssinus (1,000 subcutaneous units/ml) with IL-2 and harvested after 5 and 10 d. Using monoclonal antibodies and flow cytometry we obtained the percentage of CD4+ T cells expressing CD30 and the intensity of CD30 staining. Culture supernatants were analyzed for IL-4 and interferon gamma (IFN-gamma) using an enzyme-linked immunosorbent assay. In 9 atopic asthmatics PBMCs were also stimulated nonspecifically using phytohemagglutinin (PHA). IL-4 was detectable in the serum of atopic subjects but not in normal subjects. Stimulation of PBMCs with D. pteronyssinus produced significant amounts of IL-4 in atopic asthmatics and atopic nonasthmatics, but minimal quantities in normal subjects. Much lower levels of IFN-gamma were produced by atopic asthmatics in response to D. pteronyssinus compared to atopic nonasthmatics. IFN-gamma levels had an inverse correlation with asthmatic symptom score. CD4+ T-cell expression of CD30 also correlated inversely with IFN-gamma production and IFN-gamma:IL-4 ratio. PHA produced minimal levels of IL-4 compared to specific allergen stimulation. It is concluded that different groups of atopic patients exhibit different patterns of allergen-induced cytokine production. In vitro allergen-induced cytokine production in atopic asthmatics correlated with symptomatic disease activity, and is allergen-specific.

Adenoviral-mediated gene transfer to murine small intestine is more efficient in neonates than adults

PURPOSE

The authors sought to assess the feasibility of in vivo gene transfer to the small intestine using recombinant adenovirus in neonatal and adult mice.

METHODS

H5.010CMVlacZ is a replication-defective, E1-deleted human type 5 adenovirus, which contains the lacZ gene under the control of a cytomegalovirus promoter and enhancer. The lacZ gene was used as a marker because its gene product, beta-galactosidase, is readily detected by X-gal histochemistry. Sixty neonatal (3 to 5 days old) and 45 adult (6 to 8 weeks old) C57BL/6 mice were investigated. Intestinal gene transfer was attempted with H5.010CMVlacZ by intraperitoneal (i.p.), intraluminal (IL), and intramural (i.m.) injection. Based on prior studies, the optimal dose of H5.010CMVlacZ was 1 x 10(8) plaque forming units (pfu/mL). Control animals received saline injections. Gene transfer on repeat administration of adenovirus has been shown to be prevented by neutralizing antibody. To determine if neonatal inoculation induced a humoral immune response, neonates (n = 5) that received i.p. injections were rechallenged with intravenous H5.010CMV alkphos, a similar adenoviral construct containing the alkaline phosphatase marker gene. Serum samples were analyzed by Western blot to detect the presence of adenoviral-specific antibody.

RESULTS

Gene transfer to neonatal small intestine was successful by IL gastric (n = 8/10), IL jejunal (n = 9/10) and i.p. (n = 10/10) routes 2 days after injection. Macroscopic staining was present in 90% of standardized 2-cm small bowel segments. Transgene expression was identified in intestinal smooth muscle, serosa, and epithelium. Gene transfer to the adult small intestine was successful by IL jejunal (n = 4/5), i.m. (n = 5/5), and i.p. (n = 1/5) injection of adenoviruslacZ with focal staining (< 5% of 2-cm segments) in epithelium including crypts, muscle, and serosa. Three weeks after i.p. H5.010CMVlacZ in neonates, intravenous injection with H5.010CMValkphos resulted in hepatic transgene expression (n = 4/5) that was indistinguishable from a primary intravenous inoculation; persistent, lacZ expression was not detectable in the liver or intestine (n = 0/5). Western blot analysis detected adenoviral-specific antibodies after adult IM but not after neonatal i.p. injection. Furthermore, 3 weeks after neonatal i.p. injection repeat administration by the i.m. route was successful (n = 4/ 4).

CONCLUSION

Gene transfer to neonatal and adult small intestine is feasible using recombinant adenovirus and is more efficient in neonates as indicated by increased surface area of marker gene expression, effectiveness of intraperitoneal delivery, and the ability to readminister recombinant adenovirus.

Immunologic barriers to hepatic adenoviral gene therapy for transplantation

Adenoviral gene transfer has potential use to attenuate the immunogenicity of hepatic allografts. However, the clinical application of adenoviral gene therapy is currently impeded by the potent host immune response to the virus that limits the duration of its effects. In these studies, we identify the cellular and humoral immune responses to recombinant adenovirus in the liver of mice and define the immunologic barriers to the successful application of this technology to transplantation. The immunobiology of recombinant adenovirus was studied in mouse liver using vectors containing the lacZ and alkaline phosphatase marker genes. The duration of transgene expression was studied in various immunodeficient mice to determine the mechanism of viral clearance. Adoptive transfer of serum to B lymphocyte deficient mice and neutralizing antibody assays were used to define the antiviral humoral response. Hepatic adenoviral transgene expression was prolonged in animals deficient in CD4+ or CD8+ T cells indicating their importance in viral clearance. Unexpectedly, mice lacking B lymphocytes also had delayed elimination of virus suggesting that B cells play a role in the primary immune response. Effective repeat gene transfer was blocked by adenoviral-specific neutralizing antibody. Therefore, a T lymphocyte response results in viral elimination after a primary intravenous inoculation of recombinant adenovirus and a potent humoral response inhibits effective repeat adenoviral gene transfer. The immunogenicity of the vector must be overcome for adenoviral gene therapy to have therapeutic application for hepatic transplantation.

Occupational risk factors for the first-onset and subsequent course of low back trouble. A study of serving police officers

STUDY DESIGN

A survey of occupational risks for low back trouble in two police forces discordant for one known physical stressor (wearing body armor weighing approximately 8.5 kg.

OBJECTIVES

To determine the hazard for first-onset and subsequent course of low back trouble associated with occupational physical and psychosocial stressors.

SUMMARY OF BACKGROUND DATA

Various occupational physical stressor have been associated with the prevalence of back pain, but their relationship with first-onset low back trouble is uncertain. Psychosocial factors reportedly are important determinants of chronicity.

METHODS

Anamnestic data on low back trouble were collected from representative random samples of "exposed" and control forces, along with variables describing exposure to occupational physical stressors and sports results. Psychometric tests were administered.

RESULTS

Occupational risk factors for first-onset low back trouble were determined from lifetables based on officers with no previous back pain history. Survival time to first onset was affected adversely by wearing body armor and, less so, by vehicular exposure and sports participation. The proportion with persistent (chronic) trouble did not depend on length of exposure since onset, but longer service was associated with recurrent episodes. Chronicity was related to distress and blaming police work. Work loss was associated with blaming work and wearing body armor. Changing to lighter duties after development of low back trouble occurred rarely.

CONCLUSIONS

Exposure to occupational physical stress seems detrimental; It reduced survival time to first-onset of low back trouble. Recurrence was associated with time since onset, but persistent trouble was not. Sports participation was a risk if occupational hazards were high.

Neuroleptic malignant syndrome in a trauma patient

Neuroleptic malignant syndrome is a rare complication of antipsychotic medications. This paper describes the case of a trauma patient who received haloperidol and droperidol for severe agitation, developed neuroleptic malignant syndrome, and was treated successfully with dantrolene sodium, and also provides a review of the literature.