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Biomedical subjects

J Francis

Publications and source records attributed to J Francis.

At least 19 recordsLinked to original sources

Pre-pregnancy body mass index and pregnancy outcomes.

OBJECTIVE: To determine the effect of maternal pre-pregnancy BMI on pregnancy outcomes. METHODS: Pregnancy cohort recruited pregnancies between 16 and 18 weeks. BMI evaluated underweight, BMI<18.5, normal, BMI 18.5-25, overweight BMI 25-30, and obese BMI>30 women. RESULTS: Pre-pregnancy BMI classified 331 women as underweight (11.7%), 1982 normal (69.9%), 326 overweight (11.5%), and 188 as obese (6.6%). Obese women were more likely to develop gestational diabetes (p<0.001), hypertension (p<0.001), preeclampsia (p<0.001), need labor induction (p<0.001), cesarean delivery for fetal distress (p<0.001), postpartum hemorrhage (p=0.003), need neonatal resuscitation (p=0.001) and deliver hypoglycemic infants (p=0.007). Being underweight is correlated with fetal growth restriction (p=0.001). CONCLUSION: Pre-pregnancy obesity is a risk factor for gestational diabetes, preeclampsia, labor induction, cesarean for fetal distress, postpartum hemorrhage and neonatal hypoglycemic and need for resuscitation. Being underweight is risk factor for fetal growth restriction.

Adult↗

Immune responses to AAV in a phase I study for Canavan disease.

BACKGROUND: Canavan disease is a rare leukodystrophy with no current treatment. rAAV-ASPA has been developed for gene delivery to the central nervous system (CNS) for Canavan disease. This study represents the first use of a viral vector in an attempt to ameliorate a neurodegenerative disorder. METHODS: Subjects received intracranial infusions via six cranial burr holes. Adeno-associated virus, serotype 2 (AAV2), mediated intraparenchymal delivery of the human aspartoacylase cDNA at a maximum dose of 1 x 10(12) vector genomes per subject. The immune response and safety profiles were monitored in the follow-up of ten subjects. RESULTS: Following rAAV2 administration, we found no evidence of AAV2 neutralizing antibody titers in serum for the majority of subjects tested (7/10). In a subset (3/10) of subjects, low to moderately high levels of AAV2 neutralizing antibody with respect to baseline were detected. In all subjects, there were minimal systemic signs of inflammation or immune stimulation. In subjects with catheter access to the brain lateral ventricle, cerebrospinal fluid was examined and there was a complete absence of neutralizing antibody titers with no overt signs of brain inflammation. CONCLUSIONS: rAAV2 vector administration to the human CNS appears well tolerated. The low levels of immune response to AAV2 detected in 3/10 subjects in this study suggest at this dose and with intraparenchymal administration this approach is relatively safe. Long-term monitoring of subjects and expansion to phase II/III will be necessary in order to make definitive statements on safety and efficacy.

Amidohydrolases↗

[Potential antinociceptive mechanisms of botulinum toxin].

Botulinum toxin has been used in pain therapy for several years. Its application in migraine and headaches is particularly interesting. Clinical results have not yet been definitely conclusive, and a uniform model of the mode of action has not been established either. Apart from a purely muscular effect, a direct antinociceptive effect of botulinum toxin has been found in patients, in the preclinical model, and in a clinical pain model. This is contradicted by negative observations in the clinical model of pain, which might be related to methodological deficits. Further basics need to be worked out before arriving at any final result. Clinical studies with patients and pain models should then follow. Studying botulinum toxin within the context of pain will also provide many new insights into pain therapy in general. In which pain model botulinum toxin may play a role in the future, has to be awaited.

Analgesics, Non-Narcotic↗

Natural history of Canavan disease revealed by proton magnetic resonance spectroscopy (1H-MRS) and diffusion-weighted MRI.

Canavan disease is a childhood leukodystrophy caused by mutations in the gene for human aspartoacylase ( ASPA), which leads to an abnormal accumulation of the substrate molecule N-acetyl-aspartate (NAA) in the brain. This study was designed to model the natural history of Canavan disease using MRI and proton magnetic resonance spectroscopy ( (1)H-MRS). NAA and various indices of brain structure (morphology, quantitative T1, fractional anisotropy, apparent diffusion coefficient) were measured in white and gray matter regions during the progression of Canavan disease. A mixed-effects statistical model was used to fit all outcome measures. Longitudinal data from 28 Canavan patients were directly compared in each brain region with reference data obtained from normal, age-matched pediatric subjects. The resultant model can be used to non-invasively monitor the natural history of Canavan disease or related leukodystrophies in future studies involving drug, gene therapy, or stem cell treatments.

Age Factors↗

Effects of AAV-2-mediated aspartoacylase gene transfer in the tremor rat model of Canavan disease.

The tremor rat is a spontaneous epilepsy model with a seizure phenotype caused by a deletion in the aspartoacylase (ASPA) gene. The absence of ASPA expression in these animals results in undetectable levels of enzyme activity and the accumulation of the substrate N-acetyl-aspartate (NAA) in brain, leading to generalized myelin vacuolation and severe motor and cognitive impairment. In support of human gene therapy for CD, recombinant adeno-associated viral vector (AAV-2) expressing ASPA was stereotactically delivered to the tremor rat brain and effects on the mutant phenotype were measured. AAV-ASPA gene transfer resulted in elevated aspartoacylase bioactivity compared to untreated mutant animals and elicited a significant decrease in the pathologically elevated whole-brain NAA levels. Assessment of motor function via quantitative rotorod testing demonstrated that rats injected with AAV-ASPA significantly improved on tests of balance and coordinated locomotion compared to animals receiving control vectors. This study provides evidence that AAV-2-mediated aspartoacylase gene transfer to the brain improves biochemical and behavioral deficits in tremor rat mutants (tm/tm) and supports the rationale of human gene transfer for Canavan disease.

Amidohydrolases↗

Functional interactions of antiapoptotic proteins and tumor necrosis factor in the context of a replication-competent adenovirus.

Replication-selective oncolytic adenoviruses hold promise, but novel mechanisms must be identified to maximize intratumoral virus persistence, spread and therapeutic transgene-carrying capacity while maintaining safety. One of the main approaches to engineering cancer-selectivity has been to delete a viral gene that is theoretically expendable in cancer cells. Results with this approach have been mixed, however, as evidenced by controversy over Onyx-015 (E1B-55kD(-)) selectivity. We hypothesized that the functional redundancy between viral gene products might limit selectivity and/or potency with this approach. Antiviral immune inducers of apoptosis (eg TNF-alpha) have not been thoroughly investigated in previous studies. We therefore explored whether deletion of functionally redundant viral genes, E1B-19kD and E3B, both independently antagonize TNF-alpha, could lead to enhanced oncolytic potency while maintaining selectivity. Since tumors have numerous blocks in apoptotic pathways, we hypothesized that deletion of one or both gene regions would result in cancer-selectivity in the presence of TNF-alpha. We have previously shown that the E1B-19kD deletion resulted in enhanced viral spread in vitro and in immunocompetent tumor models in vivo. In contrast, the impact of E3B deletion, especially its in vitro selectivity and potency, was not thoroughly characterized, although it resulted in rapid immune-mediated viral clearance in vivo. Furthermore, previous publications indicated that double-deleted mutants have selectivity but unsatisfactory efficacy. We compared the selectivity and potency of E1B-19kD(-), E3B(-) and E1B-19kD(-)/E3B(-) mutants to wild-type adenovirus. In cancer cells, the E1B-19kD(-) mutant had superior replication, spread and cytolysis (+) or (-) TNF-alpha; deletion of both E1B-19kD and E3B was relatively deleterious. In normal cells without TNF-alpha, similar results were obtained. In contrast, all three mutants were significantly inhibited in the presence of TNF-alpha. In immunocompetent mice, all three mutants were significantly inhibited in normal tissue. In tumors, only the E1B-19kD(-) mutant demonstrated enhanced replication, spread and antitumoral efficacy. Therefore, E1B-19kD deletion and E3B retention should be incorporated in oncolytic adenoviruses for enhanced safety and efficacy. In addition, functional redundant viral genes and their biological mediators/targets need to be carefully examined for the next generation of gene-deleted oncolytic viruses.

Adenoviridae↗

Serum vitamin D levels in children with cystic fibrosis.

Osteopenia is increasingly recognized in adults with cystic fibrosis (CF), and is potentially related to vitamin D deficiency in both adulthood and childhood. Vitamin D supplements are recommended and prescribed to all pancreatic-insufficient patients. We aimed to ascertain whether vitamin D deficiency in children with CF was prevalent. 25-hydroxyvitamin D (25-OHD) was measured in 290 children attending a specialist pediatric CF clinic for annual assessment. 25-OHD levels were compared with reference values and to other biochemical markers, lung function, and growth. Levels were also analyzed by pancreatic status and by the presence of CF-related liver disease. Median 25-OHD was 65 (range, 9-190) nmol/l. One percent had levels below 15 nmol/l, and 6% had levels less than 25 nmol/l. Levels were lower in adolescents (P < 0.001) and during the "winter" months (P < 0.001). No relationship was found with pancreatic status or liver disease. In conclusion, the majority of children had normal 25-OHD levels. Interpretation is difficult due to a lack of knowledge of optimal levels of 25-OHD required for healthy bone accretion. Lower levels in adolescents may be a precursor to low levels in adulthood, and did not seem to be simply related to poor compliance with supplementation. This may reflect normal physiology.

Adolescent↗

Investigation into the role of cephalic stimulation of acid secretion on gastric emptying and appetite following a soup meal using the gastric acid inhibitor omeprazole.

We previously showed that oral administration of a liquid soup preload was associated with a slower rate of gastric emptying and suppressed appetite more compared with intragastric administration of the same soup [Appetite 31(1998)377]. The present study was designed to investigate whether these results could be explained by the cephalic stimulation of acid secretion induced by oral administration. Eight healthy male subjects took part in a double-blind placebo controlled study comparing the effects of omeprazole and placebo on gastric emptying, appetite ratings and subsequent food intake following the ingestion of a liquid soup. Subjects were administered with a single oral dose of 80 mg omeprazole or placebo 3 h prior to ingesting the radiolabelled soup preload (400 kcal; 425 ml) over 15 min. Ratings of hunger, desire to eat and fullness were recorded over 135 min and gastric emptying was measured by scintigraphy. Food intake was evaluated from a test meal (yoghurt drink) given 120 min after the end of the soup ingestion. Analysis of data showed that there was no significant difference between omeprazole and placebo in gastric emptying, appetite or subsequent energy intake from the test meal. The results suggest that gastric acid secretion is not responsible for the differences in gastric emptying and appetite observed between intragastrically infused and orally administered soup preloads.

Administration, Oral↗

Best Practice No 175. Guidelines for virological and non-viral serological examination of specimens in routine diagnostic microbiological laboratories.

Viral examination is routinely carried out in most routine diagnostic microbiology laboratories. Most often, this comprises the detection of viral antigens and antibodies, and less commonly the isolation of viruses and the detection of viral nucleic acids. However, there are no standards or guidelines available for processing these specimens in routine diagnostic laboratories or for referral to specialist virology centres or units. Clinical Pathology Accreditation (CPA) has defined standards for assessing the quality of service provided by laboratories, but these do not include the scientific and technical aspects of provision of service. The Association of Medical Microbiologists has recently published Standards for Laboratory practice in medical microbiology, which covers scientific and technical aspects of provision of microbiology service, mainly bacteriological examination of specimens in routine diagnostic microbiology laboratories. These guidelines are complementary to the CPA guidelines and aim to ensure a consistent and high quality service. This article presents guidelines for the examination of specimens for the diagnosis of viral infections.

Benchmarking↗

Best Practice No 174. Best practice guidelines for the examination of specimens for the diagnosis of parasitic infections in routine diagnostic laboratories.

Although most routine microbiology diagnostic laboratories process specimens for the diagnosis of parasitic infections, there are no best practice guidelines either for processing or for referral to specialist centres. Microscopy for parasites is most often requested on faecal samples, but urine, sputum, liver aspirates, duodenal aspirates, bile, corneal scrapings, contact lens fluid, and tissue are also encountered. Diagnosis of certain parasitic infections requires serology or polymerase chain reaction. These are undertaken in specialist laboratories, which should be consulted for expert advice on diagnosis and management of parasitic infections. Clinical Pathology Accreditation UK (CPA) has defined standards for assessing the quality of service provided by laboratories, but these do not include scientific and technical aspects. The Association of Medical Microbiologists has recently published Standards for laboratory practice in medical microbiology, which covers scientific and technical aspects, mainly bacteriological examination of specimens in routine diagnostic microbiology laboratories. These guidelines are complementary to the CPA standards and aim to ensure a consistent and high quality of service. This article provides best practice guidelines for the diagnosis of parasitic infections.

Biopsy↗

To clip or not to clip? Noseclips for spirometry.

The use of noseclips for open-circuit spirometry is sporadic, despite guidelines encouraging their use. The authors aimed to evaluate whether noseclips significantly affected measurements of forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) in children attending a tertiary, paediatric respiratory centre. Children attending the asthma and cystic fibrosis (CF) clinics were asked to perform two sets of spirometry, one with and one without noseclips in random order, 20-min apart. Paired data was obtained on 62 patients (32 asthma, 30 CF) with a median age of 11.4 yrs (range 7.2-17.2 yrs). There were no systematic differences in FEV1 or FVC measured with and without noseclips, although seven children (11%) had clinically significant differences in FEV1 of >190 mL. There is no clear advantage to wearing noseclips when performing open-circuit spirometry. Individuals should be assessed to ascertain their optimal technique, which should then be used consistently in clinical practice. Noseclips should probably be retained for research protocols.

Adolescent↗

Kindling induces the mRNA expression of methyl DNA-binding factors in the adult rat hippocampus.

We have investigated the gene expression responses of a family of methyl CpG-binding domain-containing factors (MeCP2, MBD1, MBD2, and MBD3) in the hippocampus of electrically kindled rats. Expression was examined in both amygdala- and partial perforant-pathway-kindled subjects, 24 h and 28 days following the final stimulation. In general, the responses of MBDs 2 and 3 paralleled each another, both temporally and spatially. The expression of both genes was significantly elevated in all hippocampal subfields at 24 h following either the fifth stage 5 seizure (amygdala kindling) or the 15th stimulation of the perforant pathway. This induced expression was transient, however, as the expression of both genes returned to control levels by 28 days. This pattern of response contrasted to that observed for MeCP2 and MBD1. MeCP2 displayed no change in expression either 24 h or 28 days after amygdala kindling, but did display a late-developing, significant increase in expression in the dentate gyrus at 28 days following perforant-pathway kindling. The expression of MBD1 was unchanged by partial perforant-pathway kindling, but was induced in the dentate gyrus 28 days after amygdala kindling. These results demonstrate that electrical kindling alters the hippocampal expression of methyl DNA-binding factors, but does not affect each factor equivalently. The responsive patterns observed suggest that this family of transcriptional regulators can be differentially altered in the hippocampus by seizure activity.

Amygdala↗

Transient forebrain ischemia alters the mRNA expression of methyl DNA-binding factors in the adult rat hippocampus.

We have examined how transient cerebral ischemia affects the mRNA expression of a family of methyl CpG-binding domain (MBD)-containing factors in the rat hippocampus. Our results show that each member of this family is affected by cerebral ischemia challenge, but with differing patterns of responsiveness. At 3, 6 and 12 h following reperfusion, MeCP2 and MBD1 expression is maintained at control levels throughout the hippocampus. At 24 h, MeCP2 and MBD1 are induced in both the CA1 and CA3 subfields. This delayed pattern of induction is in contrast to the responses of MBD2 and MBD3. Both MBD2 and MBD3 display significant changes in expression at early times following reperfusion, although their changes are opposite in direction. MBD2 expression is induced throughout the hippocampal formation at 6 h, and remains elevated at 12 and 24 h. MBD3 expression decreases as early as 3 h following insult in the CA3 and dentate gyrus, and the decreased expression remains in the vulnerable CA1 subfield at 6, 12, and 24 h. Taken together, these results are the first to illustrate that the expression of methyl DNA-binding factors are affected by challenges to the brain, and they also illustrate that each methyl DNA-binding factor responds differently to cerebral ischemic challenge. As each of these family members is associated either directly or indirectly with the inhibition of gene transcription, our results suggest that following cerebral ischemia the normal pattern of transcriptional inhibition provided by these factors may be altered in the hippocampus.

Age Factors↗

Delirium in mechanically ventilated patients: validity and reliability of the confusion assessment method for the intensive care unit (CAM-ICU).

CONTEXT: Delirium is a common problem in the intensive care unit (ICU). Accurate diagnosis is limited by the difficulty of communicating with mechanically ventilated patients and by lack of a validated delirium instrument for use in the ICU. OBJECTIVES: To validate a delirium assessment instrument that uses standardized nonverbal assessments for mechanically ventilated patients and to determine the occurrence rate of delirium in such patients. DESIGN AND SETTING: Prospective cohort study testing the Confusion Assessment Method for ICU Patients (CAM-ICU) in the adult medical and coronary ICUs of a US university-based medical center. PARTICIPANTS: A total of 111 consecutive patients who were mechanically ventilated were enrolled from February 1, 2000, to July 15, 2000, of whom 96 (86.5%) were evaluable for the development of delirium and 15 (13.5%) were excluded because they remained comatose throughout the investigation. MAIN OUTCOME MEASURES: Occurrence rate of delirium and sensitivity, specificity, and interrater reliability of delirium assessments using the CAM-ICU, made daily by 2 critical care study nurses, compared with assessments by delirium experts using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria. RESULTS: A total of 471 daily paired evaluations were completed. Compared with the reference standard for diagnosing delirium, 2 study nurses using the CAM-ICU had sensitivities of 100% and 93%, specificities of 98% and 100%, and high interrater reliability (kappa = 0.96; 95% confidence interval, 0.92-0.99). Interrater reliability measures across subgroup comparisons showed kappa values of 0.92 for those aged 65 years or older, 0.99 for those with suspected dementia, or 0.94 for those with Acute Physiology and Chronic Health Evaluation II scores at or above the median value of 23 (all P<.001). Comparing sensitivity and specificity between patient subgroups according to age, suspected dementia, or severity of illness showed no significant differences. The mean (SD) CAM-ICU administration time was 2 (1) minutes. Reference standard diagnoses of delirium, stupor, and coma occurred in 25.2%, 21.3%, and 28.5% of all observations, respectively. Delirium occurred in 80 (83.3%) patients during their ICU stay for a mean (SD) of 2.4 (1.6) days. Delirium was even present in 39.5% of alert or easily aroused patient observations by the reference standard and persisted in 10.4% of patients at hospital discharge. CONCLUSIONS: Delirium, a complication not currently monitored in the ICU setting, is extremely common in mechanically ventilated patients. The CAM-ICU appears to be rapid, valid, and reliable for diagnosing delirium in the ICU setting and may be a useful instrument for both clinical and research purposes.

APACHE↗

The impact of delirium in the intensive care unit on hospital length of stay.

STUDY OBJECTIVE: To determine the relationship between delirium in the intensive care unit (ICU) and outcomes including length of stay in the hospital. DESIGN: A prospective cohort study. SETTING: The adult medical ICU of a tertiary care, university-based medical center. PARTICIPANTS: The study population consisted of 48 patients admitted to the ICU, 24 of whom received mechanical ventilation. MEASUREMENTS: All patients were evaluated for the development and persistence of delirium on a daily basis by a geriatric or psychiatric specialist with expertise in delirium assessment using the Diagnostic Statistical Manual IV (DSM-IV) criteria of the American Psychiatric Association, the reference standard for delirium ratings. Primary outcomes measured were length of stay in the ICU and hospital. RESULTS: The mean onset of delirium was 2.6 days (S.D.+/-1.7), and the mean duration was 3.4+/-1.9 days. Of the 48 patients, 39 (81.3%) developed delirium, and of these 29 (60.4%) developed the complication while still in the ICU. The duration of delirium was associated with length of stay in the ICU ( r=0.65, P=0.0001) and in the hospital ( r=0.68, P<0.0001). Using multivariate analysis, delirium was the strongest predictor of length of stay in the hospital ( P=0.006) even after adjusting for severity of illness, age, gender, race, and days of benzodiazepine and narcotic drug administration. CONCLUSIONS: In this patient cohort, the majority of patients developed delirium in the ICU, and delirium was the strongest independent determinant of length of stay in the hospital. Further study and monitoring of delirium in the ICU and the risk factors for its development are warranted.

Delirium↗