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Biomedical subjects

K E Chandler

Publications and source records attributed to K E Chandler.

18 recordsLinked to original sources
PubMed2006

Regulation and role of REST and REST4 variants in modulation of gene expression in in vivo and in vitro in epilepsy models.

Repressor element-1 silencing transcription factor (REST) is a candidate modulator of gene expression during status epilepticus in the rodent. In such models, full-length REST and the truncated REST4 variant are induced and can potentially direct differential gene expression patterns. We have addressed the regulation of these REST variants in rodent hippocampal seizure models and correlated this with expression of the proconvulsant, substance P encoding, PPT-A gene. REST and REST4 were differentially regulated following kainic acid stimulus both in in vitro and in vivo models. REST4 was more tightly regulated than REST in both models and its transient expression correlated with that of the differential regulation of PPT-A. Consistent with this, overexpression of a truncated REST protein (HZ4, lacking the C-terminal repression domain) increased expression of the endogenous PPT-A gene. Similarly the proximal PPT-A promoter reporter gene construct was differentially regulated by the distinct REST isoforms in hippocampal cells with HZ4 being the major inducer of increased reporter expression. Furthermore, REST and REST4 proteins were differentially expressed and compartmentalized within rat hippocampal cells in vitro following noxious stimuli. This differential localization of the REST isoforms was confirmed in the CA1 region following perforant path and kainic acid induction of status epilepticus in vivo. We propose that the interplay between REST and REST4 alter the expression of proconvulsant genes, as exemplified by the PPT-A gene, and may therefore regulate the progression of epileptogenesis.

Animals↗
PubMed2005

Leucodysplasia, microcephaly, cerebral malformation (LMC): a novel recessive disorder linked to 2p16.

We report three related and one unrelated child with an apparently novel neurodevelopmental disorder. The clinical course was very similar in all the four patients: congenital microcephaly with severe failure of post-natal brain growth, neonatal onset of intractable seizures associated with lack of developmental progression and death within the first 3 years of life. The appearance on cerebral neuroimaging was almost identical, with simplified gyration associated with a non-thickened cortex, severe hypoplasia of the corpus callosum, a small flattened brain stem, and specific cystic lesions in the white matter around the temporal and occipital horns. To our knowledge these patients represent a previously unreported, autosomal recessive syndrome. Homozygosity mapping in the consanguineous family has identified a candidate region on the chromosome 2p16.

Abnormalities, Multiple↗
PubMed2003

Neuropsychological assessment of a group of UK patients with Cohen syndrome.

Cohen syndrome is a rare autosomal recessive syndrome with a distinctive clinical phenotype that includes mental retardation and a characteristic sociable disposition. Variability in the level of learning disability and the behavioural phenotype is seen in the published literature. In a cohort of Finnish Cohen syndrome patients, severe mental retardation and non-maladaptive behaviour were described. Outside of Finland, autistic-spectrum behaviour has been reported in a few isolated Cohen syndrome patients but in a recent UK study was found to be highly prevalent. We report the results of neuropsychological studies in a group of 16 genetically heterogeneous patients, all with the characteristic clinical features of Cohen syndrome. Of the 9 patients who underwent formal neuropsychological testing, all but one was functioning in the severely mentally impaired range. Of the remaining patients, 3 were below the age of formal testing and 4 had such profound learning and behavioural problems that they were deemed unable to participate in testing. Mild maladaptive behaviour was observed in 13 patients and 3 were documented as having significant maladaptive behaviour. In contrast to the Finnish group of Cohen syndrome patients, this UK study identifies significant neuropsychological impairment combined with maladaptive behaviour as a characteristic of Cohen syndrome. Although autistic-type behaviour was observed, an increased prevalence of autism in Cohen syndrome was not confirmed.

Adolescent↗
PubMed2003

Diagnostic criteria, clinical characteristics, and natural history of Cohen syndrome.

Cohen syndrome is a rare, recessively inherited condition associated with facial dysmorphism, developmental delay, and visual disability. A delay in making the diagnosis commonly occurs, contributed to by the lack of a definitive molecular test and the clinical variability of published case reports. A specific clinical phenotype has been delineated in a homogeneous cohort of Finnish Cohen syndrome patients, but the applicability of their diagnostic criteria to non-Finnish patients has been debated. Detailed delineation of Cohen syndrome in patients from outside Finland is therefore warranted. We report on the clinical features of 33 non-Finnish Cohen syndrome patients. Variability within the clinical spectrum is identified and the natural history of Cohen syndrome described. Diagnostic guidelines for facilitating accurate and early diagnosis are discussed. Results from molecular genetic analysis using markers located within the previously mapped COH1 critical region support allelic but not genetic heterogeneity in this UK cohort.

Abnormalities, Multiple↗
PubMed2002

The ophthalmic findings in Cohen syndrome.

AIM: Cohen syndrome is an uncommon autosomal recessive condition comprising a characteristic facial appearance, mental retardation, benign neutropenia, and retinal dystrophy. This study aimed to identify patients with Cohen syndrome from across the United Kingdom in order to define the variability of ophthalmic manifestations. METHODS: Ophthalmic assessment was undertaken and past ophthalmic records reviewed in 22 patients with classic features of Cohen syndrome. RESULTS: All patients had visual problems which commonly started in the preschool years. 82% developed strabismus or refractive error during the first 5 years of life. 70% developed high myopia by the second decade. By contrast with the findings of others, early onset retinal dystrophy was common, occurring in 80% of study patients under age 5 years. 35% of patients were registered partially sighted or blind. CONCLUSION: The ophthalmic abnormalities associated with Cohen syndrome, including high myopia and a generalised, severe retinal dystrophy, are of early onset and frequently result in severe visual handicap. Cohen syndrome should be considered in the young, developmentally delayed child who presents with severe myopia and nyctalopia.

Adolescent↗
PubMed1998

Age and causes of death in adult-onset myotonic dystrophy.

Myotonic dystrophy is a relatively common type of muscular dystrophy, associated with a variety of systemic complications. Long term follow-up is difficult because of the slow progression. The objective of this study was to determine survival, age at death and causes of death in patients with the adult-onset type of myotonic dystrophy. A register of myotonic dystrophy patients was set up in Southern Limburg (the Netherlands), using data longitudinally collected over a 47-year period (1950-97). Survival for 180 patients (from the register) with adult-onset type myotonic dystrophy was established by the Kaplan-Meier method. The median survival was 60 years for males and 59 years for females. Survival of the patients was also estimated from the age of 15 years to the ages of 25, 45 and 65 years and compared with the expected survival of age- and sex-matched birth cohorts from the normal Dutch population. The observed survival to the ages of 25, 45 and 65 years was 99%, 88% and 18% compared with an expected survival of 99%, 95% and 78%, respectively. Thus, survival to the age of 65 in patients with adult-onset myotonic dystrophy is markedly reduced. A weak positive correlation between the CTG repeat length and younger age at death was found in the 13 patients studied (r = 0.50, P = 0.08). The cause of death could be determined in 70 of the 83 deceased patients. Pneumonia and cardiac arrhythmias were the most frequent primary causes of death, each occurring in approximately 30%, which was far more than expected for the general Dutch population. In addition, we assessed mobility in the years before death in a subgroup of 18 patients, as a reflection of the long-term physical handicap in myotonic dystrophy patients. Half of the patients studied were either partially or totally wheelchair-bound shortly before their death.

Age Distribution↗
PubMed1997

Severe feeding problems and congenital laryngostenosis in a patient with 3q23 deletion.

UNLABELLED: Common clinical features of patients with 3q23 deletion include the phenotype of BPES (blepharophimosis, ptosis, epicanthus inversus and telecanthus syndrome), growth and mental retardation, microcephaly ear and nose dysmorphism and joint and digit abnormalities. We report on a 3-year-old girl with the phenotype of BPES, mental retardation, facial dysmorphism and camptodactyly. In addition, she had a congenitally small larynx and severe, chronic feeding difficulties. Chromosome studies revealed an interstitial deletion in the long arm of chromosome 3: del(3)(q23-q25). CONCLUSION: Congenital laryngostenosis and severe feeding problems may be part of the clinical syndrome caused by chromosome 3q23 deletion.

Abnormalities, Multiple↗
PubMed1994

Laparoscopic cholecystectomy in biliary pancreatitis.

Laparoscopic cholecystectomy has emerged as the treatment of choice for uncomplicated cholelithiasis. Despite early concerns, many surgeons have applied this new technique to more complicated biliary tract disease states, including biliary pancreatitis. To evaluate the safety of laparoscopic cholecystectomy in this setting, we retrospectively reviewed 29 patients with clinical and laboratory evidence of biliary pancreatitis who underwent this procedure between March 1990 and December 1992. The severity of pancreatitis was determined by Ranson's criteria. Two patients had a Ranson's score of 6, one of 5, one of 4, five scored 3, nine scored 2, nine also scored 1, and two patients scored 0. The mean serum amylase level on admission was 1,610 (range 148 to 7680). All patients underwent laparoscopic cholecystectomy during the same hospital admission for biliary pancreatitis, with the mean time of operation being 5.5 days from admission. Operative time averaged 123 minutes (range 60-220 minutes). Intraoperative cholangiography was obtained in 76 per cent of patients. Three patients had choledocholithiasis on intraoperative cholangiography and were treated with choledochoscopy, laparoscopic common bile duct exploration, and saline flushing of the duct. The mean length of hospital stay was 11 days (range 5-32 days). There were seven postoperative complications requiring prolonged hospitalization with all but one treated non-operatively. One patient with a preoperative Ranson score of 6 developed necrotizing pancreatitis and subsequently required operative pancreatic debridement and drainage. There were no deaths in this series and no postoperative wound infections. The average recovery period for return to work was 2 weeks. These statistics compare favorably with literature reports for open cholecystectomy in biliary pancreatitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Video thoracoscopic dorsal sympathectomy: a new approach.

With the recent popularization of video laparoscopic cholecystectomy comes a renewed interest in thoracoscopy and its clinical applications in intrathoracic disease. Successful video thoracoscopic dorsal sympathectomy was accomplished in a patient with causalgia of the right upper extremity with immediate and complete resolution of pain and vasomotor symptoms. Standard operative approaches to dorsal sympathectomy are technically difficult, having risks of major nerve injury and Horner's syndrome. Video thoracoscopic dorsal sympathectomy obviates these risks and should become the procedure of choice in the future.

Adult↗
PubMed1993

Laparoscopic hernia repair: a preliminary report.

Advances in laparoscopic technique have provided the opportunity to perform preperitoneal herniorrhaphy and potentially avoid the morbidity associated with open techniques. From January 1991 to May 1992, two primary surgeons repaired 63 inguinal hernias (42 indirect, 20 direct, 1 femoral) on 48 patients using a standardized laparoscopic technique. The hernia defect was visualized laparoscopically, and the peritoneum anterior to the defect was incised. The hernia sac was dissected from the inguinal canal. The hernia defect was then loosely packed with rolled 1 x 6-inch polypropylene mesh (average number of rolls used was 3.4). A sheet of polypropylene mesh (average 5 x 8 cm) was then placed over the mesh rolls and the hernia defect and anchored with an endostapler. The peritoneum was closed over the mesh sheet with standard laparoscopic clips. There were 44 males and 4 females in the study group. The mean age was 55 years (range, 17-89 years). The mean follow-up was 5.8 months (range, 1-12 months). Thirty-three patients underwent unilateral hernia repair, and 15 patients underwent bilateral hernia repair. Clinically unsuspected contralateral hernias were identified at the time of laparoscopy in seven patients. The mean duration of surgery was 118 minutes (range, 80-165 minutes) for bilateral hernia repair, and 70 minutes (range, 45-100 minutes) for unilateral hernia repair. All patients with laparoscopic hernia repairs were treated on a same-day or less-than-24-hour in-hospital stay. Complications were designated as minor, moderate, or severe. There were 14 minor complications, which included subcutaneous hematomas at the trocar site, scrotal ecchymosis, groin swelling emphysema, and testicular asymmetry.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1993

Laparoscopic inguinal herniorrhaphy in a swine model. Third place winner of the Conrad Jobst Award in the Gold Medal paper competition.

A simplified method of laparoscopic inguinal herniorrhaphy using prosthetic materials was evaluated in a swine hernia model. The goals of this study were to determine 1) effectiveness of repair in a rapidly growing animal, 2) effectiveness and extent of adhesion formation of different prosthetic materials, 3) the effect of repair on testicular growth, and 4) histologic effects on the hernia site and surrounding structures. In a prospective randomized study, 30 juvenile male swine (average, 23 kg) with 35 congenital indirect inguinal hernias underwent laparoscopic herniorrhaphy using one of three prosthetic materials: Group 1 (polytetrafluoroethylene/Gore-Tex), N = 10; Group 2 (polypropylene mesh/Marlex), N = 10; Group 3 (polypropylene mesh/Prolene), N = 10. A standardized laparoscopic herniorrhaphy technique consisting of stapling prosthetic material over the hernia defect without peritoneal dissection was employed. During the 3-month postoperative period, animals were sequentially examined for normal growth and development, normal testicular development, and signs of hernia recurrence. Clinically apparent complications related to herniorrhaphy occurred in five animals (17%) during the observation period (one with repair failure, one with testicular torsion, two with repair failure and bowel obstruction, and one with intestinal obstruction secondary to adhesions). All three animals with bowel obstruction died. At 90 days after surgery all remaining animals (N = 27) were euthanized (Group 1 = 9, Group 2 = 8, Group 3 = 10). Average weight was 84 kg. Necropsy findings included no additional hernia recurrences, and one mesh erosion into the urinary bladder.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Safety, efficacy, cost, and morbidity of laparoscopic versus open cholecystectomy: a prospective analysis of 228 consecutive patients.

Laparoscopic cholecystectomy has become the procedure of choice in most hospitals for the resolution of surgically treatable gallbladder disease. Few reports address the results of laparoscopic cholecystectomy in comparison to open cholecystectomy during the same time interval within the same institution. One hundred ninety-six laparoscopic cholecystectomies were performed from April 1990 through February 1991. Initial patient selection was restricted to elective procedures for chronic cholecystitis with expanded indications as experience was gained. Of the 196 cases, 11 required conversion to open cholecystectomy, leaving 185 laparoscopic cholecystectomies for comparison. During the same period, 82 open cholecystectomies were performed. Thirty-nine of these were complicated cases and would not have been considered for laparoscopic cholecystectomy early in the study, leaving 43 routine open cholecystectomies for comparative purposes. In the laparoscopic group, 1.1 per cent of the patients had major operative complications as opposed to the open group, which had none. There were no common bile duct injuries in either group. To provide a true cost-benefit analysis, a group of patients was identified that would qualify for elective, same-day admission for either an open or laparoscopic procedure. Laparoscopic cholecystectomy (LC) was performed on 70 patients, and open cholecystectomy (OC) was performed on 26 patients. A comparison of data from these groups showed no significant difference in age or sex. Hospitalization costs averaged $5,390 for the LC group versus $5,392 for the OC group. Postoperative hospital stay averaged 1.3 days for the LC group versus 3.7 days for the OC group (P < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Cholangiography↗
PubMed1976

Ruptured submucosal gastric artery microaneurysm.

A patient with massive upper gastrointestinal hemorrhage from a ruptured submucosal gastric artery microaneurysm is described. Intraoperative diagnosis was made and wedge resection of the lesion resulted in survival of the patient. Forty-two cases in this entity have been reported in the literature, with nonoperative therapy being uniformly fatal; there were only four cases of successful surgical management. An increased awareness of this entity in cases of unexplained gastrointestinal hemorrhage is the key to diagnosis and successful management.

Aged↗