Search PubMed⌕ Search

Biomedical subjects

L Stern

Publications and source records attributed to L Stern.

At least 19 recordsLinked to original sources
PubMed2005

[DiGeorge syndrome, a review of 52 patients].

UNLABELLED: The deletion of chromosome 22q11.2 is involved in the majority of DiGeorge or velo-cardiofacial syndrome. The phenotypic variability was noted in the "CATCH 22" acronym. This acronym doesn't recapitulate the full spectrum of the symptoms. The diagnosis of this syndrome can be done with the prenatal diagnosis, with fetal pathology or with a child alive. METHODS: Review of 52 cases with the microdeletion 22q11. Six cases were diagnosed during the prenatal period, 12 cases at fetal pathology examination, and 34 cases during infancy. RESULTS: Cardiac malformations were the major indications (75%) to search for the microdeletion. The facial dysmorphy was difficult to diagnose during the antenatal period or in dead foetus, thereby it was not often recognized. The renal anomalies usually present in 35% of cases, were diagnosed in only 6 to 16% of the cases in our study. CONCLUSION: Phenotypic diversity of the DiGeorge syndrome is important. Its knowledge allows to better determine the indications of the research of the microdeletion. 22q11.2.

Child↗
PubMed2004

A rapid method for illustrating features in both coding and non-coding regions of a genome.

A bitmap display of the Fourier spectra has been developed which allows convenient whole chromosome scanning for genes and other features. Use of a limited sliding window gives rapid visualization and localization of coding regions in the chromosomes, as well as non-coding features such as repetitive DNA. The method works particularly well on organisms with a skewed base composition, to provide an overview of genomic features.

Algorithms↗
PubMed2001

Discovering patterns in Plasmodium falciparum genomic DNA.

A method has been developed for discovering patterns in DNA sequences. Loosely based on the well-known Lempel Ziv model for text compression, the model detects repeated sequences in DNA. The repeats can be forward or inverted, and they need not be exact. The method is particularly useful for detecting distantly related sequences, and for finding patterns in sequences of biased nucleotide composition, where spurious patterns are often observed because the bias leads to coincidental nucleotide matches. We show here the utility of the method by applying it to genomic sequences of Plasmodium falciparum. A single scan of chromosomes 2 and 3 of P. falciparum, using our method and no other a priori information about the sequences, reveals regions of low complexity in both telomeric and central regions, long repeats in the subtelomeric regions, and shorter repeat areas in dense coding regions. Application of the method to a recently sequenced contig of chromosome 10 that has a particularly biased base composition detects a long internal repeat more readily than does the conventional dot matrix plot. Space requirements are linear, so the method can be used on large sequences. The observed repeat patterns may be related to large-scale chromosomal organization and control of gene expression. The method has general application in detecting patterns of potential interest in newly sequenced genomic material.

Algorithms↗
PubMed2000

Sequence complexity for biological sequence analysis.

A new statistical model for DNA considers a sequence to be a mixture of regions with little structure and regions that are approximate repeats of other subsequences, i.e. instances of repeats do not need to match each other exactly. Both forward- and reverse-complementary repeats are allowed. The model has a small number of parameters which are fitted to the data. In general there are many explanations for a given sequence and how to compute the total probability of the data given the model is shown. Computer algorithms are described for these tasks. The model can be used to compute the information content of a sequence, either in total or base by base. This amounts to looking at sequences from a data-compression point of view and it is argued that this is a good way to tackle intelligent sequence analysis in general.

Algorithms↗
PubMed1999

Automated outbreak detection: a quantitative retrospective analysis.

An automated early warning system has been developed and used for detecting clusters of human infection with enteric pathogens. The method used requires no specific disease modelling, and has the potential for extension to other epidemiological applications. A compound smoothing technique is used to determine baseline 'normal' incidence of disease from past data, and a warning threshold for current data is produced by combining a statistically determined increment from the baseline with a fixed minimum threshold. A retrospective study of salmonella infections over 3 years has been conducted. Over this period, the automated system achieved > 90% sensitivity, with a positive predictive value consistently > 50%, demonstrating the effectiveness of the combination of statistical and heuristic methods for cluster detection. We suggest that quantitative measurements are of considerable utility in evaluating the performance of such systems.

Australia↗
PubMed1999

Aminophylline increases seizure length during electroconvulsive therapy.

Electroconvulsive therapy (ECT) is considered to be one of the most effective treatments for patients with major depression and persistent psychosis. Seizure characteristics probably determine the therapeutic effect of ECT; as a consequence, short seizures are accepted as one of the factors of poor outcome. During most ECT courses seizure threshold increases and seizure duration decreases. Methylxanthine preparations, caffeine, and theophylline have been used to prolong seizure duration. The use of aminophylline, more readily available than caffeine, has not been well documented. The objective of this study was to test the effects of aminophylline on seizure length. Fourteen drug-free patients with diagnoses of affective disorder or psychotic episode receiving ECT participated in this study. Seizure length was assessed clinically and per EEG. Statistical comparisons were done using paired t tests. A significant increase (p < 0.04) in seizure length was achieved and maintained on three subsequent treatments with aminophylline. No adverse events were noted from the addition of aminophylline.

Adult↗
PubMed1998

Treatment of severe, drug resistant obsessive compulsive disorder with the 5HT1D agonist sumatriptan.

The serotonergic system has been implicated in both the aetiology and pharmacological treatment of obsessive compulsive disorder. In pharmacological challenge tests, mCPP, a 5-HT agonist, with an affinity for 5HT2C as well as 5HT1A and 5HT1D receptors, was associated with a transient exacerbation of obsessive compulsive symptoms. Chronic administration of mCPP was found to bring about some relief of these symptoms. Sumatriptan is an antimigraine agent, which interacts most potently with 5HT1D receptors. In the cases to be presented, we report the effects of chronic administration of Sumatriptan to three severe, treatment resistant, OCD patients. Following chronic administration of sumatriptan, these patients, who have been resistant to any former pharmacological treatment, responded with an improvement in their depression and a modest reduction in their obsessive compulsive symptoms.

Adult↗
PubMed1998

Effect of 5% albumin solution on sodium balance and blood volume after subarachnoid hemorrhage.

OBJECTIVE: Subarachnoid hemorrhage (SAH) predisposes patients to excessive natriuresis and volume contraction. We studied the effects of postoperative administration of 5% albumin solution on sodium balance and blood volume after SAH. We also sought to identify physiological variables that influence renal sodium excretion after SAH. METHODS: Forty-three patients with acute SAH were randomly assigned to receive hypervolemia or normovolemia treatment for a period of 7 days after aneurysm clipping. In addition to a base line infusion of normal saline solution (80 ml/hr), 250 ml of 5% albumin solution was administered every 2 hours for central venous pressure (CVP) values of < or =8 mm Hg (hypervolemia group, n = 19) or < or =5 mm Hg (normovolemia group, n = 24). RESULTS: Both groups demonstrated relative volume expansion in base line measurements. The hypervolemia group received significantly more total fluid, sodium, and 5% albumin solution than did the normovolemia group and had higher CVP values and serum albumin levels (all P < 0.02). Cumulative sodium balance was even in the hypervolemia group and persistently negative in the normovolemia group, because of sodium losses that occurred on Postoperative Days 2 and 3 (P = 0.03). In a multiple-regression analysis of all patients, 24-hour sodium balance correlated negatively with glomerular filtration rate (GFR) and positively with serum albumin levels, after correction for sodium intake (P < 0.0001). Hypervolemia therapy seemed to paradoxically lower GFR (P = 0.10) and had no effect on blood volume, which declined by 10% in both groups. Pulmonary edema requiring diuresis occurred in only one patient in the hypervolemia group. CONCLUSION: Supplemental 5% albumin solution given to maintain CVP values of >8 mm Hg prevented sodium and fluid losses but did not have an impact on blood volume in our patients, who were hypervolemic in base line measurements. The natriuresis that occurs after SAH may be mediated in part by elevations of GFR. In addition to acting as a colloid volume expander, 5% albumin solution lowers the GFR and promotes renal sodium retention after SAH. These properties may limit the amount of total fluid required to maintain a given CVP value and hence may minimize the frequency of pulmonary edema.

Adult↗
PubMed1997

ECT in patients with major depressive disorder and low cardiac output.

Electroconvulsive therapy (ECT) in patients with impaired cardiac output may be associated with significant cardiovascular morbidity and mortality because of its hemodynamic effects. Many clinicians are reluctant to treat these patients with ECT because of the high risk associated with the treatment. In this report, we present a clinically appropriate protocol for ECT treatment of patients with impaired cardiac output and major depressive disorder. Three patients, ages 59-78 years, with resistant major depression and impaired cardiac output (ejection fraction 20-25%), were successfully treated with ECT according to this protocol.

Aged↗
PubMed1996

Low prevalence of human papillomavirus infection of the cervix in renal transplant recipients.

BACKGROUND: An increased risk of anogenital tract malignancies has been noted among renal transplant recipients. A high prevalence of human papillomavirus (HPV) infection of the cervix in the female renal-transplant population has been assumed based on increasing evidence suggesting that HPV infection is the major risk factor for cervical intraepithelial neoplasia (CIN) and cervical cancer. It has been assumed that immunosuppression leads to either a reactivation of latent HPV or a reduction in the host's ability to contain a primary HPV infection, thereby increasing the risk of CIN and cervical cancer. The objective of this study was to evaluate the prevalence of human papillomavirus (HPV) infection in a population of iatrogenically immunosuppressed renal transplant recipients. METHODS: Twenty-one women were recruited from the renal transplant clinic at Presbyterian Hospital and underwent a gynaecological examination which included colposcopy, a Papanicolaou smear, and a cervicovaginal lavage. Lavage samples were analysed for HPV DNA using L1 consensus primers and the polymerase chain reaction (PCR). RESULTS: No cases of cervical intraepithelial neoplasia (CIN) were detected in this cohort of 21 immuno-suppressed renal transplant recipients. HPV DNA was detected in only a single patient. CONCLUSIONS: Our data suggests that HPV infection is not highly prevalent among older, cytologically normal renal transplant recipients, particularly those who are currently monogamous or not presently sexually active. This study suggests that recent sexual behaviours are more important than past behaviours as a determinant of HPV status in transplant recipients, and also suggests that education concerning the avoidance of high-risk sexual behaviour is an important part of the care of the female renal transplant recipient. Our data is consistent with previous work suggesting that the incidence of CIN is declining in transplant recipients, and it also suggests that the prevalence of HPV infection may be declining as well.

Adult↗
PubMed1995

IL-2 and IL-6 secretion in dementia: correlation with type and severity of disease.

The production of interleukin-2 (IL-2) and interleukin-6 (IL-6) by peripheral blood mononuclear cells (MNC) was assessed in patients with Alzheimer's disease (AD) who were subdivided into two groups--mild and moderately-severe--according to the severity of the disease, probable vascular dementia (VaD) patients and elderly control subjects. No differences in IL-2 secretion were found between mild AD patients and controls. However, there was a significant increase in IL-2 production both in the moderately-severe AD group and in the VaD group. IL-6 levels in AD patients of both groups were similar and significantly higher than those of VaD and controls. Our results suggest that increased levels of IL-2-production correlate with severity of the dementia, whereas increased levels of IL-6 production seem to be related to AD and thus may play a role in AD pathogenesis.

Aged↗
PubMed1994

Elevated interleukin-6 secretion levels by mononuclear cells of Alzheimer's patients.

It has been suggested in recent research that interleukin-1 (IL-1) and interleukin-6 (IL-6) play a role in the pathogenesis of Alzheimer's disease (AD). Production of IL-1, by lipopolysaccharide (LPS)-stimulated monocytes, and IL-6, by phytohaemagglutinin (PHA)-stimulated mononuclear cells, was assessed in patients with AD divided into two groups--mild and moderately severe--according to severity of disease, and elderly controls. No differences in IL-1 production were found among AD patients and controls. However, significant elevation in IL-6 secretion levels was observed in both the mild and moderately severe AD patients. Our results suggest that peripheral IL-6 secretion levels may be responsible for acute-phase proteins observed in the serum of AD patients.

Aged↗
PubMed1993

The epidemiology of peritonitis in acute peritoneal dialysis: a comparison between open- and closed-drainage systems.

We performed a prospective study to examine the epidemiology and microbiology of peritonitis complicating acute intermittent peritoneal dialysis (IPD) performed in an in-hospital setting for the management of acute and chronic renal failure and to see the effect of a closed-drainage system on altering the frequency and cause of peritonitis. Over a 15-month period, 79 patients were treated with acute IPD for a total of 136 treatments each ranging in length from 2 to 40 days (median, 4 days). The majority of cases had acute renal failure (ARF; 65%) and were treated in intensive care units (ICUs; 74%) with serious comorbid conditions (60%). About half were treated with a two-bag, ventable (open)-drainage system with unprotected spikes, and the other half were treated with a single-bag, spike-protected, closed-drainage system. There were 27 cases of peritonitis for a rate of 4.5 cases/100 patient-days at risk. About half were gram-positive infections; the remainder were gram-negative or mixed (25%) or Candida sp (25%). The use of a closed-drainage system reduced the incidence of system-related peritonitis from 3.6 to 1.5 cases/100 patient-days. There was a high rate of peritonitis in the first 48 hours of treatment, which fell to a low stable rate thereafter and remained so for up to 15 days of continuous IPD. The use of a closed-drainage system eliminated the early (< 48 hours) high rate of peritonitis and maintained a low constant rate of peritonitis throughout treatment. There was an association of ARF and severe comorbid disease with more virulent organisms (gram-negative, mixed, and Candida sp), which, in turn, were both associated with antecedent broad-spectrum antibiotic therapy. Random positive surveillance cultures showed a frequency distribution similar to that of peritonitis cases over the duration of treatment, but with less virulent organisms. Peritonitis in acute IPD occurs when large or repeated inocula of organisms from the prevailing flora overwhelm the peritoneal immune clearance mechanisms. Prolonged courses of broad-spectrum antibiotic therapy provide no protection, but shift the resulting infecting flora toward more virulent pathogens. A closed-drainage system provides one method to reduce the frequency of peritoneal contamination.

Adolescent↗