GJ 367b: A dense, ultrashort-period sub-Earth planet transiting a nearby red dwarf star

[Figure: see text].

Influence of nesting shell size on brightness longevity and resistance to ultrasound-induced dissolution during enhanced B-mode contrast imaging

This study aims to bridge the gap between transport mechanisms of an improved ultrasound contrast agent (UCA) and its resulting behavior in a clinical imaging study. Phospholipid-shelled microbubbles nested within the aqueous core of a polymer microcapsule are examined for their use and feasibility as an improved UCA. The nested formulation provides contrast comparable to traditional formulations, specifically an SF6 microbubble coated by a DSPC PEG-3000 monolayer, with the advantage that contrast persists at least nine times longer in a mock clinical, in vitro setting. The effectiveness of the sample was measured using a contrast ratio in units of decibels (dB) which compares the brightness of the nested microbubbles to a reference value of a phantom tissue mimic. During a 40min imaging study, six nesting formulations with average outer capsule diameters of 1.95, 2.53, 5.55, 9.95, 14.95, and 20.51μm reached final contrast ratio values of 0.25, 2.35, 3.68, 4.51, 5.93, and 8.00dB, respectively. The starting contrast ratio in each case was approximately 8dB and accounts for the brightness attributed to the nesting shell. As compared with empty microcapsules (no microbubbles nested within), enhancement of the initial contrast ratio increased systematically with decreasing microcapsule size. The time required to reach a steady state in the temporal contrast ratio profile also varied with microcapsule diameter and was found to be 420s for each of the four smallest shell diameters and 210s and 150s, respectively, for the largest two shell diameters. All nested formulations were longer-lived and gave higher final contrast ratios than a control sample comprising un-nested, but otherwise equivalent, microbubbles. Specifically, the contrast ratio of the un-nested microbubbles decreased to a negative value after 4min of continuous ultrasound exposure with complete disappearance of the microbubbles after 15min whereas all nested formulations maintained positive contrast ratio values for the duration of the 40min trial. The results are consistent with two distinct stages of gas transport: in the first stage, passive diffusion occurs under ambient conditions across the microbubble monolayer within the first few minutes after formulation until the aqueous interior of the microcapsule is saturated with gas; in the second stage ultrasound drives additional gas dissolution even further due to pressure modulation. It is important to understand the chemistry and transport mechanisms of this contrast agent under the influence of ultrasound to attain better perspicacity for enhanced applications in imaging. Results from this study will facilitate future preclinical studies and clinical applications of nested microbubbles for therapeutic and diagnostic imaging.

Comparative study of changes in arterial pressure and heart rate during dental treatment under local anesthesia in hypertensive patients versus normotensive patients

The aim of this study was to determine changes in arterial pressure (AP) and heart rate (HR) during dental treatment under local infiltration anesthesia (LIA) in patients with controlled arterial hypertension (AHT) versus normotensive patients. A longitudinal comparative study involving repeated measurements in well-controlled hypertensive (cases) and normotensive patients (controls) was conducted. All patients received standardized preventive periodontal treatment under LIA (1.8 ml of 4% articaine with 1:100000 L-Adrenaline). AP and HR were determined at 5 different phases of treatment. The study comprised 82 patients, 46.3% of whom were hypertensive, 61% were female. Systolic (SAP) and diastolic (DAP) arterial pressure and HR increased as the procedure advanced and then returned to initial values in both groups. Average HR values were lower in normotensive than in hypertensive patients (p < 0.001). Significant differences in AP and HR were observed among initial, mid-procedure, and final values (p < 0.001). Both groups exhibited highest SAP values post-LIA administration (p < 0.01). Average HR was higher in normotensive than in hypertensive patients. The hypertensive patients tended to develop AHT (> 140/90 mmHg) more frequently throughout the procedure (p = 0.002), SHOWING a 4.93-fold higher risk. Logistic regression analysis showed that sex (p < 0.032) and AH (p < 0.007) were associated with a tendency to develop AHT during treatment. Controlled hypertensive patients with normal AP values at the onset of dental treatment were found to be at a 5-fold higher risk of developing AHT during the course of dental treatment under local infiltration anesthesia. The observed increases in AP, however, did not reach clinically significant levels. The HR values tended to increase with the progress of dental treatment in all patients. HR was lower in hypertensive patients probably due a drug effect.

Hyperechogenic fetal bowel: a large French collaborative study of 682 cases

Hyperechogenic fetal bowel is detected in 0.1-1.8% of pregnancies during the second or third trimester. This ultrasound sign is associated with cystic fibrosis or other conditions (e.g., chromosomal anomalies, viral infection) but no large-scale prospective studies have been conducted. This 1997-1998 multicenter study in 22 molecular biology laboratories identified 682 cases of hyperechogenic fetal bowel detected by routine ultrasound examination during the second (86%) or third trimester. The fetal bowel was considered hyperechogenic when its echogenicity was broadly similar to, or greater than, that of the surrounding bone. Karyotyping, screening for viral infection, and screening for cystic fibrosis mutations were performed in all cases. Pregnancy outcome and postnatal follow-up were obtained in 656 of the 682 cases (91%). In 447 cases (65.5%), a normal birth was observed. Multiple malformations were observed in 47 cases (6.9%), a significant chromosomal anomaly was noted in 24 (3.5%), cystic fibrosis in 20 (3%), and viral infection in 19 (2.8%). In utero unexplained fetal death occurred in 1.9% of cases, toxemia in 1.2%, IUGR in 4.1%, and premature birth in 6.2%. This study demonstrates that this ultrasound sign is potentially associated with medically significant outcomes. Having established that the bowel is hyperechogenic, recommended investigations should include a detailed scan with Doppler measurements, fetal karyotyping, cystic fibrosis screening, and infectious disease screening. After birth, newborns require pediatric examination because a surgical treatment may be necessary. This should be combined with clear counseling of the parents.

[Importance of recombinant k82 in the diagnosis of latex allergy]

Measurement of IgEs keeps a predominant place in the diagnosis of allergy and in particular in certain pathologies such as those induced by dangerous allergens like, for example, latex. The contribution of recombinant allergens is a significant element in the measurement of IgEs and we have observed this for latex. Sensitivity of recombinant k82 is significantly greater than that of k82. It permits better detection of patients who are sensitised to latex and thus a better prevention by absence of frequent contact with latex gloves and detergents.

[Value of quantitative IgE measurement]

The results of assay of IgE can only be expressed by a very imprecise system of classes. Quantification of the measurement of IgE by the method of the CAP-system of prognosis of allergic patients. Expression of IgE by a measurement of intensity of fluorescence allows the establishment of a decent curve for each allergen. It makes a method of predictive evaluation of risk of the allergy pathology for each allergen. It significantly improves the sensitivity, since it allows detection of IgE at levels less than 0.35 KUA/l. Thus it gives a considerable improvement for the clinician at the level of diagnosis avoiding the "gold standard" provocation test in allergy diagnosis as well at the level of prognosis.

Isolated late-onset cone-rod dystrophy revealing a familial neurogenic muscle weakness, ataxia, and retinitis pigmentosa syndrome with the T8993G mitochondrial mutation

PURPOSE

To report a late-onset cone-rod dystrophy that revealed a familial neurogenic muscle weakness, ataxia, and retinitis pigmentosa syndrome as a consequence of the T8993G mitochondrial mutation.

METHODS

Observational case series. A 42-year-old female disclosed a late-onset retinal dystrophy. The family history revealed that her three sons, one of them deceased at the age of 4, had mental and neurologic impairment of variable severity. The retinal dystrophy of the mother was classified as a cone-rod dystrophy. Retinal dystrophy was subsequently diagnosed in the two surviving sons. Screening for mutation in the mitochondrial DNA (mtDNA) was performed because of the combination of neurologic involvement and retinal dystrophy in this family.

RESULTS

Molecular analysis of the mtDNA revealed the ATPase-6 gene T8993G mutation in the mother and the two sons.

CONCLUSION

This family illustrates the remarkably variable expression of retinal and systemic manifestations related to the T8993G mutation ranging from an isolated late-onset cone-rod dystrophy to a severe neurodegenerative process with a dramatic outcome. Genetic counseling for retinal dystrophies requires careful evaluation of the familial medical history.

Assessment of new markers for the rapid detection of aneuploidies by quantitative fluorescent PCR (QF-PCR)

Rapid prenatal diagnoses of major chromosome aneuploidies have been achieved successfully using quantitative fluoresent PCR (QF-PCR) assays and small tandem repeat (STR) markers. Here we report the results of evaluating the use of previously untested X-linked STRs, (DXS6803) and (DXS6809), together with modified amelogenin (AMXY) sequences and the X22 marker that maps in the pseudoautosomal region PAR2 on the long arm of the X and Y chromosomes. These markers will allow prenatal diagnoses of sex chromosome aneuploidies such as 45,X (pure Turner Syndrome), 47,XXY and 47,XYY, while assessing the sex of the fetuses. Data are also presented concerning the difficulties associated with the evaluation of the frequencies of the various types of sub-populations of cells in amniotic fluid samples collected from fetuses with sex chromosome mosaicism. The results of evaluating the use of new markers for the rapid diagnosis of aneuploidies affecting chromosomes 21,18 and 13 are also presented. Three chromosome 21 specific STRs have been found to produce trisomic triallelic or diallelic patterns from all amniotic samples retrieved from fetuses with Down Syndrome. Since all samples tested were amplified and no false positive or negative results were observed, the present results confirm the diagnostic value of QF-PCR for the prenatal detection of major numerical chromosome disorders.

Serological rebound in congenital toxoplasmosis: long-term follow-up of 133 children

Although serological rebound is common in infants with congenital toxoplasmosis, clinical recommendations for management, in particular the need for additional treatment, vary. The goals of our retrospective cohort study in 133 consecutive children with congenital toxoplasmosis were to estimate the incidence and duration of the rebounds, identify predictive factors, assess the long-term risk of eye lesions and the need for treatment. We first estimated the incidence and duration of rebounds and identified predictive factors using an univariate analysis and a Cox model modified to include time-dependent variables. Two cohort studies were then conducted to compare the incidence density of secondary eye lesions in children who had a rebound versus no rebound, and among children who had a rebound after initial therapy, in those who received an additional course of treatment and in those who did not. Of the 133 children, 93 (70%) had at least one rebound during a mean follow-up of 95 months. Of those with one rebound diagnosed after initial treatment, 33 received an additional 3-month course of pyrimethamine/sulphadoxine and 48 were not treated. Intracranial calcification at birth was associated with an increased relative risk (RR) of rebound (RR = 2.601; P = 0.03), and treatment with pyrimethamine/sulphadoxine between 2 and 12 months of age with a decreased risk (RR = 0.3; P = 0.0845), whereas age of pregnancy at maternal infection, type of treatment during pregnancy and sex were not found to be predictive factors. There was no difference in incidence densities of secondary eye lesions in children without rebound (7/3,367 child-months) compared to those with at least one rebound (22/9,609 child-months) (RR = 1.10; 95% CI: 0.47-2.58), and, among the 81 children who had one rebound diagnosed after initial treatment, in those who received an additional course of treatment and in those who did not (RR = 0.72; 95% CI: 0.30-1.72).

CONCLUSION

serological rebound is common in children with congenital toxoplasmosis but, due to the risk and constraints, an additional course of treatment and more ophthalmological surveillance than currently practiced do not seem warranted.

Connexin 26 gene mutations in congenitally deaf children: pitfalls for genetic counseling

OBJECTIVE

To evaluate difficulties encountered in genetic counseling in deaf children carrying connexin 26 gene (CX26 or GJB2) mutations.

DESIGN

Prospective study.

SETTING

Outpatients, tertiary referral center.

PATIENTS

Ninety-six unrelated deaf children in whom CX26 mutations had been detected consecutively. Children were recruited to a center for genetic counseling for deaf children, and all had congenital deafness, sporadic or familial.

RESULTS

In 63 children, deafness was clearly a DFNB1 form with autosomal recessive inheritance: 47 of the 63 were homozygous for the most frequent mutation, the deletion of G at position 35 (35delG); 16 of 63 carried on both alleles of CX26 frameshift or stop mutations, or missense mutations affecting a critical region of the gene. In 33 of 96 children, genetic counseling was difficult: 21 of 33 had a single mutation detected, 11 of 33 had new missense mutations or mutations whose pathogenicity remains debated in the literature, and 1 of 33 had a genotype with both a recessive mutation (35delG) and a mutation acting as a dominant mutation.

CONCLUSIONS

Interpretation of results for the molecular diagnosis of mutations in the connexin 26 gene is difficult in almost one third of cases. Close collaboration between geneticists familiar with deafness and otolaryngologists is essential to provide a high standard of genetic advice.

Defining the efficiency of fluorescence in situ hybridization on uncultured amniocytes on a retrospective cohort of 27407 prenatal diagnoses

Rapid prenatal detection of selected numerical chromosomal abnormalities by using fluorescence in situ hybridization (FISH) on uncultured amniotic fluid samples was described six years ago. It allows a very rapid identification of selected aneuploidies. We have indexed the results of our 27407 fetal karyotypes obtained by conventional cytogenetics during the last five years, noting the type of chromosomal abnormality and the reasons for prenatal diagnosis. We have also indexed the chromosomal abnormality regarding the prognosis of the chromosomal aberations to evaluate the real impact of a non-diagnosis. Within the population of bad prognosis abnormalities, the percentage of abnormalities with bad prognosis detectable by FISH is 94.6% for advanced maternal age, 85.3% for ultrasonographic anomalies and 86.4% for positive maternal screening. The use of FISH alone on our cohort is not a suitable method to diagnose the chromosomal abnormalities.

GEMHEP multicenter quality control study of PCR detection of GB virus C/hepatitis G virus RNA in serum

PCR is, to date, the only available tool for the detection of GB virus C (GBV-C) and hepatitis G virus (HGV) RNAs. Twenty-two French laboratories participated in a quality control study to assess the sensitivity and specificity of their procedures. The panel included 13 positive controls and 7 negative controls. The laboratories used either in-house PCR techniques adapted from the literature or partly standardized commercial tests. Three laboratories performed faultlessly with the entire panel. Most laboratories had excellent specificity (100% in 20 of 22 laboratories). Sensitivity was acceptable (85 to 100%) in 15 centers and insufficient (38 to 77%) in 7. As with nonstandardized in-house PCR, the commercial assays gave discrepant performances in different laboratories. These results suggest that laboratories willing to use PCR for detection of GBV-C/HGV RNA for research or diagnostic purposes should participate in multicenter quality control trials.

Vulvar vestibulitis. Lack of evidence for a human papillomavirus etiology

Prompted by contradictory papers on the subject, we performed a prospective study to assess the possible human papillomavirus (HPV) etiology of vulvar vestibulitis. Eleven patients with periglandular vestibulitis, as well as a control group of 11 patients with condylomata acuminata, were selected. Biopsy specimens were taken for histologic and virologic evaluation. One specimen of vestibulitis showed koilocytosis. Using the polymerase chain reaction, none of the vestibulitis specimens, including the one with koilocytosis, were found to harbor HPV DNA, whereas all the condylomata acuminata contained HPV 6/11 DNA. Our results do not support an HPV etiology of vestibulitis.

Therapeutics used to alleviate peptic ulcers inhibit H. pylori receptor binding in vitro

Treatment with bismuth-containing remedies has been long associated with the alleviation of minor gastric ailments. Bismuth salts have a potent antimicrobial activity, and are part of the current standard regime used to treat Helicobacter pylori infection. H. pylori is considered to be the major etiological factor in the development of peptic ulcer disease. Earlier efficacious treatments for peptic ulcer included the oral administration of Tween detergents. We have found that these agents have an inhibitory effect on H. pylori adhesion to the lipid species phosphatidylethanolamine (PE) and gangliotetraosylceramide (Gg4) shown previously to be receptors for H. pylori binding in vitro. H. pylori binding to PE and Gg4 was inhibited after a thirty minute preincubation with different bismuth compounds: bismuth subsalicylate > bismuth subgallate > bismuth carbonate > colloidal bismuth subcitrate > tripotassium dicitrato bismuthate. No inhibitory effect on H. pylori binding was observed when bismuth salts were added directly into the binding assay. No changes in bacterial morphology and motility were observed after the thirty minute incubation. Pretreatment with Tween detergents also inhibited H. pylori receptor binding by up to 80% at concentrations as low as 0.0001%. These results suggest that inhibition of H. pylori/host cell adhesion might play a role in efficacious treatment for this infection.

Clinical features of ciguatera fish poisoning: a study of the disease in the US Virgin Islands

Clinical data were obtained on 33 patients involved in 27 episodes of ciguatera fish poisoning occurring during a 14-week period on St Thomas in the US Virgin Islands. All patients had gastrointestinal tract symptoms, with 30 patients (91%) complaining of diarrhea and 23 patients (70%) complaining of vomiting; these symptoms occurred early in the disease and were of short duration. Twenty-three patients (70%) complained of malaise, and 19 patients (58%) had pain and weakness in the lower extremities. Dysesthesias were noted by 19 patients (58%); the median duration of dysesthesias was two weeks or more, with symptoms present is some cases for more than two months. Cardiovascular signs and symptoms, including both hypotension and bradycardia were noted in some acute cases. Therapy included antidiarrheal and antiemetic agents, intravenous fluids, atropine, and pralidoxime chloride. Efficacy of pralidoxime therapy could not be established on the basis of our data.

Ciguatera fish poisoning epidemiology of the disease on St. Thomas, U.S. Virgin Islands

In a random household survey conducted on St. Thomas, U.S. Virgin Islands, the incidence of ciguatera fish poisoning was found to be 36.5 cases per 1,000 population per 5 years (95% confidence limits +/- 16.9 cases per 1,000 population per 5 years). An average of 3.6 cases per 1,000 population per year were diagnosed in the hospital emergency room on St. Thomas. Cases seen in the emergency room occurred most frequently among persons aged 30-39 years. No clear seasonality for cases could be demonstrated. In an investigation of cases occurring between 1 January and 10 April 1980, illness was caused by a variety of different fish, with carrang (Caranx ruber) the species most commonly implicated. Patients and age-matched controls ate fish with equal frequency; patients were significantly more likely to have had previous episodes of ciguatera fish poisoning than were controls.

Age at onset of necrotizing enterocolitis: an epidemiologic analysis

We studied the epidemiologic interrelationships among birth weight, gestational age, and age at onset of necrotizing enterocolitis of the newborn. As birth weight increased, the range of ages at onset and the mean age at onset both decreased. Weekly birth weight-specific attack rates for necrotizing enterocolitis declined sharply in all birth weight groups when the equivalent of 35-36 wk gestational age was reached. Our data are consistent with the hypothesis that the risk period for necrotizing enterocolitis is determined primarily by the maturity of the gastrointestinal tract of the newborn.

Epidemiologic characteristics of necrotizing enterocolitis: a population-based study

The authors studied retrospectively the epidemiologic characteristics of necrotizing enterocolitis occurring among Georgia infants born during 1977 and 1978; 148 cases of necrotizing enterocolitis were identified. The highest incidence rate for necrotizing enterocolitis occurred among infants weighing 751-1000 g at birth and declined with increasing birth weight to less than 0.2 cases per 1000 live births among infants weighing more than 2500 g at birth. The overall incidence rate for blacks was significantly greater than that for whites (1.6 vs. 0.5 cases per 1000 live births, p = 0.01). The overall case fatality ratio was 38.5%; there were no differences in these ratios between blacks and whites. Necrotizing enterocolitis accounted for 15% of all deaths after the first week of life for infants weighting 1500 g or less at birth. If Georgia incidence rates and fatality ratios are applied to 1978 US births, it is estimated that 2210 cases of necrotizing enterocolitis with over 900 associated deaths would have occurred.