January 27th, 2007
Regarding mandatory (with parent opt-out) HPV vaccination for Kansas girls, Dawn Richardson, from a nutty anti-vaccine group (in Texas), says, "."
Nevermind that according to the CDC, "Approximately 20 million people are currently infected with HPV. At least 50 percent of sexually active men and women acquire genital HPV infection at some point in their lives. By age 50, at least 80 percent of women will have acquired genital HPV infection. About 6.2 million Americans get a new genital HPV infection each year." I suppose 80% of women just come from bad homes and are irresponsible.
Folks, remember not to let extreme bias that would endanger girls and women for the sake of appearing to be from "a good home" be the only source you go to for vaccination information. While it's true that long-term safety data is not yet available for this very new vaccine, you should be aware that many opponents of the vaccine are so because of reasons that have nothing to do with actual scientific data. Read the rest of this entry »
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July 4th, 2006
HeartPoint is primarily designed for people interested in heart disease in adults. Since we've come on line however, it's become apparent that there is also a great deal of interest in congenital heart disease, disorders that generally affect children. It is a vast topic, and one that is difficult to generalize about.
Congenital Heart Disease are defects present from birth and effect a little less than 1% of all children. The heart starts in the embryo as a simple pulsatile tube, and must twist and rotate, cavitate, form valves, etc. to form the complex four chambered organ - there are ample opportunities for something to go wrong. It is not surprising that abnormalities can occur, perhaps it is only surprising they occur so infrequently. They may take the form of abnormal holes between the chambers of the heart, incorrect connections between chambers and vessels, valves which don't open properly, or others.
The causes are difficult to determine and probably different in each case.
* Abnormalities of the chromosomes which carry genetic information are associated with congenital heart disease. Persons with well described complex congenital abnormalities, such as Down's syndrome and many others, have an increased incidence of certain types of congenital heart disease.
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June 4th, 2006
What is a congenital cardiovascular defect?
Congenital means inborn or existing at birth. Among the terms you may hear are congenital heart defect, congenital heart disease and congenital cardiovascular disease. The word "defect" is more accurate than "disease." A congenital cardiovascular defect occurs when the heart or blood vessels near the heart don't develop normally before birth.
What causes congenital cardiovascular defects?
Congenital cardiovascular defects are present in about 1 percent of live births. They're the most common congenital malformations in newborns. In most cases scientists don't know why they occur. Sometimes a viral infection causes serious problems. German measles (rubella) is an example. If a woman contracts German measles while pregnant, it can interfere with how her baby's heart develops or produce other malformations. Other viral diseases also may cause congenital defects.
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March 7th, 2006
A method is described enabling prenatal diagnosis of glycogenosis II (Pompe's disease) within 7—10 days after amniocentesis in the 14th—16th week of pregnancy. The procedure is based on amniotic fluid cell cultivation on thin plastic foil, freezing and freeze-drying of the cells and subsequent microdissection of pieces of plastic foil each containing 70-250 lyophilized cells. These are incubated in microliter volumes of substrate. The extinction or fluorescence values are measured in microcuvettes adapted to a normal spectrofluorometer or in microcapillaries using a microscope spectrofluoiometer design. The methods developed are compared with conventional biochemical analyses.
INTRODUCTION
Hers1 delineated the basic defect in type II glycogenosis (Pompe's disease) as a deficient activity of the lysosomal acid a-i,4-glucosidase. In patients with Pompe's disease this enzyme deficiency has been demonstrated in various tissues and organs2.3. Nitowsky and Gninfeld4 showed that the acid α-glucosidase deficiency is also exÂpressed in leucocytes and in cultivated skin fibroblasts. This not only facilitated the diagnosis of patients and heterozygous carriers but also formed the basis for prenatal detection of this autosomal recessive disease. The first examples of prenatal diagÂnosis of Pompe's disease were based on a deficiency of α-glucosidase in amniotic fluid, in uncultivated and cultivated fluid cells5.6. Later, it became apparent that the use of amniotic fluid and uncultivated cells could result in erroneous interpretations (refs. 7, 8), because of the possibility of contamination with maternal components and because of the presence in amniotic fluid of an α-glucosidase with different properties than the lysosomal acid glucosidase which is deficient in Pompe's disease'.9.
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March 7th, 2006
Summary. 1. A method for freezing uncultured amniotic fluid cells is presented, which allows their use as pregnancy-age matched controls in prenatal diagnosis of metabolic diseases. 2. Amniotic fluid cells were successfully cultured after up to 7 days in transport, which makes prenatal diagnosis available to parents living a long way from specialized centers.
Zusammenjassung. 1. Eine Einfriermethode fiir nichtkultivierte Fruchtwasserzellen wird beschrieben, wodurch man diese wie Kontrollmuster anwenden kann bei pranataler Diagnostik von Stoffwechselkrankhciten. 2. Fruchtwasserzellen wurden erfolgreich kultiviert nach lang-zeitigem Transport (7 Tage); dieser Befund bringt eine pranatale Diagnostik im Bereich ent-fernt von spezialisierten Zentren lebender Eltern.
An increasing number of inborn errors of metabolism nan he detected in early pregnancy (Milunsky et al., 1970; Milunsky and Littlofield, 1972). Until now metabolic defects have been determined by biochemical analysis of cell homo-genates obtained from large numbers (millions) of cultured amniotic-fluid cells. As a consequence the period of time required for prenatal diagnosis in most inÂstances has been very long (4—10 weeks) (Brady et al., 1971 ; Fratantoni et al., 1969; Epstein et al., 1972; Cox et al., 1970).
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March 3rd, 2006
This thesis deals with several methodological and practical aspects of prenatal diagnosis.
A genetic metabolic disease can only be detected in utero if the enzymatic defect or storage of a specific metabolite is expressed in cultured cells from an affected individual. This should be demonstrated for each separate disease. An- example of such a study is presented in appendix paper I. The data inÂdicate, that the enzymatic defect in the haemolytic anaemia caused by pyruÂvate kinase deficiency (an autosomal recessive disease) is not detectable in fibroblasts and cultured amniotic fluid cells, since these only produce the M-type of this enzyme, whereas the anaemia is related to a deficient activiÂty of the L-type. As a consequence, prenatal diagnosis of this disease is not possible.
The prenatal diagnosis of enzymatic defects requires analysis of a sufficient number of amniotic fluid cell cultures cultivated under identical conditions and for a comparable period as the diagnostic sample. Sufficient amniotic fluid samples from normal pregnancies will generally not be available at the very moment these are required. To solve this problem a method was develop-ped to store uncultured amniotic fluid cells without loss of cell viability. This method is described in appendix paper II and has enabled us to collect suffiÂcient control material for later use in prenatal diagnosis of enzymatic defects. The possible detrimental effects of transport periods of up to a few days on the viability of amniotic fluid cells was tested simultaneously and the results indicate that transport during periods of up to seven days did not interfere with succesfull cell cultivation. This means that prenatal diagnosis can be offered to people living at long distances from the center performing the anaÂlysis.
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March 3rd, 2006
Open defects of the neural tube (anencephaly and meningomyelocele) are reÂlatively frequent congenital malformations of multifactorial origin. The recurÂrence risk after one affected child is about 5% and after two affected childÂren it increases to + 10% (Bonaiti-Pellie & Smith, 1974). The malformation in the subsequent child may be either identical or of a different type. An affected parent has a 3 - 4% risk for an affected child (Carter, 1974). Prenatal detection of open neural tube defects is possible by analysis of the concentration of alpha-fetoprotein in the amniotic fluid (Brock & Sutcliffe, 1972; Allan et aL, 1973); closed defects, some of which may have milder clinical manifestations, cannot be detected with this method (Laurence et al., 1973) and the parents should be informed accordingly.
This recent development will be a quite common indication for prenatal moniÂtoring, and in most cases this will be for parents with an affected child. Elevated levels of amniotic fluid alpha-fetoprotein can in some cases also be detected in maternal serum (Brock et al., 1973). In a number of studies the value of this maternal indicator for fetal neural tube defects was explored (Harris et al., 1974; Seller et al., 1974; Wald et al., 1974). The possibiliÂties for large-scale screening so far are not very promising.
Future developments in prenatal diagnosis
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March 3rd, 2006
About 50 severe recessive autosomal or X-linked diseases can now be detected in utero by biochemical assays of cultured amniotic fluid cells (for reviews, see: Milunsky et al., 1970; Milunsky & Littlefield, 1972; Burton et al.,1974). In autosomal recessive diseases the diagnosis of a first affected child usually is the first indication that both parents are carriers of the same gene mutation. The recurrence risk is 25%. Prenatal diagnosis in future pregnancies of these parents will only be reliable if cultured cells of the affected child are a-vailable. The prenatal diagnosis will be based on a comparison of the bioÂchemical assays on amniotic fluid cells from the pregnancy at risk, control cells from a normal pregnancy cultured under identical conditions and fibro- blasts from the patient with the metabolic defect.
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March 3rd, 2006
When the mother is a carrier of an X-linked disease, there is a 50% chance for her son to be affected. Prenatal sex determination by chromosome analysis may help these parents to limit their families to unaffected daughters (who will be carriers in 50% of the cases). The limitations of this approach are obÂvious, but it is the only possibility for these parents to have their own childÂren, without being forced to accept a high risk for a severely affected child. This approach applies to those X-linked disorders where the basic defect is unÂknown, (e.g. Duchenne's muscular dystrophy, X-linked mental retardation, etc.) or is not yet detectable in amniotic fluid or cultured amniotic fluid cells (e.g. hemophilia). In a few X-linked diseases the biochemical defect is expressed in cultured amniotic fluid cells and this allows prenatal identificaÂtion of an affected male fetus (Fabry's disease; Hunter's disease; the Lesch-Nyhan syndrome; for references: see Burton et al., 1974).
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March 3rd, 2006
The most frequent examples are the recurrence risk of trisomy 21 (Down's synÂdrome) and the risk for chromosomal aneuploidies at advanced maternal age (38 years and older).
The recurrence risk for trisomy 21 is 1% as calculated either from retrospective data (Pfeiffer et al., 1973) or from prospective series of prenatal diagnoses for this indication (Milunsky, 1973). The recurrence risk of other numerical aberraÂtions is less well known. This is related to the question of the presence in man of a familial tendency to non-disjunction. Two types of evidence for this phenomenon are present:
a. A number of sibships have been described with aneuploidies for different chroÂmosomes (Girardet et al.,1972; Bell & Cripps, 1974; Holmgren & AWhn, 1971; Hamerton, 1971).
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