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Biomedical subjects

J C Anderson

Publications and source records attributed to J C Anderson.

At least 109 records · Page 6Linked to original sources
PubMed1987

DNA analysis for antenatal diagnosis of thalassaemia and haemophilia.

Two years' experience with DNA analysis for the antenatal diagnosis of thalassaemia and haemophilia is described. The advantages of DNA testing, including a first-trimester diagnosis and greater availability, must be considered in relation to the problems that are associated with this procedure. In particular, the risk of recombination in DNA polymorphism studies should be understood and explained fully to the patient.

Amniocentesis↗
PubMed1987

DSM-III disorders in preadolescent children. Prevalence in a large sample from the general population.

We investigated the prevalence of DSM-III disorders in 792 children aged 11 years from the general population and found an overall prevalence of disorder of 17.6% with a sex ratio (boys-girls) of 1.7:1. The most prevalent disorders were attention deficit, oppositional, and separation anxiety disorders, and the least prevalent were depression and social phobia. Conduct disorder, overanxious disorder, and simple phobia had intermediate prevalences. Pervasive disorders, reported by more than one source, had an overall prevalence of 7.3%. Examination of background behavioral data disclosed that children identified at 11 years as having multiple disorders had a history of behavior problems since 5 years of age on parent and teacher reports. Fifty-five percent of the disorders occurred in combination with one or more other disorders, and 45% as a single disorder.

Anxiety Disorders↗
PubMed1987

Pulsatile intravenous gonadotropin-releasing hormone for ovulation-induction in infertile women. II. Analysis of follicular and luteal phase responses.

Pulsatile intravenous gonadotropin releasing hormone (IV-GnRH) was used in 36 infertile patients with primary amenorrhea (n = 5), secondary amenorrhea due to hypothalamic chronic anovulation (HCA) (n = 22), hyperprolactinemia (n = 1) or polycystic ovary syndrome (PCOS) (n = 5), and oligomenorrhea (n = 3), using several dosage and timing regimens. Early follicular phase responses showed four patterns: type 1 consisted of a delayed follicle-stimulating hormone (FSH) peak and was seen with severe hypothalamic suppression (n = 4); type 2 consisted of a brisk and dominant FSH peak on the first day of treatment, and occurred with mild to moderate hypothalamic suppression (n = 19); type 3, which consisted of an FSH peak accompanied by an immediate and exaggerated luteinizing hormone (LH) rise, occurred with mild PCOS and some cases of HCA (n = 5); and type 4, in which LH levels were high to begin with and neither FSH nor LH levels rose with GnRH, occurred with severe PCOS (n = 2). Exaggerated estradiol responses within 24 hours of therapy were seen in eight cycles: in four cases no ovarian abnormality was apparent; in three cases a dominant follicle was already present; and in one case ovarian hyperstimulation was diagnosed ultrasonographically. With standard human chorionic gonadotropin luteal phase support, luteal phase defects were rare with HCA but common with PCOS.

Estradiol↗
PubMed1987

Dissemination of staphylococci in mice with experimental mastitis.

During the course of an acute, fatal mastitis in mice caused by intra-mammary injection of approximately 10(5) cfu of Staphylococcus aureus, small numbers of staphylococci were detected in liver, spleen, kidney and heart. Transport from the mammary gland was by the venous blood system with no evidence of lymph node involvement. Intravenous injection of 100 times more staphylococci (approximately 10(7) cfu) than were fatal by the intramammary route failed to kill the mice and small numbers of staphylococci were found in the visceral organs. However, intravenous injection of approximately 10(8) cfu of Staph. aureus was fatal and large numbers of staphylococci were found in the visceral organs. Treatment with cloxacillin (500 micrograms) by the intramammary or subcutaneous routes, or equally divided between these two routes, cleared the visceral organs of staphylococci; subcutaneous therapy had a limited and variable effect on numbers of staphylococci in the mammary gland while intramammary and divided treatments significantly reduced the numbers of staphylococci. Thus, staphylococci are disseminated to visceral organs during acute staphylococcal mastitis, but this makes a negligible contribution to the clinical disease.

Animals↗
PubMed1987

Biochemical investigation of possible lesions in human aorta that predispose to dissecting aneurysms: pyridinoline crosslinks.

Pyridinoline, a collagen specific covalent crosslink, was quantified in acid hydrolysates of human aorta using a non-equilibrium inhibition ELISA. The study was based on specimens from seven cases of aortic dissection and from seven control subjects whose death was unrelated to thoracic aortic dissection. There were no significant differences in the amounts or concentrations of pyridinoline in aortas with dissecting aneurysms compared with normal tissue, thus excluding the possibility of a causative relation between the degree of pyridinoline crosslinking of collagen molecules and dissection of the thoracic aorta. In all cases, however, the number of pyridinoline crosslinks per molecule of collagen in the ascending aorta and arch approached the theoretical maximum for lysyl derivatives and was as high as that present in cartilage. Thus in this region of the vessel pyridinoline represents the major stabilising crosslink of collagen. In contrast, the number of pyridinoline crosslinks per collagen molecule decreased maximally by a factor of 10 between the arch and the proximal regions of the descending thoracic aorta. This suggests a possible correlation between the rigidity of collagen fibres and the forces exerted on the aortic wall during diastole and systole.

Aged↗
PubMed1987

Factors affecting the activation state and the level of total activity of ribulose bisphosphate carboxylase in tobacco protoplasts.

The relationship between the activation state and the level of total activatable activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) was examined in tobacco protoplasts. When darkened protoplasts were illuminated, both activation and total activity increased, but at different rates; the t((1/2)) were 2.3 and 6.7 minutes, respectively. The light response of rubisco activation state and total activity, measured after 15 minutes of illumination, were similar but their responses to light transitions and photosynthetic inhibitors were different. When irradiance was reduced from saturating to subsaturating, deactivation of rubisco in protoplasts was immediate, whereas there was little change in total activity during the first 20 minutes following the transition. The light-induced increases in activation state and total activity were inhibited by nigericin, but activation was more sensitive exhibiting a response similar to that of photosynthesis. Treatment of tobacco protoplasts and leaves with methyl viologen at limiting irradiance increased rubisco activation, but inhibited the light-induced increase in total activity. These results indicate that light activation of rubisco is mechanistically distinct from the light-dependent changes in total activity in tobacco, a species containing carboxyarabinitol 1-phosphate, an endogenous inhibitor of total rubisco activity.

Journal Article↗
PubMed1987

Watchful waiting of a fetus with zone III amniotic fluid values.

A case of Rh negative, sensitized patient was observed while her amniotic fluid values climbed through zone III of Liley's graph. The fetus was monitored weekly with ultrasound and delivered when it had a mature lung profile. It is not always necessary to proceed with immediate fetal therapy whenever amniotic fluid values are in zone III.

Adult↗
PubMed1987

Limb-length discrepancy measured with computerized axial tomographic equipment.

A simple, rapid, and accurate method for measuring limb-length discrepancies with computerized axial tomographic equipment is described. With this method less irradiation is delivered and some of the errors of computation are eliminated, compared with conventional methods. The costs of the technique are comparable with those of scanograms. The method is particularly applicable in the patient who has contracture of a joint.

Adult↗
PubMed1987

Avoidance of maternal morbidity in acute intrauterine infection following chorionic villus sampling.

Serious maternal morbidity has been a feature of the few documented cases of acute intrauterine infection after chorionic villus sampling. A case is described in which infection manifested 14 days after transcervical chorion biopsy. Broad-spectrum antibiotics were begun, and ultrasound demonstrated a live fetus. After vacuum curettage was performed, repeat scan showed an empty uterus. Anaerobes isolated from the cervix both before chorionic villus sampling and during the infection were also implicated in published reports of patients developing life-threatening complications, but were not treated specifically until after morbid sequelae had occurred. Serious morbidity was avoided in this patient by aggressive management with early anaerobic cover, uterine evacuation despite the presence of a live fetus, and confirmation of complete evacuation by ultrasound.

Abortion, Therapeutic↗
PubMed1986

Antimicrobial drug susceptibility of Staphylococcus aureus isolated from bovine mastitis.

Isolates of Staphylococcus aureus (106) from bovine mastitis were tested for susceptibility to antimicrobial agents. beta-lactamase was produced by 69.8 per cent of isolates and 7.5 per cent were resistant to streptomycin (minimum inhibitory concentration more than 32 micrograms/ml). Resistance to other agents was rare. Intrinsic resistance or tolerance to beta-lactam antibiotics was not found.

Animals↗
PubMed1986

Clinical experience with 50 cases of first-trimester fetal diagnosis by chorionic biopsy.

Prenatal diagnosis by chorionic biopsy was undertaken between the eighth and 12th weeks of pregnancy in 50 patients at risk of chromosomal or genetic abnormalities. Samples from 45 patients were karyotyped. A DNA analysis for the detection of homozygous beta-thalassaemia was undertaken in five patients. The sample from one patient at risk of haemophilia in the fetus was subjected to DNA analysis after a male fetus was confirmed on karyotyping. Abnormal karyotypes were detected in four fetuses while three had homozygous beta-thalassaemia.

Abortion, Spontaneous↗
PubMed1986

Fetal response decrement: true habituation?

Preliminary evidence suggests that fetal movement in response to vibrotactile stimulation "habituates" with repeated exposure. If demonstrated in fetuses, the habituation paradigm may be useful as a measure of fetal well-being or as a predictor of neonatal outcome. However, the ability of the fetal response decrement phenomenon to meet criteria for habituation which would distinguish it from simple receptor fatigue has not been evaluated. In this study, fetuses were exposed to two different frequencies of vibration applied to the maternal abdomen. Fetal movement was observed on an ultrasound monitor. An inverse relationship between the strength of the stimulus and rapidity of the response decrement was not observed. However, return of the response to presentation of a novel stimulus, response decrement to repetition of the second stimulus, and more rapid response decrement upon re-presentation of the original stimulus suggest that the fetal response decrement phenomenon is true habituation.

Arousal↗
PubMed1986

The effect of incorporation of cloxacillin in liposomes on treatment of experimental staphylococcal mastitis in mice.

The effect of incorporation of cloxacillin in liposomes on the treatment of staphylococcal mastitis was assessed bacteriologically 18 h after treatment of experimental infections in mice caused by two strains of Staphylococcus aureus. Intramammary treatments were cloxacillin incorporated in liposomes, cloxacillin in combination with liposomes, empty liposomes, cloxacillin in saline and saline alone. In none of the experiments did entrapment of cloxacillin within liposomes enhance its antibacterial effects. Electron microscopic studies demonstrated the presence of liposomes in neutrophils which also contained staphylococci. The results support the hypothesis that intracellular staphylococci are metabolically dormant and therefore not susceptible to the action of inhibitors of cell wall synthesis such as cloxacillin.

Animals↗
PubMed1986

The value of hepatic ultrasound and biochemical liver tests in screening for liver metastases.

The records of 92 patients with a known diagnosis of extrahepatic cancer who had undergone hepatic ultrasound, biochemical liver tests (alkaline phosphatase, SGOT, lactic dehydrogenase, and bilirubin levels), and subsequent liver biopsy or autopsy within a 6-week period were reviewed. The sensitivity, specificity, and accuracy of the ultrasound and biochemical tests in the detection of metastatic liver disease were calculated. Although there was no significant difference in the sensitivity of either examination, the ultrasound demonstrated higher specificity and accuracy than the biochemical liver tests. The high sensitivity of hepatic ultrasound prevailed even in patients with normal biochemical liver tests. The sensitivity of hepatic ultrasound was significantly lower in patients with lymphoma compared with patients with colorectal cancer (50% v 100%, P less than .05). Notable incidental extrahepatic findings were reported in 25% of the ultrasound examinations. In institutions skilled in sonography, hepatic ultrasound may be a superior tool in the detection of liver metastases in most solid tumors, excluding lymphoma, and offers the additional advantage of simultaneous biliary tract and perihepatic visualization.

Alkaline Phosphatase↗