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Biomedical subjects

A Smith

Publications and source records attributed to A Smith.

At least 667 records · Page 37Linked to original sources
PubMed1995

Orofacial muscle activity of children who stutter: a preliminary study.

This study was a preliminary investigation of the relations between stuttering development and the maturation of speech motor processes. Electromyographic (EMG) activity was recorded from the orofacial muscles of children who stutter and their normally fluent peers during fluent and disfluent speech. Nine children who stutter (8 boys and 1 girl), ranging in age from 2:7 to 14:0, and 9 age- and sex-matched children who do not stutter were subjects. Pairs of surface EMG electrodes were placed on children's faces overlying the anterior belly of the digastric (ABD), levator labii superior (ULIP), and orbicularis oris inferior (LLIP) muscles. Twenty segments of stuttered (for the children who stutter) and perceptually fluent speech were extracted from children's conversational speech samples. Spectra of the amplitude envelopes of the EMG activity were computed. The 3 oldest children who stutter showed evidence of tremorlike oscillations of EMG activity in the 5 to 15 Hz range during stuttering in either ULIP, LLIP, or ABD muscles. The younger children who stutter and the children who do not stutter demonstrated primary spectral peaks in the 1 to 4 Hz range during stuttered and/or perceptually fluent speech. It is hypothesized that the emergence of tremorlike instabilities in the speech motor processes of children who stutter may coincide with aspects of their general neural maturation and with the development of stuttering.

Adolescent↗
PubMed1995

An analysis of altruism: a concept of caring.

In clinical settings, nurses have observed a conflict within women who are expected to focus on caring for themselves, while their value lies in attending to the needs of others at the sacrifice of self. In this concept analysis of altruism, the term is defined and the critical attributes are identified. Model, borderline, related and contrary cases illustrate what the concept is and what it is not. The meaning of altruism is compared to self-neglect and co-dependence, which are two similar concepts. The antecedents and consequences of altruism are identified to further refine the critical attributes. Implications for research are discussed. This is a first step towards developing nursing theory that will give direction for providing more effective care to women within their value system.

Altruism↗
PubMed1995

Evaluation of interphase fluorescence in situ hybridization on direct hematological bone marrow smears.

Traditional cytogenetic analysis from bone marrow aspirates is time consuming and frequently suboptimal due to poor viability of cells in culture. Fluorescence in situ hybridization (FISH) with appropriate DNA probes is a potential alternative to routine cytogenetics. Our study examined the reliability of uptake of specific alpha satellite centromere probes from chromosome 18 (D18Z1) and X (DXZ1) and the Yq heterochromatin (pHY3.4) directly from routine hematological bone marrow smears. Altogether 34 separate hybridizations, performed on slides from 20 patients, were scored for fluorescence signals. Cells in interphase were examined with each probe using unstained slides. In addition Giemsa stained slides were destained and then used for interphase FISH. Between 412 and 631 cells were scored for the expected number of signals; 2 for the 18 centromere, 2 for the X centromere in females, one signal for the Yqh in males. The results showed the expected number of signals in 87-97% of cells with the 18 and X probes and 95-97% of cells with the Y probe. Interphase FISH is a reliable, reproducible technique for use on direct bone marrow smears.

Aneuploidy↗
PubMed1995

Abnormalities of serum type III procollagen aminoterminal peptide in methotrexate-treated psoriatic patients with normal liver histology do not correlate with hepatic ultrastructural changes.

In a previous study, it was shown that the serum levels of type III procollagen aminoterminal peptide (P3NP) were significantly greater in patients receiving methotrexate (MTX) treatment for psoriasis than in untreated control patients with psoriasis. Although levels were highest in patients with hepatic fibrosis and cirrhosis, serum P3NP concentrations in those patients with normal liver histology on light microscopy were also shown to be significantly higher than in controls. In the present study, liver biopsies from 22 such 'normal' patients were examined by electron microscopy, in order to determine whether P3NP levels correlated with ultrastructurally demonstrable fibrosis. Fibrosis in the perisinusoidal space of Disse was present in as many as 82% of biopsies. Although the prevalence of such fibrosis in psoriasis patients who have not received MTX is unknown, the high prevalence of Disse space fibrosis and of raised P3NP in MTX-treated patients suggests that MTX causes subtle liver damage in a majority of treated patients. However, we were unable to show a statistical correlation between P3NP and the degree of Disse space fibrosis.

Adult↗
PubMed1995

Bone marrow and serum connective tissue polypeptides in idiopathic myelofibrosis.

The distribution of collagen type VI and tenascin has been determined in both normal and myelofibrotic bone marrow by immunohistological techniques. In normal sections positivity was demonstrated in the periosteum (collagen type VI and tenascin) and in the walls of small blood vessels (tenascin). In contrast, myelofibrotic bone marrow showed an increased deposition of both proteins, especially collagen type VI, although this increase was restricted to the later fibrotic stages of the disease. Serum concentrations of collagen type I (PICP), collagen type III (PIIIP) and laminin (laminin P1) related polypeptides were determined in a further 26 patients. PIIIP levels were significantly raised, in contrast to PICP and laminin P1 concentrations. All three markers, however, were significantly elevated in patients with active/transforming disease. Laminin P1 and PICP levels showed a strong correlation, indicating a relationship between basement membrane and interstitial collagen metabolism, although they do not appear to offer any advantage over PIIIP for the monitoring of disease activity.

Aged↗
PubMed1995

Region 2 of the Escherichia coli K5 capsule gene cluster encoding proteins for the biosynthesis of the K5 polysaccharide.

The nucleotide sequence of region 2 of the Escherichia coli K5 capsule gene cluster has been determined. This region, essential for the biosynthesis of the K5 polysaccharide, contained four genes, termed kfiA-D. The G + C ratio was 33.4%, which was lower than the typical G + C ratio for E. coli and that of the flanking regions 1 and 3 in the K5 capsule gene cluster. Three major RNA transcripts were detected within region 2 by Northern blotting and three promoters located by transcript mapping. Promoter activity was confirmed by promoter-probe analysis. The predicted amino acid sequence of KfiC had homology to a number of glycosyl transferase enzymes and overexpression of the KfiC gene resulted in increased K5 transferase activity. The predicted amino acid sequence of KfiD had homology to a number of NAD-dependent dehydrogenase enzymes and was demonstrated to be a UDP-glucose dehydrogenase that catalyses the information of UDP-glucuronic acid from UDP-glucose.

Amino Acid Sequence↗
PubMed1995

High acceptability and low morbidity of diagnostic lumbar puncture in elderly subjects of mixed cognitive status.

A total of 273 participants (186 with clinical dementia; 87 "normal" controls; mean age 72 years) in a prospective, longitudinal, dementia research study, underwent lumbar puncture (LP), where possible, on an annual basis. Reporting of symptoms after all LP's (n = 541) was 21.6%, the predominant complaints being mild localised back-pain (12.8%) and headache (10.7%). All symptoms were self-limiting. Analysis of headaches after all first LP's (n = 273) revealed an incidence of 14.2% with marked differences between subjects under 60 years of age (33%) and those over 60 years (10.1%), between subjects with "minimal" cerebral atrophy (19.5%) and those with "significant" atrophy (5.6%) and, to a lesser extent, between subjects with no or mild cognitive impairment (20.6%) and those with significant impairment (9.5%). Age under 60 years and lack of significant cerebral atrophy were shown to be independent predictors of headache. Acceptability of LP was high as demonstrated by agreement to a second procedure by 92.2% of eligible subjects. Our results show that LP can be successfully incorporated into research with the elderly.

Adult↗
PubMed1995

Affinity, conservation, and surface exposure of hemopexin-binding proteins in Haemophilus influenzae.

Haemophilus influenzae can acquire heme from hemopexin for use as a source of both essential porphyrin and iron. In classical ligand-binding studies, we observed time-dependent, saturable, and displaceable binding of human 125I-labelled hemopexin to intact cells of H. influenzae type b (Hib) strain 760705 grown in an iron-restricted medium. From these experiments, which demonstrate that hemopexin associates with a single class of binding site, the affinities (Kds) and receptor numbers were calculated for heme-hemopexin (Kd, 205 nM; 3,200 receptors per cell) and apohemopexin (Kd, 392 nM; 4,400 receptors per cell). Thus, Hib expresses a specific hemopexin receptor which shows some preference for the heme-protein complex. Affinity chromatography on hemopexin-Sepharose 4B of detergent-solubilized membranes from Hib strain 760705 results in the copurification of three proteins with molecular masses of 57, 38, and 29 kDa. Trypsinization of whole cells of Hib 760705 abolishes hemopexin binding and correlates with the disappearance of the 57-kDa hemopexin-binding protein and appearance of a 52-kDa species which does not bind either hemopexin in ligand blot assays or a monoclonal antibody (MAbT11-30) raised against the 57-kDa protein. From immunoblotting assays and NH2-terminal amino acid sequence analysis, the 38-kDa protein isolated following hemopexin affinity chromatography was identified as the porin protein P2. These data, taken together with the receptor-binding studies which support a single class of hemopexin-binding site, suggest that P2 and the 29-kDa protein function as accessory proteins to the 57-kDa hemopexin-binding protein to facilitate the uptake of heme from receptor-bound hemopexin. To determine whether hemopexin binding and the 57-kDa protein are conserved in Haemophilus strains, whole-cell dot blots and immunoblots of the outer membrane proteins prepared from strains belonging to each of 21 different Hib outer membrane protein subtypes, six nontypeable strains, and five Haemophilus parainfluenzae strains were probed with either hemopexin or MAbT11-30. Only the H. parainfluenzae strains which lack the 57-kDa protein do not bind hemopexin. Since H. influenzae has also been shown to produce a soluble 100-kDa hemopexin-binding protein, cell-free culture supernatants were also examined for the presence of this protein. Apart from Hib 760705 and H. parainfluenzae, the 100-kDa hemopexin-binding protein was detected in all the other Haemophilus strains. The abilities of Hib 760705 to both bind and acquire heme from hemopexin without expressing a 100-kDa soluble hemopexin-binding protein show that in strain 760705, this 100-kDa protein is not essential for the utilization of heme from hemopexin.

Amino Acid Sequence↗
PubMed1995

Comparison of high resolution cytogenetics, fluorescence in situ hybridisation, and DNA studies to validate the diagnosis of Prader-Willi and Angelman's syndromes.

Eighty seven referrals with Prader-Willi syndrome and 49 with Angelman's syndrome were studied. High resolution cytogenetics was performed on all probands. Molecular studies, performed on the proband and both parents in each case, utilised multiple probes from within and distal to the 15(q11-13) region in order to establish the presence of DNA deletion or uniparental disomy. In addition, FISH, with probes at D15S11 and GABR beta 3 from the Prader-Willi syndrome/Angelman's syndrome region, was performed on a subset of 25 of these patients. In the referral group with Prader-Willi syndrome, 62 patients had a normal karyotype and 25 were deleted on high resolution cytogenetics. Twenty nine were found to be deleted with DNA techniques. In the Angelman's syndrome group, 37 had a normal karyotype and 12 were deleted on high resolution cytogenetics while 26 were deleted on molecular studies. The diagnosis was reassessed in 35 referrals with Prader-Willi syndrome and 11 with Angelman's syndrome following a non-deleted, non-disomic result. Of individuals who were neither deleted nor disomic on DNA studies, a false positive rate of 11.4% (4/35) for Prader-Willi syndrome and 16.7% (2/12) for Angelman's syndrome was found for a cytogenetically detected deletion. The false negative rate for deletion detected on high resolution cytogenetics was 19.5% (12/62) for Prader-Willi syndrome and 35% (13/37) for Angelman's syndrome. Thus high resolution cytogenetics was shown to be unreliable for deletion detection and should not be used alone to diagnose either syndrome. There were no discrepancies with FISH in 25 cases when FISH was compared with the DNA results, indicating that FISH can be used reliably for deletion detection in both syndromes.

Adolescent↗
PubMed1995

Invasive prenatal procedures: is 'backup' tissue sampling indicated?

Prenatal karyotyping was performed on 136 patients because of one or more abnormalities detected on ultrasound. A total of 188 specimens was obtained which included fetal blood, amniotic fluid and chorionic villus. In 52 patients a second or 'backup' sample was obtained and in 100% cytogenetic analysis was successful. In contrast, failure to obtain a result occurred in 4 (4.7%) of the remaining 84 patients where a second sample was not obtained. In the event of primary sample failure, backup sampling not only improves the karyotype yield, but obviates the need for a second pass procedure with its attendant risks.

Amniotic Fluid↗
PubMed1995

Neuraesthenia revisited: ICD-10 and DSM-III-R psychiatric syndromes in chronic fatigue patients and comparison subjects.

BACKGROUND: Different definitions of chronic fatigue syndrome (CFS) have different psychiatric exclusion criteria and this affects the type and frequency of associated psychiatric morbidity found. The operational criteria for neuraesthenia in ICD-10 vary in this and other respects from the Centers for Disease Control and Prevention (CDC) criteria for CFS. Neuraesthenia and associated psychiatric morbidity in CDC-defined CFS are evaluated. METHOD: CFS subjects and controls were interviewed with the Schedule for the Clinical Assessment of Neuropsychiatry (SCAN). The computerised scoring program for SCAN (CATEGO5) facilitates the assignment of operational definitions according to DSM-III-R and ICD-10. Subjects were re-interviewed with SCAN an average of 11 months later. No specific treatments or interventions were given during this period. RESULTS: The majority of subjects fulfilled ICD-10 operational criteria for neuraesthenia and had two and a half times the rate of psychiatric morbidity as the healthy comparison group according to the CATEGO5 Index of Definition (ID). Approximately 80% of subjects fulfilled both DSM-III-R and ICD-10 criteria for sleep disorders. There was a significant fall in the number of subjects fulfilling criteria for depression and anxiety disorders and a significant increase in the number of subjects with no diagnosis for DSM-III-R criteria over time. There were no significant changes over time for any diagnosis according to ICD-10 criteria or for overall levels of psychopathology as reflected in CATEGO5 ID levels. CONCLUSIONS: The ICD-10 'neuraesthenia' definition identifies almost all subjects with CDC-defined CFS. Fifty percent of CFS subjects also had depressive or anxiety disorders, some categories of which remit spontaneously over time.

Adult↗
PubMed1995

The endocrinology of the menopausal transition: a cross-sectional study of a population-based sample.

In a study of the endocrinology of the perimenopausal years, levels of serum FSH, estradiol (E2), immunoreactive inhibin (INH), testosterone, and sex hormone-binding globulin were measured in a population-based sample of 380 women (mean age, 49.4 yr; range, 45.6-56.9 yr). Subjects were divided into women who reported continuing regular menstrual cycles (27%; group I), a change in menstrual flow without a change in frequency (23%; group II), a change in frequency but no change in flow (9%; group III), changes in both frequency and flow (28%; group IV), and at least 3 months since their last menstrual period (13%; group V). After adjusting for age and body mass index, the geometric mean FSH increased across menstrual groups and, compared with group I, was 53% higher in group IV (P < 0.0005) and 253% higher in group V (P < 0.0001). Age- and body mass index-adjusted geometric means for E2 and INH in group V were 54% and 53% of those in group 1, respectively (P < 0.005, P < 0.0001). Women in group V who did not have a menstrual period in the next year had higher FSH and lower E2 and INH levels than those who subsequently went on to have at least one more menstrual period (P < 0.05). FSH was negatively correlated with E2 (r = -0.30) and INH (r = -0.39), whereas INH was positively correlated with E2 (r = 0.45). We conclude that an increase in serum FSH and decreases in E2 and INH are the major endocrine changes associated cross-sectionally with the menopausal transition.

Androgens↗
PubMed1995

Private health insurance and a healthy personality: new risk factors for obstetric intervention?

In this study 242 nulliparous pregnant women completed standardized psychometric questionnaires and semi-structured interviews in the latter half of pregnancy and again 4-6 weeks postpartum. Discriminant function analysis revealed that the use of operative obstetric interventions was measurably influenced by psychosocial factors. Privately insured women were significantly more likely to experience instrumentally assisted (relative risk = 1.53, 95% CI: 1.05, 2.25) and Caesarean (relative risk = 1.91, 95% CI: 1.05, 3.46) deliveries than those receiving care in the public hospital system. The likelihood of experiencing these procedures was increased further among those who in late pregnancy were thinking clearly, had high self-esteem, mature means of dealing with anxiety, were confident in their knowledge of childbirth procedures and in secure partnerships with highly educated men. There was no evidence that either elevated anxiety or abnormalities of personality contributed to obstetric outcome. These findings indicate that obstetric decision-making is significantly influenced by patient personality and socioeconomic circumstances. In particular, they suggest that fear of malpractice litigation, physician convenience factors and the response of obstetricians to assured, well pregnancy-educated pregnant women may be influencing the use of operative intervention in delivery.

Adult↗
PubMed1995

Detection of mRNAs for urokinase-type plasminogen activator, its receptor, and type 1 inhibitor in giant cell tumors of bone with in situ hybridization.

Although giant cell tumor of bone (GCT) is generally considered to be an uncommon benign neoplasm, it can pursue an aggressive course with local recurrence and metastasis. Attempts to predict the biological behavior of GCT with histopathological parameters, however, have not been successful. The urokinase-type plasminogen activation system has been implicated in tumor invasion and metastasis and abnormalities of the components of this system have been found in several malignancies. In this study we postulated that the urokinase-type plasminogen activation system associated with bone destruction and local invasion is present in GCT. We therefore evaluated the mRNA levels for urokinase-type plasminogen activator (u-PA), urokinase-type plasminogen activator receptor (u-PAR), and plasminogen activator inhibitor type 1 (PAI-1) by using Northern blot analysis and in situ hybridization in four cases of GCT and spindle-shaped mononuclear cells at the 35th passage from a GCT. Our results showed that giant cell tumors of bone contained variable levels of u-PA, u-PAR, and PAI-1 mRNA, respectively, 2.3, 1.4, and 3.2 kb in size. In situ hybridization showed that u-PA, u-PAR, and PAI-1 mRNA were expressed in both the mononuclear cells and the osteoclast-like giant cells; the signal for u-PA mRNA in the spindle-shaped mononuclear cells was more intense than that in the osteoclast-like multinuclear giant cells. Some spherical mononuclear cells (macrophage-like cells) expressed high levels of PAI-1 mRNA in comparison with the spindle-shaped mononuclear cells. In addition, the 35th passaged spindle-shaped mononuclear cells were used to study the gene expression of u-PA during cell proliferation. The results showed that the level of u-PA mRNA increases after adding 10% fetal calf serum to quiescent cells. The induction was maximal at 16 hours and remained high during 48 hours of treatment. In conclusion, even though osteoclast-like cells are ultimately responsible for the bone resorption of GCT, the mononuclear neoplastic cells of GCT may also be involved in degradation of the extracellular matrix during invasive growth by facilitating the urokinase plasminogen activation system. In addition, our observation of upregulation of u-PA mRNA in spindle-shaped mononuclear cells after serum stimulation indicated that u-PA production may be linked to tumor growth.

Adult↗