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Biomedical subjects

A Robinson

Publications and source records attributed to A Robinson.

At least 343 records · Page 19Linked to original sources
PubMed1989

Verbal and spatial processing efficiency in 32 children with sex chromosome abnormalities.

Spatial and linguistic processing efficiency was evaluated in sixty 8- to 18-yr-old children, including thirteen 47,XXY boys, eleven 47,XXX girls, six girls with 45,X, two girls with 46,X,Xq-, and 28 chromosomally normal controls. Results indicated that the 47,XXX girls performed significantly below controls on all four cognitive tests. Scores of the X monosomy group were reduced on both spatial tests, one requiring rapid information processing and one without time requirements, which is consistent with previous reports of spatial thinking deficits in these propositae. The X monosomy girls also had difficulty completing the high efficiency but not the low efficiency verbal tests. Scores in the 47,XXY group did not differ from controls on either spatial test or on the low efficiency verbal task. When required to rapidly access verbal information from memory, however, the performance of these boys was significantly impaired. This finding confirms earlier reports of impeded verbal fluency in these propositi. Alteration in capacity to rapidly process information appears to distinguish 47,XXY boys and X monosomy girls from their chromosomally normal peers, and suggests that adaptations in their educational setting should be introduced to allow additional time to learn and complete work.

Adolescent↗
PubMed1989

Lymphoma of uterine cervix.

Two patients with malignant lymphoma of the cervix treated with radiotherapy and chemotherapy are reported. Both are alive and disease-free 8 years later. The literature is reviewed to define the role of the different treatment modalities.

Adult↗
PubMed1989

Interaction between cortisol and microbial proteases.

Binding (or interaction) of cortisol with microbial molecule(s) was observed by employing Bio-Gel HTP affinity chromatography and subsequently by fluorescence spectrophotometry. Molecule(s) in the crude extract of baker's yeast and in other microbial proteases exhibited varied degrees of cortisol-binding. Bacterial protease (type IX) had highest, while the type XXVI enzyme had the lowest, binding capacity. In addition, these two proteases exhibited a distinct difference in the alterations of ultraviolet spectra due to interaction with cortisol. Using casein as a substrate, cortisol, CTP, trypsin inhibitor or leupeptin appreciably inhibited type IX protease at low concentrations of Ca2+. However, thyroxine had no effect on this protease.

Bacteria↗
PubMed1989

Food hoarding behaviour in the golden hamster (Mesocricetus auratus): effects of body weight loss and hoard-size discrimination.

Two experiments investigated some of the factors that influence food hoarding behaviour in the golden hamster (Mesocricetus auratus). In Experiment 1, hamsters given limited access to food failed to increase the amount of food they consumed at each meal. Instead, they exhibited a significant increase in the amount of food taken to hoard during the limited access period, and this permitted hamsters who were allowed to retain their hoard to maintain body weight at levels comparable to free-feeding controls. Hamsters that were not allowed to retain hoarded food rapidly lost body weight. There was also an inverse correlation between body weight and amount of food taken to hoard in all hamsters given limited access to food, suggesting that body weight loss was one factor directly related to increased hoarding during periods of limited food accessibility. Experiment 2 investigated the effect of hoard-size discrimination on food hoarding in hamsters by artificially manipulating hoard size. The results suggested that hoarding behaviour could be influenced by artificially depleting and repleting the hoard, and this factor appears to influence hoarding in the absence of any significant changes in body weight. These results are discussed in relation to the kinds of adaptive feeding strategies that hamsters may utilize in their natural environment.

Animals↗
PubMed1989

Surgical treatment of skin cancer.

Eight hundred and twenty cases of skin cancer treated surgically at Saint Luke's Hospital over a ten-year period were reviewed retrospectively. Those undergoing excision, ie simple excision and primary closure, had significantly shorter hospitalization than those requiring grafts or amputation. The only prognostic factor in this particular series identified for local recurrence was a past history of skin carcinoma. Surgery was effective both as primary treatment and after failed irradiation. Local recurrence rates for skin carcinoma and melanoma were 8% and 10% respectively.

Basal Cell Carcinoma↗
PubMed1989

Gross and fine motor development in 45,X and 47,XXX girls.

Neuromuscular deficits have been described in 47,XXY and 47,XYY boys, but gross and fine motor development of girls with sex chromosome aneuploidy has not been extensively studied. Twenty-one propositae 8 to 19 years of age, identified through newborn screening to be 45,X, 47,XXX, or 45,X mosaic, and 11 control girls were evaluated by a physical therapist unaware of their genetic constitution. The Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) was administered, and the quality of neuromuscular function was determined. The 45,X and 47,XXX propositae exhibited both gross and fine motor dysfunction, with 12 of 15 BOTMP composite scores below the 10th percentile. The clinical assessment confirmed the BOTMP findings, with 13 propositae exhibiting dysfunctional sensory-motor integration. A delay in the age of independent walking confirmed the consistency of motor developmental dysfunction throughout time. Sex chromosome mosaics were more similar to control girls. The gross and fine motor delays were frequently associated with a moderate to severe language dysfunction which adversely affected classroom performance. Regular developmental assessments of children with sex chromosome aneuploidy, including sensory-motor integration, should assist in the identification of early developmental delays and permit appropriate intervention.

Adolescent↗
PubMed1988

45,X/46,XY mosaicism: contrast of prenatal and postnatal diagnosis.

The process of prenatal diagnosis is unique in that the diagnosis and prognosis are made without seeing the patient. 45,X/46,XY mosaicism presents a special problem in this regard. The phenotype of 45,X/46,XY postnatally diagnosed children (pediatric group) was compared to that of 6 fetuses who were diagnosed from 7,000 amniocenteses (prenatal group). These amniocenteses were performed primarily because of an increased risk of chromosome abnormality. The pediatric group (age birth-18 yr) were all phenotypically abnormal, although none were mentally retarded. Seven patients presented with ambiguous genitalia, while 2 had primary amenorrhea. Sexual assignment was changed in 2. Abnormalities included rudimentary phallus, urogenital sinus, hypospadias, undescended testes, and short stature. All 9 patients required at least one surgical procedure. In contrast, the prenatally diagnosed fetuses (ages 3 months to 3 1/2 yr) were all phenotypically normal males. Four were noted to have male genitalia on ultrasonography. Thus, the phenotype of 45,X/46,XY mosaicism in prenatally diagnosed fetuses can be markedly different from that of individuals diagnosed postnatally. This must be considered when counseling patients.

Amenorrhea↗
PubMed1988

Isochromosome 12p mosaicism (Pallister-Killian syndrome): newborn diagnosis by direct bone marrow analysis.

A patient who exhibited the phenotype of the Pallister mosaic aneuploid syndrome was cytogenetically diagnosed in the newborn period by bone marrow analysis. A 47,XY,i(12p) karyotype was observed in 100% of the metaphases from direct bone marrow preparations, while phytohemagglutinin (PHA)-stimulated bone marrow was 23% isochromosome positive. Initially, 10% of metaphases from a peripheral blood culture were isochromosome positive, but at 2 months of age all metaphases examined were cytogenetically normal. Serial fibroblast cultures were 75%, 100%, and 28% positive, respectively. The isochromosome was also present in all metaphases examined from lung tissue and testes. This karyotypic pattern supports a theory that tissue-limited mosaicism may result from selection due to differing developmental potentials of certain karyotypes in various tissues.

Abnormalities, Multiple↗
PubMed1988

Antioxidants to treat chronic pancreatitis in childhood? Case report and possible implications for pathogenesis.

The case history of a 10-yr old boy with calcific chronic pancreatitis is reported. His theophylline clearance of 450 ml/kg/h was several times higher than normal, indicating induction of cytochromes P450. Painful attacks disappeared concurrently with administration of antioxidants. The possible relevance of these findings is discussed in the context of chronic pancreatitis in childhood.

Antioxidants↗
PubMed1988

Trial of a new acellular pertussis vaccine in healthy adult volunteers.

Immunogenicity and reactogenicity of a new acellular pertussis vaccine were tested in healthy adults. The vaccine contained three constituents of Bordetella pertussis; filamentous haemagglutinin, pertussis toxin (PT) and fimbriae bearing agglutinogens 2 and 3. The constituents were separately purified, treated with formaldehyde and combined with one of two aluminium adjuvants. Subjects received one dose of vaccine or an appropriate adjuvant-only preparation and were monitored for clinical responses for 7 days. Results with the two forms of vaccine were similar. Of 35 vaccinees, none had a temperature higher than 37 degrees C or a severe reaction, one had a moderate reaction (possibly due in part to intercurrent infection) and nine had mild reactions confined to localized discomfort and/or erythema or induration at the injection site. All vaccinees had good serum antibody responses to vaccine antigens measured by ELISA and for PT, by neutralization of its effects on Chinese hamster ovary cells.

Adjuvants, Immunologic↗
PubMed1988

Recovery of Malassezia pachydermatis from eight infants in a neonatal intensive care nursery: clinical and laboratory features.

A 15-month retrospective survey of 507 admissions to a neonatal intensive care unit revealed 8 patients from whom Malassezia pachydermatis was isolated from one or more clinical specimens. The fungus was cultured from blood (four patients), central venous catheter tips (three patients), urine (four patients), cerebrospinal fluid (one patient), eye discharge (one patient), ear discharge (one patient) and tracheal aspirate (one patient). Seven of the eight infants displayed an episode of one or more of the following symptoms: apnea, bradycardia, temperature instability and hepatosplenomegaly. These episodes were temporally related to recovery of M. pachydermatis from clinical specimens. The seven symptomatic infants had received multiple antibiotics as well as long term hyperalimentation, including lipids, by infusion through deep vein catheters; the single asymptomatic infant did not. These data suggest an association between M. pachydermatis and the febrile systemic syndrome of neonates recently described for extracutaneous infections due to Malassezia furfur.

Anti-Bacterial Agents↗
PubMed1988

47,XXX: what is the prognosis?

Eleven unselected 47,XXX girls, now 15 to 22 years of age, have been observed from birth in a prospective study of children with sex chromosome anomalies. A description of their growth and development is presented. The 47,XXX infants were not generally distinguishable from chromosomally normal children in the first year of life, even though there was a slight delay in neuromotor development. By 2 years of age, developmental delays in speech and language often became evident, and speech therapy was often necessitated in the preschool years. Early school problems included speech and language deficiencies, lack of coordination, poor academic performance, and immature behavior; these persisted throughout the school years. By high school age, a 47,XXX girl was generally tall and often subject to somatic complaints. Sexual development was generally normal. Seven of the 11 propositae had a diagnosed psychiatric disorder or disturbance at some time during adolescence. Variability within this syndrome is great; one proposita is in college and another is mentally retarded. The frequency of the diagnosis of the 47,XXX karyotype by genetic amniocentesis is estimated to be 1/1000, the same incidence as in the newborn population. Expectant parents must be counseled as to the significance of this karyotype and prognostic information must be given. Suggested guidelines are included.

Adaptation, Psychological↗
PubMed1988

Agglutinogens and fimbriae of Bordetella pertussis.

Agglutinogen 2 (AGG2) of Bordetella pertussis is a fimbrial antigen and therefore a potential adhesin and acellular vaccine component. AGG2 was found to dissociate only under harsh conditions into the subunits of mol. wt. 22500 seen in SDS-PAGE. Results from studies of agglutinogen 3 (AGG3) are presented which confirm previous findings from this Laboratory that AGG3 is also a fimbrial protein but with a subunit mol. wt. of 22000. The amino acid sequence of AGG2, deduced from the nucleotide sequence of the gene encoding it, was used as a basis for synthesis of three peptides. Coupled to Keyhole Limpet Haemocyanin (KLH), the peptides were immunogenic in mice, inducing antibodies which bound well to homologous peptide in ELISA but poorly to intact fimbriae. Monoclonal and polyclonal serotype-specific antibodies failed to react significantly with the peptides or their KLH-conjugates. These results indicate that the synthetic peptides do not represent the serotype 2 epitope. Mice immunized with purified AGG2 or AGG3 were found to be protected against respiratory infection with B. pertussis. Results presented here indicate that this protection is, to a large extent, serotype-specific and that immunization of mice with AGG2 or AGG3 can lead to a change in serotype of the infecting strain. These results are analogous to findings from epidemiological studies of the protection induced in children by whole cell vaccines. They reaffirm the importance of both AGG2 and AGG3 as components of whole cell and acellular vaccines.

Amino Acid Sequence↗
PubMed1988

Carpal tunnel syndrome in patients who are receiving long-term renal hemodialysis.

In forty-six (9 per cent) of 485 patients who were receiving long-term renal hemodialysis, a carpal tunnel syndrome developed in at least one hand. A total of sixty-four surgical procedures were performed for this problem in forty-one patients. All of the forty-one patients reported symptomatic relief, although three had recurrent symptoms. There was no correlation between the time of onset of the carpal tunnel syndrome and such factors as the patient's age, sex, or race; the cause of renal failure; the site of vascular access for hemodialysis; or a history of parathyroidectomy. There was a correlation, however, between the development of the carpal tunnel syndrome, the side of the longest functional vascular access, and the presence of arterial calcifications. In all eleven patients in whom a radial steal syndrome developed, an ipsilateral carpal-tunnel syndrome also developed. It was concluded that factors other than those involving the site of vascular access must have important etiological roles.

Adult↗
PubMed1987

The role of topogenic sequences in the movement of proteins through membranes.

Recent advances have led to considerable convergence in ideas of the way topogenic sequences act to translocate proteins across various intracellular membranes (Table 2). Whereas co-translational translocation and processing were previously considered the norm at the endoplasmic reticulum membrane, several instances of post-translational translocation into endoplasmic reticulum microsomes in vitro have now been described. However, it must be noted that post-translational translocation in vitro is much less efficient than when endoplasmic reticulum membranes are present during translation, and it is possible that in the intact cell translocation occurs during translation. Movement of proteins into chloroplasts and mitochondria occurs after translation. When translocation is post-translational, proteins may perhaps traverse the membrane as folded domains, and the conformational effects of topogenic sequences on these domains may be as envisaged in Wickner's 'membrane-trigger hypothesis'. Both signal and transit sequences possess amphipathic structures which are capable of interacting with phospholipid bilayers, and these interactions may disturb the bilayer sufficiently to allow entry of the following domains of protein. There is increasing evidence that GTP is required to bind ribosomes and their associated nascent chains to the endoplasmic reticulum membrane. Precisely how the cell's energy is applied to achieve translocation is not clear, but one possibility at the endoplasmic reticulum is that a GTP-hydrolysing transducing mechanism may exist to couple signal sequence receptor binding to movement of the nascent chain across the membrane. Electrochemical gradients are required for protein movement to the mitochondrial inner membrane and across the bacterial inner membrane. Cytoplasmic factors such as SRP, the secA gene product or a 40 kDa protein (for mitochondrial precursors) may act by binding to topogenic sequences and preventing precursor proteins as they are translated from folding into forms which cannot be translocated. Specificity in the cell may be achieved both by targetting interactions between these cytoplasmic factors and their receptors located in target membranes, and also by specific binding of the topogenic sequences to specific proteins integrated into the target membranes. Possible candidates for the latter are the protein of microsomal membranes that reacts with a photoreactive signal peptide to give a 45 kDa complex (Fig. 1), the secY gene product of the bacterial inner membrane, and receptors on the outer membranes of chloroplasts and mitochondria. Whether these aid translocation as well as recognition is not clear.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗