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Biomedical subjects

Ann Abraham

Publications and source records attributed to Ann Abraham.

8 recordsLinked to original sources
PubMed2006

Characterization of polar brevetoxin derivatives isolated from Karenia brevis cultures and natural blooms.

Several novel brevetoxin derivatives were isolated and identified in Karenia brevis cultures and natural blooms by using solid phase extraction (SPE) and LC/MS(MS) techniques. These analogs were more polar compared with previously described brevetoxins, and were poorly extractable by conventional non-polar solvent (chloroform) partitioning. Brevetoxin analogs were structurally confirmed as hydrolyzed (open A-ring) forms of brevetoxins PbTx-1, PbTx-7, PbTx-2, and PbTx-3, and of oxidized PbTx-1 and PbTx-2. Some of these open A-ring derivatives were in greater abundance than their non-hydrolyzed counterparts. All were in much greater abundance in bloom water filtrate compared with cell-rich fractions. Open A-ring compounds were cytotoxic in mouse neuroblastoma (N2a) cell assay. In the K. brevis bloom-exposed Eastern oyster, brevetoxin metabolites with opened A rings were identified (e.g., open-ring cysteine-PbTx conjugates), contributing to their overall toxin burden.

Animals↗
PubMed2004

Lack of communication affects the care of patients and families.

The Health Service Ombudsman publishes reports of complaints investigated in the NHS. Poor communication was a feature of the following three cases. In the first, consent to a procedure was not obtained. In the second, failure to respond to a complaint added to a bereaved family's distress. In the final example, nursing teams failed to communicate in the interests of a patient.

Communication Barriers↗
PubMed2003

Inadequate nursing care and the failure to keep adequate records.

Lessons can often by learned by studying the outcomes of complaints made to the NHS by patients. We look at three recent investigations conducted and published by the Health Service Ombudsman. The first and second relate to poor care and lack of communication, and the third to care of a patient's diabetes and epilepsy in hospital and failure to record an outpatient consultation.

Clinical Competence↗
PubMed2003

Poor systems and staffing problems led to poor patient outcomes.

The office of the Health Service Ombudsman regularly publishes reports of complaints investigated by its assessors. The cases presented here relate to failures of nursing care: some of the problems were found to be the result of inadequate staffing and training, others were due to poor documentation, lack of staff accountability and inadequate organisation.

Humans↗
PubMed2002

Preparation of irreversibly sickled cell beta-actin from normal red blood cell beta-actin.

We have previously demonstrated that an oxidative change, the formation of a disulfide bridge between two cysteine residues, in the membrane protein beta-actin is primarily responsible for locking the irreversibly sickled red blood cells (ISCs) of sickle cell anemic patients into the sickle shape. To support studies on biological and chemical characterization of the oxidized beta-actin and pharmacological research toward the reversal of the oxidation, we attempted to prepare oxidized beta-actin from normal red blood cell (RBC) beta-actin by a chemical reaction, expecting a product equivalent to that found in ISCs. 5,5'-Dithiobis(2-nitrobenzoic acid) (DTNB, or Ellman's reagent) was used for the oxidation. We proved the absence of accessible sulfhydryl groups in the oxidized product using liquid chromatography (LC) with both UV and fluorescence detection. Polymerization assays indicated that the chemically produced ISC actin demonstrated the same kinetics as ISC actin obtained from patients with sickle cell disease. The effect of the oxidation could be reversed by the use of the reducing agent tris(carboxyethyl)phosphine (TCEP).

Actins↗
PubMed2002

Elevated plasma gamma-aminobutyric acid (GABA) levels in autistic youngsters: stimulus for a GABA hypothesis of autism.

BACKGROUND: Autistic Disorder is an early-onset developmental disorder with severe lifelong impact on social functioning, communication, and behavior. There is currently no marker or cure. The pathophysiology and etiology are obscure. Evidence for abnormal gamma-aminobutyric acid (GABA) function in Autistic Disorders is limited. A few case-reports and small studies have reported differences in GABA levels in plasma, platelets, and urine, compared to controls. Further studies on abnormalities of GABA function in Autistic Disorder are warranted. MATERIAL/METHODS: Plasma GABA levels were measured using a new and sensitive technique, based on gas chromatography/mass spectrometry, in a small group of youngsters with Autistic Disorder and Attention-Deficit/Hyperactivity Disorder. Participants were outpatients between ages 5-15, satisfying modern criteria for these disorders. RESULTS: Elevated plasma GABA levels were found in youngsters with Autistic Disorder. Psychotropic medications did not seem to affect plasma GABA levels in this study. Plasma GABA levels decreased with age. CONCLUSIONS: Elevated plasma GABA levels may be a biochemical marker of Autistic Disorder. This study supports the hypothesis that GABAergic mechanisms play a role in the etiology or pathophysiology of Autistic Disorder. However, the hypothesis remains unspecified owing to lack of research. Future studies on the clinical associations of seizure disorders, mood disorders, and catatonia in autistic people may provide the necessary data to formulate a coherent theory of GABA dysfunction in Autistic Disorder. More trials of medication with known or suspected effects on GABA function are warranted.

Adolescent↗