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Biomedical subjects

M T Holland

Publications and source records attributed to M T Holland.

9 recordsLinked to original sources
PubMed2001

Isolation and frontier molecular orbital investigation of bioactive quinone-methide triterpenoids from the bark of Salacia petenensis.

The crude dichloromethane bark extract of Salacia petenensis (Hippocrateaceae) from Monteverde, Costa Rica, shows antibacterial and cytotoxic activity. Bioactivity-directed separation led to the isolation of tingenone and netzahualcoyonol as the biologically active materials. Also isolated from the extract were 3-methoxyfriedel-2-en-1-one (a new natural product) and 29-hydroxyfriedelan-3-one. The structures of these compounds were elucidated on the basis of NMR spectral analysis. Molecular orbital calculations have been carried out using the semi-empirical PM3 and Hartee-Fock 3-21G ab initio techniques on the quinone-methide nortriterpenoids tingenone and netzahualcoyonol, as well as on the nucleotide bases adenine, guanine, cytosine, and thymine. The molecular orbital calculations suggest that a possible mode of cytotoxic action of quinone-methide triterpenoids involves quasi-intercalative interaction of the compounds with DNA followed by nucleophilic addition of the DNA base to carbon-6 of the triterpenoid.

Indolequinones↗
PubMed1995

Quantitative measurement of cutaneous perception in diabetic neuropathy.

To determine the diagnostic value of various cutaneous sensory modalities in diabetic neuropathy, we studied cutaneous perception at the dominant hallux of 113 subjects (32 normal healthy controls and 81 diabetic subjects). The cutaneous sensory perception tests included warm and cold thermal perception, vibration, touch-pressure sensation, and current perception testing (CPT). The sensitivity of each modality when specificity is held greater than 90% was as follows: warm = 78%, cold = 77%, vibration = 88%, tactile-pressure = 77%, 5-Hz CPT = 52%, 250-Hz CPT = 48%, and 2000-Hz CPT = 56%. Combination thermal and vibratory gave optimum sensitivity (92-95%) and specificity (77-86%). We conclude that vibratory and thermal testing should be the primary screening tests for diabetic peripheral neuropathy. Other modalities may be of use only in specific situations.

Adult↗
PubMed1995

Phospholipid and glutamic acid decarboxylase autoantibodies in diabetic neuropathy.

OBJECTIVE: To determine the prevalence and significance of phospholipid autoantibodies (PLAs) and glutamic acid decarboxylase (GAD) autoantibodies in the circulation of normal patients and diabetic patients with and without neuropathy. RESEARCH DESIGN AND METHODS: We measured PLAs in a total of 78 patients (a diabetic group with somatic or autonomic neuropathy [n = 40] another group without neuropathy [n = 38]), and GAD autoantibodies in a subset of 22 patients. RESULTS: PLAs are found in 2% of the general population. We found PLAs in 32% of the diabetic population without neuropathy, in 88% of those with neuropathy, in 55% of those with retinopathy, and in 25% of those with established nephropathy. The frequencies of immunoglobulins in the neuropathic group were: IgG = 78%, IgM = 33%, and IgA = 23%. There was no correlation between PLAs and microalbuminuria, macrovascular disease, fibrinogen, duration of diabetes, or neuropathy, but there was a strong correlation with total neuropathy score. Sera with high PLA IgG titers bound to the surface of neuroblastoma cells and inhibited cell growth. Antibodies to GAD65 were present in 32% and to GAD67 in 0% of patients. No titers of GAD65, GAD67, or the GAD65 ratio were associated with the degree of neuropathy of the presence of PLAs. CONCLUSIONS: PLAs occur frequently in the sera of patients with diabetes and correlate with the extent of neuropathy, suggesting a role for PLAs in the etiology thereof. The measurement of PLAs may constitute a marker for ongoing damage to nerves.

Analysis of Variance↗
PubMed1995

Nurse-physician collaboration and decision outcomes in transplant ambulatory care settings.

OBJECTIVE: This study examined the nature of nurse-physician collaborative practice as reflected in problems presented by transplant patients in telephone contacts with clinical nurse specialists (CNSs). DESIGN: Exploratory descriptive study. SAMPLE/SETTING: The sample consisted of 202 renal and renal-pancreas transplant recipients who telephoned nurses at the outpatient clinic of a tertiary care medical center. METHODS: Over a period of 6 weeks, using a data collection form, nurse specialists recorded the types and frequencies of problems described by transplant patients via telephone interaction and categorized the outcomes of decisions. RESULTS: Of the 437 calls, averaging 2.16 calls per patient, problems were classified as general questions (46%), medication related (32%), and clinical signs and symptoms (22%) such as fever, rejection, colds, and urinary tract infections. Decision outcomes (n = 354) categorized as independent or collaborative for problem resolution were: CNS only (80%), MD only (11%), and collaborative (9%). CONCLUSIONS: Resolution of 80% of patients' problems presented in telephone interactions shows that advanced practice nurses play a pivotal role in the delivery of care to outpatient transplant recipients. Independent decision making on the part of the nurse occurs within the context of ongoing collaboration and communication with physician colleagues.

Adolescent↗
PubMed1992

Diabetic neuropathies.

Diabetic neuropathy is a common complication of diabetes that may be associated both with considerable morbidity (painful polyneuropathy, neuropathic ulceration) and mortality (autonomic neuropathy). The epidemiology and natural history of diabetic neuropathy is clouded with uncertainty, largely caused by confusion in the definition and measurement of this disorder. We have reviewed various clinical manifestations associated with somatic and autonomic neuropathy, and we herein discuss current views related to the management of the various abnormalities. Although unproven, the best evidence suggests that near-normal control of blood glucose in the early years after diabetes onset may help delay the development of clinically significant nerve impairment. Intensive therapy to achieve normalization of blood glucose also may lead to reversibility of early diabetic neuropathy, but again, this is unproven. Our ability to manage successfully the many different manifestations of diabetic neuropathy depends ultimately on our success in uncovering the pathogenic processes underlying this disorder. The recent resurgence of interest in the vascular hypothesis, for example, has opened up new avenues of investigation for therapeutic intervention. Paralleling our increased understanding of the pathogenesis of diabetic neuropathy, refinements must be made in our ability to measure quantitatively the different types of defects that occur in this disorder. These tests must be validated and standardized to allow comparability between studies and more meaningful interpretation of study results.

Diabetes Mellitus↗
PubMed1977

Computer record keeping in a large rodent colony.

An automated information system was developed to aid in the record keeping of inbred rodent breeding colonies. The system had keyboard terminals in each breeding room linked to a local mini-computer for data collection, editing, and short-term storage; and a remote, large computer center for permanent storage and report generation. The system allowed an animal technician to record all the activities associated with an inbred rodent breeding colony such as recording births of litters, weanings, assignment of animals, disposition of animals, and health observations. The information collected was available in daily reports provided within 24 hours after observations were recorded; weekly compilations that summarized the daily events; and special reports such as pedigrees, which were available on request.

Animal Identification Systems↗
PubMedDate not supplied

NCTR computer systems designed for toxicologic experimentation. III. Breeding information system.

The Breeding Information System (BIS) facilitates management control of the breeding colony operation at the National Center for Toxicological Research (NCTR). Although this automated data handling system was initially intended to support Animal Husbandry the system's basic design, flexibility or reporting, data manipulation capabilities, and integration with other NCTR data collection systems provides BIS with capabilities that have application to other groups including the Plans and Programs and most scientific areas. This description of the System is in terms of its potential value to these diverse user groups.

Animal Husbandry↗