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Biomedical subjects

D A Allen

Publications and source records attributed to D A Allen.

67 records · Page 4Linked to original sources
PubMed1977

Numerical taxonomy of heavy metal-tolerant bacteria isolated from an estuary.

A total of 230 strains of metal-tolerant bacteria from water and sediment samples collected in Chesapeake Bay were isolated on a medium containing cobalt, lead, mercury, or molybdenum. In addition, a set of 71 cultures were simultaneously isolated on glucose tryptone yeast extract agar medium without metals. Twenty-three reference strains were also included in the numerical taxonomy study of these bacteria, bringing the grand total of strains examined to 324. All strains were examined for 112 biochemical, cultural, morphological, and physiological characters. The taxonomic data obtained were analyzed by computer and the simple matching (SSM) and Jaccard (SJ) coefficients were calculated. Clustering achieved by unweighted average linkage is presented and, from sorted similarity matrices and dendrograms, 294 strains, i.e., 97% of the total, were recovered in 12 phenetic groups defined at the 75 to 80% similarity level. Among the strains there were nine phena presumptively identified as Bacillus, Erwinia, Mycobacterium, Pseudomonas, and coryneforms. From the results of the taxonomic study, it is concluded that metal tolerance in estuarine water and sediment bacteria occurs among a restricted range of taxa distributed throughout the estuarine environment.

Actinomycetales↗
PubMed1976

Linguistic performance in vulnerable and autistic children and their mothers.

The authors studied the language patterns of schizophrenic mothers and their 4-year-old children, and compared them with the speech of normal mothers and children and normal mothers with autistic children. They found that children of schizophrenic mothers showed lags in language development and language distortions less severe than but in some ways similar to those seen in autistic children. Schizophrenic mothers were more likely to produce more deficient and/or distorted language in interactions with their children. Mothers of autistic children produced language that was equal to or above that of mothers of normal children on most parameters and adjusted their language to the chronological rather than the linguistic age of the child.

Autistic Disorder↗
PubMedDate not supplied

Peripartum cardiomyopathy: a case report.

Peripartum cardiomyopathy (PPCM) is a relatively rare form of acute heart failure. Onset is from the last trimester of pregnancy to 5 months postpartum. Diagnosis is made by excluding other causes of acute heart failure, such as infections or toxins, and by determining that the patient does not have an underlying cardiac problem that has been unmasked by pregnancy. Diagnosis in the last trimester is complicated by the fact that the early symptoms of this disorder may mimic the symptoms of normal pregnancy. PPCM must be considered in any patient who presents with new onset peripheral edema, dyspnea on exertion, or paroxysmal nocturnal dyspnea during late pregnancy or up to 5 months postpartum. Limited studies suggest that early and aggressive therapy is associated with a better outcome. Therapy is directed toward decreasing preload and improving cardiac function. Return of cardiac size to normal is associated with a better prognosis than continued cardiomegaly.

Acute Disease↗
PubMedDate not supplied

Dose optimization of nonionic contrast agent in dynamic computed tomography scanning of the abdomen and pelvis.

A prospective, randomized study was performed to examine the image quality of varying reduced doses of an intravenous (IV) nonionic contrast agent (ioversol, 320 mg/ml organically bound iodine) compared with the quality obtained using the maximum permissible dose (150 ml) of the same agent. Forty-five patients referred for abdominal-pelvic computed tomography (CT) scan were randomized into five groups to receive contrast doses equivalent to 100, 75, 65, 50, or 30% of 150 ml of contrast agent. The images were scored for diagnostic image quality in eight anatomical regions of interest and, in addition, quantitative analysis of density measurements were performed in the abdominal aorta and inferior vena cava. There was no statistically significant difference in either image quality, in any anatomical region, or in vascular density measurements between the group receiving 100% and the group receiving 75% of 150 ml of nonionic contrast agent. Patients receiving 65% and lower doses demonstrated a statistically significant decrease in enhancement, although all scans were diagnostically adequate. This study demonstrates that dynamic abdominal and pelvic CT scans obtained using a reduced dose of nonionic IV contrast agent are equivalent in diagnostic image quality compared with those scans obtained with the higher permissible dose of the same agent.

Adult↗
PubMedDate not supplied

Concerns of children with a chronic illness: a cognitive-developmental study of juvenile diabetes.

Chronically ill children become increasingly able to understand their illnesses as they develop intellectually. But cognitive development also brings the ability to grasp the meaning of a poor prognosis or functional limitations, which may take an emotional toll on the youngster. We studied this problem in a sample of children with insulin-dependent diabetes. Those who had more advanced disease concepts were more worried about their diabetes. Children saw their parents as worried primarily about current management of the disease, suggesting that youngsters' concerns about the future were difficult to discuss at home. There is a need for clinicians and parents to integrate emotional support into the education and management of chronically ill children.

Adaptation, Psychological↗
PubMedDate not supplied

Gracilis or semitendinosus myopathy in 18 dogs.

The clinical findings in 18 dogs with gracilis (n = 17) or semitendinosus (n = 1) myopathy are described. Each dog had a similar hind-limb gait abnormality characterized by a shortened stride with a rapid, elastic medial rotation of the paw, internal rotation of the hock and external rotation of the calcaneus [corrected] and internal rotation of the stifle during the mid-to-late swing phase of the stride. Medical management prior to or in lieu of surgery was attempted (n = 8) with no apparent response. Fifteen dogs had one or multiple surgical procedures. Although transection, partial excision, or complete resection of the affected muscle resulted in resolution of lameness following surgery, lameness recurred six weeks to five months (mean, 2.5 months; median, two months) following surgery. Adjunctive medical treatment did not prevent recurrence. Variable replacement of the affected muscle with fibrous connective tissue (predominantly along the caudolateral border of the muscle) was evident grossly, and replacement of myofibers with fibrous connective tissue was confirmed histologically. A definitive etiology could not be established.

Animals↗