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Biomedical subjects

B Miller

Publications and source records attributed to B Miller.

At least 271 records · Page 15Linked to original sources
PubMed1990

Walker-Warburg syndrome with microtia and absent auditory canals.

Walker-Warburg syndrome is a lethal, autosomal recessive disorder characterized by anomalies of the central nervous system and eye. Typical findings include hydrocephalus, agyria, retinal dysplasia, cerebellar dysgenesis, anterior chamber dysgenesis, and encephalocele. Recently, the phenotypic spectrum has been expanded to include congenital muscular dystrophy. Two sibs with Walker-Warburg syndrome are reported. One sib had congenital glaucoma and hydrocephalus. The other sib had hydrocephalus, microtia, absent auditory canals, and pale retinas, barely within the phenotypic spectrum of the disorder. Elevation of muscle enzymes was consistent with the diagnosis of Walker-Warburg syndrome.

Abnormalities, Multiple↗
PubMed1990

Hypothesis: warfarin administered simultaneously with heparin infusion will prevent heparin-discontinuance associated coronary thrombosis.

Recent studies have evidenced an association between the time of heparin discontinuance and coronary artery reocclusion. Some investigators have concluded that inadequate heparinization was responsible, and further heparin infusion or an increase in dose would have been indicated. However, several investigators (Rao: Thrombosis Research 24:181-186, 1981; Marciniak and Gockerman: Lancet September 17:581-584, 1977; Fisken et al.: Lancet December 10: 1231, 1977; Conard et al.: Thrombosis Research 22:507-511, 1981; Kakkar et al.: Lancet January 12:103-104; Green: Lancet February 16:374, 375; Harborne and Nicolaides: Thrombosis Research 43:657-662, 1986; Bonen et al.: Thrombosis Research 27:123-124, 1982; Blomback et al.: Acta Physiologica Scandinavica 58:306-318, 1963; Holm et al.: Scandinavian Journal of Haematology 35:564-569, 1985; Andersson et al.: Thrombosis Research 34:333-340, 1984) have demonstrated that antithrombin III levels are reduced in patients on intravenous heparin. Both reduced antithrombin III levels and reduced rate of antithrombin inhibition of thrombin at the time of heparin discontinuance may increase the risk of coronary rethrombosis. If this theory is correct, increasing heparin infusion may exacerbate this risk. We propose an investigation that will provide evidence for or against the decreased antithrombin III theory, and in doing so, test an experimental therapy designed to prevent coronary reocclusion upon heparin discontinuance. In a randomized, placebo-controlled double-blinded study, we will determine whether simultaneous administration of warfarin with heparin initiation provides more time to increase antithrombin III levels and prevent coronary reocclusion upon heparin discontinuance, compared to heparin without warfarin therapy.

Antithrombin III↗
PubMed1990

Intrinsic potential for high fetal hemoglobin production in a Druz family with beta-thalassemia is due to an unlinked genetic determinant.

The mechanism for elevated production of fetal hemoglobin (Hb F) in a Druze patient with beta zero-thalassemia intermedia was investigated. Heterozygous family members exhibited normal Hb F levels, suggesting that the increase in gamma-gene expression in the propositus may be partly due to anemic stress. Erythroid progenitors of these family members cultured in vitro [burst forming units (erythroid); (BFUe)] showed elevated synthesis of Hb F, indicating the existence of a genetically determined intrinsic capacity for high Hb F production in this family. The propositus was found to be homozygous for a IVS2-position 1 mutation, on the background of Mediterranean haplotype I, which is not known to be linked to high Hb F production. Moreover, extensive molecular studies of the beta-globin gene cluster, including sequence analysis of the promoter regions of the gamma-globin genes, did not reveal any cis- actin mechanism that could account for the high Hb F production in the propositus. A young niece of the propositus with beta zero-thalassemia major was recently discovered, who was homozygous for the same beta-globin allele and haplotype as the propositus. However, unlike her uncle, she does not have a high Hb F level and presents with a severe clinical course. Her inability to produce high Hb F suggests that the genetic determinant for increased gamma-gene expression in the propositus is unlinked to the beta-globin gene cluster.

Adolescent↗
PubMed1990

Vaginal radiation brachytherapy to reduce central recurrence after radical hysterectomy for cervical carcinoma.

Seventeen (17%) of one hundred and two patients were treated with radiation brachytherapy (without external-beam therapy) to the proximal vagina to reduce the possibility of central pelvic recurrence following radical hysterectomy for cervical carcinoma. The 17 were considered to be at greater risk of developing recurrent cancer in the central pelvis because the cancer invaded halfway through the cervix; however, no lesions extended beyond the cervix, nor were metastases to lymph nodes present or surgical margins involved. The brachytherapy treatment was evaluated for prevention of central pelvis recurrence and for related complications. The 17 women treated with radiation brachytherapy were also compared with 74 patients who did not receive brachytherapy after radical hysterectomy because their cancers were smaller and did not invade halfway through the cervix. Both groups were similar with respect to age (41 and 40 years, respectively), weight (69.5 and 65.9 kg), operative characteristics, and the proportions of squamous cell carcinoma and adenocarcinoma. Recurrences have not been observed among the patients treated with brachytherapy during a mean follow-up of 39 months (range, 9-92 months). No complications were attributed to the brachytherapy. However, two patients with large tumors refused adjuvant brachytherapy and suffered central pelvic recurrences. Brachytherapy in selected patients following radical hysterectomy was safely administered and appeared to reduce the risk of central pelvic recurrence.

Adenocarcinoma↗
PubMed1990

Family caregivers and limitations in social activities.

Constriction of social and personal activities is one of the most frequently noted consequences of caring for a frail elder. This study analyzed the correlates of perceived limitations in social activities using data from a national sample of the frail elderly and their caregivers. Two research issues were addressed: 1) What differences in demographic, family, and caregiving attributes are associated with variation in perceived restricted social activities? and, 2) How does the process influencing restriction of social activities vary by family relationship of the caregiver? Higher levels of elder dependency and task demands were characteristic of those who reported social limitations, and daughters and wives were more likely to report such limitations than sons and husbands. Subjective assessment of time and task demands, however, were more important influences than objective caregiving activities for all family caregivers.

Aged↗
PubMed1990

Technological change and the medical technologist: a stress survey of four biomedical laboratories in a large tertiary care hospital.

Medical technologists from four clinical laboratories in a large teaching hospital were surveyed for their perceptions of occupational stress or job dissatisfaction concomitant with the advent of major technological and procedural change. Overall the data support the interpretation of excessive stress and job dissatisfaction. More than one-third (37.7%) of the laboratory personnel experienced psychological symptoms of occupational stress; 46.4% had experienced physical symptoms of stress. There was a marked and significant increase in reports of adverse effects among the group of laboratory workers subjected to the most extensive technological changes. Main components of the stress difference related to work overload, feelings of uncertainty in the face of new technology, lack of direction from supervisors and lack of influence on management. Age, type of shift worked and years of employment were associated with physical and psychological manifestations of stress. Implications and recommendations for laboratory workers, hospital administrators and educators are discussed.

Attitude of Health Personnel↗
PubMed1990

Pathogenesis of laser-induced choroidal subretinal neovascularization.

The early stages (1 day to 3 weeks) in the development of laser-induced choroidal subretinal neovascularization were studied in the monkey eye. Histopathology revealed that the intense laser beam disrupted the choroid/Bruch's membrane/retinal pigment epithelium (RPE) complex and initiated a repair process. Although all lesions received the same energy density, the initial choroidal wound varied among the lesions: in some, the necrotic choroid was surrounded by hemorrhagic retinal detachment with RPE denudation; in others, the necrotic choroid was surrounded only by minimal damage to the RPE monolayer. Formation of the choroidal wound was followed by an inflammatory response. Later, newly formed choroidal tissue filled the wound and continued to proliferate towards the subretinal space. RPE cells from the edges of the wound proliferated over the newly formed subretinal tissue and closed the wound. In lesions with a large area of damaged RPE, coverage of the wound was slow; fluid accumulated in the subretinal space, and the lesions demonstrated pooling of fluorescein on angiography (leaky lesions). In lesions with minimal damage to RPE monolayer, closure of the wound was rapid, and the proliferating choroidal tissue did not reach the subretinal space. There was no subretinal fluid accumulation and no pooling of fluorescein on angiography (nonleaky lesions). Our results indicate that both the amount of damage of the choroid/Bruch's membrane/RPE complex and the ability of RPE cells around the damaged area to proliferate and restore the continuity of the RPE layer determine the evolution of newly formed choroidal fibrovascular tissue into a subretinal membrane with or without pooling.

Animals↗
PubMed1989

Cough-cardiopulmonary resuscitation in the cardiac catheterization laboratory: hemodynamics during an episode of prolonged hypotensive ventricular tachycardia.

Cough-CPR, a deep rhythmic forceful cough repeated 30-60 times per minute, can be an effective resuscitative technique during emergencies occurring in the cardiac catheterization laboratory. We provide documented evidence on the potential of cough-CPR to maintain adequate systemic arterial blood pressure and consciousness during malignant ventricular arrhythmias, including the longest cough-CPR episode (75-90 sec), with continuous hemodynamics recorded. Results in three patients disclose that 1) mean arterial pressure during cough-CPR was 47-66% of nonarrhythmic baseline at a cough rate of 38-46% of normal sinus rhythm heart rate; 2) mean arterial pressure during hypotensive ventricular tachycardia was 17-60 mm Hg higher with than without cough-CPR; 3) at comparable diastolic pressures (33 vs. 31 mm Hg), systolic arterial pressure during cough-CPR was 40 mm Hg higher than basic CPR; and 4) consciousness can be maintained with cough-CPR during prolonged malignant ventricular arrhythmias. Thus cough-CPR can be a valuable adjunct in maintaining patient stability while definitive therapy for the malignant ventricular arrhythmia is administered.

Aged↗
PubMed1989

Hemorheological parameters in patients with gynecologic malignancies.

Thromboembolic events account for a significant number of complications during surgical and chemotherapeutic treatment for gynecologic malignancies. Besides changes in the hemostatic system, changes in hemorheological parameters facilitate initiation and promotion of thrombotic disease. We used a rheoaggregometer to determine erythrocyte aggregation and a capillary viscosimeter to evaluate plasma viscosity in patients with gynecologic malignancies at the time of primary diagnosis and during follow-up and compared the results to those for a normal control group. We found a significant elevation in plasma viscosity and erythrocyte aggregation as well as in fibrinogen and globulin concentrations in cancer patients. The extent of this rise was related to the tumor volume. Treatment with cisplatin, doxorubicin, and cyclophosphamide resulted in a further rise in erythrocyte aggregation which is attributed to a direct effect on the erythrocyte membrane. Thus, additional factors contributing to the risk of thrombosis in these patients were defined. Additional administration of rheologically active agents might improve the results of thrombosis prophylaxis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Cerebral hypoxic injury detected by Tc-HMPAO SPECT.

Single photon emission computed tomography of the brain with Tc-99m labeled hexamethylpropyleneamine oxime was used to evaluate a patient who suffered hypoxic cerebral injury. Hypoperfusion in the right parieto-occipital and left occipital regions was demonstrated on the SPECT images, while both the cranial CT and EEG failed to document the findings.

Adult↗
PubMed1989

Triphasic sharp waves in a patient with carcinomatous meningitis.

Subacute encephalopathy with an electroencephalographic (EEG) pattern of generalized periodic triphasic sharp waves occurred in an 80-year-old woman with autopsy proven carcinomatous meningitis. Meningeal carcinomatosis should be included within the differential (clinical) diagnosis of such an EEG pattern.

Adenocarcinoma↗
PubMed1989

Cardiac pathology in the hypertensive diabetic rat. Biventricular damage with right ventricular predominance.

The hypertensive-diabetic rat is a new small animal model of cardiomyopathy characterized by ventricular damage. To determine the extent of pathology in this model, quantitation of light microscopic changes in hearts from 15 hypertensive-diabetic rats and 15 age-matched controls was performed. The fraction of myocardium involved by interstitial fibrosis, myocyte necrosis, replacement fibrosis, vascular sclerosis and perivascular fibrosis was computed separately for right and left ventricles. Spontaneously dying as well as deliberately killed hypertensive-diabetic rats were studied. Spontaneously dying animals had higher systolic blood pressures compared with rats killed deliberately. Body weights were lower and lung weights higher in the former group. Left and right ventricular necrosis and fibrosis were increased in spontaneously dying compared with deliberately killed rats. The degree of right ventricular necrosis and fibrosis paralleled that in the left ventricle, but was, unexpectedly, several times greater in magnitude. Thus, quantitative histology in the hypertensive-diabetic rat reveals more cardiac necrosis and fibrosis, in either ventricle, from spontaneously dying animals compared with deliberately killed rats. This damage, coupled with major functional alterations in the viable myocardium, may lead to congestive heart failure or arrhythmia.

Animals↗
PubMed1989

Informed consent: procedure specific.

The Iowa Supreme Court recently set forth guidelines concerning informed consent. The authors discuss formulation of procedure specific surgical consent forms which comply with Iowa Code requirements.

Forms and Records Control↗