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Biomedical subjects

M Miller

Publications and source records attributed to M Miller.

At least 19 recordsLinked to original sources
PubMed1992

Phase III trial of cyclophosphamide versus cyclophosphamide, doxorubicin, and methotrexate in hormone-refractory prostatic cancer. A Hoosier Oncology Group study.

BACKGROUND: Between August 1984 and November 1989, the Hoosier Oncology Group conducted a Phase III study comparing cyclophosphamide (CTX) with cyclophosphamide, doxorubicin, and methotrexate (CAM) in patients with hormone-refractory metastatic prostatic cancer to determine whether the addition of doxorubicin and methotrexate to the cyclophosphamide regimen conferred any survival advantage. METHODS: One hundred three patients were registered and randomized, 99 were evaluable for response, and all were evaluable for survival results. All had histologically confirmed metastatic prostatic cancer and had not responded to hormonal therapy. Fifty-three patients received CTX alone, and 50 received CAM. Seventy-one patients (69%) had evaluable disease, and 32 (31%) had measurable disease. RESULTS: There were no complete responses and only four (13%) partial responses in the patients with measurable disease. There was no difference in overall survival time between the two treatment arms in either patients with a Karnofsky performance status (KPS) of 80-100 (median survival, 9.0 versus 9.5 months; P = 0.93) or in those with a KPS of 50-70 (median survival, 5.0 versus 6.0 months; P = 0.51). There was no difference in overall time to progression between the two treatment arms (median time to progression; 4.4 versus 6.2 months; P = 0.07). Toxicity was tolerable in both regimens. CONCLUSIONS: It was concluded that there was no survival advantage to CAM over CTX alone. New chemotherapeutic agents with greater activity against prostatic cancer must be identified.

Aged↗
PubMed1992

Pneumonia associated with Salmonella choleraesuis infection in swine: 99 cases (1987-1990).

Salmonella choleraesuis was isolated in pure or mixed bacterial cultures from 153 swine necropsied between Jan 1, 1987 and Dec 31, 1990. Pneumonia was seen in 99 of 109 swine from which this bacterium was isolated in the absence of other pathogenic bacteria. Pneumonia was seen more frequently than hepatitis, splenomegaly, or colitis. Pleuropneumonia that was grossly indistinguishable from the pleuropneumonia associated with Actinobacillus pleuropneumoniae was seen in 29 of 99 swine from which S choleraesuis was the only bacterium isolated.

Animals↗
PubMed1992

Usefulness of a CACA repeat polymorphism in genotype assignments in Duchenne/Becker muscular dystrophy.

RFLP analysis in Duchenne/Becker muscular dystrophy (D/BMD) has been limited by the lack of informative marker loci at the 3' end of the dystrophin gene. Recently a CACA repeat polymorphism was described in the 3' untranslated end of the dystrophin gene which we have found helpful in genotype assignments of D/BMD families when an RFLP approach is required. The CACA repeat marker has 2 common alleles (1 and 2) that are easily visualized by a nonradioactive PCR method followed by polyacrylamide gel electrophoresis. We present 2 families which demonstrate the use of this polymorphism. Since 35-50% of females are heterozygous, this locus is a useful marker in RFLP analysis of D/BMD families.

Base Sequence↗
PubMed1992

Photosynthetic electron-transfer reactions in the green sulfur bacterium Chlorobium vibrioforme: evidence for the functional involvement of iron-sulfur redox centers on the acceptor side of the reaction center.

The green sulfur bacterium Chlorobium vibrioforme was cultured in the presence of ethylene to selectively inhibit the synthesis of the chlorosome antenna BChl d. Use of these cells as starting material simplified the isolation of a photoactive antenna-depleted membrane fraction without the use of high concentrations of detergents. The preparation had a BChl alpha/P840 of 50, and the spectral properties were similar to those of preparations isolated from cells grown with a normal complement of chlorosomes. The membrane preparation was active in NADP+ photoreduction. This indicated that the fraction contained reaction centers with complete electron-transfer sequences which were then characterized further by flash kinetic spectrophotometry and EPR. We confirmed that cytochrome c553 is the endogenous donor to P840+, and at room temperature we observed a recombination reaction between the reduced terminal acceptor and P840+ with a t1/2 = 7 ms. Oxidative degradation of iron-sulfur centers using low concentrations of chaotropic salts introduced a faster recombination reaction of t1/2 = 50 microseconds which was lost at higher concentrations of chaotrope, indicating the participation of another iron-sulfur redox center earlier than the terminal acceptor. Cluster insertion using ferric chloride and sodium sulfide in the presence of 2-mercaptoethanol restored both the 50-microseconds and 7-ms recombination reactions, allowing definitive assignments of these centers as iron-sulfur centers. Following the suggestion of Nitschke et al. [(1990) Biochemistry 29, 3834-3842], we associate these two kinetic phases to back-reactions between P840+ and iron-sulfur centers FX and FAFB, respectively. The iron-sulfur cluster degradation and reconstitution protocols also led to inhibition and restoration of NADP+ photoreduction by the membrane preparation, providing unequivocal evidence for the function of the centers FX and FAFB in the physiological electron-transfer sequence on the acceptor side of the Chlorobium reaction center. At 77 K we observed a recombination reaction of t1/2 = 20 ms that we suggest occurs between Fx- and P840+. Degradation of the iron-sulfur clusters resulted in replacement of the 20-ms phase with a faster reaction of t1/2 = 80 microseconds that was most likely a recombination between the early acceptor A1- and P840+ or decay of 3P840. Analysis of the iron-sulfur centers in the preparation by EPR at cryogenic temperature supports the optical measurements. EPR signals originating from the terminal acceptor(s) were not observed following treatment of the membrane preparation by chaotropes, and a modified signal was restored following cluster reinsertion.(ABSTRACT TRUNCATED AT 400 WORDS)

Bacteria↗
PubMed1992

Enteric Clostridium perfringens infection associated with parvoviral enteritis in dogs: 74 cases (1987-1990).

Parvovirus infection was confirmed by fluorescent antibody staining of or viral isolation from specimens of small intestine in 181 (17%) of 1,110 dogs necropsied between July 1, 1987 and Dec 31, 1990. Clostridium perfringens was isolated from 74 (69%) of 108 dogs with parvovirus infection from which specimens of jejunum also had been obtained for culture of anaerobic bacteria. Gram-positive bacilli in association with focal to diffuse necrosis of the superficial portions of the villi were observed in histologic sections of specimens of small intestine from 56 (98%) of 57 dogs from which parvovirus and C perfringens had been identified. These findings indicate that C perfringens frequently proliferates in dogs with parvovirus infection.

Animals↗
PubMed1992

Analysis of the structure of photosystem I in cyanobacterial thylakoid membranes.

Using electron microscopy of negatively stained specimens, we have investigated the shape and degree of association of photosystem (PS) I complexes in cyanobacterial thylakoid membranes. When incubated at high concentrations of magnesium chloride (greater than 0.15 M), the PSI complexes form small ordered arrays in the membrane composed of monomeric complexes in a P1 square lattice of dimensions a = b = 11 nm. Averaged projections of the complex resemble those found for the purified PSI reaction centre after reconstitution (Ford, R.C, Hefti, A. and Engel, A. (1990) EMBO J. 9, 3067-3075). Some small differences in its shape are discussed, with particular reference to the differences in the polypeptide composition of the 2 preparations. We find that the complex remains in the monomeric form in the thylakoid membrane under all the conditions tested.

Cyanobacteria↗
PubMed1992

Sadistic and self-defeating personality disorder criteria in a rural clinic sample.

A sample of 176 outpatients at a mental health clinic in rural southern Georgia were rated for the presence or absence of the DMS-III-R sadistic and self-defeating personality disorder criteria. On the basis of these ratings, 48 patients met the criteria for sadistic (n = 14) and self-defeating (n = 41). Surprisingly, half of the patients who met the sadistic criteria also fulfilled the self-defeating criteria. A factor analysis failed to divide the criteria cleanly into sadistic and self-defeating subsets.

Adult↗
PubMed1992

Daughters caregiving for Hispanic and non-Hispanic Alzheimer patients: does ethnicity make a difference?

This study assessed Cuban-American Hispanic and White non-Hispanic daughters who were major caregivers for their mothers suffering from Alzheimer's Disease. Although patients in both ethnic groups did not differ in their level of cognitive and functional impairment, Cuban-American Hispanic patients were significantly more likely to be living in their daughters' homes while the White non-Hispanic patients resided in institutional settings. Caregivers were equivalent in their knowledge and utilization of community services, but Cuban-American daughters were significantly more aware of financial aid resources. Cuban-American patients were significantly more depressed than their White non-Hispanic counterparts with daughters showing similar but nonsignificant trends. The impact of cultural factors on caregiving is discussed.

Activities of Daily Living↗
PubMed1992

Application of a microbial sensor for determination of short-chain fatty acids in raw milk samples.

A microbial sensor system, based on the use of immobilized Arthrobacter nicotiana and an oxygen electrode, was applied to determine free short-chain fatty acids in raw milk samples and the result was compared with gas chromatography (GC) and a titrimetric method. The sensor response was linearly related to the concentration of short-chain fatty acids obtained by GC (n = 10, r = 0.92) and to the total concentration of free fatty acids obtained by titrimetric measurement (n = 10, r = 0.78). This result suggests that the present microbial sensor can selectively determine free short-chain fatty acids in raw milk samples and may be useful as a very fast detection method of rancidity in milk.

Animals↗
PubMed1992

Tuberculosis and AIDS: European and worldwide perspectives.

To examine the possible influence of AIDS and HIV infection on the epidemiology of tuberculosis in Europe and worldwide in the coming decades an analysis of the available data on the two diseases and on the transmission of the two infections in relation to the demographic structure of the population was conducted, including projections for up to the year 2025. Globally, the effects of the AIDS pandemic on the tuberculosis situation will probably be very serious, adding some 1.5 million new cases of tuberculosis annually by the year 2025 as a result of HIV infection. However, this effect for Europe in the year 2025 may be in the range of 15,000 additional cases only. The main factor determining the scale of aggravation of Tb is the age structure of the population infected, or at risk of being infected, with tubercle bacilli and HIV. Although the influence of HIV infection on tuberculosis in Europe may not be very high due to the fact that HIV infection involves mainly younger age groups it may, however, substantially postpone the elimination of tuberculosis from Europe. Therefore it seems necessary to monitor constantly all the changes in the epidemiological situation of both tuberculosis and AIDS/HIV.

AIDS-Related Opportunistic Infections↗
PubMed1992

Growth curves of Staphylococcus aureus, Candida albicans, and Moraxella osloensis in propofol and other media.

Propofol, 2,6 diisopropylphenol, in an emulsion formulation (Diprivan), has been associated with postsurgical infections caused by Staphylococcus aureus, Moraxella osloensis and Candida albicans. These organisms were individually inoculated into each of the following media: (1) the emulsion preparation of propofol, (2) Intralipid 10%, (3) pure 2,6 diisopropylphenol, and (4) trypticase soy broth (TSB). The organisms were incubated and subcultured hourly for eight hours at room temperature. Propofol supported the growth of all three organisms, but for S. aureus and M. osloenis, the growth rate was slower in propofol than in TSB (P less than 0.05). There was no difference between the growth rate of any organism in propofol than in Intralipid 10%. The authors conclude that propofol, in the emulsion formulation, supports bacterial growth and, therefore, must be prepared for administration in an aseptic manner. Also, by administering propofol soon after preparation, the risk of introduction of a significant inoculum to the patient will be reduced.

Candida albicans↗
PubMed1992

Carbon dioxide prevents pulmonary overcirculation in hypoplastic left heart syndrome.

Circulatory and metabolic homeostasis in patients with hypoplastic left heart syndrome is dependent on a delicate balance between systemic and pulmonary blood flow. Hypocarbia can result in a marked decrease in pulmonary vascular resistance accompanied by pulmonary overcirculation, systemic hypotension, metabolic acidosis, and death. This report illustrates that early and precise control of the arterial carbon dioxide tension using inspired carbon dioxide can be effective in preventing or treating instability arising during management of a patient with hypoplastic left heart syndrome.

Acidosis, Respiratory↗
PubMed1992

Myosin II distribution in neurons is consistent with a role in growth cone motility but not synaptic vesicle mobilization.

We have generated a polyclonal antibody against myosin II from a neuronally derived cell line in order to assess potential roles for myosin II in growth cone movement and synaptic transmission. The distribution of neuronal myosin II, in isolated cells as well as in tissues of the adult rat brain and spinal cord, was examined at the light microscopic and ultrastructural levels. In isolated neuroblastoma cells and dorsal root ganglion neurons, myosin II was found at the leading edge of growth cones, within neuritic processes and cell soma, and adjacent to the plasma membrane. The subcellular distribution of myosin II overlapped significantly with that of both actin and single-headed myosin I. These results implicate both myosin I and myosin II as molecular motors required for neurite elongation and growth cone motility. An exclusive postsynaptic distribution of myosin II in neurons of the mature central nervous system suggests that myosin II cannot play a role in the mobilization of synaptic vesicles, but could participate in synaptic plasticity.

Animals↗
PubMed1992

Neuropsychological performance among agricultural pesticide applicators.

To assess the potential effects on neuropsychiatric performance of chronic occupational exposure to organophosphate insecticides, we performed a prospective longitudinal study of a cohort of apple orchard pesticide applicators and a comparison cohort of beef slaughter-house workers. The study group consisted of 49 applicators and 40 comparison subjects who completed both an initial evaluation (preseason) prior to the onset of the approximately 6-month pesticide spraying season and a follow-up evaluation (postseason) about 1 month following the end of spraying season. The applicator cohort had a greater number (n = 22, 45%) of individuals who identified primary preference for Spanish-language testing than did the comparison cohort (n = 5, 13%). Stratification by language preference revealed no significant differences in background characteristics between the two cohorts, except for fewer years of education in the Spanish-language preference applicators versus control subgroups (5.0 +/- 3.1 vs 7.8 +/- 3.7 years, respectively). After controlling for language preference, there were no statistically significant differences between the applicators and control cohorts on neuropsychological subtests of the computerized test battery. Preseason baseline performance on individual tests was a significant predictor of postseason test performance. After controlling for baseline performance, the only statistically significant exposure related across-season changes in neuropsychological performance was for one subtest (Symbol Digit Substitution) and was confined to the Spanish language preference subgroups, with worse adjusted postseason performance among applicators versus controls (P = 0.001). This study found no clear evidence of clinically significant decrements in neuropsychological performance following one 6-month season of pesticide exposure in a cohort of applicators who were felt to have generally low, intermittent, and well-controlled organophosphate exposures.

Adult↗
PubMed1992

Organophosphate pesticide exposure in a group of Washington State orchard applicators.

As part of a study to investigate the potential for organophosphates to cause chronic neurologic sequelae, we assessed the pesticide exposure experience of a group of Washington State apple orchard applicators. Seasonal monitoring of cholinesterase activity for 48 regular organophosphate applicators and a control group of 40 slaughterhouse workers was performed. A subset of the pesticide applicators participated in an in-depth exposure assessment. This involved observation of spraying activities during 1 spray day, as well as cholinesterase monitoring and dermal exposure assessment using a fluorescent tracer in the pesticide formulation. Comparison of seasonal red blood cell cholinesterase change in pesticide workers according to exposure level, characterized by frequency of pesticide spraying and protective equipment use, showed lower cholinesterase levels among higher exposed groups compared to lesser exposed groups. In-depth exposure assessment revealed exposure primarily on the head and hand regions. Subclinical changes (less than 15% inhibition) in red cell cholinesterase correlated well with dermal exposure calculations. This study suggests that cholinesterase monitoring may be a useful biological marker for even subclinical organophosphate pesticide effects.

Agricultural Workers' Diseases↗
PubMed1992

Effects of essential hypertension and antihypertensive medications on sweat formation.

OBJECTIVE: Sweat volume and ionic composition depend to a large extent upon the cytosolic free calcium level in secretory sweat cells and sodium and potassium transport in the reabsorptive sweat duct. Since essential hypertension and its treatment with antihypertensive drugs is likely to be associated with altered cellular ionic regulation, the objective of this research was to explore sweat formation and sweat parameters in hypertensive and normotensive subjects. DESIGN: Black and white hypertensive and normotensive subjects of both genders were studied. Essential hypertensives were on or off antihypertensive medication. METHODS: Pilocarpine iontophoresis was used to induce sweat in a 5-cm2 area of the middle forearm. Sweat was analyzed for volume, sodium and potassium concentrations. RESULTS: Females demonstrated lower sweat volumes after pilocarpine stimulation than males. Untreated hypertensive white males exhibited a higher pilocarpine-induced sweat volume and sweat sodium excretion than normotensive white males, whilst hypertensive white males on antihypertensive medication showed a lower sweat volume and sweat sodium excretion than both normotensive white males and untreated essential hypertensive white males. Although untreated hypertensive white females did not show significant alterations in sweat parameters, treated hypertensive white females exhibited lower sweat volume and sweat sodium excretion than both the normotensive and untreated essential hypertensive white females. These hypertension and drug related alterations were not present in hypertensive black males and females. CONCLUSIONS: The results are consistent with the heterogeneous nature of essential hypertension and the diversity of the response to antihypertensive therapy. They suggest that the effect of antihypertensive medication on sweat formation is mediated through cytosolic free calcium.

Adult↗
PubMed1992

Coronary artery fistulas: a review and case study.

Coronary artery fistula is a congenital abnormality that can present with a variety of cardiovascular complications. This article presents a patient with a coronary artery fistula outlining the pathophysiology and course of hospitalization, with particular emphasis on nursing management of a patient with coronary artery fistula.

Adult↗