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Biomedical subjects

M Miller

Publications and source records attributed to M Miller.

At least 505 records · Page 28Linked to original sources
PubMed1991

Knowledge and beliefs about cancer in a socioeconomically disadvantaged population.

Americans living in poverty experience a higher incidence of and greater mortality from cancer than the nonpoor. At least 50% of the difference in mortality is believed to be due to delay in diagnosis, although risk-promoting lifestyles and behaviors also contribute to decreased survival. A potential exacerbating factor among the poor is inadequate information and knowledge about cancer and its treatment. Interviews were conducted with 128 cancer patients from a socioeconomically disadvantaged population to assess knowledge of cancer and its treatment and to evaluate care-seeking behaviors. Results indicated that although patients relied primarily on their physicians for information about their disease and treatment, a number of misconceptions regarding cancer existed in this population. Notably, nearly 50% of the patients surveyed either denied or did not know that smoking was related to the development of cancer. Additionally, patients frequently reported inappropriate care-seeking behaviors when asked to respond to a series of common disease-related signs or symptoms. These findings suggest that misinformation and misconceptions regarding cancer and its treatment among patients in this sample may contribute to inappropriate care-seeking behaviors.

Consumer Behavior↗
PubMed1991

The gene encoding rat nuclear pore glycoprotein p62 is intronless.

Glycoproteins of the nuclear pore complex are thought to play an important role in the transport of regulatory proteins and ribonucleoproteins across the nuclear envelope. However, the genetic elements and signals that control the expression of nuclear pore glycoproteins are poorly understood. To study the transcriptional regulation of mammalian nuclear pore glycoprotein biosynthesis, we have isolated the gene coding for the major rat nuclear pore glycoprotein p62. The p62 gene consists of a 2941-base pair region that is linear with the full length p62 cDNA with no intervening sequences. Quantitative Southern analysis revealed that the gene is present in single copy. The p62 gene encodes a 525-amino acid open reading frame that directs the synthesis of the 62-kDa pore glycoprotein in vitro and in transfected cultured cells. The 5'-flanking region contains two potential transcription start sites; primer extension analysis revealed that the furthest upstream site is preferentially used in vivo. When linked to a reporter gene, the 5'-flanking region of the p62 gene serves as an active promoter.

Animals↗
PubMed1991

Platelet aggregation in hyperapobetalipoproteinemia.

Hyperapobetalipoproteinemia (HyperapoB) is a lipid disorder characterized by premature coronary disease, although the mechanisms have not been elucidated. Because abnormalities in platelet function may represent an enhanced susceptibility to coronary thrombosis, the aggregability of platelets was examined in hyperapoB subjects. Compared to controls, there were no significant differences in either platelet lipid composition or in aggregation to epinephrine, ADP, or collagen. In contrast to other dyslipidemias, platelet function does not appear to be abnormal in this well defined lipid disorder.

Adult↗
PubMed1991

x121: a localized maternal transcript in Xenopus laevis.

We describe the cloning and characterization of a partial cDNA, x121, that represents an RNA, which is localized in the animal hemisphere of Xenopus oocytes. This RNA is also detected in an animal to vegetal gradient during early cleavage stages. The x121 RNA titer decreases from fertilization through the gastrula stage, after which it is not detectable on northern blots. The amino acid composition of the x121 conceptual protein derived from cDNA sequencing reveals a large number of acidic residues similar in distribution to proteins that function as transcriptional activators.

Amino Acid Sequence↗
PubMed1991

Impaired activation of skeletal muscle glycogen synthase in non-insulin-dependent diabetes mellitus is unrelated to the degree of obesity.

Twenty-five newly presenting, untreated, white, non-insulin-dependent diabetic (NIDDM) subjects were studied within 72 hours of diagnosis. They were allocated to three groups according to their body mass index [BMI] (lean BMI less than 25.0, n = 9; overweight BMI 25.0 to 30.0, n = 6; obese BMI greater than .30.0 kg/m2, n = 10). All three groups exhibited equivalent hyperglycemia. Eleven normal control subjects were also studied. The degree of activation of skeletal muscle glycogen synthase (GS) was used as an intracellular marker of insulin action, before and during a 240-minute insulin infusion (100 mU/kg/h). Fractional GS activity did not increase in the lean (change, -0.9 +/- 3.3%), the overweight (-1.9 +/- 2.7%), or the obese (+2.2 +/- 1.6%) NIDDM subjects during the insulin infusion and was markedly decreased compared with the control subjects (change, +14.6 +/- 2.4%, all P less than .001). Glucose requirement was also significantly decreased in all three NIDDM groups (103 +/- 23 v 81 +/- 14 v 53 +/- 14 mg/m2/min, respectively) compared with the control subjects (319 +/- 18 mg/m2/min, all P less than .001). There was a significant negative correlation with BMI (r = -.51, P less than .01), but the difference in glucose requirement between the lean and obese NIDDM groups was not significant. Muscle GS activity at the end of the euglycemic clamp correlated with glucose requirement (r = .53, P less than .001), and a similar correlation was observed between the insulin-induced change in muscle GS activity from basal and glucose requirement (r = .47, P less than .005).(ABSTRACT TRUNCATED AT 250 WORDS)

3-Hydroxybutyric Acid↗
PubMed1991

Enalapril improves albuminuria by preventing glomerular loss of heparan sulfate in diabetic rats.

Angiotensin converting enzyme (ACE) inhibitors, particularly enalapril and captopril, have been shown to decrease proteinuria in diabetic animals and human subjects. Since heparan sulfate proteoglycan confers a negative charge on the glomerular basement membrane, and either decreased synthesis or loss of this charge causes albuminuria in diabetic animals, we examined the possibility that enalapril prevents albuminuria through glomerular preservation of heparan sulfate in long-term diabetic rats. A total of 22 male Wistar rats were used in the study. Diabetes was induced in 15 rats by a single intraperitoneal injection of streptozotocin (60 mg/kg). The remaining 7 rats received buffer. One week following induction of diabetes, 8 diabetic rats were allowed to drink tap water containing enalapril at a concentration of 50 mg/liter; the remaining 7 diabetic and 7 nondiabetic rats were given only tap water. The drug treatment was continued for 20 weeks. Systolic blood pressure and 24-hr urinary excretion of albumin were measured at 2, 8, 16, and 20 weeks. At the end of 20 weeks, all rats were killed, kidneys were removed, and glomeruli were isolated by differential sieving technique. Total glycosaminoglycan and heparan sulfate synthesis was determined by incubating glomeruli in the presence of [35S]sulfate. Characterization of heparan sulfate was performed by ion-exchange chromatography. Systolic blood pressures were significantly lower in enalapril-treated diabetic rats compared to untreated diabetic rats. Diabetic glomeruli synthesized less heparan sulfate than glomeruli from nondiabetic rats. Also, glomerular heparan sulfate content of diabetics was significantly lower than that of nondiabetics. Further characterization of heparan sulfate showed that the fraction eluted with 1 M NaCl was significantly lower and the fraction eluted with 1.25 M NaCl significantly higher in diabetic than in normal rats. Enalapril treatment normalized not only glomerular synthesis and content but also various fractions of heparan sulfate in diabetic rats. Diabetic rats excreted increased quantities of heparan sulfate and albumin than nondiabetic rats. Enalapril therapy prevented both these increases in diabetic rats. These data suggest that enalapril treatment improves albuminuria through preservation of glomerular heparan sulfate and prevention of its urinary loss in diabetic rats.

Albuminuria↗
PubMed1991

Klippel-Trenaunay-Weber syndrome with recurrent pulmonary embolism.

A man with Klippel-Trenaunay-Weber syndrome had worsening pulmonary hypertension secondary to recurrent multiple pulmonary embolism despite anticoagulation. Pulmonary thromboendarterectomy was done. However, the patient expired 10 days after surgery due to another bout of pulmonary embolism from his right arm or right chest wall.

Humans↗
PubMed1991

A cluster of male pseudohermaphrodites with 5 alpha-reductase deficiency in Papua New Guinea.

We report a cluster of male pseudohermaphrodites from the Simbari Anga linguistic group in the Eastern Highlands of Papua New Guinea. These subjects are born with a rudimentary clitoral-like penis and pseudovaginal perineoscrotal hypospadias. At puberty, the penis enlarges with concurrent growth of pubic and axillary hair and significant muscular development. There is significant facial hair, but it is less than that of their normal male siblings or other male relatives. Plasma collected from four adult subjects revealed elevated plasma testosterone levels, low to low normal dihydrotestosterone levels, and elevated testosterone/dihydrotestosterone ratios. All subjects had high urinary aetiocholanolone/androsterone ratios, and C19 and C21 5 beta/5 alpha metabolite ratios. Decreased 5 alpha-reductase activity was demonstrated in fibroblasts cultured from genital skin. The data indicate a phenotypic and biochemical profile similar to patients studied in the Dominican Republic, except for a greater abundance of facial and body hair. The phenotypic variability, as pertains to facial and body hair, may be related to differences in familial expression, as well as the degree of enzyme deficiency. Infants, thought to be females at birth, were reared as girls until puberty in a society practising one of the strictest gender segregations known. At puberty, these 'girls' were discovered to be boys, and a switch of gender roles was instituted. Recently, however, some Muniri, Dunkwi and northern Simbari hamlets recognize these individuals as male in infancy and rear them as boys, calling them 'kwalatmala' to distinguish them from normal males, accepting them as an intersex destined to occupy male adult roles.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1991

The effect of sulphonylurea therapy on skeletal muscle glycogen synthase activity and insulin secretion in newly presenting type 2 (non-insulin-dependent) diabetic patients.

Ten newly presenting, Type 2 (non-insulin-dependent), Caucasian diabetic patients were studied before and after 8 weeks treatment with the sulphonylurea gliclazide, and in parallel 13 similar patients were studied before and after 8 weeks treatment with diet alone. Eight non-diabetic subjects were also studied. Insulin action was assessed by measuring activation of skeletal muscle glycogen synthase (GS) prior to and during a 4-h hyperinsulinaemic euglycaemic clamp (100 mU kg-1 h-1). Fasting plasma glucose (+/- SE) and glycosylated haemoglobin decreased to a greater extent in the gliclazide treated patients (fall of 6.2 +/- 0.7 vs 2.1 +/- 0.5 mmol l-1, p less than 0.005 and 4.7 +/- 0.5 vs 2.1 +/- 0.5%, p less than 0.005). This was accompanied by an increase in fasting serum insulin concentrations in the gliclazide treated patients (7.0 +/- 1.3 to 10.1 +/- 1.1 mU l-1, p less than 0.005), but no change in the diet treated patients. Fractional GS activity did not increase during the clamp at presentation in either treatment group (change +2.9 +/- 1.8 and -1.5 +/- 1.9%, respectively) whereas it increased markedly in the control subjects (+16.4 +/- 3.4%, both p less than 0.001). After 8-week treatment there was a significant increase in GS activity during the clamp in the patients receiving gliclazide (+6.9 +/- 2.7%, p less than 0.05), but no change in GS activity in the patients on diet alone (+0.5 +/- 1.4%). The difference in post-treatment muscle insulin action was significant (p less than 0.05). There was no correlation between the degree of improvement in metabolic control and the improvement in response of GS to insulin in the gliclazide treated patients (r = -0.06), suggesting a possible direct drug effect on skeletal muscle. Glucose requirement during the clamp at presentation was markedly lower in both treatment groups than in the non-diabetic subjects (gliclazide 2.1 +/- 0.3, diet 2.0 +/- 0.6 vs 7.8 +/- 0.4 mg kg-1 min-1, both p less than 0.001), and despite a marked improvement in both groups after treatment (4.3 +/- 0.4 and 3.1 +/- 0.5 mg kg-1 min-1, both p less than 0.001) remained lower than in the non-diabetic subjects (p less than 0.001).(ABSTRACT TRUNCATED AT 400 WORDS)

Blood Glucose↗
PubMed1991

Comparison of the effects of several potassium-channel openers on rat bladder and rat portal vein in vitro.

1. The ability of several K-channel openers to inhibit KCl-induced contractions of rat bladder detrusor and spontaneous mechanical activity in rat portal vein was examined. 2. Lemakalim, pinacidil, Ro 31-6930, RP 49356, P1060 and S 0121 dose-dependently relaxed rat detrusor, precontracted with 20 mM KCl. With the exception of pinacidil, concentrations of these agents below 30 microM did not inhibit 80 mM KCl-included contractions. Pinacidil (10 microM) produced a small, but significant (P < 0.05) relaxation of 80 mM KCl-induced mechanical activity. Minoxidil sulphate and BRL 38226 produced some relaxation of 20 mM but not 80 mM KCl-induced contractions. 3. Glibenclamide (0.3-3 microM) antagonized the relaxant effects of lemakalim, pinacidil, Ro 31-6930, RP 49356, P1060 and S 0121 in a competitive manner (pA2 values 6.3-6.6). The effects of minoxidil sulphate and BRL 38226 were fully antagonized by 3 microM glibenclamide. 4. Lemakalim, pinacidil, S 0121, BRL 38226 and minoxidil sulphate were each approximately 8 times more potent as inhibitors of the spontaneous contractions of rat portal vein than KCl-induced contractions of the rat detrusor. Minoxidil sulphate was approximately 30 times more potent in the rat portal vein than in the bladder. This may indicate that either minoxidil sulphate is acting at different recognition sites in these two tissues, or that this compound has an additional mechanism of action in the portal vein. 5. With the exception of minoxidil sulphate, all the compounds tested stimulated 86Rb efflux and 42K efflux from preloaded rat detrusor strips. The stimulated 86Rb efflux was qualitatively but not quantitatively similar to the stimulated 42K efflux. Minoxidil sulphate stimulated 42K efflux from rat portal vein but not from rat bladder. 6. It is concluded that all the compounds tested cause relaxation of rat detrusor predominantly by Kchannel opening. Selectivity for bladder rather than vascular smooth muscle was not shown by any compound.

Animals↗
PubMed1991

Effects of intravitreal dexamethasone on concentration of intravitreal vancomycin in experimental methicillin-resistant Staphylococcus epidermidis endophthalmitis.

Intravitreal corticosteroids in the treatment of bacterial endophthalmitis remain controversial. We utilized an experimental rabbit model of methicillin-resistant Staphylococcus epidermidis endophthalmitis (i) to calculate the intravitreal vancomycin concentration in rabbit eyes receiving intravitreal vancomycin alone or in combination with intravitreal dexamethasone and (ii) to determine whether an intravitreal steroid has any effect on intravitreal vancomycin levels. All right eyes were infected and all left eyes were uninfected. The rabbits were divided into two treatment groups: (i) 32 eyes (group I) were injected with intravitreal vancomycin, 1.0 mg (0.1 ml); (ii) 32 additional eyes (group II) were injected with intravitreal dexamethasone, 400 micrograms (0.1 ml), in addition to vancomycin. Measurement of intravitreal vancomycin concentration was performed following sacrifice, utilizing a microbiologic agar diffusion assay. Analyses of intravitreal vancomycin concentrations were performed by using model-independent parameters, with area under the concentration-time curves derived by trapezoidal approximation. The intravitreal vancomycin concentration was significantly lower in both uninfected and infected group II eyes (P less than 0.002). Analysis of intravitreal vancomycin concentration-time relationships was performed by using a nonlinear least-squares regression program; data best fit a one-compartment model. In addition, no vancomycin-dexamethasone interaction could be demonstrated. The reduced level of intravitreal vancomycin in the presence of intravitreal dexamethasone may have important clinical implications.

Animals↗
PubMed1991

The nuclear-cytoplasmic distribution of the Xenopus nuclear factor, xnf7, coincides with its state of phosphorylation during early development.

We describe the characterization in Xenopus laevis of a nuclear protein, xnf7, which is first detected in the oocyte GV and is eventually enriched in nuclei of cells of the adult brain. Previous studies have shown that this protein contains zinc-finger-like structures and acidic domains typical of transcriptional activators, and is phosphorylated in vitro by p34cdc2 protein kinase. The protein also binds to double-stranded DNA. These data suggest that xnf7 may function as a transcription factor. During oocyte maturation, xnf7 is released into the cytoplasm and is not detectable in nuclei until the mid-blastula-gastrula stage of development. Western blot analysis of xnf7 isolated from oocytes and eggs showed the existence of multiple bands or isoforms of the protein. Unique isoforms that are generated during oocyte maturation are the result of phosphorylation. The phosphorylated isoforms remain in the cytoplasm until the mid-blastula stage. The re-accumulation of protein in the embryonic nuclei at this time correlates with the increase in abundance of the less phosphorylated isoforms. The xnf7 protein possesses a nuclear localization signal (NLS) similar to the bipartite signal found in nucleoplasmin. Newly synthesized xnf7 accumulated in the oocyte GV to detectable levels within a few hours following synthesis suggesting that retention of the protein in the cytoplasm during early cleavage may be due to a process that interferes with the function of the NLS. These data suggest that compartmentalization and/or post-translational modification of the nuclear protein xnf7 may be involved in regulating its function during early development.

Animals↗
PubMed1991

Reliability of three clinical measures of muscle tone in the shoulders and wrists of poststroke patients.

Muscle tone was tested at the shoulders and wrists of 49 randomly selected poststroke patients with the use of resting joint position (SJP and WJP), resistance to passive movement or stiffness (SRM and WRM), and angle of appearance of resistance (SAR and WAR). Subjects were tested while seated with their arm supported in a suspension sling adapted for free movement. Five of the first and immediately repeated measurement pairs showed strong correlations and interrater reliability (SJP, .839; WJP, .900; SRM, .886; WRM, .904; SAR, .884 [p less than .05]). The sixth (WAR) showed moderate reliability (.618, p less than .05). Resting joint position measurements were most reliable among subjects with higher tone. The joint first measured had a slight order effect on SRM among subjects with higher muscle tone. Its second measurements were slightly increased over the first among those subjects whose shoulders were measured first and slightly reduced when measured immediately after the wrist. Reliable means of clinical evaluation of muscle tone at the shoulder and wrist are available if the influence of level of tone and the mutual influence of muscles tested are prudently considered.

Aged↗
PubMed1991

Carpal tunnel syndrome among ski manufacturing workers.

Carpal tunnel syndrome is a common disorder marked by pain and dysesthesias of the upper extremities. As a test of the hypothesis that carpal tunnel syndrome is associated with occupational risk factors, jobs at a ski assembly plant were classified as repetitive and nonrepetitive. The prevalence of carpal tunnel syndrome among 106 employees with repetitive jobs was compared with that among 67 employees with nonrepetitive jobs. The data collection included a questionnaire, a physical examination, and the measurement of distal sensory latencies of the median and ulnar nerves. Carpal tunnel syndrome was present in either or both hands in 15.4% of those workers with repetitive jobs, but only in 3.1% of those workers with nonrepetitive jobs (crude prevalence ratio 4.92, 95% confidence interval 1.17-20.7). The conclusion was drawn that carpal tunnel syndrome is associated with jobs requiring frequent and sustained hand work.

Adult↗