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Biomedical subjects

M Mills

Publications and source records attributed to M Mills.

At least 37 records · Page 2Linked to original sources
PubMed1999

Racial bias in federal nutrition policy, Part II: Weak guidelines take a disproportionate toll.

Many diet-related chronic diseases take a disproportionate toll among members of racial minorities. Research shows the prevalence of diabetes, hypertension, cancer, and heart disease is higher among various ethnic groups compared with whites. The Guidelines and the Food Guide Pyramid, however, promote the use of multiple servings of meats and dairy products each day and do not encourage replacing these foods with vegetables, legumes, fruits, and grains. The Dietary Guidelines for Americans encourage a 30% caloric reduction in fat intake and make no provision for further reductions for those who wish to minimize health risks. Abundant evidence has shown that regular exercise combined with diets lower in fat and richer in plant products than is encouraged by the Dietary Guidelines for Americans are associated with reduced risk of these chronic conditions. While ineffective Dietary Guidelines potentially put all Americans at unnecessary risk, this is particularly true for those groups hardest hit by chronic disease.

Cerebrovascular Disorders↗
PubMed1998

Funduscopic lesions associated with mortality in shaken baby syndrome.

PURPOSE: The shaken baby syndrome (SBS) has been defined as a syndrome of intraocular and intracranial hemorrhage in young children, thought to be caused by violent shaking inflicted by an adult. In many cases SBS is fatal as a result of intracranial injury. Intraocular findings include hemorrhage, which may be accompanied by characteristic retinal folds or retinoschisis lesions. This study was performed to determine whether acute ophthalmologic findings might predict a fatal outcome. METHODS: A consecutive series of 10 patients meeting a strict definition of SBS was reviewed for ophthalmic findings at presentation and outcome. RESULTS: Seven patients survived, and three died. Of the six funduscopic characteristics identified in these patients, two were significantly associated with a fatal outcome: circular perimacular retinal folds found in four patients (p = 0.048) and peripheral retinoschisis lesions seen in three patients (p = 0.012). Lack of visual response at initial examination was also significantly associated with a fatal outcome (p = 0.033). CONCLUSIONS: Ophthalmic examination of children with suspected SBS is important for prognostic as well as diagnostic purposes. Circular perimacular retinal folds, peripheral retinoschisis lesions, and lack of visual response correlated with fatal neurologic trauma and may be useful in predicting severity of central nervous system injury in shaken baby syndrome.

Battered Child Syndrome↗
PubMed1998

Structure of the Shigella dysenteriae haem transport locus and its phylogenetic distribution in enteric bacteria.

The ability to transport and use haemin as an iron source is frequently observed in clinical isolates of Shigella spp. and pathogenic Escherichia coli. We found that many of these haem-utilizing E. coli strains contain a gene that hybridizes at high stringency to the S. dysenteriae type 1 haem receptor gene, shuA. These shuA-positive strains belong to multiple phylogenetic groups and include clinical isolates from enteric, urinary tract and systemic infections. The distribution of shuA in these strains suggests horizontal transfer of the haem transport locus. Some haem-utilizing pathogenic E. coli strains did not hybridize with shuA, so at least one other haem transport system is present in this group. We also characterized the chromosomal region containing shuA in S. dysenteriae. The shuA gene is present in a discrete locus, designated the haem transport locus, containing eight open reading frames. Several of the proteins encoded in this locus participate with ShuA in haem transport, as a Salmonella typhimurium strain containing the entire haem transport locus used haem much more efficiently than the same strain containing only shuA. The haem transport locus is not present in E. coli K-12 strains, but the sequences flanking the haem transport locus in S. dysenteriae matched those at the 78.7 minute region of E. coli K-12. The junctions and flanking sequences in the shuA-positive pathogenic E. coli strains tested were nearly identical to those in S. dysenteriae, indicating that, in these strains, the haem transport locus has an organization similar to that in S. dysenteriae, and it is located in the same relative position on the chromosome.

Bacterial Outer Membrane Proteins↗
PubMed1998

Prospective care of elderly patients in family practice. Is screening effective?

OBJECTIVE: To evaluate cost and benefits of screening for and treating health and lifestyle risks among community-dwelling elderly. DESIGN: Randomized controlled trial. SETTING: Primary care. PARTICIPANTS: An opportunistic and prompted sample of 619 rostered elderly patients presenting for treatment who screened positive. INTERVENTIONS: One third (209) of experimental subjects had screening questionnaires placed in their charts with concerns highlighted for referrals. Two control groups received usual care. MAIN OUTCOME MEASURES: Yearly assessments of health service use and multidimensional functional capacity. RESULTS: Overall, screening and treatment of functionally active, elderly, middle-class people had no significant beneficial effect. Almost half of the experimental sample was ineligible because of treatment noncompliance. Generally ineligible subjects were older and more severely impaired. Subjects 75 years and older with risk factors showed improvement in daily living activities, and those living alone were found to have improved mental health and social functions (11% and 22%, respectively). CONCLUSIONS: Screening and treatment was ineffective in improving total functional capacity of all seniors 65 years and older. Elderly people 75 years and older, however, who were living alone or lonely did benefit from screening and treatment showing an improvement in daily activities, mental health scores, and social functions. This finding has implications for selective preventive health care spending for the elderly. A 2-year follow-up period could be too brief to detect long-term effects of early intervention with younger, middle-class seniors, especially those who are already functionally active.

Activities of Daily Living↗
PubMed1997

Identification of shuA, the gene encoding the heme receptor of Shigella dysenteriae, and analysis of invasion and intracellular multiplication of a shuA mutant.

shuA encodes a 70-kDa outer membrane heme receptor in Shigella dysenteriae. Analysis of the shuA DNA sequence indicates that this gene encodes a protein with homology to TonB-dependent receptors of gram-negative bacteria. Transport of heme by the ShuA protein requires TonB and its accessory proteins ExbB and ExbD. The shuA DNA sequence contains a putative Fur box overlapping the -10 region of a potential shuA promoter, and the expression of shuA is repressed by exogenous iron or hemin in a Fur-dependent manner, although hemin repressed expression to a lesser extent than iron salts. Disruption of this open reading frame on the S. dysenteriae chromosome by marker exchange yielded a strain that failed to use heme as an iron source, indicating that shuA is essential for heme transport in S. dysenteriae. However, shuA is not essential for invasion or multiplication within cultured Henle cells; the shuA mutant invaded and produced normal plaques in confluent cell monolayers.

Amino Acid Sequence↗
PubMed1996

Triple helical structures involving inosine: there is a penalty for promiscuity.

Inosine has the ability to act as a "wild-card" binding nonspecifically to both A.T and G.C base pairs. This has obvious implications for the design of oligonucleotide site-directed probes. In this paper we present a series of oligonucleotides with a 5'pur9-pyr9-pyr9 motif which are designed to fold up sequentially into intramolecular triple helices. One or more inosines are incorporated into the Hoogsteen strands in place of T's and/or C's. Once folded into the triplex, the inosine-containing third strand is incorporated in parallel orientation to the purine strand of the duplex. The influence of inosine on the triplex-duplex equilibrium, characterized by the melting temperature (Tm) and on the phase boundaries, as a function of pH and/or ionic strength, has been assessed by means of UV and CD spectroscopy. There are two distinguishable influences of third-strand inosines which affect binding, namely, backbone distortion due to bulkiness (I for T and I for C+) and/or loss of intramolecular ion pairs between protonated cytosines and the backbone phosphates (I for C+). A single thymine replacement drops the Tm by 25.0 (+/- 2.1) degrees C, and replacing a single protonated cytosine drops the Tm by 32.1 (+/- 1.0) degrees C at pH 6.0. On introducing two inosines in place of thymines, the Tm at pH 6.0 of the triple helix to hairpin transition is lowered by 35.5 (+/- 1.4) degrees C; on introducing two inosines in place of cytosines, the Tm drops by 44.5 (+/- 1.0) degree C, and on replacing a cytosine and a neighboring thymine with inosines, the Tm of the same transition is lowered by 29.2 (+/- 1.6) degrees C. Replacing more than two thymines or cytosines, respectively, eliminates the binding of the Hoogsteen strand at room temperature altogether. Under no circumstances does inosine replacement stabilize the triplex helix: it is a poor substitute and its role as a wild-card is limited.

Base Composition↗
PubMed1995

Genetics and regulation of heme iron transport in Shigella dysenteriae and detection of an analogous system in Escherichia coli O157:H7.

Shigella species can use heme as the sole source of iron. In this work, the heme utilization locus of Shigella dysenteriae was cloned and characterized. A cosmid bank of S. dysenteriae serotype 1 DNA was constructed in an Escherichia coli siderophore synthesis mutant incapable of heme transport. A recombinant clone, pSHU12, carrying the heme utilization system of S. dysenteriae was isolated by screening on iron-poor medium supplemented with hemin. Transposon insertional mutagenesis and subcloning identified the region of DNA in pSHU12 responsible for the phenotype of heme utilization. Minicell analysis indicated that a 70-kDa protein encoded by this region was sufficient to allow heme utilization in E. coli. Synthesis of this protein, designated Shu (Shigella heme uptake), was induced by iron limitation. The 70-kDa protein is located in the outer membrane and binds heme, suggesting it is the S. dysenteriae heme receptor. Heme iron uptake was found to be TonB dependent in E. coli. Transformation of an E. coli hemA mutant with the heme utilization subclone, pSHU262, showed that heme could serve as a source of porphyrin as well as iron, indicating that the entire heme molecule is transported into the bacterial cell. DNA sequences homologous to shu were detected in strains of S. dysenteriae serotype 1 and E. coli O157:H7.

Bacterial Proteins↗
PubMed1994

Care of dying patients in hospital.

OBJECTIVE: To study the process of care of dying patients in general hospitals. DESIGN: Non-participant observer (MM) carried out regular periods of continuous comprehensive observation in wards where there were dying patients, recording the quantity and quality of care given. Observations were made in 1983. SETTING: 13 wards (six surgical, six medical, and one specialist unit) in four large teaching hospitals (bed capacity 504-796) in west of Scotland. SUBJECTS: 50 dying patients (29 female, 21 male) with mean age of 66 (range 40-89); 29 were dying from cancer and 21 from non-malignant disease. RESULTS: Final period of hospitalisation ranged from 6 hours to 24 weeks. More than half of all patients retained consciousness until shortly before death. Basic interventions to maintain patients' comfort were often not provided: oral hygiene was often poor, thirst remained unquenched, and little assistance was given to encourage eating. Contact between nurses and the dying patients was minimal; distancing and isolation of patients by most medical and nursing staff were evident; this isolation increased as death approached. CONCLUSIONS: Care of many of the dying patients observed in these hospitals was poor. We need to identify and implement practical steps to facilitate high quality care of the dying. Much can be learned from the hospice movement, but such knowledge and skills must be replicated in all settings.

Adult↗
PubMed1993

Galanin: structure-dependent effect on pancreatic amylase secretion and jejunal strip contraction.

Rat and porcine galanin and their fragments inhibited cholecystokinin-8 (CCK-8)-stimulated amylase secretion with the following activities: rat galanin-(1-29) = porcine galanin-(1-29) = galanin-(1-15) = rat galanin-(3-29) > rat galanin-(2-29) = porcine galanin-(2-29) > galanin-(1-10). Fragments of rat galanin-(9-29) and N alpha-acetyl-galanin-(9-29) were able to inhibit CCK-8-stimulated pancreatic amylase secretion but only at higher dose levels. Porcine galanin-(15-29) and rat galanin-(21-29) were unable to produce significant inhibition. Rat and porcine galanin-(1-29), galanin-(1-15) and rat N alpha-acetyl-galanin-(9-29) also inhibited basal pancreatic amylase secretion. In the rat jejunal strip contraction model, rat galanin-(1-29) and porcine galanin-(1-29) have similar potencies. Galanin-(1-15) and galanin-(1-10) stimulate rat jejunal strip contraction with decreasing potencies. Elimination of Gly1 from the N-terminus of both rat and porcine galanin had no significant effect either on pancreatic amylase secretion or on jejunal strip contraction. The rat galanin-(3-29) and (9-29) are not active in the stimulation of rat jejunal strip contraction. Acetylation of porcine galanin-(9-29) created a peptide that was a powerful stimulator of rat jejunal strip contraction. The present data indicate that N-terminal rat galanin amino acid residues are crucial for rat jejunal strip contraction but are not required for inhibition of pancreatic amylase. These results suggest that the galanin amino acid sequence contains several specific domains, which can be recognized by specific galanin receptor subsets.

Amino Acid Sequence↗
PubMed1993

The peri-implant sulcus.

A review of the peri-implant sulcus, including the histology of the sulcular epithelium, epithelial attachment, and the gingival connective tissue, is presented. The peri-implant junctional epithelial attachment is mediated by hemidesmosomes, as in the periodontal tissue. There is some controversy on the possible attachment of connective tissue fibers to the implant, but current studies indicate a parallel orientation with no insertion of the peri-implant connective tissue fibers. This difference in connective tissue attachment may affect the peri-implant tissue's susceptibility to disease.

Animals↗
PubMed1992

Comparative effects of fenoldopam mesylate and nitroprusside on left ventricular performance in severe systemic hypertension.

To compare the effects of fenoldopam (n = 15), a selective dopamine-1 agonist, and nitroprusside (n = 14) on left ventricular (LV) function in severely hypertensive subjects (diastolic blood pressure (BP) greater than 120 mm Hg), both agents were infused to reduce diastolic BP by 40 mm Hg (or less than 110 mm Hg). Indexes of LV systolic and diastolic functions were obtained using gated radionuclide angiography before the initiation of treatment and after targeted BP was achieved. Both fenoldopam and nitroprusside effectively reduced systolic and diastolic BP to target levels. Changes in heart rate, peak filling rate and relative end-diastolic volume were similar with both agents. Baseline ejection fraction increased after infusion of both drugs. The magnitude of the increase in ejection fraction was far greater with fenoldopam than with nitroprusside (+22% vs +8%; p = 0.04), despite a lesser reduction in systolic BP (-12 vs -22%, p = 0.002). Furthermore, the reduction in relative end-systolic volume (-35 vs -20%; p = 0.04), and increase in the ratio of peak systolic pressure to relative end-systolic volume (+43 vs +6%; p = 0.007) were greater after fenoldopam than after nitroprusside. The greater increment in parameters of LV systolic function produced by fenoldopam than by nitroprusside suggests an effect on LV performance that is independent of afterload reduction.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1992

Percutaneous umbilical blood sampling: results from a multicenter collaborative registry. The Western Collaborative Perinatal Group.

Percutaneous umbilical blood sampling has become an important diagnostic tool in the evaluation of fetal health. Although recent reports have established the safety of this procedure, most have arisen from single centers with extensive experience. The Western Perinatal Collaborative Group has maintained a continuous registry of percutaneous umbilical blood sampling performed at the 13 member institutions for the years 1986 through 1990. During this period 302 procedures were performed. Primary indications for percutaneous umbilical blood sampling included Rh and non-Rh isoimmunization, intrauterine growth retardation, nonimmune hydrops, fetal anomalies, immune thrombocytopenia purpura, and rapid fetal chromosome analysis. Percutaneous umbilical blood sampling was successfully performed in 93.7% of cases with a sample withdrawn by a single puncture in 80.5% of attempts. In the majority of cases a 22-gauge needle was used. Postprocedural fetal death resulted in six cases (2.1%) and was most often associated with fetal anomalies or an abnormal karyotype. In conclusion, evaluation of the fetal state by percutaneous umbilical blood sampling is a safe and easily performed procedure, as demonstrated by a collaborative multicenter study.

Blood Specimen Collection↗
PubMed1992

Gender influences on age cognitions and preferences: sociocultural or sociobiological?

The present article reviews research concerned with gender effects on cognitions and evaluations of people varying in age. Sontag's (1979) article on the double standard of aging--the purportedly more negative consequences of aging in women in contrast to men--serves as a point of departure for the review. Research using attitude-scale, semantic differential, and person-perception methodology points to sex-of-target, sex-of-subject, and target-subject interaction effects in response to a diversity of age-relevant stimuli. Though the reported studies are not completely consistent, there is much suggestive evidence that age is a more salient dimension for men than for women when judging others. Furthermore, men exhibit a stronger youth bias. The overall evidence is consistent with an evolutionary hypothesis, but further research that focuses on the proximal determinants of the observed effects is urged.

Aged↗
PubMed1992

Plaque-induced inflammation around implants.

This article is a review of plaque-induced inflammation around dental implants. The microflora around successful implants is similar to healthy sulci, while that associated with failing implants is similar to periodontally diseased sites. Implant microflora is similar to the tooth microflora in the partially edentulous mouth. The microflora of implants in partially edentulous mouths differs from that in edentulous mouths. This seems to indicate a bacterial reservoir around the teeth and the possibility of reinfection of the implant sulcus by periodontal pathogens. The maintenance of a tooth microflora consistent with periodontal health in partially edentulous mouths may lead to maintaining an implant microflora consistent with peri-implant health. Thus, periodontal and implant maintenance are linked and neither can be overlooked.

Animals↗