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Biomedical subjects

C Miller

Publications and source records attributed to C Miller.

At least 55 records · Page 3Linked to original sources
PubMed2001

Reliability of CXR for the diagnosis of bronchopulmonary dysplasia.

BACKGROUND: Bronchopulmonary dysplasia (BPD) continues to be prevalent, despite new treatment, in part because of increased survival in less mature infants. Investigations of new treatments have been hampered by a lack of universally accepted diagnostic criteria. Radiographic scoring systems have been developed to provide objective assessment of lung injury and risk for chronic lung disease. OBJECTIVE: We sought to test the reliability of a recently reported system using chest radiography as the main tool for diagnosis of BPD. MATERIALS AND METHODS: One hundred chest radiographs, half demonstrating BPD and the other half without BPD, were analyzed by pediatric radiologists and by a neonatologist, using the Weinstein score (1-6, depending on increasing radiographic severity). The reliability of this scoring system was tested by kappa (k) statistics. RESULTS: Reliability at the lowest threshold (dividing score 1 from score > or = 2) was unacceptably low in this population. Reliability increased with inclusion of higher BPD scores in the comparison groups: 1-3 versus 4-6. CONCLUSION: Using the chest radiograph for the prediction of BPD is not reliable between different observers except at the two extremes of the disease.

Bronchopulmonary Dysplasia↗
PubMed2001

Revisiting the role of Ca2+ in Shaker K+ channel gating.

Shaker K+ channels were expressed in outside-out macropatches excised from Xenopus oocytes, and the effects on gating of removal of extracellular Ca2+ were examined in the complete absence of intracellular divalent cations. Removal of extracellular Ca2+ by perfusion with EDTA-containing solution caused a small negative shift in the channel's voltage-activation curve and led to an increased nonselective leak, but did not otherwise alter or disrupt the channels. The results contradict the proposal that Ca2+ is an essential component required for maintenance of ion selectivity and proper gating of Kv-type K+ channels. The large nonselective leak in Ca2+-free conditions was found to be a patch-seal phenomenon related to F- ion in the recording pipette.

Animals↗
PubMed2001

von Willebrand disease and other inherited bleeding disorders in women with diagnosed menorrhagia.

OBJECTIVE: To estimate the prevalence of von Willebrand disease and other bleeding disorders in women with and without diagnosed menorrhagia. METHODS: Women with menorrhagia were identified among members of a health maintenance organization in the southeastern United States through a computer search for appropriate International Classification of Diseases, 9th Revision codes. A random sample of members with no such code was selected as controls. The study included 121 women with menorrhagia and 123 controls. Subjects were interviewed in person, and blood was drawn for coagulation testing. Laboratory results for menorrhagia patients were compared with those in controls using race and blood type specific ranges developed from the control group. A test was considered abnormal if it exceeded two standard deviations below the control mean. RESULTS: Bleeding disorders (von Willebrand disease, factor deficiency, or a platelet abnormality) were diagnosed in 10.7% of menorrhagia patients and 3.2% of controls (P =.02). von Willebrand disease was present in eight menorrhagia patients (6.6%) and in one control (0.8%) (P =.02); separate analyses by race revealed a von Willebrand disease prevalence of 15.9% among white and 1.4% among black menorrhagia patients (P =.01). Women with bleeding disorders did not differ significantly from controls in other symptoms of bleeding. CONCLUSION: The prevalence of inherited bleeding disorders among white women with menorrhagia was substantial, consistent with European data published recently. For unknown reasons, the prevalence of von Willebrand disease was lower among black women. These findings indicate the importance of considering inherited bleeding disorders as a cause of menorrhagia.

Adolescent↗
PubMed2001

Oriented Schwann cell growth on micropatterned biodegradable polymer substrates.

This paper investigates the influence of substrate-mediated chemical and physical guidance on the growth and alignment of Schwann cells in vitro. Novel techniques were developed to fabricate microgrooves with adsorbed proteins on biodegradable polymer substrates made of poly(D,L-lactic acid). Compression molding and solvent-casting were used to transfer micropatterns from quartz and silicon substrates onto biodegradable polymer films. Laminin was selectively adsorbed onto the grooves and rat sciatic Schwann cells were seeded on the substrates. Laminin was found to improve adhesion of Schwann cells on the substrates. The microgrooves were found to cause the Schwann cells to align along the direction of the grooves. The groove width influenced Schwann cell alignment the most, while groove depth did not seem to play a significant role. The degradation of the grooves in the solvent cast films was much slower than those in the compression-molded films, making them the preferred substrates for Schwann cell culture.

Biocompatible Materials↗
PubMed2001

Childhood animal cruelty and interpersonal violence.

Conduct disorder (CD) affects 2-9% of children in this country and has been found to be relatively stable through childhood, adolescence, and into adulthood. Although many behaviors that comprise CD have been studied, there has been a lack of research on cruelty to animals. It has been suggested that animal cruelty may be exhibited by 25% of CD children and that animal abuse may be the earliest symptom evident in CD children. In addition, several studies have found a significant relationship between childhood cruelty to animals and violence toward people. Available research is reviewed in this report, including early studies on the relationship between animal cruelty and interpersonal violence, recent assessment attempts, and intervention techniques. Future research needs are also outlined and discussed.

Adolescent↗
PubMed2001

National practice patterns of sentinel lymph node dissection for breast carcinoma.

BACKGROUND: The sentinel node is the first regional lymph node to receive tumor cells that metastasize through the lymphatic channel from a primary tumor. The tumor status of the sentinel node should reflect the tumor status of the entire regional node basin. Sentinel lymph node dissection (SLND) has recently been investigated for use in patients with early breast carcinoma to avoid the sequelae of complete axillary lymph node dissection (ALND). Published studies of SLND in breast cancer patients identify marked variations in technique, and there are few guidelines for credentialing surgeons to perform SLND. STUDY DESIGN: The purpose of this study was to assess the current practice of SLND for breast cancer in the United States. A 27-item questionnaire was mailed to 1,000 randomly selected Fellows of the American College of Surgeons. Responses were anonymous. Statistical analysis was performed using SAS software (SAS Institute, Cary, NC). RESULTS: Response rate was 41% (n = 410), and 77% of those who responded performed SLND for breast cancer. The majority (60%) of surgeons responding routinely ordered preoperative lymphoscintigraphy. Of those who did lymphoscintigraphy, 28% removed internal mammary lymph nodes when lymphoscintigraphy showed drainage to these nodes. Ninety percent of surgeons used both blue dye and radiocolloid. Eighty percent of centers responding performed routine immunohistochemistry on sentinel lymph nodes, and 15% performed reverse transcription polymerase chain reaction. Ninety-six percent of surgeons performed SLND for primary tumors 5 cm or smaller, and 95% performed SLND for an excisional cavity 6 cm and smaller. Twenty-eight percent performed SLND for high-grade ductal carcinoma in situ, and 28% of respondents performed 10 or fewer SLND procedures with subsequent ALND before performing SLND alone. Surgeons learned SLND through courses (35%), oncology fellowships (26%), observation of other surgeons (31%), or were self-taught (26%). CONCLUSIONS: The majority of surgeons in the United States use similar technique for SLND breast cancer. But, there was marked variation in the number of SLND cases validated by an ALND before performing SLND only.

Academic Medical Centers↗
PubMed2001

Food shopping practices are associated with dietary quality in low-income households.

ABSTRACT Nutrition education for low-income audiences often focuses on building skills in food shopping and food resource management to help families receive the best nutrition from the resources they have available. However, empirical evidence for the effect of food shopping practice on dietary quality has been limited. This article presents new analyses from two studies that found an association between food shopping practices and diet quality. Logistic regression of data from 957 respondents from the 1996 National Food Stamp Program Survey found that food shopping practices were significantly (p </= .05) associated with the availability of nutrients in the food the households used during a week. Similarly, analysis of baseline data from 5159 women from selected counties of states who participated in the Expanded Food and Nutrition Education Program found that food shopping practices were significantly (p </= .05) associated with increased consumption of nutrients as measured through a single 24-hour recall. These findings suggest that food shopping practices are an important area for nutrition education with low-income audiences.

Diet↗
PubMed2001

The RepA protein of plasmid pSC101 controls Escherichia coli cell division through the SOS response.

Although plasmid copy number varies widely among different plasmid species, normally copy number is maintained within a narrow range for any given plasmid. Such copy number control has been shown to occur by regulation of the rate of plasmid DNA replication. Here we report a novel mechanism by which the pSC101 plasmid also can detect an imbalance between the cellular level of its replication protein, RepA, and plasmid-borne RepA binding sites to inhibit bacterial DNA replication and delay host cell division when RepA is in relative excess. We show that delayed cell division occurs by RepA-mediated induction of the SOS response and can be reversed by over-expression of the host DNA primase, DnaG. The effects of RepA excess are prevented by introducing a surfeit of RepA binding sites. The mechanism reported here may help to limit variation in plasmid copy number and allow repopulation of cells with plasmids when copy number falls--potentially pre-empting plasmid loss in cultures of dividing cells.

Binding Sites↗
PubMed2001

One-pass CO2 versus multiple-pass Er:YAG laser resurfacing in the treatment of rhytides: a comparison side-by-side study of pulsed CO2 and Er:YAG lasers.

BACKGROUND: The CO2 laser is normally described as an aggressive resurfacing tool, whereas the erbium:YAG laser has enjoyed a reputation as the ideal tool for superficial resurfacing. The implication from many studies is that the CO2 laser is incapable of "minimally invasive" resurfacing. OBJECTIVE: To compare a short-pulsed CO2 laser with an Er:YAG laser over a range of parameters intended to produce equivalent microscopic and clinical injuries. METHODS: A prospective, randomized, comparative interventional trial was conducted in a tertiary care teaching hospital. Thirteen patients with facial wrinkles were enrolled in the study. A side-by-side comparison was performed using periorbital and perioral regions as treatment sites. One side was treated with a pulsed CO2 laser and the other with an Er:YAG laser. Postauricular skin was treated in an identical fashion to the study sites and biopsied for microscopic analysis. The biopsies were obtained before treatment, immediately after treatment, and either 3 or 6 months after treatment to evaluate the acute level of injury and subsequent degree of fibroplasia. Photographs were taken at baseline, immediately after treatment, 1, 2, and 6 weeks, and 3 and 6 months after treatment. Nine physicians evaluated the photographs for erythema, pigmentation, and wrinkle improvement. RESULTS: Investigator assessment showed no statistically significant differences between the lasers with respect to hyperpigmentation and wrinkle reduction. There was less erythema at the CO2 laser-treated sites 2 weeks after treatment; the differences had resolved by 6 weeks after treatment. Histologic examination demonstrated equivalent dermal thermal injury on immediate postoperative biopsies and equivalent fibroplasia on subsequent biopsies. Both CO2 and Er:YAG laser-treated sites showed overall modest wrinkle improvement compared to the pretreatment photographs. CONCLUSION: When CO2 and Er:YAG lasers are used in a manner such that there are equivalent immediate postoperative histologic results, equivalent healing and cosmetic improvement occurs. One can use CO2 laser with one pass to mimic a moderately aggressive Er:YAG laser treatment.

Adult↗
PubMed2001

Risk profile of SSrIs in elderly depressive patients with co-morbid physical illness.

BACKGROUND: So far, most studies on treatment strategies in elderly depressive patients have included only patients in good physical health, thereby excluding and neglecting somatic co-morbidity, which is very prevalent and relevant in geriatric psychiatry. METHOD: 40 elderly depressive inpatients at the Department of Internal Medicine in Hochzirl who had started on SSRI monotherapy were allocated to this prospective post-marketing surveillance study. A stable medication for their physical illness for at least six months was a prerequisite. A Mini Mental State Exam (MMSE) score of >24 was required for study entry. The four-week study consisted of one baseline and four follow-up examinations, including psychiatric and medical history, as well as ratings for psychopathology and treatment-related adverse events. The antidepressants administered were paroxetine (20 mg/d), citalopram (20 mg/d), fluoxetine (20 mg/d) and sertraline (50 mg/d). Depression was rated using the 21-item Hamilton Depression Scale (HAMD); side effects were evaluated by the UKU Side Effect Rating Scale, and we used the Hillside Akathisia Scale (HAS) to record the incidence of SSRI-induced akathisia. RESULTS AND CONCLUSION: Our results suggest that SSRls are effective and reasonably safe in elderly depressive patients with co-morbid physical illness. Adverse effects are more common, but generally tolerable, than in younger and physically healthy patients. The risk profile of SSRls in this population can be considered favorable.

Aged↗
PubMed2001

Interferon beta-1a in children with multiple sclerosis is well tolerated.

BACKGROUND: Multiple sclerosis is a chronic demyelinating disease rare in children. Currently marketed disease modifying therapies are limited to adults. OBJECTIVE: To determine the tolerability of interferon beta-1a (IFNB-1 a) 30 mcg injected intramuscularly once a week in children with clinically definite relapsing-remitting multiple sclerosis (RRMS). DESIGN/METHODS: A standardized questionnaire was sent to neurologists in the United States to determine the tolerability of IFNB-1 a in patients younger than 16 years. RESULTS: Tolerability data were available for 9 of 33 children who were reported to initiate IFNB-1 a. Mean age on initiating treatment was 12.7 years (range 8 - 15) and mean duration of therapy was 17 months (range 5 - 36). No patient discontinued therapy due to an adverse event. CONCLUSIONS: Preliminary data indicate that weekly intramuscular injections of IFNB-1 a are well tolerated.

Adjuvants, Immunologic↗
PubMed2001

Effects of external loading on power output in a squat jump on a force platform: a comparison between strength and power athletes and sedentary individuals.

The aim of this study was to determine the effects of external loading on power output during a squat jump on a force platform in athletes specializing in strength and power events (6 elite weight-lifters and 16 volleyball players) and in 20 sedentary individuals. Instantaneous power was computed from time-force curves during vertical jumps with and without an external load (0, 5 or 10 kg worn in a special vest). The jumps were performed from a squat position, without lower limb counter-movement or an arm swing. Peak instantaneous power corresponded to the highest value of instantaneous power during jumping. Average power throughout the push phase of the jump was also calculated. A two-way analysis of variance showed significant interactions between the load and group effects for peak instantaneous power (P< 0.01) and average power (P< 0.001). Peak instantaneous power decreased significantly in sedentary individuals when moderate external loads were added. The peak instantaneous power at 0 kg was greater than that at 5 and 10 kg in the sedentary individuals. In contrast, peak instantaneous power was independent of load in the strength and power athletes. Mean power at 0 kg was significantly lower than at 5 kg in the athletes; at 0 kg it was significantly higher than at 10 kg in the sedentary males and at 5 and 10 kg in the sedentary females. In all groups, the force corresponding to peak instantaneous power increased and the velocity corresponding to peak instantaneous power decreased with external loading. The present results suggest that the effects of external loading on peak instantaneous power are not significant in strength and power athletes provided that the loads do not prevent peak velocity from being higher than the velocity that is optimal for maximal power output.

Adult↗
PubMed2001

KcsA: it's a potassium channel.

Ion conduction and selectivity properties of KcsA, a bacterial ion channel of known structure, were studied in a planar lipid bilayer system at the single-channel level. Selectivity sequences for permeant ions were determined by symmetrical solution conductance (K(+) > Rb(+), NH(4)(+), Tl(+) >> Cs(+), Na(+), Li(+)) and by reversal potentials under bi-ionic or mixed-ion conditions (Tl(+) > K(+) > Rb(+) > NH(4)(+) >> Na(+), Li(+)). Determination of reversal potentials with submillivolt accuracy shows that K(+) is over 150-fold more permeant than Na(+). Variation of conductance with concentration under symmetrical salt conditions is complex, with at least two ion-binding processes revealing themselves: a high affinity process below 20 mM and a low affinity process over the range 100-1,000 mM. These properties are analogous to those seen in many eukaryotic K(+) channels, and they establish KcsA as a faithful structural model for ion permeation in eukaryotic K(+) channels.

Algorithms↗
PubMed2001

Micropatterned Schwann cell-seeded biodegradable polymer substrates significantly enhance neurite alignment and outgrowth.

Biomimetic strategies were employed to promote directional outgrowth of neurites in vitro by using a synergistic combination of physical, chemical, and cellular cues. Compression molded and solvent cast biodegradable polymer substrates made of poly(D,L-lactic acid) were micropatterned to form grooves on the substrate surfaces. Laminin was localized in the grooves, and rat sciatic Schwann cells were seeded on the substrates. Whole as well as dissociated rat dorsal root ganglia were seeded on the substrates along with Schwann cells, and neurite outgrowth and alignment were measured. The micropatterns provide physical guidance, laminin provides chemical cues, and the Schwann cells provide biological cues to the axons. The presence of Schwann cells in the grooves was found to promote neurite alignment as well as outgrowth and help the neurites orient even on shallower grooves and exhibit continued alignment even as the grooves degrade. The synergistic combination of physical, chemical, and cellular guidance enabled greater than 98% alignment of neurites and accelerated outgrowth of neurites in the direction of the microgrooves.

Animals↗
PubMed2001

A phenomenologic assessment of relapsing MS patients' experiences during treatment with interferon beta-1a.

The purpose of this study was to describe the experiences of patients with relapsing multiple sclerosis (MS) who are being treated with interferon beta-1a. MS patients often experience fear and uncertainty about their future and derive benefit from understanding their diagnosis as well as learning about their anticipated disease course. Interferon beta-1a treatment can delay the accumulation of physical disability that naturally occurs over time in patients with untreated relapsing MS and thus offer hope for their future. However, patients may be afraid to start interferon beta-1a because they do not know what to expect. To answer the question, "What is the patient's experience on interferon beta-1a," we used Heideggerian phenomenologic and Colaizzi's qualitative data analysis techniques to interpret serial interviews of 15 patients with relapsing MS. Interviews were audiotaped, transcribed verbatim, and analyzed by using the Martin qualitative data analysis computer program. The theme clusters that emerged were learning, feelings, adaptation, and interferon beta-1a issues. An exhaustive description of the phenomena that were derived illustrates the patients' process of learning about their illness and adapting to changes in their lives. Starting a new treatment requires coping and challenges use of resources. Social support is vital to patients, particularly those who have difficulty injecting themselves. Most of the patients expressed a sense of improvement in their condition since starting on interferon beta-1a treatment and considered it crucial to their hope for the future.

Adaptation, Psychological↗