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Biomedical subjects

D Quinn

Publications and source records attributed to D Quinn.

At least 37 records · Page 2Linked to original sources
PubMed1996

The changing radiographic presentation of bronchogenic carcinoma with reference to cell types.

OBJECTIVE: To analyze chest radiographic patterns of lung cancer at presentation by cell type. This current series is compared with historic published data. DESIGN: Retrospective, using a tumor registry. SETTING: Large, rural multispecialty clinic. PATIENTS: Three hundred forty-five patients with newly diagnosed lung cancers presenting between October 1990 and August 1992. METHODS: Radiographs were interpreted by two radiologists blinded to cell type. Our results were compared statistically to published data from Mayo Clinic patients in the 1950s and 1960s. RESULTS: (1) Adenocarcinoma: Decreased presentation as a peripheral tumor in current series (49%) compared with historic control at Mayo (72%); (2) squamous cell: increased presentation as peripheral tumor in current series (43%) compared with historic control (31%); and (3) no statistically significant difference between adenocarcinoma (49%) and squamous (43%) for a presentation as a peripheral mass, or between adenocarcinoma (46%) and squamous (52%) for central origin in the current series of cases. CONCLUSION: As adenocarcinoma has increased in relative frequency among lung cancers, the percent of cases with peripheral primary tumors is decreased while central tumors have increased. Squamous carcinoma has had a relative increase in peripheral mass presentation. There is now no significant difference between these two cell types in percent presenting as a peripheral mass or central tumor on chest radiograph.

Adenocarcinoma↗
PubMed1995

Gain and loss of hypersensitivity to resistance modifiers in multidrug resistant Chinese hamster ovary cells.

Some, but not all, multidrug resistant cell lines exhibit collateral hypersensitivity to resistance modifiers. We have examined the relationship between levels of P-glycoprotein expression and resistance modifier hypersensitivity in Chinese hamster ovary cell lines. We have defined a model system for the gain and loss of such sensitivity which indicates that its presence is not simply proportional to P-glycoprotein levels, but is acquired only above a certain level of P-glycoprotein expression. We also show that previously reported differences in such sensitivity between lines is not attributable to differences in genetic background of the cell lines used for selection of drug resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Placement outcomes of 206 severely maltreated children in the Boston Juvenile Court system: a 7.5-year follow-up study.

This study examines placement outcomes of 206 severely maltreated children 7.5 years after arraignment in Boston Juvenile Court (BJC) on Care and Protection Petitions. Sixty-seven percent (n = 138) of the sample had been permanently removed from their parents and 33% (n = 68) had their cases dismissed in the BJC. At time of this follow-up, 21% of the full sample (n = 44) were still in temporary custody awaiting permanent placement. In addition, 4% (n = 8) of children had "drifted" back to their abusive/neglectful parents despite prior permanent removal. The average time children in this sample spent in probate proceedings (awaiting permanent placement) had increased substantially to 2.1 years since the last overview study of this sample 4 years ago. The rate of court referral for incidences of reabuse (a C&P filing), or delinquency was significantly lower among children who had been permanently placed (p < .003). Rates of court-referral for reabuse charges were the same (16%) for children who were in temporary custody at the time of follow-up and children who had been dismissed back to the parent for whom the original C&P had been filed. Results are discussed in light of the urgent need to restructure time limits in juvenile court proceedings, integrate adequate tracking of child abuse and neglect cases through and across court and agency boundaries, and the use standardized assessments of abused and neglected children as a tool in the adjudication process.

Adolescent↗
PubMed1995

Cell mediated immunity in Antarctic wintering personnel; 1984-1992.

Cell-mediated immune responses were studied in 12 Antarctic and sub-Antarctic wintering groups at quarterly intervals over the period 1984-1992, using the cutaneous CMI Multitest. These populations are among the most isolated on earth. While the sub-Antarctic population at Macquarie Island had levels of responsiveness and hypoergy (9%) comparable to healthy populations in temperate zones, the Antarctic Continental group showed a level of hypoergy of 36%. There was no seasonal variation in the pattern of responses. It is concluded that the extreme and isolated environment and stress factors are responsible for the decreased immunological responsiveness but the mechanisms are presently unclear. On review, one factor appears to be perceived anxiety. The high rate of hypoergy in Antarctica, where medical care is limited, may have health implications. These groups provide an excellent analogue for immunological investigations in longer term space flight.

Adult↗
PubMed1995

Immune responses during an Antarctic summer.

The immune status of 29 members of the Australian National Antarctic Research Expeditions (ANARE) was investigated before, during, and after a 56 day summer voyage to Antarctica and correlated with psychological and physiological parameters. All subjects were healthy. Expedition personnel demonstrated decreased cell mediated immune responses (CMI) assessed by the CMI Multi-test; 21% were hypoergic. The major associated observation was a significant negative correlation with anxiety in Antarctica. However, perceived anxiety was greater before and after the voyage. No significant changes were found in T and B lymphocyte subsets, immunoglobulin and complement components and cutaneous blood flow, nor was there any clinical evidence of illness. Of the hormones examined only cortisol was low predeparture which may reflect increased perceived anxiety at that time. Changes in immune control mechanism were apparent as shown by reduced CMI responses and lowered tetanus antibody levels. Stress factors are postulated to induce depression of the immune response in Antarctica. The association with anxiety suggests that brain peptides or associated cytokines may have a role in mediating these immune events. Such alterations in immune status have implications for health management in isolated and extreme conditions.

Adult↗
PubMed1995

Ambulatory medical detoxification for alcohol.

In the past decade, ambulatory medical detoxification for alcohol withdrawal has become increasingly utilized due to pressures to contain cost of treatment and research demonstrating its effectiveness. The research that describes this area spans the last 15 years. This article reviews the available literature on ambulatory detoxification and attempts to summarize and synthesize what is known about this area in order to make ambulatory medical detoxification readily reproducible in clinical practice. Finally, this article concludes with an analysis of the advantages and disadvantages of outpatient alcohol detoxification as compared to inpatient treatment.

Ambulatory Care↗
PubMed1995

Additives containing bacteria and enzymes for alfalfa silage.

First-cutting alfalfa was wilted, harvested from alternate rows, left untreated or treated with additives containing lactic acid bacteria and enzymes (cellulase, amylase, and pectinase), and ensiled in bag silos. Inoculation increased lactic acid bacteria from 5 x 10(4) to 1 x 10(6) cfu/g of forage. Because treatments were bagged consecutively, the DM of treated silages was higher than that of untreated silage. However, after 4 d of ensiling, the pH of treated silage, about 4.3, was lower than that of untreated silage, 4.7, and remained lower throughout the ensiling period. After 177 d of ensiling, total lactate was about 25% higher, and ammonia N was about 40% lower, in treated silage. In addition, NDF and ADF contents were lower in treated than in untreated silage. Between 51 and 177 d of storage, glucose content increased in treated silage, but not in untreated silage, suggesting that some plant cell-wall hydrolysis occurred during prolonged storage. In vitro digestion of NDF did not differ among treatments during early incubation, but the extent of digestion after 36 and 48 h was lower in treated than in untreated silage. The microbial and enzyme silage additives used in this study improved fermentation characteristics and reduced fiber content of silage but decreased the in vitro digestibility of fiber.

Amylases↗
PubMed1994

Identification of amino acid residues involved in the binding of Huperzine A to cholinesterases.

Huperzine A, a potential agent for therapy in Alzheimer's disease and for prophylaxis of organophosphate toxicity, has recently been characterized as a reversible inhibitor of cholinesterases. To examine the specificity of this novel compound in more detail, we have examined the interaction of the 2 stereoisomers of Huperzine A with cholinesterases and site-specific mutants that detail the involvement of specific amino acid residues. Inhibition of fetal bovine serum acetylcholinesterase by (-)-Huperzine A was 35-fold more potent than (+)-Huperzine A, with KI values of 6.2 nM and 210 nM, respectively. In addition, (-)-Huperzine A was 88-fold more potent in inhibiting Torpedo acetylcholinesterase than (+)-Huperzine A, with KI values of 0.25 microM and 22 microM, respectively. Far larger KI values that did not differ between the 2 stereoisomers were observed with horse and human serum butyrylcholinesterases. Mammalian acetylcholinesterase, Torpedo acetylcholinesterase, and mammalian butyrylcholinesterase can be distinguished by the amino acid Tyr, Phe, or Ala in the 330 position, respectively. Studies with mouse acetylcholinesterase mutants, Tyr 337 (330) Phe and Tyr 337 (330) Ala yielded a difference in reactivity that closely mimicked the native enzymes. In contrast, mutation of the conserved Glu 199 residue to Gln in Torpedo acetylcholinesterase produced only a 3-fold increase in KI value for the binding of Huperzine A.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholinesterase↗
PubMed1993

Radionuclide hepatobiliary scanning in patients with AIDS-related sclerosing cholangitis.

Biliary disease, primarily manifesting as papillary stenosis or sclerosing cholangitis, is being increasingly recognized as a problem in the acquired immunodeficiency syndrome (AIDS) and may be amenable to specific treatment. Ultrasound, followed by endoscopic retrograde cholangiopancreatography (ERCP) for definitive diagnosis, is currently the prime mode of investigation of suspected hepatobiliary diseases in AIDS. There are few published reports of the use of radionuclide cholescintigraphy in the assessment of these patients. This report presents Tc-99m DISIDA cholescintigraphy data from three patients with AIDS-related hepatobiliary disease confirmed by ERCP. Radionuclide cholescintigraphy was abnormal in all three patients. In two of the subjects, there was focal duct dilation with strictures in the biliary tree. The third patient demonstrated diffuse hepatic parenchymal retention with marked delay in tracer washout. Two of the subjects, treated with specific anticryptosporidial therapy, subsequently underwent progress cholescintigraphy. In one of these patients with initial diffuse parenchymal retention, there was marked improvement in scan appearances. The second patient with initial duct dilation had no significant change in scan appearances, but quantitative analysis did demonstrate improvement in hepatobiliary tracer clearance rate. In conclusion, although ERCP remains the gold standard in the diagnosis of AIDS-related biliary disease, radionuclide cholescintigraphy may be a useful modality in these patients as a screening test before proceeding to more expensive and invasive techniques. In addition, quantitative analysis of cholescintigraphy may allow assessment of patient response to specific antimicrobial or surgical intervention.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Serious child mistreatment in Massachusetts: the course of 206 children through the courts.

Two hundred and six severely abused and/or neglected children brought before the Boston Juvenile Court on care and protection petitions were followed prospectively for 4 years. Two thirds of all parents were found to be poor, 84% had one or more psychiatric disorders, and 81% had been known to the Department of Social Services prior to their court appearance. The average age of children at the start of the court process was 4.2 years, and the average length of temporary foster care was 2.3 years. Judges' decisions to return children to parental custody or to order permanent removal were most strongly predicted by parental compliance with court-order services. Of the 63 cases dismissed from court and thus returned to biological parents, 18 (29%) had substantiated reports of new mistreatment over an approximately 3-year follow-up period. We concluded that children are often poorly served by the current delays in the social service/legal system, and that further clinical research would provide needed empirical data on how best to protect mistreated children.

Adoption↗
PubMed1992

Enantioselective pharmacokinetics and pharmacodynamics of dl-threo-methylphenidate in children with attention deficit hyperactivity disorder.

Nine boys with attention-deficit hyperactivity disorder took part in a study in which d-methylphenidate, l-methylphenidate, dl-methylphenidate, or placebo were administered in a double-blind, four-way, randomized, crossover design. Plasma levels of the isomers of methylphenidate were monitored by means of an enantioselective assay method. The ability of the children to perform tasks that required sustained attention was monitored by a battery of computer tests. There was no evidence of interconversion between the enantiomers in vivo, although the presence of the d-isomer significantly altered the pharmacokinetics of the l-antipode. The presence of the l-isomer did not affect the pharmacokinetics of d-methylphenidate. The computer tests revealed a drug-induced improvement in sustained attention that was entirely attributable to the d-enantiomer. There was no evidence to suggest that the effectiveness of d-methylphenidate was in any way compromised by the presence of its antipode.

Analysis of Variance↗