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K Lewis

Publications and source records attributed to K Lewis.

At least 73 records · Page 4Linked to original sources
PubMed1998

Expanded profile of the SHAFT syndrome.

The SHAFT syndrome is a factitious disorder in which a patient manipulates the surgeon to perform operations to fulfill his or her psychological needs. The acronym describes patients who are sad, hostile, anxious, frustrating, and tenacious. A chart review from January 1990 to June 1996 was undertaken to provide a profile to aid in the recognition and diagnosis of the SHAFT syndrome. An analysis of 28 patients revealed characteristics supporting a definitive SHAFT profile. Patients with SHAFT syndrome seek physicians to perform invasive procedures. Their typical complaint is pain, usually without objective physical findings that would support a more definitive diagnosis. Such patients tend to be women, cry with pain, describe symptoms out of proportion to objective findings, and have a history of psychiatric care.

Adult↗
PubMed1998

Phosphonate and bisphosphonate analogues of farnesyl pyrophosphate as potential inhibitors of farnesyl protein transferase.

Several phosphonate and bisphosphonate analogues of farnesyl pyrophosphate have been prepared for an examination of their ability to inhibit farnesyl protein transferase (FPTase). A Horner-Wadsworth-Emmons condensation of farnesal or geranial with tetraethyl methylenediphosphonate gave the desired vinyl phosphonates, while alkylation of the dimethyl methylphosphonate anion with a terpenoid bromide gave the corresponding saturated phosphonates. Alkylation of tetraethyl methylenediphosphonate with farnesyl bromide gave the expected alkyl bisphosphonate, which was converted to its alpha, beta-unsaturated derivative by preparation of the phenyl selenide, oxidation to the selenoxide, and elimination. In a similar fashion, triethyl phosphonoacetate was converted to a farnesyl pyrophosphate analogue by reaction with farnesyl bromide. After preparation of the respective acids, each compound was tested for inhibition of FPTase at concentrations ranging up to 10 microM. The effect of these compounds on FPTase activity varied substantially, ranging from depressed to surprisingly enhanced enzymatic activity.

Alkyl and Aryl Transferases↗
PubMed1998

L-NAME potentiates endothelin-stimulated thromboxane release from guinea pig lung.

The bronchoconstrictor response after systemic administration of endothelins (ETs) in the guinea pig is indirectly mediated by thromboxane A2 (TxA2) release through ETB receptor activation. ETs also trigger the release of nitric oxide (NO) in endothelial cells by activation of ETB receptors. A growing body of evidence indicates that endogenous NO plays a key role in the regulation of pulmonary function. In this study we investigated the effect of an NO synthase inhibitor, L-NAME, on the release of TxA2 from the isolated, perfused guinea pig lung induced either by ET-1, the selective ETB receptor agonist IRL-1620, bradykinin (BK), or a TxA2-mimetic, U 46619. A 30 min intra-arterial (intra-arterial) infusion of L-NAME (300 microM) potentiated the TxA2 release with ET-1, IRL 1620, and BK (5, 50, and 50 nM, respectively) infused for 3 min (i.a.). U 46619 (10 nM) was ineffective as a stimulant of pulmonary eicosanoid release. Interestingly, L-NAME did not potentiate the release of prostacyclin (PGI2) triggered by ET-1, IRL 1620, or BK. Our results suggest a predominant role of ETB receptor activation in the release of TxA2. Furthermore, we suggest that NO in the guinea pig lung is a potent modulator of the TxA2 releasing activity of ET-1, IRL 1620, and BK, three agonists known to stimulate the release of NO.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1998

Audit of timing of antibiotic prophylaxis in hip and knee arthroplasty.

Infection following arthroplasty can have devastating consequences. Antibiotic prophylaxis is routinely given in modern orthopaedic practice in an attempt to reduce infection rates. The aim is to achieve clinically useful tissue concentrations of antibiotic peri-operatively, and this is accomplished with antibiotic administration at induction of anaesthesia and at 6 and 12 h post-operatively. The case notes of 16 consecutive patients undergoing elective joint replacement surgery were reviewed. All received antibiotic prophylaxis, but the time intervals between doses were longer than the current standard in 50% of patients for the second dose and 81% of patients for the third dose. Our practice has been reviewed to ensure that all patients receive antibiotics at the appropriate times.

Antibiotic Prophylaxis↗
PubMed1997

Arylsulphatase A pseudodeficiency in vascular dementia and Alzheimer's disease.

The carrier rates of a genetic marker for arylsulphatase A pseudodeficiency (ASA-PD) were determined in three series of patients with vascular dementia (VaD) or Alzheimer's disease (AD). In the first community-based sample, the 1524 + 95A-->G mutation, which is known to be associated with ASA-PD, was present in 35% of VaD cases and none of the AD cases. In a second sample of cases drawn from a Dementia Register, the mutation rates were 18% (VaD) and 16% (AD). Brain DNA from a post-mortem sample revealed the ASA-PD mutation in 60% of VaD cases and 34% of AD cases. These rates are higher than previous studies of culturally similar populations and suggest that ASA-PD may be a risk factor for dementia.

Adenine↗
PubMed1997

Fabatins: new antimicrobial plant peptides.

Two new antimicrobial peptides related to the gamma-thionine family have been isolated by acid extraction from the broad bean Vicia faba. The extract was separated by ion exchange chromatography, and a fraction showing antibacterial activity was further purified by reverse-phase HPLC. Material from a single HPLC peak was sequenced and revealed the presence of two peptides differing by one amino acid. The peptides were named fabatins. They are 47 amino acids long, have an overall positive charge and contain 8 cysteines that probably form 4 disulfide bridges characteristic of the gamma-thionins. Fabatins were active against both Gram-negative and Gram-positive bacteria, but were inactive against the yeasts Saccharomyces cerevisiae and Candida albicans.

Anti-Bacterial Agents↗
PubMed1997

A functional analysis of Notch mutations in Drosophila.

The Notch gene encodes a receptor protein that is involved in many processes during development. Its best understood role is during neurogenesis in a process called "lateral inhibition." However, it has been proposed that Notch also has a role in defining the proneural clusters in the first place. This raises the possibility that the Notch protein is acting as a multifunctional receptor. To test this hypothesis, we have carried out a genetic analysis of molecularly characterized Notch alleles to identify alleles that affect only one of the two proposed functions. Here we present evidence that Notch alleles can be identified that appear to affect the function of Notch during either lateral inhibition or the definition of proneural clusters. In addition our results indicate that there may be discrete regions of the Notch protein required for each function.

Alleles↗
PubMed1997

Orofacial manifestations and seroprevalence of HIV infection in Namibian dental patients.

SUBJECTS AND METHODS: In an anonymous study of HIV-I sero-reactivity in dental patients in a Government clinic in Namibia, 29 (7%) out of 405 patients (10 female and 19 male) were confirmed as HIV-infected. HIV-antibody testing was done cheaply and conveniently by collecting and storing finger-prick blood on absorbent paper, and eluting the samples 7 weeks later. Testing was done by GACPAT, a simple, inexpensive temperature independent assay which requires no specialised equipment. RESULTS AND CONCLUSIONS: Six patients had orofacial lesions, including Kaposi's sarcoma, leukoplakia (bilateral on buccal mucosa), cervical lymphadenopathy, hairy leukoplakia, circum-oral herpes simplex, HIV-gingivitis and necrotising ulcerative gingivitis. This sampling and testing system is well suited for use in epidemiological surveys in developing countries.

AIDS Serodiagnosis↗
PubMed1997

Is religion relevant?

Explore the source record for details and available documents.

Centers for Medicare and Medicaid Services, U.S.↗
PubMed1997

Effect of neuropeptide Y on bradykinin-induced release of prostacyclin and thromboxane from guinea pig perfused lung.

We have previously reported that neuropeptide Y (NPY) inhibits responses induced by various agonists (noradrenaline, vasoactive intestinal peptide, substance P,5-hydroxytryptamine) in isolated guinea pig trachea. Although the underlying mechanisms have not been fully characterized, it was found that the NPY-evoked inhibition was specifically expressed with agents for which locally released prostaglandins (PGs) are important determinants for their myotropic activity. In the present study, we have extended these findings by examining whether NPY was capable of regulating the release of prostacyclin and thromboxane A2 induced by bradykinin (BK) from naive and ovalbumin-sensitized guinea pig perfused lungs. Our results showed that infusion of NPY (0.24 microM) through the lung significantly inhibited the release of 6-keto-PGF1 alpha (> 30%) and thromboxane B2 (50%) induced by intraarterial administration of BK (3 micrograms) from untreated and ovalbumin-sensitized guinea pig perfused lung. However, the inhibitory effect of NPY was lost in the immunological production of prostaglandins. These results suggest that NPY may act as a regulatory agent of the release of cyclooxygenase-derived products by possibly acting on events preceding phospholipase A2 activation.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

Photodynamic therapy of tumours with hexadecafluoro zinc phthalocynine formulated in PEG-coated poly(lactic acid) nanoparticles.

Hexadecafluoro zinc phthalocyanine (ZnPcF16), a second-generation sensitizer for the photodynamic therapy (PDT) of cancer, was formulated in polyethylene-glycol-coated poly(lactic acid) nanoparticles (PEG-coated PLA-NP) and tested in EMT-6 tumour-bearing mice for its photodynamic activity. The tumour response was compared to that induced by the same dye formulated as a Cremophor EL (CRM) emulsion. Formulation in the biodegradable NP improved PDT response of the tumour while providing prolonged tumour sensitivity towards PDT.

Animals↗
PubMed1996

A P1-based physical map of the Drosophila euchromatic genome.

A PCR-based sequence-tagged site (STS) content mapping strategy has been used to generate a physical map with 90% coverage of the 120-Mb euchromatic portion of the Drosophila genome. To facilitate map completion, the bulk of the STS markers was chosen in a nonrandom fashion. To ensure that all contigs were localized in relation to each other and the genome, these contig-building procedures were performed in conjunction with a large-scale in situ hybridization analysis of randomly selected clones from a Drosophila genomic library that had been generated in a P1 cloning vector. To date, the map consists of 649 contigs with an STS localized on average every 50 kb. This is the first whole genome that has been mapped based on a library constructed with large inserts in a vector that is maintained in Escherichia coli as a single-copy plasmid.

Animals↗
PubMed1996

Measurement of tumor vascular damage in mice with 99mTc-MIBI following photodynamic therapy.

The clinical perfusion agent 99mTc-MIBI was used to monitor changes in tumor vascular perfusion (TVP) induced by Photofrin (PII)-mediated photodynamic therapy (PDT). BALB/c mice bearing an EMT-6 tumor on each hind thigh were given an intravenous injection of 1, 2 or 5 mg kg-1 PII. Twenty-four hours later, one tumor was illuminated (600-650 nm, 200 mW cm-2, 400 J cm-2) while the other served as a control. At various time intervals after PDT (0, 2 and 24 h) mice received an intravenous injection of 99mTc-hexakismethoxyisobutylisonitrile (MIBI) (0.18 MBq g-1) and were sacrificed 2 min later. The light-treated and the untreated tumors were then dissected, the radioactivity was counted and the percentage of the injected dose per gram of tumor (%ID g-1) was calculated as a measure of TVP. We observed that TVP is drug dose dependent, develops progressively with time post-PDT and is inversely related to PDT efficacy. Our data show that early tumor retention of 99mTc-MIBI is a simple method to assess TVP and vascular damage induced by PDT.

Animals↗
PubMed1996

The rising prevalence of HIV-1 infection in patients attending an inner city accident and emergency department.

The recently published findings of the unlinked anonymous HIV prevalence study in England and Wales showed unchanging HIV prevalence in groups such as homo/bisexual men, and declining rates in non-injecting heterosexual men attending genitourinary medicine clinics. However, this multicentre study did detect a significant rise in seroprevalence rates in pregnant women in England and Wales and sentinel groups within hospitals in London, warning that changing patterns of HIV infection might account for these variable results. In 1992-1993 a seroprevalence study of adult patients attending the accident and emergency department at St. Mary's Hospital in West Central London showed a rate of HIV-1 infection of 1 in 77. We have repeated the seroprevalence study over the same calendar months in 1994-1995 to gain further information about HIV positive patients attending the department and to see whether a change in the patterns of HIV infection in the population served by St Mary's Hospital had occurred.

Adult↗
PubMed1996

Carpal tunnel syndrome. Effects of litigation on utilization of health care and physician workload.

We performed a study consisting of two parts to investigate the impact of litigation on patient recovery and physician workload. We received 556 replies from a questionnaire sent to hand surgeons and discovered that 98.20% of them felt that litigation increased the subjective complaints of patients. Most of these physicians (89.75%) also felt that litigation led to a worse result from treatment. Second, we undertook a retrospective chart review of 447 patients to see if there was a correlation between litigation, patient utilization of health care and physician workload. We found that workers' compensation patients with pending litigation went to the doctor's office more. They also had more letters, phone calls, and forms associated with their care, had more nerve conduction studies performed, and took longer to be discharged from care than patients with non-work-related carpal tunnel syndrome as well as workers' compensation patients who did not have pending litigation. These results indicated that litigation does affect patient utilization of health care and increases the workload on the physician.

Adult↗