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Biomedical subjects

L Newman

Publications and source records attributed to L Newman.

At least 73 records · Page 4Linked to original sources
PubMed1997

A global scale to measure the quality of the family environment.

BACKGROUND: Simple, reliable measures of the quality of the environment in which a child was reared that can be used in clinical research and practice are lacking. METHOD: The reliability and validity of a global scale to retrospectively appraise the quality of that environment were examined. Fifty-three clinicians from 4 centers in Australia and 1 in Hong Kong, People's Republic of China, used the scale to rate 7 case vignettes; 4 clinicians rated 20 medical records, and 49 rated 211 subjects after clinical interviews. RESULTS: Interrater reliability (intraclass correlation coefficient) was 0.82 (time 1) and 0.84 (time 2) for case vignettes, 0.90 for medical records, and 0.89 for clinical interviews. Consistency in time was high (r = 0.91). Lower ratings, indicative of a less adequate environment, were associated with a clinical diagnosis of oppositional defiant or conduct disorder. CONCLUSIONS: Our simple-to-use scale appears to measure reliably a relevant clinical construct and fills a gap among the instruments available. Ratings may be useful as a cost-effective index to consider in outcome studies, when examining response to treatment, or in other clinical research.

Adolescent↗
PubMed1997

Social cognition in schizophrenia.

The study of social cognition in schizophrenia may augment the understanding of clinical and behavioral manifestations of the disorder. In this article, the authors describe social cognition and differentiate it from nonsocial cognition. They garner evidence to support the role of social cognition in schizophrenia: Nonsocial information-processing models are limited to explain social dysfunction in schizophrenia, measures of social cognition may contribute greater variance to social functioning than measures of nonsocial cognition, task performance on nonsocial-cognitive measures may not parallel performance on social-cognitive tasks, and symptomatology may be best understood within a social-cognitive framework. They describe the potential implications of a social-cognitive model of schizophrenia for the etiology and development of the disorder.

Cognition Disorders↗
PubMed1997

Safety and efficacy outcome of mentor alpha-1 inflatable penile prosthesis implantation for impotence treatment.

PURPOSE: We investigated safety and efficacy outcome pertaining to the Mentor Alpha-1, 3-piece inflatable penile prosthesis for impotence treatment. MATERIALS AND METHODS: A 2-phase, multi-institutional, large scale retrospective study, with independently analyzed medical record (phase I) and questionnaire (phase II) data from consecutive eligible patients of 7 physician investigators was performed from March to October 1993. RESULTS: In phase I there were no morbidities of any type in 394 of the 434 patients (90.8%) (mean age 61 years, range 24 to 88) who underwent Alpha-1 implantation (mean followup 22.2 months, range 0.67 to 44.5). The risk of prosthesis malfunction (fluid leak and auto-inflation) was 2.5%. No cylinder aneurysms were reported. A total of 93.1% of Alpha-1 devices was free from explantation (4.4%) or revision surgery (2.5%) for approximately 2 years from the original implant date. Kaplan-Meier actuarial analyses revealed that cumulative survival of the Alpha-1 prostheses at 12, 24 and 36 months was 98 +/- 1%, 93 +/- 2% and 85 +/- 7% until device malfunction, and 91 +/- 2% 83 +/- 4% and 75 +/- 7% until surgical intervention (revision or explantation). In phase II 89% of the men claimed fulfilled expectations with the Alpha-1 prosthesis as impotence treatment. Satisfaction responses 80% or greater were noted with regard to intercourse ability and confidence, and device rigidity and function. Implantation did not result in greater than 80% satisfaction in partner relationships or feelings (as judged by the patient), social or work confidence, or intercourse frequency. Factors adversely affecting satisfaction included partner feelings of dissatisfaction (as judged by the patient), specific physician investigators and need for explantation/revision surgery. CONCLUSIONS: In 1 of the largest multi-institutional implant outcome studies thus far performed, safety and efficacy data concerning the Alpha-1 contemporary inflatable device were found markedly improved over earlier inflatable prostheses and now compare favorably with historical data from noninflatable rod type devices.

Actuarial Analysis↗
PubMed1997

Photodynamic therapy of the ciliary body with tin ethyl etiopurpurin and tin octaethyl benzochlorin in pigmented rabbits.

BACKGROUND AND OBJECTIVES: The authors used a pigmented rabbit model to investigate two photosensitizers, tin ethyl etiopurpurin (SnET2) and tin octaethyl benzochlorin (BNZ 203), to determine their potential for creating ciliary body injuries during photodynamic therapy (PDT). MATERIALS AND METHODS: The biodistribution of SnET2 (n = 10) and BNZ 203 (n = 9) was studied by fluorescence microscopy using a low light detection system, based on charged-coupled device photography, with digital image processing at 1 and 24 hours after injection. PDT with SnET2 (n = 8; 664 +/- 7-nm light; 75 mW/cm2; 50 or 100 J/cm2; 1-mm spot size) and BNZ 203 (n = 6; 689 nm; 75 mW/cm2; 50 or 100 J/cm2; 1-mm spot size) was performed at 24 hours post-injection. The control subjects for SnET2 (n = 5) and BNZ 203 (n = 3) were given a maximal light dose (100 J/cm2). RESULTS: Both photosensitizers demonstrated an intravascular distribution at 1 hour that shifted to a ciliary body distribution at 24 hours (SnET2 much greater than BNZ 203). In addition, the SnET2 demonstrated suborgan localization to the nonpigmented ciliary body epithelium. Both photosensitizing agents were able to produce selective injury to the rabbit ciliary body (SnET2 much greater than BNZ 203), with evidence of a small component of thermal damage (SnET2 greater than BNZ 203). CONCLUSIONS: PDT with SnET2 or BNZ 203 can produce selective injury to the pigmented rabbit ciliary body. The nonpigmented ciliary body epithelium exhibits selective retention of SnET2. This finding warrants further investigation.

Animals↗
PubMed1996

Ischemic/reperfused myocardium can express recombinant protein following direct DNA or retroviral injection.

A non-contracting scar following myocardial infarction can adversely affect ventricular topography and hemodynamic function. Gene transfer has the potential to prevent or alter such pathophysiological processes. Normal myocardium is a proven target for delivery of DNA or viral vectors but the potential for gene therapy in ischemic myocardium has not been evaluated. In an initial series of experiments, we determined whether the direct injection of reporter genes into hearts subjected to coronary artery occlusion followed by reperfusion could result in gene expression comparable to the levels observed in non-occluded normal hearts. Anesthetized rats were subjected to 15 min or 60 min of proximal coronary occlusion or sham operation. Luciferase gene under the control of the Rous sarcoma virus promoter was injected directly into the anterior left wall. At 1 week, high expression of luciferase was observed in both the ischemic/reperfused and non-ischemic tissue. Thus DNA transfer by direct injection is possible after ischemic injury and uptake and expression are not impaired. In a second series of experiments, myocardial infarcts in dogs were injected with a beta-galactosidase expressing retroviral vector. LNPOZ. Six to 11 days later frozen sections revealed macroscopically visible expression of beta-galactosidase activity. Not only can foreign genes be taken up by direct injection of DNA or retroviruses into ischemic/reperfused myocardium but they can be transcribed and the protein synthetic machinery of the injured cells can produce recombinant polypeptides that retain enzymatic activity. These results open the way for the investigation of gene therapy in models of ischemia.

Animals↗
PubMed1995

The zinc coordination site of the bacteriophage Mu translational activator protein, Com.

The bacteriophage Mu Com protein is a small "zinc finger-like" protein that binds a specific site in com-mom operon mRNA and activates translation of the mom open-reading-frame. Com contains six cysteine and five histidine residues that have the potential to form several alternative zinc-finger-like motifs. We have used oligonucleotide site-directed mutagenesis to individually alter each of these amino acids (Cys to Ser, and His to Asn or Gln) and tested the various forms of Com for their ability to function in vivo. We observed that mutation of any one of the four N-terminal cysteine residues (Cys-6, 9, 26 or 29) resulted in loss of Com activity. The Com protein requires zinc in order to fold into its functional tertiary structure, as demonstrated by characteristic 1H nuclear magnetic resonance (NMR) chemical shifts. 1H chemical shifts revert to random coil values in the presence of the metal chelator EDTA. The metal-binding specificity and thermal stability of Com also has been investigated using 1H NMR. We report the use of 113Cd NMR, 1H-113Cd heteronuclear spin-echo difference spectroscopy HSED and Zn extended X-ray absorption fine structure spectroscopy EXAFS to determine the zinc/protein stoichiometry as 1:1 and the ligand environment as tetrathiolate. Comparative NMR spectra of Com mutants C6S and C39S suggest position 6 is involved in zinc coordination, while position 39 is not metal-liganded. These studies indicate that the metal coordination, site of Com is a four-cysteine complex, involving residues 6, 9, 26 and 29.

Amino Acid Sequence↗
PubMed1995

Adaptation of rabbit small intestinal brush-border membrane enzymes after extensive bowel resection.

Short lengths of small intestine may be resected without significantly affecting the digestive and absorptive capacity; however, extensive resection produces varying degrees of malnutrition. This study was undertaken to define the adaptive changes in the remaining small intestine of two of the jejunal and ileal mucosal brush-border membrane enzymes after extensive small bowel resection in rabbits. Thirty adult New Zealand White rabbits underwent a 50% to 60% jejuno-ileal-enterectomy with end-to-end anastomosis. Maltase activity (UE/g protein) increased from 152 (preoperative) to 392 at 3 weeks in the proximal segment and from 85 to 259 in the distal segment; these levels decreased to 222 and 155 in the respective segments at 6 weeks. AOP activity (UE/g protein) increased from 154 (preoperative) to 171 in the proximal segment and 171 to 256 in the distal segment at 3 weeks, and was 131 and 288 in the respective segments at 6 weeks. This marked increase in the mucosal brush-border enzymatic activities at 3 weeks postoperatively was associated with a 28% increase in bowel length. By 6 weeks the enzyme levels had decreased slightly; however, there was a persistent 41% increase in bowel length over that immediately postoperation. The mucosal surface area increased from 295 mm2 immediately postoperation to 5,337 mm2 at 3 weeks and 7,635 mm2 at 6 weeks, a 250% increase. The authors conclude that there is an immediate compensatory increase in villus length as well as brush-border enzymatic expression in the remaining intestine that gradually declines as the small intestinal surface area continues to increase and the bowel lengthens with time.

Adaptation, Physiological↗
PubMed1995

Malignant ameloblastoma revisited.

A case of a malignant ameloblastoma in a 49-year old Sri Lankan woman with widespread pulmonary metastases is presented, the diagnosis confirmed by needle biopsy. The current histological classification of odontogenic carcinomas and the management of metastatic pulmonary deposits are discussed.

Ameloblastoma↗
PubMed1995

Melanotic neuroectodermal tumour of infancy: an immunohistochemical and ultrastructural study.

Two cases of melanotic neuro-ectodermal tumour of infancy (MNTI)--a rare neoplasm arising in the first year of life--are reported, with the results of immunohistochemical and ultrastructural examination. The tumours consisted of a biphasic cell population in a fibrous stroma. The small, darkly staining cells comprising the first population stained positively for synaptophysin, showing them to be neuroblasts, and the large epithelioid cells comprising the second cell population stained positively with the antibodies HMB-45 and NKI-Beteb, showing them to be melanocytes. Ultrastructural examination of the second case confirmed the biphasic nature of the tumour cells, with secretory granules and neurofilaments in the neuroblastic population, and melanosomes in the epithelioid population. These results add to the evidence supporting the neural crest origin of MNTI and confirm its formation from two distinct cell lines. Both cases have responded to local excision, with no recurrence more than a year after initial treatment.

Antigens, Neoplasm↗
PubMed1995

The role of autogenous primary rib grafts in treating fractures of the atrophic edentulous mandible.

Fractures of the atrophic edentulous mandible are relatively uncommon representing less than 1% of all facial bone fractures seen at The Queen Victoria Hospital, East Grinstead. Only 35 patients have been treated for fractures of the atrophic edentulous mandible at this unit from a total of over 4000 facial bone fractures seen here between 1975 and 1994. All traditional treatment modalities have been utilised with varying degrees of success. A technique is presented whereby all displaced fractures of the atrophic edentulous mandible with a measured bony vertical dimension of less than 10 mm at the fracture site are managed with primary autogenous rib grafting. This reduces the risk for formation of pseudarthrosis and facilitates subsequent prosthetic rehabilitation.

Aged↗
PubMed1995

Laparoscopic diagnosis and treatment of Morgagni hernia.

The application of new minimally invasive techniques in the diagnosis and treatment of surgically correctable diseases continues to produce impressive results. Herniae of the Foramen of Morgagni are unusual abdominal wall defects which have historically been difficult to diagnose. Interestingly, laparoscopy was utilized for the diagnosis and repair of three such herniae during a 5-month period. All of these repairs were performed by one primary author in conjunction with co-authors. In this report we will review this rare hernia and report our technique of repair. We believe that an aggressive approach to diagnostic laparoscopy may produce cost-effective solutions to old and new intraabdominal problems.

Adult↗
PubMed1995

1525 laparoscopic cholecystectomies without biliary injury: a single institution's experience.

Laparoscopic Cholecystectomy (LC) has become the preferred treatment of gallbladder disease. The indications for LC remain unchanged from those for open cholecystectomy (OC). A total of 1525 patients underwent LC at Georgia Baptist Medical Center between December 1989 and December 1992. The procedure was completed in 1,492 patients (97.8%) and required conversion to OC in 33 patients (2.2%). Selective intraoperative cholangiography was used in 165 patients (10.8%). Overall morbidity was 4.06%, and there were four deaths not operatively related, for a 0.26% mortality rate. There have been no biliary ductal injuries. The average hospital stay was 0.82 days, with 37.4% of the patients going home as true outpatients and 44.5% going home on postop Day one. Most published series on LC report a small incidence of biliary injury. We feel that with meticulous dissection of the cystic duct and use of selective intraoperative cholangiography to define unsure anatomy, biliary injury can be minimized.

Biliary Tract↗
PubMed1994

Tissue restricted gene expression assayed by direct DNA injection into cardiac and skeletal muscle.

We have used direct injection of plasmid DNA into heart and tongue in vivo and transfection into cells in culture to determine (1) whether the pattern of reporter gene expression parallels the cell-type specific expression of endogenous genes, (2) whether the pattern of reporter gene expression approximates that of the same constructs transfected into myocardiocytes and myogenic cells in culture, (3) whether the expression patterns of promoters and enhancers that had been subtly altered by mutations are similar following transfection and direct DNA injection. We utilized reporter gene constructs derived from the two fiber-type specific human troponin C genes: the fast twitch gene (TnCf) and the slow twitch or cardiac gene (cTnC). The endogenous TnCf gene does not express in the heart and the plasmid DNA expresses neither in myocardium after injection nor in transfected cardiomyocytes. However injected TnCf does express vigorously in tongue muscle. Conversely, the endogenous cTnC gene does not express in fast twitch skeletal muscles like tongue and the plasmid DNA does not express in tongue after injection. However, injected cTnC does express in both injected myocardium and in transfected cardiomyocytes. With few discrepancies, various deletions and alterations of the promoters and enhancers of these genes that have previously been defined by transfection into permissive myogenic cells in culture gave parallel expression patterns after injection in myocardium and tongue. Thus we conclude that direct DNA injection appears to provide a method to verify the identities of important cis-acting regulatory regions that have been mapped in cells in culture.

Animals↗