Neuropathological findings in the very old. Results from the first 101 brains of a population-based longitudinal study of dementing disorders.

We report a unique longitudinal epidemiological study of cognitive decline in the elderly population of the city of Cambridge, UK. A population sample of people aged 75 and over was surveyed between 1984-1996 (n = 2,616) and followed 2.4, 6, and 9 years later.

Human zona pellucida micromanipulation and monozygotic twinning frequency after IVF.

To assess the association of zona pellucida micromanipulation and subsequent development of monozygotic twins, cases of assisted embryo hatching (AH) and intracytoplasmic sperm injection (ICSI) were identified and related to treatment type, implantation and zygosity data. Embryology records from all patients undergoing in-vitro fertilization (IVF) at this centre from January 1995 to March 1998 were reviewed. In this study, 3546 transfer cycles were completed, with clinical pregnancy established in 1911 (54% per transfer) patients undergoing a single IVF cycle.

Estimating the true extent of cognitive decline in the old old.

Objective: To measure cognitive change using a brief measure over a period of 9 years and to adjust for attrition in the sample.

Design: The Cambridge City over 75 Cohort (CC75C), a complete sample of the 75 years and older age group from five group general practices in the city of Cambridge with a systematic one-third of a further practice, all followed on four occasions.

Setting: Cambridge city, UK, the respondents' place of residence.

A prospective, randomized comparison of ovulation induction using highly purified follicle-stimulating hormone alone and with recombinant human luteinizing hormone in in-vitro fertilization.

The commercial availability of highly purified, s.c. administered urinary follicle stimulating hormone (FSH) preparations for ovarian stimulation marked the beginning of a new era in the treatment of infertility.

Adsorption of vitamin K-dependent proteins to live cell membranes measured under flow conditions.

Mechanisms mediating initial adsorption of coagulation proteins to live cells were investigated. Adsorption kinetics were examined under varying flow conditions using tracer-dilution techniques in perfused spherical monolayers of cells expressing tissue factor. At biologically relevant time and concentration ranges, rates exceeded by 2-12 fold the theoretical maximum calculated for steady-state diffusion.

Surface texturing and coating of biomaterial implants: effects on tissue integration and fibrosis.

To determine whether texturing and coating have additive effects in promoting tissue integration and inhibiting fibrosis, we evaluated smooth silicone rubber (SSR), textured silicone rubber (TSR), porous silicone rubber (PSR), expanded polytetrafluoroethylene (ePTFE), and porous polyurethane (PPU) subcutaneous implants in eight minipigs. Some of the implants were coated with type IV collagen (Col) and/or fibronectin (Fn). At 6 months, we removed the implants and examined them microscopically.

Ossiculoplasty.

Homograft human bone is not only the most logical choice for grafting material, but also the closest transplantation material to the host histologically. This article discusses surgical repair of the ossicular chain with homograft bone transplants, including rationale for present surgical techniques, a thorough description of simple methods of microlathing homograft bone grafts, and instructions for maintaining an ossicular replacement bone bank. Furthermore, results in all types of ossiculoplasty and a method of classification of tympanoplasty are presented in this article.

Electrostatic interactions during activation of coagulation factor IX via the tissue factor pathway: effect of univalent salts.

Interaction between the Gla-domain of coagulation proteins and negatively charged phospholipid membranes is essential for blood coagulation reactions. The interaction is calcium-dependent and mediated both by electrostatic and hydrophobic forces. This report focuses on the electrostatic component of factor IX activation via the extrinsic pathway.

Abdominal hysterectomy practice patterns in the United States.

Objective: To describe nationwide practice trends for two principal techniques of abdominal hysterectomy in the United States, numbers and rates of total (TAH) and supracervical (SCH) hysterectomy were reviewed with charges for each operation.

Methods: Practice patterns for all inpatient TAH and SCH discharges in the US from 1991 to 1994 were studied using HCUP-3 NIS, a nationwide hospital discharge database. Hysterectomies performed for malignant disease, vaginally or with laparoscopic assistance were not sampled.

Supracervical and total abdominal hysterectomy trends in New York State: 1990-1996.

To describe practice trends for total abdominal hysterectomy (TAH) and supracervical abdominal hysterectomy (SCH) in New York State and to identify fiscal features associated with these two operations, all inpatient discharges for TAH and SCH performed for benign indications from 1990 to 1996 were reviewed using the Statewide Planning and Resource Cooperative System, a centralized data reporting system. For each year examined, the number of TAHs and SCHs performed, the procedure rates adjusted for the total New York State female population, and the per diem charge (calculated from mean institutional charge as a function of average length of stay) were evaluated. While the TAH rate declined in New York State, from 34.

U-shape relationship between change in dietary cholesterol absorption and plasma lipoprotein responsiveness and evidence for extreme interindividual variation in dietary cholesterol absorption in humans.

A possible relationship between change in dietary cholesterol absorption and plasma lipoprotein responsiveness was examined in 18 normal subjects fed low fat low cholesterol, high fat low cholesterol, and high fat high cholesterol diets. For the group, neither dietary cholesterol nor dietary fat affected the percentage dietary cholesterol absorption, whereas dietary cholesterol intake raised total and LDL-C and dietary fat raised total, LDL, and HDL-C. On a fixed diet there was approximately a 2-fold variation among subjects in percentage dietary cholesterol absorption.

The Semliki Forest virus vector induces p53-independent apoptosis.

Three deletion mutants of the structural protein region of the Semliki Forest virus (SFV) genome, including one which encompassed all the viral structural protein genes, induced apoptosis in BHK cells at 48 h after transfection, as shown by DNA laddering and TUNEL staining, as did the wild-type SFV4 RNA. A similar result was obtained for the SFV1 expression vector, which has a multicloning site inserted in place of the structural protein genes. However, in cells transfected with viral RNA containing a deletion of the nsP2 gene, neither viral RNA synthesis nor the induction of apoptosis occurred.

Hydration structure of antithrombin conformers and water transfer during reactive loop insertion.

The serine protease inhibitor antithrombin undergoes extensive conformational changes during functional interaction with its target proteases. Changes include insertion of the reactive loop region into a beta-sheet structure in the protein core. We explore the possibility that these changes are linked to water transfer.

Lung cancer among Chinese females in Singapore 1968-1992: time trends, dialect group differences and implications for aetiology.

Background: Chinese females are distinguished internationally as having relatively high lung cancer incidence rates despite a low prevalence of cigarette smoking. In Singapore, this population comprises several dialect groups which have origins in different regions in China, each with its own traditional cultural practices.

Methods: An analysis of 4029 incident cases of the disease notified to the Singapore Cancer Registry for 1968-1992 was undertaken to provide some insight into important aetiologic factors among these women.

The impact on prevalence of dementia in the oldest age groups of differential mortality patterns: a deterministic approach.

Background: Until recently relatively little data have been available on the prevalence of dementia in the oldest age groups, and yet it is these age groups which are expanding fastest. It is therefore important to understand whether the prevalence of dementia rises inexorably with age ('age-dependent'), or, as some suggest, levels off or even declines in the very oldest age groups ('age-related'). Combined analysis of the many prevalence studies now available has led to modelled curves which do suggest a slowing of rise in prevalence at these great ages, and has been interpreted as meaning that dementia is age-related.

Effective electrostatic charge of coagulation factor X in solution and on phospholipid membranes: implications for activation mechanisms and structure-function relationships of the Gla domain.

Electrostatic interactions during activation of coagulation factor X were analysed by comparing effects of ionic strength on reaction rates with predictions of classical electrostatic theory. Geometrical correlations were investigated using alpha-shape-based computations on the crystal structure of Ca-fragment 1 of prothrombin. The ionic strength of the reaction environment was controlled with different univalent salts including NaCl, KCl, CsCl, LiCl, NaI, NaBr and KI.

Examination of the validity of the hierarchical model of neuropathological staging in normal aging and Alzheimer's disease.

The neuropathological staging model of Alzheimer's disease proposed by Braak and Braak [Acta Neuropathol (1991) 82:259] requires that the evolution of neurofibrillary pathology follows a predictable pattern that can be ordered in a regular regional hierarchy. We have operationalized the neuropathological staging system to permit testing of its validity. Forty-two cases were derived from an epidemiological study of cognitive function in an elderly population for which post-mortem brain tissue was collected.

Death mechanisms in cultured cells infected by Semliki Forest virus.

We have investigated the induction of cell death in cultured cells by the virulent SFV4 and avirulent A7 strains of Semliki Forest virus (SFV). In BHK cells, death occurred by a typical apoptotic mechanism, as did the death of oligodendrocytes in glial cell cultures. For cerebellar neuron cultures, virus-induced death was due to necrosis.

Temporal lobe perfusion asymmetries in schizophrenia.

Unlabelled: Structural and functional neuroimaging techniques have consistently demonstrated that abnormal lateralization of temporal lobes may be important in identifying the pathophysiologic processes in schizophrenia. The exact nature of these reported abnormalities has not been consistent.

Methods: We examined temporal lobe perfusion using HMPAO-SPECT in 22 individuals with schizophrenia in an effort to establish whether temporal lobe perfusion asymmetry is seen in these individuals, as compared to a group of 22 age- and sex-matched controls.

Rethinking patient placement: the human service matrix model for matching services to needs.

The improvements in both clinical and fiscal outcomes necessary for prosperity in the current healthcare environment require a rethinking of our conceptual approaches to patient assessment, treatment planning, and service delivery. Conventional practice rests in part on the Level of Care concept, which assigns intensities of both clinical services and treatment settings in a linked manner according to impairment severity. Although this approach has resulted in more efficient matching of resources to needs, it is overly restrictive, and does not speak directly to the need to match both healthcare and social services (including treatment setting) to human needs for treatment to be successful.

The role of polyethylene wear in joint replacement failure.

Aseptic loosening is the major cause of failure of joint replacement prostheses. Polyethylene implants removed at revision surgery regularly show wear. It is proposed that the polyethylene particles released into the tissues as a consequence of this wear induce a tissue response that precedes aseptic loosening.