Mechanically induced calcium waves in articular chondrocytes are inhibited by gadolinium and amiloride.

Chondrocytes in articular cartilage utilize mechanical signals from their environment to regulate their metabolic activity. However, the sequence of events involved in the transduction of mechanical signals to a biochemical signal is not fully understood. It has been proposed that an increase in the concentration of intracellular calcium ion ([Ca2+]i) is one of the earliest events in the process of cellular mechanical signal transduction.

Increased expression of matrix metalloproteinase-1 in osteocytes precedes bone resorption as stimulated by disuse: evidence for autoregulation of the cell's mechanical environment?

An in vivo animal model of bone adaptation was used to examine a possible role for matrix metalloproteinase-1 in the local mediation of bone remodeling: to corrode the coupling of osteocytes to the matrix in an attempt to autoregulate the cell's perception of its mechanical environment. Twelve young (12-16 months old) skeletally mature turkeys were separated into groups to be studied for stimulus periods of either 3 or 30 days. In each animal, the left ulna was functionally isolated and subjected to either disuse or 3,000 microstrain at 1 Hz for 10 minutes per day.

MR spectroscopy of bilateral thalamic gliomas.

This study reports the MR spectroscopic patterns of two patients with bithalamic glioma. In one patient, phosphorus (31P) MR spectroscopy was performed. In both patients, the proton MR spectroscopic scans showed an increased creatine-phosphocreatine peak in the tumor.

Pharmacokinetic consequences of a citalopram treatment discontinuation.

In this pilot study, the pharmacokinetics of citalopram (CIT) were examined in five hospitalized depressed patients after an abrupt discontinuation of a treatment with 40 mg/d of this selective serotonin reuptake inhibitor (SSRI). During the 8-day study period, clinical ratings were regularly carried out. Between days 5 and 8, the patients were treated with clomipramine (75 mg/d).

Categorical and coordinate spatial relations: fMRI evidence for hemispheric specialization.

Functional magnetic resonance imaging (fMRI) was applied to determine the involvement of the angular gyri in the processing of categorical and coordinate spatial relations. In a categorical task, subjects were asked to judge whether a dot was presented above or below a horizontal line. In a coordinate task, they were asked to judge whether or not the distance between the dot and the bar was within a reference distance.

Radiation therapy for consolidation of metastatic or recurrent sarcomas in children treated with intensive chemotherapy and stem cell rescue. A feasibility study.

Purpose: To assess the role of consolidative radiation therapy (CRT) in conjunction with myeloablative therapy with or without total body irradiation (TBI) in children and young adults with metastatic or recurrent sarcoma.

Methods And Materials: Twenty-one pediatric sarcoma patients with metastatic (10) or recurrent (11) disease were entered on a prospective feasibility study of intensive myeloablative therapy with or without TBI. Median patient age was 17.

Serum follicle-stimulating hormone and luteinizing hormone levels in women aged 35-60 in the U.S. population: the Third National Health and Nutrition Examination Survey (NHANES III, 1988-1994).

Objective: The objective of this study was to examine age-specific population-based values for serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels in women in the U.S. population.

The 1996 New York blizzard: impact on noninjury emergency visits.

The purpose of this study was to investigate the impact of the January 1996 New York blizzard on emergency visits to 12 Suffolk County hospitals for 10 noninjury health conditions. Emergency charts from the blizzard week (January 7-11) and a nonblizzard week (January 21-25) were reviewed and information was abstracted from the records meeting the criteria. Blizzard conditions were associated with increased visits for myocardial infarction/angina, primarily shoveling-related, and with decreased visits for asthma.

Enhancement of fracture healing by low intensity ultrasound.

Fracture healing is a highly complex regenerative process that is essentially a replay of developmental events. These events include the action of many different cell types, a myriad of proteins, and active gene expression that in the majority of cases ultimately will restore the bone's natural integrity. Several biologic and biophysical approaches have been introduced to minimize delayed healing and nonunions, some with promising results.

Effects of electromagnetic fields in experimental fracture repair.

The clinical benefits of electromagnetic fields have been claimed for 20 centuries, yet it still is not clear how they work or in what circumstances they should be used. There is a large body of evidence that steady direct current and time varying electric fields are generated in living bone by metabolic activity and mechanical deformation, respectively. Externally supplied direct currents have been used to treat nonunions, appearing to trigger mitosis and recruitment of osteogenic cells, possibly via electrochemical reactions at the electrode-tissue interface.

Childhood Lead Poisoning in Russia: A Site-specific Pediatric Blood Lead Evaluation.

Lead poisoning in children is an international concern. Health effects vary according to a child's blood lead level. Historically, the problem of lead poisoning in Russia had been defined by analysis of hair samples.

Water distribution system and diarrheal disease transmission: a case study in Uzbekistan.

Deteriorating water treatment facilities and distribution systems pose a significant public health threat, particularly in republics of the former Soviet Union. Interventions to decrease the disease burden associated with these water systems range from upgrading distribution networks to installing reverse osmosis technology. To provide insight into this decision process, we conducted a randomized intervention study to provide epidemiologic data for water policy decisions in Nukus, Uzbekistan, where drinking water quality is suboptimal.

Skeletal cell stresses and bone adaptation.

There is no tissue in which mechanical stresses have been studied in more detail than the skeletal system, this focus arising primarily because bone plays a clear structural role in the body. However, the hypothesis that the skeleton represents an optimally designed structure has contributed remarkably little to our understanding of the development and adaptive capabilities of bone tissue. Recent investigations on the consequences of mechanical, hydrostatic, and electrical stresses on the cells of bone tissue have served to redirect the discussion of bone modeling and remodeling processes.

Nonlinear dependence of loading intensity and cycle number in the maintenance of bone mass and morphology.

The daily stress stimulus theory of bone adaptation was formulated to describe the loading conditions necessary to maintain bone mass. This theory identifies stress/strain magnitude and loading cycle number as sufficient to define an appropriate maintenance loading signal. Here, we extend the range over which loading cycle number has been evaluated to determine whether the daily stress stimulus theory can be applied to conditions of very high numbers of loading cycles at very low strain magnitudes.

Cloning of a novel cDNA expressed during the early stages of fracture healing.

Using differential mRNA display (DD-PCR), a novel cDNA, FxC1 (Fracture Callus 1) was isolated from the early stages of a healing fractured femur. Utilizing 5' RACE PCR, a 598-bp full-length cDNA was obtained for FxC1 that contains an open reading frame (ORF) of 243 bp, encoding for an 80 amino acid protein. Within this ORF, a leucine zipper motif was present.

Expression of a kinase anchor protein 121 is regulated by hormones in thyroid and testicular germ cells.

Distinct A Kinase Anchor Proteins (AKAPs) immobilize and concentrate protein kinase A II (PKAII) isoforms at specific intracellular locations. AKAP121 binds and targets PKAIIalpha to the cytoplasmic surface of mitochondria. Mechanisms that control expression of this mitochondrial AKAP are unknown.

Isolation and analysis of a T cell clone variant exhibiting constitutively phosphorylated Ser133 cAMP response element-binding protein.

In driving T cell proliferation, IL-2 stimulates a new program of gene expression that includes proliferating cell nuclear antigen (PCNA), a requisite processivity factor for DNA polymerase delta. PCNA transcription is regulated in part through tandem CRE sequences in the promoter and CRE binding proteins; IL-2 stimulates CREB phosphorylation in the resting cloned T lymphocyte, L2. After culturing L2 cells for greater than 91 days, we consistently isolate a stable variant that exhibits constitutive CREB phosphorylation.

Evidence for large earthquakes in metropolitan los angeles.

The Sierra Madre fault, along the southern flank of the San Gabriel Mountains in the Los Angeles region, has failed in magnitude 7.2 to 7.6 events at least twice in the past 15,000 years.

Molecular characterization of an anchor protein (AKAPCE) that binds the RI subunit (RCE) of type I protein kinase A from Caenorhabditis elegans.

Classical A kinase anchor proteins (AKAPs) preferentially tether type II protein kinase A (PKAII) isoforms to sites in the cytoskeleton and organelles. It is not known if distinct proteins selectively sequester regulatory (R) subunits of type I PKAs, thereby diversifying functions of these critical enzymes. In Caenorhabditis elegans, a single type I PKA mediates all aspects of cAMP signaling.

Patterns of strain in the macaque ulna during functional activity.

In vivo bone strain experiments were performed on the ulnae of three female rhesus macaques to test how the bone deforms during locomotion. The null hypothesis was that, in an animal moving its limbs predominantly in sagittal planes, the ulna experiences anteroposterior bending. Three rosette strain gauges were attached around the circumference of the bone slightly distal to midshaft.

[NMR spectroscopy and brain diseases. Clinical applications].

Magnetic resonance spectroscopy (MRS) is a noninvasive means of obtaining metabolic information complementary to magnetic resonance imaging. Its potential is particularly interesting in tissue characterization and follow-up of brain lesions. We present here a review of clinical applications together with a short development of the fundamental principles.

Prevalence of hearing loss among children 6 to 19 years of age: the Third National Health and Nutrition Examination Survey.

Context: Hearing loss in children influences the development of communication and behavioral skills, but few studies in the United States have used pure-tone audiometry to derive hearing loss prevalence estimates for children.

Objective: To describe the prevalence of hearing loss among US children by sociodemographic characteristics, reported hearing loss, and audiometric screening factors.

Design: National population-based cross-sectional survey with an in-person interview and audiometric testing at 0.

[Withdrawal syndrome caused by selective serotonin reuptake inhibitors: apropos of a case].

During the past 4 years, several case reports have been published on the withdrawal syndrome which may be observed after acute interruption of a treatment with selective serotonin reuptake inhibiting antidepressants (SSRI). Paroxetine is the most frequently cited antidepressant in the literature, whereas fluoxetine is the less frequently cited of this type of drugs. The withdrawal symptoms appear a few days after stopping treatment or after a decrease of the dose.

Molecular characterization of a cDNA that encodes six isoforms of a novel murine A kinase anchor protein.

We have cloned cDNA that encodes six novel A kinase anchor proteins (collectively named AKAP-KL). AKAP-KL diversity is generated by alternative mRNA splicing and utilization of two translation initiation codons. AKAP-KL polypeptides are evident in lung, kidney, and cerebellum, but are absent from many tissues.