Search PubMed⌕ Search

Biomedical subjects

D Griffith

Publications and source records attributed to D Griffith.

At least 37 records · Page 2Linked to original sources
PubMed1993

Characterization of the effects of lithium on phosphatidylinositol (PI) cycle activity in human muscarinic m1 receptor-transfected CHO cells.

1. The effects of lithium on [3H]-inositol and [3H]-cytidine incorporation into [3H]-inositol monophosphates ([3H]-InsP1) and [3H]-cytidine monophosphorylphosphatidate ([3H]-CMP-PA), respectively, and inositol 1,4,5-trisphosphate (InsP3) and inositol 1,3,4,5-tetrakisphosphate (InsP4) mass were studied in carbachol-stimulated human m1 muscarinic receptor-transfected Chinese hamster ovary cells (m1 CHO cells). 2. Lithium alone (10 mM) had no appreciable effects on any of the four parameters measured; it was only in carbachol-stimulated cells that the effects of lithium became apparent. 3. In the presence of carbachol (1 mM), lithium (10 mM) caused a relatively rapid (within 5 min) accumulation of [3H]-InsP1 and [3H]-CMP-PA which continued up to about 20-30 min, after which accumulation slowed down. On the other hand, the elevation in InsP3 and InsP4 levels produced by carbachol was not altered by lithium in the short-term and only at later times (> 20-30 min) was the response attenuated, with InsP3 and InsP4 levels approaching basal. 4. The effects of lithium on carbachol-stimulated [3H]-InsP1 and [3H]-CMP-PA accumulation and the attenuation of the carbachol-induced elevation of InsP3 and InsP4 were all dose-dependent, with EC50s in the region of 1 mM. 5. The lithium-induced effects on [3H]-CMP-PA and InsP3 and InsP4 in carbachol-stimulated cells could be reversed, in a dose-dependent manner, by preincubation with exogenous myo-inositol (EC50 = 2-3 mM) but not by the inactive analogue scyllo-inositol, indicating that these effects occur as a consequence of depletion of inositol. 6. The temporal effects of lithium are consistent with lithium inhibiting inositol monophosphatase,causing accumulation of InsP1, resulting in lower free inositol levels. This leads to accumulation of CMP-PA and reduced PI synthesis which, once agonist-linked membrane inositol phospholipids are depleted, produces attenuated InsP3 and InsP4 responses.7. These results in ml CHO cells support the hypothesis that lithium affects the PI cycle cell signalling pathway by depletion of inositol due to inhibition of inositol monophosphatase.

Animals↗
PubMed1993

Approach to adult respiratory distress syndrome and respiratory failure in elderly patients.

Because of physiologic changes associated with aging and the development of chronic illness, the elderly will continue to be at risk for catastrophic illnesses including adult respiratory distress syndrome (ARDS). Current management of elderly patients with ARDS is only supportive and focused on avoiding complications. Truly successful management of these patients requires therapies directed at pathophysiologic initiators and mediators of ARDS.

Aged↗
PubMed1992

Normal uptake in a gravid uterus on Tc-99m DTPA imaging.

A 17-year-old female kidney transplant patient was admitted to the hospital with a fever and right lower quadrant pain. Although she was 14 weeks' pregnant, renal DTPA imaging was performed because graft rejection was suspected. The study revealed fetal uptake of DTPA medial to the transplanted kidney. This has not been previously reported. Uptake in a normal uterus has been described using Tc-99m pertechnetate, Tc-99m glucoheptonate, and Tc-99m MDP. It is essential to recognize uptake in the gravid uterus and to differentiate it from uptake secondary to a pathologic entity.

Adolescent↗
PubMed1992

Elevated levels of NAP-1/interleukin-8 are present in the airspaces of patients with the adult respiratory distress syndrome and are associated with increased mortality.

The adult respiratory distress syndrome (ARDS) is characterized by increased neutrophils within the airspaces of the lungs. In order to determine if neutrophil activating protein (NAP)-1/interleukin-8 (NAP-1/IL-8) could be an important cause of neutrophil influx and activation in ARDS, we examined fluid, which was either directly aspirated or lavaged with saline from the lungs of patients with ARDS. NAP-1/IL-8 was present in significantly higher concentrations in the fluids of patients with ARDS compared with control subjects. There was a significant correlation between the percentage of neutrophils in the lavage fluids and the NAP-1/IL-8 concentration (r2 = 0.74). Furthermore, the NAP-1/IL-8 concentration of the pulmonary edema fluid was equivalent to the optimal concentration required to induce neutrophil chemotaxis in vitro. Although not all of the chemotactic activity of the edema fluid was removed by an anti-NAP-1/IL-8 affinity column, the data established that NAP-1/IL-8 is an important neutrophil chemotaxin in the airspaces of patients with ARDS. In addition, those patients with very high concentrations of NAP-1/IL-8 in their bronchoalveolar lavage fluids had a higher mortality rate than those patients with lower concentrations of NAP-1/IL-8. The correlation between NAP-1/IL-8 concentration and mortality is not paralleled by total protein concentration and mortality.

Adolescent↗
PubMed1990

Computer access for persons who are blind or visually impaired: human factors issues.

Suitably adapted computers hold considerable potential for integrating people who are blind or visually impaired into the mainstream. The principal problems that preclude the achievement of this potential are human factors issues. These issues are discussed, and the problems presented by icon-based interfaces are reviewed. An argument is offered that these issues, which ostensibly pertain to the blind or visually impaired user, are fundamental issues confronting all users. There is reason to hope that the benefits of research into the human factors issues of people with vision impairments will also extend to the sighted user.

Blindness↗
PubMed1988

A peptide from alveolar macrophages that releases neutrophil enzymes into the lungs in patients with the adult respiratory distress syndrome.

A monoclonal antibody has been made to a peptide that is released by human alveolar macrophages. This enzyme-releasing peptide (ERP) causes neutrophils to secrete azurophilic granule enzymes. Normal subjects, patients with pulmonary fibrosis, and patients with sarcoidosis had similar concentrations of this peptide in their bronchoalveolar lavage fluids. However, patients with the adult respiratory distress syndrome (ARDS) had about 2.7 times higher concentrations in their lavage fluids. The enzyme-releasing activity in the lavage fluids was significantly correlated with 2 indices of the severity of the clinical illness in patients with ARDS, the APACHE score, and the chest radiograph score. The correlation was diminished or ablated by removing the peptide with the monoclonal antibody bound to staphylococcal Sepharose 4B. This peptide accounted for 62.08% (SD = 15.88%) of the enzyme-releasing activity in fluids from lungs of patients with ARDS and 86.39% (SD = 24.46%) of the activity in fluids from lungs of normal control subjects. Therefore, ERP is the major neutrophil enzyme-releasing agent in the bronchoalveolar lavage fluid from patients with ARDS and from normal persons. There was a significant correlation between the neutrophil enzyme-releasing activity and the ERP concentrations in BAL of patients with ARDS. These observations suggest that modulation of neutrophil function by ERP significantly controls the protease and peroxidase loads in the lungs of patients with ARDS.

Adolescent↗
PubMed1986

Report of the United States cooperative study of extracorporeal shock wave lithotripsy.

Extracorporeal shock wave lithotripsy effectively fragments urinary calculi in the upper urinary tract and upper ureter. These fragments pass completely by 3 months in 77.4 per cent of the patients with single stones. Risk of obstruction, increased postoperative pain, need for additional urological operations and retained fragments are low for stones less than 1 cm. in size. As the number of stones treated or single stone size increases above 1 cm. the risk for these factors increases. Adjunctive urological surgical management is required in 9 per cent of the patients preoperatively and 8 per cent postoperatively. Only 0.6 per cent of the patients require some type of open operation to resolve the stone problems after extracorporeal shock wave lithotripsy. Hemorrhage, obstruction by fragments, severe pain and urinary infection all constitute known complications and require careful urological management of all patients. Hospitalization averages 2 days after treatment and patients usually return to work within a few days after they are discharged from the hospital.

Adult↗
PubMed1986

Peasants in reserve: temporary West Indian labor in the U.S. farm labor market.

In the past 10 years, the British West Indies Temporary Alien Labor Program has received widespread judicial and legislative support and criticism. While sugar and apple producers who import West Indians argue that domestic labor is insufficient to harvest their crops, labor organizations and their supporters maintain that domestic labor is adequate. The resulting labor disputes focus primarily on the issue of whether or not West Indians are displacing US workers or undermining wage rates and working conditions. This article examines the relationships among legal issues surrounding the program, the US farm labor market, and the Jamaican peasantry. It argues that continued imports of foreign labor during times of high domestic unemployment, as well as the varied factors which underlie the continued willingness and ability of Jamaican peasant households to supply workers to US producers, can be most clearly understood from an international and historical perspective, rather than focussing on the needs and problems of any 1 nation.

Agriculture↗
PubMed1983

Assay of urinary oxalate: six methodologies compared.

To assess how well results by different methods for urinary oxalate determinations agree with each other in a clinical setting, we compared six different assays: Hodgkinson and Williams (Clin Chim Acta 36:127-132, 1972), enzymatic, modified Hodgkinson and Williams, gas chromatography, ion chromatography, and "high-pressure" liquid chromatography. For the entire group of samples, the mean value by each method agreed relatively closely, although the enzymatic procedure produced a somewhat higher value. All six methods had large coefficients of variation within (8-58%) and between (15-88%) assays. In addition, analytical recovery by most assays was more than 100% of the added oxalate. Analytical recovery of 10 micrograms of oxalate added per milliliter of urine specimen ranged from 86 to 237%; for 20 micrograms/mL it was 83 to 320%. Thus for the six methods evaluated, no single method appeared to be superior to the others.

Chromatography, Gas↗
PubMed1981

Comparison of the antihypertensive effects of indapamide and cyclopenthiazide.

The antihypertensive effects of indapamide, 2.5 mg, and cyclopenthiazide, 0.5 mg daily were compared over a two week period. The falls in both diastolic and systolic blood pressure were greater with indapamide than with cyclopenthiazide reaching statistical significance for the supine diastolic values. This difference was still seen when matching patient groups of similar age, sex or severity of blood pressure were compared.

Antihypertensive Agents↗
PubMed1979

The assay of prekallikrein activator in human blood products.

An assay for the determination of prekallikrein activator (PKA) in human blood products is described. Kallikrein released from a prekallikrein substrate preparation by PKA in the sample is determined using the synthetic substrate S-2302 (H-D-Pro-Phe-Arg-pNA). The PKA content of the sample is quantitated by interpolation from a standard line obtained using a reference preparation of plasma protein fraction (PPF). Endogenous kallikrein is estimated and an adjustment made for its contribution to the apparent PKA content of the sample. The results of determinations on a number of PPF, immunoglobulin and coagulation factor preparations are presented and discussed.

Blood Proteins↗
PubMed1977

Metabolic effects of sodium restriction and thiazides in tetraplegic patients.

The metabolic effects of sodium restriction, alone or with thiazide, were studied in 12 healthy subjects, in 24 tetraplegics during the intial 8 months of paralysis (early) and in 16 others during the subsequent period (late). The diuresis caused by both treatments led to more haemoconcentration in early than in late patients. In contrast with the healthy subjects on low sodium, the tetraplegics had a delayed urinary sodium retention and no fall in calciuria. During thiazide, urinary sodium depletion occurred early and the urine calcium fell after 3 days in all tetraplegics. During both treatments, aldosterone and renin increased more in early patients than in the other groups. The clinical implications of inducing dehydration and a sustained stimulation of the renin-angiotensin-aldosterone axis in recently injured tetraplegics with severe orthostatic hypotension are discussed.

Adolescent↗