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Biomedical subjects

E Jacob

Publications and source records attributed to E Jacob.

At least 37 records · Page 2Linked to original sources
PubMed1999

Making the transition from hospital to home: caring for the newly diagnosed child with cancer.

Current trends in the management of health care show increasing pressure for earlier discharge of children, and their families may or may not be ready to continue the child's care at home. This article provides information that helps the home care provider bridge the transition from hospital care to home care. Care frequently is coordinated by a hospital-based clinical nurse specialist who provides psychosocial support, reinforces teaching, minimizes risks for complications, and performs home infusion therapy, such as antibiotics, chemotherapy, analgesics, total parenteral nutrition, and biologic therapy.

Child↗
PubMed1999

Prevalence of diabetes and ethnic differences in cardiovascular risk factors. The 1992 Singapore National Health Survey.

OBJECTIVE: The purpose of the 1992 Singapore National Health Survey was to determine the current distribution of major noncommunicable diseases and their risk factors, including the prevalence of diabetes and dyslipidemia, in Singapore. RESEARCH DESIGN AND METHODS: A combination of disproportionate stratified sampling and systematic sampling were used to select the sample for the survey. The final number of respondents was 3,568, giving a response rate of 72.6%. All subjects fasted for 10 h and were given a 75-g glucose load, except those known to have diabetes. Blood was taken before and 2 h after the glucose load. Diagnosis of diabetes was based on 2-h glucose alone. RESULTS: The age-standardized prevalence of diabetes in Singapore residents aged 18-69 years was 8.4%, with more than half (58.5%) previously undiagnosed. Prevalence of diabetes was high across all three ethnic groups. The prevalence of impaired glucose tolerance was 16.1%, that of hypertension was 6.5%, and 19.0% were regular smokers. The total cholesterol (mean +/- SD) of nondiabetic Singaporeans was 5.18 +/- 1.02 mmol/l; 47.9% had cholesterol > 5.2 mmol/l, while 15.4% had levels > 6.3 mmol/l. Mean LDL cholesterol was 3.31 +/- 0.89 mmol/l; HDL cholesterol was 1.30 +/- 0.32 mmol/l, and triglyceride was 1.23 +/- 0.82 mmol/l. CONCLUSIONS: Prevalence of diabetes was high across all three ethnic groups. Ethnic differences in prevalence of diabetes, insulin resistance, central obesity, hypertension, smoking, and lipid profile could explain the differential coronary heart disease rates in the three major ethnic groups in Singapore.

Adolescent↗
PubMed1997

Genomic organization of the zinc-endopeptidase astacin.

The crayfish digestive protease astacin is the first described member of the astacin family of zinc-endopeptidases, for which it is regarded as a prototype. We have isolated and characterized the genomic sequence of astacin which spans a region of 2616 bp. The coding sequence is distributed over five exons and is interrupted by four introns. It was observed that structurally and functionally essential units of the protein, like the three alpha-helices, the five beta-strands, the Zn-binding motif, and the Met turn are never disrupted by introns. The start site of transcription was determined by primer extension analysis, confirming the existence of a pre-pro-protein of 49 amino acids which so far had not been detectable at the protein level. In addition, when compared to the amino acid sequence of mature astacin, a carboxy-terminal extension of two additional amino acids was also found. The exon-intron pattern of the astacin gene was compared to those of three other astacin family members with known genomic sequences, i.e., tolloid of Drosophila, the fish hatching enzyme LCE, and the human BMP1 gene. In each of the four proteins one intron was found to be inserted in the codon for a similar Gly residue which is highly conserved in this position within the astacin family.

Amino Acid Sequence↗
PubMed1997

Delayed local treatment of rabbit tibial fractures with biodegradable cefazolin microspheres.

The prevention of infection is a primary objective in the treatment of open fractures. The objective of this study was to compare the efficacy of biodegradable, poly (DL-lactide-co-glycolide) cefazolin microspheres and free cefazolin powder in Staphylococcus aureus contaminated rabbit tibial fractures when treatment was delayed for 2 hours. Fractures were produced in the tibia of rabbits, inoculated with Staphylococcus aureus, and 2 hours later treated by either direct local application of cefazolin microspheres or an equivalent dose of free cefazolin powder. Control animals did not receive antibiotic therapy. The fractures then were stabilized with a bone plate, and the animals were observed for 8 weeks. Local antibiotic therapy with biodegradable cefazolin microspheres prevented the establishment of infection in all animals, and cultures of the tibiae were sterile in all cases. In contrast, clinical evidence of infection developed in 50% of the rabbits that had been treated with free cefazolin powder and 71% of the control animals. Staphylococcus aureus was recovered from the tibiae of 75% and 100% of these animals, respectively. The results of this study suggest that local antibiotic therapy with biodegradable, controlled release cefazolin microspheres may be useful for the management of open fractures in humans, even when treatment is delayed for several hours after bacterial contamination.

Animals↗
PubMed1996

Combined corticosteroid and catecholamine stimulation of aqueous humor flow.

PURPOSE: Epinephrine is known to stimulate aqueous humor flow in humans. Corticosteroids are known to augment the effect of beta-adrenergic agonists on the ciliary body. This experiment was carried out to determine whether a corticosteroid can increase the stimulatory effect of epinephrine on aqueous humor flow. METHODS: Twenty human volunteers were studied for 24 hours. Hydrocortisone was given orally and epinephrine was given intravenously during sleep while aqueous flow was monitored. Flow was compared with a second 24-hour study when oral and intravenous placebos were given. The sequence of administration was randomized. Subjects and investigators were masked. The flows also were compared with a previously published study in which the same dose of epinephrine was administered without steroid. RESULTS: Epinephrine plus hydrocortisone compared with placebos increased aqueous flow 42% in subjects during sleep. The combination of epinephrine and hydrocortisone was a more potent stimulus to aqueous flow than epinephrine alone, which increased aqueous flow by only 27% (P = 0.045). CONCLUSION: The two major hormones of the adrenal gland work in concert to increase the rate of aqueous humor flow in humans.

Administration, Oral↗
PubMed1996

Comparison of the effect of inhaled nitric oxide and intravenous nitroglycerine on hypoxia-induced pulmonary hypertension in pigs.

Pulmonary hypertension is usually treated with intravenous (i.v.) vasodilators, but their use is limited by systemic effects. In the current study, we compared the effects of inhaled nitric oxide and intravenous nitroglycerine on pulmonary and systemic haemodynamic responses as well as on gas exchange measurements in anaesthetized pigs whose pulmonary pressure was increased by hypoxia (FiO2 = 15%). Both treatments reduced pulmonary pressure to the control level. Inhaled nitric oxide did not affect systemic arterial pressure but intravenous nitroglycerine decreased it from 126.2 to 108.8 mmHg (P = 0.04). Unlike intravenous nitroglycerine, inhaled nitric oxide increased arterial PaO2 from 5.3 to 5.9 kPa (P = 0.02). Both treatments diminished central venous pressure and left atrial pressure, suggesting a possible cardiac effect. Inhaled nitric oxide was shown to be a potent pulmonary vasodilator which attenuated pulmonary hypertension and improved arterial oxygenation without important direct effects on systemic pressure in porcine hypoxia-induced pulmonary hypertension.

Administration, Inhalation↗
PubMed1995

Surges of muscle sympathetic nerve activity during obstructive apnea are linked to hypoxemia.

Obstructive sleep apnea (OSA) is associated with oscillations of arterial blood pressure (BP) that occur in phase with irregularities of respiration. To explore the role of the sympathetic nervous system in these responses, we studied muscle sympathetic nerve activity (MSNA; peroneal microneurography), an index of vasoconstrictor nerve traffic, and BP during awake regular breathing and during spontaneous apneas in patients with OSA. To determine the role of the arterial chemoreflex, we also examined the effects of 100% O2 (hyperoxia) on MSNA and BP. In awake regularly breathing patients with OSA (n = 12), resting MSNA was markedly higher than in an age-matched control population (n = 15) [41 +/- 23 (SD) vs. 24 +/- 17 bursts/min; P < 0.05] and was unchanged during hyperoxia (n = 9). Apneas during sleep (n = 8) were associated with surges in MSNA followed by transient rises in BP when breathing resumed. In contrast to room air apneas, hyperoxic apneas of similar duration were associated with attenuated MSNA responses (+82 +/- 84% vs. +5 +/- 25% compared with awake baseline; P < 0.05; n = 6), even though O2 did not affect sleep stage and the occurrence of arousal. Thus the BP oscillations that occur with apnea during sleep may in part be mediated by intermittent surges of sympathetic activity resulting in vasoconstriction. Because the MSNA responses to obstructive apnea are blunted during O2 administration, they appear to be linked to intermittent arterial hypoxemia and stimulation of arterial chemoreceptors.

Adult↗
PubMed1994

Molecular characterization of human and bovine endothelin converting enzyme (ECE-1).

A membrane-bound protease activity that specifically converts Big endothelin-1 has been purified from bovine endothelial cells (FBHE). The enzyme was cleaved with trypsin and the peptide sequencing analysis confirmed it to be a zinc chelating metalloprotease containing the typical HEXXH (HELTH) motif. RT-PCR and cDNA screens were employed to isolate the complete cDNAs of the bovine and human enzymes. This human metalloprotease was expressed heterologously in cell culture and oocytes. The catalytic activity of the recombinant enzyme is the same as that determined for the natural enzyme. The data suggest that the characterized enzyme represents the functional human endothelin converting enzyme ECE-1.

Amino Acid Sequence↗
PubMed1993

Evaluation of biodegradable cefazolin sodium microspheres for the prevention of infection in rabbits with experimental open tibial fractures stabilized with internal fixation.

Immediate internal fixation of severe open tibial fractures usually is contraindicated due to the high risk of infection. The objective of this study was to evaluate the efficacy of local antibiotic therapy with biodegradable poly-(DL-lactide-co-glycolide) cefazolin-loaded microspheres for the prevention of infection in experimental open fractures stabilized with internal fixation. Rabbits with experimental tibial fractures that were contaminated with Staphylococcus aureus were treated with local application of cefazolin microspheres, an equivalent local dose of free Ancef powder, or systemic Ancef therapy. The bones then were fixed with a four-hole plate, and the animals were observed for 8 weeks. Clinically, deep infection was present in 86% of control animals that received no antibiotics and in 60% of animals that received a 7 day course of systemic Ancef therapy. In contrast, no infections were noted among any of the surviving rabbits that received local therapy with either cefazolin microspheres or free Ancef powder. Significantly higher levels of serum cefazolin were measured at 1 h for animals treated with free Ancef powder (18.7 +/- 6.1 micrograms/ml) than for those treated with cefazolin microspheres (0.57 +/- 0.27 micrograms/ml). Follow-up studies are in progress to evaluate further the potential clinical benefits of local antibiotic therapy for the management of contaminated open fractures in humans.

Animals↗
PubMed1993

An unusual cause for cyanosis.

Cyanosis is a common physical sign in clinical medicine. Cardiac or respiratory conditions are the usual causes. We report a patient with an unusual cause for cyanosis and highlight the salient clues that lead to the diagnosis.

Adult↗
PubMed1992

A retrospective analysis of open fractures sustained by U.S. military personnel during Operation Just Cause.

A retrospective analysis was conducted of 37 open fracture cases sustained by U.S. military personnel during the recent low-intensity conflict in Panama (Operation Just Cause). The etiology, location, classification, and management of open fractures sustained in combat is presented. A significant difference was noted in the infection rate for type III open fractures that were debrided in Panama (22%) as compared to those that were debrided only after transport to CONUS (66%). This study supports the critical importance of adequate battlefield surgical support in low-intensity conflicts, and reemphasizes the crucial role of early surgical debridement for the prevention of wound infection.

Adolescent↗
PubMed1991

Urokinase-type and tissue-type plasminogen activators are essential for in vitro invasion of human melanoma cells.

This study evaluates the contribution of two types of plasminogen activators (PAs; tissue-type PA (tPA) versus urokinase-type PA (uPA) toward the invasiveness of human melanoma cells in a novel in vitro assay. We identified two human melanoma cell lines, MelJuso and MeWo, expressing uPA or tPA as shown at mRNA, protein, and enzyme activity level. MelJuso cells produced uPA as well as plasminogen activator inhibitor-1 (PAI-1). The latter was, however, not sufficient to neutralize the cell-associated or secreted uPA activity. MeWo cells secreted tPA, but the enzyme was not found to be cell-associated. PAI-1 production by these cells was not detectable. Plasminogen activation and fibrinolytic capacity of both cell lines were reduced by anticatalytic monoclonal antibodies specific for the respective type of PA or by aprotinin. In a novel in vitro invasion assay, antibodies to PA as well as aprotinin decreased the invasiveness of both cell lines into a fibrin gel, Matrigel, or intact extracellular matrix. Our results confirm the importance of uPA-catalyzed plasminogen activation in tumor cell invasiveness. Furthermore, we provide evidence that tPA, beyond its key role in thrombolysis, can also be involved in in vitro invasion of human melanoma cells.

Collagen↗
PubMed1991

Overnight (1 mg) dexamethasone suppression testing reliably distinguishes non-cushingoid obesity from Cushing's syndrome.

To determine the sensitivity of the overnight 1-mg dexamethasone suppression test in diagnosing Cushing's syndrome, we evaluated the cortisol responses of 55 subjects (25 non-obese individuals with body mass index less than 25 kg/m2, 20 obese individuals with body mass index greater than 30 kg/m2, and 10 patients with surgically proven Cushing's syndrome) following ingestion of 1 mg dexamethasone at midnight. The basal 8 AM plasma cortisol levels among non-obese and obese individuals and patients with Cushing's syndrome were 310 +/- 85, 377 +/- 91, and 813 +/- 270 nmol/L, respectively. Following 1 mg of dexamethasone, Cushing's syndrome patients showed minimal suppression of cortisol to 609 +/- 180 nmol/L (P = 0.79). Non-obese and obese individuals suppressed to 18.7 +/- 6.0 nmol/L (P less than 0.001) and 22 +/- 7.1 nmol/L (P = 0.003), respectively. The results demonstrated similar cortisol responses to overnight dexamethasone suppression in obese and non-obese groups, and clearly distinguished these subjects from those with Cushing's syndrome. Obesity is not a confounding factor in the 1-mg dexamethasone suppression test.

Adult↗
PubMed1991

Sudden unexplained death syndrome--a new manifestation in melioidosis?

The indirect haemagglutination (IHA) test using sensitized turkey erythrocytes and the indirect immunofluorescence assay (IgM-IFA) was confirmed to be sensitive in the detection of a recent or current Pseudomonas pseudomallei infection in 19 culture-confirmed Singapore melioidosis patients. All were found to have antibody titres from 4 to 32768 in the IHA test and 10 to 320 in the IgM-IFA test. When these tests were employed on sera from 16 immigrant Thai construction workers who died of sudden unexplained death syndrome (SUDS) and 73 healthy Thai fellow workers, 93.8% and 68.8% of SUDS cases had IHA titre of greater than or equal to 4 and IgM-IFA titre of greater than or equal to 10 respectively, in contrast to 39.7% and 12.3% found among healthy Thai workers. These data indicate that at the time of death, most of the SUDS patients had an active infection with P. pseudomallei, possibly resulting from reactivation of a latent infection. The aetiological role of P. pseudomallei as the major cause of SUDS is discussed.

Adult↗
PubMed1991

Evaluation of biodegradable ampicillin anhydrate microcapsules for local treatment of experimental staphylococcal osteomyelitis.

Successful treatment of chronic osteomyelitis requires sustained high concentrations of antibiotics locally within the infected bone. The efficacy of biodegradable (poly-DL-lactide-co-glycolide) microspheres containing 30.7% ampicillin anhydrate for the local treatment of experimental staphylococcal osteomyelitis was evaluated in rabbits. In the initial experiment, antibiotic therapy was initiated immediately following injection of Staphylococcus aureus into the proximal tibial metaphysis. A single intramedullary injection of microencapsulated ampicillin (100 mg) prevented osteomyelitis in all seven animals tested and was as effective as a two-week course of parenteral ampicillin administration. When antibiotic therapy was delayed for seven days, osteomyelitis developed in four of eight animals treated locally with microencapsulated ampicillin and in six of eight animals that received parenteral ampicillin therapy. When antibiotic therapy was delayed for seven days and was preceded by debridement, all ten animals treated locally with microencapsulated ampicillin had sterile bone cultures. In contrast, seven of ten animals treated locally with unencapsulated ampicillin powder developed osteomyelitis. Biodegradable antibiotic-loaded microspheres may be of clinical benefit for the local treatment of chronic osteomyelitis.

Ampicillin↗