Search PubMed⌕ Search

Biomedical subjects

J Love

Publications and source records attributed to J Love.

At least 55 records · Page 3Linked to original sources
PubMed1995

Relation of haemostatic, fibrinolytic, and rheological variables to the angiographic extent of peripheral arterial occlusive disease.

We investigated the relationships between the angiographic severity of peripheral arterial occlusive disease (PAOD) and haemostasis, fibrinolytic, and rheological variables in 219 patients with symptomatic peripheral arterial occlusive disease (PAOD). White cell count, fibrinogen, cross-linked fibrin degradation products (FDP), von Willebrand factor, and plasminogen activator inhibitor levels were all elevated in comparison with age-matched population controls (all p < 0.0001, Mann-Whitney U test), while fibrinogen (Spearman r = 0.30), von Willebrand factor (r = 0.40), and log (FDP) (r = 0.56), (all p < 0.0001) showed a strong correlation with the angiographic extent of PAOD. Multivariate analysis indicated that log (FDP) was a strong independent predictor of the angiographic severity of PAOD (p < 0.0001), in addition to increasing age (p < 0.0001), presence of tissue sepsis (p < 0.02), prior vascular surgery (p = 0.007), and other vascular pathology (p = 0.007). These results confirm that increase in fibrinogen, von Willebrand factor, plasminogen activator inhibitor and fibrin turnover, are strongly associated with the presence of symptomatic peripheral arterial disease, and suggest that there may be a causal link between fibrin turnover, as determined by FDP levels, and the extent of peripheral arterial occlusive disease.

Adult↗
PubMed1995

Relation of haemostatic, fibrinolytic, and rheological variables to the angiographic extent of peripheral arterial occlusive disease.

We investigated the relationships between the angiographic severity of peripheral arterial occlusive disease (PAOD) and haemostasis, fibrinolytic, and rheological variables in 219 patients with symptomatic peripheral arterial occlusive disease (PAOD). White cell count, fibrinogen, cross-linked fibrin degradation products (FDP), von Willebrand factor, and plasminogen activator inhibitor levels were all elevated in comparison with age-matched population controls (all p < 0.0001, Mann-Whitney U test), while fibrinogen (Spearman r = 0.30), von Willebrand factor (r = 0.40), and log (FDP) (r = 0.56), (all p < 0.0001) showed a strong correlation with the angiographic extent of PAOD. Multivariate analysis indicated that log (FDP) was a strong independent predictor of the angiographic severity of PAOD (p < 0.0001), in addition to increasing age (p < 0.0001), presence of tissue sepsis (p < 0.02), prior vascular surgery (p = 0.007), and other vascular pathology (p = 0.007). These results confirm that increases in fibrinogen, von Willebrand factor, plasminogen activator inhibitor and fibrin turnover, are strongly associated with the presence of symptomatic peripheral arterial disease, and suggest that there may be causal link between fibrin turnover, as determined by FDP levels, and the extent of peripheral arterial occlusive disease.

Age Factors↗
PubMed1994

Serological and nucleic acid analyses for HIV and HTLV infection on archival human plasma samples from Zaire.

In order to better understand the genomic diversity and molecular phylogeny of the human retroviruses, the plasmas from 250 Zairean patients collected in 1969 were tested for antibodies to human T-cell lymphoma and human immunodeficiency viruses (HTLV or HIV) using ELISA and confirmatory Western blots and for viral nucleic acids by reverse transcriptase-directed PCR (RT-PCR). Interestingly, none of the patients was confirmed positive for HIV, even though this region is now endemic for HIV-1. However, 74 (30%) and 3 (1%) of the samples were positive for antibodies to HTLV-I and II, respectively. Forty-four of 74 (59%) Western blot-positive Zairean samples were RT-PCR positive for HTLV-I, while 1 of 3 (33%) of HTLV-II-seropositive samples was RT-PCR positive. On the contrary, none of the Western blot-negative or indeterminate samples were RT-PCR positive for either HTLV-I or HTLV-II. We have cloned and sequenced 140 bp of the pol gene flanked by SK110/SK111 from 8 HTLV-I- and 1 HTLV-II-positive archival samples from Zaire. The HTLV-I isolates from Zaire cluster together as a phylogenetic group, diverging from the prototype Japanese HTLV-I (ATK) by a range of 1.4 to 3.6%. Their close homology to some African STLV-I isolates suggests relatively recent interspecies transmission. The Zairean HTLV-II isolate is closely grouped with the HTLV-II substrain of isolates found in Paleo-Amerindians of the New World, making it unlikely that it represents an endemic African strain.

Antibodies, Viral↗
PubMed1994

Transgenic birds by DNA microinjection.

We have developed a method for production of transgenic chickens by DNA microinjection of chick zygotes followed by ex vivo embryo culture. The fate of plasmid DNA microinjected into the germinal disc of zygotes was analyzed in embryos which survived for at least 12 days in culture. Approximately half of the embryos contained plasmid DNA, 6% at a level equivalent to one copy per cell in all tissues analyzed. Seven chicks, 5.5% of the total number of injected ova, survived to sexual maturity. One of these, a cockerel, transmitted the exogenous DNA to 3.4% of his offspring. These G1 birds have reached sexual maturity and have been bred to produce transgenic offspring, demonstrating that stable transmission of foreign DNA can be obtained by our method.

Animals↗
PubMed1994

Management of common bile duct stricture caused by chronic pancreatitis with metal mesh self expandable stents.

Twenty patients with chronic pancreatitis and signs of biliary obstruction were treated by endoscopic placement of self expandable metal mesh stents, and followed up prospectively. Eleven had been treated previously with plastic endoprostheses. All had persistent cholestasis, seven patients had jaundice, and three overt cholangitis. Endoscopic stent placement was successful in all cases. No early clinical complication was seen and cholestasis, jaundice or cholangitis rapidly resolved in all patients. Mean follow up was 33 months (range 24 to 42) and consisted of clinical evaluation, ultrasonography, and endoscopic retrograde cholangiopancreatography (ERCP). In 18 patients, successive ERCPs and cholangioscopies have shown that the metal mesh initially embeds in the bile duct wall and is rapidly covered by a continuous tissue by three months. The stent lumen remained patent and functional throughout the follow up period except in two patients who developed epithelial hyperplasia within the stent resulting in recurrent biliary obstruction, three and six months after placement. They were treated endoscopically with standard plastic stents with one of these patients ultimately requiring surgical drainage. No patient free of clinical or radiological signs of epithelial hyperplasia after six months developed obstruction later. This new treatment could become an effective alternative to surgical biliary diversion if further controlled follow up studies confirm the initial impression that self expandable metal mesh stents offer a low morbidity alternative for longterm biliary drainage in chronic pancreatitis without the inconvenience associated with plastic stents.

Adult↗
PubMed1994

Procalcitonin increase after endotoxin injection in normal subjects.

As procalcitonin concentrations have been shown to be elevated in patients with septicemia and gram-negative infections in particular, we proceeded to investigate the effect of endotoxin, a product of gram-negative bacteria, on procalcitonin concentrations in normal human volunteers. Endotoxin from Escherichia coli 0113:H10:k, was injected i.v. at a dose of 4 mg/kg BW into these healthy volunteers. Blood samples were obtained before and 1, 2, 4, 6, 8, and 24 h after injection of the endotoxin. Each patient's cardiovascular and overall clinical status was monitored over this period. The patients developed chills and rigors, myalgia, and fever between 1-3 h. Tumor necrosis factor-alpha levels increased sharply at 1 h and peaked at 90 min, reaching the baseline concentration thereafter by 6 h. Interleukin-6 levels increased more gradually, peaking at 3 h and reaching the baseline concentration at 8 h. The procalcitonin concentration, which was undetectable (< 10 pg/mL) at 0, 1, and 2 h, was detectable at 4 h and peaked at 6 h, maintaining a plateau through 8 and 24 h (4 ng/mL). There was no elevation of calcitonin concentrations, which remained below 10 pg/mL, the lowest sensitivity of the assay. Procalcitonin was measured by a two-antibody immunoradiometric assay specific for this peptide, with no cross-reactivity with calcitonin, katacalcin, or calcitonin gene-related peptide. We conclude that endotoxin induces the release of procalcitonin systemically, that this increase is not associated with an increase in calcitonin, and that the increase in procalcitonin associated with septicemia in patients may be mediated through the effect of endotoxin described here. Whether procalcitonin participates in the mechanisms underlying inflammation remains to be investigated.

Adult↗
PubMed1994

Feeding an isocaloric omega-3 fatty acid diet reduces the brush border membrane vesicle uptake of glucose in streptozotocin-diabetic rats.

Glucose uptake is increased into the intestine of diabetic rats, and this adaptation can be modified further by manipulation of the type of fatty acids in the triglycerides in the diet. Jejunal brush border membrane vesicles were used to examine the uptake of D-glucose into the jejunum of non-diabetic control and streptozotocin-diabetic rats fed for two weeks in isocaloric semisynthetic diet enriched with saturated fat (beef tallow) or polyunsaturated omega-3 fatty acids (fish oil). The time-course of uptake of 100 microM glucose demonstrated an overshoot which peaked at approximately 30 seconds and declined thereafter to an equilibrium plateau. In concentration studies, glucose uptake was greater into brush border membrane vesicles of diabetic as compared with control rats. The maximal transport rate (Vmax) was increased approximately 9-fold in diabetics as compared with control rats fed beef tallow (p < 0.05), and was increased approximately 6-fold in diabetic rats fed fish oil. In diabetic rats, feeding fish oil reduced the value of the Vmax by approximately 50% as compared with diabetic rats fed beef tallow. Thus, the enhanced glucose uptake into BBM vesicles of streptozotocin-diabetic rats can be partially corrected by feeding an isocaloric semisynthetic diet enriched with polyunsaturated omega-3 fish oils.

Animals↗
PubMed1994

Comparisons between Hologic, Lunar and Norland dual-energy X-ray absorptiometers and other techniques used for whole-body soft tissue measurements.

OBJECTIVES: Assessment of the precision and accuracy of dual-energy X-ray absorptiometers (DXA) from three manufacturers, used for measuring soft-tissue composition, and comparability with each other and other techniques. DESIGN: Measurements of an anthropomorphic model of variable composition and thickness. 11 volunteers measured with each instrument and by underwater weighing (UWW) and three brands of bioelectric impedance analysis (BIA) apparatus. RESULTS: New software, introduced by each manufacturer during the course of the investigation, led to changes in measured fat proportion. The precision of determination of fat proportion by DXA in the (small) model was 3-4% (coefficient of variation), with little difference between brands. In vivo precision was 2-3%. In the model, measurements of % fat differed from the nominal values, but variation with thickness was small. There were significant mean differences of total fat proportion in the volunteers between pairs of DXA instruments of 2.6-6.3% fat. The SDs of the differences were 1.8-2.9% fat. Regional differences were greater, with trunk % fat being particularly underestimated by Hologic relative to Lunar and Norland. Compared with UWW, mean % fat was the same for Hologic, but higher for Lunar and Norland. SDs of 4% demonstrated inadequate agreement. The differences varied with proportion of bone in lean tissue, questioning the assumption of constant density of lean tissue in UWW. There were no mean differences of % fat between the BIA instruments and DXA and UWW, but SDs of 3-6% suggest that BIA using these instruments does not offer an acceptable accuracy in estimating fat proportion. CONCLUSIONS: UWW has limitations as a reference method. DXA is a useful technique, but its limitations, particularly regarding assumptions about fat distribution, must be borne in mind. The differences of fat proportion recorded by the three DXA instruments are such as to preclude interchangeability in measurements of individual subjects or in clinical trials.

Absorptiometry, Photon↗
PubMed1993

Multiple spontaneous coronary artery dissections in a middle aged woman: support for an underlying eosinophilic arteritis predisposing to intimal disruption.

A 43-year-old female received tissue plasminogen activator for an acute antero-apical myocardial infarction. Cardiac catheterization demonstrated three focal dissections involving the left anterior descending and circumflex arteries. She expired unexpectantly after undergoing emergency coronary artery bypass grafting for therapy of an extension of her infarct. To our knowledge, this is the fourth report of multiple spontaneous coronary artery dissections and the second in which tissue plasminogen activator was administered. The histologic findings and their implications are reviewed.

Adult↗
PubMed1993

A prospective comparative study of continuous arteriovenous hemodiafiltration and continuous venovenous hemodiafiltration in critically ill patients.

We have prospectively studied and compared two consecutive groups of critically ill patients treated with either continuous arteriovenous hemodiafiltration (CAVHD) (n = 28) or continuous venovenous hemodiafiltration (CVVHD) (n = 25) to establish the technique of choice. The two groups were comparable in mean age (59 v 58 years), mean Acute Physiology and Chronic Health Evaluation (APACHE) II score (29.6 v 27.4, P = NS), requirements for inotropic drugs, and mean number of failing organs (2.9 v 3.2). CVVHD led to a greater amount of hourly ultrafiltrate (mean, 590 v 424 mL; P < 0.001), but urea and creatinine clearances were not significantly different with the two techniques. Twelve patients survived in the CAVHD group (42.8%) and 13 in the CVVHD group (52%; P = NS). The major advantage for CVVHD use was the substantial decrease in the number of access-related complications (2 v 10; P < 0.025). We conclude that while CVVHD does not offer a significant increase in solute clearance, it significantly minimizes vascular access-related morbidity and should therefore be regarded as the therapeutic modality of choice.

Chi-Square Distribution↗
PubMed1993

Genetic heterogeneity in human T-cell leukemia/lymphoma virus type II.

DNA from the peripheral blood mononuclear cells of 17 different individuals infected with human T-cell lymphoma/leukemia virus type II (HTLV-II) was successfully amplified by the polymerase chain reaction (PCR) with the primer pair SK110/SK111. This primer pair is conserved among the pol genes of all primate T-cell lymphoma viruses (PTLV) and flanks a 140-bp fragment of DNA which, when used in comparative analyses, reflects the relative degree of diversity among PTLV genomes. Cloning, sequencing, and phylogenetic comparisons of these amplified 140-bp pol fragments indicated that there are at least two distinct genetic substrains of HTLV-II in the Western Hemisphere. These data were confirmed for selected isolates by performing PCR, cloning, and sequencing with to 10 additional primer pair-probe sets specific for different regions throughout the PTLV genome. HTLV-II isolates from Seminole, Guaymi, and Tobas Indians belong in the new substrain of HTLV-II, while the prototype MoT isolate defines the original substrain. There was greater diversity among HTLV-II New World strains than among HTLV-I New World strains. In fact, the heterogeneity among HTLV-II strains from the Western Hemisphere was similar to that observed in HTLV-I and simian T-cell lymphoma/leukemia virus type I isolates from around the world, including Japan, Africa, and Papua New Guinea. Given these geographic and anthropological considerations and assuming similar mutation rates and selective forces among the PTLV, these data suggest either that HTLV-II has existed for a long time in the indigenous Amerindian population or that HTLV-II isolates introduced into the New World were more heterogeneous than the HTLV-I strains introduced into the New World.

Amino Acid Sequence↗
PubMed1992

Use of chromosomal gene fusions to investigate the role of repetitive DNA in regulation of genes involved in lipopolysaccharide biosynthesis in Haemophilus influenzae.

The lic3 locus of Haemophilus influenzae consists of four open reading frames. The derived amino acid sequences of orf2 and orf4 exhibit homology to Escherichia coli GalE and AdK, respectively. The functions of orf1 and orf3 remain unknown. orf1 contains multiple tandem repeats of the tetrameric DNA sequence CAAT near the 5' end. Two possible translational starts (ATG1 and ATG2) lie upstream. We have used lacZ fusions to investigate whether changes in the number of CAAT repeats in conjunction with differential usage of the upstream frames control the expression of lic3-orf1. Phase-variable expression of lacZ was observed for individual colonies and could be related to variable numbers of CAAT repeats. Of the three possible upstream frames, only one, containing the more downstream of the two possible ATG start codons (ATG2), is used for strong expression of lacZ. Utilization of the more upstream ATG (ATG1) or ATG2 was observed with medium-level expression, while utilization of any of the three possible frames was observed when lacZ was expressed at low to undetectable levels, indicating that other mechanisms may affect expression. To investigate this, lacZ was fused in frame with ATG2 of lic3-orf1, with concomitant deletion of the repeats. Phase-variable expression was still observed, supporting the view that an alternative level of control operates in conjunction with the repeat mechanism.

Amino Acid Sequence↗
PubMed1992

Use of continuous haemodiafiltration: an approach to the management of acute renal failure in the critically ill.

We have prospectively investigated the effect of a flexible approach to the management of acute renal failure in critically ill patients based on continuous haemodiafiltration (CHD). Fifty critically ill patients (mean APACHE II score 28.1, range 18-37), with a mean age of 59.5 years, were treated with continuous arteriovenous haemodiafiltration (CAVHD) and/or continuous venovenous haemodiafiltration (CVVHD). CHD achieved excellent haemodynamic stability and control of azotaemia in all patients and permitted aggressive parenteral nutrition. The mean blood urea concentration fell from 33.9 mmol/l (95% confidence interval, CI, 29.1-38.7) to a plateau of 17 mmol/l (95% CI 14.3-19.7) after 72 h of therapy despite persistent anuria and the parenteral administration of 0.3 g/kday of protein nitrogen (mean urea clearance: 24.2 ml/min; 95% CI 22.9-25.5). No supplemental dialytic therapy was required during the 9,485 h of treatment. All clinically significant complications related to vascular access (14%). Twenty-two patients (44%) survived to be discharged from the ICU. CHD is relatively safe and effective in the management of acute renal failure in the critically ill.

Acute Kidney Injury↗
PubMed1992

Management of acute renal failure in the critically ill with continuous venovenous hemodiafiltration.

Continuous venovenous hemodiafiltration (CVVHD) has been increasingly utilized for renal replacement therapy in the critically ill. We report details of a prospective study of CVVHD in 12 critically ill patients (7 males, 5 females; mean age 60 years, range 30-72 years; Apache II score mean 27.4, range 21-35) with oligoanuric acute renal failure supported on CVVHD. Vascular access was obtained via double lumen subclavian or femoral cannulae. The mean pretreatment urea was 35.9 mM/L and the mean pretreatment creatinine was 559 microM/L. After 24 h of treatment on CVVHD these fell to a urea mean of 20.3 mM/L and a creatinine mean of 298 microM/L and remained stable at these values for the duration of CVVHD. The mean net ultrafiltrate volume was 551 mL/h, with a urea clearance mean of 26.6 mL/min and a creatinine clearance mean of 23.7 mL/min. There were no complications related to use of the blood pump module or extracorporeal circuit. Excellent hemodynamic stability, control of fluid and electrolyte balance, and azotaemia control were maintained while on CVVHD. Technique survival was 100%. Patient survival was 42%. We conclude that CVVHD is a safe, effective, and durable therapy for the treatment of acute renal failure in the critically ill and that it offers outstanding metabolic control and cardiovascular stability.

Acute Kidney Injury↗
PubMed1992

Prosthetic replacement of the superior vena cava with a custom-made pericardial graft: an experimental study.

Prosthetic replacement of the vena cava has been disappointing, mainly because of the hemodynamic characteristics of the venous system and the physical properties of the prostheses used. Spiral grafts constructed with autogenous saphenous vein have been the most successful prostheses to date, but their use is limited to replacement of short segments, and intraoperative construction is time consuming. The authors report their experience with a graft constructed of extra-thick bovine pericardium (PX) and surgical staples. Externally stented polytetrafluoroethylene (PTFE) was used as a control. The superior vena cava was replaced in 13 ewes; PTFE was used in 6 (group 1) and PX in 7 (group 2). Mean follow-up was 15 +/- 8 months for group 1 and 13 +/- 8 for group 2. Cumulative graft follow-up totalled 4612 graft-days. There was one graft occlusion in each group. Patency rates (80%) were similar for the two groups. Histologic changes in pericardial grafts were more marked but did not influence patency. This study reports the longest experimental follow-up (maximum 23 months) and graft patency to date for replacement of the superior vena cava. Both types of graft performed excellently.

Animals↗
PubMed1991

Continuous arteriovenous haemodiafiltration in the critically ill: influence on major nutrient balances.

The impact of continuous arteriovenous haemodiafiltration (CAVHD) on nitrogen, lipid and carbohydrate balance was studied in 9 parenterally fed critically ill patients with acute renal failure. The effects on carbohydrate delivery of varying dialysate glucose concentrations or flow rates were also investigated. The total daily nitrogen loss was a mean of 24.1 g (95% CI 20.9-27.3 g/24 h) with non-urea nitrogen losses of 7.6 g (95% CI 5.6-9.6 g/24 h). Glucose delivery was a mean 5.8 g/h with a dialysate glucose concentration of 1.5% and a flow rate of 1 l/h (95% CI 4.5-7.0 g/h). Carbohydrate delivery increased with increased dialysate glucose concentration (mean 11.4 g/h with 2.5% glucose: 95% CI 9.6-13.1 g/h; mean 14.9 g/h with a 4.25% concentration: 95% CI 10.9-19; and with increased dialysate flow rates (mean 9.6 g/h, 95% CI 6.8-12.4 g/h, using 2 l/h of 1.5% glucose). Only trace amounts of cholesterol and/or triglycerides were detected in occasional ultradiafiltrate samples. CAVHD has an important impact on nitrogen and carbohydrate balance, but not on lipid status. Knowledge of these interactions is crucial for the rational planning of nutritional strategies in the critically ill.

Acute Kidney Injury↗
PubMed1991

Gene rearrangements in the diagnosis of lymphoma/leukemia. Guidelines for use based on a multiinstitutional study.

The demonstration of immunoglobulin or T-cell receptor gene rearrangements in human lymphoproliferative processes with the use of DNA hybridization has gained great popularity as a sensitive laboratory adjunct to diagnostic hematopathology. The fact that nearly all B- or T-cell malignant lymphomas and leukemias have one or more rearranged antigen receptor genes provides a biologic basis for a diagnostic test. To formally analyze the sensitivity, specificity, and reproducibility of gene rearrangements in the diagnosis of human lymphoproliferative disease, the authors conducted a large, multiinstitutional study. Through a blinded, controlled approach, gene rearrangement analysis of 275 cases was shown to carry a high correlation with conventional phenotyping and histologic diagnosis, with only minor false-positive and false-negative rates. Significantly, no rearrangements were detected in normal lymphoid tissues or carcinomas, sarcomas, or melanomas. In a randomized study of 50 cases, laboratory results showed a high rate of interlaboratory agreement, regardless of the level of previous experience. Furthermore, the reproducibility of interpretation of data (Southern blot autoradiograms) of 192 cases showed high concordance among 11 observers from multiple laboratories. Based on these findings, the authors propose a set of guidelines for interpretation of gene rearrangement analysis that, if carefully followed, renders this a highly reproducible, safe, and accurate addition to the diagnostic regimen for human lymphoproliferative processes.

B-Lymphocytes↗