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Biomedical subjects

L Harper

Publications and source records attributed to L Harper.

At least 55 records · Page 3Linked to original sources

Surgery in Belgium.

To fully understand the present state of surgery in Belgium, it is necessary to know the structure of the Belgian State, the type of education, the statutory health insurance system, and the professional bodies representing surgeons. One of the most important problems is the excessive number of physicians, which recently led to the establishment of limits on the number of candidates receiving medical certification. Surgical training modalities are described and the results of a retrospective study concerning the quality of training are detailed. The continuing medical education and peer-review system (accreditation) is presented.

Accreditation↗

A variant of variola virus, characterized by changes in polypeptide and endonuclease profiles.

A variant of variola virus is described which produces a late polypeptide of 25 kDa instead of one of 27 kDa and which has an additional endonuclease cleavage site for SalI in the viral DNA. These markers were shown to be genetically independent and to characterize 14 of the 48 variola strains which were examined. The variant strains were isolated from smallpox outbreaks originating in or from Pakistan between 1961 and 1974 and also from two cases at a Mission Hospital in Vellore, India in 1964. No variant strains were found among 9 other isolates from cases of variola major occurring in other parts of India or in Bangladesh, nor among 4 isolates from Indonesia, 15 from Africa or 6 isolates of variola minor.

Animals↗

Ectopic expression of the maize homeobox gene liguleless3 alters cell fates in the leaf.

The semidominant mutation Liguleless3-O (Lg3-O) causes a blade-to-sheath transformation at the midrib region of the maize (Zea mays L.) leaf. We isolated a full-length lg3 cDNA containing a knotted1-like family homeobox. Six Lg3-O partial revertant alleles caused by insertion of a Mutator (Mu) transposon and two deletion derivatives were isolated and used to verify that our knotted1-like cDNA corresponds to the LG3 message. In wild-type plants the LG3 mRNA is expressed in apical regions but is not expressed in leaves. In mutant plants harboring any of three dominant lg3 alleles (Lg3-O, -Mlg, and -347), LG3 mRNA is expressed in leaf sheath tissue, indicating that the Lg3 phenotype is due to ectopic expression of the gene. The Lg3-O revertant alleles represent two classes of Lg3 phenotypes that correlate well with the level of ectopic Lg3 expression. High levels of ectopic LG3 mRNA expression results in a severe Lg3 phenotype, whereas weak ectopic Lg3 expression results in a mild Lg3 phenotype. We propose that ectopic Lg3 expression early in leaf development causes the blade-to-sheath transformation, but the level of expression determines the extent of the transformation.

Alleles↗

Anterior flap for coverage following hip disarticulation for osteomyelitis.

The use of a posterior myocutaneous flap is the most common method of coverage following hip disarticulation. Other options for coverage following hemipelvectomy have been described mainly when the conventional flap is unavailable owing to tumor involvement. We report a case of hip disarticulation for a decubitus ulcer with underlying osteomyelitis of the proximal femur; coverage was obtained using an anterior myocutaneous flap. In this case, two previous unsuccessful attempts at wound coverage prior to the hip disarticulation using a lateral and a posterior flap made the anterior flap the best available option for closure. Complete healing was achieved within two months.

Diabetes Mellitus, Type 1↗

Mechanisms of endothelial injury in systemic vasculitis.

The precise etiology of primary systemic vasculitis remains unknown. However, recent advances in the understanding of the role of and interaction between the vascular endothelium, mediators, and immune effector cells have helped to further elucidate those specific processes that result in endothelial cell damage. In WG and MPA, the evidence favors an autoimmune inflammatory response characterized by specific mediators in which the endothelium is both target and active participant.

Animals↗

Low-density lipoprotein subfraction profiles in chronic renal failure.

BACKGROUND: Small low-density lipoprotein (LDL) particle size, a newly recognized risk factor for cardiovascular disease in the general population, is frequently associated with hypertriglyceridaemia, the predominant plasma lipid abnormality present in uraemia. METHODS: Plasma lipids and LDL subfraction profiles were examined in 33 non-dialysed patients with chronic renal failure (predial), 40 patients on continuous ambulatory peritoneal dialysis (CAPD), 42 haemodialysis patients (HD), 47 renal transplant recipients (RTR), and 44 controls. LDL subfractions separated by gel electrophoresis were scored by densitometric analysis (higher scores indicate profiles comprising smaller particles). RESULTS: All groups with renal failure had significantly elevated (mean+/-SD) LDL scores (predial 1.36+/-0.6, CAPD 1.71+/-0.9, HD 1.68+/-0.9, RTR 1.92+0.8 vs control 0.87+0.4, all P<0.001), this being the only lipid abnormality detected in the predialysis patients. In CAPD and HD patients, LDL scores were associated with serum triglyceride (r=0.81, P<0.001 and r=0.70, P<0.001 respectively), cholesterol (r=0.55, P<0.001 and r=0.49, P<0.01) and HDL-cholesterol (r= -0.43, P<0.01 and r= -0.51, P<0.01), whilst no such relationship was seen in the predialysis and RTR groups, suggesting that other factors were important. CONCLUSIONS: The presence of small LDL particles appears to be an early and unexplained feature of the uraemic dyslipidaemia. This abnormality persists after renal transplantation and may represent an important atherogenic risk factor.

Adrenergic beta-Antagonists↗

Health problems of corporate travelers: risk factors and management.

BACKGROUND: Numerous studies have been done regarding health problems experienced by tourists in developing countries; however, little data exist about these health risks and illnesses experienced by corporate travelers. METHODS: The authors examined by electronic survey the health risks encountered, compliance with pretravel health recommendations, and illnesses and injuries experienced by employees of the Coca-Cola Company who travel internationally. RESULTS: Two hundred twenty-six travelers responded. Although most travelers ate meals at their hotels and chose foods that were cooked and still hot, over half also ate foods that remained at room temperature for prolonged periods and/or ate from cold salad bars. Almost half drank untreated tap water. Thirty-five percent of travelers developed diarrhea and 29% reported respiratory illnesses, with 12% seeking medical attention for their problems. Forty-three percent of those traveling to malarious regions admitted to noncompliance with antimalarial recommendations. Health kits provided were used by only 51% of travelers. CONCLUSIONS: Although many corporate travelers followed pretravel health recommendations, some did not. Injuries, fever, and illnesses such as diarrhea and respiratory infections occurred. Strategies to improve access to the travel clinic and the acquisition of health information and travel health kits are being implemented. The health risks and behaviors of corporate travelers, including the potential impact of psychosocial stressors, need greater attention.

Acute Disease↗

Sparfloxacin vs ofloxacin in the treatment of acute bacterial exacerbations of chronic bronchitis: a multicenter, double-blind, randomized, comparative study. Sparfloxacin Multicenter ABECB Study Group.

STUDY OBJECTIVE: Comparison of efficacy and safety of sparfloxacin vs ofloxacin for treatment of acute bacterial exacerbations of chronic bronchitis (ABECB). DESIGN: Multicenter, double-blind, randomized study. SETTING: Sixty-eight private offices and outpatient clinics in the United States and Canada. PATIENTS: Seven hundred ninety-eight adults with ABECB, as confirmed by the acute onset of new (or worsened from the immediate premorbid state) cough and sputum production. INTERVENTIONS: Randomization 1:1 to sparfloxacin, 400 mg on day 1, then 200 mg once daily, or ofloxacin, 400 mg twice daily, with matching comparator placebos, given concurrently for 10 consecutive days. RESULTS: The primary efficacy parameter was overall response in the bacteriologically evaluable population. Overall success rates in this population were 85.3% and 89.3% for sparfloxacin and ofloxacin, respectively. The two-sided 95% confidence interval was -9.9, 1.9, indicating that sparfloxacin was statistically equivalent to ofloxacin. The all-treated population analysis was similar to that in the evaluable population. Bacterial eradication rates were similar in both treatment groups for Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, Chlamydia pneumoniae, Haemophilus parainfluenzae, Klebsiella pneumoniae, Enterobacter cloacae, and Staphylococcus aureus. The frequency of adverse events overall was comparable in the two treatment groups. The sparfloxacin group had a lower frequency of digestive and nervous system adverse events, but a higher frequency of photosensitivity reactions than the ofloxacin group. CONCLUSIONS: Once-daily oral treatment with 200 mg sparfloxacin (after initial 400 mg dose) is as effective as twice-daily treatment with 400 mg ofloxacin in patients with ABECB.

Acute Disease↗

Focal segmental necrotizing glomerulonephritis in rheumatoid arthritis.

We report ten patients with rheumatoid arthritis (RA) who developed a focal segmental necrotizing glomerulonephritis (FSNGN) and extracapillary proliferation typical of vasculitic glomerulonephritis. Five patients also had extrarenal vasculitis. Renal presentation was with renal impairment (n = 9) (median creatinine 726 mumol/l, range 230-1592 mumol/l), microscopic haematuria (n = 8) and proteinuria (n = 10). Nine patients were seropositive for rheumatoid factor and nine had bone erosions. Serum from four of five patients tested by indirect immunofluorescence was positive for antineutrophil cytoplasmic antibody (ANCA) with perinuclear staining. Only three patients had penicillamine or gold therapy. Treatment was with prednisolone and cyclophosphamide (six patients, two of whom were also plasma-exchanged), prednisolone and azathioprine (two patients) and prednisolone alone (two patients). There was a marked improvement in renal function in eight patients. Two patients with dialysis-dependent renal failure recovered renal function, although in one patient this was transient and she required further dialysis 4 months later. Two other patients progressed to dialysis at 3 months and 1 year respectively. Four patients died, one remains dialysis-dependent, and four continue to have good renal function at 5 year follow-up (median creatinine 148.5 mumol/l, range 120-193 mumol/l). One patient was lost to follow-up at 5 years. FSNGN should be considered in all patients with RA and renal impairment, proteinuria and/or microscopic haematuria. This diagnosis appears to be more likely in patients with clinical extrarenal vasculitis, bone erosions or who are seropositive. In these cases, an urgent renal biopsy is indicated.

Adult↗

L-homoarginine studies provide insight into the antimetabolic properties of L-canavanine.

A method for the chemical synthesis of L-homoarginine, based on the guanidination of L-lysine with O-methylisourea, has been developed; this procedure provides radiochemically pure L-[guanidino-14C]homoarginine in high yield. Radiolabeled homoarginine is incorporated readily into the newly synthesized hemolymphic proteins of larvae of the tobacco hornworm, Manduca sexta without adversely affecting larval growth and development. This finding stands in sharp contrast to the effect of L-canavanine, another L-arginine analog, which is markedly deleterious to these larvae. Homoarginine is incorporated into M. sexta lysozyme, and the antibacterial proteins of the fly, Phormia terranovae with impunity. In contrast, the comparable canavanine-containing enzymes are inhibited severely. Experimental evidence is presented that the innocuous nature of homoarginine results from the elevated pKa value of its guanidino group which arguably exceeds even that of arginine. As a result, homoarginine does not disrupt essential residue interactions. In contrast canavanine, which is much less basic than arginine, does adversely affect R group interactions forming the requisite three-dimensional conformation of the protein.

Animals↗