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Biomedical subjects

K A Neftel

Publications and source records attributed to K A Neftel.

At least 19 recordsLinked to original sources
PubMed2001

Hyperferritinemia as indicator for intravenous immunoglobulin treatment in reactive macrophage activation syndromes.

The underlying mechanisms of reactive macrophage activation syndromes (rMAS) are not understood in detail, and there is no specific treatment. This observational study was prompted by intravenous immunoglobulin (IVIG), dramatically halting two distinct rMAS episodes in the same patient. We evaluated the potential benefits of IVIG administration in treating fulminant rMAS and the usefulness of monitoring serum ferritin levels as an indication for emergency treatment with IVIG. Ten females and 10 males experiencing 22 episodes of rMAS were recruited on the basis of serum ferritin levels >or=10,000 microg/l and/or direct evidence of haemophagocytosis in 11 intensive care units in secondary and tertiary care hospitals in Switzerland between October 1993 and May 2000. In individual patients, serially measured ferritin was closely related to disease activity. Abrupt increases of up to >100,000 microg/l could be observed within hours. Rapid and profound beneficial effects of emergency IVIG treatment were seen in 12 episodes of rMAS accompanied by a prompt decrease of serum ferritin. IVIG produced partial or delayed improvements in 5 patients. No apparent effects were seen in 5 patients. IVIG was only successful if started early during the ferritin run-up to peak values. In conclusion, IVIG is effective in at least a subgroup of adult rMAS when started at the beginning of the macrophage activation process. The monitoring of serum ferritin levels might be helpful in detecting macrophage activation in order to commence IVIG treatment early enough.

Adolescent↗
PubMed2000

Elevation of soluble Fas and soluble Fas ligand in reactive macrophage activation syndromes.

Derailed T-cell activation can give rise to life-threatening macrophage activation, the final common pathway of the different forms of reactive macrophage activation syndromes (rMAS). Besides inappropriate activation of the immune system, impaired termination of immune responses might be another mechanism leading to rMAS. The Fas (CD95)/Fas ligand (CD95 ligand) system functions in turning off immune responses by executing activation-induced cell death (AICD). Soluble Fas (sFas) and Fas ligand (sFasL) can interfere with their corresponding membrane-bound counterparts, qualifying them as potential parameters of impaired immune termination. Hence, sFas and sFasL were analyzed in sera of rMAS patients. We show that soluble Fas/CD95 (sFas) is elevated >2 SD over the mean of controls in all 8 rMAS episodes studied (mean 12.08 +/- 6.12 ng/mL, range 3.7-20.2; controls 2.46 +/- 0.49, range 1.5-2.9). sFasL was detected during five rMAS episodes (0.70 +/- 0.49 ng/mL, range 0.16-1.28; controls all below the limit of detection of 0.1). In addition, both parameters decrease during convalescence, reflecting clinical evolution. In conclusion, sFas seems to be consistently elevated during acute rMAS. sFasL is detected only in a subgroup of our adult rMAS patients extending the recent finding of sFasL elevation in a majority of children with macrophage activation syndromes (Hasegawa et al. Blood 1998;91(8):2793-2799). By interfering with AICD, sFas and sFasL might contribute to the pathogenesis of at least a subset of rMAS.

Adult↗
PubMed2000

Grepafloxacin against penicillin-resistant pneumococci in the rabbit meningitis model.

Grepafloxacin, a new fluoroquinolone, produced bactericidal activity comparable to that of vancomycin and ceftriaxone in the treatment in rabbits of meningitis caused by a pneumococcal strain highly resistant to penicillin (MIC 4 mg/L) (triangle uplog(10) cfu/mL*h for grepafloxacin, -0.32 +/- 0.15; dose, 15 mg/kg iv; triangle uplog(10) cfu/mL*h for vancomycin, -0.39 +/- 0.18; dose, 2 x 20 mg/kg iv; triangle uplog(10) cfu/mL*h for ceftriaxone, -0.32 +/- 0. 12; dose, 125 mg/kg iv). Higher doses of grepafloxacin (30 mg/kg and 2 x 50 mg/kg) did not improve the killing rates. The combination of grepafloxacin with vancomycin was not significantly superior to monotherapies (P > 0.05). In vitro, grepafloxacin was bactericidal at concentrations above the MIC. Using concentrations around the MIC, addition of vancomycin to grepafloxacin showed synergic activity.

Animals↗
PubMed1999

Meropenem alone and in combination with vancomycin in experimental meningitis caused by a penicillin-resistant pneumococcal strain.

In a rabbit model of meningitis caused by a pneumococcus highly resistant to penicillin (MIC, 4 microg/ml), meropenem, a broad-spectrum carbapenem, was bactericidal (-0.48+/-0.14 deltalog10 cfu/ml h) and slightly superior to ceftriaxone (-0.34+/-0.23 deltalog10 cfu/ml x h) and vancomycin (-0.39+/-0.19 deltalog10 cfu/ml x h). Although the combination of vancomycin with ceftriaxone was significantly more active than ceftriaxone alone (-0.55+/-0.19 deltalog10 cfu/ml x h), only an insignificant gain was observed by the addition of vancomycin to meropenem (-0.55+/-0.28 deltalog10 cfu/ml x h).

Animals↗
PubMed1997

Signal generation in a non-EU country.

One of the most important objects of post-marketing surveillance is the early detection of serious, unknown and unexpected adverse events. As spontaneous reported adverse events vary considerably in their signal-generating value the Swiss Drug Monitoring Center SANZ implemented an early signal detection system in 1991. With a set of screening criteria the individual case reports are automatically checked by the system and read into a signal file. Subsequently these potential signals are processed to quantify the signal generating value of the particular case. According to the screening criteria 2072 (53%) of the reported cases were considered as potential signals. After validating and quantifying their signal value 27% (565) were drug-related and unlabelled, 8% (173) were also rated as serious. On the basis of these cases 114 labelling changes were made. Some of the most interesting cases are discussed. This computer-assisted early signal generation model in a small country with 7 million inhabitants has a high detectability of new, rare, serious and quality of life affecting adverse drug reactions (ADRs). These newly detected ADRs must be interpreted in cognizance of the limitations and restrictions of spontaneous reporting and do not allow pharmacoepidemiologic conclusions.

Journal Article↗
PubMed1995

[Frequency of antibiotics-associated colitis in hospitalized patients in 1974-1991 in "Comprehensive Hospital Drug Monitoring", Bern/St. Gallen].

In 3 divisions of internal medicine of teaching hospitals of the Comprehensive Hospital Drug Monitoring (CHDM) Foundation Bern/St Gallen, 42,920 patients consecutively admitted between 1974-1991 were investigated for adverse drug reactions. Of these 16,150 patients (38%) had received at least one systemically administered antibacterial drug during the hospital stay. Antibiotic-associated colitis included the following diagnoses: pseudomembranous colitis, hemorrhagic colitis and milder forms of colitis. We collected the data of these patients by searching for all diagnoses which might represent antibiotic-associated colitis (from the list of WHO adverse drug reaction terminology). 9 individual patients with one episode of probable antibiotic-associated colitis were found. In 5 of these cases, only one drug given during the hospital stay seemed to be implicated. An additional 32 patients were admitted with antibiotic-associated colitis in relation to treatment with the same groups of drugs before hospital admission. Based on the exposure pattern of the 9 patients with antibiotic-associated colitis compared to all patients exposed during hospital stay, we estimated the following frequencies related to the drug groups with at least 1,000 patients exposed: for all antibacterial chemotherapeutics 0.6/1000 (0.25-1.06); all penicillins 0.6/1000 (0.22-1.32), for benzyl-, phenoxy-, ureido-, isoxazolyl penicillins and methicillin 2.0/1000 (0.42-5.92) and aminopenicillin or analogues, with or without clavulanic acid 0.6/1000 (0.18-1.35). For cephalosporins the frequency is 1.4/1000 (0.17-5.12). Under sulfonamides combined with trimethoprim or related substances (5077 exposed patients) and fluoroquinolones (1043 exposed patients) no case was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Livedo reticularis and multiple vascular occlusions in a patient with HLA-B27-negative spondyloarthrosis and antiphospholipid antibodies].

We report the case of a 74-year-old patient with HLA-B27 negative spondylarthropathy presenting with acute disseminated vascular occlusions. The presence of livedo reticularis prompted a search for antiphospholipid antibodies which were found to be markedly elevated. Histopathological examination revealed noninflammatory vascular obstruction. The clinical evolution was rapidly fatal in spite of corticosteroid treatment. Livedo reticularis can be an important diagnostic clue to various types of underlying disease. Increased levels of antiphospholipid antibodies have been associated with thrombosis and thromboembolism, especially in the context of autoimmune diseases such as systemic lupus erythematosus. This paper reports antiphospholipid antibody-associated noninflammatory vascular occlusions in a patient with HLA-B27 negative spondylarthropathy. The pathogenetic mechanism of antiphospholipid antibody-mediated vascular occlusions is not completely understood and optimal therapy remains to be defined.

Aged↗
PubMed1991

[Evaluation of hematologic side effects of anti-infective therapy: agranulocytosis caused by beta-lactam antibiotics, vancomycin and amodiaquine].

Side effects in general and in particular to antiinfective therapy are obviously hardly predictable and a causal relationship is seldom firmly established. The handling of untoward reactions may be improved if a subpopulation which can be identified is at particular risk for a given reaction. A clear assessment of dose and time dependency of untoward reactions is important in this context. Agranulocytosis seen with (i) beta-Lactam-antibiotics, (ii) vancomycin and (iii) amodiaquine can exemplify how simultaneous investigations of epidemiological and experimental aspects lead to identification of a subpopulation at risk.

Agranulocytosis↗
PubMed1990

Fulminant group A streptococcal infections. Report of two cases.

We describe two female patients presenting with spontaneous peritonitis and fulminant Streptococcus pyogenes (Strep. pyogenes) septicemia and shock. Both patients recovered completely upon immediate antibiotic therapy, initially with broad range combination therapy effective against Strep. pyogenes, which was switched to penicillin G when culture results became available. This isolated strain in case 1 was M-type 28, which is the M-type most often isolated from vaginal swabs (as commensal) and from blood from patients with puerperal sepsis. Patient 1 had signs and symptoms of a toxic shock-like syndrome, including rapid onset of fever and shock, skin rash, desquamation of palms and soles, and multisystem involvement with vomiting, diarrhea, myalgia, renal failure, and severe disorientation without focal neurological deficits.

Anti-Bacterial Agents↗
PubMed1990

Simultaneous primary infection with HIV and CMV leading to severe pancytopenia, hepatitis, nephritis, perimyocarditis, myositis, and alopecia totalis.

Simultaneous primary infection with HIV and CMV in an 18-year-old woman led to an acute cytotoxic reaction, manifesting as pancytopenia, hepatitis, nephritis, perimyocarditis, and myositis. Within 14 days parameters indicating acute cell damage reverted to normal. Two weeks later transient alopecia totalis developed. Initially, HIV-antigen but no HIV antibodies were present. Within 3 weeks HIV-IgG antibodies appeared while HIV antigen disappeared. Anti-CMV-IgM was clearly and anti-CMV-IgG questionably positive; IgM persisted further, while IgG remained definitely undetectable. We speculate that a particular HIV-induced imbalance of the immune system led to a generalized severe cytotoxic reaction to a simultaneous infection with CMV.

Adolescent↗
PubMed1990

Heat induced radial segmentation of leukocyte nuclei in patients with polymyalgia rheumatica and other inflammatory diseases.

Heat induced radial segmentation of leukocyte nuclei is an in vitro phenomenon accompanying inflammatory diseases. We studied 62 patients with suspected polymyalgia rheumatica (PMR) to determine, whether heat induced radial segmentation can help in discriminating PMR from other conditions. At the initial presentation patients with PMR had more radial segmentation formation than patients with other inflammatory conditions. Prednisone induced a rapid and marked decrease in radial segmentation formation in patients with PMR. This latter finding was much less marked in patients with other inflammatory conditions. We conclude that heat induced radial segmentation at the initial presentation and during prednisone treatment can help in discriminating PMR from other inflammatory conditions.

Adrenal Cortex Hormones↗
PubMed1988

[Frequent problems of non-steroidal antirheumatic agents in old age].

The relationship between nonsteroidal antiinflammatory drugs (NSAID) and peptic lesions in the upper gastrointestinal tract remains unclear in many respects. Nevertheless, there is increasing evidence that the risk in patients over 65 years of age and particularly in women is higher than in younger individuals. Data suggest that compounds with long elimination half life increase the risk further. In patients at risk it is therefore advisable to start treatment with the lowest potentially effective dosage and to avoid compounds with long half lives as first line treatment. NSAID are today the most frequent cause of drug induced renal damage. The renal function disturbances induced by NSAID are largely due to inhibition of renal prostaglandin synthesis. In patients with underlying risk factors NSAID can cause acute renal failure, salt and water retention and hyperkalemia. Because of a progressive decline in renal function and alterations in water and electrolyte homeostasis with aging, elderly patients taking NSAID are particularly at risk of developing renal disease.

Aged↗
PubMed1988

Inhibition of HSV-1 and vaccinia virus replication by cephalosporin derivatives.

Derivatives of beta-lactam antibiotics of the cephalosporin type at 0.02-1 mM concentrations interfered with in vitro replication of two DNA-containing viruses, herpes simplex I and vaccinia, but showed no effects on two RNA-viruses, lymphocytic choriomeningitis virus and vesicular stomatitis virus, or on cell viability. The exact structure of the active compounds remains unknown, but opening of the beta-lactam ring appears to be a prerequisite for their formation. Whereas cephalosporin derivatives were most active, no active products were obtained from penicillins and monobactams. The potential of these unexpected antiviral effects of widely used beta-lactam antibiotics remains subject of further study.

Animals↗
PubMed1987

Betalactam antibiotics interfere with eukaryotic DNA-replication by inhibiting DNA polymerase alpha.

Betalactam antibiotics (BLA) are the most widely used antibacterial drugs in practical medicine. Recent experiments suggested that BLA, especially after "aging" in aqueous solutions, have an inhibitory effect on the growth of a variety of cultured human cells by interfering with DNA synthesis (Neftel et al. Cell Biol. Toxicol. 2, 513-521, 1986). Our initial observation that the replicative DNA polymerase alpha might be the target of the action of betalactam compounds (Hübscher et al. Cell Biol Toxicol. 2, 541-548, 1986) is now substantiated due to the following experimental data: (i) extractable DNA polymerase alpha is greatly reduced in cells that had been treated with BLA; (ii) the relative cellular distribution of thymidine and of its phosphorylated derivatives is not affected by BLA; (iii) BLA inhibit crude and highly purified mammalian DNA polymerase alpha; (iv) the inhibitory effect appears to be of the mixed type with a slight deviation from purely non-competitive behaviour towards the four deoxyribonucleoside triphosphates and; (v) the inhibition is evident in aphidicolin sensitive DNA polymerases from mammalian tissues and in DNA polymerases from DNA viruses such as Herpes simplex and Vaccinia. In sum, the results suggest that one of the most commonly used class of drugs has a target within eukaryotic cells being most likely the replicative DNA polymerase alpha.

Anti-Bacterial Agents↗