Search PubMed⌕ Search

Biomedical subjects

R Lang

Publications and source records attributed to R Lang.

At least 73 records · Page 4Linked to original sources

Complication rate with prosthodontic reconstructions on ITI and IMZ dental implants. Internationales Team für Implantologie.

The aim of this study was to compare the complication rate of two implant systems with different prosthodontic concepts: rigid conical or resilient support of the suprastructure. In 66 patients, 138 ITI implants were inserted whereas 31 patients received a total of 50 IMZ implants. Over an average observation period of 3.5 years (range from 0.5 to 8 years), not only was implant survival recorded, but also prosthodontic complications such as screw loosening, fractures of screws, inserts (intramobile elements, intramobile connectors) and abutments, as well as fractures of metal framework and veneers. With the ITI system, 28.8% of all devices placed exhibited such problems during the observation period. With the IMZ system, this rate was significantly higher (P < 0.05), in that 77.4% of all reconstructions required a repair at some point. The various complications were divided into those occurrences which affected only the suprastructure, i.e., failures of frameworks, veneers, bar devices or other retentive elements, and those which involved implant components per se, such as screws and abutment components. In the first category, adverse effects occurred more frequently with ITI-supported prostheses (15.1%) versus IMZ suprastructures (6.4%). Regarding complications with implant components, the rate with IMZ components was considerably higher (71%) compared with ITI (13.5%). This was mainly due to the presence of intramobile elements (IME) and connectors (IMC) in the IMZ system. In this retrospective study, precise fitting, non-resilient abutment components leading to rigid connections of suprastructures, proved to be clinically more successful than resilient anchoring components.

Adolescent↗

Imported severe falciparum malaria in Israel.

Malaria remains an overwhelming problem in tropical developing countries, with 300 to 500 million new cases and 1.5 to 3.5 million deaths per year. Malaria is a potentially life-threatening disease for travelers to the tropics. Imported malaria is an important clinical problem in nonendemic areas of the world because of increasing numbers of travelers, overseas workers, and immigrants from endemic areas. According to the World Health Organization's criteria, the recognition of one or more of the following clinical features should raise the suspicion of severe malaria: cerebral malaria (unrousable coma), severe anemia (hemoglobin <5 g/dL), renal failure (serum creatinine >3 mg/dL), pulmonary edema or adult respiratory distress syndrome, hypoglycemia (glucose <40 mg/dL), circulatory collapse or shock, disseminated intravascular coagulation, repeated generalized convulsions, acidosis (pH <7.25), macroscopic hemoglobinuria, hyperparasitemia (>5 percent of the erythrocytes infested by parasites), or jaundice (bilirubin >3 mg/dL). Although only a small proportion of patients with malaria develops severe manifestations, these patients require the most urgent and intensive care. Mortality among patients with cerebral malaria, even when treated in modern intensive care units, exceeds 30%, and when complicated by the adult respiratory distress syndrome, it may approach 80%. Among travelers, mortality remains a serious issue because of failure to obtain and use preventive measures, delay in seeking medical attention, and misdiagnosis.

Adult↗

Risedronate in the treatment of Paget's disease of bone: an open label, multicenter study.

An open-label, multicenter study was conducted to determine the efficacy and safety of oral risedronate (a pyridinyl bisphosphonate) in 162 patients (102 men, 60 postmenopausal women; mean age, 68 years) with moderate to severe Paget's disease of bone (mean serum alkaline phosphatase [ALP] approximately seven times the upper limit of normal). Patients were treated with oral risedronate, 30 mg/day for 84 days, followed by 112 days without treatment. This 196-day cycle was repeated once if serum ALP did not normalize or increased from the nadir value by > or = 25%. At the end of the first and second cycles, the mean percentage decreases for serum ALP were 65.7% and 69.1%, and for urinary hydroxyproline/creatinine 50.4% and 66.9%, respectively. The decreases from baseline in ALP and urinary hydroxyproline/creatinine were significant (p < 0.001). Normalization of serum ALP was observed in 86 patients (53.8%): 53 during the first treatment cycle and 33 during the second. There was a significant proportion of patients reporting a decrease in the pagetic bone pain at days 84 and 196 (p < 0.001). Overall, risedronate was well tolerated. Five patients withdrew due to adverse events, none of which were considered to be drug related. In conclusion, 30 mg of oral risedronate administered daily for 84 days significantly reduced the biochemical indices of disease activity and was associated with pain reduction in patients with moderate to severe Paget's disease of bone. Normalization of ALP was observed in the majority of patients. Repeated administration of risedronate was shown to be beneficial. In general, risedronate was well tolerated and demonstrated a good safety profile.

Administration, Oral↗

Transient bradycardia induced by carotid sinus pressure increases outflow obstruction in hypertrophic obstructive cardiomyopathy but not in valvular aortic stenosis.

BACKGROUND: The murmur of hypertrophic obstructive cardiomyopathy (HOCM) increases in intensity in about 80% of those patients in whom carotid sinus pressure (CSP) slows the heart rate. This does not occur in valvular aortic stenosis (AS). STUDY OBJECTIVES, DESIGN, AND PATIENTS: It was hypothesized that left ventricular (LV) obstruction increases with CSP in HOCM and not in AS. Furthermore, it was not clear whether it was the sudden bradycardia or CSP itself that was responsible for the effect noted. Therefore, studies were performed using two different interventions: (1) Doppler echocardiography was performed before and during CSP in 36 HOCM patients and 21 AS patients; (2) two patients with DDD pacemakers and HOCM were examined before and after pacemaker rate slowing. Finally, atrial pacing was performed in three HOCM patients at catheterization, and atrial pacing was either slowed or stopped (without CSP). RESULTS: LV outflow velocity and pressure gradient increased in 28 of 30 HOCM patients (92%) in whom heart rate decreased with CSP. The peak instantaneous pressure gradient increased from 45+/-37 to 77+/-53 mm Hg (p<0.005), and the velocity contour became more typical of HOCM. The pressure gradient increased from 30 mm Hg to 64 and 81 mm Hg, respectively, in the two patients with DDD pacemakers after pacemaker rate slowing. Similar results were seen with slowing or cessation of atrial pacing at catheterization. In contrast, the pressure gradient increased in only three of 21 AS patients (14%), to 44+/-28 from 41+/-25 mm Hg, and remained unchanged in the other 18. CONCLUSION: This study shows that LV outflow velocity and pressure gradient increase markedly in most HOCM patients (92%) if CSP succeeds in slowing the heart rate, but not in patients with valvular AS. A similar effect is obtained by simply decreasing the atrial rate in patients with DDD or atrial pacemakers. This increase in outflow tract obstruction is sufficient to account for the increase in murmur intensity. Decreased afterload (secondary to greater aortic decompression with the longer diastole), increased intrinsic force of contraction with the bradycardia (the Woodworth effect), and Starling's law may play independent roles in the dynamic increase in obstruction observed during CSP in patients with HOCM. Worsening of mitral regurgitation was not clearly shown to contribute to the increase in murmur, but it cannot readily be ruled out.

Adult↗

Aztreonam plus piperacillin--empiric treatment of neutropenic fever in gynecology-oncology patients receiving cisplatin-based chemotherapy.

Antibiotic therapy must be instituted promptly and on an empiric basis in neutropenic patients. We evaluated the efficacy of a combined antibiotic regimen of monobactam (aztreonam) and antipseudomonal penicillin (piperacillin) in treating neutropenic fever episodes in gynecologic-oncology patients receiving cisplatin-based chemotherapy. A retrospective analysis of response to this regimen was performed. The rationale of this combination is the lack of nephrotoxicity and ototoxicity in patients who are or were previously treated with other nephrotoxic/ototoxic agents like cisplatin. A total of 19 courses of this regimen was administered to 13 patients with neutropenic fever following a complete fever work-up. Aztreonam (1-2gr q8h) plus piperacillin (4gr q8h) were administered intravenously for 6-8 days. Blood cultures were positive in four febrile episodes, and urine cultures were positive in seven. Gram negative organisms accounted for all positive cultures. The cultured organism showed in-vitro sensitivity to at least one of the drugs in all positive isolates. Clinical response with defervescence was noted during therapy in 18/19 courses (94.7%). Although the two drugs share a common bactericidal mechanism they were found to be highly active in this subgroup of patients. A double blind prospective evaluation of this empiric combination is warranted.

Adult↗

Beta2-agonists prevent Th1 development by selective inhibition of interleukin 12.

Interleukin 12 (IL-12) plays a central role in the immune system by skewing the immune response towards T helper 1 (Th1) type responses which are characterized by high interferon-gamma and low IL-4 production. In this report we present evidence that beta2-agonists inhibit IL-12 production by both human monocytes in response to lipopolysaccharide (LPS) and dendritic cells stimulated via CD40. Inhibition of IL-12 production is selective, as other cytokines produced by monocytes are unaffected. IL-12 inhibition is dependent on beta2-adrenoceptor stimulation and correlates with increased levels of intracellular cAMP. In conjunction with their ability to suppress IL-12 production, when beta2-agonists are added at priming of neonatal T lymphocytes, they inhibit the development of Th1-type cells, while promoting T helper 2 (Th2) cell differentiation. Further, the in vivo administration of a therapeutic dose of salbutamol results in the selective inhibition of IL-12 production by whole blood lymphocytes stimulated in vitro with LPS. These findings provide new insight into the immunological consequences of the clinical use of beta2-agonists and may suggest new approaches for the treatment of Th1-mediated diseases.

Adrenergic beta-2 Receptor Agonists↗

A rapid method for semiquantitative analysis of the human V beta-repertoire using TaqManR PCR.

Analysis of the V beta-repertoire of antigen-reactive T cell populations can be approached using either flow-cytometry or PCR-based techniques. While the former method requires a complete set of V beta-specific monoclonal antibodies (mAbs) and large cell numbers for analysis, the latter is both time-consuming and labour-intensive. To circumvent the drawbacks of both these methods we have employed the recently developed technique of TaqManR PCR to analyse the V beta-usage of human T cell populations. TaqManR PCR is based on the 5'-->3' nuclease activity of Taq polymerase. During PCR amplification an internal oligonucleotide probe, that is labelled with a fluorescent reporter and a quencher dye, is cleaved by Taq polymerase. After cleavage, quenching of the reporter dye is lost and reporter fluorescence can be detected with a fluorescence plate reader. Using one C beta-specific fluorogenic probe and a panel of V beta-specific primers, we show that fluorescence-detected amplification of TCR beta cDNA is V beta-specific and linear within a 2-3-log range of template concentration. The sensitivity of TaqManR PCR is comparable to conventional detection of PCR-products by agarose gel staining, while processing time is reduced. Furthermore, superantigen-induced skewing of the V beta-repertoire of human T cells is readily detected with this method. Thus TaqManR PCR is a reliable and fast method for semiquantitative analysis of the V beta-repertoire of human T cell populations.

Cells, Cultured↗

Cardiovascular complications of malignant carcinoid disease.

Carcinoid tumors are endocrinologic malignancies often associated with a characteristic syndrome-the malignant carcinoid syndrome. Cardiovascular manifestations of this rare illness result from unique pathophysiologic characteristics, are associated with poor prognosis, and are difficult to treat medically. The hemodynamic consequences of this disease present unique management problems perioperatively. New pharmacologic and surgical therapies for malignant carcinoids have improved quality of life for patients to the extent that carcinoid heart disease now has more impact on morbidity and mortality rates. Cardiologists may be called on to diagnose and treat this rare cardiac disease. We review, for consulting cardiologists, the pathophysiologic characteristics, cardiovascular manifestations, and management of this disease.

Cardiovascular Diseases↗

Bacteriologic response to oral cephalosporins: are established susceptibility breakpoints appropriate in the case of acute otitis media?

Bacteriologic response to cefuroxime axetil and cefaclor administered for 10 days was evaluated in acute otitis media (AOM) in patients aged 6-36 months. Middle ear fluid culture was obtained by tympanocentesis before treatment, on day 4 or 5 after initiation of treatment, and if clinical relapse occurred before day 17. Bacteriologic failure was observed in 32% of patients receiving cefaclor versus 15% of patients receiving cefuroxime axetil (P = .009). Failure rates increased with increasing MIC: For Streptococcus pneumoniae, 0.5 microg/mL (established as cutoff value for cefuroxime by the National Committee for Clinical Laboratory Standards [NCCLS]) discriminated between success and failure. For Haemophilus influenzae, high failure rates were observed for cefaclor, even with low MICs (< or = 1.0 microg/mL), and with both drugs they tended to increase with increasing MIC, even for values below the cutoff suggested by the NCCLS (8.0 and 4.0 microg/mL for cefaclor and cefuroxime, respectively). Thus, for AOM caused by H. influenzae, lower susceptibility cutoff levels for MICs should be established.

Acute Disease↗

Colour stability of visible light-curing hybrid composites.

The colour stability of six visible light-curing fine hybrid composites was evaluated after 24 and 120 hours of irradiation using a xenon lamp. Discoloration of four shades of each material (A1, A2, A3.5 and B2- Vita shade guide) was measured using a reflection spectrophotometer with the CIE-L*a*b* system. The discoloration after 24 hours of irradiation had values of between 0.7 and 3.8 DE*, and was therefore, with the exception of Z 100 (colours A1 and B2), clinically acceptable. The results showed that the differences in colour of all shades of Pekafill NF and Tetric tested were significantly less than those of the other products. All samples, with the exception of Pekafill NF (A3.5 and B2), showed increased discoloration to values of 3.7 to 7.8 DE* after 120 hours of exposure to UV light. In general, all the composites tended to become more yellow (b*), darker (L*) and slightly greener (a*).

Analysis of Variance↗

Long-term renoprotective effect of angiotensin-converting enzyme inhibition in non-insulin-dependent diabetes mellitus. A 7-year follow-up study.

BACKGROUND: Diabetic nephropathy is the leading cause of end-stage renal disease in developed countries. Duration of diabetes, blood pressure values, and metabolic status are the major determinants of the course of nephropathy, and microalbuminuria is the hallmark of its onset. Angiotensin-converting enzyme inhibitors offer important renoprotection to hypertensive and normotensive patients with insulin-dependent diabetes mellitus and non-insulin-dependent diabetes mellitus. Our study extends previous observations for duration and the effect of angiotensin-converting enzyme inhibition on advanced nephropathy. METHODS: Double-blinded (first phase) and open (second phase) randomized controlled study of 7 years. Ninety-four normotensive patients with non-insulin-dependent diabetes mellitus whose serum creatinine levels were lower than 123.76 mumol/L (1.4 mg/dL) and who had microalbuminuria (30 to 300 mg/24 h) were given enalapril maleate, 10 mg/d, or placebo, for 5 years. For 2 more years they were followed up openly and given the choice to receive enalapril or no treatment. RESULTS: In the enalapril-treated patients, albuminuria remained stable for 7 years. An increase from (mean +/- SD) 123 +/- 58 to 310 +/- 167 mg/24 h occurred in the untreated group after 5 years, and a further increase to (mean +/- SD) 393 +/- 223 mg/24 h occurred after 7 years. Reciprocal creatinine was unchanged in treated patients for 7 years; in the untreated patients, the mean decline was 13% at 5 years and 16% at 7 years. Treatment with enalapril resulted in an absolute risk reduction of 42% for nephropathy to develop during 7 years (95% confidence interval, 15% to 69%; P < .001, Student's t test). Glycosylated hemoglobin and body mass index remained unchanged. CONCLUSIONS: Angiotensin-converting enzyme inhibition offers long-term protection against the development of nephropathy in normotensive patients with noninsulin-dependent diabetes mellitus who have microalbuminuria, and it stabilizes renal function in previously untreated patients with impaired renal function. Discontinuation of treatment results in renewed progression of nephropathy.

Adult↗

Studies for a genotoxic potential of some endogenous and exogenous sex steroids. II. Communication: examination for the induction of cytogenetic damage using the chromosomal aberration assay on human lymphocytes in vitro and the mouse bone marrow micronucleus test in vivo.

The cytogenetic potential of 10 sex steroids (cyproterone acetate, drospirenone, gestodene, cyclodiol, cyclotriol, ethinylestradiol, atamestane, lilopristone, onapristone and propylmesterolone) with various medical indications was determined using the chromosomal aberration test in human lymphocytes in vitro and the mouse bone marrow micronucleus test in vivo. Nine of these sex steroids (gestodene was omitted) were investigated in the human lymphocyte assay and found to be negative with respect to the induction of chromosomal aberrations either with or without metabolic activation. In all assays the highest concentration evaluated was either clearly cytotoxic or, in case of noncytotoxicity, resulted in visible precipitates in the culture medium. Evaluation of the data from the mouse bone marrow micronucleus test indicated that the seven steroids (cyproterone acetate, drospirenone, gestodene, ethinylestradiol, atamestane, onapristone and propylmesterolone) investigated failed to induce enhanced frequencies of micronucleated polychromatic erythrocytes in male and female mice. The steroids were tested up to dose levels which induced signs of toxicity in the experimental animals or, in the case of non toxic compounds, the animals were treated up to the maximum recommended dose of 2 g/kg body weight. Evaluation of all data indicates that the investigated estrogens, progestins and other sex steroids had no genotoxic potential detectable with the chromosomal aberration assay on cultured human lymphocytes or the mouse bone marrow micronucleus test.

Animals↗

Childhood brucellosis in Israel.

BACKGROUND: Brucellosis has become a major medical problem in Israel particularly in the Muslim Arab population. METHODS: Eighty-eight children with acute brucellosis are described. Sixty-seven were studied retrospectively during 1987 through 1988, and 21 children were studied prospectively during 1989 through 1992. Epidemiologic, clinical and laboratory features were evaluated, and the outcome of 4 antimicrobial regimens are compared. RESULTS: Although the clinical manifestation varied, the classical triad of fever (91%), arthralgia or arthritis (83%) and hepato- and/or splenomegaly (63%) characterized most patients. Sixty-one percent of the children had elevated liver enzymes. Brucella melitensis was isolated from 61% of blood cultures. The relapse rate in patients who were treated with monotherapy (doxycycline) was 43% compared with 14% with regimens of combined therapy with rifampin and doxycycline, streptomycin and doxycycline or rifampin and trimethoprim-sulfamethoxazole (P < 0.049). Eleven children (33%) who were treated for 3 weeks had relapse compared with 1 patient (3.5%) treated for 4 weeks or longer. The total relapse or reinfection rate was 20%. All patients with relapse recovered after a second course of antibiotic therapy. During the 2 years of follow-up one child progressed to chronic osteomyelitis. CONCLUSIONS: Combination therapy and extending treatment for 4 weeks or longer gave significantly better results than monotherapy or shorter courses of therapy and resulted in fewer relapses.

Adolescent↗