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Biomedical subjects

R Lang

Publications and source records attributed to R Lang.

At least 91 records · Page 5Linked to original sources
PubMed1996

Impaired bacteriologic response to oral cephalosporins in acute otitis media caused by pneumococci with intermediate resistance to penicillin.

BACKGROUND: Penicillin resistance of Streptococcus pneumoniae, one of the most common causes of acute otitis media, has recently increased and is now highly prevalent in many regions. However, its contribution to clinical failure still must be proved. Because the role of antibiotics in acute otitis media is to eradicate the pathogens present in the middle ear fluid, we conducted a randomized controlled study to determine bacterial eradication of pathogens in acute otitis media by two commonly used oral cephalosporins, cefuroxime axetil (30 mg/kg/day) and cefaclor (40 mg/kg/day). METHODS: Patients 6 to 36 months old with pneumococcal otitis media seen in the Pediatrics Emergency Room were studied. An initial middle ear fluid culture was obtained at enrollment, and a second culture was obtained on Day 4 or 5 during treatment. Follow-up was done also on Days 10, 17 and 42 after initiation of treatment. In cases of clinical relapse a third culture was obtained. RESULTS: In total 78 patients were enrolled, 41 in the cefuroxime axetil group and 37 in the cefaclor group. Of the 78 S. pneumoniae isolates 31 (40%) were intermediately penicillin-resistant (MIC 0.125 to 1.0 microgram/ml). Of the 47 patients with penicillin-susceptible organisms 3 (6%) had bacteriologic failure vs. 4 of 19 (21%) and 7 of 11 (64%) of those with MIC of 0.125 to 0.25 microgram/ml and 0.38 to 1.0 microgram/ml, respectively (P < 0.001). For intermediately resistant pneumococci, in 7 of 12 (58%) of those receiving cefaclor the isolate was not eradicated vs. only 4 of 19 (21%) of those receiving cefuroxime axetil (P = 0.084). MIC to the administered cephalosporin of > 0.5 microgram/ml was associated with bacteriologic failure. Clinical failure was observed in 9 of 14 (64%) patients with bacteriologic failure vs. 10 of 52 (19%) patients with bacteriologic eradication (P = 0.003). CONCLUSION: Intermediately penicillin-resistant S. pneumoniae is associated with an impaired bacteriologic and clinical response of acute otitis media to cefaclor and cefuroxime axetil. This effect was more pronounced with cefaclor than with cefuroxime axetil.

Acute Disease↗
PubMed1996

A relationship between apoptosis and flow during programmed capillary regression is revealed by vital analysis.

Previous analyses of developmentally programmed capillary regression suggested two distinct causes of vascular endothelial cell (VEC) death. The first appeared to be macrophage-dependent (Lang, R. A. and Bishop, M. J. (1993) Cell 74, 453-462) while the second was proposed to result from cessation of blood flow (Lang, R. A., Lustig, M., Francois, F., Sellinger, M. and Plesken, H. (1994). Development 120, 3395-3403). Combined, these analyses suggested a model in which initial, macrophage-mediated endothelial cell apoptosis blocked blood flow within a capillary segment and, as a consequence, caused apoptosis of all remaining cells in the affected segment. In the current study, we have tested this model using a new method that combines vital and histological analyses as a means of determining the fate of whole capillary segments and individual cells in vivo. This technique revealed that one of the first events in regression was the apoptosis of a single VEC in otherwise normal, flowing capillary segments (initiating apoptosis). These isolated, dying VECs projected into and restricted the capillary lumen, imposing either a temporary or permanent block to blood flow. Following cessation of flow, synchronous apoptosis of VECs occurred (secondary apoptosis). In addition, a quantitative analysis revealed a reciprocal relationship between plasma flow and VEC apoptosis. These observations are consistent with a model for capillary regression in which macrophages induce apoptosis in a limited number of VECs and, as a consequence of a block to blood flow, also cause apoptosis in those remaining.

Animals↗
PubMed1995

Chromatographic techniques--the basis of doping control.

The principal definition of doping, the groups of banned compounds and the basic analytical problems and strategy of doping analysis are outlined, and the position of chromatography in doping analysis is explained. Examples of the application of GC-MS, especially high-resolution MS. and of LC-thermospray MS to doping problems are given. A practical case is presented briefly, showing the post-analytical problem of evaluating even unequivocal results.

Anabolic Agents↗
PubMed1995

Cytotoxic T cells specific for glutamic acid decarboxylase in autoimmune diabetes.

Insulin-dependent diabetes mellitus (IDDM) is an autoimmune disease that results in the destruction of the pancreatic islet beta cells. Glutamic acid decarboxylase (GAD) has been recently indicated as a key autoantigen in the induction of IDDM in nonobese diabetic mice. In human diabetes, the mechanism by which the beta cells are destroyed is still unknown. Here we report the first evidence for the presence of GAD-specific cytotoxic T cells in asymptomatic and recent diabetic patients. GAD65 peptides displaying the human histocompatibility leukocyte antigen (HLA)-A*0201 binding motif have been synthesized. One of these peptides, GAD114-123, binds to HLA-A*0201 molecules in an HLA assembly assay. Peripheral blood mononuclear cells from individuals with preclinical IDDM, recent-onset IDDM, and from healthy controls were stimulated in vitro with the selected peptide in the presence of autologous antigen-presenting cells. In three cases (one preclinical IDDM and two recent-onset IDDM), we detected specific killing of autologous antigen-presenting cells when incubated with GAD114-123 peptide or when infected with a recombinant vaccinia virus expressing GAD65. These patients were the only three carrying the HLA-A*0201 allele among the subjects studied. Our finding suggests that GAD-specific cytotoxic T lymphocytes may play a critical role in the initial events of IDDM.

Adolescent↗
PubMed1995

Differential effects of the immunosuppressive agents cyclosporine and leflunomide in vivo. Leflunomide blocks clonal T cell expansion yet allows production of lymphokines and manifestation of T cell-mediated shock.

The effects of leflunomide and CsA on immune responses in vitro and in vivo were investigated. Like CsA, leflunomide inhibited mitogen- or antigen-driven T cell proliferation in vitro. However, leflunomide impaired neither the capability of T cells to produce IL-2 and IL-4, nor the expression of IL-2R, that is, the acquisition of competence. In contrast to CsA, the IL-2-driven growth of secondary T cells was blocked by leflunomide. Cell cycle analyses revealed that activated T cells did not enter S phase of the cell cycle in the presence of leflunomide. Next, the effects of leflunomide and CsA on the T cell response toward the bacterial superantigen (SAg) staphylococcal enterotoxin B (SEB) were analyzed in vivo. SEB-induced early deletion (apoptosis) of a fraction of SEB-reactive V beta 8+ T cells and IL-2R expression were not impaired by either CsA nor leflunomide. On the other hand, both CsA and leflunomide prevented V beta 8-selective clonal T cell expansion and generation of SEB-specific cytolytic activity. In contrast to CsA, leflunomide treatment permitted in vivo SEB-induced production of T cell-derived lymphokines (IL-2 and TNF). Further, leflunomide failed to protect D-galactosamine-sensitized mice from SEB-induced, T cell-mediated lethal shock, whereas CsA was fully protective. Manifestation of SEB-induced T cell anergy was not impaired by leflunomide. Our results provide evidence that CsA and leflunomide differ significantly in their functional properties to suppress immune responses in that both agents inhibit T cell functions linked to clonal expansion, while leflunomide does not inhibit lymphokine secretion and thus permits lymphokine-mediated immune functions.

Animals↗
PubMed1995

Different techniques of laparoscopic end-to-end small-bowel anastomoses.

The aim of the study was to prove that laparoscopic stapling devices can be used to create a bowel anastomosis. Three groups with n = 6 pigs each were subjected to different techniques of small-bowel anastomoses. In groups I and II anastomosing of the bowel ends was carried out with singly placed staples using a hernia stapler. (Group I: Two-thirds of the circumference became inverted and one-third everted. Group II circumferentially everted). In group III triangular everted anastomoses were produced using a linear noncutting stapler. All animals survived the observation period of 14 days and were postmortally examined. Average construction time was 59 min for groups I and III and 47 min for group II. Average diameters were 14 mm, 16 mm, and 18 mm for groups I, II, and III, respectively. There were no significant differences between the techniques concerning the stability of the anastomoses as expressed by bursting pressures. There were two stenoses in group I animals caused by electrocautery during preparation of the bowel ends prior to anastomosing. Anastomotic insufficiencies or fistulas were not observed clinically or with Gastrografin studies. We conclude that anastomoses in the pig can laparoscopically be constructed by employing singly placed staples as well as a linear stapler. Further investigations of these techniques on large bowel and human specimens are required prior to their clinical use in humans.

Anastomosis, Surgical↗
PubMed1995

Chronic Q fever of pregnancy presenting as Coxiella burnetii placentitis: successful outcome following therapy with erythromycin and rifampin.

Chronic Q fever has been associated with endocarditis, granulomatous hepatitis, and osteomyelitis but only rarely with pregnancy. The apparent predilection of Coxiella burnetii, the organism causing Q fever, for the human placenta suggests that chronic Q fever of pregnancy is due to placentitis. We describe a patient with chronic, clinically apparent Q fever in pregnancy and a successful outcome. The diagnosis was made both by serology and by isolation of C. burnetii from the patient's serum and placenta. Therapy with erythromycin and rifampin contributed to the delivery of a healthy baby. The mother's infection was clinically cured by subsequent therapy with doxycycline and rifampin.

Adult↗
PubMed1995

Fungal endocarditis.

Fungal endocarditis has become an important infection associated with medical progress and a modern lifestyle. The most common organisms isolated from patients with fungal endocarditis are: Aspergillus spp.; Candida spp. and Torulopsis glabrata. Men are more frequently affected than women and predisposing factors include: previous cardiac surgery, antibiotic use and hyperalimentation, long-term i.v. catheters. Common clinical findings in patients with endocarditis include: fever, changing murmurs, peripheral emboli which are characteristically large and chorioretinitis. Characteristic laboratory findings are absent and positive blood cultures are obtained only in a relatively small number of patients. Characteristically, Aspergillus spp. almost never grow in blood cultures and must be isolated from removed emboli, from the diseased valve or from infected foreign bodies. Overall survival in patients with fungal endocarditis is rather poor, and hardly exceeds 50%. In general, a combined surgical-medical approach would yield the best results. New therapeutic modalities are needed in order to improve the prognosis of fungal endocarditis.

Endocarditis↗
PubMed1995

Anxiety disorders among patients in a general emergency service in Israel.

OBJECTIVE: Several studies have suggested that many patients with anxiety disorders present in nonpsychiatric medical settings such as primary care facilities, emergency services, and general practice. This study examined the prevalence of panic disorder and generalized anxiety disorder among patients admitted to the general emergency service at an urban medical center in Israel. METHODS: Four groups totaling 517 patients were assessed. The groups consisted of patients presenting with somatic complaints for whom no physical condition was diagnosed, patients with somatic complaints found to have a physical disorder, a group of nonpsychiatric consecutive admissions to the emergency service, and a group of referrals to the psychiatric emergency service. RESULTS: The prevalence of panic disorder and generalized anxiety disorder in the entire sample was 2.7 percent, which is comparable to the prevalence rates reported in various community studies. However, the prevalence among patients with somatic complaints but no physical disorder was 6.7 percent, significantly higher than in the nonpsychiatric comparison groups. The prevalence in the group of psychiatric referrals was 4.8 percent. CONCLUSIONS: A population at risk for higher prevalence of anxiety disorders can be identified among patients seen in an emergency service. Physicians in primary care settings and general emergency services should consider anxiety disorders in the differential diagnosis of patients with somatic complaints but without a diagnosis of physical disorder.

Adolescent↗
PubMed1995

Sequential levels of ceftriaxone in intervertebral disc removed as part of scoliosis surgery.

A single intravenous loading dose of 1 g ceftriaxone was injected at different intervals before surgery for correction of spinal scoliosis. Serum and concomitant disc samples were obtained and assay was performed using high-pressure liquid chromatography. Data showed that the antibiotic levels in intervertebral disc space reached 3.5 mcg/mg, which is above the minimum inhibitory concentration for most of the relevant pathogens, as early as 1 hour after intravenous administration. These therapeutic levels were maintained for more than 5 hours, an accepted period for most spinal surgical procedures.

Adult↗
PubMed1995

Acute and chronic effects of winter swimming on LH, FSH, prolactin, growth hormone, TSH, cortisol, serum glucose and insulin.

The present investigation is based on a 2.5 months selbstversuch (self-experiment) of the authors, between October 21 1992, and January 6 1993. 11 healthy students, five females and six males, age 24 to 29 years, and their teachers underwent regular winter swimming at least once a week, for 2 to 10 minutes, at the natural water temperature (6.8 degrees C (October 1992) to 2.0 degrees C (January 1993)) in the southern Baltic Sea. Blood samples were drawn before and 30 and 60 minutes after the cold bath, both at the first and the last day of the swimming season. TSH increased from 0.96 mU/l to 1.42 mU/l (p < 0.01) in the untrained, and from 0.93 mU/l to 1.43 mU/l (p < 0.01) in the cold-trained persons, and decreased thereafter (p < 0.01). Similar changes occurred in cortisol serum concentrations, though psychological stress seemed to interfere with cold stress. Cortisol increased from 99 ng/ml to 133 ng/ml in the untrained, and from 101 ng/ml to 137 ng/ml (p < 0.05) in the cold-trained persons within 30 minutes after cold water immersion, and decreased thereafter (p < 0.01). There were mild decreases in prolactin serum levels after cold stress, whereas FSH, LH and growth hormone remained unaltered. There was a mild initial elevation of serum glucose after cold stress (plus 12 mg/dl, (p < 0.01)) which disappeared after training. There were long term training effects besides the effects on glucose: Basal prolactin levels increased by almost the factor two, and insulin serum levels dropped by almost 50%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Lateral sinus thrombophlebitis].

Lateral sinus thrombophlebitis (LST) is an intracranial complication of otitis media. Its incidence has markedly decreased in the era of antibiotic therapy but mortality is still high. A 13-year-old girl presented with fever, ear discharge and torticollis. On the day of admission LST was diagnosed from the clinical presentation and CT-scan. She was operated immediately and intravenous antibiotics were administered. Despite the rapid intervention, the course was protracted, with recurrent events of septic pulmonary embolism. Despite internal jugular vein ligation, fever continued and anticoagulant therapy was begun. The possibility of LST should be considered in patients with ear discharge and fever. CT-scan enables early diagnosis of LST and MRI has a role in detecting additional intracranial septal foci. Surgical intervention should be early and aggressive. The efficacy of jugular vein ligation is unclear; anticoagulant therapy should be considered.

Adolescent↗