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Biomedical subjects

H Lang

Publications and source records attributed to H Lang.

At least 109 records · Page 6Linked to original sources
PubMed1997

Flow cytometry cross-match: a method for predicting graft rejection.

Long-term graft survival is mainly influenced by early graft rejection and posttransplant graft function. The ability of both complement-dependent cytotoxicity cross-match (CDC) and flow cytometry cross-match (FCXM) to predict acute rejection episodes has been evaluated by cross-matching 40 patients who received cadaveric kidney transplants, before (current serum) and after transplantation (on days 1, 7, 14, 21, 28, 60, and 90). Of the 40 patients, all of whom had a negative CDC before transplant, seven patients had a positive FCXM before transplant: five of them (5/7=71.4%) experienced severe rejection within 2 months after transplantation. In patients with a negative FCXM before transplant, the incidence of acute rejection was lower (25.8%). Pre-transplant FCXM recipients who had a positive FCXM after transplant, experienced more frequent rejection (38.5%) than those pre-transplant FCXM recipients who never had a positive FCXM (15.8%). With respect to the incidence of acute graft rejection, no difference was found between patients who had a positive CDC after transplant and those who had a negative CDC after transplant. Patients who had a positive FCXM before transplant had significantly higher creatinine levels within the first month after transplant. Immediate onset of function and accelerated lowering of the creatinine level were found to be more frequent in patients who had a negative FCXM before transplant. As early graft rejection is the largest contributing factor for the development of chronic rejection and, therefore, of graft loss, we regard FCXM as a sensitive method for predicting long-term prognosis and graft survival, due to its competence in predicting both restricted graft function and early acute rejection, in particular.

Complement System Proteins↗
PubMed1997

[Tumors of the upper excretory tract].

Most tumors of the upper urinary tract are epithelial tumors from transitional cell origin. They are more frequent in the renal pelvis than in the ureter. They may be single or multiple and rarely bilateral. Gross hematuria is the most common presenting form. Computed tomography is useful both in the diagnosis and staging and is much more contributive than intravenous pyelography. Nephroureterectomy with a bladder cuff is the standard treatment for upper tract tumors. In selected cases are low grade and low stage tumors, conservative surgery can be discussed with similar longterm results than radical surgery.

Humans↗
PubMed1997

[Surgery in immunosuppressed patients with emergency or elective indications].

Immunosuppressive therapy and its influence on perioperative pathophysiology present special challenges in the event of surgical intervention. Immunosuppressive agents alter the patient's response to surgical stress and infectious complications. The often masked signs, even in the case of severe infection, require a high index of suspicion to establish the diagnosis. This may result in a fatal delay of therapy. In addition, the immunosuppressed state increases the patient's susceptibility to infection and leads to an impairment of wound healing. Therefore, careful perioperative clinical monitoring of the patient and complete control of the immunosuppressive therapy are mandatory. Elective operations in immunosuppressed patients should be performed with special caution regarding the potential perioperative risks for the patient and the graft. On the other hand, if there is evidence of, for example, an acute abdominal event, a more aggressive approach is required to rapidly establish the diagnosis and institute appropriate therapy. From the surgical point of view, special emphasis should be placed on wound closure and on anastomotic sutures when operating on a patient receiving immunosuppressive therapy.

Elective Surgical Procedures↗
PubMed1997

Inhibition instead of enhancement of lipid peroxidation by pretreatment with the carcinogenic peroxisome proliferator nafenopin in rat liver exposed to a high single dose of corn oil.

Oxidative stress is discussed as a possible hepatocarcinogenic mechanism of peroxisome proliferators (PP) in rodents and is suggested to result from the induction of peroxisomal beta-oxidation (PBOX) by PP. The induced PBOX is assumed to produce excessive H2O2 from the degradation of fatty acids, ultimately leading to oxidative stress and lipid peroxidation. In the present short term-study, we attempted to stimulate lipid peroxidation in male Wistar rats by (1) inducing PBOX enzymes with the peroxisome proliferator nafenopin at 90 mg/kg body weight per day in the diet for 10-11 days, and (2) by supplying the induced PBOX with an abundant amount of fatty acid as substrate, using a corn oil gavage at 20 ml/kg body weight. The corn-oil gavage alone, i.e. without preceding nafenopin treatment, enhanced liver triacylglycerol nine- to tenfold and hepatic lipid peroxidation, measured as thiobarbituric acid reactive substances (TBARS), was increased 50% compared with controls. Both observations were made after 18 h when the peak elevations occurred. Upon pretreatment with nafenopin, associated with a sevenfold induction of PBOX, the corn oil gavage however caused only a threefold maximal increase in hepatic triacylglycerol, also at the 18 h time-point; TBARS remained almost at control levels, as monitored at seven time points over 24-25 h. These results suggest that nafenopin reduces rather than enhances lipid peroxidation, despite the provision, in a short term study, of high doses of substrate to the induced enzyme system that is hypothetically causing oxidative stress in the liver.

Animals↗
PubMed1997

Tone duration discrimination in Parkinson's disease.

Patients with Parkinson's disease (PD) and healthy controls took a computerized test of tone duration discrimination (TDD) using pairs of tones of 0.4-1.6 sec duration, presented at intervals of 0.5-4 sec. In PD patients as well as controls, TDD was impaired by even slight degrees of cognitive deterioration. PD yielded impaired TDD in females, but not in males. This suggests that the dopamine-powered biological clock, which is vulnerable to PD, is more important for the processing of durations in the 1-sec range in women than in men.

Adult↗
PubMed1997

Apoptosis and hair cell degeneration in the vestibular sensory epithelia of the guinea pig following a gentamicin insult.

Apoptosis plays a key role in the steady state of continuously renewing tissues. The goal of this study was to determine whether apoptosis was a mode of hair cell loss in mammalian inner ear sensory epithelia. Hair cell loss was induced by systemic treatment with the ototoxic aminoglycoside antibiotic gentamicin in guinea pig. The vestibular sensory epithelia were examined at different times after administration via semi-thin and thin sections in situ labeling by the terminal deoxynucleotidyl transferase catalysis of digoxigenin tagged nucleotides to the free 3'-OH ends of fragmented DNA. Apoptotic labeling was detected 3-7 days after treatment. The majority of the apoptotic nuclei was found adjacent to the luminal surface. Analysis of semi-thin and thin sections revealed two modes of hair cell degeneration: (1) Apoptosis within the epithelium, showing typical morphological changes of condensation and fragmentation of the nucleus and modifications of cytoplasmic organelles. (2) Swelling of the cell, vacuolation and distortion of cell shape, and extrusion into the lumen. The results indicated that vestibular hair cells undergo apoptosis after ototoxic traumas.

Animals↗
PubMed1997

Hepatic preservation with histidine-tryptophan-ketoglutarate solution in living-related and cadaveric liver transplantation.

1. Living-related liver transplantation has some advantages in the evaluation of novel clinical protocols, since many complicated factors affecting initial graft function are almost uniform in grafts obtained from healthy donors. 2. To compare histidine-tryptophan-ketoglutarate (HTK) and University of Wisconsin (UW) solution in terms of tissue oxygenation in living-related liver transplantation, oxygen saturation of haemoglobin (SO2) in hepatic tissue and its heterogeneity (CV, coefficient of variation) were measured by near-infrared spectroscopy. The HTK and UW groups consisted of 15 and 49 successful transplants respectively, in which no statistical differences in background were observed. 3. In the HTK group, hepatic SO2 after portal vein reflow was higher (P < 0.01) than that in the UW group, as was that after hepatic artery reflow (P < 0.05). In the UW group, hepatic SO2 remained at the lower level at the end of the operation. 4. Furthermore, the increase in CV after portal vein reflow was normalized after hepatic artery reflow in the HTK group. However, the CV remained at a high level at the end of the operation in the UW group. 5. Postoperative peak aspartate aminotransferase level in the HTK group was lower than that in the UW group (P < 0.05). 6. In cadaveric liver transplantation, higher hepatic SO2 and lower CV of hepatic SO2 in the early phase after reperfusion compared with the UW group (n = 18) were also observed in the HTK group (n = 30) (P < 0.05). 7. In conclusion, recovery of tissue oxygenation and its heterogeneity after reperfusion in HTK-preserved livers were more rapid and homogeneous than in UW-preserved livers in living-related liver transplantation. Accordingly, HTK solution may be a potential alternative to UW solution.

Adenosine↗
PubMed1997

Attenuated auditory event-related potential (mismatch negativity) in children with developmental dysphasia.

An attention-independent negative wave-form termed 'mismatch negativity' (MMN) of the auditory event-related potentials (ERPs) was studied in ten children (3-6 years) with developmental dysphasia and in fourteen control children (3-7 years) with normal speech and language development. The MMNs were elicited with pure sine tone stimuli using the oddball paradigm. The peak latency and peak amplitude of MMN response to frequency (500/553 H2) difference was measured. The grand average amplitude of frequency MMN was significantly attenuated in dysphasic children as compared to controls, but no significant difference was observed in the latency of peak frequency MMN. The results indicate that dysphasic children have a defect in automatic auditory processing of frequency differences. Because the MMN response reflects central auditory processing and is modal specific for auditory stimuli we argue that the MMN method can serve as an objective tool to assess central auditory deficits in children.

Analysis of Variance↗
PubMed1997

[The clientel of a psychotherapeutic polyclinic in the light of a documentation base].

A documentation system for use during the diagnostical process with psychotherapy outpatients is outlined, and sociodemographic, medical and psychosocial data of newly admitted patients of a university psychotherapy outpatient department are presented. The population structure is described on the basis of data collected during the first 18 months of the implementation of the assessment system. Data are compared with those of other psychotherapeutical institutions that differ with regard to setting (outpatient vs. inpatient), health care sector (acute care vs rehabilitation) and geographic region. Sociodemographic and medical data are given. Patients' mean age is 33.5 years. Two-thirds of the patients are female. The majority is single and has higher formal education. Slightly more than half of the patients are working. Modes of admittance, somatic and psychological complaints and aspects of illness behaviour are described. Pertaining to diagnostical classification, affective disorders (34%), somatoform disorders (15%) and anxiety disorders (11%) are most frequent. Mean duration of symptoms is 6 years. However, only few patients had prior psychological treatment. Treatments most frequently selected at the time of assessment were psychodynamic psychotherapy (41%), behavioural therapy (24%), and group therapy (10%). When comparing the study population with those of other institutions, differences showed up especially in contrast to rehabilitation clinics, where older, male, and working persons as well as those with somatoform disorders and longer durations of illness are more frequent.

Adult↗
PubMed1997

Liver transplantation for metastatic neuroendocrine tumors.

OBJECTIVE: This article describes the experience with liver transplantation in patients with irresectable neuroendocrine hepatic metastases. SUMMARY BACKGROUND DATA: Liver transplantation has become an established therapy in primary liver cancer. On contrast, there is little experience with liver transplantation in secondary hepatic tumors. So far, in the majority of patients being transplanted for irresectable liver metastases, long-term results have been disappointing because of early tumor recurrence. Because of their biologically less aggressive nature, the metastases of neuroendocrine tumors could represent a justified indication for liver grafting. METHODS: In a retrospective study, the data of 12 patients who underwent liver transplantation for irresectable neuroendocrine hepatic metastases were analyzed regarding survival, tumor recurrence, and symptomatic relief. RESULTS: Nine of 12 patients currently are alive with a median survival of 55 months (range, 11.0 days to 103.5 months). The operative mortality was 1 of 12, 2 patients died because of septic complications or tumor recurrences or both 6.5 months and 68.0 months after transplantation. all patients had good symptomatic relief after hepatectomy and transplantation. Four of the nine patients who are alive have no evidence of tumor with a follow-up of 2.0, 57.0, 58.0, and 103.5 months after transplantation. CONCLUSIONS: In selected patients, liver transplantation for irresectable neuroendocrine hepatic metastases may provide not only long-term palliation but even cure. Regarding the shortage of donor organs, liver grafting for neuroendocrine metastases should be considered solely in patients without evidence of extrahepatic tumor manifestation and in whom all other treatment methods are no longer effective.

Adolescent↗
PubMed1997

[Do psychological factors modify survival of cancer patients? II: Results of an empirical study with bronchial carcinoma patients].

The present prospective test study of hypotheses addressed the question whether psychological factors are predictive of survival time in lung cancer patients. The hypotheses were: Emotional distress, depression and depressive coping are associated with shorter survival; hope and active coping with longer survival. The study was based on a sample of n = 103 patients who were investigated post-diagnosis and before the beginning of primary treatment. Emotional distress and hope were assessed by clinical scales (self-reports and interviewer ratings), depression by the Depression Scale of von Zerssen, depressive coping and active coping by the Freiburg Questionnaire on Coping with illness by Muthny. At follow-up, which took place three to five years later, n = 74 patients had died, for n = 29 patients the survival data are censored. The prediction of the survival time was performed applying multivariate analyses (Kaplan-Meier-method, Cox-Regression), adjusting for biological risk factors (histological classification, stage of the disease, type and amount of treatment, Karnofsky performance status, age). Results were as follows: Active coping and hope were associated with longer survival, emotional distress, depression and depressive coping with shorter survival, respectively. These associations were found consistently across assessment methods. The predictive effects of coping and distress were statistically independent of the influence of the somatic risk factors. The best psychological predictor was the interviewer rating of active coping. Its predictive power equalled that of the Karnofsky performance status. However, there was evidence that the effects of the psychological factors varied somewhat in interaction with treatment modalities. The findings are discussed from a methodological perspective. Possible causal models and mechanisms are presented which could account for interactions of psychological measures and the course of the disease: Thus, it can be conceived that psychological effects were mediated by patients' compliance with medical treatment. In addition, it cannot be ruled out that psychological factors themselves were influenced by the physical status of the patients at the time of entry to the study.

Adaptation, Psychological↗
PubMed1997

Comparison of mean normal prothrombin time (PT) with PT of fresh normal pooled plasma or of a lyophilized control plasma (R82A) as denominator to express PT results: collaborative study of the International Federation of Clinical Chemistry. IFCC Working Group Standardization of Coagulation Tests.

The mean normal prothrombin time (MNPT) is currently recommended as the denominator term in the expression of PT ratio or International Normalized Ratio (INR) values. The PT of lyophilized normal control plasmas might also be used in calculating PT ratios, but the overall accuracy of this approach and its dependence on reagents and endpoint detectors have not been evaluated in detail. In an IFCC collaborative study involving 15 expert laboratories and 58 PT systems, the PT ratios of 30 apparently healthy subjects were expressed with the use of the MNPT, the PT of fresh normal pooled plasma (FNPP) obtained from the same apparently healthy subjects, or the PT of plasma R82A--a lyophilized normal pooled plasma prepared by the Verband der Deutschen Geräte-Hersteller for in-house calibration of a large amount of control plasma--as the denominator term. The total imprecision of the PT of plasma R82A averaged 2.16%. Mean PT ratios did not differ from 1.00 (mean 1.00, range 1.00-1.01) with the use of the MNPT as the denominator term. Mean PT ratios were > 1.00 with the FNPP-PT as the denominator term (1.02, 0.96-1.05), and differed according to endpoint detectors (P = 0.024). Mean PT ratios with plasma R82A-PT as the denominator term averaged 0.98 (range 0.91-1.06) with plain thromboplastins (n = 11), 1.02 (0.98-1.06) with combined thromboplastins (n = 3), and 0.93 (0.87-0.97) with recombinant thromboplastins (n = 2), but they differed according to the brand of plain or recombinant reagents (P = 0.00001), the endpoint detector (P < 0.0025), and the plasma citrate concentration (P < 0.0025). These findings underline the differences in the PT of lyophilized plasma R82A and the MNPT and PT of FNPP obtained from the same individuals and support the recommendation that the system-specific MNPT should be used as the ideal index of the normal PT in the calculation of INR values.

Female↗
PubMed1997

Interaction of Alkyl/Arylphosphonates, phosphonocarboxylates and diphosphonates with different anion transport systems in the proximal renal tubule.

Luminal and contraluminal stop-flow microperfusion was applied, and the apparent Ki values (mmol/l) against the luminal phosphate and the contraluminal p-aminohippurate (PAH), sulfate and dicarboxylate transport systems were evaluated. Luminal phosphate transporter: Among the 20 compounds tested only phosphonoformate (foscarnet), etidronate, and clodronate have a good affinity (app.Ki < 1 mmol/l), whereas the 2-naphthylphosphonates, phosphonoacetate, pamidronate, alendronate and aminomethanediphosphonates have a moderate affinity (app.Ki, 1.6-6.0 mmol/l). The other compounds tested had a low (app. Ki > 6 mmol/l) or no affinity. Contraluminal PAH transporter: The hydrophobic phenyl-, benzyl- or 2-naphthylphosphonates have good to moderate affinity, whereas the less hydrophobic alkylphosphonates, the phosphonocarboxylates (except 4-phosphonobutyrate) and all tested diphosphonates show no interaction. Sulfate transporter: 2-Naphthylmethylphosphonate and 2-naphthylmethyldifluorophosphonate have a good affinity (app.Ki </= 0.5 mmol/l), whereas Cl-F-methylphosphonate, 2OH-5NO2-benzyl-phosphonate, 2-naphthylhydroxymethylphosphonate, phosphonoacetate etidonate and clodronate have only a moderate affinity (app.Ki approximately 3 mmol/l). The other tested compounds have a low or no affinity. Dicarboxylate transporter: Among the tested compounds only 3-phosphonopropionate (app.Ki, 4.2 mmol/l) and 4 phosphonobutyrate (app.Ki, 7.0 mmol/l) interact with this transporter. Thus, we might conclude that in the submillimolar range only phosphonoformate (foscarnet), etidronate and clodronate inhibit luminal phosphate transport. As predictable from previous structure-activity studies for the contraluminal PAH, sulfate and dicarboxylate transporters the alkyl/arylphosphonates and the phosphonocarboxylates interact with these transporters according to their hydrophobicity and charge distribution. Among the seven diphosphonates tested, only etidronate and clodronate have a moderate affinity to the sulfate transporter, whereas the aminodiphosphonates have no (or low) affinity to any of the contraluminal anion transporters.

Animals↗
PubMed1997

[Ureteroscopy for ureteral calculi. 379 cases].

OBJECTIVE: We report the experience of a centre which treated symptomatic ureteric stones exclusively by ureteroscopy. METHODS: From 1987 to 1993, 379 patients underwent ureteroscopy for ureteric stones, corresponding to 231 men and 148 women, between the ages of 8 and 80 years. The stones were situated in the pelvic ureter in 78.9% of cases, iliac ureter in 15.8%, and lumbar ureter in 5.3% of cases. An 11 F or Gautier ureteroscope was used. The only intracorporeal lithotripsy method consisted of an ultrasound transducer. Finally, our department does not possess an extracorporeal lithotripsy apparatus allowing the treatment of ureteric stones. RESULTS: The stone was eliminated immediately in 288 patients (76%), the stone was pushed back into the renal cavities in 40 patients (1.5%) and partial failures (residual fragments) or complete failures were observed in 51 patients (13.5%). 13 ureteric perforations (3.43%), treated by means of a double J ureteric stent, and one surgically drained urinoma were observed. 13 false passages of the ureteric meatus had an uneventful course by drainage with a double J stent. CONCLUSION: Ureteroscopy remains an effective method for the treatment of ureteric stones. It is associated with a definite morbidity, probably higher in a University Centre in which future urologists are trained.

Adolescent↗