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J Lange

Publications and source records attributed to J Lange.

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

Detection of the ATP-dependent nonmitochondrial calcium store in a cell surface-derived vesicle fraction from isolated rat hepatocytes.

In preceding studies, the IP3-sensitive Ca2+ store of the hamster insulinoma cell line, HIT, was detected in cell surface protrusions such as microvilli and related membrane structures [Lange, K., and Brandt, U. (1993) FEBS Lett. 320, 183-188; and (1993) FEBS Lett. 325, 205-209]. In this study, these experiments were extended on rat hepatocytes. We used the previously described shearing technique for isolating cell surface-derived vesicle fractions from freshly isolated and 48-h-cultured rat hepatocytes. As shown by Western blot analysis, these vesicles contained the hepatocyte-specific glucose transporter, GluT2, and actin, which are both typical microvillar components. Scanning electron microscopy revealed that a spherical vesicle population of uniform size (about 1 microm in diameter) originates from the hepatocyte microvilli. This vesicle fraction exhibited ATP-dependent and thapsigargin-sensitive Ca2+ storage activity with properties identical to those of the known microsomal systems and of HIT cell surface-derived vesicles, except that the ATP-dependent Ca2+ pool was insensitive to IP3. Like HIT surface vesicles, hepatocyte surface vesicles rapidly took up ATP via a 4,4'-diisocyanostilbene-2,2'-disulfonic acid (DIDS)-sensitive anion pathway. Inhibition of ATP influx into the vesicles by DIDS also completely inhibited ATP-dependent Ca2+ storage. Moreover, determination of efflux kinetics of Ca2+ from passively (in the absence of ATP) loaded vesicles revealed a La(3+)-sensitive but IP3-independent Ca2+ pathway which rapidly equilibrated intravesicular free Ca2+ with the external medium. Permeabilization of the vesicles with saponin (0.005%) opened an additional efflux pathway for Ca2+ which is not La(3+)-sensitive. However, saponin treatment of vesicles preloaded with Ca2+ in the presence of ATP did not affect the thapsigargin-sensitive vesicular Ca2+ store but only released a small portion (about 20%) of the vesicular Ca2+ that is not part of the thapsigargin-sensitive Ca2+ pool. Also, the size of the saponin-releasable Ca2+ pool was not affected by depletion of the thapsigargin-sensitive Ca2+ store. These findings indicate that hepatocyte surface vesicles are readily permeable for Ca2+ and ATP via cation and anion pathways. Consequently, Ca2+ storage into these vesicles does not occur by concentrative Ca2+ pumping but rather appears to be due to an internal, ATP-dependent mechanism of Ca2+ sequestration. The presented data are in accord with the previously reported colocalization of the ATP-dependent Ca2+ store and its functionally coupled, store-regulated Ca2+ influx pathway in special cell surface organelles, the microvilli.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1996

Detection of iron-deficiency anemia in hospitalized patients by zinc protoporphyrin.

The diagnostic value of zinc protoporphyrin (ZPP) as an indicator of iron-deficient anemia (IDA) in hospitalized patients is assessed in this study. ZPP was measured using an AVIV hematofluorometer with a coefficient of variation (CV) less than 5% and a recovery of greater than 97%. A reference range of 53-70 mu mol/mol heme was determined for ZPP in non-anemic patients in a hospital population. Hospitalized patients (221) with low hemoglobin (< 120 g/l) were evaluated for their iron status. ZPP and other anemia tests were performed. Macrocytic patients with mean corpuscular volume (MCV) greater than 98 fl) were excluded from the study. Seventy-four microcytic patients (MCV < 80 fl) were determined as having IDA according to a diagnostic algorithm. A distribution study of these microcytic patients showed that there was a significant overlap of values between the IDA and non-IDA patients for all serum anemia tests. A receiver-operator curve analysis revealed that ZPP has a relatively high degree of diagnostic efficiency better than iron and ferritin for this patient population. At a cutoff value > 170 mu mol/mol heme, ZPP has a sensitivity of 93% and a specificity of 90%. In addition, ZPP is also elevated in normocytic patients (MCV = 80-98 fl) with low ferritin values, who may have iron depletion. From these data, it is proposed that ZPP may be used as a screening tool for IDA in hospitalized patients.

Adult↗
PubMed1996

Determination of carbonyl compounds in exhaust gas by using a modified DNPH-method.

The determination of carbonyl compounds in gaseous samples is usually accomplished by enrichment methods, in which 2,4-dinitrophenyl-hydrazine (DNPH) as a derivatization reagent has become established to a large extent. However, the conventional methods of DNPH-impingers and of DNPH-cartridges are applicable to emission measurements in a limited way only, depending on the NO(2)-concentration in the exhaust gas. It could be proved that DNPH-derivatives, as well as DNPH, are also decomposed by NO(2) at a different speed, in which the hydrazones of unsaturated carbonyl compounds are probably more sensitive than those of the saturated carbonyl compounds. In view of this fact, the collecting methods had to be modified to avoid losses with the enrichment. The analysis of the compounds is carried out by HPLC with an effective gradient-system which is able to separate and detect the carbonyl compounds in exhaust gas within 16 min. Furthermore, a simple working-up procedure is presented which facilitates a parallel analysis by GC.

Journal Article↗
PubMed1996

Proteolytic processing of class IV chitinase in the compatible interaction of bean roots with Fusarium solani.

Three chitinase isoenzymes, PvChiE, PvChiF, and PvChiG (molecular masses 29, 28, 27 kD, respectively), were purified from bean (Phaseolus vulgaris L. cv Saxa) roots infected with the fungal pathogen Fusarium solani f. sp. phaseoli, and their amino acid sequence was partially determined. All sequences from all three isoenzymes exactly matched deduced amino acid sequences of the bean class IV chitinase PvChi4, formerly called PR4. The N terminus of PvChif mapped to the hinge region, and the N terminus of PvChiG mapped to the catalytic domain of PvChi4. The N terminus of PvChiE was blocked. The appearance of PvChiE, PvChiF, and PvChiG correlated with an increase in protease activity in infected roots, and they could be generated in vitro by mixing extracts with high protease activity with extracts containing high amounts of PvChi4. Extracts from infected roots prepared in the presence of protease inhibitors also contained the processed forms of PvChi4, indicating that processing occurred in planta and not as an artifact of extraction. Processing of PvChi4 was not detected in incompatible interactions with a nonhost strain of F. solani and in symbiotic interactions with Glomus mosseae, and thus may be important only in compatible interactions with F. solani.

Amino Acid Sequence↗
PubMed1996

[Technique and results of laparoscopic rectum resection].

The general principles of oncologic operations for colorectal cancer are the same for both open and laparoscopic surgery. Isolation of the tumor by occlusion of the intestinal lumen, early blockage of venous outflow, complete resection of the lymph node bearing mesenterium, high ligation of the artery and prevention of tumor cell dissemination during extirpation of the specimen are the most important factors. We present our technique for laparoscopic abdominoperineal resection, which fulfills the above mentioned criteria. From June 1993 to October 1994 we operated on 19 patients (median age 68 [47-91] years; male/female ratio 10/9). Laparoscopic abdominoperineal resection of the rectum was palliative in 3 patients and curative in 16. Tumors were located 3 (1-8) cm from the anal verge. In 3 patients the operation was converted to open surgery. Intraoperative complications were encountered in 3 patients. Median operation time was 300 (200-400) minutes and postoperative morbidity 8/19 (42%) leading to reoperation in one patient. 30-day mortality was nil. Three patients died 5, 8, and 14 months postoperatively due to metastatic disease (all 3 after initial palliation). One patient had local recurrence and liver metastasis and died 14 months after operation. Another patient died from liver metastases. In one patient a single liver metastasis was successfully removed. 14 patients were tumor-free after a median follow-up of 10 (3-14) months. There was no implantation metastasis on a trocar site. Laparoscopic abdominoperineal resection of the rectum is feasible and the results are comparable with those of open surgery. Local recurrence rate and incidence of liver metastases are comparable with open surgery after this short follow-up. However, 5-year survival is needed to judge the oncological radicality of laparoscopic abdominoperineal resection of the rectum.

Adenocarcinoma↗
PubMed1995

[Surgical and nuclear medicine treatment of hyperthyroidism].

Radioiodine and surgery are the therapeutic tools of choice for the definitive treatment of patients suffering from hyperthyroidism. The decision on the therapy to choose for an individual patient will depend on several different factors: etiology of the hyperthyroidism, size of the goiter, age and general medical considerations, availability of radioiodine therapy or of an experienced endocrine surgeon, and the patient's own preferences. It is important for the general practitioner attending and advising a patient to have a basic knowledge of both therapeutic modalities. An overview of indications, results and risks of the radioiodine and surgical therapy is presented.

Antithyroid Agents↗
PubMed1995

Distinct changes in HIV type 1 RNA versus p24 antigen levels in serum during short-term zidovudine therapy in asymptomatic individuals with and without progression to AIDS.

Serum HIV-1 RNA and p24 antigen levels were examined in 28 seropositive asymptomatic individuals participating in a trial on the efficacy of zidovudine. Sixteen individuals remained asymptomatic until 4 years after the onset of the trial, whereas 12 individuals were diagnosed with an AIDS-defining event. The serum HIV-1 RNA load and p24 antigen levels were determined before the onset of therapy and during the first 8 weeks of therapy to establish whether the patterns of change were predictive of clinical outcome. Among the 28 participants 43% had measurable pretreatment concentrations of p24 antigen. Initiation of zidovudine therapy was followed by a similar decline of p24 antigen levels in nonprogressors as well as progressors and, therefore, these groups could not be distinguished on the basis of this parameter. HIV-1 RNA was detected in the pretreatment samples of 82% of the individuals and could be detected in p24 antigen-positive as well as p24 antigen-negative individuals. Similar changes in HIV-1 RNA load during zidovudine therapy were observed in p24 antigen-positive and -negative individuals. Analysis of the HIV-1 RNA response according to clinical outcome demonstrated that HIV-1 RNA copy numbers had declined significantly after 4 weeks of therapy in both nonprogressors and progressors, but the decline in RNA load was much stronger in the nonprogressors. Our data show that the HIV-1 RNA load in serum can be used to monitor the response to antiviral therapy in p24 antigen-positive as well as -negative individuals. Posttreatment changes in p24 antigen levels are not indicative for clinical outcome, whereas RNA copy numbers are.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1995

Colonization of Transgenic Tobacco Constitutively Expressing Pathogenesis-Related Proteins by the Vesicular-Arbuscular Mycorrhizal Fungus Glomus mosseae.

We studied the effect of constitutive expression of pathogenesis-related proteins (PRs) in tobacco plants on vesicular-arbuscular mycorrhiza. Tobacco lines genetically transformed to express various PRs constitutively under the control of the cauliflower mosaic virus 35S promoter of tobacco were examined. Immunoblot analysis and activity measurements demonstrated high levels of expression of the PRs in the root systems of the plants. Constitutive expression of the following acidic isoforms of tobacco PRs did not affect the time course or the final level of colonization by the vesicular-arbuscular mycorrhizal fungus Glomus mosseae: PR-1a, PR-3 (=PR-Q), PR-Q(prm1), PR-4, and PR-5. Similarly, constitutive expression of an acidic cucumber chitinase, of a basic tobacco chitinase with and without its vacuolar targeting peptide, of a basic (beta)-1,3-glucanase, and of combinations of PR-Q and PR-Q(prm1) or basic chitinase and basic (beta)-1,3-glucanase did not affect colonization by the mycorrhizal fungus. A delay of colonization by G. mosseae was observed in tobacco plants constitutively expressing the acidic isoform of tobacco PR-2, a protein with (beta)-1,3-glucanase activity.

Journal Article↗
PubMed1995

Combination antiretroviral therapy. Back to the future.

HIV causes chronic infection and is associated with persistent viral replication and a high viral mutation rate. It is an illusion to think that monotherapy with any antiretroviral agent will have a major and lasting impact on this disease. Monotherapy with antitubercular agents led to dramatic improvements in treatment, but the development of drug resistance meant that these improvements were of only short duration, and hence it was concluded that drugs should be combined. The response to the limited efficacy of nucleoside analogue monotherapy in HIV infection has in many instances been the stance that 'currently available antiretrovirals are no good; it is better not to treat'. In addition, regulatory insistence on clinical end-points has also hampered antiretroviral drug development. It is implied that antiretrovirals must be tested in populations with fairly advanced HIV infection, in whom the least success may be expected. The regulatory bind has also resulted in artificial and counterproductive treatment guidelines. Common sense and experience in infectious diseases dictate that treatment should hit hard and early. No study published thus far undermines the concept that early therapy is better than late therapy or that a tolerable combination of drugs with additive or synergistic anti-HIV activity is better than nucleoside monotherapy. Promising data have been generated in trials on combinations of zidovudine plus didanosine or zalcitabine; a combination of zidovudine and lamivudine (3TC) may be even more promising.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1995

[Educational opportunities in minimally invasive surgery].

Since minimally invasive surgery makes high demands on the skill, concentration and endurance of the surgeon, requisite training in this operating technique is of overriding importance. Basic training on pelvitrainers serves to enable the participant to become acquainted with the instruments and the video technique and to gain experience in handling the camera. A realistic simulation of intraoperative situations is not possible. With pulsatile organ perfusion (POP) nearly all abdominal, thoracic, vascular, urological and gynecological surgical procedures, as well as the encountered complications, can be imitated, widely replacing the need for animal experiments. Complex operations which are bound to anatomical structures, have to be practised on anaesthetized animals, as before.

Animals↗
PubMed1995

[The value of laparoscopy in diagnosis and therapy of the traumatized abdomen].

The prognosis of abdominal trauma depends in most cases not only on the extent of existing injuries but also on prompt therapy. Thus, diagnostic measures have to clarify rapidly and accurately whether laparotomy has to be performed or not. Difficulties in decision for the surgeon arise especially in cases of abdominal trauma where diagnostic imaging (ultrasonography, CT scan) does not lead to clearcut results. From 1st June, 91 to 30th November, 93 we performed diagnostic laparoscopy in 18 cases of abdominal trauma. In 4 patients no injuries were discovered and 5 patients had negligible injuries so that no therapy was necessary. In 4 cases the detected injuries were managed laparoscopically, whilst the remaining 5 patients had to be laparotomied. Of the 11 patients who would normally have been laparotomied as a primary measure, laparotomy was avoided in 5 cases by performing a laparoscopy (45%). On the other hand, we detected injuries on laparoscopy in 3 of the 7 patients who would not have been laparotomied on the basis of the results of the prelaparoscopic investigations. In 2 of these patients the additional injuries would have led to later complications, which were avoided by timely laparotomy following laparoscopic diagnosis. In our opinion laparoscopy is not a substitute for proven diagnostic measures such as ultrasonography or CT scan. However, it is valuable extension of diagnostic and therapeutic methods on abdominal trauma.

Abdominal Injuries↗
PubMed1995

[Integration, organization and results of ambulatory surgery in a central hospital].

Principally driven by economic necessity, i.e. reduction of health care personnel and beds, a significant increase in number of major operations for in-patients and a general attempt to reduce costs, a day-surgery unit was established for the Surgical Department at the Kantonsspital St. Gallen. Several requirements have to be met: Standardized techniques have to be applied by experienced surgeons and strict selection criteria for patients as well as intensive preoperative patient information and consenting have to be observed. During a two year period (September 1992 to August 1994) 389 patients were evaluated for ambulatory surgery. 106 patients (27.2%) had to be rejected for social, medical and financial reasons. Eventually operations were carried out on 283 patients. The majority of procedures performed were for herniae (37.8%) followed by varicose vein-surgery (22.6%). Only 8 patients had to be admitted for observation as in-patients, this was mainly due to difficulties in postoperative mobilisation and micturition problems. To monitor our quality of care, questionnaires were sent to patients and general practitioners (GP's). 98% of patients were satisfied with the preoperative information standards. Difficulties in adapting to a postoperative daily routine was stated by 13% of patients. 80% of patients would again opt for surgery on a day-care basis in future. 81% of GP's reported a positive benefit for their patients from ambulatory surgery. All GP's were prepared to undertake preoperative patient evaluation according to standardized selection criteria. A significant reduction in costs can be expected. With the current health-insurance system this is unfortunately achieved with an increased financial burdening for the patient.

Ambulatory Surgical Procedures↗
PubMed1994

[Can one dispense with preoperative cholangiography in connection with laparoscopic cholecystectomy?].

Since the introduction of laparoscopic cholecystectomy as method of choice for the treatment of gallstone disease, many authors have proposed a preoperative intravenous cholangiogram as an alternative to routine intraoperative cholangiography. To assess the value of intravenous cholangiography we performed a prospective randomized study with 100 patients undergoing cholecystectomy for gallstone disease. Patients with predefined criteria indicating possible choledocholithiasis were excluded. In none of the 50 performed i.v.-cholangiograms was evidence of a stone in the common bile duct or an anatomic variation of the biliary tract found. There was no significant difference in regard to intra- and postoperative complications between the group with preoperative cholangiography and the group without intravenous cholangiogram. We conclude that there is no significant advantage in performing routine preoperative intravenous cholangiography, and recommend the selective use of intraoperative cholangiography.

Cholangiography↗
PubMed1994

Bicyclic [b]-heteroannulated pyridazine derivatives--II. Structure-activity relationships in the 6-aryltriazolo-[4,3-b]pyridazine ligands of the benzodiazepine receptor.

Electronic parameters (molecular electrostatic potential MEP, charge distribution on the nitrogen atoms, dipole moment mu and ionization potential IP) were calculated by semiempirical quantum chemistry methods for 2 sets (X = H and m-CF3, the syn- and anti-rotamers of the latter being considered separately) of the 6-aryl-3-substituted-triazolo[4,3-b]pyridazine ligands of the benzodiazepine receptors (Figure 1; for X and Y c.f. Table 1). The calculations located the deepest MEP minimum near the = N-N = fragment of the triazole ring (Figure 2). Activity of the investigated compounds (1 microM), expressed as % inhibition of in vitro 3H-diazepam (1.5 nM) binding, revealed a significant dependence on IP, which combined in correlation studies with the hydrophobic constants pi X and pi Y and the Swain-Lupton field constant FY gave a 100% explanation of variance (Equations 1-3). However, extrapolation pointed to a compound with excessive hydrophobicity. The dipole moment orientation, roughly consistent with the C(6)-aryl main molecular axis, was considered as another factor controlling the docking of the investigated triazolopyridazine ligands to the benzodiazepine receptor (Figure 3). A model of the triazolopyridazine-benzodiazepine receptor interaction was proposed (Figure 4).

Animals↗