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Biomedical subjects

J Kirchner

Publications and source records attributed to J Kirchner.

At least 19 recordsLinked to original sources
PubMed1998

PGL-1, a predicted RNA-binding component of germ granules, is essential for fertility in C. elegans.

Germ cells are distinct from somatic cells in their immortality, totipotency, and ability to undergo meiosis. Candidates for components that guide the unique germline program are the distinctive granules observed in germ cells of many species. We show that a component of germ granules is essential for fertility in C. elegans and that its primary function is in germline proliferation. This role has been revealed by molecular and genetic analyses of pgl-1. PGL-1 is a predicted RNA-binding protein that is present on germ granules at all stages of development. Elimination of PGL-1 results in defective germ granules and sterility. Interestingly, PGL-1 function is required for fertility only at elevated temperatures, suggesting that germline development is inherently sensitive to temperature.

Alleles↗
PubMed1998

Brachytherapy with iridium-192 HDR to prevent from restenosis in peripheral arteries. An update.

The use of stents does not appreciably improve restenosis (usually resulting from intimal hyperplasia) as compared to percutaneous transluminal angioplasty (PTA) alone. The development of small-caliber probes for afterloading therapy in the biliary tract allowed us to use these for therapy in the vascular system. Using a special 9 F catheter, exact measurement of the length of the stented vascular segment and of the insertion length of the afterloading probe could be reproducibly performed. We used a Nucletron (Micro) Selectron HDR planning system version 10.10 for exact calculation, monitoring, and control of the afterloading procedure. Our source was iridium 192 (10 Ci) with a diameter of 1.1 mm. The program controls and monitors the insertion and removal of the iridium probe from the source into the special catheter through to the tip, and monitors the irradiation duration. The exposure time was around 200 seconds for a surface dose of 12 Gy. To date, a total of 40 patients have been treated with endovascular afterloading. All patients suffered from clinically relevant reocclusions or restenoses in stented vascular segments of the superficial femoral artery following successful PTA or laser treatment, within 6 to 8 months after the last therapy. In all patients it was possible to perform re-PTA treatment without remaining residual stenoses in the stented region. The additional time required as compared to PTA alone was approximately 45 minutes with most of this time spending for transportation between the cath lab and afterloading room. The follow-up period of the 40 patients ranged from 4 months to 71/2 years. In 33 patients, there was no deterioration of the clinical stage and no restenosis. One patient suffered from an acute thrombosis approximately 3 months after stent implantation, another patient had a stenosis 3 cm above the stented vascular segment 12 months after irradiation treatment. Follow-up examinations have revealed no evidence of nerve lesions following irradiation therapy. The tissue surrounding the artery showed no change following irradiation therapy, either in the CT, color-coded Doppler, endovascular ultrasonic scan or MRI. No complaints of discomfort were reported during or after irradiation. With the exceptions mentioned above, there was no evidence of any complications.

Aged↗
PubMed1998

CT findings in extensive tracheobronchial amyloidosis.

Primary pulmonary amyloidosis is a rare disorder that appears in three forms: tracheobronchial, nodular parenchymal, and diffuse parenchymal. We report the case of a 46-year-old women with extensive tracheobronchial amyloidosis which presented with a 2-year history of dyspnea and with signs of severe fixed obstruction in pulmonary function tests. Computed tomography of the thorax demonstrated marked thickening of the trachea and the central bronchial tree with substantial narrowing of the main, lobar, and segmental bronchi. Transbronchial specimen showed typical birefringence under polarizing microscope after staining with Congo Red. We did not find hints for systemic amyloidosis.

Amyloidosis↗
PubMed1998

[Diagnosis of pneumonia in long-term ventilated patients. Value of digital luminescence radiography in comparison with clinical and microbiological monitoring].

PURPOSE: Pulmonary infection is one of the most feared complications in patients receiving long-term ventilation. We evaluated prospectively the diagnostic value of daily bedside chest radiography performed as digital luminescence radiography (DLR) in comparison to clinical findings and quantitative microbial culture. MATERIAL AND METHODS: Prospective evaluation of daily bedside chest radiography (DLR) and clinical parameters such as blood count, body temperature, and microbiological monitoring (quantitative culturing, microscopy) of 20 patients receiving long-term ventilation was undertaken. Altogether 325 chest radiographs were evaluated. RESULTS: 96% of the routine radiographs showed abnormal findings. Nosocomial pneumonia was suspected in 31% of all 330 days of observation by means of clinical and microbiological findings. DLR showed correct findings in 80% of this days (right-positive interpretation); a false-positive interpretation was resulted in 16 radiographs. Most common finding in nosocomial pneumonia was an alveolar pattern with air bronchogram. Fever and leucocytosis often precede radiological evidence of pneumonia. CONCLUSION: Daily bedside chest radiography performed as DLR shows abnormal finding in a high percentage. Bedside chest radiograph is in accordance to clinical and microbiological finding of nosocomial pneumonia in 80%.

Adult↗
PubMed1998

[Pulmonary complications of induction therapy in acute myeloid leukemia in adults. Findings in chest x-rays and computer tomography].

UNLABELLED: To exclude pulmonary complications, 359 chest radiographs and 50 computed tomographs of the lung were performed in 95 patients suffering from acute myeloid leukemia. The radiological findings were registered, described and correlated with clinical findings in the present study on 2395 days of observation. RESULTS: In summary, 52 patients showed alterations of the lung. Pulmonary hyperhydration was seen in 21 cases, bacterial pneumonia was found in 18 cases, invasive pulmonary aspergillosis was documented in 14 cases, and 5 cases of severe haemorrhage were seen. An unexplained pulmonary edema in 13 patients with interstitial and alveolar infiltrates is considered to be a complication of treatment with cytosine- arabinoside. CONCLUSION: The results demonstrate that chest X- ray and computed tomography have a high impact in detection and treatment of pulmonary complications following intensive chemotherapy. We may expect the development of diffuse opacity following administration of cytosine-arabinoside in medium-sized doses.

Adolescent↗
PubMed1998

[Cavitating lung lesions in the course of ANCA-associated vasculitis: differential diagnostic aspects].

Antineutrophil cytoplasmatic antibodies (ANCA)-associated vasculitides (Wegener's granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome) show quite variable courses. Clinical features of the full blown generalized systemic vasculitis are usually found in the respiratory tract and the kidney. Pulmonary involvement of Wegener's granulomatosis shows commonly nodules and cavitations but also diffuse alveolar hemorrhage. We report the case of a 57 year-old man suffering from dyspnea, thoracal pain, arthralgia, purpura, scleritis and tinitus. Specimen of the kidney showed segmental glomerulosclerosis and tubulointerstitial nephritis. Because of the presence of cANCA Wegener's disease was assumed. Pulmonary infiltrates developed under immunosuppressive treatment with cyclophosphamid. As differential diagnosis of the pulmonary infiltrates, we considered invasive pulmonary aspergillosis as well as infiltrates due to Wegener's granulomatosis. In spite of maximal therapeutic management of patient died of respiratory and cardiovascular failure. The findings at autopsy showed distinct invasive pulmonary aspergillosis and perifocal hemorrhage.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1998

[Long-term follow-up and therapeutic control of a hepatic metastatic acinar cell carcinoma of the pancreas using FDG PET].

A 33 years old woman presented with cramp-like abdominal pain. Ultrasound examination revealed multiple lesions in the liver of hyper- and hypoechoic echogenicity which in accordance to subsequently performed computed tomography and dynamic hepatobiliary scintigraphy were considered to be a focal nodular hyperplasia (FNH). A severe increase of the serum lipase concentration, suspected to be an acute pancreatitis, was treated conservatively and led to a short improvement of symptoms. Some months later, a severe progression of the pain symptoms occurred, along with a measurable expansion of the abdominal circumference and palpable tumors of the liver. The dynamic hepatobiliary imaging and the static liver scan showed a decreased perfusion and function of the nodes as well as a reduced RES activity, respectively. A subsequently performed Positron Emission Tomography (PET) with F-18-Fluorodeoxyglucose (FDG) showed a massively increased glucose metabolism of the liver tumors. The histologic result of several biopsies of the tumors revealed metastases of an acinus cell carcinoma of the pancreas. Under systemic and local chemotherapy, a temporary remission could be obtained that was clearly detectable in a second FDG-PET. Nevertheless, during the further course of the disease, a progression occurred being detectable in an additional control PET-study by an increase in tumor size as well as in tumor glucose metabolism. The patient died in liver coma 15 months after the histologic diagnosis was obtained.

Adult↗
PubMed1997

Primary congenital pulmonary lymphangiectasia--a case report.

We report on a 22 year-old women with recurrent pleural effusions and shadowing of the right lower lobe, which was refractory to antibiotic treatment. Histologic examination (open lung biopsy) was interpretated as indicating an early stage of lymphangioleiomyomatosis. Because of progression of the pulmonary changes and development of a pericardial effusion in spite of antiestrogen treatment to achieve pharmacological castration, and in view of the atypical findings in high resolution computed tomography (lack of cysts) a second open lung biopsy was performed, confirming the diagnosis of pulmonary lymphangiectasia. The patient was given oral corticosteroids postoperatively and showed almost complete resolution of the pleural and pericardial effusions.

Adult↗
PubMed1997

[Radiotherapy of epicondylopathy of the humerus].

OBJECTIVE: To assess the efficacy of radiotherapy in alleviating pain at rest and on exercise in tennis elbow (humeral epicondylitis). PATIENTS AND METHODS: 45 elbow joints in 41 patients were radiated with a telecobalt unit in six sessions at a dose of 1.0 Gy each spread over 3 weeks. Indication for this treatment was pain in the elbow joint at rest, on pressure and on exercise. The patients were re-assessed after a mean follow-up period of 7.5 weeks. They were graded into one of five groups on the basis of their own assessment. Pain on exercise was determined by the Thompson hand-grip, chair test, forced extension and middle-finger stretch test. RESULTS: Satisfactory analgesia was achieved in 31 of 45 elbow joints (68.9%). About 50% of patients still had objectifiable pain on exercise. CONCLUSIONS: Radiotherapy is a highly efficacious means of pain alleviation in tennis elbow, but the results are better for pain at rest than on exercise. The Thompson hand-grip and chair test, positive in more than 90% of patients, proved to be reliable criteria to assess the indications for radiotherapy and its results.

Adult↗
PubMed1997

[Thrombosis of the inferior vena cava in Behçet disease].

Behçet's disease is considered to be a systemic process caused by a nonspecific vasculitis with a diversity of symptoms. It is defined by the coexistence of aphthous stomatitis, genital ulcerations, inflammatory conditions of the eye such as iritis and dermatological changes. Cardiovascular involvement includes both arteries and veins. We report an unusual case of thrombosis of the inferior vena cava with extensive collateral circulation of the superficial abdominal and paravertebral veins due to Behçet's disease diagnosed by phlebography and magnetic resonance imaging.

Behcet Syndrome↗
PubMed1997

Thymic stromal organization is regulated by the specificity of T cell receptor/major histocompatibility complex interactions.

The thymic architecture is normally compartmentalized into a central medulla surrounded by a peripheral cortical region. We investigated how compartmentalization of the thymic stroma is regulated using T cell receptor (TCR)-transgenic mouse models. Our studies show that the signals generated by TCR/peptide/major histocompatibility complex interactions regulate thymic stromal cell compartmentalization. In TCR-transgenic mice, normal stromal cell compartmentalization occurs when the transgenic TCR is expressed on a background that does not result in skewing toward either positive or negative selection. In models representing strong positive selection, the thymic stromal elements do not fully organize into a central medulla. Instead, small medullary foci are dispersed throughout the thymus with some regions residing directly under the capsule. The highest degree of disorganization in medullary epithelial regions is observed in TCR-transgenic mice that exhibit negative selection. Although the medullary foci lack central organization, the expression in these regions of CD80, CD86 and CD40, as well as the clustering of dendritic cells, is similar to that observed in medullae of wild-type mice. Thus, the organization of the medulla appears to occur in two stages: (1) small medullary epithelial regions that are dispersed in fetal thymi expand and associate with antigen-presenting cells, and (2) the expanded medullary foci organize into a central medullary compartment. Our data suggest a model in which this second stage of stromal cell organization is increasingly inhibited as the normal balance of TCR-mediated signals is skewed by higher-avidity interactions between thymocytes and antigen-presenting cells.

Animals↗
PubMed1997

[Necrotizing enterocolitis (NEC)].

Necrotizing enterocolitis is a serious abdominal disease in infants during the first 2 months of life. The earliest radiographic finding on frontal abdominal films is initially distension of the small bowel, secondly of the colon, and pneumatosis intestinalis. Pneumatosis intestinalis is not pathognomonic for necrotizing enterocolitis; it can occur throughout life in different abdominal diseases. It can be a serious prognostic sign for abdominal ileus, but it may also occur in non-critically ill patients. Radiographic diagnosis in childhood is achieved with a frontal film of the abdomen in the prone position, and to detect a possible perforation, a left lateral abdominal decubitus exposure is necessary. Sonography and duplex sonography are helpful in evaluating progressive changes, the clinical course and the differential diagnosis.

Diagnosis, Differential↗
PubMed1997

Role of quantitative cultures and microscopic examinations of endotracheal aspirates in the diagnosis of pulmonary infections in ventilated patients.

Endotracheal aspirates (EA) from 20 intubated patients in a surgical intensive care unit (mean ventilation time/patient = 16.5 days) were investigated serially by performing quantitative cultures using growth of 10(5) cfu/mL as a cut-off point. Microscopic examinations were made using Giemsa's stain for polymorphonuclear neutrophils (PMN). The spectrum of pathogens encountered was determined and compared with clinical data to distinguish colonization from infection of the lower respiratory tract. Out of 301 EA cultures, 156 (51.8%) were positive and 145 (48.2%) were below the cut-off point. Counts of PMN were significantly higher in samples which gave positive cultures. Seventy-five different bacterial strains were isolated (64% were Gram-negative bacilli). Seventeen patients (85%) were colonized with Gram-negative bacteria. Nine patients (45%) developed nosocomial pneumonia (NP), five (25%) had no signs of pneumonia, and six (30%) had an uncertain status. Main causative agents for NP were Pseudomonas aeruginosa, Enterobacteriaceae and Staphylococcus aureus. Quantitative EA cultures had a sensitivity of 81.5%, a specificity of 64.8%, a positive predictive value of 55% and a negative predictive value of 87%. Our results suggest that EA quantitative cultures (cut-off value 10(5) cfu/mL), species identification and microscopic examination of EA may help to differentiate tracheobronchial colonization and infection, especially when bronchoscopic techniques are not available.

Adult↗
PubMed1997

[The computed tomographic determination of intra-abdominal fat volume by single-layer measurement].

PURPOSE: Several studies emphasised the importance of the relationship between intra-abdominal and total body adipose tissue as a risk factor for the development of metabolic or cardiovascular diseases. Therefore, the aim of the present study was to examine whether a single-scan computed tomography is able to determine the whole intra-abdominal fat volume with high accuracy and reproducibility. MATERIALS AND METHODS: Regions of interests (ROIs) were drawn manually for measuring intra-abdominal fat in 51 unsuspicious abdominal CT. RESULTS: The sexual differentiation of adipose tissue already described in a lot of studies could be confirmed in this study. Fat still predominates in females in lower half of the body (gynecoid obesity). In men it predominates in the upper half (android obesity). Significant correlation concerning measuring the whole intra-abdominal fat volume could be found in L1-level in women (r = 0.992) and in L2-level in men (r = 0.992). Measurement of a single scan enables us to assess whole intra-abdominal fat volume due to a special formula. CONCLUSION: The determination of intra-abdominal fat measured by a single-scan computed tomography is a procedure associated with high accuracy and reproducibility.

Adipose Tissue↗
PubMed1997

Detection of normal mediastinal lymph nodes by ultrasonography.

PURPOSE: The detection by US (in contrast to CT) of lymph nodes of any size in the mediastinum is usually considered to be a pathological finding. The aim of this study was to find out whether it was possible to detect normal lymph nodes by high-resolution mediastinal US. MATERIAL AND METHODS: Six different mediastinal regions in 80 healthy asymptomatic volunteers and in 20 human cadavers were examined by means of US (with colour Doppler imaging) to assess US access to the respective regions and to demonstrate the number and size of detectable lymph nodes. All the cadaveric lymph nodes that were detected were examined histologically to exclude inflammatory or malignant infiltration. RESULTS: In almost all subjects, we obtained US access to the supra-aortic (100%), paratracheal (95%), prevascular (99%), and pericardial (98%) regions, and to the aorticopulmonary window (98%). US access to the subcarinal region was more difficult (75%). In the healthy subjects, lymph nodes were detected in the paratracheal region (in 35% of these subjects, mean lymph-node diameter 12 x 7 mm), in the aorticopulmonary window (45%, 14 x 8 mm), and in the subcarinal region (13%, 13 x 7 mm). In the cadavers, histologically normal lymph nodes were detected frequently in the paratracheal region (85%, mean size 11 x 6 mm) and in the aorticopulmonary window (90%, 11 x 5 mm). CONCLUSION: These results indicate that normal lymph nodes (and not only pathological lymph nodes) can be demonstrated by high-resolution mediastinal US.

Adult↗
PubMed1997

Comparison of remifentanil and fentanyl in patients undergoing craniotomy for supratentorial space-occupying lesions.

BACKGROUND: Remifentanil hydrochloride is an ultra-short-acting, esterase-metabolized mu-opioid receptor agonist. This study compared the use of remifentanil or fentanyl during elective supratentorial craniotomy for space-occupying lesions. METHODS: Sixty-three adults gave written informed consent for this prospective, randomized, double-blind, multiple-center trial. Anesthesia was induced with thiopental, pancuronium, nitrous oxide/oxygen, and fentanyl (n = 32; 2 micrograms.kg.-1. min-1) or remifentanil (n = 31; 1 mu.kg-1.min-1). After tracheal intubation, infusion rates were reduced to 0.03 microgram.kg-1.min-1 (fentanyl) or 0.2 microgram.kg-1.min-1 (remifentanil) and then adjusted to maintain anesthesia and stable hemodynamics. Isoflurane was given only after specified infusion rate increases had occurred. At the time of the first burr hole, intracranial pressure was measured in a subset of patients. At bone flap replacement either saline (fentanyl group) or remifentanil (approximately 0.2 microgram.kg-1.min-1) were infused until dressing completion. Hemodynamics and time to recovery were monitored for 60 min. Analgesic requirements and nausea and vomiting were observed for 24 h. Neurological examinations were performed before operation and on postoperative days 1 and 7. RESULTS: Induction hemodynamics were similar. Systolic blood pressure was greater in the patients receiving fentanyl after tracheal intubation (fentanyl = 127 +/- 18 mmHg; remifentanil = 113 +/- 18 mmHg; P = 0.004). Intracranial pressure (fentanyl = 14 +/- 13 mmHg; remifentanil = 13 +/- 10 mmHg) and cerebral perfusion pressure (fentanyl = 76 +/- 19 mmHg; remifentanil = 78 +/- 14 mmHg) were similar. Isoflurane use was greater in the patients who received fentanyl. Median time to tracheal extubation was similar (fentanyl = 4 min: range = -1 to 40 min; remifentanil = 5 min: range = 1 to 15 min). Seven patients receiving fentanyl and none receiving remifentanil required naloxone. Postoperative systolic blood pressure was greater (fentanyl = 134 +/- 16 mmHg; remifentanil = 147 +/- 15 mmHg; P = 0.001) and analgesics were required earlier in patients receiving remifentanil. Incidences of nausea and vomiting were similar. CONCLUSIONS: Remifentanil appears to be a reasonable alternative to fentanyl during elective supratentorial craniotomy.

Adult↗
PubMed1997

Balloon dacryocystoplasty: indications and contraindications.

PURPOSE: To define the indications and contraindications for balloon dacryocystoplasty. MATERIALS AND METHODS: Eighty-five patients with severe epiphora due to partial (n = 47) or complete (n = 38) obstruction of the nasolacrimal duct (NLD) were treated with balloon dacryocystoplasty (DCP). Steerable micro-guide wires with flexible tips were used. Success rates of DCP were evaluated clinically and dacryocystographically during the acute phase and at 6- and 12-month follow-up. Failures and recurrences were correlated with clinical and dacryocystographic indications for treatment. RESULTS: Recanalization was successful in 35 (92%) of 38 patients with isolated focal stenoses (n = 20) or short-distance occlusions (n = 18) of the NLD. Among all 85 patients, recanalization was successful in 25 patients (66%) with complete and 37 patients (79%) with partial obstructions. In the absence of the main predictors for recurrent obstructions (ie, active inflammation, filling defects due to calculi, long-distance occlusions, and posttraumatic lesions), 12-month patency rates were 89% (17 of 19 focal stenoses) and 94% (15 of 16 focal occlusions). Otherwise, reobstruction rate was 46% (12 of 26 cases). CONCLUSION: Balloon dacryocystoplasty is successful only in select cases. To achieve results comparable to those of operative treatment, the indication should be limited to patients with circumscribed focal stenoses or occlusions of the NLD. Active dacryocystitis, dacryocystolithiasis, and posttraumatic lesions are the main contraindications.

Catheterization↗