Biomedical subjects

A Bickel

Publications and source records attributed to A Bickel.

At least 37 records · Page 2Linked to original sources

PubMed1999

The impact of patient delay and physician delay on the outcome of laparoscopic cholecystectomy for acute cholecystitis.

BACKGROUND: Laparoscopic cholecystectomy is now used in the management of acute cholecystitis. Under these circumstances unfavorable conditions may result in conversion and complications. Information about these conditions may help in planning the laparoscopic approach or in proceeding directly to open cholecystectomy. This study was initiated to evaluate perioperative factors associated with conversion and complications of laparoscopic cholecystectomy in acute cholecystitis. Special attention was paid to the duration of complaints until surgery, to the delay on the part of the patient, and to the delay on the part of the physician. METHODS: Between January 1994 and December 1997, we attempted to perform laparoscopic cholecystectomy on 348 patients with acute cholecystitis. All perioperative data were collected on standardized forms. RESULTS: There were 182 cases (52%) of acute uncomplicated cholecystitis, 90 (26%) of gangrenous cholecystitis, 33 of hydrops (9.5%), and 43 of empyema of the gallbladder (12.5%). Seventy six patients (22%) needed conversion to open cholecystectomy and complications occurred in 57 cases. Advanced cholecystitis was associated with significant patient delay (P = 0.01), and it had a significantly higher conversion rate (39%) compared with early cholecystitis (14.5%); (P <0.00001). Conversion rates were also associated with male gender (P = 0.0017), a history of biliary disease (P = 0.0085), and a patient delay of >48 hours (P = 0.028). The total and infectious complication rates were associated with an age older than 60 years (P = 0.023 and 0.007, respectively) and male gender (P = 0.026 and 0.014, respectively). CONCLUSIONS: In acute cholecystitis, patient delay is associated with a high conversion rate. Early timing of laparoscopic cholecystectomy tends to reduce the conversion rate, as well as the total and the infectious complication rates. Male gender, a history of biliary disease, and advanced cholecystitis are associated with conversion. Male and older patients are associated with a high total and infectious complication rates.

Acute Disease↗

PubMed1999

Laparoscopic repair of paracolostomy hernia.

Paracolostomy hernia is a common complication of stoma creation. Operative repair is indicated in about 15% of cases, through several surgical approaches. We describe a laparoscopic technique used to repair a large symptomatic paracolostomy hernia in a 69-year-old woman almost 20 years after abdominoperineal resection. The laparoscopic approach to such a hernia is feasible, safe, and logical, as it combines the advantages of mesh reinforcement with those of endoscopic repair.

Aged↗

PubMed1999

Laparoscopic splenopexy of a wandering spleen.

A laparoscopic technique for splenopexy of a wandering spleen using an absorbable mesh in an adult woman is described for the first time. This patient was referred to surgery because of recurrent biliary colic secondary to cholecystolithiasis. The wandering spleen had been diagnosed at least 4 years earlier, but a conservative approach had been adopted for a symptomless patient. Laparoscopic cholecystectomy was performed concomitantly with splenopexy. Laparoscopic splenopexy seems a feasible and safe procedure, especially when performed by experienced laparoscopic surgeons.

Adult↗

PubMed1999

Use of endoscopic trocar-cannula for chest drain insertion in trauma patients and others.

BACKGROUND: The insertion of a chest drain into the pleural space is a common procedure used for treatment in various intrathoracic abnormalities. Recently, a new technique for chest-tube insertion for pleural cavity drainage, using the disposable endoscopic trocar-cannula, was described for the treatment of some pathologic conditions. METHODS: In a prospective study, we used this technique in the treatment of patients with chest trauma, spontaneous and iatrogenic pneumothorax, and various kinds of pleural effusion. RESULTS: One hundred twelve patients were treated by using the endoscopic trocar-cannula for tube insertion into the pleural cavity. Among them, 39 patients were treated after blunt and penetrating chest trauma. Most cannulae were of 10 to 11 mm in diameter, which enabled the insertion of large-bore drain tubes. In five trauma patients, chest-tube insertion was done successfully without antecedent chest x-ray films. The complication rate was 0.89% for intrapulmonary positioning of a chest tube in a patient who had previous ipsilateral thoracic surgery. CONCLUSION: The use of endoscopic trocar-cannulae for chest-tube insertion is a safe, simple, and effective technique for management of trauma and other diverse intrathoracic abnormalities. Its use outside the hospital should be further studied.

Adolescent↗

PubMed1998

Laparoscopic approach to hydatid liver cysts. Is it logical? Physical, experimental, and practical aspects.

BACKGROUND: In recent years attempts have been made to treat hydatid liver cysts laparoscopically. The purpose of this study was to evaluate different aspects of this approach and to examine whether a reasonable model could be developed. METHODS: Three different subjects were analyzed. In the first, physical aspects related to transmembrane pressures were analyzed to demonstrate that evacuation of the cyst under pneumoperitoneum does not carry increased risk of spillage, and may even offer an advantage when the proper technique is used. In the second subject, an isolated liver model of a goat was used to study several techniques for evacuating hydatid cysts without spillage. This was tested qualitatively by demonstrating scolices in the fluid medium around the isolated liver after surgical manipulations. In the third subject, the implication of the technique was evaluated in human patients. RESULTS: According to basic physical assumptions, the following conclusions were reached: (1) The increase in intracystic pressure is equal to or less than the increase in intraperitoneal pressure after pneumoperitoneum. (2) Aspiration of parasitic cysts by laparoscopic needle through a large cannula under "vacuum" or by sealing the cannula and adhering it to the liver by cyanoacrylate or fibrin glue was found to be very safe. Simple needle aspiration failed to prevent spillage. (3) A new transparent cannula 18 mm in diameter with a beveled tip was designed that enables good accessibility to liver cysts and safe evacuation even of huge and complex cysts. CONCLUSIONS: The novel technique to manage hydatid liver cysts, described in the study, is feasible, sensible, and safe. The isolated goat liver containing hydatid cysts can be used as a reliable animal model to test new techniques in the future.

Animals↗

PubMed1998

Effects of antihyperalgesic drugs on experimentally induced hyperalgesia in man.

In a double-blind, cross-over study, ibuprofen (600 mg), a peripherally-acting selective kappa-opioid receptor agonist (7.5 mg), or placebo were given orally in experiments on healthy volunteers 1 h before assessment of pain thresholds to radiant heat and of pain ratings to controlled mechanical impact stimuli. Mechanical and thermal hyperalgesia had been induced 24 h before by irradiating skin patches on the ventral side of the upper leg. UVB irradiation induced mechanical and thermal hyperalgesia at radiation dosages of three times the minimal erythema dose. UVA irradiation resulted in an immediate erythema and a delayed tanning of the skin, however, no hyperalgesia was observed. For comparison another model of mechanical hyperalgesia was applied in the same experiments which has been previously proven sensitive to non-steroidal anti-inflammatory drugs (NSAIDs). In this model hyperalgesia was assessed, which develops during repetitive pinching of skin folds (pinch model). Ibuprofen significantly diminished heat and mechanical hyperalgesia induced by UVB, but had no effect on pain responses obtained from untreated skin. It also had an antihyperalgesic effect in the pinch stimulus paradigm. In contrast, the kappa-agonist showed no antihyperalgesic efficacy in the chosen models. It is concluded that the UVB model, as the pinch model, is suitable for establishing antihyperalgesic effects of NSAIDs, but probably not of kappa-receptor agonists, in healthy human volunteers. Compared to the pinch stimulus model, the UVB model offers additional advantages: (a) drugs may be tested after induction of the skin trauma by UV and this situation is more similar to the clinical use of antihyperalgesic drugs. (b) Since mechanical and thermal hyperalgesia is induced by UVB, drug effects can be tested upon both forms of hyperalgesia.

Adult↗

PubMed1998

Laparoscopic cholecystectomy for acute cholecystitis performed by residents in surgery: a risk factor for conversion to open laparotomy?

Recent observations point to a seemingly high conversion rate to laparotomy in cases of laparoscopic operations for acute cholecystitis that are performed by surgical residents. The purpose of the study is to evaluate those observations. In a retrospective nonrandomized study, conducted between February 1992 and December 1997, 285 laparoscopic operations for acute cholecystitis were analyzed. Those performed by attending surgeons were compared with those performed by residents assisted by attending surgeons. Of 123 laparoscopic operations performed by laparoscopic surgeons between February 1992 and September 1995, 20.3% were converted to laparotomy, compared with 41.3% of the 29 operations performed by the residents (p < 0.017), with no increase in complication rate. Factors like male sex, duration of upper abdominal pain, and severity of the inflammatory process were not significantly different in both groups. The residents' seniority did not influence the conversion rate. A constant and significant decrease in conversion rate to laparotomy was observed over the course of time, as the study proceeded to December 31, 1997 (p < 0.01). We conclude that the performance of difficult laparoscopic cholecystectomy by residents with the assistance of attending surgeons is feasible, but carries a higher conversion rate to laparotomy for reasons that are not entirely clear. The possibility of a learning curve of the residents is suggested.

Acute Disease↗

PubMed1998

Innervation territories of single sympathetic C fibers in human skin.

Microneurography techniques were used to record action potentials from unmyelinated nerve fibers (C fibers) in the cutaneous fascicles of the peroneal nerve in healthy volunteers. C units were identified by their long latency responses to electrical stimulation of their terminals in the skin. Their responsiveness to mechanical or heat stimuli applied to the skin or to sympathetic reflex provocation tests was determined by transient slowing of conduction velocity following activation (marking technique). In a sample of 381 C units, 59 were unresponsive to mechanical and thermal stimulation of their endings, but responded to sympathetic reflex provocation tests, e.g., arousal or deep inspiration. They were classified as sympathetic efferent units. On average, conduction velocities of sympathetic units were lower (0.78 +/- 0.12 m/s, mean +/- SD) than those of mechano-heat (CMH) or mechanoresponsive (CM) afferent C units (0.91 +/- 0.14 m/s). Endings of most of the sympathetic units were located in the skin of toes or in the foot dorsum. Innervation territories of 16 sympathetic units were mapped by means of conditioning transcutaneous electrical stimuli. Twelve units had one continuous skin territory, whereas two units had two and two other units had three and five separate territories, respectively. The mean innervated area was 128 mm2 (range: 24-350 mm2). Innervation territories of sympathetic units were of approximately the same size in different skin regions on the lower leg, foot, or toes. Based on responses to whole body cooling and warming, two units were tentatively classified as vasoconstrictor and sudomotor units, respectively. Eleven units were tested for responsiveness to iontophoresis of acetylcholine in their innervation territories. In five of them, activity was induced that was not due to central reflex activity but instead due to antidromic activation from the peripheral terminals. Iontophoresis of saline or histamine was ineffective. These findings confirm the existence of excitatory cholinergic receptors in the terminal membrane of some sympathetic units, possibly sudomotors.

Acetylcholine↗

PubMed1997

Specific C-receptors for itch in human skin.

In microneurography experiments 56 unmyelinated nerve fibers were studied in the cutaneous branch of the peroneal nerve of healthy volunteers. Units were identified with the "marking" technique as mechanically and heat-responsive (CMH; n = 30), heat-responsive (CH; n = 13), or unresponsive to mechanical and heat stimulation (CMiHi; n = 13). None of the units showed spontaneous activity. These units were tested for responsiveness to iontophoresis of histamine (1 mA, 20 sec) from a small probe (diameter, 6 mm), which induced itch sensations lasting several minutes. Twenty-three units were unresponsive to histamine, and 25 units responded weakly with a few spike discharges after iontophoresis. Eight units, however, responded with sustained discharges to histamine, and their discharge patterns were matching the time course of the itch sensations. All C-units in this group were mechanically insensitive, and five of them were heat-responsive. They had very low conduction velocities of only 0.5 m/sec, on average, which is significantly lower than conduction velocities of the "polymodal" CMH units. This slow conduction velocities attributable to small axon diameters may be one reason why these units have not been encountered in previous studies. Histamine-sensitive C-units had very large innervation territories extending up to a diameter of 85 mm on the lower leg. We conclude that these C-fibers represent a new class of afferent nerve fibers with particularly thin axons but excessive terminal branching. This type of C-fiber probably represents the afferent units long searched for mediating itch sensations.

Adult↗

PubMed1997

Plasma extravasation and neuropeptide release in human skin as measured by intradermal microdialysis.

Time course of plasma extravasation in neurogenic inflammation elicited by histamine iontophoresis and topical capsaicin application was measured in vivo by a modified intradermal microdialysis technique in humans. Single linear plasmapheresis fibers were inserted intracutaneously at the volar forearm and perfused with Ringer's solution (4 microl/min) with one microdialysis fiber located at the planned stimulation site and a second inside the axon reflex area. Protein concentration in the dialysate increased by 300% in the histamine wheal but no increase was found in the surrounding flare area. There was no protein extravasation in the skin treated with capsaicin nor in the surrounding flare region. Inside the histamine-induced flare reaction a significant increase of calcitonin gene related peptide (CGRP) was found, whereas the increase of substance P (SP) was not significant.

Adult↗

PubMed1997

Myoblastomatoid carcinoma of the breast: an unusual variant of apocrine carcinoma: report of a case with fine-needle aspiration cytology and immunohistochemical study.

Fine-needle aspiration cytology, immunohistochemistry, and histopathologic findings are described in a case of myoblastomatoid carcinoma of the breast. The aspirate contained many small and large clusters of cohesive atypical cells with abundant foamy-to-granular cytoplasm and nuclei that show moderate pleomorphism. These tumors can be easily misinterpreted as either fibrohistiocytic or myoblastomatoid (granular cell) tumors, and by using immunohistochemical stains, the epithelial origin can be elucidated. This case report provides the first description of the fine-needle aspiration cytomorphology of this distinctive variant of apocrine carcinoma.

Aged↗

PubMed1997

Neurotoxicity of long-term low-level exposure to carbon disulphide: results of questionnaire, clinical neurological examination and neuropsychological testing.

OBJECTIVE: Carbon disulphide (CS2) is highly neurotoxic. There is ample evidence of damage to the peripheral and central nervous system. The air concentration at which such adverse effects can first be observed is presently a subject of controversy. METHODS: In a cross-sectional study of CS2-exposed workers from the viscose industry and healthy controls, data on neurological complaints, basic laboratory diagnosis, clinical neurological examination and neuropsychological testing were evaluated. Data were from 222 workers in the viscose industry exposed to CS2 and 191 employees from the same factory with similar physical and psychological stress factors but without occupational contact with neurotoxic substances. Multiple linear or multiple logistic regression analysis was used to check for statistical differences. RESULTS: The median of the CS2-measurements using personal air sampling was below the current maximum concentration permissible (MAK value) in Germany (10 ppm) in all departments. The threshold limit value was, however, exceeded in almost 10% of the persons investigated. Exposure fluctuated between < 0.2 and 65.7 ppm (median of all departments was 4.02 ppm). As a parameter of internal exposure, CS2-metabolite 2-thio-1,3-thiazolidine-4-carboxylic acid (TTCA) concentrations in the urine of the exposed persons were between < 0.16 and 10.9 mg/g creatinine (median 1.43 mg/g). CONCLUSIONS: Neither an increase in subjective complaints nor an increase in pathological findings in clinical-neurological and neuropsychological examination could be found in persons exposed to CS2 at the exposure levels described.

Adult↗

PubMed1997

Electrophysiological investigation of central, peripheral and autonomic nerve function in workers with long-term low-level exposure to carbon disulphide in the viscose industry.

OBJECTIVE: Neurotoxicity of carbon disulphide (CS2) is well known. The air concentration at the workplace at which such adverse effects can first be observed is the subject of controversial discussion. METHODS: In a cross-sectional study on CS2-exposed workers peripheral motor and sensory nerve conduction studies, somatosensory evoked potentials, thermotesting and investigation of forced respiration sinus arrythmia have been carried out. The data from 222 workers exposed to CS2 in the viscose industry were evaluated and compared with data from 191 employees from the same factory with similar physical and psychological stress factors but without detectable occupational contact to neurotoxic substances. Median exposure to CS2 was below the currently valid occupational-medical threshold limit value (MAK-value) of 10 ppm. Multiple linear or multiple logistic regression analysis was used to check for statistical differences. RESULTS: Binary evaluation (comparison of exposed persons versus controls after multiple linear regression) revealed a slightly lower value in the exposed group for the motor nerve conduction velocity (MNCV, -0.76 m/s, median 48 m/s), but a long way from pathological thresholds. No dose-response relationship could be found within the exposed group for any evaluation criteria of CS2-exposure. Somatosensory evoked potentials, thermotesting and analysis of heart rate variability yielded no indication of a neurotoxic effect of CS2. CONCLUSION: Isolated decrease of MNCV in binary evaluation is, with regard to the known mechanism of CS2-neurotoxicity and the lack of a dose-response relationship, obviously not due to toxic effects. We interpret our results as showing that an adverse effect of carbon disulphide at the exposure ranges found was not detectable in the exposed group.

Adult↗

PubMed1997

Laparoscopic management of lumbar hernia.

We describe (for the first time) a laparoscopic approach to repair an acquired superior triangle lumbar hernia in a morbidly obese woman by using prosthetic mesh. Such a technique provides an excellent anatomic view, thus avoiding injury to structures in proximity to the hernia during repair; eventually the well-known advantages of such approach result.

Female↗

PubMed1997

Clinical and morphological phenotype of HMSN 1A mosaicism.

Clinical, neurophysiological and morphological studies on a patient with mosaicism of the 17p11.2 duplication were performed in detail for the first time. Since duplication occurs during paternal meiosis, a somatic reversion is suggested, leading to mosaicism. The proportion of nuclei with duplication varied markedly between 49% in blood cells and 74% in tissue from the sural nerve. Clinically, mild symptoms of a motor and sensory neuropathy were present. However, neurophysiological changes and findings in the sural nerve biopsy were consistent with a typical hereditary motor and sensory neuropathy type 1 (HMSN 1). Differing clinical findings in patients with mosaicism of the 17p11.2 duplication may be explained by a varying degree and/or time of reversion.

Adult↗

PubMed1996

Effect of highly fragmented DNA on PCR.

We characterized the behavior of polymerase chain reactions (PCR) using degraded DNA as a template. We first demonstrated that fragments larger than the initial template fragments can be amplified if overlapping fragments are allowed to anneal and extend prior to routine PCR. Amplification products increase when degraded genomic DNA is pretreated by polymerization in the absence of specific primers. Secondly, we measured nucleotide uptake as a function of template DNA degradation. dNTP incorporation initially increases with increasing DNA fragmentation and then declines when the DNA becomes highly degraded. We demonstrated that dNTP uptake continues for >10 polymerization cycles and is affected by the quality and quantity of template DNA and by the amount of substrate dNTP. These results suggest that although reconstruction of degraded DNA may allow amplification of large fragments, reconstructive polymerization and amplification polymerization may compete. This was confirmed in PCR where the addition of degraded DNA reduced the resultant product. Because terminal deoxynucleotidyl transferase activity of Taq polymerase may inhibit 3' annealing and restrict the length of template reconstruction, we suggest modified PCR techniques which separate reconstructive and amplification polymerization reactions.

DNA↗

PubMed1996

Laparoscopic management of acute cholecystitis. Prognostic factors for success.

BACKGROUND: Laparoscopic cholecystectomy for acute cholecystitis is considered feasible and safe, but it is associated with a higher rate of conversion to laparotomy than elective cholecystectomy because of technical reasons and anatomical changes related to the inflammatory process. The value of several factors that might influence its successful completion has not been studied completely yet, including the role of residents in operating such cases under attending-surgeon surveillance. METHODS: In a retrospective nonrandomized study, the medical charts of 182 patients that were operated for acute cholecystitis (94 of whom via the laparoscopic approach) were studied. The study was also conducted to study the effect of residents as operators. RESULTS: Male sex, duration of right upper abdominal pain, and the severity of the inflammatory process have all been significantly and independently correlated with increased conversion rate to laparotomy. Operation time was not longer than that of the open approach, and hospital stay and complication rate were lower. Operations performed by residents were associated with twofold conversion rate to laparotomy, without increased complication rate (p < 0.012). CONCLUSIONS: Laparoscopic management of acute cholecystitis is feasible and safe. Considering the factors discussed above, lowering the threshold for conversion is necessary in selected cases to maintain low morbidity rate. Integrating laparoscopic cholecystectomy for acute cholecystitis into surgical residency should be studied.

Acute Disease↗

PubMed1996

A technique for second-look laparoscopy in the obese patient.

A technique for second-look laparoscopy in an obese patient suffering from acute mesenteric ischemia is described. A device composed of a 10-mm trocar-sleeve and a large Foley catheter was used, which enables its proper fixation through the abdominal wall, without causing any intestinal damage.

Abdominal Muscles↗