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Biomedical subjects

H D Becker

Publications and source records attributed to H D Becker.

At least 109 records · Page 6Linked to original sources

[Enteral feeding of problem patients: replacement of surgical catheter jejunostomy by an endoscopic concept].

Percutaneous endoscopic gastrostomy (PEG), is widely used as a safe, effective method of providing enteral nutrition to patients in whom oral feeding is not possible. However, in patients with malnutrition after partial or total gastrectomy, anastomotic insufficiency after gastric resection or esophageal resection with gastric pull-up, esophageal perforation and fistulas, the stomach cannot be punctured. In these cases endoscopic percutaneous jejunostomy (EPJ) by direct punction of the small intestine is a reasonable alternative; the technique is described, and the results of a series of 103 EPJs are reported.

Adolescent↗

[Differential achalasia therapy].

The early relief of esophageal outflow obstruction in patient with achalasia diminishes complaints and avoids deterioration as a result of this disease. The pneumatic myotomy of the lower esophageal sphincter is the initial therapeutic concept. After two unsuccessful dilations, the laparoscopic myotomy with semifundoplication shows the best long-term results in the treatment of achalasia with fewer complications.

Adult↗

Existence of two distinct aspartyl-tRNA synthetases in Thermus thermophilus. Structural and biochemical properties of the two enzymes.

Two aspartyl-tRNA synthetases (AspRSs) were isolated from Thermus thermophilus HB8. Both are alpha2 dimers but differ in the length of their polypeptide chains (AspRS1, 68 kDa; and AspRS2, 51 kDa). Both chains start with Met and are deprived of common sequences to a significant extent. This rules out the possibility that AspRS2 is derived from AspRS1 by proteolysis, in agreement with specific recognition of each AspRS by the homologous antibodies. DNA probes derived from N-terminal amino acid sequences hybridize specifically to different genomic DNA fragments, revealing that the two AspRSs are encoded by distinct genes. Both enzymes are present in various strains from T. thermophilus and along the growth cycle of the bacteria, suggesting that they are constitutive. Kinetic investigations show that the two enzymes are specific for aspartic acid activation and tRNAAsp charging. tRNA aspartylation by the thermostable AspRSs is governed by thermodynamic parameters which values are similar to those measured for mesophilic aspartylation systems. Both thermophilic AspRSs are deprived of species specificity for tRNA aspartylation and exhibit N-terminal sequence signatures found in other AspRSs, suggesting that they are evolutionarily related to AspRSs from mesophilic prokaryotes and eukaryotes. Comparison of the efficiency of tRNA aspartylation by each enzyme under conditions approaching the physiological ones suggests that in vivo tRNAAsp charging is essentially ensured by AspRS1, although AspRS2 is the major species. The physiological significance of the two different AspRSs in T. thermophilus is discussed.

Amino Acid Sequence↗

Perianal abscess in Crohn's disease.

PURPOSE: Perianal disease is frequent in patients with Crohn's disease, and many of these patients will eventually have abscess formation. In a prospective follow-up study, we evaluated factors influencing the occurrence and recurrence of perianal abscesses. METHODS: Of 126 consecutive patients with perianal Crohn's disease seen regularly in an outpatient clinic, 61 (48.4 percent) had at least one perianal abscess (mean follow-up, 32 +/- 17 months). In all, 110 episodes of an abscess with 145 anatomically distinct abscesses were documented. RESULTS: The occurrence of first abscesses was dependent on the type of anal fistula (ischiorectal, 73 percent; transsphincteric, 50 percent; superficial, 25 percent; P < 0.02). Surgical therapy consisted of seton drainage (34 percent), mushroom catheter drainage (49 percent), or incision and drainage (29 percent) and led to inactivation in all patients. Cumulative two-year recurrence rates after the first and second abscess were 54 and 62 percent, respectively. Abscess recurrence was less frequent in patients with a stoma (13 vs. 60 percent in patients without stoma after two years) and in patients with superficial anal fistulas (0 vs. 55 percent/56 percent in patients with transsphincteric/ischiorectal fistulas). Only two abscesses recurred within one year after removal of seton drainage, whereas 13 abscesses recurred with the seton still in place. Neither intestinal nor rectal activity of Crohn's disease significantly influenced the occurrence of an abscess. During the study period, only two patients developed partial stool incontinence. CONCLUSION: Development of perianal abscesses in Crohn's disease depends on the fecal stream and the anatomic type of anal fistula. Seton and catheter drainage are safe and highly effective in treatment. Long-term use of setons to prevent recurrent abscesses is not supported by our data.

Abscess↗

[Calcium and bone metabolism after gastrectomy].

Disturbances in calcium and bone metabolism after gastrectomy have long been recognized. It has been suggested that due to impaired calcium absorption after gastrectomy, serum calcium is decreased, being counter-regulated by parathyroid hormone release and 1,25-(OH)2-vitamin D formation. Both parathyroid hormone and 1,25-(OH)2-vitamin D are known to release calcium from bone, resulting in bone mass loss and increased fracture risk in some of the gastrectomized patients. No therapy is currently generally agreed on, although supplementation of vitamin D and calcium has been suggested repeatedly. A review on the current understanding of calcium and bone metabolism after gastrectomy is given.

Aged↗

High prevalence of bone disorders after gastrectomy.

BACKGROUND: Studies indicate that gastrectomy might alter calcium and bone metabolism, resulting in bone disorders. No data are currently available on the prevalence of bone disorders after gastrectomy. METHODS: Sixty gastrectomy patients were investigated for serum parameters of calcium and bone metabolism 5 to 20 years postoperatively and compared to an age- and sex-matched healthy control population. Forty patients agreed to a radiological investigation of the spine by anterior-posterior and lateral radiographs of the thoracic and lumbar spine and by computed tomography (CT) osteodensitometry. RESULTS: Serum calcium and 25-(OH)-vitamin D were decreased in gastrectomized patients, while parathyroid hormone and 1,25-(OH)2-vitamin D were increased. Serum parameters of calcium metabolism were altered in as many as 68% of patients. We found 31 vertebral fractures in 13 patients, 30 grade 2 vertebral deformities in 18 patients, and osteopenia in 15 patients, corresponding to a prevalence of 33%, 45%, and 37% in gastrectomized patients, respectively. The overall rate of gastrectomy patients having vertebral fractures and/or osteopenia was 55%. The risk of having a vertebral deformity was increased by more than sixfold after gastrectomy. Our study is the first report evaluating vertebral deformities in gastrectomized patients, and the largest series of gastrectomized patients investigated by CT osteodensitometry. CONCLUSION: We found a high prevalence of bone disorders in gastrectomized patients, possibly resulting from disorders in calcium metabolism. Postgastrectomy bone disease might derive from a calcium deficit, which increases calcium release from bone and impairs calcification of newly build bone matrix.

Absorptiometry, Photon↗

[High frequency jet ventilation during tracheal resection in children and infants].

Between 1986 and 1996, 16 infants and children less than 11 years of age (m = 11, f = 5) underwent resections for acquired or congenital tracheobronchial stenoses. During this period, various techniques of total intravenous anaesthesia (TIVA) were employed (midazolam, fentanyl, pancuronium; propofol, fentanyl, pancuronium). During the phase of dividing the airways, high-frequency-jet ventilation (HFJV) into the trachea or the main bronchi by 8-12Fr catheter(s) was applied for 10-75 min with driving pressures between 0.3-1.8 bar, frequencies between 100-200/min, I:E ratio between 1:4-1:1, and FjetO2 1.0. Catheter position was controlled visually, gas exchange was monitored by pulse oximetry and blood gas analysis. There were two incidents of transient hypoxaemia (paO2 less than 60 mmHg), and 4 cases of hypercapnia (paCO2 more than 45 mmHg). No complications due to the HFJV-catheter technique, such as barotrauma or aspiration were seen. All children were kept postoperatively on a ventilator due to swelling of the airway anastomosis. In 5 children ventilator treatment exceeded 7 days, 3 children were discharged tracheostomised. These observations serve to confirm that HFJV is capable of maintaining gas exchange during tracheal resection in infants and children, if the following prerequisites are met: 1. Tracheobronchial pathology suitable for poststenotic placement of jet catheter. 2. No respiratory impairment by parenchymal pathology. 3. Monitoring by continuous visual control of respiratory mechanics, pulse oximetry and blood gas analysis. Cardiopulmonary bypass should be applied if airway pathology precludes safe placement of jet catheters, or in the presence of parenchymal respiratory failure.

Anesthesia, General↗

Calcium regulation and bone mass loss after total gastrectomy in pigs.

OBJECTIVE: Total gastrectomy often results in postgastrectomy bone disease with decreased bone mass and increased fracture risk. To further elucidate the mechanisms of postgastrectomy bone disease, the authors investigated calcium metabolism and bone mineral density after total gastrectomy in pigs. SUMMARY BACKGROUND DATA: Postgastrectomy bone disease can present as osteomalacia, osteoporosis in excess of normal aging, or a combination of both. The underlying mechanisms are insufficiently understood and need further investigation. METHODS: Growing minipigs were gastrectomized and compared with fed-matched, sham-operated control p gs for 1 year. Calcium absorption, serum calcium, parathyroid hormone, 25-(OH)-vitamin D, 1,25-(OH)2-vitamin D, alkaline phosphatase, and computed tomography bone mineral density were measured in three monthly intervals. RESULTS: Total gastrectomy resulted in impaired calcium absorption, reduced serum calcium and 25-(OH)-vitamin D, increased parathyroid hormone and 1,25-(OH)2-vitamin, and reduced bone mineral density compared with fed-matched, sham-operated control pigs. CONCLUSIONS: The authors data indicate that a reduced serum calcium activates counter-regulatory mechanisms, resulting in calcium mobilization from the bone. Possibly, calcium and vitamin D supplementation after total gastrectomy might prevent postgastrectomy bone mass loss.

Animals↗

Recombinant human transforming growth factor beta 3 accelerates gastric ulcer healing in rats.

BACKGROUND: Gastric ulcer healing is mediated by various endogenous growth factors. In this experimental study effect of locally and systemically applied recombinant human transforming growth factor beta 3 (rhTGF-beta 3) on gastric ulcer healing was investigated in the rat. METHODS AND RESULTS: Gastric ulcers were induced with a cryoprobe, and ulcer healing was evaluated 7 days after local infiltration (0.5 micrograms, 1.0 microgram, 2.5 micrograms, and 50 micrograms) or systemic (intravenous) application of TGF-beta 3 (500 micrograms/kg body weight). Compared with controls, a dose-dependent stimulation of ulcer healing (as evidenced by a reduction in ulcer size) was observed 7 days after local infiltration of TGF-beta 3 (1.0 microgram, 2.5 micrograms, and 50 micrograms). Corresponding increases in the levels of proliferating cell nuclear antigen (PCNA) and intracellular TGF-beta 3 expression and a downregulation of the TGF-beta type-II receptor expression were also observed in the granulation tissue of the ulcer margins. Systemic application of TGF-beta 3 produced effects similar to those observed after local treatment with 50 micrograms of the compound. CONCLUSION: Local and systemic TGF-beta 3 treatment accelerates gastric ulcer healing in rats.

Animals↗

Indications and results of local treatment of rectal cancer.

BACKGROUND: Local therapy of early rectal carcinoma has become an alternative to the classical radical operation which has a higher morbidity and mortality rate. METHODS: Rectal carcinoma was treated by transanal endoscopic microsurgery (TEM) in 113 patients. The indications for the procedure were pT1 low-risk tumour, advanced tumour in high-risk patients, and patients who refused more radical surgery based on oncological guidelines. RESULTS: Sixty-four patients had pT1, 33 pT2 and 16 pT3 tumours. No patient died as a result of TEM. The rate of complications which needed operative intervention was 7 per cent. So far, two of the patients treated by local resection of pT1 low-risk tumours have had a recurrence. In both cases, a secondary procedure was possible with curative intent. CONCLUSION: Patients with pT1 rectal tumours represent a suitable group for local treatment because of the acceptability of the procedure and the low recurrence rate.

Adult↗

Progression and prognosis of Crohn's colitis.

BACKGROUND: Inflammation refractory to medical treatment frequently characterizes the course of Crohn's colitis, often leading to colectomy and need for a stoma. The influence of disease extent within the colon on prognosis and disease progress over time has not been studied so far. AIMS: We evaluated the disease progress and the long-term outcome in 323 patients with Crohn's colitis followed-up for a mean of 9.8 years. METHODS: The charts were analyzed retrospectively, the mean number of documented examinations was 18.5 per patient. The influence of disease pattern, rectal disease and perianal fistulas on the long-term outcome was evaluated using actuarial methods and independent factor analysis. RESULTS: The probabilities of having pancolitis or rectal disease were 77.1% and 78.8% after 15 years, respectively, and higher in patients with initially left-sided or segmental colitis compared with right-sided colitis. The chance of having perianal fistulas was 43.3% after 15 years. The risk of undergoing resectional colonic surgery was 62.2% after 15 years and higher in the presence of right-sided colitis. The cumulative risk of colectomy was 18.2% after 15 years and higher in patients with pancolitis, left-sided colitis or in the presence of perianal fistulas. The 15-year probabilities of proctectomy (12%) and of having a temporary stoma (21%) were only influenced by the presence of perianal fistulas but not by rectal disease or pattern of colitis. CONCLUSIONS: Most patients with colonic Crohn's disease will eventually have pancolitis but only 20% of them will loose the colon. The proctectomy rate is low despite a high frequency of rectal disease. Perianal fistulas and the presence of total or left-sided colonic involvement are adverse risk factors with regard to preservation of colonic length.

Adult↗

[Sex differences in neuromodulation of mucosal mast cells in the rat jejunum].

The effect of electrical stimulation of both cervical vagal nerves on mucosal mast cells in the jejunum was investigated in an in vivo animal model with rats of both sexes. Males showed a significant increase of mast cell densities after electrical stimulation (1.0 mA, 5 Hz, 5 ms, 12 min) in the lamina propria. Simultaneously, we observed a significant increase of tissue histamine levels (ANOVA: P < 0.05), whereas serum levels remained unchanged. However, even though females had significantly higher levels throughout compared to males (ANOVA: P < 0.05), they did not show any significant reaction to electrical stimulation. These in vivo data support morphological and in vitro data from other investigators, who hypothesized a functional interaction between mucosal mast cells and nerves. However, degranulation seems to be a poor in situ indicator for mast-cell stimulation, as mast-cell densities increased in males, while the percentage of degranulated cells remained the same in all groups (about 40%). Instead, electrical stimulation of the vagal nerve seems to trigger histamine synthesis, or simply stabilization of mast cells. Interestingly, this phenomenon seems to be sex-dependent, suggesting a regulatory role for sex hormones in this scenario.

Animals↗

[Prognostic factors in treatment of diabetic foot ulcers].

138 patients with nonhealing diabetic foot ulcers were treated between 1994 and 1996. Sixty-nine percent of these foot ulcers healed within 17 weeks. Heel ulcers had a significantly lower healing rate, probably because of the difficulty of taking weight-bearing off this zone. Ischemia also correlated well with low healing rates, underlining the importance of vascular diagnosis and surgery. Since compliance is the most significant factor for success, it is mandatory to educate the patient about his disease and prevent further complications.

Adult↗