Biomedical subjects

U Hohmann

Publications and source records attributed to U Hohmann.

At least 19 recordsLinked to original sources

PubMed2006

Epiphrenic esophageal diverticulum after laparoscopic placement of an adjustable gastric band.

A morbidly obese woman (BMI 56 kg/m2) in 1998 underwent laparoscopic placement of an adjustable gastric band by the perigastric approach. 5 years later, she complained of reflux and weight regain. X-ray with contrast revealed pouch dilatation. She subsequently underwent a laparoscopic revision including retrocardia band replacement using the pars flaccida technique. During the further course, an epiphrenic diverticulum was diagnosed. Because of danger of perforation of the large thin-walled diverticulum and the esophageal motility disorder, the band was laparoscopically removed and the diverticulum was resected via a transhiatal approach. This case presents a very rare complication after placement of a gastric band and its successful management.

Device Removal↗

PubMed2005

Bacterial artificial chromosome-derived molecular markers for early bolting in sugar beet.

Early bolting in sugar beet (Beta vulgaris L.) is controlled by the dominant gene B. From an incomplete physical map around the B gene, 18 bacterial artificial chromosomes (BACs) were selected for marker development. Three BACs were shotgun-sequenced, and 61 open reading frames (ORFs) were identified. Together with 104 BAC ends from 54 BACs, a total number of 55,464 nucleotides were sequenced. Of these, 37 BAC ends and 12 ORFs were selected for marker development. Thirty-one percent of the sequences were found to be single copy and 24%, low copy. From these sequences, 15 markers from ten different BACs were developed. Ten polymorphisms were determined by simple agarose gel electrophoresis of either restricted or non-restricted PCR products. Another five markers were determined by tetra-primer amplification refractory mutation system-PCR. In order to select candidate BACs for cloning the gene, genetic linkage between seven markers and the bolting gene was calculated using 1,617 plants from an F2 population segregating for early bolting. The recombination values ranged between 0.0033 and 0.0201. In addition, a set of 41 wild and cultivated Beta accessions differing in their early bolting character was genotyped with seven markers. A common haplotype encompassing two marker loci and the b allele was found in all sugar beet varieties, indicating complete linkage disequilibrium between these loci. This suggests that the bolting gene is located in close vicinity to these markers, and the corresponding BACs can be used for cloning the gene.

Base Sequence↗

PubMed2005

[Band migration. A late complication of gastric banding].

BACKGROUND: Adjustable silicone gastric banding is an effective and safe treatment for morbid obesity. Migration of the band through the stomach wall is a long-term complication. The causes, clinical symptoms, timing, and incidence of band migration have not yet been investigated. METHODS: We report our experience over 9 years. Between February 1995 and February 2004, we performed adjustable silicone gastric banding in 161 patients, with follow-up of about 90.5% of cases. Mean follow-up time was 60.4 months. Cases of erosion were studied retrospectively. RESULTS: Eight patients (4.9%) developed band migration. In seven, the migration occurred between 30 and 86 months after band implantation. In one case, the migration occurred 10 months after laparoscopic repositioning of the band to avoid pouch dilatation. In all cases, the bands were removed. CONCLUSION: Band migration is a late complication after gastric banding that requires band removal. Various symptoms and complications of band migration influence the kind of band removal. The causes of band migration and its treatment are discussed.

Female↗

PubMed2005

[Long-term results after gastric banding].

BACKGROUND: Adjustable gastric banding is a popular bariatric operation in Europe. The rate of long-term complications like pouch dilatation, slippage and band migration and the long-term effect of weight loss are reported in meta-analysis and few studies for a period of more than five years. We report on experiences after gastric banding. METHODS: Over a period of 10 years 168 patients with morbid obesity were treated with gastric banding. Preoperative data, postoperative weight loss and long-term complications were prospectively obtained and retrospectively analyzed. RESULTS: Mean age of the patients was 41.7 years with a mean preoperative BMI of 49.6 kg/m2. No intraoperative or postoperative death occurred in the first 30 postoperative days. Intraoperative conversion rate was 7.1 %. 79.8 % of the patients (n = 134) were available for follow up (mean follow-up time 66.7 months). Long-term complications occurred in 22.5 % of the patients. 30 complications (17.8 %) were related to the band and 8 (4.7 %) to the access-port or to the tube. Mean excess weight loss was 39.6, 47.3, 44.2, 43.4 and 32 % after 1, 2, 4, 5 and 8 years. CONCLUSIONS: Laparoscopic gastric banding can achieve an effective weight loss. However band-related and functional complications will influence the late outcome. Pathways to choose the best surgical method for the individual patient are necessary to reduce failures after gastric banding.

Adult↗

PubMed2005

Rhabdomyolysis after biliopancreatic diversion with duodenal switch.

Rhabdomyolysis is an uncommon event in bariatric surgery. It can be caused by ischemia, crush injury, alcohol ingestion and drug intake, and as a consequence renal failure can develop. A few reports indicate that patients undergoing bariatric surgical intervention are at risk for rhabdomyolysis. A super-obese male (BMI 52 kg/m2) is reported, who underwent laparoscopic biliopancreatic diversion with duodenal switch (BPD/DS). Operative time was 265 minutes, and the BPD/DS operation was uneventful. Post-operatively, the patient complained of pain in both hips and the left shoulder, and suffered oliguria. He was treated with fluids (isotonic saline), bicarbonate, and mannitol. Despite this, he developed renal failure, which subsequently required hemodialysis. The patient died from arrhythmia and cardiac arrest on the 8th postoperative day. Obese patients undergoing bariatric surgery are at risk of rhabdomyolysis. Prolonged compression of the muscles during the surgical intervention, in long laparoscopic procedures, predisposes to this complication.

Adult↗

PubMed2004

Ultrastructural analysis of chromatin in meiosis I + II of rye (Secale cereale L.).

Scanning electron microscopy (SEM) proves to be an appropriate technique for imaging chromatin organization in meiosis I and II of rye (Secale cereale) down to a resolution of a few nanometers. It could be shown for the first time that organization of basic structural elements (coiled and parallel fibers, chromomeres) changes dramatically during the progression to metaphase I and II. Controlled loosening with proteinase K (after fixation with glutaraldehyde) provides an enhanced insight into chromosome architecture even of highly condensed stages of meiosis. By selective staining with platinum blue, DNA content and distribution can be visualized within compact chromosomes as well as in a complex arrangement of fibers. Chromatin interconnecting threads, which are typically observed in prophase I between homologous and non-homologous chromosomes, stain clearly for DNA. In zygotene transversion of chromatid strands to their homologous counterparts becomes evident. In pachytene segments of synapsed and non-synapsed homologs alternate. At synapsed regions pairing is so intimate that homologous chromosomes form one filament of structural entity. Chiasmata are characterized by chromatid strands which traverse from one homolog to its counterpart. Bivalents are characteristically fused at their telomeric regions. In metaphase I and II there is no structural evidence for primary and secondary constrictions.

Centromere↗

PubMed2003

A bacterial artificial chromosome (BAC) library of sugar beet and a physical map of the region encompassing the bolting gene B.

In sugar beet (Beta vulgaris L.), early bolting is caused by a single dominant gene, designated B. Twenty AFLP markers selected from a 7.8-cM segment of the B region on chromosome 2 were used to screen a YAC library, and a first-generation physical map including the B gene, made up of 11 YACs, was established. Because the genome coverage of the YAC library was low, a BAC library was constructed in the vector pBeloBAC11. This library consists of 57,600 clones with an average insert size of 116 kb, corresponding to 8.8 genome equivalents. Screening of the BAC library with chloroplast and mitochondrial DNA probes indicated that less than 0.1% of the clones contained organelle-derived DNA. To fill the gaps in the physical map around the B gene, the BAC library was screened with four AFLP markers and 10 YAC-derived probes. In total, 54 different BACs were identified. Overlaps between BACs were detected by using BAC termini amplified by PCR as probes, and by RFLP fingerprinting. In this way, a minimal tiling path of the central 4.6-cM region was constructed, which consists of 14 BACs. The B locus was localized to a 360-kb contig, a size which makes positional cloning of the gene feasible.

Beta vulgaris↗

PubMed2003

[Lesions of the spleen in chronic pancreatitis by thrombophlebetic splenomegaly and cyst penetration].

UNLABELLED: Chronic pancreatitis leads to changes of nearby organs with possible acute and chronic complications including lesions of the spleen. Among 341 patients operated upon between January 1981 and June 2002 in the surgical department Gera, we found 7 spontaneous spleen ruptures or such after minimal trauma and 4 pseudocysts, which expanded to the splenic hilus. In all cases splenectomy was carried out with resection of the tail of the pancreas with or without drainage of the pancreas. 2 patients with a history of splenectomy after minimal trauma underwent duodenum-preserving resection of the pancreatic head to Frey, and distal pancreatectomy, resp. CONCLUSIONS: Lesions of the spleen belong to the rare complications of chronic pancreatitis. With known case history and mostly delayed course, the operative concept must be concentrated not only on the splenic lesion but also on the therapy of the chronic pancreatitis.

Adult↗

PubMed2003

[Rare tumors of the pancreas].

From 1984 to 2001, 486 operations were carried out at the surgical clinic in Gera for pancreatic neoplasms, including 49 patients with rare neoplasms of the pancreas. In 23 patients malignant pancreatic tumors were present (9 solitary metastases, 9 endocrine carcinomas, 2 cystadenocarcinomas, 2 schwannomas and one non-Hodgkin's lymphoma). In 28 benign lesions a resection of the tumor was performed, concerning 8 insulinomas, 8 serous cystadenomas, 3 mucinous cystadenomas and 4 rare cystic tumors. A sarcoidosis, an autoimmune pancreatitis and a radiation fibrosis were diagnosed in 3 patients operated under the suspicion of a malignant pancreatic tumor. By means of own case examples and data from the literature these rare entities are described with their diagnostic and therapeutic special features.

Adenocarcinoma↗

PubMed2002

C-to-U conversion in the intercistronic ndhI/ ndhG RNA of plastids from monocot plants: conventional editing in an unconventional small reading frame?

Editing of plastid RNAs proceeds by C-to-U, in hornwort species also by extensive U-to-C, transitions, which predominantly lead to the restoration of codons for structurally and/or functionally important, conserved amino acid residues. So far, only one instance of editing outside coding regions has been reported - in the psbL/ psbF intergenic region of Ginkgo biloba. This site was proposed to have no functional importance. Here we present an evaluation of an editing site in the ndhI/ ndhG intergenic region in a related group of monocot plants. Efficient editing of this site, as well as the phylogenetic conservation of the resulting uridine residue, point at an important role for the sequence restored by editing. Two potential functions can be envisaged. (1) RNA secondary structure predictions suggest that the C-to-U conversion at this site can lead to a modified stem/loop structure of the ndhG 5' UTR, which could influence ndhG expression. (2) Alternatively, editing of the ndhI/ ndhG intergenic region may tag a so far unidentified small (12-codon) ORF, and lead to the restoration of a conserved phenylalanine codon. A screen with specific antibodies elicited against the putative peptide failed to detect such a peptide in chloroplast fractions. However, this failure may be attributable to its low and/or development-specific expression.

Amino Acid Sequence↗

PubMed2001

[Intraoperative diagnosis of pheochromocytoma preoperative symptoms in a case of Recklinghausen's disease].

Phaechromocytoma is a rare catecholamine secreting tumor, which occasionally presents as a life threatening crisis in association with surgery and anesthesia. We report a 58-year-old women with known Recklinghausen's disease who was admitted for elective resection of a pancreas tail cystadenoma. A cystadenocarcinoma was taken into account differential diagnostically. No clinical symtoms or signs pointing to a hormone active tumor were found preoperatively. After opening of the abdomen and palpation of the tumor, a hypertensive crisis occurred accompanied by considerable tachycardia, leading to the tentative diagnosis of a phaeochromocytoma in connection to the known phacomatosis. The hypertensive crisis was treated with nitroglycerin and esmolol. The putative tumor of the pancreas represented itself as an adrenal tumor without relationship to the pancreas. Following ligature of the suprarenal vein, antihypertensive therapy could be finished. For stabilization of blood pressure a noradrenaline application was necessary in descending dosage over a period of two days. The further postoperative course was without complications. The results of the urine catecholamine measurements and histological examinations confirmed the intraoperative diagnosis. An unidentified phaeochromocytoma is a vital threat for patients during surgery and anesthesia. Phaeochromocytomas are observed in patients suffering from Recklinghausen's disease (and other phacomatoses) in an above average incidence. Therefore, such a tumor should be excluded in these patients before elective surgery even if the patient does not show symptoms (asymptomatic phaeochromocytomas occur). The determination of catecholamines in 24 hour urine collections is an easy and specific diagnostic procedure and should be used in patients suffering from phacomatoses before elective surgery.

Adrenal Gland Neoplasms↗

PubMed2001

Comparative genomic in situ hybridization (cGISH) analysis on plant chromosomes revealed by labelled Arabidopsis DNA.

A new approach for comparative cytogenetic banding analysis of plant chromosomes has been established. The comparative GISH (cGISH) technique is universally applicable to various complex genomes of Monocotyledonae (Triticum aestivum, Agropyron elongatum, Secale cereale, Hordeum vulgare, Allium cepa, Muscari armenaticum and Lilium longiflorum) and Dicotyledonae (Vicia faba, Beta vulgaris, Arabidopsis thaliana). Labelled total genomic DNA of A. thaliana generates signals at conserved chromosome regions. The nucleolus organizing regions (NORs) containing the majority of tandemly repeated rDNA sequences, N-band regions containing satellite DNA, conserved homologous sequences at telomeres and additional chromosome-characteristic markers were detected in heterologous FISH experiments. Multicolour FISH analysis with repetitive DNA probes simultaneously revealed the chromosome assignment of 56 cGISH signals in rye and 61 cGISH signals in barley. Further advantages of this technique are: (1) the fast and straightforward preparation of the probe; (2) the generation of signals with high intensity and reproducibility even without signal amplification; and (3) no requirement of species-specific sequences suitable for molecular karyotype analysis. Hybridization can be performed without competitive DNA. Signal detection without significant background is possible under low stringency conditions. The universal application of this fast and simple one-step fluorescence banding technique for plant cytogenetic and plant genome evolution is discussed.

Arabidopsis↗

PubMed2000

[The upside-down stomach. Laparoscopic treatment is possible].

An upside-down-stomach, usually occurring in eldery patients describes an extreme case of paraesophageal hernia. Due to the possibility of life threatening complications there is an urgent need for surgical intervention. In 1998 three patients suffering from complete upside-down-stomach were treated by laparoscopic surgery at our hospital. Two of them received a hiatoplastic with fundo- and corpophrenicopexy. In one case we did a 360 degrees-floppy Nissen's-fundoplication. Perioperatively, one patient developed a left sided pneumothorax Long-term follow-up 6 months postoperatively in our out-patient department revealed unconspicuous clinical and gastroscopical findings and high patient satisfaction with postoperative outcome. Our case reports show the possibility of adequate operating on upside-down-stomach by means of laparoscopic surgery. Minimal invasive methods provide a good overlock on the operating field and are poor in complications when done by an experienced surgeon, so that patients may profit from comfort of laparoscopic surgery.

Adult↗

PubMed1999

[Acute cholecystitis--primary laparoscopic procedure].

The role of laparoscopic cholecystectomy on patients with histologically confirmed acute cholecystitis is still controversial. From January 1992 to December 1996, 228 cholecystectomies were performed for acute cholecystitis and a total of 104 patients were operated on conventionally and 124 patients underwent laparoscopic surgery. In a prospective study we compared the conventional with the laparoscopic technique. The results indicated that in 19 patients (15.3%) treated initially with the laparoscopic technique, a switch to laparotomy was required. The operating duration was lower for conventional cholecystectomy (75 min versus 95 min). However, surgical and nonsurgical complication rates were similar in both groups. The period of hospitalization was shorter in laparoscopic operations. According to these results we believe that laparoscopic cholecystectomy in patients with acute cholecystitis is a safe and effective procedure. The patients will benefit from the advantages of laparoscopic surgery without increased morbidity.

Acute Disease↗

PubMed1998

[Preoperative diagnosis in laparoscopic cholecystectomy: is intravenous cholangiography currently still justified?].

Laparocopic cholecystectomy requires essentially the safe exclusion of choledocholithias. The aim of this study was to compare the intravenous cholangiography and ERCP in addition to a basic program (case history, laboratory results ultrasound) with references to the diagnostic ability and therapeutic consequences in patients with choledocholithiasis. The results show, that the intravenous cholangiography not provides extra important informations after the case history, ultrasound and laboratory findings and therefore its general use is not justified. Instead of the intravenous cholangiography the preoperative ERCP should be performed generously if choledocholithiasis is suspected, especially because the ERCP offers the possibility to extract the stone.

Cholangiography↗

PubMed1996

Physical and topographical mapping among Triticeae chromosomes.

Three principal approaches have been used in our laboratory to analyze Triticeae genomes. (i) Synteny analysis: synteny among different Gramineae genomes was studied employing the elegant system of the Agropyron chromosome-induced deletion lines of wheat. Deletion mapping, predominantly of the homoeologous group 7 chromosomes, has led to the construction of a high density physical consensus map of wheat. The integration of wheat, barley and oat RFLP markers proves the colinearity between the wheat A-, B- and D-genomes, the H-genome of barley, and the E-genome of Agropyron. (ii) Light microscopic in situ techniques: the recent improvement of a drop technique for plant protoplasts was crucial for the sensitivity enhancement of fluorescence in situ hybridization (FISH), the efficient preparation of plant chromosomes for high resolution scanning electron microscopy, mapping of low-copy sequences, and comparative in situ hybridization. A tandemly amplified repetitive sequence element from microdissected barley chromosomes has enabled the karyotyping of Gramineae genomes in a single step. We have isolated and characterized members of this element family from other Triticeae species using PCR. The significant interspecific sequence differences were useful to identify single plant genomes, chromosomes and chromosome segments via post-hybridization washes under different stringency conditions. These sequences are also useful for simultaneous double or triple hybridization experiments in an attempt to localize new sequences on specific chromosomes or chromosome segments. The physical mapping of the Sec-1 locus has been refined on the satellite of chromosome 1R of rye, and the syntenic locus on barley chromosome 1H was identified. (iii) Physical mapping of rDNA sequences by high resolution electron microscopy: a method was developed for in situ hybridization and signal detection using high resolution field emission scanning electron microscopy and a backscattered electron detector. Colloidal gold particles were localized on chromosome structures resembling the 30 nm fibre. An rDNA probe was located in the secondary constriction and the highly compact adjacent regions of barley chromosomes.

Chromosome Mapping↗

PubMed1995

Repeated DNA sequences isolated by microdissection. I. Karyotyping of barley (Hordeum vulgare L.).

We report on microdissection, cloning and sequence, and Southern and fluorescence in situ hybridization (FISH) analysis of one moderately and one highly amplified repetitive DNA element, pHvMWG2314 and pHvMWG2315, respectively, isolated from barley (Hordeum vulgare L.) chromosome arm 3HL. The pHvMWG2315 sequence hybridizes to all 14 telomeric or subtelomeric regions of the barley chromosomes as determined by FISH. The 50 different hybridization sites that include intercalary signals allow the discrimination of all 14 chromosome arms and the construction of a kariotype of barley. The tandemly repeated subtelomeric element of 331 bp exists in all Triticeae species tested (H. vulgare, Agropyron elongatum, Secale cereale, Triticum tauschii, T. turgidum, and T. aestivum). It is AT rich (66%), exibits 84% sequence homology to subfragments of the D genome ¿specific¿ 1-kb element pAs1 of T. tauscii and 75% homology to interspersed genome-specific DNA sequence pHcKB6 from H. chilence. The repetitive sequence pHvMWG2314 is moderately amplified in barley and highly amplified in hexaploid wheat. The in situ experiments revealed no distinct signals on barley chromosomes, indicating a dispersed character for the sequence. The significance of the results for the identification of chromosomes and chromosome aberrations in FISH experiments are discussed.

Base Composition↗

PubMed1994

Comparison of genetic and physical maps of group 7 chromosomes from Triticum aestivum L.

We present a high density physical map of homoeologous group 7 chromosomes from Triticum aestivum L. using a series of 54 deletion lines, 6 random amplified polymorphic DNA (RAPD) markers and 91 cDNA or genomic DNA clones from wheat, barley and oat. So far, 51 chromosome segments have been distinguished by molecular markers, and 54 homoeoloci have been allocated among chromosomes 7A, 7B and 7D. The linear order of molecular markers along the chromosomes is almost identical in the A- B- and D-genome of wheat. In addition, there is colinearity between the physical and genetic maps of chromosomes 7A, 7B and 7D from T. aestivum, indicating gene synteny among the Triticeae. However, comparison of the physical map of chromosome 7D from T. aestivum with the genetic map from Triticum tauschii some markers have been shown to be physically allocated with distortion in more distal chromosome regions. The integration of genetic and physical maps could assist in estimating the frequency and distribution of recombination in defined regions along the chromosome. Physical distance did not correlate with genetic distance. A dense map facilitates the detection of multiple rearrangements. We present the first evidence for an interstitial inversion either on chromosome arm 7AS or 7DS of Chinese Spring. Molecularly tagged chromosome regions (MTCRs) provide landmarks for long-range mapping of DNA fragments.

Blotting, Southern↗