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Biomedical subjects

H Vogel

Publications and source records attributed to H Vogel.

At least 19 recordsLinked to original sources
PubMed2024

Phylogenomic reconstruction of Cryptosporidium spp. captured directly from clinical samples reveals extensive genetic diversity.

Cryptosporidium is a leading cause of severe diarrhea and mortality in young children and infants in Africa and southern Asia. More than twenty Cryptosporidium species infect humans, of which C. parvum and C. hominis are the major agents causing moderate to severe diarrhea. Relatively few genetic markers are typically applied to genotype and/or diagnose Cryptosporidium. Most infections produce limited oocysts making it difficult to perform whole genome sequencing (WGS) directly from stool samples. Hence, there is an immediate need to apply WGS strategies to 1) develop high-resolution genetic markers to genotype these parasites more precisely, 2) to investigate endemic regions and detect the prevalence of different genotypes, and the role of mixed infections in generating genetic diversity, and 3) to investigate zoonotic transmission and evolution. To understand Cryptosporidium global population genetic structure, we applied Capture Enrichment Sequencing (CES-Seq) using 74,973 RNA-based 120 nucleotide baits that cover ~92% of the genome of C. parvum. CES-Seq is sensitive and successfully sequenced Cryptosporidium genomic DNA diluted up to 0.005% in human stool DNA. It also resolved mixed strain infections and captured new species of Cryptosporidium directly from clinical/field samples to promote genome-wide phylogenomic analyses and prospective GWAS studies.

Cryptosporidium↗
PubMed1979

[Radiation risks and gonadal exposure in radiodiagnosis (author's transl)].

Radiation risk is estimated from the values on radiation risk of the International Council on Radiation Protection and from our own measurements. According to these, 1 malignant growth induced by radiation is found in about 160,000 urograms, 300,000 contrast enemata or 500,000 contrast meals. In radiodiagnosis of the central nervous system the values for carotid angiograms is about 60,000, for vertebral angiograms about 16,000, for computer tomography about 50,000 and about 500,000 examinations of the skull in two planes. A mutation-induced deformity due to radiation occurs in about 4,300--26,000 colon contrast enemata, about 43,000 to 280,000 contrast meals and about 41,000 respectively 14,000 urograms in men and women in the reproductive years.

Abnormalities, Radiation-Induced↗
PubMed1979

Electrostatic interactions at charged lipid membranes. Electrostatically induced tilt.

The changes in bilayer structure induced by surface charges in the case of an ionizable lipid were studied by X-ray diffraction, Raman spectroscopy, and film-balance measurements. With increasing surface charge in the ordered phase, the X-ray results show a decrease in bilayer thickness, whereas the hydrocarbon chain packing stays essentially constant, the Raman data signify that the internal chain ordering does not change, and the monolayer studies show a lateral expansion of the bilayer. These results are interpreted in terms of a tilt of the chains caused by the surface charges on the polar heads. The tilt angle between the direction of the chains and the bilayer normal is obtained by a detailed theoretical evaluation. The tilt allows for a better understanding of the electrostatically induced shift of the phase transition temperature and of the shift induced by the binding of water in the case of lecithin in contrast ethanolamine.

Hydrogen-Ion Concentration↗
PubMed1979

The rotational diffusion of cytochrome b5 in lipid bilayer membranes. Influence of the lipid physical state.

A derivative of the integral membranes protein, cytochrome b5, has been prepared in which the native heme group has been replaced by the structurally similar rhodium(III)-protoporphyrin IX. This metalloporphyrin has a finite triplet yield with a single exponential decay time of 22 microsecond in water. After insertion of the metalloporphyrin into the protein, its triplet-state decay becomes strongly nonexponential with at least three equal amplitude components with time constants varying over a range of 100. The derivatized protein has been incorporated into unilamellar liposomes prepared from dimyristoyllecithin, and the rotational diffusion of the protein in the lipid bilayer has been studied at temperatures above and below the lipid phase transition temperature via triplet absorbance anisotropy decay. The anisotropy decay curves are biphasic both above and below the lipid phase transition. The rotational diffusion constant is found to be 2.4 X 10(5) s-1 at 35 degrees C, and 1.1 X 10(4) s-1 at 10 degrees C, both being calculated from the fast decay component. The ratio of the limiting anisotropy to the initial anisotropy is 0.6 at both temperatures. This implies a cone of restricted motion of 34 degrees for the protein in the bilayer.

Animals↗
PubMed1979

[Radiographic findings after duodenal surgery (author's transl)].

A gastroduodenostomy as part of partial gastric resection may change function and morphology of the duodenum in a typical fashion. End to side anastomosis may produce a blind pouch. An end to end anastomosis may lead to postanastomotic dilatation, which may mimick a duodenal bulb (a so called "neo -- or pseudobulb"). Abnormal duodenal peristalsis with atony may follow vagotomy, pyloroplasty, gastroduodenostomy or excisional duodenal biopsy and may thus result in functional obstruction. A blind loop syndrome may develop after bypass procedures for duodenal stenosis.

Common Bile Duct↗
PubMed1979

[Exceptional diabetic arthropathy of the foot (author's transl)].

The osteopathy of the foot is a rare complication of diabetes mellitus. It is seen in the distal parts mostly. The arthropathy ("Charcot-joint") is even more rare, and is regularly combined with a neuropathy. The roentgen signs of the "diabetic foot" are demonstrated, as there are osteoporosis, iuxta-articular cortical defects, osteolysis of the bone ends, bone destruction and reconstruction, periost reaction and sklerosis of the bone shafts.

Diabetes Complications↗
PubMed1979

[Pseudotumors after gastric and small bowel surgery (author's transl)].

After surgery of the upper gastrointestinal tract operation induced alterations with tumoraspect (pseudotumors) must be separated from malignomas. There are characteristic pseudotumors after the different operations that can be identified during the barium meal. If an early postoperativ roentgenexamination is available, the differential-diagnosis may be possible even in otherwise doubtful cases.

Diagnosis, Differential↗
PubMed1979

[Radiation-risk in roentgendiagnostic of the gastro-intestinal tract (author's transl)].

The probability to induce leukemia or malignoma by roentgenexamination of the gastrointestinal tract is quite small. Basing on riskestimations of the ICRP and own measurements, the probability is about 1:25,000 in angiography. For x-ray examination of the stomach-duodenum, the small bowl, and the colon the radiation risk is approximatively 1:300,000 to 1:800,000. The probability to provoque radiation induced mutations, manifesting themselves in future children or grandchildren, is quite similair for male patients. On the other hand the risk for future children and grandchildren of female patients is a bit higher. An exception is the roentgenexamination of the colon, because direct exposure of the testes is in general inevitable.

Angiography↗
PubMed1979

[Bile-duct-stenosis after operation of the common bile-duct with T-tubes (author's transl)].

3 stenosis of the bile duct were observed in a postoperative study out of 25 patients, who underwent operations of the bile-duct-system and had T-tubes. These patients had no complaints. One patient had a reanastomosis of the bile duct, the stenosis was in the area of the anastomosis. The T-tubes of 2 patients were postoperatively under traction, which might have favoured the stenosis. The possibilities of intravenous cholangiography and endoscopic-retrograde cholangiography are discussed.

Biliary Tract↗
PubMed1979

[X-ray diagnosis and the clinical aspects after pancreatectomy].

11 patients (three women) were examined 7 month to 12 years after total pancreatectomy. There were found differences of--34% to +23% between bodyweight and ideaweight. Three patients with a bodyweight less than 75% of the idealweight died, steatorrhea (8--19 g/die), bloodsugar oscillation in the 24 h-profile (40--820 mg%) and an intrinsic-factor-non-responsive vitamin B12-malabsorption without megaloblastic anemia. The roentgenexamination permitted a classification of the upper gastrointestinaltract in a type similar to B II or B I resection and a type with Y- Roux anastomosis for bilarydrainage.

Adenocarcinoma↗
PubMed1979

[Roentgen examination after oesophageal surgery (author's transl)].

Sutureinsufficiency has to be sought postoperatively. Later, tumors, passage disturbances and reflux must be looked for. Antirefluxsurgery with fundoplication may lead to a roentgenmorphology with tumoraspect. After transoesophageal sclerosis of varices passage disturbances and perforations may be seen. After perforations by endoscopic procedures the oesophageal roentgen examination with water-soluble substances completes the clinical surveillance.

Esophageal Neoplasms↗
PubMed1979

[Duplications of the gastro-intestinal tract (author's transl)].

Duplications of the stomach, small and large bowel are rare. In cases of communication with the lumen of the GI-tract, a reliable diagnosis can be made by radiography. Without direct communication these duplications present as fluid filled cystic mass lesions and therefore are difficult to specify radiographically.

Adolescent↗
PubMed1979

[Roentgendiagnostics of suture insufficiency and fistulation after operations of the gastro-intestinal tract (author's transl)].

The early roentgen examination permits the recognition of postoperative complications. Direct and indirect signs of suture insufficiency may be observed. An insufficiency can be proven by oral administration of watersoluble contrast substances or by extern filling of the fistula. The most frequent indirect sign is the extraintestinal air in constant position. Sonography and roentgen diagnostics complete each other, computer tomography may give similar results.

Contrast Media↗
PubMed1979

[Roentgenmorphology of the upper stomach after prophylactic reflux surgery (author's transl)].

The combination of vagotomy, of proximal and of total gastrectomy with antireflux-surgery can lead to a characteristic roentgenmorphology of the lower esophagus and the upper stomach. The fundoplication or hemifundoplication may have a tumorlike shape, may open up or may slide down. The knowledge of the preceding operation and of the symptoms allows a correct interpretation of the x-ray findings in most cases.

Deglutition Disorders↗
PubMed1979

[Computed tomography of the trunk in children (author's transl)].

So far whole body CT has not yet been used very often in children. The main reason for this are patient-related factors which impair the recognition of details on the scans such as frequent lack of intra abdominal fat tissue, and so called movement artefacts. The search for tumors is the predominent indication for CT in children. The advantages of CT are discussed and the authors' own measurements of radiation exposure are given.

Abdomen↗