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Biomedical subjects

G Alzen

Publications and source records attributed to G Alzen.

At least 19 recordsLinked to original sources
PubMed2006

[Assessment of bone density in children and adolescents by quantitative CT of one lumbar vertebra only].

AIM: The aim of this study was to determine whether measuring the trabecular bone density in one lumbar vertebra (L) instead of three has an effect on the assessment of bone density in children. MATERIALS AND METHODS: Bone density was measured in 70 patients (38 male, 32 female), ages 1 to 22 years (mean age 12.4, median 13 years) using a Somatom Balance Scanner (Siemens). The trabecular bone density was measured (1-cm slice, 80 kV, 81 mAs) in L1 through L3. RESULTS: The mean bone density in the lumbar vertebrae was 139.9 mg/ml calcium-hydroxylapatite per ml bone in L1, 133.9 in L2, and 131.7 in L3, and the mean of all three vertebrae was 135.2 mg/ml. Measurements in L1 were 4.7 mg/ml (standard deviation [SD] 4.7 mg/ml) above the mean value of the three upper lumbar vertebrae. The density in L2 was 1.3 mg/ml below the mean (SD 3.1 mg/ml). On average, L3 was 3.5 mg/ml below the mean (SD 4.6 mg/ml). This minor systematic deviation in the measurement values for the individual vertebrae from the mean value was so low that there was no statistical evidence for a deviation from an ideal regression line. CONCLUSIONS: When using an adequate technique, especially accurate analysis of the topogram (scout view) and the tomogram, measurement of the bone density of one lumbar vertebra provides satisfactory information regarding the trabecular bone density in children, but the values differ in the three upper lumbar vertebrae. The bone density of L2 is close to the mean of the upper three vertebrae. In the case of pathologic values or a pathologic trabecular pattern, three vertebrae should be measured.

Absorptiometry, Photon↗
PubMed2006

[Trabecular bone mineral density measured by quantitative CT of the lumbar spine in children and adolescents: reference values and peak bone mass].

PURPOSE: The aim of this study was to assess bone density values in the trabecular substance of the lumbar vertebral column in children and young adults in Germany from infancy to the age of peak bone mass. MATERIALS AND METHODS: We performed quantitative computed tomography (QCT) on the first lumbar vertebra in 28 children and adolescents without diseases that may influence bone metabolism (15 boys, 13 girls, mean ages 11 and 8 years, respectively). We also measured 17 healthy young adults (9 men, 8 women, mean ages 20 and 21 years). We used a Somatom Balance Scanner (Siemens, Erlangen) and the Siemens Osteo software. Scan parameters: Slice thickness 1 cm, 80 kV, 81 or 114 mAs. We measured the trabecular bone density and the area and height of the vertebra and calculated the volume and content of calcium hydroxyapatite (Ca-HA) in the trabecular substance of the first lumbar vertebra. RESULTS: Prepubertal boys had a mean bone density of 148.5 (median [med] 150.1, standard deviation [SD] 15.4) mg/Ca-HA per ml bone, and prepubertal girls had a mean density of 149.5 (med 150.8, SD 23.5) mg/ml. We did not observe a difference between prepubertal boys and girls. After puberty there was a significant difference (p < 0.001) between males and females: Mean density (male) 158.0, med 162.5, SD 24.0 mg/ml, mean density (female) 191.2, med 191.3, SD 17.7 mg/ml. The Ca-HA content in the trabecular bone of the first lumbar vertebra was 1.1 (med 1.1, SD 0.5) g for prepubertal boys and 1.1 (0.9, 0.4) g for prepubertal girls. For post-pubertal males, the mean Ca-HA content was 3.5 g, med 3.5, SD 0.5 g, and for post-pubertal females, the mean content was 2.8, med 2.7, SD 0.4 g. CONCLUSION: The normal trabecular bone mineral density is 150 mg/ml with a standard deviation of 20 mg/ml independent of age or gender until the beginning of puberty. Peak bone mass (bone mineral content) in the trabecular substance of the lumbar vertebral column is higher in males than in females, and peak bone density is higher in young female adults than in young male adults.

Absorptiometry, Photon↗
PubMed2005

[Sonography of the optical nerve -- experience in 483 children].

INTRODUCTION: In case of increased intracranial pressure (IICP), the inflow of cerebrospinal fluid widens the space between the optic nerve (ON) itself and the surrounding dura mater leading to the sonographic appearance of increased diameter of the ON. The purpose of the study was to gain clinical experience in children and to determine (a) the mean values for patients without proven IICP and (b) pathologic values of those with proven IICP. MATERIALS AND METHODS: Ultrasound of the optic nerve was performed in 483 children with symptoms consistent with IICP, comprising 287 males and 196 females at an age ranging from 4 days to 24 years with a mean age of 7.5 + 5.1 years. The measured diameter of the ON of both eyes and the morphologic criteria concerning nerve sheath and papilla were evaluated retrospectively. RESULTS: Most of the investigated patients (n = 466) had no IICP as confirmed by neurological examination, EEG, sometimes CCT and/or MRI and clinical follow-up. The typical morphological findings in patients with normal intracranial pressure (ICP) were a clear and longitudinally extended demarcation of the ON with a well-delimited nerve sheath and without prominent papilla. The mean diameter of the ON in patients with normal ICP was 3.4 mm + 0.7 mm. In 17 patients with proven IICP, the mean diameter of the ON increased to 5.6 mm + 0.9 mm. Typically, the nerve sheath was indistinguishable from the hypoechoic ON, often but not invariably associated with a prominent papilla. In patients with IICP, the diameter of the ON alone matches the diameter of the ON plus nerve sheath in patients with normal ICP. CONCLUSION: IICP was detected with a high sensitivity by ultrasound using the diameter and the morphological criteria of an indistinguishable nerve sheath. A diameter of more than 4.5 mm is definitely pathologic and requires further investigation. Prominence of the papilla is an unreliable criterion for acute IICP.

Adolescent↗
PubMed2004

X-linked lissencephaly with abnormal genitalia associated with renal phosphate wasting.

X-linked lissencephaly with abnormal genitalia (XLAG) is a rare disorder caused by mutations in the aristaless-related homeobox (ARX) gene. We report on the clinical data of a boy with a 1-bp deletion (790 delC) resulting in a frame shift in the ARX gene and prolonged survival until age 18 months. Similar to other patients, the boy showed postnatal microcephaly, hypothalamic dysfunction, intractable neonatal seizures, and chronic diarrhoea. In addition, he suffered from exocrine pancreatic insufficiency and renal phosphate wasting became apparent from age 5 months, both of which have not been described previously in XLAG. This allows us to speculate that the phenotype of XLAG is more complex than hitherto known and may include renal phosphate wasting which might not have been observed in other patients due to early death.

Abnormalities, Multiple↗
PubMed2002

[Solid-pseudopapillary tumors in childhood].

We report on fife female patients with solid pseudopapillary tumors of the pancreas. The tumors are extremely rare in children. They occur mainly in adolescent and young adult females. The tumors are neoplasms of low malignancy with infrequent metastases, for instance, in the liver or the peritoneum. Although the tumors had reached a large diameter, all of them underwent complete tumor resection. After that the patients have a very good prognosis. Thus, so it is important to distinguish solid-pseudopapillary tumors from other tumors of the pancreas.

Child↗
PubMed2002

Esophageal foreign bodies: removal of the new euro coins with a magnet tube.

AIM OF THIS STUDY: We use a magnet tube to extract esophageal coins. It is smaller than the Foley balloon catheter and easier to handle than a forceps. We present the magnet tube maneuver and investigate whether the new euro coins can be removed with a magnet. METHOD: We take radiographs of coins and measure the adhesive force of the magnet and compare with the 10 Pfennig German coin which we most often removed successfully from the esophagus. RESULTS: The 1, 2, and 5 euro cent pieces are magnetic and can possibly be removed with a magnet tube. The non-magnetic pieces can be identified based on the rim and size. DISCUSSION: When an esophageal foreign body is not round and smooth like a coin, the fluoroscopic guided procedure becomes more risky with respect to mucosal injury. When a large object is stuck in the esophagus for more than 24 hours, an endoscopy must be considered to rule out any severe damage to the esophageal wall.

Child↗
PubMed2000

[Pathophysiology, diagnosis and therapy of three congenital dacryocystoceles].

BACKGROUND: Congenital dacryocystocele has been rarely described in German literature. Congenital obstruction and distention of the lacrimal sac makes it necessary to differentiate for various causes. PATIENTS AND METHODS: Three infants had congenital dacryocystocele. The diagnosis was made by sonography and was established by probing the lacrimal duct and nasal endoscopy that showed a white prominent tumor below the lowest conch. RESULTS: Directly after endonasal and canalicular opening of the dacryocystocele clear liquid with white detritus drained, and the swelling decreased. No further procedure was needed. CONCLUSION: The diagnosis of dacryocystocele can be made by inspection, probing the lacrimal duct, ultrasound and nasal endoscopy. If probing of the lacrimal duct could not easily open the Hasner's membrane, endonasal opening can be performed. The cooperation with an ear-nose-throat specialist could lead to the diagnosis of dacryocystocele and sufficient treatment without the need for any further radiological examinations.

Dacryocystitis↗
PubMed1998

[Lipoma of the corpus callosum in a newborn infant: misinterpretation of cranial ultrasound by coincidence with thrombocytopenia].

Among the very rare intracerebral lipomas, those of the corpus callosum are the most frequent. Due to the advanced technology and the frequent use of ultrasonography these lesions are diagnosed more and more often. A female neonate was admitted to our hospital because of a progressive thrombocytopenia. Pregnancy was complicated by an autoimmune thrombocytopenia of the mother. While there were no remarkable findings on clinical presentation, a sonogram of the brain revealed an area of increased echogenicity in the midline which was interpreted as an intracerebral hemorrhage. In absence of any respective clinical signs a magnet-resonance-tomography of the brain was performed leading to the hypothesis of a lipoma of the corpus callosum (LCC) that could be verified by a densitometry in a cranial computer tomography (CT). Obviously, the initially performed sonogram was misinterpreted as an intracerebral hemorrhage due to the coincidence with the thrombocytopenia. At last the discrepancy of clinical and ultrasonographical findings led to the diagnosis by magnet-resonance-tomography and CT scan. Knowledge of the typical sonographic appearance of an LCC may be helpful for the differential diagnosis of this rare lesion even in fetal ultrasound.

Brain Neoplasms↗
PubMed1997

[Digital subtraction angiography with carbon dioxide using a new gas dosage system].

PURPOSE: The clinical evaluation of digital subtraction angiography with carbon dioxide using a newly developed low-tech CO2 dosage and injection system. METHOD AND PATIENTS: The hand-held system (CO2 angio set) consists of a dosage chamber in connection with a special stopcock to apportion the gas. By optimising injection volume and pressure steady gas flow characteristics are approximated. A safety design prevents unintentional gas injection. CO2 arteriographies were performed on 185 patients. Main indications were renal insufficiency and a history of adverse reactions to iodinated contrast media. In patients with femoral cannula access, catheterless reflux angiography was performed. RESULTS: The injection system provided complete and coherent visualisation of the abdominal aorta, visceral, pelvic, and lower limb arteries via catheter (71 cases) or via femoral cannula using reflux technique (114 cases). Stenoses, occlusions, and collaterals were assessable. Employing the gas reflux over the aortic bifurcation bilateral run-off studies up to the calf trifurcation were performed via unilateral femoral cannula. Use of a dedicated stacking software improved image quality of distal femoral, popliteal and calf arteries. CONCLUSION: The CO2 management system allows adequate imaging of the arteries below the diaphragm. Ease and safety of use and low costs are advantageous.

Angiography, Digital Subtraction↗
PubMed1997

Thoracic sequelae after surgical closure of the patent ductus arteriosus in premature infants.

Thirty-six children (median chronological age 6 years 1 month) who had undergone surgical closure of a patent ductus arteriosus through a left posterolateral thoracotomy in the neonatal period (median gestational age 32 weeks) were investigated prospectively with respect to anatomical and functional changes of the chest. At follow-up examination, residual or recurrent patent ductus arteriosus was not observed. Three patients had chronic bronchial obstruction. Two patients showed pathological musculoskeletal thoracic sequelae that did not require any treatment at the time of follow-up; persistence of immediate postoperative left phrenic palsy (n = 1) and thoracic scoliosis (n = 1). Twenty of the 27 patients in whom chest X-ray was performed had minor radiological skeletal anomalies in the form of rib deformation or fusion related to the thoracotomy, lesions which have a potential to induce thoracic scoliosis. Left shoulder elevation at chest X-ray and isolated left arm dysfunction at clinical examination were not observed. Despite the low incidence of scoliosis and the absence of left arm dysfunction observed at mid-term follow-up in our series, the incidence of minor rib deformations with a potential to induce severe anomalies such as scoliosis should motivate late follow-up examination at adolescence to definitively assess the prevalence of thoracic sequelae after surgical closure of the patent ductus arteriosus in premature infants.

Bronchial Diseases↗
PubMed1996

Inflammatory reaction and capillary leak syndrome related to cardiopulmonary bypass in neonates undergoing cardiac operations.

We studied the inflammatory reaction related to cardiopulmonary bypass in 24 neonates (median age 6 days) undergoing the arterial switch operation for simple transposition of the great arteries, with respect to the development of postoperative capillary leak syndrome. Complement proteins, leukocyte count, tumor necrosis factor-alpha, and histamine levels were determined before, during, and after cardiopulmonary bypass. Additionally, protein movement from the intravascular into the extravascular space during cardiopulmonary bypass was assessed by the measurement of plasma concentrations of proteins with molecular weights ranging from 21,200 to 718,000. Capillary leak syndrome developed in 13 of the 24 neonates. Patients with capillary leak syndrome, as compared with those without, had preoperatively higher C5a levels (C5a, 3.0 +/- 0.6 microgram/L vs 0.9 +/- 0.2 microgram/L) (mean +/- standard error of the mean) (p < 0.05) and higher leukocyte counts (leukocytes, 17.9 +/- 2.1 X 10(3) cells/ml versus 11.7 +/- 0.8 X 10(3) cells/ml) (p < 0.05), suggesting in these neonates a preoperative inflammatory state. Preoperative clinical and operative data were identical in both patient groups. Before cardiopulmonary bypass, serum protein concentrations were similar in all patients. Ten minutes after institution of cardiopulmonary bypass, protein concentrations fell to significantly lower values in patients with capillary leak syndrome than in those without: albumin (19% +/- 1.5% vs 30% +/- 6% of the prebypass value, p < 0.05), immunoglobulin G (17% +/- 1.5% vs 29% +/- 5.5%, p < 0.001), and alpha 2-macroglobulin (15% +/- 1.2% vs 25% +/- 4%, p < 0.02). During cardiopulmonary bypass, albumin concentrations remained significantly lower in patients with capillary leak syndrome than in those without, whereas hematocrit values were similar in both groups. During cardiopulmonary bypass, patients with capillary leak syndrome also had lower concentrations of complement proteins C3 and C4 but not C1 inhibitor. C3d/C3 ratio and C5a levels were similar in both patient groups. In contrast, histamine liberation during cardiopulmonary bypass was significantly more pronounced in patients with capillary leak syndrome than in those without (725.2 +/- 396.7 pg/ml vs -54.1 +/- 58.4 pg/ml, p < 0.05). Tumor necrosis factor-alpha levels after protamine administration were also significantly higher in patients with capillary leak syndrome (38.1 +/- 10.0 pg/ml vs 15.3 +/- 3.4 pg/ml, p < 0.05). Leukocyte count during and after cardiopulmonary bypass was similar in both patient groups. This study demonstrates increased protein leakage as early as 10 minutes after initiation of.

Acute-Phase Reaction↗