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Biomedical subjects

K Frank

Publications and source records attributed to K Frank.

At least 73 records · Page 4Linked to original sources
PubMed1990

The effect of fluoride on the resorption of dentine by osteoclasts in vitro.

Osteoclasts were isolated mechanically from bones of prehatch chicks and cultured on dentine for 24 or 39 h in medium without or with added sodium fluoride at concentrations of 0.15, 1, 15, or 30 mg/liter. Fixed and toluidine blue-stained specimens were examined by light microscopy and osteoclasts were counted, all cells were removed and resorption pits were counted. The dentine was then prepared for scanning electron microscopy (SEM) and pits located on a raster search using backscattered electron imaging. Stereophotogrammetric measurements were made of the depths, plan and true surface areas and volumes of pits, and the volume:area ratio and a three-dimensional form factor calculated for each. The presence or absence of a ring of demineralization around each pit was recorded. Pits with the same plan area were significantly (p less than 0.001) less deep in cultures containing 15 or 30 mg/liter NaF and the incidence of rings around pits was higher (controls 2.7%, 15 mg/liter 31.3%, 30 mg/liter NaF 39.7%). In one experiment, pits were larger in the specimen cultured with added 1 mg/liter NaF, but in a much larger series of 631 (251 in the control and 380 in the 1 mg/liter NaF cultures) pits measured, depths, volumes and volume:plan-area ratios were significantly lower (p less than 0.001), and rings round pits 2.5 times more common, in the fluoride-treated group. A complex interplay of stimulation of some cells in the culture with indirect stimulation of osteoclasts and direct inhibition of osteoclastic resorptive function may be operating at this concentration of fluoride. In vivo, therapeutic doses of sodium fluoride would be expected to act not only to increase the formation of osteoid but also to suppress osteoclastic activity.

Animals↗
PubMed1990

[Echogenic splenic lesions--incidence and differential diagnosis].

In order to estimate the incidence and clinical relevance of echogenic focal lesions in the spleen, 121,372 ultrasound investigations from seven laboratories were evaluated. Ninety-two cases with echogenic lesions in the spleen were reviewed (incidence: 3.2 to 14.2 of 10,000 patients). Differential diagnosis included neoplastic tumors (17.4%; five metastases, three lymphomas, seven hemangiomas, one lymphangiomatosis), vascular disorders (17.4%: bleeding, infarct) and inflammatory focal lesions (8.7%; abscess, calcifications). Follow-up studies showed no change in size and pattern in a further 17.4% of the lesions, indicating benign disorders. Thirty patients suffered from a malignant condition with splenic metastasis or lymphomas in eight cases. In a further five patients, it was possible to confirm echogenic hemangiomas. There are no specific echographic patterns which differentiate hemangiomas from malignant tumors.

Diagnosis, Differential↗
PubMed1990

[Endosonographic staging of rectal tumors].

Pre-operative staging was performed in 81 patients with rectal tumours by means of endorectal sonography. In 87% of cases (70 out of 81), the endosonographic findings corresponded with the histopathological appearance; the recognition of T0 and 1 tumours, which is important in deciding surgical procedures, was possible in 94% (51 out of 54). Differentiation between T0 and T1 tumours (i.e. between adenomas and carcinomas infiltrating the submucosa) was not possible. Five out of ten of T2 and 14 out of 16 T3 tumours were staged correctly. One T4 tumour was placed in too low a stage. A comparison of the echo structure of adenomas and carcinomas in 76 patients showed that 28 out of 43 adenomas (65%) have homogeneous echoes, while 24 out of 33 carcinomas (73%) showed inhomogeneous low intensity echoes.

Adult↗
PubMed1990

[The development of the assortment and requirements of the tissue bank of the District Institute for Blood Donation and Transfusion Leipzig].

Since the foundation of the tissue bank at the District Institute for Blood Donation--and Transfusion Service of Leipzig in 1966 the range of production and the assortment of nonvital tissue transplants has considerably increased. The amount of clinical establishments and their requirements is considerably increased, in which the realization of demands is not always possible without waiting periods. The main tissue conservation method is the cryo-drying. Besides the extreme cooling and cryo-preservation were used. Problems of transportation of cooled tissue conserves were discussed.

Freeze Drying↗
PubMed1989

Primary glucocorticoid receptor defect with likely familial involvement.

A 29-year-old woman with moderately elevated blood pressure and signs of hyperandrogenism (hirsutism and acne) but without typical Cushing's syndrome symptoms has been followed for almost 6 years. Steroid and glucocorticoid receptor studies indicated a primary glucocorticoid receptor defect. Elevated androgen values were of special interest. Clinical manifestation of hyperandrogenism seemed not to be proportional to the biochemical findings. Therefore, the possibility of a partial androgen receptor defect should also be considered.

Acne Vulgaris↗
PubMed1989

Endoluminal ultrasonic examination of sessile polyps and early carcinomas of the rectum.

The results of conventional endosonographic techniques in the assessment of early carcinomas and sessile polyps of the rectum have been unsatisfactory. We therefore developed a new technique in which the rectal cavity is filled directly with water. Using this technique, the anatomy of small rectal tumors is preserved and the layers of the rectal wall are easier to differentiate, especially with a 10-MHz scanner. The clinical results in 66 patients demonstrate that this new technique is very accurate in the preoperative staging of adenomas and T1-carcinomas of the rectum.

Carcinoma↗
PubMed1989

Endoluminal sonography in follow-up of rectal carcinoma.

Fourteen patients who had undergone local excision, anterior resection or low anterior resection for rectal carcinoma were examined by endoscopic ultrasonography. In two of three cases of local recurrent carcinomas, endoscopic sonography was superior to computed tomography in determining the depth of tumor infiltration. There were difficulties in differentiating scar tissue from local tumor formation when the mucosa appeared normal upon endoscopic examination. Only repeated follow-up examinations starting in the postoperative period, will allow a differentiation between scar tissue and local tumor recurrence.

Adenocarcinoma↗
PubMed1989

[New endosonographic examination technic for improving the assessment of small rectal tumors].

Conventional endosonographic techniques of examination in early carcinoma and sessile rectal adenoma have shown unsatisfactory results. We therefore fill the rectal cavity directly with water. Using this technique the anatomy of the rectal polyp is preserved, and the separate layers are easier to differentiate, especially when the 10-MHz scanner is used. The clinical results in 56 patients show an improvement concerning the preoperative staging especially in those tumors which are not palpable.

Carcinoma↗
PubMed1988

[Structure of the wall of the gastrointestinal tract: a comparative sonographic-morphologic study].

High frequency ultrasound can resolve the structure of the wall of the gastro-intestinal tract into three highly echogenic lines with poorly echogenic zones between them. Sequential removal of layers of the walls of fresh specimens of the gastro-intestinal tract showed the following correlation between the sonographic and histological findings: the innermost and outermost highly echogenic lines correspond to incident and exit echoes. The middle line corresponds with the sub-mucosa and the junctional zones of the mucosa/muscularis mucosa and sub-mucosa/muscularis propria. The intervening low echo lines correspond with the mucosa and muscularis propria.

Animals↗
PubMed1988

[Endorectal sonography in rectal cancer].

35 patients with rectal cancer were examined in a prospective trial by endorectal ultrasound. In 27 patients the sonographic diagnosis of tumour penetration was correct as compared with histologic findings, in 7 patients infiltration depth was overestimated, and in one case underestimated. In 21 resected specimens, examined postoperatively in a water tank with the same equipment, ultrasonic examination was correct in 17; in no case was the infiltration depth underestimated. The different technical approaches in local sonographic staging of rectal cancer are discussed.

Humans↗
PubMed1988

[Sonography of pancreatic carcinoma. Sonomorphology, diagnostic accuracy and tumor staging].

Ultrasonography was performed in 125 consecutive patients with clinically suspected carcinoma of the pancreas. The most important diagnostic criteria were reflectivity and echo amplitude, which were locally decreased in 71% (50/70) and increased in 27% (19/70) of the cancers. The echogenicity and reflectivity did not differ in four endocrine active tumors and adenocarcinomas. The diagnostic accuracy was 83% (101/122); in 3 patients ultrasonography failed to provide adequate information. Dilation of the biliary tree was found in 68% (43/50) of the carcinomas and dilation of the Wirsungian duct in 52% (32/58). There was some difficulty in differentiating between pancreatic carcinoma and chronic pancreatitis because the echogenicity is similar for both and inflammatory and neoplastic pancreatic processes are also present in both diseases. Although only 2-3 cm in diameter, 87% (7/8) of the carcinomas were already in the T3 stage. Angiography to evaluate resectability is unnecessary only when vascular encasement, extensive infiltration of peripancreatic fat, or tumor thrombus has been demonstrated sonographically.

Adenocarcinoma↗