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Biomedical subjects

P Meister

Publications and source records attributed to P Meister.

At least 19 recordsLinked to original sources
PubMed2000

Refinement of velopharyngoplasty in patients with cleft palate by covering the pharyngeal flap with nasal mucosa from the velum.

The velopharyngoplasty performed using the popular Sanvenero-Rosselli method improves the speech quality of patients with cleft palate suffering from persistent velopharyngeal insufficiency despite successful closure of the hard and soft palates. However, often a relatively narrow pharyngeal bridge results due to healing not only by granulation and scar contraction, but also due to the insertion of the inferior tip of the flap into a narrow bed. Elevation of two velar flaps with nasal mucosa to cover the exposed muscular undersurface of the pharyngeal flap produces a broader recipient bed into which the pharyngeal flap can be spread. The speech quality of 27 patients treated with this modified method (group B) was compared with that of 27 patients without this modification (group A). Eight weeks after velopharyngoplasty (followed by uneventful wound healing) the speech quality of group B was significantly better than that of group A (p<0.03 MannWhitney U-test). This difference was even more evident when comparing the preoperative with the postoperative speech quality (p<0.005). Thus, covering the exposed muscular layer of the pharyngeal flap with nasal mucosa of the velum is an important modification of velopharyngoplasty for the improvement of speech quality.

Adolescent↗
PubMed1999

[Hyalinizing spindle cell tumor with giant rosettes. Case report with immunohistochemical characterization].

This is a case of a 46-years-old male patient with a long-standing history of lower abdominal complaints. A 6-cm measuring tumor was detected by CT and subsequently surgically removed. Classification of this tumor and prognosis was problematic in frozen section and paraffin-embedded material, including immunohistochemical studies. The immunohistochemical findings were compatible with myofibroblastic differentiation of tumor cells. The histologic pattern resembled a "hyalinizing spindle cell tumor with giant rosettes" as recently published. Even if there were certain discrepancies in the immunohistochemical findings in our case, we also recommended treating this tumor as a low-grade sarcoma. The malignancy was also supported by marked proliferative activity demonstrated by MIB 1/KI 67 expression in numerous tumor cells. Finally, it has not yet been determined whether the hyalinizing spindle cell tumor is a pattern associated with a certain cellular differentiation or a pattern common to several mesenchymal tumor types.

Abdominal Neoplasms↗
PubMed1999

Psychotropic drug prescription in a psychiatric university hospital.

A retrospective survey on drug prescription over a one-year period (1989) in 1083 patients (48.3% of whom were male) hospitalized in a psychiatric university hospital in Switzerland and a 35-day prospective study (1992) on the prescription of "as needed" (prn) medication in a closed and an open ward were carried out. Their aim was to establish a basis for a monitoring of prescription habits and for pharmacoeconomic considerations. In the retrospective study, 48.3% of the patients were male. The mean duration of hospitalization of the patients was 47.0 +/- 68.1 days (mean +/- s.d.). Only 11 out of the 1083 patients (1%) were without psychotropic medication. The mean (+/- SD) number of drugs/day the patients were prescribed was 4.6 +/- 2.8, including 3.2 +/- 1.7 psychotropic drugs. Patients suffering from schizophrenia (67 d) or from unipolar depression (67.4 d) were hospitalized for the longest periods. Antipsychotics (67.5% of the patients) were the most frequently prescribed psychotropic drugs, followed by anxiolytics (42.2%), antidepressants (28.3%), hypnotics (31.4%) and mood stabilizers (7.1%). Antiparkinsonian agents accounted for 4.6% of all prescriptions. Levomepromazine, haloperidol (30.9% of all patients) and clotiapine were the most often prescribed neuroleptics, and clozapine was administered to only 6.4% of all patients. Among the antidepressants, maprotiline (11.9% of all patients) was more frequently prescribed than the classical tricyclic antidepressant amitriptyline, while the only available SSRI fluvoxamine and MAO inhibitors were rarely used. The most frequently prescribed anxiolytics were clorazepate (28.2% of all patients), lorazepam, bromazepam, and prazepam. Among the hypnotic drugs, chloral hydrate (11.5%) was more frequently administered than the first-ranking benzodiazepine flunitrazepam (7.8%). In the prospective study, 97% and 77% of the patients (n = 55) of the closed (n = 29) and of the open ward, respectively, were prescribed "as needed" (prn) drugs. However, only 71 and 80%, respectively, of these patients finally received the drug. The frequency of prescription was 34.9% for neuroleptics, 15.1% for anxiolytic drugs, 8.2% for non-benzodiazepine hypnotics and only 2.1% for benzodiazepine hypnotics. The most frequently prescribed neuroleptic drug was clotiapine (18% of all patients), but finally, only 29% of the prescribed doses were administered. Studies of this type are biased by the fact that local habits of prescription do not allow generalisation of the findings. Such surveys should be carried out more frequently and simultaneously in different centers. Critical comparisons could help to optimize treatment.

Adult↗
PubMed1998

[Spindle cell tumors and tumor-like changes of the prostate and surrounding tissue].

Spindle cell lesions of the prostate and surrounding tissues include mesenchymal and epithelial tumors and tumorlike lesions, such as postoperative spindle cell nodules (PSN) and pseudosarcomatous fibromyxoid tumors (PFMT). PSN and PFMT are possibly related fibroblastic and myofibroblastic proliferations respectively. However, they may be misinterpreted as sarcomas. PSN typically are detected incidentally several weeks or months after urological procedures such as cystoscopy. PFMT only rarely reveals a urological history, however, reaching back for several years; here, more often there is a clinical presentation with dysuria and/or hematuria. Important for the differential diagnosis of PSN and PFMT or sarcomas is not only a histological examination, including immunohistochemistry, but also a close clinicopathological correlation. Nevertheless, in some cases it may be impossible to reach a final diagnosis.

Carcinoma↗
PubMed1998

[Myofibroblasts. Review out outlook].

When studying inflammation and wound healing, peculiar fibroblasts with ultrastructural similarities to smooth muscle cells were described by a group of pathologists associated with Guido Majno (GM) and Giulio Gabbiani (GG), subsequently called myofibroblasts. Similar cells were also found later in human granulation tissue, palmar fibromatosis and in stromal reactions with invasive cancers. Their identification was facilitated by immunohistochemical methods. Some neoplastic cells, for instance in MFH, also revealed characteristics compatible with myofibroblasts. Myofibroblasts are conceived of as modulated fibroblasts. Cytokines may serve as mediators for activation and contractile modification of fibroblasts. In this context monitoring of a tumor-like overproduction of myofibroblasts or an underproduction with non-union of wounds might also be feasible. Moreover, better understanding of the role of myofibroblasts concerning the transition from in situ carcinomas into invasive growth may have therapeutic perspectives. Myofibroblasts apparently not only show a temporary existence in disease, but also can be found under normal conditions in several regions, such as the skin, periodontal ligaments, or pulmonary septa.

Cell Transformation, Neoplastic↗
PubMed1998

[Acquired, cystic kidney disease in chronic dialysis patients: a retrospective study of 125 autopsies. 1: Cysts].

In acquired cystic kidney disease cysts develop in kidneys with impaired excretory function. Bleeding, cyst infection and a possible relation to kidney cell carcinoma resulted in an interdisciplinary concern about this disease. Kidney tissue slides from 125 autopsies of dialysis patients were studied. Of totally 967 cysts, 52% were lined by a cuboidal epithelium, with either clear or eosinophilic cytoplasm; 34% showed a flat epithelium. Multilayered epithelium was present in 8.3% and bleeding stigmata in 5.3%. Cyst counts rose with duration of dialysis, with a higher average cyst count in men. There was no correlation between cysts and (1) age, at the time of death of at the beginning of dialysis, (2) type of renal disease, (3) blood group, (4) body weight, (5) coronary heart disease, and (6) diabetes mellitus. More studies on the development of cysts, parameters of cyst formation and complications are necessary, as they are the basis for the interpretation of new imaging techniques, as well as, for a clinical risk assessment.

Animals↗
PubMed1998

[Acquired cystic kidney disease in patients on long-term dialysis: a retrospective study of 125 autopsies. Part 2: tumors].

The possible relation of acquired cystic kidney disease to renal cell carcinoma resulted in an interdisciplinary concern about this disease. Kidneys from 125 autopsies of dialysis patients were studied. Twenty-four of the patients had tumors. Beside four renal adenocarcinomas and two urothelial carcinomas, incidental small tumor nodules were described in 15.1%. Men had more nodules than women. Patients with nodules had a higher average cyst count, often with multi-layered epithelium. There was no difference in age or time of dialysis. This suggests a factor which mediates cyst and tumor proliferation, independent from the time of dialysis. With the improvement in imaging techniques, an increasing number of small renal tumors will be found. Further studies are necessary to evaluate the risk of small kidney cell tumors and their association with acquired cystic kidney disease.

Aged↗
PubMed1998

[Cutaneous and subcutaneous soft tissue tumors].

Superficial, especially cutaneous soft tissue tumors deserve attention because of their special biology, often with better prognosis than their deep counterparts. This fact also has been considered in the TNM Classification/UICC, as well as in the Typing of Soft Tissue Tumors/WHO.-Basically all types of soft tissue tumors can also be found in subcutaneous and cutaneous localisation. Dermatofibrosarcoma protuberans, however, is a typical superficial tumor involving cutis and frequently the superficial subcutis. Superficial leiomyosarcoma and atypical fibroxanthoma are examples of sarcomas, which in spite of histological criteria, which generally are associated with high grade malignancy, behave as low grade malignant tumors, i.e. chiefly with risk of recurrency albeit negligible risk of metastases. Angiosarcoma and epitheloid sarcoma, on the other hand, may also metastasize, even if restricted to the cutis. Here histological criteria as numerous mitoses, cellular atypia and tumor necrosis, may additionally influence the prognosis. In conclusion it is evident that exact tumor classification is the basic requirement for an optimal, prognosis-adapted therapy. Prerequisite, however, is a precise clinico-pathological correlation to understand the biology of the different tumor entities.

Hemangiosarcoma↗
PubMed1997

Native pulmonary muscular proliferation.

Four cases with native pulmonary muscular proliferation (NPMP) are reported. The etiology of this rare condition is unknown. A hamartomatous process is discussed. In spite of its rarity the correct diagnosis of this condition is important. Both clinically and histologically in transbronchial biopsies, NPMP may be mistaken for pulmonary lymphangioleiomyomatosis (PLAM). Distinction of these 2 conditions is adamant, as PLAM has a poor prognosis, and, moreover may be associated with general disease, as with tuberous sclerosis. Whereas the typical distribution of more mature desmin positive muscle cells in a dense center core and more immature desmin negative radiating peripheral muscle cell proliferation with fascicular pattern in NPMP may be recognized in open lung biopsy, these differences may not become evident in small transbronchial biopsies. Immunohistochemical methods play an important role in the differential diagnosis--as with PLAM estrogen and progesterone receptors may be expressed and, most importantly, the reaction of the HMB45-antibody appears consistently positive in muscle cells of PLAM, while negative with NPMP. Thus, recognition of this clinically innocent disease is also possible in small tissue particles.

Actins↗
PubMed1996

[Sclerosing adenosis of the prostate. Carcinoma simulation].

Sclerosing adenosis of the prostate is a benign lesion, which was not recognized until a few years ago. As in sclerosing adenosis of the breast, a background of various hyperplastic changes is commonly also present in the prostate. An incidence of 2.8% was reported in one series of resected hyperplastic prostatic glands. As demonstrated in this case report, the main problem lies in the differential diagnosis between sclerosing adenosis and highly differentiated adenocarcinoma of the prostate. Histological diagnosis of sclerosing adenosis based on routine HE sections is supplemented by immunohistochemical methods. Important diagnostic criteria of sclerosing adenosis are the presence of basal cell differentiation, which is demonstrated by cytokeratin 903, and signs of possible myoepithelial differentiation, with expression of S-100 and/or smooth muscle actin. These antibody expressions are lacking with in the presence of adenocarcinoma of the prostate. Nevertheless, in a small number of cases this differential diagnosis remains impossible, even after the application of immunohistochemical methods. Further studies are needed to shed some light on the relations between sclerosing adenosis, atypical adenomatous hyperplasia and adenocarcinoma of the prostate. So far, there appears to be no evidence of a direct relationship between sclerosing adenosis of the prostate and an elevated risk of carcinoma.

Adenocarcinoma↗
PubMed1996

[Fibroepithelial polyp of the kidney pelvis].

Benign fibroepithelial polyps of the renal pelvis are rare. Because of suspected malignancy in imaging procedures an ureteronephrectomy was carried out in the reported case. Histology, however, yielded no evidence of malignancy. The diagnosis of benign fibroepithelial polyp was entertained. It remains an open question whether the pathologic changes represent a hamartoma or a reactive postinflammatory process, revealing primitive myxoid stroma within the polypous portion and increasing fibrosis with diffuse submucosal involvement of the ureteral basis.

Diagnosis, Differential↗
PubMed1996

Structural aberrations of chromosome 6 in three uterine smooth muscle tumors.

Clonal karyotypic alterations of chromosome 6 in three uterine smooth muscle tumors are reported. In all cases an apparently identical breakpoint on the short arm of chromosome 6 was found. Two cases displayed the histologic features of cell-rich myomas with severe nuclear atypia but no clear evidence for malignancy. The remaining case was a primary uterine leiomyosarcoma of an 80-year-old patient showing an apparently balanced reciprocal chromosomal translocation, t(1;6)(p32-33;p21.3), as the sole karyotypic abnormality. This type of aberration has not been reported before in leiomyosarcomas. Because of the nuclear atypia in the other myomas with a breakpoint involving the short arm of chromosome 6 we feel that this cytogenetically recognizable but rare subgroup of uterine smooth muscle tumors warrants a careful clinical follow-up.

Adult↗
PubMed1996

Malignant fibrous histiocytoma: histomorphological pattern or tumor type.

During the past years MFH has obviously been used as a diagnostic waste basket for hard to classify tumours of all kinds. Immunohistochemistry revealed insights into cellular differentiation of neoplastic proliferations, also raising new questions because of unexpected antigen expression, as, for instance, cytokeratins in MFH. Thus, a number of tumours originally diagnosed as MFH could be reclassified, i.e., as leiomyosarcoma, melanoma or anaplastic carcinoma. Nevertheless, there remain a certain number of sarcomas which lack any evidence of special cellular differentiation. These proliferations of primitive mesenchymal or fibroblastic cells, often with a typical histological, storiform pattern, qualify as MFH. Using these strict criteria, the diagnosis of MFH will become rarer, though not obsolete (like hemaugioperizytoma years ago!).

Histiocytoma, Benign Fibrous↗