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Biomedical subjects

H J Richter

Publications and source records attributed to H J Richter.

At least 19 recordsLinked to original sources
PubMed1992

Mucoid cytoplasmic inclusions in urothelial carcinomas.

To date, mucoid cytoplasmic inclusions in urothelial carcinomas have rarely been noted. However, we were impressed by the fact that these corpuscles are readily detectable in numerous urothelial neoplasms. Therefore, a histologic analysis of 100 cases of urothelial carcinomas was performed. Overall, 37 cases revealed periodic acid-Schiff-positive cytoplasmic inclusions. These were observed in 14% of grade 1, 49% of grade 2, and 63% of grade 3 carcinomas. The inclusions were histochemically, immunohistochemically, and ultrastructurally identified as cytoplasmic deposits of mucoid materials. Two types of deposits, condensed and noncondensed, could be distinguished. The demonstration of mucoid deposits in otherwise poorly differentiated metastatic carcinomas may be of some differential diagnostic importance insofar as urothelial carcinoma has to be considered as the possible primary tumor.

Carcinoma, Transitional Cell↗
PubMed1991

Air cooling for an interstitial microwave hyperthermia antenna: theory and experiment.

Microwave antennas are inserted through brachytherapy catheters implanted in a tumor to deliver interstitial hyperthermia cancer therapy. Theoretical calculations show that a cooling rate on the order of 0.1 W/cm length of catheter will significantly improve the radial uniformity of the temperature distribution of single antennas or arrays. Experiments and theoretical calculations show that air passing through the annulus between the antenna and the catheter at 10 L/min or less will produce such a cooling rate in a 2.2-mm OD catheter that has both ends accessible. To maintain uniformity of cooling rate along the catheter, it is better to control the cooling rate by preheating the air entering the catheter to 30-40 degrees C than it is to control the flow rate of room-temperature air. Ohmic heating of the antenna feedline does not confound the air cooling action significantly.

Electric Conductivity↗
PubMed1990

Electrodissection tonsillectomy.

A prospective, double-blind study was undertaken to compare the technique of removing tonsils using cold dissection with selective cauterization vs electrocautery dissection. The length of the procedure, blood loss, degree of pharyngeal pain, otalgia, and incidence of postoperative hemorrhage was recorded for 106 consecutive patients. In addition, our experience in performing the electrodissection tonsillectomy in 2431 patients is reviewed. Electrodissection tonsillectomy is a safe and effective procedure that offers several advantages over that of cold dissection using selective cautery.

Double-Blind Method↗
PubMed1989

[Spontaneous remission in disseminated histiocytosis X].

An 8 months old girl presented with biopsy-proven, disseminated histiocytosis X affecting at least two organ systems. Within one year there was spontaneous regression of the disease lasting for 10 years until today. Considering this case and others from literature the necessity of aggressive chemotherapy in selected cases is discussed.

Biopsy↗
PubMed1988

Unusual cause of recurrent arterial embolism: floating thrombus in the aortic arch surgically removed under hypothermic cardiocirculatory arrest.

A 46-year-old fully active, asymptomatic man suffered two episodes of major peripheral arterial embolism within 2 months. Heart disease was ruled out by appropriate investigations. Further diagnostic evaluation (angiography, CAT scan) revealed the extremely rare finding of a "floating mass" in the transverse aortic arch suspected to be the source of embolization. This mass was successfully removed using the technique of hypothermic cardiocirculatory arrest. The histological diagnosis was an aged intraluminal thrombus and moderate atherosclerosis of the thoracic aorta. For prevention of recurrent arterial embolism in cases without an initially apparent cause and site of origin, a thorough diagnostic, and in a given patient, an aggressive surgical approach for the elimination of the embolic source are advocated.

Aorta, Thoracic↗
PubMed1988

[Granular cell tumor of the orbit].

The authors report on the rare case of the intraorbital localisation of a granular cell tumour. Nature, histogenesis and biological behaviour of this lesion are discussed. The therapeutical consequences are presented.

Adult↗
PubMed1987

[Atypical congenital dyserythropoietic anemia].

The case is presented of a 26-year-old male patient suffering from chronic anemia since infancy. At age 12 (1972), congenital dyserythropoietic anemia (CDA) was diagnosed which could not be grouped with one of the three known variants of CDA. From onset the disease was complicated by thrombocytopenia with severe hemorrhagic diathesis. After splenectomy (1972) an extremely enlarged accessory spleen was removed in 1985 disclosing, histologically, excessively developed extramedullary hematopoiesis. Since bone marrow biopsy showed massive hyperplasia, the cellular phase of a myeloproliferative syndrome could not be excluded by histology alone.--Only a few cases of CDA with involvement of granulocytes and megakaryocytes have been reported so far. It is not clear whether or not they should be classed with CDA. In any event, involvement of granulopoiesis and/or thrombopoiesis indicates a genetic lesion of very early precursors, perhaps stem cells. It is proposed that such variants would be more correctly designated "congenital dyshematopoietic syndromes".

Adult↗
PubMed1987

[Non-ocular, malignant secondary tumor following spontaneous healing of a retinoblastoma ("retinoma", "retinocytoma")].

In a 47-year-old patient, the father of a child with bilateral retinoblastoma, three retinomas or retinocytomas were observed in the right eye, which had never been treated, in the course of a routine checkup. The left eye had been enucleated at age three-and-a-half because of a tumor of unknown etiology. At age 55 the patient died of lung cancer. The autopsy revealed a metastasized small-cell bronchial carcinoma. Histopathological examination of the right eye showed, in the region where the tumors had been observed clinically, merely disorganized retinal tissue with proliferations of pigment epithelium in some areas, and well-differentiated retinoblastomas in others. Tumor regression and differentiation appear to be the mechanisms responsible for spontaneous healing of the retinoblastoma. This case also emphasizes the threat posed by non-ocular secondary tumors to carriers of retinoblastoma genes.

Calcinosis↗
PubMed1987

[Bronchial cancers with morphologic and immunohistochemically diversely differentiated metastases].

We report on two unusual adenocarcinomas of the lung. The primary of the first case could be classified as a "solid adenocarcinoma" of the lung, whereas the metastases were undifferentiated and contained syncytiotrophoblast-like tumor cells. The primary of the second case consisted of diversely differentiated cells including adenocarcinomatous and syncytiotrophoblast-like cells, while the metastases were either adenocarcinomatous or syncytiotrophoblastic-like differentiated. Immunohistochemically, both primaries showed abundant CEA and little beta-HCG, while the metastases exhibited little CEA and abundant beta-HCG. The implications of such differences between the primaries and their metastases for tumor-cell heterogeneity and tumor classification are discussed.

Adenocarcinoma↗
PubMed1986

[Toxoplasmosis after bone marrow transplantation].

An opportunistic infection with Toxoplasma gondii is a rare complication in the immunocompromised host following bone marrow transplantation. In addition to the variability in the clinical picture, difficulty in interpretation of the antibody titers is one of the main obstacles limiting early diagnosis of manifest toxoplasmosis. This report deals with 3 patients out of 86 bone marrow transplant recipients who had manifest toxoplasmosis mainly affecting the central nervous system and cardiac muscle. The clinical picture was that of acute disseminated encephalitis and myocarditis, while the nature of the disease was only disclosed at autopsy.

Adult↗
PubMed1985

Mucin in carcinomas of the thyroid.

One hundred forty-two cases of thyroid carcinomas were studied to assess the frequency with which mucinous deposits occur within the neoplastic cells. In contrast to the literature, which contains only a few scattered reports on this topic, the production of mucin by carcinomas of the thyroid was relatively frequently observed in our material. Almost one half of the cases displayed mucinous substances, which occurred in about 50% of the papillary and the medullary carcinomas, 35% of the follicular types, and about 21% of the anaplastic varieties. The amount of mucinous substances varied considerably: 28 cases were weakly positive, 30 cases were moderately positive, and 6 cases were strongly positive. These findings are discussed with respect to diagnostic and differential diagnostic problems, especially with respect to the interpretation of mucinous deposits that occur in metastatic carcinomata.

Adenocarcinoma↗