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Biomedical subjects

D Van Wormer

Publications and source records attributed to D Van Wormer.

5 recordsLinked to original sources
PubMed1991

Tissue peroxidase in the normal and neoplastic salivary gland.

Peroxidase activity was measured by two colorimetric methods in six neoplastic tumors of the parotid salivary gland. When p-phenylenediamine was used as the hydrogen donor co-substrate, peroxidase activity was absent or reduced from 6 to 22% of normal in these tumors. Cross reactivity with normal peroxidase antibody could not be demonstrated in tumors exhibiting negative activity. Two neoplastic salivary glands had well-described, encapsulated tumors which showed reduced peroxidase activity when compared with the normal uninvolved portion. However, when guaiacol was substituted for p-phenylenediamine, normal activity was recorded. After dialysis, peroxidase activity was not enhanced. Mixing experiments showed no effect of the tumor extract on the peroxidase activity of normal saliva, nor on salivary gland supernatant. Normal salivary gland peroxidase was inhibited 90% by 10(-2) g/L amino-triazole, but neoplastic tumors were inhibited less (13 and 73%). It is suggested that peroxidase is a simple marker for the detection of neoplasia and can be of value in the differentiation of benign tumors.

Adenoma↗
PubMed1980

Malignant carcinoid syndrome: two case reports.

The malignant carcinoid syndrome (MCS) is a rare complication of malignant carcinoid neoplasms, fewer than 200 cases having been reported since its description by Thorson in 1954. Its signs and symptoms vary with the site of the primary neoplasm, and MCS is now recognized as one member of the large family of endocrine tumors--APUDOMAS). Although MCS remains uniformly fatal, significant palliation can be provided some patients with current surgical and chemotherapeutic management. All signs and symptoms in MCS, except evidence of the destruction of the tricuspid and pulmonic valves, can be reproduced experimentally. The factor causing this lethal complication has not been identified. Two previously unreported cases of MCS, each from the gastrointestinal (GI) tract, are presented. This brings the world's total report cases to approximately 210.

Aged↗
PubMed1977

A surgical technique for resecting malignancies invading the facial nerve and petrous pyramid.

Certain head and neck malignancies tend to invade branches of the cranial nerves and progress centripetally. The maxillary and mandibular divisions of the V (trigeminal) nerve are the most commonly invaded, but the VII (facial) nerve may harbor extensions of primary parotid malignancies and/or skin cancers originating in or near the ear. Paresis of the VII nerve signifies a serious but not entirely hopeless situation if countered with an appropriate surgical procedure. The optimal treatment of malignancies invading cranial nerves is surgical excision, which may necessitate removal of substantial portions of the cranium. Surgical pursuit of a malignancy in the facial nerve leads to a direct confrontation with the petrous pyramid of the temporal bone. Resection of the petrous pyramide is surgically feasible, but, if performed en bloc, extracts a high morbidity and mortality. An alternate technique in which the soft tissue and bones are removed disjunct is advocated. In this technique, the soft tissues are excised flush with the surface of the temporal bone. After making perforator and burr openings in the squamous temporal bone, a subtotal temporal craniectomy is completed with rongeurs. A prerequisite for success with this technique is the rotation of a large scalp flap and other local flaps to cover the exposed meninges and carotid arteries. A resume of four cases using this technique is presented. The age of the patients, the type, stage, and duration of the malignancies, and other factors which might influence the end stage results are given.

Aged↗
PubMed1977

Decreased amniotic fluid peroxidase in malignancy of the cervix.

Studies of amniotic fluid obtained at various times throughout the last trimester of pregnancy from patients with carcinoma of the cervix indicate a complete deficiency of peroxidase activity. Dialysis partially restores the enzyme activity. Cervical epithelial tumor cells apparently release a dialyzable, low molecular weight inhibitory substance directed specifically toward peroxidase. If this proves to be true in future studies, the peroxidase assay could be a sensitive means of differentiating between carcinoma and dysplasia. A peroxidelike substance was also present in the amniotic fluids obtained from patients with carcinoma. Other investigators have demonstrated large amounts of peroxide in malignant tumors. These elevated peroxide levels might well be directly related to deficient peroxidase activity rather than being a result of other abnormal enzyme levels which have been regarded as being principally involved in the metabolism of this highly toxic molecule.

Amniotic Fluid↗