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Biomedical subjects

R David

Publications and source records attributed to R David.

At least 19 recordsLinked to original sources

Acute colitis associated with prolonged administration of neuroleptics.

We describe a 29-year-old patient who developed acute colitis limited to the sigmoid and left colon with features mimicking ischemic injury after a prolonged administration of trifluoroperazine and levomepromazine, two phenothiazines in association with haloperidol, another neuroleptic, and biperidene, an anticholinergic compound. The discontinuation of these drugs was followed by a prompt and complete recovery, and no other cause of acute colitis was found. The subsequent administration of sultopride, a neuroleptic from the benzamide family and then the readministration of haloperidol were well tolerated. No colonic disorder occurred for the following months. This case strongly supports the view that neuroleptic agents, in particular phenothiazines, may induce acute colitis and that haloperidol, a butyrophenone derivative, or sultopride, a benzamide-related neuroleptic, can be administered thereafter without recurrence of the disease.

Adult

Diurnal intraocular pressure variations: an analysis of 690 diurnal curves.

Out of a total of 2272 diurnal curves (DC) of intraocular pressure (IOP) obtained from 1178 patients 690 first curves of the right eye of all patients were analysed. For each DC there were 4-6 IOP readings taken between 8 am and 6.30 pm of the same day. The patients' diagnosis, age, sex, type of IOP lowering medication, diabetes, and the calendar month of the year were recorded. In 40% of cases the highest IOP was found at the earliest morning measurement with some 65% of peaks occurring before noon. The lowest IOP measurement showed no specific predilection for any particular time of the day. These findings were true for all diagnosis groups. The mean range of IOP fluctuation during the DC was 5.0 mm Hg in normals, 5.8 mm Hg in patients with open angle glaucoma (OAG), and 6.8 mm Hg in patients with ocular hypertension (OHT). Patients treated with timolol had a lower mean IOP fluctuation range than those on other types of IOP lowering treatment. No association was found between all other parameters examined and the diurnal IOP distribution.

Adrenergic beta-Antagonists

Radiotherapeutic agents: properties, dosimetry, and radiobiologic considerations.

Radioactive nuclides for treatment have occupied an important but somewhat diminishing role in the total practice of nuclear medicine. Although theoretically they should have important potentialities, particularly in the treatment of various forms of cancer, their development in this field has not kept pace with the progress in other treatment modalities in radiation oncology. Indications for the selection of appropriate isotopes for therapy revolve about the emission of beta particles of sufficient energy, which are administered in a chemical form that reaches the tumor. Methods of calculation of doses delivered to sites of deposition are discussed in the text. Radiobiologic considerations include the possibility of early deleterious effects from overdosage, and consideration of chromosomal changes of circulating lymphocytes and their implications. Late effects that have been of great public concern are confined almost solely to possible carcinogenesis, and this effect has been minimal in patients receiving therapeutic levels of radioactive drugs. Genetic and developmental effects, also, have been negligible. Complications encountered more frequently have been leukemia after extensive therapy of thyroid carcinoma, and local fibrosis after direct injection of radioactive colloids into tumor tissue.

Adolescent

Unilateral enlargement of the masseter muscle.

Benign hypertrophy of the masseter muscle is a relatively uncommon condition which may occur unilaterally or bilaterally. The etiology of the ailment is unclear in the majority of cases, and the histopathological features are usually those of normal muscle. A case of unilateral masseter muscle enlargement is described in a 19-year-old Arab male. The histopathological findings were compatible with a mild myopathic disorder. The characteristics, differential diagnosis, etiology, treatment and histopathological features of masserteric hypertrophy are discussed.

Adult

Lipofuscin in human tongue muscle.

In a study of 107 tongue specimens lipofuscin granules were found to be present in the muscle fibers of 93% of the cases. The pigment was not found in young individuals under the age of 18 years. The pigmented granules, which were stored in clusters of different sizes at the nuclear poles, were PAS-positive, stained black or brown with the Masson-Fontana procedure, black with Sudan black, and strong purple-pink with Ziehl-Neelson staining; yellow autofluorescene was emitted in ultraviolet light. The morphology, histochemical reactions and autofluorescence of the pigmented granules were characteristics of the endogenous lipid pigment described as lipofuscin. Statistical analyses indicated a direct correlation between increase in quantity and distribution of the pigment and increase in age (P = 0.001), in both males and females. Accumulation of the pigment in the tongue with aging was found to be similar to that in the myocardium.

Adolescent

HLA antigens in glaucoma and ocular hypertension.

Forty-five white patients (32 with open-angle glaucoma and 13 with ocular hypertension) and 63 black patients (41 with open-angle glaucoma and 22 with ocular hypertension) were tissue typed for a total of 38 HLA antigens and the results compared to normal, unrelated, panels of 248 white donors and 150 black volunteers, respectively. No statistically significant differences with regard to the frequencies of 38 HLA antigens were detected among the various groups.

Black People

Surgical treatment for pneumatosis cystoides intestinalis complicating jejunoileal by-pass.

A case of chronic pneumatosis cystoides intestinalis, complicating jejunoileal by-pass procedure for morbid obesity, is described. Grave clinical symptoms associated with irreversible segmental mucosal atrophy and mural fibrosis resulting from untreated long-standing pneumatosis intestinalis, required resection of the whole by-passed small intestine. It is suggested that this simple and safe surgical procedure is justified in selected cases. Conservative treatment of asymptomatic patients with pneumatosis intestinalis, however, may prevent further surgical intervention in these patients.

Adult

Increased glomerular filtration rate in patients with major burns and its effect on the pharmacokinetics of tobramycin.

The clearance of endogenous creatinine in 20 burned patients, measured between the fourth and the 35th post-burn day, was a mean (+/- S.D.) of 172.1 p 48.4 ml per minute per 1.73 m2; in eight normal subjects the mean value was 125.4 g- 10.4 (P less than 0.02). Thirteen patients had values more than 2 S.D. above the normal mean. We confirmed this rise in glomerular filtration rate by measuring inulin or iothalamate clearance in nine patients. The pharmacokinetics of tobramycin were studied in 11 of the 20 patients and in eight normal subjects receiving continuous intravenous infusions of the drug. An inverse correlation was found between plasma half-life of the drug and creatinine clearance (r = 0.68, P less than 0.01). Increased creatinine clearances and shortened half-life of tobramycin occurred mainly in younger patients. Glomerular filtration rates in burned patients may rise to very high values and can be validly measured by creatinine clearance. The plasma half-lives of drugs with predominantly urinary excretion may decrease in patients with burns.

Adult

Amyloid stroma in a tubular carcinoma of palatal salivary gland: a histochemical and ultrastructural study.

Amyloid as defined by positive Congo red green birefringence and STB red birefringence was observed in the stroma of a tubular carcinoma of minor salivary gland origin. The amyloid exhibited additional histochemical characteristics of immunamyloid, viz., positive DMAB-nitrate and DC-reactions and spontaneous autofluorescence. Electron microscopic studies of the epithelial tumor cells displayed large amounts of cytoplasmic microfilaments similar to those present in the extracellular amyloid masses. It is suggested that the amyloid is derived from spontaneous assembly or polymerization of cytoplasmic microfibrils of the dying tumor cells as has been proposed for the amyloid associated with the calcifying epithelial odontogenic tumor (CEOT).

Adenocarcinoma

Corpora amylacea in mesothelioma of the atrioventricular node.

Rounded or polyhedral, acellular, dense lamellated structures were seen within gland-like spaces in a case of atrioventricular mesothelioma. These structures exhibited many of the histochemical characteristics of amyloid, viz., pink colour with green birefringence and bright red fluorescence with alkaline Congo red; ortochromasia and red birefringence with standardised toluidine blue; positive DMAB-nitrite and diazotisation coupling reactions and spontaneous autofluorescence. It is suggested that these bodies are derived from spontaneous assembly or polymerisation of microfibrils of desquamated cells lining the cystic spaces of the tumour as occurs in prostatic corpora amylacea. The peculiar intramyofibre proliferation of tumour cells in the peripheral part of the tumour suggests that viable tumour cells can penetrate, survive and proliferate within atrial or nodal myofibres leaving an intact sarcolemmal sheath. The slow tumour cell growth and the successive degeneration of central tumour cells may explain the tubular and/or glandular pattern constantly seen in this tumour.

Aged

Lipofuscin in salivary glands in health and disease.

Lipofuscin granules were observed in normal salivary glands (parotid, submandibular, and minor salivary glands). The pigment was confined mainly to the epithelial cells of the intralobular ducts, but isolated granules were also found in acinar cells and myoepithelial cells. In chronic sialadenitis pigment granules were found in the intralobular epithelial cells and in macrophages in the surrounding ionnective tissue. In benign epithelial tumors pigment granules were observed within neoplastic epithelial cells and in macrophages in the stroma, while malignant tumors displayed pigmented granules only in macrophages in the stroma.

Adenoma, Pleomorphic

Corpora amylacea in adenolymphoma (Warthin's tumor).

Round or polyhedral, acellular, lamellated or amorphous eosinophilic structures were observed in the cystic spaces of adenolymphomas. These eosinophilic bodies ahd several of the histochemical characteristics of amyloid, viz., pink color with green specific birefringence and bright red fluorescence with alkaline Congo red; positive DMAB-nitrite and DC reactions, and spontaneous autofluorescence. It is suggested that these bodies are derived from spontaneous assembly or polymerization of microfibrils of desquamated epithelial cells lining the cystic spaces of the tumor, as has been described to occur in prostatic corpora amylacea.

Adenolymphoma

Lipopigment in odontogenic cysts.

A study of 105 odontogenic cysts revealed the presence of pigmented cells in the cyst wall in 38% of the cases. The frequency of pigmented cells was higher in the inflammatory odontogenic cysts than in the development cysts. Although isolated pigmented cells were seen within the epithelial lining and cyst cavity, the larger collections were closely associated with cholesterol crystals and hemosiderin deposits; they contained light brown cytoplasmic pigment which manifested sudanophilia, acid-fastness, silver reduction capacity, PAS positivity and yellow autofluorescence in ultraviolet light. The morphology, histochemical reactions and autofluorescence suggest that the pigmented cells are macrophages containing ceroids. It has been suggested that the hemosiderin which is found in the cyst wall serves as an oxidation catalyst for the locally liberated lipids, the end result of which is the formation of the ceroid pigment.

Cholesterol