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Biomedical subjects

L D Rowe

Publications and source records attributed to L D Rowe.

At least 55 records · Page 3Linked to original sources
PubMed1982

Tonsils and adenoids. When is surgery indicated?

The efficacy of tonsillectomy and/or adenoidectomy in the management of urgent problems such as cor pulmonale, acute airway obstruction, or functional impairment of nasal respiration, speech, or swallowing is unquestioned. However, relative indications for surgery such as odynophagia, otalgia, or otitis media with effusion are more controversial. The limitations and risks of tonsillectomy and adenoidectomy in these patients are explored.

Adenoidectomy↗
PubMed1982

Cytoplasmic bridges between mammalian red blood cells: an early indication of kidney dysfunction.

Scanning electron microscopy, correlated with hematological and clinical biochemical observations demonstrated that cytoplasmic bridges develop between the erythrocytes of sheep in which varying degrees of acute renal dysfunction has been produced by treatment with a toxin (uranyl nitrate) or by surgical ligation of a renal artery or ureter. The presence of cytoplasmic bridges between red blood cells was noted prior to clinical indication of renal dysfunction. Thus, these preliminary studies indicate that the development of cytoplasmic bridges between erythrocytes may be a diagnostic clue for early detection of renal dysfunction.

Animals↗
PubMed1982

Acute toxicity of tri-ortho-cresyl phosphate in sheep and swine.

Tri-ortho-cresyl phosphate (TOCP) was given orally or by subcutaneous (SC) injection to sheep and swine. Sheep given oral doses of 100, 200, or 400 mg of TOCP/kg of body weight developed an acute intoxication characterized by diarrhea dehydration, metabolic acidosis, and death within 6 days. Daily SC injections of TOCP in sheep caused either death or delayed neurotoxicosis depending upon the dosage. Increase of aspartate aminotransferase activity approximately 24 hours before the animal died and histopathologic changes confirmed that liver injury had occurred. Swine dosed with 100 to 1,600 mg of TOCP/kg had minimal signs of acute toxicosis, but developed severe delayed neurotoxicosis in approximately 15 days. Those given a 800 mg/kg dose by the oral route or SC injection had severely decreased serum acetylcholinesterase activity. In the swine which were euthanatized at 7 days after treatment, histopathologic examinations revealed no lesions (although the nervous system was not examined, because clinical neurologic signs were normal).

Administration, Oral↗
PubMed1981

Computed tomography in maxillofacial trauma.

Computed tomography (CT) has become the key diagnostic modality in the evaluation of head trauma. Experience with CT in the operative assessment of maxillofacial injuries is limited, however. Plain films and multidirectional tomography have been used until now to define fractures in the facial region. We examined 27 patients sustaining maxillofacial trauma with CT scans. Ten patients were studied in the coronal plane, 12 in the axial plane, and the remaining 5 in both the axial and coronal planes. Polycycloidal tomography in the coronal and/or sagittal plane was obtained in 18 patients for comparison with the CT scan. Fracture lines, bony fragments, and associated skeletal deformities were clearly identified by CT scan in all 27 patients permitting the diagnosis of zygomatic, orbital floor, nasoethmoidal complex, LeFort, temporal bone, frontal sinus, and mandible fractures. More importantly, concomitant intracranial injuries including epidural and intracerebral hematomas, traumatic encephalocoele, and pneumocephalus were readily seen. In addition, facial and orbital soft tissue structures including the globe, optic nerve, orbital fat, and extraocular muscles were easily examined by adjusting the CT level and window settings. Overall, CT yielded additional information not available from polytomography in 15 of 18 cases when both modalities were used. Multidirectional tomography is currently superior to CT scanning if fine, intrinsic bone detail is required. However, we have found that complex fractures with fragmentation are more easily identified on CT scans than conventional tomography because of superior contrast resolution of computed tomography. With improved spatial resolution, CT scanning may totally supplant multidirectional tomography in the evaluation of maxillofacial trauma.

Adult↗
PubMed1981

Ophthalmic surgery in malignant exophthalmos.

Malignant exophthalmos or the ophthalmic component of Graves' disease is a functionally impairing and cosmetically deforming disorder of orbital tissue, separate from the sympathetic effects of thyrotoxicosis. The deposition of immune complexes of thyroglobulin and its antibodies within orbital muscles results in progressive exophthalmos, ophthalmoplegia, chemosis, and lid fullness. Increasing intraorbital edema and optic nerve tension may produce irreversible retinal ischemia. If unresponsive to medical treatment, patients exhibiting increasing loss of visual acuity are therefore candidates for emergency surgery. Early attempts at surgical correction of the mechanical aspect of Graves' ophthalmopathy were unsuccessful. The current technique of transantral orbital decompression, when done before extreme advancement of the ocular disease, is successful and meets the following objectives: It restores visual loss and prevents further deterioration of visual acuity, protects the cornea, restores extraocular muscle movements, decreases intraorbital pressure, produces a satisfactory cosmetic result, and avoids serious complications. Patients with persistent extraocular muscle imbalance or lid lag may ultimately require oculoplastic surgery.

Diagnosis, Differential↗
PubMed1981

Ultrastructural observations in ponies after treatment with monensin.

Ultrastructural studies were made of myocardium, diaphragm, appendicular muscle, liver, and kidney of 3 ponies acutely poisoned with a single oral dose of monensin (4 mg/kg of body weight). These ponies developed severe signs of toxicosis and were killed 28 to 72 hours after treatment. Severe mitochondrial damage (swelling) and lipoidosis in myocardial tissues were observed in 2 of the 3 ponies; similar, but less severe, changes were observed in the 3rd pony. The hepatocytes of the 3 ponies were characterized by increased amounts of smooth endoplasmic reticulum, large numbers of lipid droplets, vacuoles bounded by fibrous material, and a 2-fold increase in the number of peroxisomes per cell. Some hepatocytes also contained a membrane-bounded protein-like body. The observations indicate that heart mitochondria are primary targets of monensin poisoning in ponies.

Animals↗
PubMed1980

Advances and controversies in the management of supraglottitis and laryngotracheobronchitis.

Recent advances in pediatric airway intubation and the introduction of pharmacotherapeutic agents, active within the larynx and tracheobronchial tree, have created significant controversies in the treatment of acute obstructive inflammatory laryngeal disease. Although the etiology, pathophysiology, and clinical patterns of supraglottitis and laryngotracheobronchitis are no longer confused, decisions concerning their medical management and method of airway control remain controversial. Both inflammatory disorders are critically examined, with a reveiw of current concepts regarding the choice between endotracheal intubation and tracheotomy. Specific problems of anesthetic technique, criteria for extubation or decannulation, and the rationale for the use of corticosteroids, antibiotics, or racemic epinephrine are evaluated. If mechanical airway control is required, careful attention to initial intubation with a relatively small, cuffless polyvinyl chloride endotracheal tube and precise surgical technique when employing tracheotomy will minimize the overall morbidity. Short term intubation in acute obstructive inflammation of the larynx appears to be well tolerated. Tracheotomy is reserved for the few patients with laryngotracheobronchitis who demonstrate persistent significant subglottic edema.

Acute Disease↗
PubMed1980

Adenocarcinoma of the ethmoid following radiotherapy for bilateral retinoblastoma.

Adenocarcinoma of the ethmoid sinus is rare, representing only 4-8% of malignancies of the paranasal sinuses. An extraordinary case of papillary adenocarcinoma of the ethmoid sinus arising 30 years following high-dose radiotherapy for bilateral retinoblastoma is presented. Retinoblastoma, though occurring only once in every 23,000 to 34,000 births, is the most common malignant intraocular tumor of childhood. Second fatal mesenchymal and epithelial primaries have been described in 8.5% of patients with bilateral retinoblastomas previously treated with radiotherapy; however, papillary adenocarcinoma arising within the paranasal sinuses has not been reported. Histologically, the findings of a papillary pattern of poorly differentiated, mucicarmine-staining cells enclosing gland-like spaces, and the absence of pseudorosettes, melanin, mesenchymal and peripheral neural elements supports an epithelial origin of this tumor. Agressive treatment including partial maxillectomy, radical pansinusectomy, radical neck dissection followed by regional radiotherapy and systemic chemotherapy failed to prevent the development of fatal hepatic metastases. The high incidence of second fatal primary neoplasms in patients with bilateral retinoblastomas receiving radiation suggests an innate susceptibility that may add to the risk of radiotherapy. Careful long-term head and neck surveillance is mandatory if early aggressive management of these extremely lethal tumors is to be successful.

Adenocarcinoma, Papillary↗
PubMed1980

Continuous measurements of skin surface oxygen and carbon dioxide tensions in obstructive sleep apnea.

We have found that skin surface electrodes for continuously measuring oxygen (PSO2) and carbon dioxide (PSCO2) tensions provide reliable means of determining whether infants with apnea due to airway obstruction during sleep require treatment. Nine patients referred for evaluation of aqnea during sleep were studied. In 6 patients with PSO2 less than 50 torr during sleep, the hypoxic episodes were clearly associated with partial or total airway occlusion as judged by increasing respiratory effort without concomitant airflow. PSCO2 was found to increase during the episodes of obstruction in all 6 patients. These patients were treated with 1. tracheotomy, 2. tonsillectomy and adenoidectomy in 2 patients, 3. bilateral mandibular condylotomies, 4. pharyngeal flap release, and 5. discontinuing topical nasal decongestants. After treatment, all had decreased hypoxia, hypercarbia, or airway obstruction. Two of the remaining 3 patients had no alterations of PSO2 or PSCO2 associated with airway obstruction during sleep. The third exhibited hypoxia and hypercarbia secondary to central apnea. We conclude, therefore, that continuous monitoring of skin surface oxygen and carbon dioxide tensions is useful in evaluating children with obstructive sleep apnea.

Airway Obstruction↗
PubMed1980

Effect of age on tolerance of calves to chlorpyrifos.

Groups of five calves (1 to 2 weeks old) or older calves (4 to 6 months old) were treated topically with increasing concentrations of chlorpyrifos [O,O-diethyl-O(-3,5,6-trichloro-2-pyridinyl) phosphorothioate] to determine their susceptibility to chlorpyrifos toxicity. Newborn calves also were given oral doses of technical grade (97.4%) chlorpyrifos to estimate their susceptibility by this treatment route. Topical applications to newborn calves consisted of 0.02%, 0.06%, or 0.12% chlorpyrifos administered as a spray to the entire body surface. Oral dosages given the newborn calves consisted of 5, 10, or 25 mg of chlorpyrifos/kg of body weight. Topical applications were administered to the older calves in the same manner as were applications to the newborn calves, but at concentrations of 0.25%, 0.5%, 0.9%, or 2.3%. Minimum dosages producing signs of toxicosis in newborn calves which were orally and topically given chlorpyrifos were 25 mg/kg of body weight and 0.06%, respectively. All five newborn calves sprayed with 0.12% chlorpyrifos were severely poisoned and were treated with atropine. One of these calves died within 48 hours after exposure to chlorpyrifos despite antidotal therapy. Signs of poisoning were not observed in older calves sprayed with 0.25%, 0.5%, or 0.9% chlorpyrifos. One Brahman-cross calf sprayed with 2.3% chlorpyrifos developed signs of mild poisoning that dissipated in 72 hours without treatment. Four older non-Brahman calves sprayed with 2.3% chlorpyrifos did not show signs of poisoning. Seemingly, 4- to 6-month old calves have an increased tolerance to topically applied chlorpyrifos compared with the tolerance of newborn calves, and the magnitude of this increased tolerance is 30-fold or higher.

Administration, Oral↗
PubMed1980

The antagonistic effect of L-cysteine in experimental hymenoxon intoxication in sheep.

L-Cysteine was given IV at dosages of 34.5, 48.8, 69.0, 97.6, or 138.0 mg/kg of body weight to groups of sheep previously treated (10.6 minutes) intraperitoneally with an LD92 of hymenoxon (12.8 mg/kg). L-Cysteine at dosages of 69.0, 97.6, and 138.0 mg/kg significantly increased survival rate 8.4-, 10-, and 12.5-fold, respectively, over that of gymenoxon-treated sheep not given L-cysteine. L-Cysteine at dosages of 34.5 and 48.8 mg/kg failed to significantly reduce mortality. Surviving hymenoxon-treated sheep given 97.6 or 138.0 mg of L-cysteine/kg showed mild or no clinical signs of toxicosis. There was no dosage of L-cysteine that significantly changed the survival time for fatally intoxicated sheep.

Animals↗
PubMed1979

Meningitis and hearing loss in children.

The hospital records for 100 cases of meningitis in which acute audiometric data has been obtained were reviewed. The incidence of sensorineural hearing loss was found to be 6%. The severity of hearing impairment varied from mild to profound and was frequently bilateral and irreversible. Two-cases showed asymmetrical involvement, and in one case, there was subsequent improvement in threshold sensitivity. Factors that influenced the incidence of neurologic sequela included severity of the initial disease process, age of the patient, and duration of symptoms before diagnosis and treatment. We discuss the pathophysiologic mechanisms that may account for such hearing loss, and we emphasize the importance of early diagnosis and intensive antimicrobial therapy. Careful neurologic evaluation is required after recovery and must include periodic sequential audiometric testing.

Age Factors↗
PubMed1979

Transbronchial drainage of pulmonary abscesses with the flexible fiberoptic bronchoscope.

Flexible fiberoptic bronchoscopy with multiplanar fluoroscopic control is shown to be effective in the transbronchial drainage of pulmonary abscesses. A new technique which permits the intracavitary placement of brush forceps and fine arterial catheters is described. This has facilitated the rapid defervescence of fever and established immediate endobronchial drainage. Seventy percent of patients had complete radiographic closure of their abscess cavities at three months. Clinical findings are presented and the role of aspiration in pathogenesis of pulmonary abscess is stressed.

Adult↗
PubMed1979

Bronchial adenoma: a malignant misnomer.

Bronchial adenomas are a histologically and clinically diverse group of respiratory tract neoplasms arising from mucous glands and ducts of the tracheobronchial tree. They represent 1% of pulmonary malignancies. The traditional concept of a single, histologically benign form is challenged and the malignant potential of these tumors is stressed. Three main cell types with their characteristic histopathologic and clinical features are discussed: carcinoid, adenoid cystic carcinoma, and mucoepidermoid carcinoma. A case of bronchial carcinoid with hepatic metastases is reported, emphasizing the malignant potential of this controversial group of tumors. The appropriate diagnostic evaluation is outlined and aggressive surgical management is stressed. Chemotherapy and radiation therapy which are reserved mainly for palliation do not add to overall five year survival rates.

Adenocarcinoma↗