PubMed Health⌕ Search

Biomedical subjects

G Youngberg

Publications and source records attributed to G Youngberg.

16 recordsLinked to original sources
PubMed2001

The human mast cell: functions in physiology and disease.

Mast cells are multifunctional, tissue-dwelling cells capable of secreting a wide variety of mediators. They develop from bone marrow-derived progenitor cells, primed with stem cell factor (SCF), which mediates its actions by interacting with the SCF receptor or c-kit on the cell surface. Mast cells continue their maturation and differentiation in peripheral tissue, developing into two well described subsets of cells, MCT and MCTC cells, varying in content of tryptase and chymase as well as in immunobiology. Mast cells are activated by numerous stimuli, including antigen (acting via the high affinity IgE receptor, Fc?RI), superoxides, complement proteins, neuropeptides and lipoproteins resulting in activation and degranulation. Following activation, these cells express mediators such as histamine, leukotrienes and prostanoids, as well as proteases, and many cytokines and chemokines, pivotal to the genesis of an inflammatory response. Recent data suggests that mast cells may play an active role in such diverse diseases as atherosclerosis, malignancy, asthma, pulmonary fibrosis and arthritis. Mast cells directly interact with bacteria and appear to play a vital role in host defense against pathogens. Drugs, such as glucocorticoids, cyclosporine and cromolyn have been demonstrated to have inhibitory effects on mast cell degranulation or mediator release.

Arteriosclerosis↗
PubMed2001

Acute and chronic urticaria. Challenges and considerations for primary care physicians.

Urticaria and angioedema are common dermatologic problems seen by primary care physicians. A carefully taken history, physical examination, specific tests, and skin biopsy often provide useful diagnostic information. In patients with chronic urticaria, urticarial vasculitis and diseases that mimic urticaria need to be ruled out. A variety of treatment options are available for patients with urticaria and urticarial vasculitis. Pharmacologic therapy is useful when the specific cause is undetermined. When a trigger has been identified, the patient must avoid exposure to it. Patient education is an important component of management and should include instructions on crisis management, particularly for patients who have angioedema or a tendency for anaphylaxis.

Acute Disease↗
PubMed1997

Delayed ulcer recurrence after gastric resection: a new postgastrectomy syndrome?

Recurrent ulceration following gastrectomy for peptic ulcer disease typically occurs within the first several years postoperatively. Since 1990, we have managed 20 patients who had undergone previous gastrectomy for peptic ulcer and developed ulcer recurrence more than 10 years postoperatively. Mean age at recurrence was 64 years, and the average time from original surgery to recurrent ulceration was 21 years (range, 10-36 years). All patients had undergone vagotomy and antrectomy (17 patients) or subtotal gastrectomy (3 patients). Presenting symptoms included gastric outlet obstruction (70%) and bezoar formation (60%). Endoscopic findings in this group of patients included a stenotic gastric outlet (70%) and marginal ulcerations (80%). Thirteen of 15 patients tested (87%) were Helicobacter pylori positive. Reoperation included partial resection of the gastric pouch and exploration for persistent vagus nerve. Twelve patients underwent Roux-en-Y reconstruction, whereas eight patients had Bilroth II reconstruction. Three of the latter group also had Braun enteroenterostomy performed. Good to excellent clinical results were obtained in 80 per cent of patients. The four patients with poor outcomes shared the following characteristics: 1) H. pylori-positive status, 2) presence of a preoperative bezoar, 3) Roux-en-Y reconstruction. Our current approach is to avoid Roux-en-Y construction in favor of Braun enteroenterostomy. Further prospective analysis of long-term postgastrectomy patients is needed to determine whether this clinical picture represents a new postgastrectomy syndrome.

Adult↗
PubMed1996

A new animal model of reversible acute pancreatitis.

Numerous animal models of acute pancreatitis are utilized to assess pathophysiologic events and to evaluate therapeutic options. However, none of the small animal models simulates reversible biliary pancreatitis with long-term follow-up (weeks). The present study was designed to create a reversible model of acute biliary pancreatitis in small experimental animals. Male Sprague-Dawley rats were subjected to laparotomy, and the common bile duct was dissected free at its junction to the duodenum. Experimental animals had a polypropylene tie occluder passed around the common bile duct and brought out through a separate stab wound in the abdominal wall. The duct was occluded for 24 hr; the blockage was then relieved and the tie withdrawn from the animal. Sham-operative animals had similar surgical procedures but without the occluder. Serum amylase values on Days 1 and 2 following surgery were significantly increased in the experimental group, but were not different from those of control animals on Day 3 or 4, suggesting reversibility of this biliary pancreatitis model. Likewise, serum bilirubin levels were increased in the experimental group on Days 1 and 2. Histologic analysis revealed edema, zymogen degranulation, inflammatory infiltration, vacuolization of acinar cells, and focal areas of fat and parenchymal necrosis in the experimental group. Only mild edema was observed in the sham-operative controls due to surgical manipulation. Pancreatic tissues obtained at 1 week postinduction of pancreatitis showed near total destruction of the architecture and dissolution of zymogen granules; in contrast, histology at the 3rd week showed almost normal-appearing pancreas with return of zymogen granules, suggesting recovery from the acute pancreatitis. This reproducible and reversible model of acute pancreatitis in the rat will provide for further studies in the pathogenesis of pancreatitis and its therapeutic interventions.

Acute Disease↗
PubMed1989

Melkersson-Rosenthal syndrome: elevations in serum angiotensin converting enzyme and results of treatment with methotrexate.

We have presented the case of a 37-year-old white man who had recurrent, unilateral, facial edema, temporary partial facial nerve palsy, sensory loss along the ophthalmic and maxillary divisions of the fifth cranial nerve, ageusia bilaterally on the anterior two thirds of the tongue, right extraocular muscle palsies, and intractable migraine-type headaches, leading to the diagnosis of Melkersson-Rosenthal syndrome. The serum angiotensin converting enzyme levels, which are postulated to derive from undiscovered granulomas, were found to be elevated. Methotrexate therapy mitigated the clinical course of the disease, and may prove to be useful in the treatment of this rare and recalcitrant condition.

Adult↗
PubMed1988

Atypical pigmented penile macules.

We describe three patients with pigmentary lesions of the penis that simulated malignant melanoma. The pathologic features were unimpressive, although one lesion may have represented a melanoma in evolution. The biologic potential of such lesions and their appropriate therapy remain to be defined.

Adult↗
PubMed1987

Electron microscopic studies of Moll's gland cyst.

Several Moll's gland cysts from 4 different patients were studied with the light and electron microscopes. The cysts were lined with a combination of several different epithelia, such as completely keratinized epithelium, glycogen-rich, stratified squamous epithelium with incompletely keratinized luminal cells, sweat duct epithelium, and secretory cells. In one case in addition to the above components, secretory-type wall cells contained very large lamellar inclusions which were PAS positive and diastase resistant. It was concluded that Moll's gland cyst is composed of dilated duct of the Moll's gland and secretory segment; the proportion of each segment is variable but the portion showing ductal differentiation is usually predominant and typical secretory epithelium is not always seen.

Aged↗
PubMed1979

Ultrastructural features of monomorphic adenoma of the parotid gland.

A monomorphic adenoma of the parotid gland (basaloid type) was studied with the electron microscope. In general, the tumor consisted of a single cell type, except in areas of squamous metaplasia. The cells were polygonal with prominent nuclei and scant cytoplasmic organelles. Intercellular junctions and plasmalemmal projections (filopodia) were conspicuous. Myoepithelial cells and secretory granules were absent. On the basis of these ultrastructural features, it is proposed that the interlobular duct, rather than the intercalated duct, is the probable site of origin of this tumor.

Adenoma↗