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Biomedical subjects

I Chowers

Publications and source records attributed to I Chowers.

At least 37 records · Page 2Linked to original sources
PubMed1999

Immunostaining of the estrogen receptor in conjunctival primary acquired melanosis.

Conjunctival primary acquired melanosis (PAM) is a frequent precursor of conjunctival melanoma. Since there is indirect evidence that the conjunctiva is an estrogen-responsive tissue, and since it was suspected that estrogen has a role in the etiology of melanoma, we decided to evaluate whether PAM may be responsive to estrogen. Formalin-fixed, paraffin-embedded sections from 13 cases of PAM and 2 cases of conjunctival melanoma were immunostained with an estrogen-receptor (ER)-specific antibody. All lesions and the normal conjunctival tissue adjacent to the lesions were found to be ER negative. It is concluded that PAM and normal conjunctiva are not sensitive directly to estrogen. When considering previously reported data, it is conceivable that the normal conjunctiva, but not PAM, is indirectly affected by estrogen.

Adolescent↗
PubMed1999

Mitomycin-C in combined or two-stage procedure trabeculectomy followed by penetrating keratoplasty.

PURPOSE: To evaluate the efficacy and safety of application of mitomycin-C (MMC) in combined and separate trabeculectomy and penetrating keratoplasty for the treatment of coexisting corneal disease and glaucoma. METHODS: A retrospective evaluation of 11 eyes of 10 patients was conducted. A combined trabeculectomy with MMC and penetrating keratoplasty procedure was performed in eight eyes (group 1), and keratoplasty was performed after a previous trabeculectomy with MMC in three eyes (group 2). RESULTS: In group 1, seven of the eight eyes had controlled intraocular pressure (IOP) and clear corneal graft at the end of the follow-up period (range, 5-60 months; mean duration, 16.7 months). In group 2, all three eyes had controlled IOP at the end of the follow-up period (range, 4-30 months; mean duration, 14 months); two of these patients had clear corneal grafts, and graft failure occurred in the remaining patient. Complications included transient flat anterior chamber and corneal epithelial defects, each of which occurred in a single eye in group 1, and progressive cataract, which occurred in a single eye in group 2. CONCLUSION: Mitomycin-C was found to be safe and efficient in the present series, controlling IOP in 10 of 11 eyes (91%) with coexisting corneal disease and glaucoma. The transplanted corneas remained clear in 9 of 11 eyes (82%). Complications related to MMC included a reversible epithelial defect that occurred in one eye.

Adolescent↗
PubMed1998

Deep stromal inflammation--a possible new ocular manifestation of Crohn's disease.

Crohn's disease, an inflammatory bowel disease, is infrequently associated with epithelial and subepithelial corneal inflammation. However, deep stromal inflammation has not been described previously in association with Crohn's disease. We report on a 52-year-old male who suffered from anterior uveitis and deep stromal inflammation. Complete ocular and systemic workup revealed an active asymptomatic Crohn's colitis; no other possible cause for the ocular inflammation was found. We conclude that deep stromal inflammation, in addition to the previously reported corneal epithelial inflammation, may be associated with Crohn's disease.

Colitis↗
PubMed1998

MIB-1 and PC-10 immunostaining for the assessment of proliferative activity in primary acquired melanosis without and with atypia.

AIMS: To compare the proliferative activity of intraepithelial melanocytes in primary acquired melanosis (PAM) without atypia and PAM with atypia by immunohistochemical staining for the Ki-67 antigen and the proliferating cell nuclear antigen (PCNA). METHODS: Formalin fixed, paraffin embedded sections from 35 archival specimens of PAM without atypia (n = 19) and with atypia (n = 16) were studied by immunostaining with MIB-1 and PC-10 monoclonal antibodies that react with the Ki-67 antigen and PCNA respectively. The results were calculated as the mean number of positive cells per eyepiece grid. All specimens were evaluated by two masked observers, and the interobserver reproducibility was assessed. RESULTS: The means of the positive cell count in PAM with atypia were significantly higher compared with PAM without atypia for both observers, in both the PC-10 and the MIB-1 stained sections. In a linear least square model that estimated the interobserver and between group variation, the difference of MIB-1 and PC-10 positive cell count between PAM without and with atypia remained highly significant. The difference between the observers was not significant. CONCLUSIONS: Immunostaining with MIB-1 and PC-10 demonstrated that PAM with atypia has higher proliferative activity than PAM without atypia. This method was found to be reproducible between different observers.

Antigens, Nuclear↗
PubMed1996

Vinblastine toxicity to the ocular surface.

Local ocular exposure to antineoplastic drugs occurs either during regular use of some of these drugs in ophthalmology or accidentally during the general use of these drugs. Many ocular side effects have been described after such intentional or accidental exposures. We describe a case of accidental ocular trauma by vinblastine. As in one of the only two previously published cases of ocular trauma by vinblastine, our patient showed acute keratopathy with a drop in visual acuity followed by the development of dry eyes and a subepithelial corneal scar. In addition, in an attempt to further evaluate the clinical course and the benefits of steroid treatment, nine rabbits were studied after ocular instillation of vinblastine. After the trauma, local steroid treatment was given in one eye of each rabbit; the second eye served as a control. The animal studies showed acute conjunctivitis and keratopathy with increasing severity in the first days and improvement thereafter. That course was similar to the one manifested in our patient. Local steroid treatment in the rabbit eye had no effect as compared with the control group. A possible mechanism for the induction of dry eyes is discussed.

Accidents, Occupational↗
PubMed1986

[Dawn phenomenon].

Explore the source record for details and available documents.

Blood Glucose↗
PubMed1985

Effects of extrahypothalamic structures on the hypothalamic cell nuclear binding of corticosterone.

Hypothalamic or hippocampal slices were taken from adrenolectomized male rats either sham operated or with anterior (AHD) of posterior (PHD) hypothalamic deafferentations and from rats with dorsal hippocampectomy (DHIPP). The slices were incubated in Krebs-Ringer bicarbonate buffer in the presence of 10-60 nM 3H-corticosterone (CS) with or without 500 fold excess of unlabeled CS for 30 min. The cell nuclear binding in the hypothalami from either PHD of DHIPP rats were markedly reduced (by 50-70%) as compared to control or AHD rats. The binding of 3H-CS in hippocampi from AHD or PHD rats was not affected. These results suggest that extrahypothalamic structures can modulate the binding of CS in the hypothalamus by neural inputs entering the medio-basal hypothalamus from the caudal direction; such modulation may explain previously observed influences upon hypothalamic sensitivity to the feedback action of glucocorticoids by extrahypothalamic structures.

Animals↗
PubMed1985

Pneumatocele formation in a patient with Proteus mirabilis pneumonia.

A rare case of pulmonary pneumatoceles complicating the course of Proteus pneumonia in an adult is described. The pneumatoceles which appeared early in the course of the pneumonia resolved completely without complications. A brief review of the literature regarding formation of cavities in Proteus pneumonia is given.

Female↗
PubMed1984

A temporal study of post-adrenalectomy increase in ACTH secretion in the rat: effect of various hypothalamic deafferentations.

Adult male rats, intact (N) or with complete (CHD), anterior (AHD), or posterior (PHD) hypothalamic deafferentations were bilaterally adrenalectomized. At 3, 6, 12 and 20 days post-adrenalectomy they were decapitated and trunk blood was collected for ACTH determinations. In N rats, ACTH markedly elevated up to 850 pg/ml. A similar ACTH response was found in PHD rats but the values were lower by approximately 20%. In contrast, in either AHD or CHD rats, ACTH responses were markedly attenuated and reached a plateau of about 350 pg/ml. These data suggest that: (1) neural inputs entering the medio-basal hypothalamus (MBH) from both the caudal and rostral directions are important for obtaining maximal ACTH responses following adrenalectomy; (2) at least part of this ACTH response is mediated by sites inside the MBH or in the pituitary.

Adrenal Glands↗
PubMed1984

ACTH and corticosterone secretion following 2-deoxyglucose administration in intact and in hypothalamic deafferentated male rats.

Adult male rats were given a single i.p. injection of 2-deoxyglucose (2-DG, 100-400 mg/kg b. wt). The animals were decapitated 1-4 h later and trunk blood was collected for ACTH, corticosterone (CS) and glucose determinations. Serum ACTH and CS were markedly elevated when compared with saline-treated animals; these elevations were correlated with given doses of 2-DG so that with the higher dose, an approximately 6-fold increase in serum levels of both hormones was observed. Injection of 2-DG up to 200 mg/kg did not change serum glucose levels; injection of 400 mg/kg of 2-DG increased serum glucose by approximately 2-fold. A time course study showed that levels of serum ACTH, CS and glucose were maximal 1 h after 2-DG administration and returned to basal values 3 h later. Injection of 2-DG to animals with complete hypothalamic deafferentation failed to induce any change in serum ACTH, CS or glucose. This study demonstrates that: (1) 2-DG can stimulate the hypothalamo-hypophyseal-adrenal (HHA) axis as measured by ACTH and CS; this effect is not related to blood glucose levels; (2) the HHA response to 2-DG is mediated by sites outside the mediobasal hypothalamus.

Adrenal Cortex↗
PubMed1984

Deafferentation reduces the hypothalamic cell nuclear binding of corticosterone.

Hypothalamic or hippocampal slices and adenohypophyseal lobes taken from adrenalectomized male rats either intact or with complete hypothalamic deafferentation (CHD) were incubated in Krebs-Ringer bicarbonate buffer in the presence of either 10-50 nM [3H]corticosterone or [3H]dexamethasone with or without 500-fold excess of unlabeled steroid for 15-60 min. The cell nuclear binding in the hypothalamic slices from the CHD rats, was markedly reduced by approximately 50% but remained unchanged in the hippocampi and in the pituitaries. These results suggest that brain sites outside the mediobasal hypothalamus are important for the regulation of corticosterone binding in the hypothalamus.

Adrenalectomy↗
PubMed1984

Dysphagia as a primary manifestation of hyperthyroidism.

A 69-year old woman suffered from severe dysphagia, abdominal pain, and weight loss. The dysphagia was accompanied by nasal speech, nasal regurgitation of food, weakness, and wasting of the proximal muscles of the upper and lower girdles. Laboratory data revealed T3 sephadex uptake 65.2%; T4 15.1 mcg%; and T3 250 ng%. Treatment with antithyroid medication reversed the manifestation of all the symptoms, including dysphagia. Cine-studies revealed esophageal motor dysfunction as the cause of the dysphagia. Hyperthyroidism is a rare, but treatable cause of unexplained dysphagia.

Aged↗