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Biomedical subjects

A Lambiase

Publications and source records attributed to A Lambiase.

At least 55 records · Page 3Linked to original sources

Estrogen and progesterone receptors in vernal keratoconjunctivitis.

PURPOSE: Sex-related influences have been implicated in the pathogenesis of vernal keratoconjunctivitis (VKC), an allergic eosinophilic disease. METHODS: The authors evaluated tarsal and bulbar conjunctival biopsies from seven patients with severe and symptomatic VKC for the presence of estrogen and progesterone receptors by using monoclonal antibodies with a peroxidase-antiperoxidase technique. RESULTS: Both the epithelium and subepithelium of the tarsal and bulbar conjunctiva of patients with VKC, but not those of four nonatopic control subjects, showed intense positive staining for estrogen and progesterone receptors. Immunofluorescence colocalization of both estrogen and progesterone receptors with eosinophil cationic protein showed that approximately 70% of positive cells were eosinophils. CONCLUSIONS: Sexual hormones, through their receptors, may influence the activity of eosinophils in patients with VKC.

Adolescent↗

Increased plasma levels of nerve growth factor in vernal keratoconjunctivitis and relationship to conjunctival mast cells.

PURPOSE: To evaluate the nerve growth factor (NGF) plasma concentration in patients with vernal keratoconjunctivitis and to correlate it with the histopathology and immunopathology of the disease. METHODS: An immunoenzymatic assay was performed to measure NGF plasma levels in patients with vernal keratoconjunctivitis and in healthy matched controls. A competitive radioimmunoassay was used to detect eosinophil cationic protein (ECP) and total specific immunoglobulin E (IgE) serum levels. Histologic evaluation was performed in tarsal and bulbar conjunctival biopsies. RESULTS: Plasma levels of NGF were significantly higher (P < 0.001) in patients with vernal keratoconjunctivitis (mean = 8224.47 +/- 7802.53 pg/ml; median = 121 pg/ml) than in controls (mean = 51.68 +/- 5.94 pg/ml; median 42.5 pg/ml). Conjunctival tissue showed a significant increase of mast cells, eosinophils, and lymphocytes in vernal keratoconjunctivitis. A significant correlation was observed between plasma levels of NGF and the number of mast cells in the tarsal conjunctiva (Cc = 0.81; P < 0.005) and bulbar conjunctiva (Cc = 0.77; P < 0.01) of patients with vernal keratoconjunctivitis. No correlation was found between NGF plasma levels and total IgE serum levels in patients with vernal keratoconjunctivitis; NGF plasma levels were inversely related to the number of circulating eosinophils (Cc = -0.61; P < 0.05) and to the increased serum levels of ECP (Cc = -0.71; P < 0.02). CONCLUSIONS: These data represent the first reported evidence of increased NGF plasma levels in an allergic human disease and suggest a possible relationship between this neurotrophic polypeptide and inflammatory cells in vernal keratoconjunctivitis.

Adolescent↗

Emotional stress induced by parachute jumping enhances blood nerve growth factor levels and the distribution of nerve growth factor receptors in lymphocytes.

We examined the plasma nerve growth factor (NGF) level and the distribution of NGF receptors in peripheral lymphocytes of young soldiers (mean age, 20-24 yr) experiencing the thrill of a novice about to make their first parachute jumps. Blood was collected from soldiers who knew they were selected to jump (n = 26), as well as from soldiers who knew they were not selected (n = 17, controls). The former group was sampled the evening before the jump and 20 min after landing. Compared with controls, NGF levels increased 84% in prejump and 107% in postjump sampling. Our studies also showed that the increase of NGF levels preceded the increase of plasma cortisol and adrenocorticotropic hormone. No changes in the baseline levels of circulating interleukin 1 beta or tumor necrosis factor were found, suggesting that the increased levels of NGF were not correlated with change in these cytokines. Moreover, immunofluorescence analysis demonstrated that parachuting stress enhances the distribution of low-affinity p75LNGFR and high-affinity p140trkA NGF receptors in circulating peripheral blood mononuclear cells. These observations suggest that the release of NGF might be involved in the activation of cells of the immune system and is most probably associated with homeostatic adaptive mechanisms, as previously shown for stressed rodents.

Adult↗

Increased serum levels of eosinophil cationic protein and eosinophil-derived neurotoxin (protein X) in vernal keratoconjunctivitis.

PURPOSE: To evaluate whether the eosinophil preformed mediators, eosinophil cationic protein X, and eosinophil-derived neurotoxin/eosinophil protein X (EDN/EPX) are detectable in serum and can be used as markers of eosinophilic inflammation. METHODS: A competitive radioimmunoassay was used to detect serum levels of eosinophil cationic protein and EDN/EPX in 31 patients with vernal keratoconjunctivitis (VKC) and in 15 healthy controls. RESULTS: Mean serum levels of both eosinophil cationic protein and EDN/EPX were significantly higher in patients with VKC than in controls. There was a good correlation between serum levels of eosinophil cationic protein and EDN/EPX. No significant difference in mean serum eosinophil cationic protein levels was observed between patients with positive radioallergosorbent test (RAST) results and those with negative RAST results who have VKC, whereas mean EDN/EPX and total immunoglobulin E serum levels were significantly higher in patients with positive RAST results than in those with negative RAST results who have VKC. Serum eosinophil cationic protein, but not EDN/EPX, levels were significantly related to total immunoglobulin E levels. CONCLUSION: The authors' data indicate that serum levels of eosinophil cationic protein and EDN/EPX are useful markers of eosinophilic ocular inflammation in VKC.

Adolescent↗

Ultrastructural effects of PCMS on mycelial-yeast transition in Histoplasma capsulatum.

The Yeast phase of Histoplasma capsulatum has stringent growth requirements. Transition from mycelium to yeast takes place only in the presence of cysteine and can be blocked by the -SH groups inhibitor p-chloromercury-phenylsulfonic acid (PCMS). Ultrastructural studies show lysis and degeneration of PCMS treated mycelium grown at 37 degrees C for 24 hours. Only 50% of PCMS treated mycelium appear degenerate when grown at 34 degrees C for 24 hours. The remaining cells have normal morphology with only slight changes in the cell wall structure. The effect of PCMS is permanent and hereditary. Mice injected with PCMS treated mycelium do not develop disease and are resistant to virulent strains of H. capsulatum when challenged.

4-Chloromercuribenzenesulfonate↗

Aetiological association of virus like particles with hepatitis C.

Isolation of virus-like particles from sera of anti-HCV positive patients and their ultrastructural characterization are reported. Particles were identified in sera of 5 out of 6 patients tested. Immunoelectron microscopy assay revealed small aggregates of viral particles. Size and morphological criteria suggest that these particles can be classified as Togaviridae.

Hepacivirus↗

[Ultrastructural study of the yeast-mycelium transition in Histoplasma capsulatum. II. Changes at 34 degrees C].

The ultrastructural changes which occur during the mycelium to yeast transition in Histoplasma capsulatum induced by a temperature shift from 25 degrees C to 34 degrees C are described and compared to those observed after a temperature shift from 25 degrees C to 37 degrees C. 24 hours after the temperature shift to 34 degrees C only 8% of the cells are lysed. However, many mitochondria have lost their characteristic elongated form and have become rounded. Vesicular cristae which are no longer oriented parallel to the long axis of the mitochondria are also observed. In contrast a temperature shift from 25 degrees C to 37 degrees C induces lysis of 70% of the cells; mitochondria are rarely observed in the remaining cells. These ultrastructural changes can be correlated with the uncoupling of oxidative phosphorylation and the production of heat shock proteins.

Fungal Proteins↗

[The clinical, histological and ultrastructural findings in a case of acute steatosis of pregnancy with a severe cholestatic syndrome].

A case of acute steatosis in pregnancy featuring unusually severe cholestasis is discussed with details of the successful outcome for mother and foetus. The correspondence between clinical picture, histological and ultrasound findings is reported together with a detailed review of the latest reports in the literature and what they reveal about the true incidence of the disease, the variability of the clinical picture, whether and when it is better for both mother and child to interrupt.

Acute Disease↗

[Ultrastructural study of the mycelium-yeast transition in Histoplasma capsulatum. I. Changes at 37 degrees C].

Ultrastructural changes observed during the first 24 hours of mycelium to yeast transition in the dimorphic fungus Histoplasma capsulatum are reported. During this period the plasma membrane becomes undulated and the cell wall loses its characteristic fibrous outer layer. At 8 h the ordered lamellar structure of the mitochondria is no longer apparent. 24 h after the temperature shift 70% of the cells are lysed. The remaining cells contain many cytoplasmic membrane structures; mitochondria are rarely observed. These morphological changes are probably correlated with the physiological events characteristic of mycelial to yeast transition.

Cell Wall↗

Mycelium-yeast transition in Histoplasma capsulatum. Early ultrastructural changes.

The ultrastructural changes which occur during the first 24 h of mycelium to yeast transition have been studied in the dimorphic fungus Histoplasma capsulatum. A temperature shift controls mycelial to yeast transition. During the first 24 h respiratory rate, ATP and cytochrome concentration fall to very low levels. Ultrastructural observations showed that the plasma membrane became undulated and the cell wall lost its characteristic fibrous outer layer. At 8 h the ordered lamellar structure of the mitochondria was no longer apparent. 24 h after the temperature shift 70% of the cells were lysed. The remaining cells contained many cytoplasmic membrane structures; mitochondria were rarely observed. These changes are considered to be the morphological expression of the physiological events characteristic of stage one in mycelial to yeast transition.

Histoplasma↗

[Intranuclear particles in chronic non-A, non-B hepatitis: what diagnostic significance?].

Intranuclear particles of 23-27 nm diameter have been repeatedly demonstrated in the nuclei of hepatocytes of patients with non-A, non-B hepatitis and of experimentally infected chimpanzees; however, their specificity has been challenged since they have also been observed in other pathological conditions and in healthy volunteers. We have conducted an ultrastructural study of liver biopsies from 10 patients with chronic active non-A, non-B hepatitis. The intranuclear particles, which were observed in all patients, were classified according to the aggregation patterns described by De Vos. Eight patients (80%) had particles of type 2. A reevaluation our proceeding data on Delta hepatitis demonstrated that no particles of type 2 were present. These results support the hypothesis that only type 2 particles are markers of non-A, non-B hepatitis.

Adult↗

Prevalence of intranuclear particles in liver pathologies.

An ultrastructural study of the prevalence of electron dense 23-27 nm intranuclear particles was carried out on liver biopsies from patients with NANB chronic active hepatitis (CAH), Delta + CAH, HBsAg + CAH, nonviral liver pathologies and in one healthy volunteer. The particles were classified according to aggregation pattern and were found to be correlated with NANB CAH and Delta + CAH. No particles were observed in nonviral liver pathologies. A close antigenic relationship has been shown between the cytoplasmic alterations observed in NANB and delta hepatitis in chimpanzees. Our data indicate that there is a structural similarity between the intranuclear particles seen in both Delta and NANB hepatitis, thus reinforcing the hypothesis that the NANB and Delta agents are closely related.

Adult↗

[Unusual ultrastructural findings in a case of asymptomatic primary biliary cirrhosis].

The investigators report an ultrastructural study of a case of primary biliary cirrhosis histologically in stage II (Scheuer), a rare disease which has not been investigated extensively at the ultrastructural level. Biliary canaliculi are dilated and microvilli are scarce. Large granular formations are observed in the perisinusoidal cytoplasm. The plasma membrane between adjacent hepatocytes appears convoluted. The ultrastructural alterations of the biliary canaliculi which we observed have been described in the literature in cholestatic patients and ascribed to cholestasis. Our patients, however, has never suffered episodes of jaundice or itching and has no histological signs indicating cholestasis. We suggest that these are precocious alterations which precede the appearance of clinical and histological signs of cholestasis. It is necessary to study other cases in order to evaluate the significance of the large granular formations and the changes observed in the plasma membrane.

Adult↗

[Ultrastructural changes in hepatocytes of mice treated with morphine].

In a study of the ultrastructure of hepatocytes in mice treated with morphine a statistically significant increase in the volume density and surface density of smooth endoplasmic reticulum (SER) was observed. Morphometric measurements using the method described by Weibel (2,3) were employed to calculate volume density of smooth and rough endoplasmic reticulum mitochondria, and surface density of rough and smooth endoplasmic reticulum membranes and of the mitochondrial envelope and cristae. Statistical analysis using the t test of Student was carried out for all parameters. Both surface density and volume density of SER in mice treated with morphine increased significantly when compared to mice of control group (P less than 0.05 for surface density of smooth endoplasmic reticulum and P less than 0.01 for volume density of smooth endoplasmic reticulum). These ultrastructural changes after administration of morphine and related opiates are not accompanied by an increase of drug metabolizing enzymes and the huge tolerance observed in mice can be a phenomenon of adaptation at the receptor site (4).

Animals↗

[Ultrastructural changes in hepatocytes of mice treated with heroin].

In a study of the ultrastructure of a hepatocytes in mice treated with heroin a statistically significant increase in the volume density and surface density of smooth endoplasmic reticulum (SER) was observed. Morphometric measurements using the method described by Weibel (2,3) were employed to calculate volume density of smooth and rough endoplasmic reticulum and mitochondria, and surface density of rough and smooth endoplasmic reticulum membranes and of the mitochondrial envelope and cristae. Statistical analysis using the t test of Student was carried out for all parameters. Both surface density and volume density of SER in mice treated with heroin increased significantly when compared to mice of the control group. An increase in volume density of SER is generally believed to be correlated to an increase in drug metabolizing enzymes localized in or on smooth endoplasmic reticulum membranes. We have demonstrated a statistically significant increase in SER in mice treated with heroin which is not accompanied by an increase in drug metabolizing enzymes (7). We feel that further investigation of these anomalous cases is necessary in order to clarify the role of the SER membranes and their function in the metabolism of drugs.

Animals↗