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G Moussa

Publications and source records attributed to G Moussa.

15 recordsLinked to original sources
PubMed2006

Evaluation of the epidermal refractive index measured by optical coherence tomography.

BACKGROUND/AIMS: It has recently been proposed that the refractive index (RI) measured by means of optical coherence tomography (OCT) may be a valid measure for hydration of skin. In this pilot study, using OCT in vivo, we aimed to investigate the interday variability of RI measurements and acute changes of RI following the application of a moisturizer. METHODS: Twenty healthy Caucasian volunteers were investigated on their forearms using a commercially available OCT system (SkinDex 300, ISIS optronics GmbH, Mannheim, Germany) fitted with an integrated algorithm for the evaluation of the RI. The interday repeatability of the OCT method was determined performing symmetrical measurements on both forearms on day 1, 5, 9, and 13. In order to investigate the acute effect of a moisturizer on RI, OCT assessments were performed before and 10 min after the application of an aqueous lotion with a lipophilic phase. As a control, the contralateral site was investigated in the same way, except for the use of distilled water instead of the lotion. RESULTS: Assessments of interday variability revealed insignificant (P>0.05) variances between the four measurement times as expressed in very small repeatability coefficients (right arm: 0.039; left arm 0.053) and small coefficients of variance (right arm: 1.02%; left arm: 1.38%). With regard to the RIs measured over time, we could not observe significant (P>0.05) differences between the two symmetrical anatomic sites (mean+/-SD of RI: 1.3893+/-0.0142 (right arm); 1.3875+/-0.0192 (left arm)). The acute effect of the moisturizer was indicated by a significant decrease of the RI 5 min after the application of the lotion (1.399+/-0.01 vs. 1.387+/-0.02; difference between means: 0.012; P=0.033; 95% confidence interval: 0.001-0.0023). However the control site treated with distilled water did not show significant differences between the two measurement times (1.387+/-0.013 vs. 1.391+/-0.023; difference between means: -0.004; P=0.57; 95% confidence interval: -0.019-0.011). CONCLUSIONS: In this pilot study, we have demonstrated that RI evaluation via OCT is a promising technique that may be used for the assessment of skin hydration in vivo. However, the direct comparison of OCT with standard methods, ideally such as nuclear magnetic resonance spectroscopy, is necessary.

Adult↗
PubMed2006

Epidermal thickness assessed by optical coherence tomography and routine histology: preliminary results of method comparison.

BACKGROUND: Optical coherence tomography (OCT) is a promising non-invasive imaging technique for studying the epidermis and upper dermis in vivo. As proposed previously by Welzel et al. (J Am Acad Dermatol 1997; 37: 958-963), distance measurements between the entrance peak and the second peak of the A-scan seem to correspond to epidermal thickness (ET). However, there is a lack of systematic studies comparing OCT with histology. METHODS: Sixteen healthy subjects were included in this pilot study. OCT assessments were conducted on the upper back. To determine ET by OCT, the distance between the entrance peak and the second peak of the A-scan was calculated (ET-OCT). After OCT measurement a 4 mm punch biopsy was taken on each subject from the same site previously assessed. The maximum thickness of the epidermis (ET-Histo) was determined microscopically using routine histological slices (formalin-paraffin technique, haematoxylin-eosin staining). Correlation and agreement between the two methods were assessed by means of the Pearson correlation procedure and Bland-Altman plots, respectively. RESULTS: ET-Histo was 79.4 +/- 21.9 microm, including a stratum corneum thickness of 20 +/- 12.1 microm. OCT measurements resulted in an ET of 106 +/- 15.4 microm. No correlation between ET-Histo and ET-OCT was observed (r = 0.29, P = 0.27). There was a considerable lack of agreement between histology and OCT measurements as expressed in a high bias of 26.63 microm [95% confidence interval (CI) 14.49-38.77]. Furthermore, the lower 95% limits of agreement were -18.03 microm (95% CI -37.11 to 1.05) and the upper 95% limits of agreement were 71.28 microm (95% CI 52.2-90.36) indicating that ET-OCT may be 71.28 microm above or 18.03 microm below ET-Histo. CONCLUSIONS: Our preliminary data suggest that the above-described OCT algorithm is probably not a valid measure for the evaluation of ET. The second peak of the A-scan seems not to correspond to the dermo-epidermal junction zone, but rather to fibrous structures in the upper dermis. Nevertheless, further systematic comparison studies between OCT and histology are warranted, using different OCT algorithms for ET determination and cryopreparation, which has a higher reliability than the formalin-paraffin technique.

Adult↗
PubMed2005

UVA1 and UVB irradiated skin investigated by optical coherence tomography in vivo: a preliminary study.

In histological studies, it has frequently been demonstrated that ultraviolet (UV) exposure, in particular UVB, can induce significant thickening of the viable epidermis and/or stratum corneum. Since skin biopsy alters the original skin morphology and always requires an iatrogenic trauma, we aimed to introduce optical coherence tomography (OCT) in vivo for the investigation of changes of epidermal thickness (ET) following UVA1 and UVB irradiation. Twelve healthy subjects received daily 60 J/cm2 of UVA1 and 1.5 minimal erythema doses UVB on their upper back over 3 consecutive days. Twenty-four hours after the last irradiation, OCT assessments were performed on UV exposed and adjacent nonirradiated control sites. Data of ET as expressed by comparison of the averaged A-scans differed significantly between nonirradiated (94.2 +/- 15.7 microm), UVA1 (105.4 +/- 12.8 microm) and UVB (125.7 +/- 22.1 microm) exposed sites. In comparison to the nonirradiated sites, UVA1 exposed skin showed significant (P = 0.022) increase of ET of 11% and UVB exposed sites a significant (P < 0.001) increase of 25%. ET of UVA1 and UVB exposed skin sites differed significantly (P =0.005). Our results obtained from OCT in vivo measurements confirm data of previous histological studies indicating that not only erythemogenic doses of UVB, but also suberythemogenic doses of UVA1 may have a significant impact on ET. OCT appears to be a promising bioengineering technique for photobiological studies. However, further studies are needed to establish its measurement precision and validity, and to investigate in vivo spectral dependence on UV induced skin changes such as skin thickening.

Adult↗
PubMed2001

A randomised trial comparing cytomegalovirus antigenemia assay vs screening bronchoscopy for the early detection and prevention of disease in allogeneic bone marrow and peripheral blood stem cell transplant recipients.

Preemptive antiviral therapy is often employed for CMV prevention following allogeneic BMT. Two common strategies are a screening bronchoscopy for CMV post-BMT or regular CMV antigenemia testing with ganciclovir administration for a positive result. In a randomised trial, we prospectively compared the efficacy of these two preemptive strategies. Consecutive patients were randomised to either a bronchoscopy for CMV on day 35 post BMT or weekly CMV antigenemia testing. If the bronchoscopy was positive for CMV, patients received preemptive ganciclovir for 8-10 weeks. If the antigenemia was positive for CMV, patients received a minimum of 2 weeks of preemptive ganciclovir. The primary endpoint was the development of active CMV disease. One hundred and eighteen allogeneic BMT patients were enrolled (60 in the antigenemia arm and 58 in the bronchoscopy arm). The two groups were comparable with respect to baseline demographic data, underlying disease, conditioning regimen, and immunosuppression. Active CMV disease developed in 7/58 (12.1%) patients in the bronchoscopy arm vs 1/60 patients (1.7%) in the CMV antigenemia arm (P = 0.022). Based on the screening test, 13.8% of patients received preemptive ganciclovir in the bronchoscopy arm vs 48.3% of patients in the antigenemia arm (P < 0.001). There was no significant difference in the rate of graft-versus-host disease, bacteremia, invasive fungal infections or mortality between the two groups. Preemptive therapy based on regular CMV antigenemia monitoring is superior to screening bronchoscopy for the prevention of CMV disease after allogeneic BMT.

Adult↗
PubMed2000

Human herpesvirus-6 is associated with cytomegalovirus reactivation in liver transplant recipients.

Human herpesvirus-6 (HHV-6) may be a risk factor for cytomegalovirus (CMV) disease in posttransplant patients, possibly through a direct interaction or through a general immunomodulatory effect. To examine this possibility, 88 liver transplant recipients were monitored with serial HHV-6 polymerase chain reaction (PCR), CMV antigenemia, and CMV plasma viral load. HHV-6 infection was defined by a positive PCR of peripheral blood lymphocytes. Forty-eight (54.4%) of 88 patients had at least 1 positive HHV-6 PCR. CMV recurrence was significantly more common in patients with HHV-6 infection (38/48 patients [79. 2%]), compared with recurrence in those without HHV-6 infection (18/40 patients [45%]; P=.001). Peak CMV viral load was 24, 147+/-6799 copies/mL in patients with HHV-6 infection versus 8391+/-4598 copies/mL in patients without HHV-6 infection (P=.001). Symptomatic CMV disease was more common in patients with HHV-6 infection than it was in those without infection (15/48 patients [31. 3%] vs. 4/10 patients [10.0%]; P=.013). In a multivariate analysis including other risk factors for CMV, HHV-6 infection remained an independent risk factor for CMV disease (P=.013; odds ratio, 7.26; 95% confidence interval, 1.52-34.72). HHV-6 is associated with CMV infection and disease, thus supporting an interaction between these viruses.

Adolescent↗
PubMed1999

The clinical utility of CMV surveillance cultures and antigenemia following bone marrow transplantation.

At our institution, the cytomegalovirus (CMV) prophylaxis protocol for allogeneic bone marrow transplant (BMT) recipients who are CMV-seropositive or receive marrow from a CMV-seropositive donor consists of a surveillance bronchoscopy approximately 35 days posttransplant. Patients with a positive surveillance bronchoscopy for CMV receive pre-emptive ganciclovir. In order to determine the utility of other screening methods for CMV, we prospectively performed weekly CMV antigenemia, and blood, urine and throat cultures from time of engraftment to day 120 post-BMT in 126 consecutive patients. Pre-emptive ganciclovir was given to 11/81 patients (13.6%) because of a positive surveillance bronchoscopy for CMV. Results of CMV blood, urine and throat cultures and the antigenemia assay done prior to or at the time of the surveillance bronchoscopy were analyzed for their ability to predict the bronchoscopy result. The antigenemia test had the highest positive and negative predictive values (72% and 96%, respectively). The ability of these tests to predict CMV disease was evaluated in the 70 patients with a negative surveillance bronchoscopy who did not receive pre-emptive ganciclovir. Of 19 cases of active CMV disease, CMV antigenemia was positive in 15 patients (79%) a mean of 34 days preceding symptoms. Blood cultures were positive in 14/19 patients (74%) a mean of 31 days before onset of disease. CMV antigenemia is useful for predicting the surveillance bronchoscopy result, and also predicts the development of CMV disease in the majority of patients missed by the surveillance bronchoscopy.

Adolescent↗
PubMed1999

Multicenter comparison of the digene hybrid capture CMV DNA assay (version 2.0), the pp65 antigenemia assay, and cell culture for detection of cytomegalovirus viremia.

We compared the Digene Hybrid Capture CMV DNA Assay version 2.0, the pp65 antigenemia assay, traditional tube culture, and shell vial culture for the detection of cytomegalovirus (CMV) viremia in several patient populations at three centers. Of 561 blood specimens collected from 402 patients, complete clinical and laboratory data were available for 489. Using consensus definitions for true positives and true negatives, the sensitivities of the Hybrid Capture assay, antigenemia, shell vial, and tube culture were 95, 94, 43, and 46%, respectively. The specificities of the Hybrid Capture assay and antigenemia were 95 and 94%, respectively. At all three study sites, the detected level of CMV viremia was significantly higher with the Hybrid Capture assay or antigenemia than with shell vial and tube culture. In a group of 131 healthy nonimmunosuppressed volunteers, the Hybrid Capture assay demonstrated a specificity of over 99%. The Hybrid Capture assay is a standardized assay that is simple to perform and can utilize whole blood specimens that have been stored for up to 48 h. The high sensitivity and specificity of the Hybrid Capture assay along with its simplicity and flexibility make it a clinically useful assay for the detection of CMV viremia in immunocompromised or immunosuppressed patients. Further evaluation to determine its role in predicting CMV disease and for monitoring the therapeutic response to anti-CMV therapy is needed.

Adolescent↗
PubMed1996

Refractory anaphylactoid shock potentiated by beta-blockers.

Allergic reactions, including anaphylactoid shock due to contrast material, are not uncommon. However, persistent anaphylactoid shock refractory to conventional therapy is rare. We present a case of refractory anaphylactoid shock during coronary angiography unresponsive to aggressive standard therapy in a patient on beta-blockers. Significant clinical improvement was noted upon administration of glucagon. Since beta-blockers are commonly used in patients with coronary artery disease, this potentially life-threatening complication has to be kept in mind with any procedure involving contrast media in patients on beta-blockers. Immediate access to glucagon by keeping it in the procedure room may be lifesaving in these situations.

Adrenergic beta-Antagonists↗
PubMed1994

The Osborn wave of hypothermia in normothermic patients.

The Osborn wave (also referred to as "the J wave," "the J deflection," or "the camel's hump") is a distinctive deflection occurring at the QRS-ST junction of approximately 80% of hypothermic patients (core body temperature < or = 95 degrees F). Generally, the amplitude and duration of Osborn waves are inversely related to core temperature. We report on eight normothermic patients whose 12-lead electrocardiograms demonstrated QRS-ST junction notches similar to those seen in hypothermia. These data support the concept that the Osborn wave is not pathognomonic of hypothermia.

Adult↗
PubMed1992

[Anterior lenticonus, suggesting Alport syndrome. Apropos of a first case in Zaire].

Anterior lenticonus is a rare condition, in which there is a conical or spherical protrusion of the anterior surface into the anterior chamber. This is demonstrated by this case report, which has not been previously described in the Black African or Zairian ophthalmological literature. The patient was 28 years old and complained of gradual deterioration of vision over several years. The visual acuity was 20/200. The slit lamp biomicroscope showed an anterior lenticonus with microopacities of the lens. On fundus examination, a fundus albipunctatus-like appearance with midperipheral retinal flecks and macular hole were found. The presence of associated ocular abnormalities, deafness and hematuria, is suggestive of Alport's syndrome.

Adult↗
PubMed1992

Conjunctival rhinosporidiosis. Report of three cases from Zaire.

The authors report three cases of conjunctival rhinosporidiosis from Zaire, two of which are believed to be the first documented in the northeastern part of the country. All patients were males. Two patients were very young children, respectively 5 and 6 years old. The third patient was a 35-year-old man. The diagnosis was based on histopathology which revealed the characteristic features of Rhinosporidium seeberi. Total excision was the elective treatment. The disease recurred eleven months later in one case, probably from local dissemination of the parasite during surgery.

Adult↗
PubMed1990

Lymphomatoid granulomatosis presenting as ulcerodestructive gastrointestinal tract lesions in patients with human immunodeficiency virus infection. A new association.

We describe cases of severe odynophagia, extensive oral ulcerations, and bowel perforation in patients with human immunodeficiency virus infection that were caused by lymphomatoid granulomatosis. Such presentations in human immunodeficiency virus-infected individuals are usually ascribed to other causes and may be incorrectly treated on an empiric basis. In addition, deep tissue specimens obtained at the margin of ulcerative lesions are often necessary for definitive diagnosis. We review our limited treatment experience with zidovudine, interferon alfa, and H2 blockers in our patients. Based on the markedly increased frequency in which lymphomatoid granulomatosis is being diagnosed at our institution in the post-human immunodeficiency virus era, we postulated an association between these two entities.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Reference limits for erythema-effective UV doses.

Diagnostic phototesting, including the determination of the minimal erythema dose (MED), is a useful procedure to detect abnormal sensitivity to UV radiation. We aimed to estimate the reference limits (RLs) of the MED in a reasonably large reference sample of white individuals. Skin phototypes and MED values for broadband UVB and for UVA were determined in 461 white subjects. When appropriate, the 95% reference intervals, including the 0.025 fractile and 0.975 fractile, were computed for the MED-UVB reference values (by means of parametric methods) and the MED-UVA reference values (by means of nonparametric methods). MED data were also converted to standard erythema doses (SEDs). As described elsewhere we observed a considerable overlap of MED values for all skin phototypes and confirmed that age and sex do not substantially influence the MED. The lower RLs observed for MED-UVB were 33 mJ cm(-2) (0.5 SEDs) and for MED-UVA 12.6 mJ cm(-2) (1.2 SEDs). The MED and SED findings from this investigation may serve as reference data for white individuals and give support to the clinician in differentiating between normal and pathologically abnormal photosensitivity. Although the MED data given here are limited to the phototest device used in the present study, the SED results establish comparability between our data and phototest results obtained from laboratories using different UV sources.

Adolescent↗