Biomedical subjects

Keyvan Nouri

Publications and source records attributed to Keyvan Nouri.

At least 19 recordsLinked to original sources

PubMed2007

Laser treatment of keloids and hypertrophic scars.

BACKGROUND: Lasers have been used in the treatment of hypertrophic scars and keloids for more than 20 years. Different laser systems have been examined; among them pulsed dye lasers are currently considered the laser of choice in these settings. OBJECTIVES: The purpose of this study is to review the pertinent literature and provide updated information on different laser therapies available for treatment of keloids and hypertrophic scars. METHODS: A Medline literature search was performed for relevant publications. RESULTS: In this review the results of published studies in the treatment and prevention of hypertrophic scars and keloids are presented. Suggested mechanisms of action are reviewed. A review of the optimal laser parameters to modulate treatment outcome will be discussed. Different lasers are effective in not only the treatment but also the prevention of hypertrophic scars and keloids, among them PDL is more promising. Most of the suggested theories are based on the selective photothermolysis in which the light energy emitted from a vascular laser is absorbed by hemoglobin, generating heat and leading to coagulation necrosis, neocollagenesis, collagen fiber heating with dissociation of disulfide bonds and subsequent collagen fiber realignment. CONCLUSION: The optimal laser is currently 585 nm PDL, although the recent results of Q-switched 532 nm frequency-doubled Nd:YAG are promising. Early use of lasers are beneficial, especially in those who are prone to develop these lesions.

Cicatrix, Hypertrophic↗

PubMed2006

The treatment of melasma: a review of clinical trials.

Melasma is an irregular brown or grayish-brown facial hypermelanosis, often affecting women, especially those living in areas of intense UV radiation. The precise cause of melasma remains unknown; however, there are many possible contributing factors. Because of its dermal component and tendency to relapse, melasma is often difficult to treat. The use of broad-spectrum (UVA + UVB) sunscreen is important, as is topical hydroquinone, the most common treatment for melasma. Other lightening agents include retinoic acid (tretinoin) and azelaic acid. Combination therapies such as hydroquinone, tretinoin, and corticosteroids have been used in the treatment of melasma, and are thought to increase efficacy as compared with monotherapy. Kojic acid, isopropylcatechol, N-acetyl-4-cysteaminylphenol, and flavonoid extracts are other compounds that have been investigated for their ability to produce hypopigmentation, but their efficacy, safety, or trial design indicates that the interventions would need further study before they could be recommended. Chemical peels, laser treatments, and intense pulsed light therapy are additional therapeutic modalities that have been used to treat melasma.

Adrenal Cortex Hormones↗

PubMed2006

Muir-Torre syndrome: a case of this uncommon entity.

A 69-year-old Hispanic woman presented for the evaluation of nodules on the head and back. In the past, she had been treated for basal cell carcinoma (BCC) of the face; the referring physician was concerned that the new lesions might also be BCC. The patient had an extensive past medical history. In addition to BCC, she had been treated for breast cancer, colon cancer, and cervical cancer prior to emigrating to the USA. Her colonic malignancy had been localized proximal to the splenic flexure. She also had a history of colonic polyps and distal colonic villous adenoma. She denied ever being treated with radiation. Further details of her medical history and cancer staging were not available. Her family history was significant for a sister with colon cancer and transitional cell carcinoma of the urinary bladder. In addition, she had a great aunt with oral cancer and a great uncle with lung cancer. Neither the patient or her relatives had any history of tobacco use. On physical examination, in addition to scars from a radical mastectomy and midline abdominal laparotomy, four skin lesions were noted: two on the scalp, one on the tragus, and one on the mid-back. The first lesion on the vertex of the scalp was a yellow-brown waxy papule measuring 0.6 x 0.5 cm. This lesion was similar to that on the mid-back, except in size. The lesion on the back measured 1.2 x 1.0 cm. The second lesion on the frontal scalp measured 0.8 x 0.6 cm and was red-brown with a pearly appearance and some central hyperkeratosis. The tragus lesion was similar in appearance to that on the frontal scalp. Shave biopsies of all lesions were obtained. The lesions on the scalp and mid-back revealed lobules of sebaceous cells in the dermis with a minority of surrounding basaloid cells, consistent with a diagnosis of sebaceous adenoma (Fig. 1). Although the lesion on the frontal scalp also showed sebaceous differentiation, there were a greater number of basaloid cells, some with hyperchromatic nuclei and mitotic figures; this was consistent with a diagnosis of sebaceous epithelioma (Fig. 2). The final lesion (tragus) was histologically consistent with a keratotic BCC. No further treatment was required for these benign sebaceous tumors, but their presence defined our patient's condition as Muir-Torre syndrome. Mohs' micrographic surgery was performed on the tragus BCC and the margins were tumor free in one stage. The patient returned 1 year later with a lesion anterior to the left axilla which was biopsied to rule out BCC (Fig. 3). Histologically, this lesion was also consistent with sebaceous epithelioma.

Adenoma↗

PubMed2006

Laser treatment for pigmented lesions: a review.

BACKGROUND: Just a few decades ago, before lasers were introduced into dermatologic practice, many cutaneous lesions were untreatable. Since the introduction of lasers in dermatology in the 1960s and its revolution by Anderson and Parrish in the 1980s based on the selective photothermolysis theory, lasers have become a main component of many dermatology practices. With the advent of these selective lasers and their constant technological advancements, many lesions can now be easily removed with a low incidence of complications, creating a high demand for laser surgery. Aims This paper will review current laser systems used for pigmented lesions. METHODS: An English-language literature search and review through Medline from January 1994 to October 2004. Review of the latest techniques and lasers used in treating pigmentary disorders and possible future applications and treatment options. CONCLUSIONS: Laser technique and technology has greatly advanced producing more effacious treatment with minimal complications.

Humans↗

PubMed2006

Lasers for scars: a review.

Many articles have been published on improving the appearance of scars; however, there are no definitive management protocols. Our objective was to review the literature on laser therapy for various types of scars. There are multiple laser modalities that have been studied with certain features that may be indicated for specific scar types. Suggestions are given for further studies.

Atrophy↗

PubMed2006

Nonablative lasers.

The trend toward minimally invasive rejuvenation techniques has led to the widespread use of nonablative lasers. Nonablative lasers can be classified in two groups based on their wavelengths: lasers emitting light in the visible range, and those emitting in the infrared range. In this review, different laser and intense pulsed light (IPL) systems are presented and critically discussed along with findings of the studies in the literature.

Humans↗

PubMed2006

Difference between pigmented and nonpigmented basal cell carcinoma treated with Mohs micrographic surgery.

BACKGROUND: There have been several articles characterizing cases of pigmented basal cell carcinomas (PBCC). Previous studies have also evaluated the relationship between histologic pattern and frequency of basal cell carcinoma (BCC) associated with pigment formation. No specific studies, however, have examined the subclinical extension and surgical margins of PBCC tumors. OBJECTIVE: A prospective study of 345 Mohs micrographic BCC surgical cases revealed 67 PBCC cases. Analysis of patient details included patient age and sex, the lesional site, histologic subtype, tumor size, final surgical margin, and the number of stages required to achieve tumor-free margins together with the presence or absence of pigment. METHODS: This study was performed between May 2004 and January 2005 at the Department of Dermatology and Cutaneous Surgery, University of Miami, Mohs Surgery Center. RESULTS: Total mean surgical margin was smaller in the PBCC than the nonpigmented BCC (NPBCC) group (3.89 mm vs. 5.85 mm; p<0.05). In lesions less than 2 cm in size, there were even more significant differences between the two groups (3.32 mm vs. 5.33 mm; p<0.05), and also between the aggressive and nonaggressive histologically diagnosed groups (3.13 mm vs. 5.01 mm; p<0.05). CONCLUSIONS: We have demonstrated that PBCC requires a smaller surgical margin for complete tumor excision than NPBCC, especially in smaller tumors and in the nonaggressive histologic subtype group. Treatment within the early growth stages also involves less subclinical microscopic invasion and a smaller surgical margin in PBCC.

Aged↗

PubMed2006

The incidence of recurrent herpes simplex and herpes zoster infection during treatment with arsenic trioxide.

We report the incidence of varicella zoster virus (VZV) and herpes simplex virus (HSV) infection in patients with multiple myeloma and colon cancer who were treated with arsenic trioxide for their disease. In this report, we discuss the effects of arsenic on immune system, and suggest arsenic compounds as a possible predisposing factor for viral reactivation in these patients.

Aged↗

PubMed2005

Effect of the 1,450 nm diode non-ablative laser on collagen expression in an artificial skin model.

BACKGROUND AND OBJECTIVE: The 1,450-nm Smoothbeam Laser is a diode laser equipped with a cryogen cooling spray. Primary objectives were to evaluate the effects of this non-ablative laser on Apligraf (bioengineered skin-substitute) and to document its use as a model for non-ablative procedures. We also measured the effects of laser fluence levels on collagen and elastin expression. STUDY DESIGN/MATERIALS AND METHODS: Three sheets of Apligraf were used for this study. Each received six separate laser applications at 4J, 6J, 8J, 10 J, 12J, and 14J. The sheets were then incubated with 10% CO(2) at 37 degrees C and samples were collected and analyzed 3 days later, using RT-PCR and immunofluorescent staining. RESULTS: Collagen III expressions significantly increased in both mRNA and protein levels at approximately 12 J. CONCLUSIONS: There appears to be a threshold effect where there is very little increased collagen III mRNA and protein expression until the laser fluence reaches around 12J.

Collagen↗

PubMed2005

Light/laser therapy in the treatment of acne vulgaris.

Acne vulgaris is one of the most prevalent skin diseases known. As common as this condition is, the social and psychological consequences are limitless. Although current treatments are available and include topical or oral antibiotics, it is crucial to develop a less risky and more effective therapy such as light/laser therapy. This article focuses specifically on the benefits of the light/laser treatment on acne vulgaris. Porphyrins accumulated in the bacteria, Propionibacterium acnes, one of the etiologic factors involved in the pathogenesis, allows phototherapy to be a successful modality. They have specific absorption peaks at which lasers have optimal effects. The longer the wavelength of the light is, the deeper its penetration and thus the greater its damage to the sebaceous glands. Although blue light is best for the activation of porphyrins, red light is best for deeper penetration and an anti-inflammatory effect. Ultraviolet (UV) light, although it may have initial an anti-inflammatory effects, has been proven to be potentially carcinogenic and have adverse effects such as aging (by UV-A) and burning (by UV-B). Previous studies indicate successful long-term intervention and selective damage of the sebaceous glands by using a diode laser with indocyanine green (ICG) dye. Mid-infrared lasers have been found to decrease lesion counts while also reducing the oiliness of skin and the scarring process. Nonablative laser treatment of acne scars using the Er:YAG laser with a short-pulsed mode has been successful in reducing the appearance of scars by stimulating neocollagenesis. The light/laser therapy has started to be explored with promising results in highly selected patients that require further investigation in greater populations and well-designed protocols.

Journal Article↗

PubMed2005

Double-blind, randomized, placebo-controlled, prospective study evaluating the tolerability and effectiveness of imiquimod applied to postsurgical excisions on scar cosmesis.

BACKGROUND: It has been reported that topical application of imiquimod 5% cream induces interferon-alpha, an antifibrotic cytokine. OBJECTIVE: To determine the tolerability and effectiveness on the cosmetic outcome of the application of imiquimod to postsurgical excision sites. MATERIALS AND METHODS: A prospective, double-blinded, randomized, vehicle-controlled trial was conducted among 20 patients with two skin lesions clinically diagnosed as melanocytic nevi. Imiquimod 5% cream was applied to one of the sutured surgical wounds starting the night of the excision nightly for a period of 4 weeks. The second sutured excision site was treated with vehicle cream. Scar cosmesis, erythema, pigmentary alterations, induration, tenderness, and pain were assessed using a visual analogue scale 2, 4, and 8 weeks after surgery. RESULTS: Eighteen subjects completed the study, with a total of 36 excision sites; no wound site dehisced, and no signs of infection were noted. Surgical wounds treated with imiquimod had more erythema, pigmentary alterations, and lower cosmesis rated by the investigator compared with wounds treated with placebo, both becoming nonsignificant in further evaluations. For pigmentary alterations, induration, and cosmesis rated by the patients, no statistically significant difference between treatment groups was observed at week 8. CONCLUSION: Treatment of surgical excision-site wounds with imiquimod was well tolerated and without serious adverse events. Evaluations for cosmesis of placebo-treated surgical sites were better than imiquimod-treated sites at week 8, becoming nonsignificant later.

Adolescent↗

PubMed2005

Cotton-tipped applicators used in surgery of the nose.

BACKGROUND: A variety of uses have been described for cotton-tipped applicators. OBJECTIVE: We describe an additional application in surgeries involving the nose. This technique uses 8-inch obstetrics-gynecology applicators with oversized cotton tips, unlike most articles, which report the use of 6-inch applicators with smaller cotton heads. The applicators function to stabilize and support the nasal structures and thus provide a steadier operating field. CONCLUSION: It can be used in procedures of the nose, including curettage, electrocautery, hemostasis, and Mohs and other surgical excisions.

Cotton Fiber↗

PubMed2005