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Biomedical subjects

M M Christian

Publications and source records attributed to M M Christian.

12 recordsLinked to original sources
PubMed2001

A correlation of alpha-smooth muscle actin and invasion in micronodular basal cell carcinoma.

BACKGROUND: Actin is largely responsible for cell motility and is only sparsely found in normal epithelial cells. An altered expression of actin in some malignancies may facilitate aggressive invasion. Micronodular basal cell carcinoma (BCC) has been shown to require more surgical stages, wider tissue margins, and deeper defects for extirpation during Mohs micrographic surgery relative to nodular BCC. OBJECTIVE: To provide preliminary data regarding a possible correlation between alpha-smooth muscle actin (alpha-SMA) expression within the cells or stroma of micronodular BCC and aggressive invasion. In addition, the incidence of alpha-SMA expression in micronodular, morpheaform, and nodular BCC is evaluated. METHODS: Nine micronodular basal cell carcinomas (7 primary, 2 recurrent) were evaluated for neural invasion, depth of tissue invasion, and alpha smooth muscle actin antibodies. The presence of alpha-smooth muscle actin antibodies was assessed using immunoperoxidase staining and compared with 13 morpheaform (13 primary, 0 recurrent) and 12 nodular (12 primary, 0 recurrent). RESULTS: Six of the nine micronodular (67%), eight of the 13 morpheaform (62%), and 0 of the 12 nodular (0%) BCCs stained positive for alpha-SMA. Of the six micronodular BCCs that stained positive for alpha-SMA, three invaded the fascia or muscle and three displayed neural invasion. In contrast, of the three micronodular BCCs that stained negative for alpha-SMA, none invaded the fascia or muscle and only one exhibited neural invasion. CONCLUSION: Actin was present in 66% of micronodular, 62% of morpheaform, and 0% of nodular BCC. The presence of actin in micronodular BCC may be a marker for aggressive invasion.

Actins↗
PubMed2001

Ocular damage due to chlorhexidine versus eyeshield thermal injury.

BACKGROUND: Ocular damage may occur from a number of mechanisms during laser use. OBJECTIVE: To review issues relevant to ocular protection during laser resurfacing. METHODS: The authors were consulted to evaluate the thermal energy transferred from the outer to the inner (ie, corneal contact) surface of stainless steel eyeshields following direct exposure to the carbon dioxide (CO2) resurfacing laser beam. Measurements were obtained using thermocouples (attached to the inner surface of the eyeshields) and analyzed with a computer-based acquisition system. RESULTS: A maximum eyeshield temperature increase of 13 degrees C above the ambient temperature was noted following one pass with a CO2 resurfacing laser (Sharplan continuous CO2 laser with Clinicon SureScan scanner, 15 W, 950 microsec pulse duration, square spot of 9 mm). CONCLUSION: The eyeshields analyzed in this study minimized thermal transfer following a single direct hit with a CO2 resurfacing laser. An understanding of the potential mechanisms of ocular injury is essential in preventing its occurrence.

Anti-Infective Agents, Local↗
PubMed2001

Langerhans cell histiocytosis in a child while in remission for acute lymphocytic leukemia.

The occurrence of Langerhans cell histiocytosis (LCH) and malignancy in the same patient is rare. When LCH occurs concomitantly with acute leukemia, distinct temporal patterns often exist; acute myelogenous leukemia (AML) typically succeeds LCH, whereas acute lymphocytic leukemia (ALL) usually precedes it. We report a case of LCH developing in a child while in remission for ALL. Unique features of this case include the disseminated nature of the LCH and the death of the patient from LCH rather than ALL.

Back↗
PubMed2000

Delayed infections following full-face CO2 laser resurfacing and occlusive dressing use.

BACKGROUND: Carbon dioxide (CO2) laser resurfacing has become an increasingly popular procedure for the treatment of facial rhytides and solar damage. Yet despite ongoing advancements in laser technology, CO2 laser resurfacing is still a risk-laden procedure that may lead to complications such as infection. Occlusive dressings increase the healing rate and decrease pain intensity in patients who receive full face laser resurfacing. It has been said that the use of occlusive dressings in postresurfacing patients may increase the risk of infection, which typically presents 2-10 days after the procedure. OBJECTIVE: The purpose of this article is to report the incidence of infection following full-face CO2 laser resurfacing of 354 patients who were treated with occlusive dressings. In addition, factors which may have contributed to the delayed onset in three of the four infections are discussed. METHODS: Three hundred fifty-four patients received full-face CO2 laser resurfacing. Either a continuous wave CO2 laser with a computer-generated scanner (396 microseconds dwell time, 18 W) or a pulsed CO2 laser (500 mJ pulse energy, 90 microseconds pulse duration) were used in all cases of resurfacing. Postoperatively all patients were treated with occlusive dressings and empiric oral cephalexin. Postoperatively patients were monitored at weekly intervals during the first month and then at 3 and 6 months. RESULTS: Of the 354 patients who received full-face laser resurfacing, there were 4 cases of culture-proven infection, which translates to an infection rate of 1.13%. Three of the four infections developed 3-5 weeks after the procedure. CONCLUSION: This study reports an infection rate of 1.13% following full-face CO2 laser resurfacing and occlusive dressing use in 354 patients. Because infection may develop many weeks after the procedure, patients should be educated to maintain proper wound care hygiene and to avoid "double dipping" of wound care products until wounds are completely healed.

Aged↗
PubMed2000

Short-pulse carbon dioxide laser resurfacing of the neck.

BACKGROUND: Carbon dioxide (CO(2)) laser resurfacing of the face has become an increasingly popular procedure. However, laser resurfacing of the neck has been largely avoided because of fears of scarring or pigmentation changes. OBJECTIVE: Our purpose was to evaluate the efficacy of treatment and incidence of complications after short-pulse CO(2) laser resurfacing of the neck. METHODS: A total of 308 patients received concomitant face and neck CO(2) laser resurfacing. A 90 -micros pulse duration CO(2) laser without a scanner was used in all cases for 2 passes on the neck (10.6-microm wavelength, 500-mJ pulse energy, 90-micros duration, 3-mm spot size) and a continuous CO(2) laser with a computer-generated scanner (396-micros dwell time, 18 W) was used for 3 passes over the face except for the perioral area, which received 4 passes. The incidence of scarring or permanent pigmentation changes was determined. Forty patients who had been treated at least 6 months but no longer than 18 months earlier were randomly surveyed by phone to assess the degree of improvement. RESULTS: Of the 308 patients treated, there were no cases of scarring or permanent pigmentation changes. Surveyed patients reported a 39% improvement in rhytides and tightening on the neck. CONCLUSION: Resurfacing of the neck can be performed safely in conjunction with resurfacing of the face. Patients may be offered improvement in the neck with little chance of scarring or permanent pigmentary changes when resurfacing on the neck is performed by means of a short-pulse duration laser for a limited number of passes instead of the more aggressive laser parameters previously used such as continuous long-pulse duration treatments.

Adult↗
PubMed1999

Hair removal using the long-pulsed ruby laser.

The long-pulsed ruby laser is a faster, more effective method for the removal of unwanted hair compared to older, temporary techniques like shaving, waxing, and chemical depilation. It is the only laser approved by the FDA for permanent hair removal. Patients experience minimal pain and side effects, observe immediate hair growth delay, an increase in vellus hairs, and have the potential for permanent hair removal. Although treatment sessions can be lengthy, the laser is easy to operate and the cooled handpiece allows patients to easily tolerate long sessions.

Hair Removal↗
PubMed1999

Treatment of Hailey-Hailey disease (or benign familial pemphigus) using short pulsed and short dwell time carbon dioxide lasers.

BACKGROUND: Surgical intervention of Hailey-Hailey disease (HHD) may be required to achieve prolonged remission or cure. Excisional surgery, dermabrasion, and continuous carbon dioxide (CO2) laser therapies have been utilized with success, though patients may experience considerable morbidity. OBJECTIVE: To evaluate the use of short pulsed and short dwell time CO2 lasers in the treatment of HHD. METHOD: Case report and review of the relevant literature. RESULTS: A 26-year-old woman with refractory axillary HHD was initially treated with a short dwell time CO2 laser. The right axilla was treated with two passes at a fluence of 25 J/cm2, and the left axilla with three passes at 28 J/cm2. Three years later, several foci within each axilla that periodically blistered were further treated with two passes of a short pulsed CO2 laser at a fluence of 15 J/cm2. At a 3.5-year follow-up, the patient reported continued resolution of her left axilla but disease persistence in her right axilla. CONCLUSION: HHD can be effectively treated with a short dwell time CO2 laser if appropriate laser parameters are used.

Adult↗
PubMed1998

Metastatic basal cell carcinoma presenting as unilateral lymphedema.

BACKGROUND: Metastatic basal cell carcinoma (MBCC) is rare, occurring in only 0.0028-0.55% of all basal cell carcinomas (BCCs). Patients with MBCC may present with a variety of findings, related to the site of metastasis. OBJECTIVE: Clinical presentation of a MBCC that became symptomatic due to unilateral lymphedema and a review of the relevant literature. METHODS: Case report with literature review. RESULTS: Patients may present with lymphadenopathy, ulcerations, anemia, bone pain, or muscle weakness related to the site of metastasis. In this reported case, MBCC presented as unilateral lymphedema. Risk factors for MBCC include radiation, large and invasive tumors, and a history of recurrence. The average survival time for localized lymph node metastasis in BCC is 3.6 years. This patient is currently 2 years since MBCC presentation and is currently without evidence of recurrence. CONCLUSION: To our knowledge, we report the first case of MBCC that presented as unilateral lymphedema.

Aged↗
PubMed1992

A correlation with type of sulfonamide resistance gene in Escherichia coli and synergy between trimethoprim and sulfamethoxazole.

Plasmids carrying type I or II sulfonamide-resistance (Sur) genes were evaluated for their effect on synergy between trimethoprim (Tmp) and sulfamethoxyzole (Smx) in E. coli. Strain J53 containing each of three plasmids (R1, pSa, and R388) with the type I Sur gene displayed a synergistic response to Tmp/Smx; strain LE392 containing a plasmid (RSF1010) with the type II Sur gene displayed no synergy. The difference in synergy between type I and type II Sur genes might be explained by the difference in amount of resistant enzyme produced.

Drug Synergism↗