Studies on the motility of the foraminifera. II. The dynamic microtubular cytoskeleton of the reticulopodial network of Allogromia laticollaris.

Lamellipodia have been induced to form within the reticulopodial networks of Allogromia laticollaris by being plated on positively charged substrata. Video-enhanced, polarized light, and differential interference contrast microscopy have demonstrated the presence of positively birefringent fibrils within these lamellipodia. The fibrils correspond to the microtubules and bundles of microtubules observed in whole-mount transmission electron micrographs of lamellipodia. Microtubular fibrils exhibit two types of movements within the lamellipodia: lateral and axial translocations. Lateral movements are often accompanied by reversible lateral associations between adjacent fibrils within a lamellipodium. This lateral association-dissociation of adjacent fibrils has been termed 'zipping' and 'unzipping'. Axial translocations are bidirectional. The axial movements of the microtubular fibrils can result in the extension of filopodia by pushing against the plasma membrane of the lamellipodia. Shortening, or complete withdrawal, of such filopodia is accomplished by the reversal of the direction of the axial movement. The bidirectional streaming characteristic of the reticulopodial networks also occurs within the lamellipodia. In these flattened regions the streaming is clearly seen to occur exclusively in association with the intracellular fibrils. Transport of both organelles and bulk hyaline cytoplasm occurs bidirectionally along the fibrils.

Detection of melanoma seeding during surgical procedures--an RT-PCR based model.

AIM: It has long been suggested that malignant cells may be shed into the blood stream during any given surgical procedure for cancer. A number of studies have now reported the detection of occult melanoma cells in peripheral blood using a reverse transcriptase polymerase chain reaction (RT-PCR) based assay. The principal aim of these studies has been to determine a prognostic value for the test and not to evaluate the influence of intervention upon results. METHODS: In this pilot study we aimed to determine whether the assay could be used as a model to detect cells that are seeded during surgery. Peripheral blood samples were obtained pre- and post-operatively on twenty patients undergoing surgery for malignant melanoma - ten with primary disease and ten undergoing regional lymphadenectomy. A further ten patients undergoing surgery for non-melanoma conditions provided controls. RESULTS: Using RT-PCR, it was possible to identify tyrosinase transcripts in the peripheral blood of one of ten patients undergoing excision of local disease and four of ten undergoing surgery for regional metastatic disease. CONCLUSION: It was concluded that this technique does enable detection of a greater percentage of RT-PCR findings post-operatively. This in turn may provide a means for optimizing or comparing surgical techniques and provides a potential guide in the use of adjuvant therapies.

First branchial cleft anomalies involving the tympanic membrane and middle ear.

First branchial cleft anomalies may involve the tympanic membrane or middle ear. A complete otologic examination must be performed in any patient with a suspected first branchial cleft anomaly. A surgeon treating such a defect must be prepared to perform both the excision of the lesion and reconstructive otologic surgery.

Threshold shift, hair cell loss, and hair bundle stiffness following exposure to 120 and 125 dB pure tones in the neonatal chick.

One-day old chicks were exposed to one of two pure tone stimuli (0.9 kHz at 120 or 125 dB SPL) for 48 h. Three major results arose from a variety of tests that assessed the structural and functional consequences of the exposure on the peripheral auditory system at either 0 days or 12 to 15 days recovery. First, brainstem response data showed that the 120 and 125 dB groups had maximum evoked potential threshold shifts of 57 and 71 dB immediately after removal from the sound. Fifteen days post-exposure, the thresholds in the 120 dB group returned to near-normal levels, while in the 125 dB group, recovery was within 19 dB of control thresholds. Second, scanning electron microscopic measurements of hair cell density within the lesion showed that at 0 days recovery, the 120 and 125 dB groups had a 30% and 59% short hair cell loss, respectively, but by 15 days no differences could be identified between the exposed and control animals, regardless of exposure level. Finally, at 0 days of recovery, micromechanical stimulation data did not reveal any significant difference in stiffness between the control and surviving hair cells in the lesion area. Although the more intense exposure induced greater structural and functional damage in the chick cochlea, the birds retained or even enhanced their ability to replace lost hair cells and had partial hearing recovery by 15 days post-exposure.

Erythromycin sclerotherapy in the management of seroma.

Post-operative seroma can present the clinician and patient with a chronic and difficult problem. The authors present their experience of managing refractory seroma with the antibiotic erythromycin, administered for its properties as a sclerosant. The technique was found, in a series of patients, to be effective, simple and without serious complications.

Assessment of nurse-led screening of pigmented lesions using SIAscope.

UNLABELLED: The incidence of malignant melanoma in the UK is rising. Increased awareness of melanoma has led to an increase in patients presenting with pigmented lesions to their general practitioner (GP) and to pigmented lesion clinics. The sensitivity and specificity of the general practitioner in diagnosing melanoma remains poor. OBJECTIVES: A trial was conducted to establish the effectiveness of SIAscope in triaging patients referred by GPs on suspicion of melanoma. MATERIALS AND METHODS: After Ethical Committee approval, all consenting patients attending the Pigmented Lesion Clinic at Frenchay Hospital were scanned with the SIAscope. The consultant then examined all the patients and all suspicious lesions were excised and examined. RESULTS: Eight hundred and eighty-six patients were included in the trial. The SIAscope had a sensitivity of 94.4% with a false negative rate of 3.7% for malignant melanoma. CONCLUSIONS: The SIAscope could be useful in reducing the number of benign lesions seen by the consultant while still identifying most melanomas.

Psychological distress surrounding diagnosis of malignant and nonmalignant skin lesions at a pigmented lesion clinic.

This study aimed prospectively to investigate psychological distress throughout the diagnostic process in an outpatient pigmented lesion clinic (PLC). Psychological distress was measured at pre clinical diagnosis, post clinical diagnosis, pre histological diagnosis (including a benign follow-up) and post histological diagnosis stages using standard anxiety measurement scales and a study specific measure of satisfaction with care. In total 324 patients undergoing investigation of a suspicious skin lesion consented to take part out of a cohort of 463 patients who attended the PLC in a 6 month period. Using recognised cut-off scores, 27% of women on clinic arrival reported clinically high levels of anxiety, in comparison with 10% of men (p < 0.0001). Patients given an immediate benign post clinical diagnosis reported a reduction in anxiety (p < 0.0001) but patients requiring a biopsy reported elevated levels of anxiety. Approximately, 30% of these biopsy patients reported clinically high levels of anxiety both before and after diagnosis. Patients who received a post histological diagnosis of malignant melanoma also reported the pre histological stage at the clinic as more distressing than waiting for and receiving results (p < 0.01). Patient's quality of life prior to diagnosis was excellent, but emotional functioning (p < 0.05), insomnia (p

The role of the Lumina intense pulsed light system in the treatment of port wine stains--a case controlled study.

The pulsed dye laser has been the treatment of choice for port wine stains over the past 20 years. In the past 5 years there has been increasing discussion of the role of other light treatments, such as the intense pulsed light system in the treatment of port wine stains. These systems use high-energy lamps, which emit noncoherent broad-spectrum light. Cut off filters are applied depending on the treatment modality to limit the wavelengths emitted. We present the results of a 3-year prospective within patient controlled clinical trial using an intense pulsed light system called the Lumina, developed by Lynton Lasers of Cheshire, England. Our aims and objectives were to assess the effectiveness of the system in the treatment of port wine stains in a human model and to record the optimum treatment parameters and the incidence of side effects. Following ethical approval 12 subjects were enrolled into the trial. In order to meet the requirements of the local ethics committee these were all adults with port wine stains located in less visible areas of the body. The results showed that eight of the 12 subjects had some degree of fading of their port wine stain as measured on a percentage scoring system. Of the four who failed to show any response, all had pink port wine stains. It did seem the case that the darker the port wine stain, the better the fading seen. Furthermore, the more distal lesions tended to be less responsive than those situated closer to the head area. However, it is difficult to draw any definitive statistical conclusions due to the small number of patients in the trial.

Aluminum in parenteral products: LVP and SVP, FDA medical perspective.

Relatively little is known concerning Al toxicity in man or animals. Current literature associates encephalopathy, osteodystrophy, and anemia with excessive Al accumulation. The normal gastrointestinal tract is probably an efficient barrier to absorption and the normal kidney appears to eliminate Al efficiently. When administered parenterally, the g.i. barrier is by-passed. In the presence of renal failure, accumulation may occur. "Toxic" levels of Al have not been clearly established to guide clinicians, nor have "safe" levels in parenterals been defined. The extent of intoxication as a clinical problem is unknown, but may be more common in selected patient groups than is recognized. In the absence of reliable data, specific regulatory action has not been taken. In the interest of public health, the FDA is attempting to accumulate information for guidance of parenteral drug manufacturers and clinical practitioners.

Use of a carbon dioxide laser in the treatment of multiple epidermoid cysts.

We treated a 41-year-old woman for multiple epidermoid cysts to the face using a carbon dioxide laser. The management and its rationale are discussed.

The use of nerve blocks in the laser treatment of cutaneous lesions.

Lasers are now well accepted as standard treatment for many cutaneous lesions. Many types of laser treatment require pain relief, the choices being general anaesthesia, (particularly in younger patients), or local or topical anaesthesia (EMLA). There have been few reports on the specific use of local anaesthetic nerve blocks in the laser treatment of cutaneous lesions. We present our experience of 816 nerve blocks in 135 patients (53 males, 82 females; age range 5-73 years, median 27 years) during 877 treatment sessions 96% of the nerve blocks provided complete anaesthesia in the required anatomical area. Only 9 (7%) patients (1.1% of the 816 nerve blocks) developed complications that could be attributed to the anaesthetic blockade. We recommend nerve blocks as a safe and efficacious method of anaesthesia during the laser treatment of cutaneous lesions.

Laser transmission through membranes using the Q-switched Nd:YAG laser.

BACKGROUND AND OBJECTIVE: Many laser centres utilise various transparent membranes during treatment sessions with Q-switched lasers to prevent or reduce tissue splatter, thereby reducing the aerosolised biohazard of cellular debris to operator and laser. STUDY DESIGN/MATERIALS AND METHODS: We performed a series of experiments with the Q-Switched Nd:YAG laser, a selection of 11 varieties of membrane and a power meter in order to ascertain which of the membranes was the most effective protector concerning transmission of laser energy. Other mechanical properties such as transparency, strength, ease of application, and flexibility were taken into account. RESULTS: Tegaderm (overall average 94% transmission), Cling Film (93%), Bioclusive (89%), Opsite (91%), and Microwave Cling Film (87%) all consistently performed well in pure transmission terms, whereas other membranes tested such as Acetate (74%), Grades of Melinex (75%, 72%, 75%), 2nd Skin (74%), and Perspex (68%) were unsuitable as protection. CONCLUSION: Cling Film proved to be the best all round membrane. We recommend its use for operator and laser protection against the tissue spatter produced from the Q-Switched Nd:YAG laser.

Follow-up requirements for thick cutaneous melanoma.

The primary aim of postoperative melanoma follow-up is the early detection and treatment of treatable recurrences which gives a survival advantage to these patients. The need for follow-up is universally accepted. However, there is ongoing controversy about the duration of follow-up and frequency of reviews. We present a retrospective review of 244 patients with localised thick (> or = 4.0 mm) cutaneous melanoma, who had completed a 10-year follow-up or had died form their melanoma within 10 years. For these criteria, this is the largest series of this type which has been reported to date. The incidence of treatable recurrences peaked in the first postoperative year at 40% and then rapidly decreased, levelling off after year 5 at 2.5% per annum. We believe that this high incidence of treatable recurrences reinforces the need for 10-year follow-up of these patients. We also recommend that the annual frequency of follow-up reviews in each year be based on that year's risk for getting a treatable recurrence. Following this principle, we provide an example of such a follow-up programme.

Colour shift following tattoo removal with Q-switched Nd-YAG laser (1064/532).

Colour shift in tattoo pigment is a recognised complication of laser tattoo treatment. We report our experience over the past 4 years in treating 275 patients, with a total of 323 professional tattoos. Of these, 184 tattoos contained a pigment other than black with 33 displaying a colour shift as a consequence of laser treatment. This adverse effect was recorded with red, yellow, crimson and brown pigments but most frequently with white/flesh pigments. We found brown and white/flesh coloured pigments to be significantly more likely to change colour compared to red and that the chance of certain colours shifting related to the age of the tattoo. We outline our management of this problem and discuss the results of continued treatment.

Branchial cleft anomalies: a five-year retrospective review.

Branchial cleft cysts, sinuses and fistulas are among the most commonly encountered congenital anomalies in pediatric otolaryngic practice. They can present difficulties in differential diagnosis and surgical management. In order to study the clinical presentation and surgical management of branchial cleft anomalies, the operative records of the Children's Hospital of Philadelphia (CHOP) were reviewed for a five year period, January 1, 1982 through December 31, 1986. All patients with a pathologically-confirmed post-operative diagnosis of a branchial cleft anomaly were included in a retrospective chart review. Their case histories were studied to determine symptoms upon presentation, presence or absence of drainage, type of lesion, site of lesion, characteristics of the lesion, accuracy of pre-operative diagnosis, recurrence and complications. A total of 71 patients, 39 males and 32 females, underwent surgical excision of a branchial cleft cyst, sinus or fistula during the study period. There were 23 branchial cleft cysts, 50 sinuses and 3 fistulas. A correct pre-operative diagnosis was established in 60 (85%) of the patients, being highest for patients with branchial cleft fistulas. Incorrect pre-operative diagnoses included thyroglossal duct cyst, cervical lymphadenitis, dermoid, dermal inclusion cyst, lymphangioma and malignant neoplasm. The clinical presentation, pre-operative evaluation, pitfalls in diagnosis, surgical management and post-operative complications are discussed and strategies for the management of branchial cleft anomalies are presented.

The detection of tyrosinase mRNA in peripheral blood samples is unlikely to aid in the management of patients with localised malignant melanoma.

A number of authors have reported the detection of tyrosinase mRNA in the peripheral blood of patients with malignant melanoma using the reverse transcription polymerase chain reaction (RT-PCR). The precise value of this assay as a prognostic tool, however, remains in doubt. This is particularly so with relation to localised disease, where relatively little data has been accumulated. In this study we analysed the peripheral blood of 50 consecutive patients with primary malignant melanoma referred to a plastic surgical centre with the facility of a pigmented lesion clinic. Samples were analysed from an additional 35 patients with advanced melanoma disease and 35 patients with benign pigmented cutaneous lesions. We were able to identify tyrosinase transcripts in the peripheral blood of only two of 50 patients with localised disease. Of those with more advanced disease, a positive finding was found in three with regional disease and four patients with metastatic spread. Stage of disease was found to correlate significantly with PCR status. No correlation was identified with other prognostic markers or with outcome over a three-year period. This data would support the conclusion that the detection of tyrosinase mRNA in peripheral blood is likely to be of little value as an aid in the management of patients with early malignant melanoma.

A 6 year prospective analysis of the diagnosis of malignant melanoma in a pigmented-lesion clinic: even the experts miss malignant melanomas, but not often.

We investigated whether the pigmented-lesion clinic (PLC) run by the Department of Plastic and Reconstructive Surgery at Frenchay Hospital was effective in making and excluding the diagnosis of malignant melanoma, by looking at the pattern of referrals over time, the number of melanomas excised and melanomas in which the diagnosis was delayed or missed. We also investigated whether the PLC was having an effect on the thicknesses of melanomas excised. All 9968 patients attending the PLC between 1 January 1993 and 31 December 1998 were included in the study and 586 malignant melanomas were diagnosed; 24.7% of excisions led to the diagnosis of malignant melanoma. Seven invasive melanomas and two lentigo malignas were missed. There was one histological false negative. The PLC has a sensitivity of 98.5% and specificity of 89.2% for the diagnosis of melanoma; the negative predictive value is 99.9%. The PLC is effective in rapidly making or excluding the diagnosis of malignant melanoma, but has had no effect on the average thickness of melanomas excised over the 6 year study period.

Sub-lethal effects of exposing the human melanoma cell line SKmel-23 to 532 nm laser light.

The human melanoma cell line SKmel-23 has been used to investigate the sub-lethal damage that can occur as a result of exposing melanin containing cells to light (532 nm) from a frequency doubled Q-switched (Nd:YAG) laser. A dose response curve was obtained, which indicates that at energy levels of 0.6 J/cm2 and below no effect on either the viability or growth rate of the cell line was observed. Above this, cells rapidly died and at an energy level of 2.0 J/cm2, only approximately 15% of cells survived. This contrasts with the effects on the G361 melanoma line, which contains far less melanosomes, as an LD50 for this cell line was approximately 5.5 J/cm2. Exposing SKmel-23 cells to 0.4 J/cm2 of 532 nm light results in a diminution of the number of melanosomes within cells as well as a marked decrease in melanin content, as determined by spectrophotometric assay and electron microscopy. Using the reverse transcriptase polymerase chain reaction technique, the reduction in melanin content of the cells was accompanied by a selective decrease in mRNA coding for tyrosinase, the first enzyme in the biosynthetic pathway for melanin. No decrease in the mRNA coding for the GAPDH protein was observed. Our finding has implications for understanding the control processes that regulate the melanin content of cells and suggests that the model described can be used to further investigate changes that may occur in cells as a result of their exposure to sub-lethal levels of laser light.