The behaviors of seeking a second opinion from other health-care professionals and the utilization of complementary and alternative medicine in gynecologic cancer patients.

GOALS OF WORK: The aim of the study is to determine the predictors for seeking a second opinion and the utilization of complementary and alternative medicine (CAM) among gynecologic cancer patients. PATIENTS AND METHODS: Patients attending a gynecologic cancer clinic of a tertiary referral center were recruited over a period of 1 year. A survey was conducted for all the participants in a one-on-one basis. MAIN RESULTS: One hundred ninety-one patients were recruited. Eighty patients (41.9%) had consulted other health-care professionals (HCP) for a second opinion after they were diagnosed to have cancer and 89 (46.6%) had utilized CAM. In multivariate analysis, late-stage disease (OR=2.65, 95% CI 1.26-5.58), treatment with radiotherapy (OR=2.27, 95% CI 1.19-4.33) and tertiary education (OR=11.28, 95% CI 3.06-41.54) were independent predictors for seeking a second opinion from other HCP and utilization of CAM. Patients who sought a second opinion from other HCP were more likely to utilize CAM (OR=6.12, 95% CI 3.24-11.54). Eighty percent of the patients did not inform their usual caregiver their utilization of CAM. CONCLUSIONS: Seeking a second opinion from other HCP is common in gynecologic cancer patients. Patients who seek a second opinion are more likely to utilize CAM.

Expressions of c-erbB-2, epidermal growth factor receptor and pan-ras proto-oncogenes in adenocarcinoma of the cervix: correlation with clinical prognosis.

The expressions of c-erbB-2, epidermal growth factor receptor (EGFR) and pan-ras in normal cervical glands (n=45), glandular dysplasia/adenocarcinoma in situ (GIN/ACIS) (n=32) and invasive cervical adenocarcinoma (n=78) were determined and correlated with clinical prognosis. The expressions of c-erbB-2, EGFR and pan-ras in GIN/ACIS lesions and invasive tumours were significantly higher than in normal glands (p<0.001), whereas there was no significant difference between expressions in GIN/ACIS lesions and invasive tumours, except for EGFR (p=0.016). Significantly more normal glands adjacent to adenocarcinoma showed moderate/strong expressions for EGFR than c-erbB-2 (p=0.007) whereas significantly more GIN/ACIS lesions showed moderate/strong expressions for c-erbB-2 than EGFR (p=0.008). No correlation was found between moderate/strong expressions for c-erbB-2, EGFR or pan-ras and stage at presentation (p=0.384, 0.056, 0.842 respectively) or with survival (p=0.58, 0.19, 0.26 respectively). In conclusion, EGFR is more important in inducing dysplastic change/malignant transformation whereas c-erbB-2 plays a more significant role in tumour progression and invasion. However, neither c-erbB-2, EGFR nor pan-ras carried any prognostic significance on patient survival.

Anti-apoptotic proteins, apoptotic and proliferative parameters and their prognostic significance in cervical carcinoma.

The inhibitor of apoptosis proteins (IAP) suppress apoptosis induced by a variety of stimuli. The aims of this study were to: (a) compare the expression of X-linked IAP (Xiap) and Human IAP-2 (Hiap-2) in cervical carcinoma cells and normal cervix, (b) determine the correlation between IAP expression and tumour apoptosis or proliferation, and (c) assess their prognostic significance in cervical carcinomas. Paraffin-embedded tissue sections were retrieved from 77 patients with cervical squamous carcinomas prior to treatments and 47 normal subjects. Tumour apoptosis was determined by terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuracil triphosphate (dUTP) nick-end labelling (TUNEL) and apoptotic index (AI), and the proliferative rate was measured by Ki-67 and mitotic (MI) indices. Immunoreactive Xiap and Hiap-2 were found in both cervical cancer cells and normal tissues. IAP expressions in cancers did not correlate with apoptotic and proliferative parameters, disease stage and patient survival. The lower AI and Ki-67 index were associated with a better survival. In conclusion, the basal expression levels of IAPs have no prognostic significance, but AI and Ki-67 expression are potential prognostic indicators in cervical carcinoma.

Abnormal expression of pan-ras, c-myc and tp53 in squamous cell carcinoma of cervix: correlation with HPV and prognosis.

The aim of this study is to assess, in squamous cell carcinoma of the cervix, the expression of pan-ras, c-myc and tp53 at protein level using an immunohistochemical (IHC) staining method. One hundred and seven patients with squamous cell carcinoma of the cervix were recruited. Fifty-four patients were of stage 1B/2A and 53 were of stage 2B and above. Positive IHC stainings of pan-ras, c-myc and tp53 proteins were detected in 80.4%, 32.7% and 25.2% of cases, respectively. No significant correlation between overexpression of pan-ras and c-myc was detected. However, significantly higher percentages of overexpression of c-myc was found in association with overly expressed tp53 samples (p = 0.014). Human papillomavirus (HPV) was detected in 77.6% of cancers. HPV 16/18 was detected in 72% of cancers. Overexpression of pan-ras and c-myc had no correlation with HPV detection and stage. However, higher percentages of overexpression of tp53 were found in early stage disease (p = 0.017) and in HPV 16/18 positive tumors (p = 0.006). Overexpression of pan-ras, c-myc and tp53 alone or in more than one oncogenes had no prognostic significance on survival.

Abnormal expression of epidermal growth factor receptor and c-erbB2 in squamous cell carcinoma of the cervix: correlation with human papillomavirus and prognosis.

The aim of this study is to assess the expression of epidermal growth factor receptor (EGFR) and c-erbB2 and their correlation with human papillomavirus (HPV) status and prognosis in squamous cell carcinoma of the cervix. The expression of EGFR and c-erbB2 was studied at the protein level using the immunohistochemical (IHC) staining method, at the RNA level using the ribonuclease protection assay and at the DNA level using Southern blot and hybridization method. One hundred and one patients with squamous cell carcinoma of the cervix were recruited. Fifty-one patients were of stage 1B/2A and 50 patients were of stage 2B and above. Positive IHC stainings of EGFR and c-erbB2 proteins were found in 74.2 and 19.8% of cases, respectively. DNA amplifications of EGFR and c-erbB2 genes were detected in 35.4 and 17.2%, respectively. Of the patients showing positive EGFR and c-erbB2 staining, only 39.2 and 25%, respectively, showed DNA amplifications. RNA overexpression of EGFR or c-erbB2 was only detected in 2% of cervical cancers and was associated with positive staining and DNA amplifications. HPV was detected in 79.2% of the cases by HPV consensus primers L1, in 57.4% for HPV 16 and 27.7% for HPV 18. The abnormal expression of EGFR and c-erbB2 had no correlation with HPV detection and had no prognostic significance on survival.

Methotrexate infusion in low-risk gestational trophoblastic disease.

OBJECTIVES: The current study attempts to evaluate the effectiveness of methotrexate infusion therapy in the management of low-risk gestational trophoblastic disease and to find out whether an increase in the dose intensity can effect a faster remission and a shorter treatment duration. STUDY DESIGN: This is a prospective study. Between June 1990 and August 1998, 59 patients with low-risk trophoblastic disease were treated with methotrexate at a dose of 100 mg/m(2) as an intravenous bolus over 30 minutes followed by a 12-hour infusion of methotrexate at a dose of 200 mg/m(2). Folinic acid was not given unless the serum methotrexate reached a toxic level 24 hours after infusion (toxic level, 10 micromol/L). Actinomycin D was added in patients with a partial response. The follow-up period of these patients ranged from 12 to 113 months, with a median of 58.5 months and a mean of 55.7 months. RESULTS: Fifty-four patients attained a complete biochemical remission. Twenty-eight patients went into biochemical remission after one methotrexate infusion. Five patients showed a partial biochemical response. A relapse developed in 2 of the 54 complete responders at 3 months and 18 months after the initial therapy. Both patients received combination therapy consisting of methotrexate, etoposide, and bleomycin. They went into biochemical remission and have remained disease-free at the time of analysis. All of the 59 patients were in biochemical remission at the time of analysis. No significant side effects were observed except that Stevens-Johnson syndrome developed in 1 patient. CONCLUSIONS: Methotrexate infusion therapy described in this study is effective in the treatment of low-risk gestational trophoblastic disease. The omission of consolidation therapy and folinic acid rescue decreases the cost and duration of treatment.

Homozygous arginine at codon 72 of p53 has no prognostic significance in cervical cancer.

Mutation of p53, a tumour suppressor gene, is uncommon in cervical cancer but the detection of human papillomavirus (HPV) DNA in cervical cancer is common. The findings of increased susceptibility to degradation of p53 by E6 protein of HPV16/18 in cervical cancer with homozygous arginine at codon 72 (HA72) of p53 led to this study on whether cervical cancers with HA72 were more aggressive with the increase in the rate of loss of p53 function. In 102 cervical cancers, 76.5% were HPV16/18 positive and 30% had HA72. No survival difference was detected between HA72 and non-HA72 tumours irrespective of HPV16/18 status. Furthermore, the detection of HPV16/18 in cervical cancer was found not to be of prognostic significance in this study.

Clinical applicability of the ATP cell viability assay as a predictor of chemoresponse in platinum-resistant epithelial ovarian cancer using nonsurgical tumor cell samples.

OBJECTIVES: There is no basis for choosing one chemotherapy over another in platinum-resistant epithelial ovarian cancer based on published response rates. This study explores the feasibility and accuracy of the ATP cell viability assay (ATP-CVA) in predicting chemoresponse in these difficult situations to choose the most appropriate drug for treatment. METHODS: Predominantly nonsurgical tumor samples for histological proof of recurrence were tested against a panel of drugs for salvage chemotherapy. Clinicians were blinded to the test results. Patient responses were evaluated after a minimum of three cycles of single-agent chemotherapy and correlated with test results. RESULTS: The evaluability rate was 85% (5 of 33 contaminated). The majority (24) were obtained by abdominal paracentesis and trucut biopsy. Of the 28 successful assays, 8 were excluded from analysis because four chose not to have chemotherapy and four withdrew after fewer than three cycles because of unacceptable side effects. The overall response rate to salvage chemotherapy was 15%. The sensitivity was 100% and specificity 82%. Resistance was correctly predicted in 100% and response correctly predicted in 50%. The outcomes of 17 of 20 patients were predicted correctly, giving an accuracy of 85%. CONCLUSIONS: It is feasible to test nonsurgical tumor specimens in recurrent cancer. The ATP-CVA correctly identified a group of patients with a 50% chance of response to salvage chemotherapy. This information may be useful in the decision-making process. A prospective, randomized study will be done to confirm these results.

Chemoradiation and adjuvant chemotherapy in cervical cancer.

PURPOSE: Radiotherapy is the standard treatment for locally advanced cervical cancer, but treatment results remain disappointing, particularly for women with bulky central disease. We investigated the role of concurrent chemoradiation and adjuvant chemotherapy in a randomized trial. PATIENTS AND METHODS: Two hundred twenty patients with bulky stage I, II, and III cervical cancer were randomized to receive either standard pelvic radiotherapy or chemoradiation (epirubicin 60 mg/m(2)) followed by adjuvant chemotherapy with epirubicin 90 mg/m(2) administered at 4-week intervals for five additional cycles. RESULTS: Fifty-nine patients have relapsed, with a median follow-up duration of 77 months. Patients who received epirubicin radiation therapy showed a significantly longer disease-free (P =.03) and cumulative survival (P =.04). Patients who received radiation alone had significantly more distant metastasis than those who received chemoradiation (P =.012). There was no difference in long-term local tumor control (P =.99). CONCLUSION: Survival benefit has been demonstrated in patients treated with chemoradiation followed by adjuvant chemotherapy with epirubicin as compared with patients treated with standard pelvic radiotherapy alone.

The effect of amifostine on the in vitro cytotoxicity of chemotherapeutic agents in three epithelial ovarian carcinoma cell lines.

OBJECTIVES: Amifostine protects against a spectrum of toxicities induced by chemotherapy without affecting tumor cell kill. This is supported by clinical data and in vivo animal studies. However, there is a paucity of data on its effect on the tumor cytotoxicity of several chemotherapeutic agents used in recurrent epithelial ovarian cancer. This study compares in vitro cytotoxicity before and after addition of amifostine. METHODS: Three epithelial ovarian carcinoma cell lines (SKOV3, 420, 429) were exposed to cis-platinum, paclitaxel, doxorubicin, etoposide, 5-fluorouracil, bleomycin, 4-epidoxorubicin, 4-HC (activated cyclophosphamide), vincristine, actinomycin D, mitomycin C, and topotecan. Cells were pretreated with either 0 or 1.2 mM amifostine. Tumor cell kill after 6 days of incubation was measured using the ATP cell viability assay. Paired samples Student's t statistic was used to test the difference in mean ATP levels between drug-treated samples with and without pretreatment with amifostine. RESULTS: SKOV3 was sensitive to paclitaxel, actinomycin D, 4-epidoxorubicin, and vincristine. Cell line 420 was sensitive to paclitaxel, etoposide, and 5-fluorouracil. Cell line 429 was sensitive to paclitaxel and 5-fluorouracil. There was no significant difference in the mean ATP levels between drug-treated samples with and without pretreatment with amifostine for each of the sensitive drugs in all three cell lines. Similarly, there was no significant difference in the mean ATP levels in cis-platinum and 4-HC treated samples with and without pretreatment with amifostine. CONCLUSIONS: These results show that at the cellular level amifostine did not protect epithelial ovarian carcinoma cells against tumor cell kill.

Pathology slide review in gynecologic oncology: routine or selective?

OBJECTIVE: The aims of this study were to assess the cost/benefit ratio for interinstitution pathology consultation (IPC) and to identify the types of specimens with little or no risk of diagnostic error in order to reduce the cost. METHODS: All gynecologic oncology referrals having IPC from 1993 to 1998 were reviewed. Each case was evaluated by comparing both the original and the consulted pathology reports. A discrepancy was major if it led to treatment alteration. A minor discrepancy was defined as differences without clinical consequences. Consultation error was determined by comparison with the final diagnosis and clinical data obtained from the records. The cost per review was adjusted to 1998 dollars for all cases over the 5-year study period. Statistical data were obtained by Fisher's exact test and Pearson's correlation test. RESULTS: Five hundred sixty-nine pathology specimens from 498 patients were analyzed in this study. The major discrepancy rate was 6.5% and the minor discrepancy rate was 12.5%. Cytological specimens accounted for no major discrepancy and 13 minor discrepancies compared to 37 major and 58 minor discrepancies in histological specimens. The difference was statistically significant (P = 0.003). Consultation errors occurred in 5 cases with no alteration of clinical care. By excluding cervical and vaginal smears and cervical biopsy specimens in cases with clinically gross tumors, the cost can be reduced by 25% with no detriment to the clinical management. CONCLUSIONS: The types of specimens that do not need consultative pathology review include (1) cervical biopsy specimens in those patients with gross tumors and (2) cervical and vaginal smears.

Role of serial tumor markers in the surveillance for recurrence in endometrial cancer.

The aim of this study is to evaluate the usefulness of tumor markers in the follow-up of patients with endometrial cancer. The sera of 23 patients with elevated pretreatment CA125, CA15.3, and CA19.9 were collected at each follow-up visit and analyzed. Eleven patients had normal posttreatment levels and none of them developed recurrence. Twelve patients had one or more increased tumor markers, 7 (58.3%) of them developed recurrence. Among these seven patients, six had CA125 elevated by at least 10-fold and one had elevated CA19.9. The median lead time between elevation of tumor markers and clinical evidence of recurrence was 6 months. Hence posttreatment elevation of CA125 is a useful predictor for recurrence in patients with elevated pretreatment levels.

Nonuniform responses of transmembrane potential during electric field stimulation of single cardiac cells.

The response of cellular transmembrane potentials (V(m)) to applied electric fields is a critical factor during electrical pacing, cardioversion, and defibrillation, yet the coupling relationship of the cellular response to field intensity and polarity is not well documented. Isolated guinea pig ventricular myocytes were stained with a voltage-sensitive fluorescent dye, di-8-ANEPPS (10 microM). A green helium-neon laser was used to excite the fluorescent dye with a 15-micrometers-diameter focused spot, and subcellular V(m) were recorded optically during field stimulation directed along the long axis of the cell. The membrane response was measured at the cell end with the use of a 30-ms S1-S2 coupling interval and a 10-ms S2 pulse with strength of up to approximately 500-mV half-cell length potential (field strength x one-half the cell length). The general trends show that 1) the response of V(m) at the cell end occurs in two stages, the first being very rapid (<1 ms) and the second much slower in time scale, 2) the rapid response consists of hyperpolarization when the cell end faces the anode and depolarization when the cell end faces the cathode, 3) the rapid response varies nonlinearly with field strengths and polarity, being relatively larger for the hyperpolarizing responses, and 4) the slower, time-dependent response has a time course that varies in slope with field strength. Furthermore, the linearity of the dye response was confirmed over a voltage range of -280 to +140 mV by simultaneous measurements of optically and electrically recorded V(m). These experimental findings could not be reproduced by the updated, Luo-Rudy dynamic model but could be explained with the addition of two currents that activate outside the physiological range of voltages: a hypothetical outward current that activates strongly at positive potentials and a second current that represents electroporation of the cell membrane.

Tumour markers and their prognostic value in adenocarcinoma of the cervix.

Ninety-one patients with adenocarcinoma of the cervix had 4 tumour markers (TMs) assayed before treatment. Serum squamous cell carcinoma antigen (SCC) (n = 91) was raised in 25%; tissue polypeptide antigen (TPA) (n = 78) was raised in 35%; carcinoembryonic antigen (CEA) (n = 34) was raised in 26% and CA 125 (n = 64) was raised in 27% of these patients. In 47 of these 91 patients (52%), 1 or more of the markers were raised. The percentage of patients with raised TM increased with advancing stage. Univariate survival analysis showed that age, stage, raised TPA, raised CA 125, and raised TMs (any one or more) were of prognostic significance. When multivariate analysis was done and each TM was individually analysed, only age, stage and raised CA 125 were of prognostic significance. Rising SCC or TPA or CA 125 levels in serial estimations correlated well with the occurrence of recurrence. Thus, pretreatment estimation of SCC, TPA and CA 125 can be used to identify the patients who can subsequently be monitored by serial TM estimation.

Clinical outcome of micrometastasis in the lung in stage IA persistent gestational trophoblastic disease.

BACKGROUND: Computed tomography (CT) of the thorax can be used in the staging of persistent gestational trophoblastic disease (PGTD). However, the prognostic significance of micrometastasis in the lung detected by CT of the thorax has not been well documented. The aim of the study is to define the effect of micrometastasis on the clinical course of the disease. METHODS: Thirty-five patients who had nonmetastatic GTD underwent CT thorax examination before treatment in the Department of Obstetrics and Gynaecology, University of Hong Kong. All patients had workups which showed no evidence of metastasis and were diagnosed as FIGO stage IA. They all received methotrexate (MTX) infusion therapy. RESULTS: Three groups of patients were identified based on the thorax CT findings. Sixteen patients (45.7%) showed no evidence of micrometastasis on CT thorax. Two of them (12.5%) had poor response to MTX with unsatisfactory fall in serum hCG levels requiring change of chemotherapy to actinomycin D. Nine patients had suspicious micrometastasis and one (11.1%) of them needed change of MTX. Ten patients had micrometastasis and one (10%) of them needed change of MTX. There was only one recurrence and it was in the suspicious micrometastasis group (11.1%). There was no statistically significant difference in the rate of poor drug response or recurrence among the three groups of patients. CONCLUSIONS: Micrometastases in the lung do not affect the clinical outcome of patients with FIGO stage IA disease. CT thorax is not essential in the staging of GTD.

Conservative treatment of low grade squamous intraepithelial lesions (LSIL) of the cervix.

OBJECTIVE: To assess the accuracy of the cervical smear and colposcopy in diagnosing low grade squamous intraepithelial lesions (LSIL), and the natural history of LSIL. METHOD: The cytological, colposcopic and histological findings of 145 patients with a smear diagnosis of LSIL were compared, and the final outcome studied. RESULTS: The diagnosis of LSIL either by cytology alone or in combination with colposcopy was associated with a rate of overdiagnosis of 11.7% and 6.9%, respectively, and a rate of underdiagnosis of 31.0% and 26.2%, respectively. Spontaneous regression of lesions occurred in 81.1% of patients with proven LSIL, with regression within 24 months in 4/5 of cases. CONCLUSIONS: The degree of dysplasia shown in the cervical smear correlated poorly with histology. All patients with cervical smear showing LSIL should have colposcopy and colposcopic-directed biopsy to exclude the presence of more advanced lesions. In the absence of some serious lesions, it is then acceptable to observe the patient for 24 months before adopting definite treatment, as spontaneous regression is common.

[loop electrosurgical excision procedure: a review of our recent experience].

OBJECTIVE: To investigated whether persistence or recurrence of cervical intraepithelial neoplasis (CIN) is associated with an involved excisional margin during loop electrosurgical excision procedure (LEEP). METHODS: The records of 256 consecutive LEEP were studied. After LEEP, all patients were followed up by colposcopy and cytology at 4 to 6 month intervals for at least two years. A patient was classified as having persistent disease if SIL was seen within one year of treatment or recurrent disease if SIL was detected after one year of treatment. All relevant patient details including cytology, colposcopy findings, treatment histology, complications, recurrence or persistence of disease entered into a computer database. RESULTS: Complications occurred in 8 patients (3.1%). LEEP was successful in treating 226 patients (95.4)%. Eleven patients (4.6%) had persistent SIL. Involvement of the resection margin was a significant risk factor for persistent disease (3.1% for uninvolved margins vs 11.4% for involved margins, P < 0.05). Similarly, recurrent disease occurred in 9.1% of patients with involved resection margins vs 2.1% with uninvolved margins (P < 0.05). Eleven patients (4.3%) had microinvasive carcinoma. Only 3 were identified by colposcopy and directed biopsy. CONCLUSION: LEEP is established as a safe and efficacious method for the treatment of CIN, long term morbidity including the effect on subsequent fertility must be observed.

Vaginal vault cytology in the routine follow-up of patients treated for endometrial carcinoma: is it useful?

Routine follow-up visits and vault cytology following treatment for endometrial carcinoma generates a considerable workload and takes up valuable resources. A review is needed to evaluate the usefulness of this practice. Eighty six patients treated and follow-up from January, 1987 to July, 1994 were reviewed. The standard follow-up protocol consisted of physical assessment and vault cytology every 1 to 2 months for the first 2 years, every 3 months for the third year and every 6 months thereafter for at least 5 years. Recurrences were defined as histologically proven disease after a 3-month disease free interval. Fourteen patients (17%) developed recurrences. Two of the 14 patients (14%) had local recurrences in the pelvis. Only 3 of these recurrences were detected during routine follow-up. Vault cytology was negative in all patients with recurrences even when the recurrence occurred locally in the pelvis. Traditional surveillance protocols were ineffective in the detection of recurrences. Vault cytology was particularly ineffective. It was calculated that 1 recurrence was detected for every 606 visits. In this age of budgetary constraints, alternative follow-up protocols should be explored.

Prognostic significance of tumour markers in endometrial cancer.

Serum cancer antigen (CA) 125, CA15.3, CA19.9, carcinoembryonic antigen and tissue polypeptide antigen were analyzed in 100 normal subjects, 47 patients with benign gynaecological diseases and 97 patients with endometrial cancer. The incidence of individual elevated tumour markers (> 2SD) was 21.5-30.9% in cancer patients. Elevations of CA125 and CA15.3 were significantly associated with poor prognostic clinical factors. Univariate anaylses showed that elevated CA125, CA15.3 and CA19.9 were significantly associated with shorter survival. In multivariate analysis, CA15.3 was highly significant and had a larger hazard ratio. In conclusion, CA15.3 is a useful marker for the prognosis of patients with endometrial cancer.

Evidence for localized cell heating induced by infrared optical tweezers.

The confinement of liposomes and Chinese hamster ovary (CHO) cells by infrared (IR) optical tweezers is shown to result in sample heating and temperature increases by several degrees centigrade, as measured by a noninvasive, spatially resolved fluorescence detection technique. For micron-sized spherical liposome vesicles having bilayer membranes composed of the phospholipid 1,2-diacyl-pentadecanoyl-glycero-phosphocholine (15-OPC), a temperature rise of approximately 1.45 +/- 0.15 degrees C/100 mW is observed when the vesicles are held stationary with a 1.064 microns optical tweezers having a power density of approximately 10(7) W/cm2 and a focused spot size of approximately 0.8 micron. The increase in sample temperature is found to scale linearly with applied optical power in the 40 to 250 mW range. Under the same trapping conditions, CHO cells exhibit an average temperature rise of nearly 1.15 +/- 0.25 degrees C/100 mW. The extent of cell heating induced by infrared tweezers confinement can be described by a heat conduction model that accounts for the absorption of infrared (IR) laser radiation in the aqueous cell core and membrane regions, respectively. The observed results are relevant to the assessment of the noninvasive nature of infrared trapping beams in micromanipulation applications and cell physiological studies.