Relation between tissue structure and imposed electrical current flow in cervical neoplasia

BACKGROUND

When an electrical potential is applied to human tissue, the pattern of the resulting current flow is determined by the shapes, arrangements, and internal structure of the tissue cells. By measurement of the electrical current patterns over a range of frequencies, and use of an inverse modelling procedure, electrical variables describing the tissue structure can be calculated. We used this method to develop a screening technique for the detection of cervical precancers.

METHODS

We used a pencil probe (diameter 5 mm) to measure electrical impedance spectra from eight points on the cervix in 124 women with abnormal cervical smears. Variables that should be sensitive to the expected tissue changes were calculated. These were compared with the colposcopic results.

FINDINGS

The measured electrical impedance changes were those predicted on the basis of the expected tissue structures. Measurements made on normal squamous tissues were well separated from those made on precancerous tissues. We constructed receiver-operating-characteristic curves, comparing measurements made on normal tissue and that showing cervical intraepithelial neoplasia grade 2/3; the area under the curve was 0.951. These groups of women could be separated with a sensitivity of 0.92 and a specificity of 0.92.

INTERPRETATION

Characteristics of the electrical impedance spectra of tissues can be explained by changes in cell arrangements (layering) and in the size of the nuclei. This relation opens the way to deriving tissue structure from electrical impedance spectral measurements. We show that this approach can be used to give good separation of normal and precancerous cervical tissues.

Outcome after surgical resection for high-grade anal intraepithelial neoplasia (Bowen's disease)

BACKGROUND

High-grade anal intraepithelial neoplasia (Bowen's disease) may predispose to anal carcinoma. Treatment options include surgical resection but effectiveness remains uncertain. This paper reports long-term follow-up of patients with high-grade anal intraepithelial neoplasia treated by surgical resection.

METHODS

Between 1989 and 1996, 46 patients were identified with high-grade anal intraepithelial neoplasia. Thirty-four underwent local excision of all macroscopically abnormal disease and the resulting defect was left open, closed primarily or skin grafted. Regular follow-up subsequently included anoscopy and biopsy of any suspicious lesions.

RESULTS

Median follow-up was 41 (range 12-104) months. Total excision was difficult; 19 patients had histological evidence of incomplete excision at the time of initial resection. Some 12 of 19 had histo-logically proven recurrent high-grade intraepithelial neoplasia within 1 year. Even with microscopically complete excision two of 15 patients subsequently developed recurrent high-grade intraepithelial neoplasia at 6 and 32 months after operation. No patient developed carcinoma but five had complica-tions of anal stenosis or faecal incontinence.

CONCLUSION

Although no definite recommendations can be made for the treatment of high-grade anal intraepithelial neoplasia, these results illustrate some potential drawbacks of surgical excision with a high potential for incomplete excision and persistent disease, even after complete excision in some patients, and a high morbidity rate.

The significance of Erb-b2 immunostaining in cervical cancer

OBJECTIVE

The aim of this study was to assess the relationship between survival and erb-b2 immunohistochemical staining in patients with early stage cervical carcinoma.

METHODS

Archival specimens for 126 patients with stage IB/IIA cervical carcinoma treated with radical hysterectomy and bilateral pelvic node dissection (RH-BPND) were retrieved and submitted to immunohistochemistry for ERBB2 expression. The association between positive results and poor survival was assessed in a multivariate analysis.

RESULTS

Erb-b2 immunostaining was significantly associated with poor survival (P = 0.0284) but less so than parametrial extension (P = 0.0014) and nodal disease (P = 0.0106). Tumor type (squamous/adenosquamous/adenocarcinoma) and the status of surgical margins were not significantly associated with survival.

CONCLUSIONS

These results supported further investigations of ERBB2 expression as a marker of high-risk disease in patients treated with RH-BPND.

Skin appendage involvement in anal intraepithelial neoplasia

BACKGROUND

High-grade anal intraepithelial neoplasia (AIN III) may be premalignant. Surgical excision of large areas of anal epithelium carries significant morbidity. Ablation treatments may carry less morbidity; however, the depth of ablation is uncertain and failure to ablate dysplasia in hair shafts and other skin appendages may lead to early recurrence.

METHODS

This study assesses morphometric aspects of skin appendages in perianal skin and anal canal mucosa in tissues from 30 patients with AIN III. Both normal and dysplastic epithelium was assessed in each patient. The depth to which AIN III involved skin appendages was measured using computerized image analysis.

RESULTS

Both the perianal epidermis and anal canal mucosa affected by AIN III were significantly thicker than normal. Nineteen of 30 patients with AIN III had skin appendage involvement. Some 57 per cent of hair follicles (79 of 138), 16 per cent of sebaceous glands (11 of 69) and 25 per cent of sweat glands (24 of 96) observed beneath an abnormal epithelium had evidence of AIN. The median depth of AIN involvement of the hair follicle was 1.14 (range 0.44-1.67) mm, sebaceous glands 1.44 (range 0.96-1.90) mm, and sweat glands 0.94 (range 0.50-2.20) mm. These figures do not take into account tissue shrinkage due to histological processing.

CONCLUSION

AIN III involvement of epithelial appendages is a significant problem. For disease eradication, tissue destruction or removal to a depth of at least 2.2 mm below the adjacent basement membrane is required. Surgical excision of high-grade AIN remains the treatment of choice.

Conclusions and recommendations from the Helene Harris Memorial Trust Fifth Biennial International Forum on Ovarian Cancer, May 4-7, 1995, Glasgow, UK

The Fifth Biennial International Forum on Ovarian Cancer was held by the Helene Harris Memorial Trust in Glasgow, UK. The main points of the presentations given by the invited speakers, together with the fruits of extensive discussions are presented here as a series of conclusions and recommendations which should be given consideration by all those having an interest in researching or treating ovarian cancer. The individual points are grouped into topics considering whether there is an identifiable ovarian pro-cancer, whether ovarian cancer is preventable, advances in familial ovarian cancer, its molecular genetics, ways of optimizing treatment, obstacles to successful treatment and approaches to gene therapy.

Positron emission tomography: 2-deoxy-2-[18F]-fluoro-D-glucose uptake in locally advanced breast cancers

Fifteen patients with locally advanced breast cancers were studied using the radiopharmaceutical 2-deoxy-2-[18F]-fluoro-D-glucose (FDG) with positron emission tomography (PET). Five patients were sequentially imaged before and after two pulses of chemotherapy. In 14 of 15 tumours increased uptake of FDG was observed which correlated with the clinical site of the tumour. The PET images were compared with the mammographic and ultrasonomammographic appearances of the tumours in selected patients. In two patients with normal mammograms PET imaging detected the tumour and in a further four patients, with suspicious but not conclusively malignant mammographic changes, a well-defined area of increased FDG uptake was demonstrated by PET. In all five sequentially imaged tumours, following chemotherapy, there was a decrease of the FDG tumour: normal breast uptake ratio. In four patients who completed a full chemotherapeutic course this change preceded a pathological response of their tumours. These findings suggest that this technique may be of benefit in imaging carcinomas in the breasts of pre-menopausal women which may appear dense on mammography and moreover, that sequential imaging may have a role in the prediction, at an early stage, of the response of locally advanced carcinomas to chemotherapy.

Treatment of anal intraepithelial neoplasia

The natural history and malignant potential of anal intraepithelial neoplasia (AIN) remain uncertain, making management decisions about such lesions difficult. The management of 70 patients with AIN is described. The majority of lesions encountered were low grade (AIN I and II; 43 of 70) and required no treatment, but eight invasive anal cancers associated with high-grade AIN occurred over the 4-year study period. Three were a result of apparent progression of high-grade lesions; three more invasive lesions were found in areas of AIN III on histological examination. Surgical excision was used to treat 27 patients with AIN III. Treatment of extensive lesions involving the perianal and anal canal epithelium circumferentially in six patients involved excision of the whole of this epithelium and application of split skin grafts.

Necrotising granulomas of the uterine corpus

Images

Conclusions and recommendations from the Helene Harris Memorial Trust Fourth Biennial International Forum on Ovarian Cancer 11-14 May 1993, Toronto, Canada

The Helene Harris Memorial Trust organizes biennial international meetings of leading clinicians and scientists to discuss progress in the understanding and treatment of ovarian cancer. The conclusions of this meeting, together with recommendations for future research are published as a guide to others working in this field. The 107 conclusions and recommendations presented cover the full range of current topics in ovarian cancer research including the biology of early and borderline tumors, the relationship of benign to malignant tumors, in vitro models, the role of cytokines, genetic epidemiology, oncogenes and tumor suppressor genes, allele loss, localization of the BRCA1 gene, DNA ploidy in prognosis, the therapeutic use of interferon, platinum and taxoid drugs, screening with panels of tumor antigensm immunotherapy and potenial for gene therapy.

Anal colposcopy and the diagnosis of anal intraepithelial neoplasia in high-risk gynecologic patients

The objective of this study was to define the colposcopic features of the normal anal canal and of anal human papillomavirus (HPV)-associated lesions, including anal intraepithelial neoplasia (AIN), and to correlate the colposcopic impression with the final histopathologic diagnosis. A controled colposcopic screening study of women considered at risk for HPV-associated anal epithelial abnormalities was carried out. All colposcopic assessments included a biopsy with matching histopathologic diagnosis. The study group consisted of 213 women who were considered at risk of anal HPV infection and AIN. A further group of 50 women, who had no previous history of ano-genital HPV infection or AIN and whose recent cervical smear was negative were recruited as controls. Informed consent was obtained from all patients, and the study was approved by the local ethical committee. In the control group of 50 women no AIN was detected. Normal histology was obtained in 45/50 (90%) biopsies where normality had been predicted on colposcopy. Histologic diagnosis in the at-risk group was normal in 143 (67%), subclinical papillomarvirus infection (SPI) in 24 (11%), and AIN of all grades (including three cases of early invasive squamous cancer in a field change of AIN III) in 46 (22%) patients. Nineteen of 24 (79%) cases of SPI were incorrectly predicted as normal on colposcopy, and another one (4%) as AIN I-II. Only four (17%) cases of SPI were correctly predicted at colposcopy. Of the 46 cases of histologically proven AIN, 26 (56%) were AIN I-II, and 20 (44%) were AIN III. Some 50% of AIN I-II were incorrectly predicted as SPI on colposcopy. Of the 20 AIN III lesions, 15 (75%) were correctly predicted by colposcopy. Three (20%) of these lesions contained foci of early invasion, of which in only one case (33.3%) was invasive disease suspected at colposcopy. Some 25% (5/20) of AIN III lesions were incorrectly diagnosed as AIN I-II at colposcopy. As is the experience with colposcopic assessment of the cervix, anal colposcopy predictions correlated well with the final histologic diagnosis, at the normal and high-grade AIN ends of the spectrum. The colposcopic predictive distinction between SPI and low-grade AIN (I-II) was less accurate. It was difficult to distinguish early invasive lesions within a field change of AIN III, from pure AIN III. In these studies there were three cases of early anal squamous carcinoma arising in AIN III lesions, two of which were unsuspected clinically.

Prevalence of anal human papillomavirus infection and intraepithelial neoplasia in renal allograft recipients

A study was performed to test the hypothesis that renal allograft recipients are at high risk of developing anal human papillomavirus (HPV) infection and anal intraepithelial neoplasia (AIN). A total of 133 renal allograft recipients and 145 control patients underwent anoscopy and biopsy. A polymerase chain reaction was used to detect HPV16 DNA in biopsy samples. A histological diagnosis of anal HPV infection or AIN was made in 32 allograft recipients (HPV infection, five; AIN I, 20; AIN II, three; AIN III, three; AIN III and anal cancer, one). One subject with AIN was detected in the control group. HPV16 DNA was detected in 47 and 12.4 per cent of anal biopsies in the allograft and control groups respectively. Renal allograft recipients are at high risk of developing anal HPV infection and neoplasia (P < 0.05). Further studies are required to determine whether screening anal examination is required in organ allograft recipients.

Drugs acting at the strychnine-insensitive glycine receptor do not induce HSP-70 protein in the cingulate cortex

The potential for compounds acting at the strychnine-insensitive glycine receptor to injure neurons was examined using induction of a 70 kDa heat shock protein (HSP-70) as a marker. HSP-70 was consistently detected in retrosplenial and cingulate cortices after MK-801 but not glycine drug treatment. Elsewhere in the cortex, mild diffuse HSP-70 immunoreactivity was detected following 7-chlorokynurenic acid. Following HA-966, intense hippocampal HSP-70 immunoreactivity was observed. These findings indicate that even after very high doses, drugs acting at the strychnine-insensitive glycine receptor are less likely to injure cingulate cortical neurons than other classes of NMDA antagonists.

Anal human papillomavirus infection and squamous neoplasia in patients with invasive vulvar cancer

OBJECTIVE

To test the hypothesis that women with invasive vulvar cancer are at high risk of developing human papillomavirus (HPV)-associated anal squamous neoplasia.

METHODS

Forty women (median age 54.5 years; range 25-86) who were being treated or had been treated for invasive vulvar cancer and who had not had radiotherapy to the pelvis or anogenital region underwent anal microendoscopy and biopsy. A second group of 80 women who were similar in age to the study group and had no history of anogenital HPV infection or neoplasia formed the control group. The polymerase chain reaction was used to detect HPV 16 DNA in the vulvar and anal tissue samples from 33 patients in the study group and in the anal biopsies of all controls.

RESULTS

A histologic diagnosis of anal HPV infection or squamous neoplasia was made in 19 of 40 biopsies (47.5%) in the study group. These diagnoses consisted of one HPV, two anal squamous intraepithelial lesions (SIL) grade I, 15 and SIL grade III (four of which were associated with invasive anal cancers), and one invasive cancer in the absence of anal SIL. Human papillomavirus 16 DNA was detected in 16 of 33 (48.5%) of anal and 25 of 33 (75%) of vulvar biopsies. In addition, HPV 16 was detected in both the anal and vulvar samples in 13 of 16 cases (81%) of anal SIL III and invasive anal squamous cancer. No evidence of anal SIL was found in the controls, and HPV 16 DNA was identified in only 11 (13.7%) of the anal biopsies in this group.

CONCLUSIONS

This study provides further evidence for the etiologic relation between genital and anal squamous neoplasia. Furthermore, it shows that women with vulvar cancer are at high risk of having or developing HPV-associated anal neoplasia, particularly in younger patients (P = .0006; 95% confidence interval 12-34). Routine anal examination should be performed in patients with invasive vulvar cancer.

Immunohistochemical analysis of p53 expression in anal squamous neoplasia

AIMS

To determine the pattern of expression of the p53 tumour suppressor gene product in anal squamous neoplasia, and to determine if this could be used as a marker of disease progression. The association between p53 expression and human papillomavirus (HPV) 16 DNA status of the anal lesions was also investigated.

METHODS

The presence and localisation of the p53 protein in formalin fixed, paraffin wax embedded specimens of anal squamous epithelium (normal and neoplastic) was examined using immunohistochemical staining with a panel of two monoclonal antibodies (DO-1, DO-7) and one polyclonal antibody (CM-1). Thirty nine normal anal epithelia, 14 anal intraepithelial neoplasia (AIN) grade 1, seven AIN 2, and 20 AIN 3 specimens were obtained from patients without demonstrable invasive disease; twelve AIN 3 specimens adjacent to invasive disease and 34 anal squamous cancers were also examined. Genomic DNA from all 126 specimens was extracted and analysed for HPV 16 DNA using the polymerase chain reaction (PCR).

RESULTS

Nuclear p53 was strongly expressed in 67% (23/34) of invasive anal squamous tumours, 75% (9/12) of AIN 3 specimens adjacent to invasive disease, and in 60% (12/20) of AIN 3 specimens obtained from patients without demonstrable invasive disease. Two of the patients in the latter group with positively staining specimens subsequently developed invasive tumours which had staining characteristics similar to those of the AIN 3 specimens. p53 protein was expressed in very low concentrations in low grade AIN and not at all in normal anal squamous epithelium. In those specimens which stained positively for p53, HPV 16 DNA sequences were detected in 69.5% (16/23) of invasive disease, 77.7% (7/9) of AIN 3 adjacent to invasive disease, 75% (9/12) of AIN 3 obtained from patients without demonstrable invasive disease, 33.3% (2/6) of AIN 2, and in 40% (2/5) of AIN 1. There was no significant correlation between p53 immunostaining and HPV 16 DNA status (p < 0.05).

CONCLUSIONS

Aberrant expression of the p53 gene product is probably involved in the pathogenesis of anal squamous neoplasia. Long term follow up studies of all patients with AIN are required to determine if this could be used as a marker of likely disease progression from high grade AIN to invasive disease. There does not seem to be an association between the presence or absence of HPV 16 DNA sequences and mutant p53 proteins in anal squamous neoplasia.

Artificial sapphire contact probes in Nd:YAG endometrial ablation: a quantitative in vitro and in vivo study

Artificial sapphire contact probes offer theoretical advantages in Nd:YAG endometrial ablation. To examine this, an in vitro and in vivo study of laser-tissue interaction was performed. In vitro, a linear correlation was found between applied energy and total depth of effect, that is, photovaporization and photocoagulation. Using a Round (MTR 1.5) contact probe, an applied energy of 30 joules gave a depth of myometrial effect of 3.3 mm. In vivo, there was a significant reduction in tissue effect (p less than 0.001) compared to in vitro. Difficulty of manipulation of the contact laser probe within the uterus also caused a significant reduction (p less than 0.001) in depth of tissue ablation achieved on the posterior uterine wall compared with that achievable at the uterine fundus, but this may be counteracted by increasing applied energy.

C-myc oncogene expression in anal squamous neoplasia

AIMS

To determine the pattern of c-myc oncogene expression in anal squamous neoplasia and to determine if this could be used as a marker of disease progression.

METHODS

The presence and localisation of the c-myc gene product p62 in archival specimens of anal squamous epithelium, normal and neoplastic, was examined using immunohistochemical staining with the monoclonal antibody Myc1-6E10. Ten normal and epithelia, 10 anal intraepithelial neoplasia (AIN) III, and 31 anal squamous cancers were examined.

RESULTS

There was a noticeable difference between the staining characteristics of invasive tumours, normal anal epithelium, and AIN III. Intense, diffuse, mixed nuclear and cytoplasmic (n = 14) and exclusively nuclear (n = 8) staining in 22 of 31 (71%) of invasive anal tumours was observed. All positively staining tumours were well differentiated histologically, while the negatively staining nine of 31 (29%) were poorly differentiated (n = 7) and moderately well differentiated (n = 2). In six positively staining tumour sections adjacent areas of AIN III and non-dysplastic anal epithelium had staining characteristics similar to those of the invasive component. Staining in both normal anal epithelium (4/10) and AIN III specimens obtained from patients without a history of invasive disease (8/10) was less intense, focal in distribution, and exclusively nuclear. No difference in staining characteristics could be detected in these two groups.

CONCLUSIONS

The results of this study suggest that c-myc oncogene expression is implicated in the pathogenesis of anal squamous neoplasia, and that immunohistochemical staining for c-myc protein may be helpful in identifying those AIN III lesions most likely to progress to invasive tumours.

Anal intraepithelial neoplasia: part of a multifocal disease process

Invasive carcinomas of the anogenital epithelium share a common aetiological factor--human papillomavirus (HPV) type 16. Although genital intraepithelial neoplasia may be multifocal, there have been no studies of the prevalence of anal intraepithelial neoplasia in women with intraepithelial neoplasia of the genital tract. We tested the hypothesis that women with high-grade cervical intraepithelial neoplasia are at higher risk of disease in the anus than are control women of similar age with no history of anogenital neoplasia. 29 (19%) of 152 women with cervical intraepithelial neoplasia grade III had histological evidence of anal intraepithelial neoplasia. Of the 29 patients, 11 had grade III anal lesions; 2 of those women had concomitant invasive anal squamous-cell carcinomas. Only 7% (8/115) women with high-grade lesions of the cervix alone had evidence of anal intraepithelial neoplasia; by contrast, 57% (21/37) of those with more than one focus of intraepithelial neoplasia (cervix plus vulva, vagina, or both) had anal lesions. HPV 16 DNA was identified in 18 (51%) of 35 anal biopsy samples in the study group. No evidence of anal intraepithelial neoplasia was found in the control group (50 women), although 2 patients had grade I cervical lesions. HPV 16 DNA was identified in 12 (24%) of biopsy samples from the cervix and 7 (14%) from the anus in the control group; all 7 women with anal HPV 16 had concomitant cervical infection. The role of anal examination in the assessment of women with any focus of genital intraepithelial neoplasia requires further investigation.

Nucleolar organiser regions (AgNORS) in anal intraepithelial neoplasia and invasive anal squamous cell carcinoma

AIM

To evaluate the usefulness of counting nucleolar organiser region associated proteins (AgNORs) in the management of anal squamous neoplasia.

METHOD

Using a silver staining technique for NOR associated proteins, 32 routinely processed paraffin wax embedded sections of anal epithelium were assessed. These consisted of normal anal epithelium (n = 9), anal intraepithelial neoplasia (AIN) grades I (n = 5), and III (n = 13), and invasive squamous neoplasia of the anus (n = 5).

RESULTS

The median AgNOR counts for every 100 cells are as follows: normal anal epithelium 2.15 (95% CI 1.89-3.94); AIN I 3.21 (95% CI 2.89-7.14); AIN III 4.32 (95% CI 4.00-8.10); and invasive squamous cell carcinoma of the anus 5.51 (95% CI 2.48-10.62). There were significant differences between AgNOR counts in anal cancer and normal epithelium (p < 0.05; Mann-Whitney U test)), AIN III and normal anal epithelium (p < 0.005), and AIN III and AIN I (p < 0.05). No significant differences were observed between AIN I and normal anal epithelium, anal cancer and AIN I, and anal cancer and AIN III. There was a considerable degree of overlap among the different groups.

CONCLUSIONS

Despite the strong association between AgNOR values and degree of dysplasia, the variability within pathological grade may preclude the adoption of this technique on its own as a prognostic indicator. It may, however, be useful in conjunction with other markers of neoplastic growth such as c-myc oncogene amplification or overexpression as a marker of disease progression in AIN and invasive anal squamous cell cancer.

In-vivo studies of uterine electrosurgery

OBJECTIVE

To study the effects of electrosurgery on the living human uterus.

DESIGN

Prospective observational study.

SUBJECTS

Nine women with recurrent refractory dysfunctional uterine bleeding, listed for hysterectomy.

INTERVENTION

Experimental endometrial resection on patients immediately prior to hysterectomy.

MAIN OUTCOME MEASURES

The influence of power output, duration of exposure and repetition of consecutive surgical applications on the size of the zone of thermal necrosis in uterine tissue.

RESULTS

Resection of the endometrium was associated with a narrow zone of thermal necrosis of between 0.69 and 0.76 mm which was not dependent on power output. Duration of exposure, however, was directly related to tissue necrosis (1.44 vs 1.88 mm for 1s and 5s, respectively). Coagulation by pin-point desiccation caused a zone of thermal necrosis of 3.30-3.77 mm that was independent of either power or duration of exposure to electrical energy. Thermal transmission through the uterus in situ, during electrosurgery was minimal, the maximum recorded rise in temperature from the baseline was 0.4 degrees C. The differences between the in vitro and in vivo effects of electrosurgery are highlighted and the possible reasons for these differences explored.

CONCLUSIONS

The potential for unwanted thermally-induced damage to the uterus is small.

Nd:YAG laser endometrial ablation: histological aspects of uterine healing

Laser ablation of the endometrium performed under hysteroscopic control is a novel procedure for the conservative management of menorrhagia in cases of dysfunctional uterine bleeding. The effect this has on the uterine cavity and the mechanism of reepithelialisation and endometrial regeneration have been examined by means of histological examination of endometrial biopsies and four hysterectomy specimens obtained for various indications at varying time intervals after laser endometrial ablation. During the first 3 months, fragments of necrotic and granulation tissue are found surrounded by a limited polymorph response. By 3 months, the uterine cavity appears to be completely reepithelialised. After 6 months, areas of normal-appearing endometrium may persist, but in other areas there is an attenuated cuboidal surface epithelium closely applied, to the underlying myometrium. Stromal fibrosis reminiscent of Asherman syndrome is also apparent.

Ethanol labeling: detection of early fluid absorption in endometrial resection

A study is presented of ethanol labeling of irrigation fluid in endometrial resection. The introduction of ethanol labeling and intraoperative breath ethanol analysis provided an inexpensive and potentially useful means of detecting early fluid absorption during uterine surgery. The breath ethanol analyzer used was a hand-held meter; the irrigant solution was 5% dextrose with 1% ethanol. Simultaneous breath and venous samples were taken from women undergoing endometrial resection. An increase in breath ethanol was positively correlated with fluid absorption, blood ethanol, and serum glucose. This technique may prove valuable in preventing fluid overload during endometrial resection.

Preliminary observations of holmium:YAG laser tissue interaction using human uterus

Preliminary observations of a pulsed Ho:YAG laser on human uterine tissue in-vitro are presented. The tissue effect on the uterine myometrium was demonstrated using fresh uteri which had been subjected to laser energy. The laser crater and surrounding zone of thermal necrosis (ZTN) was quantified. Measurements demonstrated a consistent narrow ZTN (0.8-1.8 mm) irrespective of power or pulse frequency used. The percentage forward transmission of laser energy through 1 mm of myometrium was investigated using a pyroelectric detector and found to be 0.41%. Finally, a visible and measureable photoacoustic component to the Ho:YAG laser was demonstrated using a water bath and needle hydrophone.

Preliminary evaluation of a new high power diode laser

A high-powered semiconductor diode laser (805 nm) has recently been developed for medical use. The laser-tissue interactions of this wavelength have been compared with Nd:YAG (1064 nm). When used in the contact mode, the extent of tissue vaporization and zones of thermal necrosis produced by these two lasers were similar. The diode laser was also an effective and haemostatic laser scalpel. This compact laser unit has potential advantages over existing Nd:YAG lasers.

Endocervical carcinoma and precursor lesions: c-myc expression and the demonstration of field changes

The monoclonal antibody Myc 1-6E10 was used in an immunocytochemical technique to examine the expression of the c-myc oncogene in normal endocervices and those with glandular intraepithelial neoplasia and invasive malignancy. Eleven of 14 normal endocervical biopsy specimens did not express the gene, while three showed nuclear, or light basal cytoplasmic localisation of the gene product, or both. All but one of 14 cases of low and high grade glandular intraepithelial neoplasia, and all 17 cases of invasive adenocarcinoma, showed a pan-cellular pattern of immunostaining. Of considerable additional interest was the demonstration of field changes in morphologically normal glandular epithelium in those biopsy specimens with concurrent cervical glandular intraepithelial neoplasia or adenocarcinoma. This was manifest as increased concentrations of myc proteins compared with normal tissues. These results further support the role of the c-myc gene in oncogenesis, and in the light of field changes, suggest possible difficulties in the clinical management of this group of patients.

In vitro studies of uterine electrosurgery

This study investigated electrosurgical techniques in vitro with emphasis on the tissue effects and heat transfer through full-thickness blocks of excised uterine tissue. Uterine morphometry was also examined. The 7-mm cutting resection loop was associated with a surrounding zone of thermal necrosis between 1.07-1.40 mm. There was no variation in this zone when power was altered, but a statistically significant increase was demonstrated with duration of exposure. A depth of destruction of 3.24-3.49 mm was possible with the desiccating coagulation technique, but fulguration achieved a depth of only 1.70-1.78 mm. A greater tissue effect was demonstrated as time intervals were increased. There was a fall-off in the measured rise in temperature with distance; at 4 mm from the active electrode, a mean rise of 4.5C was noted, whereas at 12 mm the mean temperature rise was 3.9C. There was a statistically significant increase in the mean temperature as power output in the cutting mode was increased. At 180 W, the mean rise was 2.0C but by 260 W, it was 3.9C. When the time interval was increased and the power held constant (220 W), a mean rise of 2.5C was recorded at 1 second, compared with 4.6C at 5 seconds, achieving statistical significance. Power increments in the coagulating mode did not alter the temperature profile, but increasing duration of exposure was associated with a significant rise in mean temperature (from 0.8 to 4.6C). A stepwise increase in the baseline temperature was noted with repetitive insults. The mean myometrial thickness of the anterior and posterior walls measured 1.8 and 1.9 cm, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Unsatisfactory colposcopy and the response to orally administered oestrogen: a randomized double blind placebo controlled trial

Thirty-six women with dyskaryotic cervical smears and unsatisfactory colposcopy were randomly allocated to receive either 30 micrograms ethinyl oestradiol or placebo daily by mouth for 10 days. Thirty-four women were available for review (17 women in each of the two groups), full colposcopic inspection of the transformation zone was possible in a significantly greater proportion of the oestrogen treated group (70% versus 23%, P less than 0.01). As most diagnostic conizations are currently performed on the basis of unsatisfactory colposcopy, the use of oestrogen medication followed by colposcopic reassessment should permit a reduction in the number of patients subject to operation.

Nucleolar organiser regions in adenocarcinoma in situ and invasive adenocarcinoma of the cervix

Silver binding nucleolar regions (AgNORs) were evaluated in normal endocervix, adenocarcinoma, and its potential precursor, adenocarcinoma in situ (AIS), in an attempt to increase an understanding of the natural history of cervical adenocarcinoma and to identify a marker for abnormal endocervical (atypical glandular) cells which could aid diagnosis and follow up of endocervical lesions. For every 50 cells the mean AgNOR counts were as follows: normal endocervical cells (n = 15) 79.8 (95% Cl 68-91); AIS (n = 20) 200.7 (95% Cl 182-219); and invasive adenocarcinoma (n = 30) 299 (271-328). There was no overlap between the groups of normal endocervical cells and invasive adenocarcinoma, but there was significant overlap between cases of invasive adenocarcinoma and carcinoma in situ. In six out of 17 cases with AIS, NOR count in adjacent morphologically normal glandular cells ("internal" controls) was increased when compared with the "external" (normal endocervical) control group. This suggests the presence of wider field changes not previously identified using routine histological methods. The findings suggest that AIS is a potential premalignant precursor of invasive adenocarcinoma, but that assessment of NORs is of no practical use in discriminating between the histological types of cervical carcinoma.

Nuclear and "cytoplasmic" estrogen and progesterone receptors in squamous cell carcinoma of the cervix

Biopsies from 131 women with squamous cell carcinoma of the cervix diagnosed between May 1983 and July 1986 were assayed for nuclear and "cytoplasmic" estrogen receptors (NER and CER). Progesterone receptors (PR) were also assayed in 45 of these tumors. About a third of the tumors contained both CER and NER. One or the other fraction contained ER in 76.9% of cases and PR in 66.6%. Although there was a trend for those women whose tumors contained CER or NER to have a better prognosis, this was not significant. There was no evidence that PR status affected the prognosis.

Microcolpohysteroscopic tailoring of cervical conization

The ideal cone biopsy should have its apex just above the transformation zone to ensure removal of all abnormal squamous and metaplastic epithelium in the endocervix, with only minimal normal glandular tissue included. The microhysteroscope has been shown to be useful in identifying the upper limit of the transformation zone within the canal, and this distance from the external os can be measured. However, this technique has not been evaluated to determine whether it can tailor cone length to this predetermined measurement. We report an observational analysis of 176 consecutive conizations in patients with colposcopically proved extension of abnormal epithelium high into the cervical canal. In 162 cases, the distance of the transformation zone from the external os could be measured with the microhysteroscope and its endocervicometer, permitting an attempt to tailor the cone length to this measurement plus a safety margin of 5 mm. There was good correlation between the intended cone length and the excised cone length, with 85% of the excised cones falling within 5 mm above or below the intended measurement. In 153 instances (94.4%), the excised cones had clear endocervical margins. Thus, tailoring of the cone length to the hysteroscopically determined measurement is feasible, thereby increasing the chances of complete excision while limiting cone size to the required minimum.

Endoscopic localization of the squamocolumnar junction before cervical cone biopsy in 284 patients

A preoperative examination of the endocervical canal was performed in 284 patients scheduled for excisional cone biopsy because of abnormal cervical cytology and unsatisfactory colposcopy. The information obtained regarding the depth of the new squamocolumnar junction (SCJ) was used to tailor the length of the cone specimen in an attempt to remove the entire transformation zone (TZ), and was associated with a low rate of incomplete disease excision. An analysis of the data generated by this study indicates that the position of the new SCJ is influenced by age, menopausal status, and the use of estrogen-containing medication.

Hemostasis and cold knife cone biopsy: a prospective randomized trial comparing a suture versus non-suture technique

Two methods of obtaining hemostasis after cold knife cone biopsy were compared in a prospective randomized trial involving 200 patients. One method relied primarily on hemostatic sutures, and the other involved the use of a styptic solution (Monsel's solution) and vaginal pack, thus avoiding the use of sutures altogether. The short- and long-term morbidity in these two groups were compared and 12-month follow-up was completed. The use of sutures did not reduce the incidence of primary hemorrhage. Secondary hemorrhage was twice as frequent in the suture group, although this trend did not quite reach statistical significance. During long-term follow-up, significantly more patients in the suture group developed menstrual symptoms, cervical stenosis, and unsatisfactory colposcopy, requiring further operative intervention as a result.

Planning colposcopy and gynaecological laser services

All district health authorities have recently introduced call and recall schemes for cervical cytology screening. Little attention has been given to the implications of these schemes for diagnostic colposcopy, and treatment services. This paper describes the steps necessary to estimate the likely increase in demand on these services.

The management of multiple pregnancy in women with a lower-segment caesarean scar. Is a repeat caesarean section really the 'safe' option?

Multiple pregnancy occurring in a patient who has previously had a lower-segment caesarean section is an unusual sequence of events. Retrospective analysis over an 11-year period in Sheffield from 1975 to 1985, revealed 25 cases, a rate of 1 in 3300 deliveries. The caesarean section rate in this group of women rose from 20% (3/15) in the first six years to 70% (7/10) in the latter years for no obvious reason. This change in management did not produce any improvement in fetal outcome but there was an increase in maternal morbidity. This analysis and a review of available literature suggest that multiple pregnancy is not in itself an indication for elective repeat caesarean section.

Mouse nerve growth factor gene: structure and expression

The organization and biologically significant sequences of the entire mouse nerve growth factor (NGF) gene have been determined. The gene spans 45 kilobases and contains several small 5' exons. Transcription of the gene results in four different mRNA species, which can be accounted for by alternative splicing and independent initiation from two promoters. These transcripts encode proteins which have divergent N termini and the NGF moiety at their C termini. The levels of the various NGF transcripts have been determined in different tissues and throughout postnatal development. We have also examined the expression of these transcripts in the brain in response to specific early sensory deprivation. The results suggest that the expression of NGF mRNA during postnatal development is regulated independently of the formation of complex neural networks.

Residual cervical intraepithelial neoplasia after laser ablation

Some patients with histologically proven residual cervical intraepithelial neoplasia after laser ablation have false negative cytology. The explanation for this is not known, but there was no evidence of buried lesions. Follow-up of all patients treated by selective ablation is necessary. Cytology alone is inadequate and careful, accurate pre- and posttherapy colposcopy is essential.

Treatment of preinvasive lesions of the cervix

The recognition and treatment of premalignant lesions affecting the uterine cervix will in most instances prevent the subsequent development of invasive cervical cancer. The various therapeutic options available to the clinician for the eradication of cervical premalignant disease are discussed.

Quantitative microcolpohysteroscopic assessment of the extent of endocervical involvement by cervical intraepithelial neoplasia

The Hamou microcolpohysteroscope was used to measure the extension of cervical intraepithelial neoplasia into the endocervical canal in patients before cone biopsy of the cervix. These measurements showed good correlation with those found on subsequent histological assessment.