A comparison of women's, providers' and ultrasound assessments of pregnancy duration among termination of pregnancy clients in South Africa

OBJECTIVE

To compare providers' and women's estimates of duration of pregnancy with ultrasound estimates for determining medical abortion eligibility.

DESIGN

Cross-sectional study.

SETTING

Public termination of pregnancy (TOP) services in three provinces.

SAMPLE

A total of 673 women attending the above services for TOP.

METHODS

Women participating in a medical abortion feasibility study in South Africa provided estimates of pregnancy duration and date of last menstrual period (LMP). Each woman also had clinical and ultrasound exams. We compared estimates using the four methods, calculating the proportion of women in the 'caution zone' (< or = 8 weeks gestation by woman or provider estimate and > 8 weeks by ultrasound).

MAIN OUTCOME MEASURES

Mean gestational age by each method; difference between provider and LMP estimates and ultrasound estimates; and percentage of women in the 'caution zone'.

RESULTS

Women's estimates of pregnancy duration were 19 days fewer than ultrasound estimates (95% CI = -27 to 63). Mean provider- and LMP-based estimates were two (95% CI = -30 to 35) and less than one day(s) (95% CI = -46 to 51) fewer than ultrasound estimates. Comparing provider and ultrasound estimates, 15% of women were in the 'caution zone'; this fell to 12% if estimates of 9 weeks or fewer were considered acceptable.

CONCLUSIONS

Provider estimates of gestational age were sufficiently accurate for determining eligibility for medical abortion. LMP-based estimates were also accurate on average, but included more extreme differences from ultrasound estimates. Medical abortion could be provided in TOP facilities without ultrasound or with ultrasound on referral.

Opportunistic testing of medically underserved women for cervical cancer in South Africa

OBJECTIVE

To determine the yield of opportunistic Pap smears taken in an unscreened and medically underserved population in the Transkei Region of South Africa.

STUDY DESIGN

Cross-sectional study of 22,160 cervical cytology specimens from an unscreened population attending gynecologic outpatient clinics between January 1990 and December 1996.

RESULTS

The overall prevalence of atypical squamous cells of uncertain significance (ASCUS), low grade squamous intraepithelial lesions (LSIL) and high grade squamous intraepithelial lesions (HSIL) was, respectively, 34.7%, 8.3% and 2.4%. The ASCUS: SIL ratio was 3:1. The prevalence of invasive squamous cell carcinoma was 1.6%. The yield of opportunistic Pap smears was 10.7% including only LSIL and HSIL.

CONCLUSION

The pathologic process of precursor lesions of cervical cancer appears to start at an early age since > 20% of cases are diagnosed before the age of 30 years. In the absence of a national screening program, opportunistic testing of medically underserved women needs to be maintained and encouraged.

Customised gravidogram and fetal growth chart in a South African population

OBJECTIVE

To investigate whether gravidograms and fetal growth curves should be customized, i.e. tailor made for a specific ethnic group.

METHODS

A cross-sectional study of 800 pregnant Xhosa women attending antenatal care in the Eastern Cape Province (South Africa). The data measured was used to compare the correlation between the symphysis-fundus height measurement (SFHM) and the sonographic estimate of gestational age (SEGA), as well as the intra-uterine fetal growth curve with existing gravidograms and fetal growth charts.

RESULTS

There was a good correlation between the SFHM and the SEGA: r = 0.91 (P < 0.0001). The correlation between the SFHM and the sonographic estimate of fetal weight (SEFW) yielded a correlation coefficient (r) of 0.40 (P < 0.0001). The correlation between the SEFW and SEGA resulted in a r = 0.97 (P < 0.0001). The customized gravidogram and fetal growth chart followed the general trend seen in their Caucasian equivalents.

CONCLUSION

The comparison of our customized gravidogram and intra-uterine fetal growth curve with similar charts established in Caucasians does not show any significant difference.

Female breast cancer with 'clandestine' lymph node metastases

OBJECTIVE

To determine whether or not breast cancer with 'clandestine' lymph node metastases differ in any important way from breast cancer with macrometastases.

METHODS

A study of 116 female breast cancers over a period of two years, whose axillary contents were immuno-stained prospectively to detect the possible presence of clandestine metastases, that is tumour cells identifiable only after monoclonal antibody immunostaining.

RESULTS

The prevalence of 'clandestine' lymph node metastases was 14.7%. The maximum number of 'clandestine' lymph node metastases was three per axilla. In the cases with 'clandestine' metastases the infiltrating lobular carcinoma (ILC) type was more frequently seen than in the node negative cases: (p = 0.038) (RR = 2.44; OR = 4.0). There was no difference in the hormone receptor status between the cases without lymph node metastases and with lymph node metastases, 'clandestine' or macrometastases.

CONCLUSION

No significant difference was found between breast cancers with 'clandestine' or with macrometastases with regard to their clinico-pathologic features and hormone receptor status. The detection of 'clandestine' metastases is a painstaking and time-consuming procedure which, so far, has not been shown to be of clinical significance.

Prevention of post-spinal hypotension at elective cesarean section by wrapping of the lower limbs

OBJECTIVE

To investigate whether wrapping and/or elevation of the legs prevents post-spinal hypotension at cesarean section (CS).

METHODS

82 parturients in a community hospital were randomly allocated to one of 4 groups: raising, wrapping, raising and wrapping of the legs and no intervention. The outcome measures were the upper level of blockade, pulse rate and arterial systolic pressure (SAP). Statistical evaluation included paired and unpaired t-test, contingency table analysis and repeated measures analysis of variance.

RESULTS

The SAP remained significantly higher with wrapping; elevation did not add any benefit. The number of episodes of severe hypotension (defined as a SAP decrease > or = 20% of baseline and < 100 mmHg) was significantly reduced by wrapping (15.8% of cases) as compared to controls (45.5%)(chi2 = 11.02; P = 0.012). Elevation alone did not prevent hypotension (chi2 = 0.76; P = 0.38).

CONCLUSION

Wrapping of the legs at spinal block for Cs is recommended to reduce hypotension.

Ophthalmia neonatorum revisited

The microbiology, epidemiology and pathophysiology of ophthalmia neonatorum are reviewed with special emphasis on its prevention and management in the developing world. Although prophylaxis should be mandatory, no single topical agent is effective to prevent the ocular complications of both Neisseria gonorrhoea and Chlamydia trachomatis. Where levels of resistance to tetracyclines are low, however, tetracycline eye ointment is permissible for ocular prophylaxis. Eye prophylaxis has a relatively low failure rate. Management of ophthalmia neonatorum should be syndromic and systemic. Contact tracing is an integral part of the management.

Post-spinal hypotension at cesarean section: the denial of evidence

Post-spinal hypotension at cesarean section appears difficult to prevent, despite the three obligatory so-called preventative measures. So far, literature data provide no compelling evidence that expectations have been met in this regard. A critical appraisal of volume preload, ephedrine prophylaxis and left lateral supine position shows that the preventative measures should be re-evaluated. New avenues should be explored aiming at a better prevention and decrease in both the prevalence and magnitude of post-spinal hypotension at cesarean section.

A simple painless, dangerless and easily repeatable procedure for endometrium biopsy

Endometrium biopsies are currently carried out with the Novak curette. The drawbacks of this procedure are well known. The use of a female, disposable, sterile, plastic urinary catheter is a useful, easy, painless, dangerless and repeatable alternative to obtain suitable endometrium samples for histopathologic diagnosis. Since a small endometrial cancer can be overlooked, selection of patients is obligate, but this holds also insofar as all methods of endometrium biopsy are concerned. Accordingly, the procedure is primarily suitable in cases of "dysfunctional" bleeding.

Estrogen binding sites and estrophilin histochemistry and their correlation with oestrogen receptor biochemistry

Since the application of mono- and poly-clonal antibodies to the estrogen receptor protein (estrophilin) classically admitted opinions about the interactions between estrogens and their target cells have changed. Biochemical assays of ER have been shown to provide false negative results; the key-mechanism seems to be located at the nuclear level, while until now most emphasis was put on cytosolic ER. In histochemistry, apparently contradictory reports have emphasized either cytoplasmic or nuclear labelling of estrogen binding sites (EBS). A lot of supputations have tried to explain in vitro translocations from the cytoplasm to the nucleus according to the physicochemical conditions which were used. Reading of some articles gives the impression that EBS histochemistry is yet an established and reliable method; commercially available histochemical "kits" may support this false idea. Therefore it is absolutely mandatory to intend to remain cautious and critical. Stepwise our knowledge is increasing; it is absolutely clear that the problems which did rise thanks to the "contradictory" histochemical studies gave a new impetus to both biochemical and histochemical research. Immunohisto- and cyto-chemistry of EBS and estrophilin go on in parallel and in correlation with biochemistry.

Mammary hyperplastic and preneoplastic changes: taxonomy and grading

Mammary lobular and ductal carcinoma in situ are thought to originate from preneoplastic precursors. Most of our knowledge on mammary tumorigenesis is based on experimental data obtained in rodents, which are focused on the biology of hyperplastic alveolar nodules (HAN). The morphology of HAN is analyzed and compared with possible analogous lesions in humans. The microarchitecture of the terminal duct lobular unit (TDLU) is described with reference to descriptions and nomenclature appearing in the literature. A comparison is intended between existing classifications of human hyperplastic and preneoplastic changes.

Present status of estrogen-receptor cytochemistry and its application in breast cancer research

Estradiol-BSA-FITC is an hydrophilic macromolecular analog used as a cytochemical marker of estrogen-binding sites. Because of the size of the molecule it seems that the reaction must be carried out on fresh-frozen cryostat sections. The freezing technique affects stainability, even as the freezing temperature. Post-fixation is used or not; the influence of various fixatives is variously interpreted. Thawing of the sections influences the intensity and localization of fluorescence. The concentration of E-BSA-FITC in the incubation medium plays a major role in the binding capacity of estrogen-receptors (ER). Fluorescence involves cytoplasm and/or the nucleus. The specificity of labelling on control sections by different methods of inhibition is variously appreciated. The threshold of ER-positivity varies from 10 to 90% of the cells. Standardization of the procedure, if possible, is highly desirable as much as the interpretation rules of the results.

A clinicopathological study of IUD users with special reference to endometrial patterns and endometritis

A group of 65 IUD users was studied during a period of 165 years of use, with a mean of 2.6 +/- 1.7 years per woman. The main complaint which differed significantly from the 120 controls was the occurrence of spotting in 33.8% of IUD users. Normal endometrial mucosae were found in 36.9% of IUD users and 38.7% of controls. Chronic endometritis was evidenced in 35.4% of IUD users versus 12.5% of controls; the former were asymptomatic in 25.0% of the cases. 39.1% of them had normal endometrial synchrony. Chronic endometritis occurred 2.2 +/- 1.3 years after insertion of the device. Endometritis was always symptomatic in controls; only 13.3% of them exhibited endometrial synchrony. The fundamental mechanism(s) responsible for the contraceptive efficiency of intrauterine contraceptive devices (IUD) remains a subject of controversy and a field of investigation. The most recent studies are essentially directed towards the biochemical analysis of uterine fluid [1]. Nevertheless, the presence of an inflammatory process, either morphologically or biochemically detectable, seems to be one of the fundamental modifications induced by the IUD. Since a certain reluctance to use IUDs has been observed in some countries, which has been ascribed mainly to contradictory reports on the risk of pelvic inflammatory disease (PID) in women wearing such devices [2], we found it interesting to intend to objectivate and reevaluate the influence of IUD on chronic aspecific endometritis, a possible precursor state of salpingitis and PID.

Direct influence of the three natural estrogens on human mammary gland in vitro

The direct influence of the three basic natural estrogens, estrone, 17 beta-estradiol and estriol, on DNA synthesis in human normal mammary epithelial cells was investigated in organ culture during 7 days, and was assessed by autoradiography. A threshold concentration of I.O. ng per ml was needed to elicit a significant stimulation by estradiol and estriol. No significant increase in the incorporation of tritiated-thymidine could be obtained with estrone in the same conditions. These observations are in keeping with the hypothesis put forward by Gurpide, Tseng and Gusberg (1977) that estrone per se might be devoid of any direct estrogenic effect.

Clinicopathologic hallmarks of mammary tubular carcinoma

Tubular carcinoma of the human breast is a rather uncommon neoplasm, which is characterized by particular histopathologic features and which seems to be either "scored down" (as grade I carcinoma) or overdiagnosed. Since this special variant of mammary cancer has been shown to respond more favorably to therapy than do common infiltrating carcinomas, its recognition as a genuine entity is important. Nineteen cases were studied and compared with the 110 tubular carcinomas reported in the literature. The basic clinicopathologic and histopathologic characteristics of true tubular carcinoma are discussed.

The diffuse endocrine system and derived tumours. Histological and histochemical characteristics

The Diffuse Endocrine System, to which the so-called APUD (Amine Precursor Uptake and Decarboxylation) cells do belong, gives rise to a group of tumours which may or not secrete amines and/or polypeptide hormones: carcinoids (argentaffinomas, argentaffin or Kultschitzky cell carcinomas). Foregut carcinoids are predominantly of B type (trabecular), argyrophilic, or non-reactive (in about 70% of cases) to silver impregnation. Midgut tumours are generally of A type (insular); more than 80% of them are argentaffinic. Hindgut derived carcinoids are primarily of mixed type; nearly 70% are non-reactive to silver stains. From a cytological standpoint all types may be build up of either small-round, spindle-shaped, polyhedral or cuboidal cells. From a functional point-of-view, the cells are either clear and immature, non-reducing or exhausted. Accordingly, the diagnosis cannot be based alone on silver impregnation or other histochemical methods.

Recent progress in the histological typing of human breast tumours

Recently, new concepts in the histological typing of human mammary carcinomas have been proposed. The basic subdivision into the two major categories, i.e. ductal and lobular carcinomas, remains valid. In so far as lobular carcinomas are concerned, histological variants have been recognized: invasive carcinoma without an in situ component as well as solid and signet-ring cell forms. Special types of duct carcinoma have been defined with more accuracy, those deserving special attention being, scirrhous, tubular and secretory forms. The validity of the diagnosis of so-called apocrine carcinoma is discussed, as is the place of mucus-secreting tumours in the histologic classification.

Diaminobenzidine histochemistry in light microscopy

Basically the DAB-technique localizes 3 enzymes, i.e. peroxidase, catalase, and cytochrome oxidase, but also pseudoperoxidatic activity of hemeenzymes (hemoglobin, myoglobin, etc.). Although at the ultrastructural level, i.e. in cytochemistry, the appropriate conditions for specific identification of each of these enzymatic activities have been extensively studied and reported in the literature, the subject remains open to investigation. In light microscopy DAB staining has been less thoroughly studied. Since DAB histochemistry might have practical interest in daily diagnostic pathology, it appeared worthwhile to work out a method convenient for paraffin embedded tissues. The method consisted of a prolonged incubation 48 h) of small tissue blocks, which had been prefixed for 1 h in 4% formaldehyde. Dehydration and rehydration occurred in graded ethanols; counterstain was obtained by toluidine blue. Although further experiments are needed to specify the physico-chemical conditions for the three enzymatic activities, the results are morphologically superior to that of frozen sections.

Prognostic implications of mean nuclear diameter in breast cancer

The mean nuclear diameter of 100 breast cancers was measured on tissue sections, to evaluate its importance for early prognosis. The cases were subdivided into 3 subgroups: small (25.5% of cases), medium (63.3%) and large (11.2%) nuclei. Early recurrence and mortality rates were investigated in each of the categories. Increasing nuclear size was shown to be related to mortality from metastatic disease. However, large-nucleus tumours had an inverse relationship with lymphnode involvement and possibly with recurrence rate. Hence, in our material nuclear size as a sole criterion was not a good indicator of the early behaviour of operable breast cancer.

Scirrhous carcinoma of the female breast

A series of 200 consecutive breast cancers as studied retrospectively. All of the diagnoses were reviewed without knowledge of the initial response; special attention was given to the true scirrhous carcinoma of the female breast, a special form of infiltrating duct carcinoma. Seven cases, an incidence of 3.5 per cent, fulfilled the diagnostic criteria: dense and hyaline connective tissue stroma, evenly distributed throughout the tumour and at its borders and which compressed pleomorphic and scanty carcinoma cells, almost without duct formation. Ten cases, an incidence of 5.0 per cent, were initially diagnosed as scirrhous tumours but have been reclassified as pseudo-scirrhous cancers. The commonest error seems to be the confusion between true scirrhous mammary cancer and infiltrating lobular carcinoma.

Estriol-induced dose-dependent DNA synthesis in normal human mammary epithelium in vitro

Normal human adult resting mammary gland explants were cultured during 7 days. The influence of hormones on DNA synthesis was assessed by autoradiography after incubation with tritiated-thymidine. Estriol was added to the medium at 3 different concentrations. With 0.01 ng/ml the labeling index remained at the level observed in the controls in the basic unenriched medium. A 10- and 100-fold increase of estriol elicited a transient, significant and dose-related increase of DNA synthesis on the 2nd day of organ culture. Estriol gave a qualitatively different profile of DNA synthesis than estradiol at 1.0 ng/ml. The results are compared with the effect of progesterone.

Nuclear diameters of breast cancer cells in tissue sections

Nuclear diameters of breast cancer cells were measured on tissue sections in 100 cases. Processing the tissues for histology caused significant shrinkage and distortion of structures. Comparison between nuclear diameters measured on cytologic specimens and those measured on tissue sections must take into account a correction factor of 1.55 x. "Small nuclei only" were not found; in 19% of the tumors a "small nuclear type predominance" was evident. Twelve percent of the cases fell into the category of "more than 30% large nuclei" according to the cytologic criteria corrected for tissue sections. The importance of the correction factor is emphasized.

Difficulties involved in diaminobenzidine histochemistry of endogenous peroxidase

Basically peroxidase (PO) histochemistry is used in different areas: haematologic physiopathology, estrogen-dependent genito-mammary physiopathology and immunoperoxidase histochemistry, both in electron microscopic cytochemistry and at the light microscopic level. In immunochemistry, endogenous peroxidatic activity is inhibited by means of various procedures. On the contrary, in haematology and in reproduction biology stainability of endogenous PO is mandatory; controls are achieved using different inhibitors. Literature data on the most appropriated technical conditions concerning fixation, processing and incubation, for PO staining are reviewed.

Granulocytes in the endometrium of post-partum women

Endometrial samples of women at various stages of gonadal activity after parturition were examined for the presence and numbers of endometrial granulocytes. Although samples at all the stages contained significant numbers of the granulocytes (i.e. greater than 7/high-power field), the 100% values for late-proliferative and adaptation hyperplasia were significantly higher than the values for the resting (81.8%), early (82.4%) and mid- (87.9%) proliferative and secretory (83.3%) phases. We suggest that this correlates with the suggestion that the granulocytes constitute a receptor system for oestrogens.

A modified levanol fast cyanine 5RN staining method for myoepithelial cells

The specificity of the tannic acid--phosphomolybdic acid--Levanol Fast Cyanine 5RN procedure for myosin-like proteins in myoepithelial cells is hampered by the affinity of the dye for other structures. The selectivity of myoepithelial cell staining is enhanced by oxidation of sections, nuclear staining by Safranin-O, and differentiation with Tartrazine.

Diagnostic aid of endometrium biopsy

The 784 cases, from which 701 complained of abnormal uterine bleeding, were reviewed by age groups, presenting symptoms, sex steroid medication and endometrial findings. Endometrial polyps and endometritis, which showed an incidence of 17.5 and 10.0%, respectively, were correlated with clinicopathologic findings. Peri- and postmenopausal bleeders were investigated with special reference to hormone therapy and endometrial patterns. Dysfunctional uterine bleeding was diagnosed in 48.7% of the subjects during reproductive years. Pathologic findings were found to explain the clinical symptoms in 60.6% of the entire study group.

Nonspecific alkaline phosphatase activity in normal and diseased human breast

Nonspecific alkaline phosphatase activity was identified in human normal and diseased breasts with the use of the calcium-cobalt, the lead-nitrate, and the azo-dye methods. The results varied not only with the staining method, but also with the functional status of the breast structures. In normal, dysplastic, and fibroadenomatous tissues there was a strong parallelism between myoepithelial and capillary enzyme activities. The calcium-cobalt method was the only technique which allowed staining of carcinoma cells; cancer stromal enzyme activity was evidenced only with the use of the same method. Our findings suggest that nonspecific alkaline phosphatase activity probably reflects a functional status of the labelled structures; the enzyme activity of myoepithelial cells is variable and not really specific.

ATPase activity in the breast: a comparison between three methods

Adenosine triphosphatase enzymatic activity was investigated in human approximatively normal, dysplastic and neoplastic mammary tissue, by three different methods. Staining intensity varied within wide limits; myoepithelial cells and blood vessels showed similar enzymatic activity. Epithelial cells reacted only faintly, or not at all; carcinoma cells were never labelled. Stromal response was highly variable. The calcium-cobalt method of Padykula and Herman gave more intense reactions than the lead-nitrate procedure of Wachstein and Meisel, either in the original form or according to the modifications recommended by Russo and Wells. With the latter method the sharpness of stain deposits on the different structures was markedly enhanced. The functional significance of ATPase activity is discussed.

Morphological changes in the amniotic epithelium in relation to placental weight and fetal maturity

A series of 52 placentas from the 36th week of gestation up to post-maturity was studied. The amniotic epithelium was studied with special regard to the morphological signs of maturation known to occur during this period. The results of the dating were compared with the presumed clinical age of the pregnancy and with the placental weight. A good correlation was found in 42.3% of the cases; the clinical age was overscored in 17.3% and underestimated in 40.4% of the subjects. No clear correlation was found between placental weight and histologic dating of the amniotic epithelium. The significance of the lipid laden amnios cells is discussed.

Effect of hormone on human mammary duct in vitro

Human mammary ducts were maintained in median-term organ culture. DNA synthesis was assessed by the uptake of 3H-thymidine in epithelial cells; labeling indices were counted on autoradiographies. DNA synthesis grossly remained between starting values in the basic conditions without hormones. Insulin (5 microgram/ml) did not stimulate the uptake of the isotope as compared with the controls. Estradiol (0.001 microgram/ml) and progesterone (1 microgram/ml) highly significantly enhanced DNA synthesis; subsequent waves did occur.

Granulocytic-like cells in the human fallopian tube

In the fallopian tube there are three main epithelial cell types, i.e., ciliated and nonciliated (or secretory) cells and intercalary, or peg, cells. An additional cell type has been considered either a wandering or a progenitor cell. Our morphologic and histochemical study shows a close similarity between a fourth cell type in the fallopian epithelium and the endometrial granulocytes (K cells). It is suggested that the two cells might be of an identical nature and that granulocytes could be ubiquitous in the entire Müllerian tract.

The percentage of granulocyte-like cells in human oviduct epithelium

The ratio of granulocyte-like cells to epithelial cells was examined in the fimbriae, ampullary, and isthmic regions of oviducts obtained from normal women of reproductive age, from postpartum women, from menopausal women, from women on combined oral contraceptives and from women with adnexal pathology. Only patients on oral contraceptives had a significantly high percentage of granulocyte-like cells as did one patient with acute salpingitis.

Effect of ovarian steroids on DNA synthesis in explanted human adult resting mammary tissues

A study has been made on the selective influence of the ovarian steroids, estradiol and progesterone, on three distinct parts of cultured, explanted human adult resting mammary tissue: lobules, interlobular and large ducts. The addition of estradiol elicited the highest stimulation of 3H-thymidine incorporation in large ducts. When progesterone was added DNA synthesis occurred mainly in interlobular ducts. The isolated action of both steroids on lobules was quantitatively comparable, but the time sequence of DNA synthesis was different. The possible significance of these findings is discussed.

Histologic classification of pure primary epithelial breast cancer

Current classifications of breast cancer are based on either morphologic descriptive or histogenetic criteria. The positive features and shortcomings of the most commonly used systems are presented. Our knowledge of breast cancer leads validity to a histogenetic topographic classification, a modification of which is suggested.

Appraisals and pitfalls of myoepithelial cell staining by Levanol Fast Cyanine 5RN

In the search for specific staining of myoepithelial cells in human normal and pathologic mammary tissue we applied the milling dye Levanol (Supranol) Fast Cyanine 5RN. Reports from literature on this staining method were considered, and efforts were made to improve the procedure. Different fixatives were tested, and the pretreatment of the sections was modified. Five nuclear stains were tried but were finally omitted. Counterstain of the connective tissue proved useful. The advantages of the different modifications are discussed.

Studies on the possible influence of the so-called wound healing reaction on DNA synthesis in organ culture

Tissue sectioning is a necessary preliminary step in the preparation of organ culture explants. The real extent of tissue damage in the "wound healing reaction" can be assessed by DNA isotopic labeling. The differential count of labeling indices between epithelial structures located at the margin of the explants and similar structures near the center was used to study the influence of tissue damage on DNA synthesis. Our results suggest a time-related influence of wound healing on labeling indices. This reaction has to be taken into account when DNA synthesis is used as an indicator of hormonedependency in vitro.