Circumvention of over-excitation of PSII by maintaining electron transport rate in leaves of four cotton genotypes developed under long-term drought.

We investigated the patterns of response to a long-term drought in the field in cotton cultivars (genotypes) with known differences in their drought tolerance. Four cotton genotypes with varying physiological and morphological traits, suited to different cropping conditions, were grown in the field and subjected to a long-term moderate drought. In general, cotton leaves developed under drought had significantly higher area-based leaf nitrogen content (N (area)) than those under well irrigation. Droughted plants showed a lower light-saturated net photosynthetic rate (A (sat)) with lower stomatal conductance (g (s)) and intercellular CO (2) concentration (C (i)) than irrigated ones. Based on the responses of A (sat) to g (s) and C (i), there was no decreasing trend in A (sat) at a given g (s) and C (i) in droughted leaves, suggesting that the decline in A (sat) in field-grown cotton plants under a long-term drought can be attributed mainly to stomatal closure, but not to nonstomatal limitations. There was little evidence of an increase in thermal energy dissipation as indicated by the lack of a decrease in the photochemical efficiency of open PSII (F (v)'/F (m)') in droughted plants. On the basis of electron transport (ETR) and photochemical quenching (q (P)), however, we found evidence indicating that droughted cotton plants can circumvent the risk of excessive excitation energy in photosystem (PS) II by maintaining higher electron transport rates associated with higher N (area), even while photosynthetic rates were reduced by stomatal closure.

Light compensation points in shade-grown seedlings of deciduous broadleaf tree species with different successional traits raised under elevated CO2.

We measured leaf photosynthetic traits in shade-grown seedlings of four tree species native to northern Japan, raised under an elevated CO2 condition, to investigate the effects of elevated CO2 on shade tolerance of deciduous broadleaf tree species with different successional traits. We considered Betula platyphylla var. japonica and Betula maximowicziana as pioneer species, Quercus mongolica var. crispula as a mid-successional species, and Acer mono as a climax species. The plants were grown under shade conditions (10% of full sunlight) in a CO2 -regulated phytotron. Light compensation points (LCPs) decreased in all tree species when grown under elevated CO2 (720 µmol·mol(-1) ), which were accompanied by higher apparent quantum yields but no photosynthetic down-regulation. LCPs in Q. mongolica and A. mono grown under elevated CO2 were lower than those in the two pioneer birch species. The LCP in Q. mongolica seedlings was not different from that of A. mono in each CO2 treatment. However, lower dark respiration rates were observed in A. mono than in Q. mongolica, suggesting higher shade tolerance in A. mono as a climax species in relation to carbon loss at night. Thus, elevated CO2 may have enhanced shade tolerance by lowering LCPs in all species, but the ranking of shade tolerance related to successional traits did not change among species under elevated CO2 , i.e. the highest shade tolerance was observed in the climax species (A. mono), followed by a gap-dependent species (Q. mongolica), while lower shade tolerance was observed in the pioneer species (B. platyphylla and B. maximowicziana).

Canopy-level stomatal narrowing in adult Fagus sylvatica under O3 stress - means of preventing enhanced O3 uptake under high O3 exposure?

Spatio-temporally consistent O(3) doses are demonstrated in adult Fagus sylvatica from the Kranzberg Forest free-air fumigation experiment, covering cross-canopy and whole-seasonal scopes through sap flow measurement. Given O(3)-driven closure of stomata, we hypothesized enhanced whole-tree level O(3) influx to be prevented under enhanced O(3) exposure. Although foliage transpiration rate was lowered under twice-ambient O(3) around noon by 30% along with canopy conductance, the hypothesis was falsified, as O(3) influx was raised by 25%. Nevertheless, the twice-ambient/ambient ratio of O(3) uptake was smaller by about 20% than that of O(3) exposure, suggesting stomatal limitation of uptake. The O(3) response was traceable from leaves across branches to the canopy, where peak transpiration rates resembled those of shade rather than sun branches. Rainy/overcast-day and nightly O(3) uptake is quantified and discussed. Whole-seasonal canopy-level validation of modelled with sap flow-derived O(3) flux becomes available in assessing O(3) risk for forest trees.

Evaluation of perinatal outcome using individualized growth assessment: comparison with conventional methods.

OBJECTIVE: To evaluate individualized growth assessment using the Rossavik growth model for detection of growth-retarded neonates with poor perinatal outcomes. METHODS: Rossavik growth models derived from second-trimester ultrasound measurements were used to predict birth characteristics of 154 singleton neonates. Individual fetal growth curve standards for head and abdominal circumference and weight were determined from the data of two scans obtained before 25 weeks' menstrual age and separated by an interval of at least 5 weeks. Comparisons between actual and predicted birth characteristics were expressed by the Growth Potential Realization Index and the Neonatal Growth Assessment Score (NGAS). The proportions of perinatal outcomes (mechanical delivery, low Apgar score, abnormal fetal heart rate [FHR] patterns, neonatal acidosis, meconium staining of amniotic fluid, neonatal intensive care unit admission, and maternal complications), using NGAS, were compared with those by the traditional birth weight-for-gestational age method and the ponderal index, respectively. RESULTS: Of the 154 fetuses studied, 120 had normal growth outcomes at birth; 18 showed evidence of intrauterine growth retardation; and 16 had macrosomia, based on NGAS. According to birth weight-for-gestational age classification, 32 fetuses were small for gestational age; 118 were appropriate for gestational age; and only 4 were large for gestational age. According to the ponderal index, 55 fetuses had growth retardation, 99 showed appropriate growth and there was no macrosomia. There was a significant increase in mechanical deliveries in cases of growth-retarded neonates, determined using the NGAS classification, when compared with events related to normally grown or macrosomic neonates. However, there were no significant differences in mechanical deliveries among the groups by birth weight classification or ponderal index. Both birth weight classification and NGAS classification showed a significant increase in the low Apgar score, abnormal FHR patterns, and neonatal acidosis in infants classified as growth retarded when compared with appropriately grown or macrosomic infants. However, there were no significant differences in the low Apgar score, abnormal FHR patterns, and neonatal acidosis between growth-retarded and appropriately grown infants when they had been so classified by ponderal index. Three growth category classification methods failed to reveal significant differences in meconium staining of amniotic fluid, neonatal intensive care unit admission, and maternal complications among the groups. CONCLUSION: We do cast doubt on the usefulness of the ponderal index for detection of growth-retarded neonates with poor perinatal outcomes, and individualized growth assessment seems to perform at least as well as the traditional birth weight-for-gestational age method.

Intracardiac blood flow velocity waveforms in normal fetuses in utero.

Sixty-five continuous-wave Doppler ultrasonographic examinations were performed on 57 normal fetuses at 16 to 40 weeks of gestation. Maximal velocities of transmitral, transtricuspid, transaortic and transpulmonary blood flow velocity waveforms were assessed. Transmitral maximal velocity, transtricuspid maximal velocity, transaortic maximal velocity and transpulmonary maximal velocity correlated well with gestational age. The ratio of transtricuspid maximal velocity/transmitral maximal velocity was at least 1 in 44 of 45 fetuses (97.8%). In the ratio of transpulmonary maximal velocity/transaortic maximal velocity, the characteristic change was not evident. Therefore, continuous-wave Doppler ultrasonographic measurement of fetal intracardiac blood flow velocity waveforms in utero can aid in analyzing the physiologic circulatory hemodynamics.

Transvaginal Doppler ultrasound assessment of intratumoral hemodynamic change before and during hypertensive intra-arterial chemotherapy for uterine cancer.

OBJECTIVE: To evaluate blood flow in malignant uterine tumors during hypertensive intra-arterial chemotherapy. METHODS: Hypertensive intra-arterial chemotherapy (angiotensin II, cisplatin 100 mg, doxorubicin 40 mg) was given to two women with cervical cancer (stage IVA) and seven with endometrial cancer (three stage IA, one stage IB, two stage II, and one stage III). The intratumoral blood flow velocity waveforms were imaged by transvaginal Doppler ultrasound before and during the chemotherapy in six patients. RESULTS: The mean peak systolic velocity during hypertensive intra-arterial chemotherapy (58.9 +/- 29.3 cm/second) was significantly higher than that before chemotherapy (16.0 +/- 6.3 cm/second) (P < .05). There was a significant difference between the end-diastolic velocity before (5.2 +/- 1.8 cm/second) and during chemotherapy (21.2 +/- 6.8 cm/second) (P < .05). The resistance index value during hypertensive intra-arterial chemotherapy (0.607 +/- 0.094) fell significantly from that before therapy (0.644 +/- 0.119) (P < .05). Blood flow velocity waveforms in normal myometrial tissue could be recorded in three cases; in all, the diastolic flow noted before hypertensive intra-arterial chemotherapy disappeared during chemotherapy. CONCLUSION: These results suggest that hypertensive intra-arterial chemotherapy induces a selective marked increase of blood flow in uterine cancer.

Effect of dehydroepiandrosterone sulfate on uterine artery flow velocity waveforms in term pregnancy.

OBJECTIVE: To investigate the interrelation between estrogen synthesis by the fetoplacental unit and uteroplacental hemodynamics in term pregnancy. METHODS: Transvaginal color Doppler flow imaging and pulsed Doppler ultrasonographic assessments were made on ten normal full-term pregnant women before and 3, 5, 10, 30, and 60 minutes after the administration of a 200-mg intravenous dose of dehydroepiandrosterone sulfate (DHAS) in 20 mL of 5% dextrose. Ten normal full-term pregnant women received 20 mL of 5% dextrose as controls. The pulsatility index (PI) values for the uterine artery, heart rate, and mean arterial pressure were recorded. Plasma estradiol (E2) was measured before and 10 minutes after the infusion. RESULTS: In the DHAS group, uterine artery PI decreased from baseline by 26% (P < .05) after 5 minutes, and the mean reduction was 36% (P < .05) after 10 minutes and 15% (P < .05) after 30 minutes. The PI returned to the baseline value 60 minutes later. In the control group, there was no change in uterine artery PI. No change was found in heart rate or mean arterial blood pressure in the control or DHAS groups. The mean plasma E2 increased from 22.3 +/- 6.6 to 56.2 +/- 24.1 ng/mL (P < .05) 10 minutes after the infusion in DHAS subjects, whereas there was no significant change in plasma E2 in the controls. CONCLUSION: Dehydroepiandrosterone sulfate induces a significant decrease in the uterine artery PI, which suggests a possible decrease in uterine vascular impedance in term pregnancy.

A critical evaluation of transvaginal Doppler studies, transvaginal sonography, magnetic resonance imaging, and CA 125 in detecting ovarian cancer.

OBJECTIVE: To evaluate whether transvaginal Doppler ultrasound is more valid than transvaginal sonography, magnetic resonance imaging (MRI), and CA 125 in differentiating malignant from benign ovarian tumors. METHODS: Sixty-three patients with ovarian tumors (36 benign and 27 malignant) were studied with transvaginal Doppler ultrasound before surgery. Blood flow velocity waveforms arising from intratumoral and/or tumor surface arteries were assessed by calculating the resistance index. Transvaginal B-mode sonography and MRI imaging examinations were also conducted. Serum CA 125 levels were measured. RESULTS: There was a significant difference between the resistance index value (0.692 +/- 0.188) in benign tumors and the value (0.503 +/- 0.107) in malignant tumors (P < .05). When 0.72 (mean of the malignant tumor resistance index values + 2 standard deviations) was considered as the cutoff value of the resistance index, the sensitivity and specificity of the resistance index in detecting malignant ovarian tumors were 92.6 and 52.8%, respectively. These values did not differ significantly from those with transvaginal sonography diagnosis (sensitivity 85.2%, specificity 69.4%). The resistance index sensitivity was significantly higher than those with MRI diagnosis (66.7%) and CA 125 levels (59.3%) (P < .05); however, the resistance index specificity was significantly lower than those with MRI diagnosis (97.1%) and CA 125 levels (91.7%) (P < .05). CONCLUSION: Our results suggest that transvaginal Doppler ultrasound does not provide more useful diagnostic information than transvaginal sonography, MRI, and CA 125 for the differentiation of malignant from benign ovarian tumors.

The effect of serum obtained before and after treatment for endometriosis on in vitro development of two-cell mouse embryos.

OBJECTIVE: To evaluate the effect of serum obtained before and after treatment for endometriosis on in vitro development of two-cell mouse embryos. DESIGN: Pretreatment and post-treatment comparison of mouse embryo development in serum supplements from patients with endometriosis; results were compared using chi 2 analysis. SETTING: Infertility Clinic, Shimane Medical University, Izumo, Japan. PATIENTS: Ten consecutive women with endometriosis who underwent treatment for the disease. Seven women who were managed expectantly served as controls. INTERVENTIONS: All patients underwent laparoscopic or conservative surgery. This was followed by a 6-month course of either danazol 400 mg/d (6 patients) or buserelin acetate 900 micrograms/d (4 patients). MAIN OUTCOME MEASURE(S): Total number of embryos that reached blastocyst stage after 72 hours of incubation were compared before and after treatment. RESULTS: Before treatment, 23% of the embryos reached blastocyst stage, whereas 8 of the 10 serum samples were embryo toxic. After treatment, significantly more embryos (59%) developed to blastocysts, and only one serum sample remained embryo toxic. In the control group, there was no significant difference in the number of embryos that reached blastocyst stage after expectant treatment. CONCLUSION: The embryo toxicity of serum samples from patients with endometriosis is lost after treatment.

Magnetic resonance imaging using "fat-saturation" technique is useful for diagnosing small endometrioma: a case report.

Preoperative MRI using fat-saturation technique was performed in a patient with endometriosis. Endometrial implants as small as 3 mm were accurately diagnosed by MRI. The fat-saturation technique is useful for diagnosing small endometrioma.

Transvaginal ultrasonic assessment of the response to clomiphene citrate in polycystic ovarian syndrome.

OBJECTIVE: To study the relationship between some ovarian morphological findings based on transvaginal ultrasound (US) and the clomiphene citrate (CC) responsiveness in patients with polycystic ovarian syndrome (PCOS). DESIGN: A comparative study of ovarian US features between the CC responders and the CC nonresponders. SETTING: Infertility and Endocrine Clinic, Department of Obstetrics Gynecology, Shimane Medical University Hospital, Izumo, Japan. PATIENTS: Forty-seven infertile patients with PCOS and 30 healthy volunteers. INTERVENTIONS: A dose of 50 to 200 mg/d CC was given for ovulation induction in patients with PCOS. MAIN OUTCOME MEASURES: Ovarian volume and number of follicles; serum LH, FSH, T, delta 4 androstenedione, and DHEAS. RESULTS: The mean ovarian volume (11.9 mL) and the number of small follicles (13.0) were significantly larger in the CC nonresponders compared with those of the CC responders (7.9 mL and 7.0, respectively). Only 47% of the CC responders and 79% of the CC nonresponders had bilaterally enlarged ovaries (> 6.2 mL). Considerable overlap existed between the different groups. However, 96% of the CC nonresponders had a significantly increased number of follicles (> or = 10 follicles) in each ovary compared with that (16%) of the CC responders. Furthermore, with the combination of these parameters, none of the CC nonresponders had bilaterally normal ovaries, and 96% of patients with PCOS with bilaterally abnormal ovaries were CC nonresponsive. CONCLUSIONS: Small multiple follicles (> or = 10) and enlarged ovarian volume (> 6.2 mL) were the most prominent transvaginal US features of ovaries in patients with PCOS with CC nonresponsiveness. These US features could be clinically useful for distinguishing clearly a CC nonresponder from a CC responder.

Diagnosis of pelvic endometriosis by magnetic resonance imaging using "fat-saturation" technique.

OBJECTIVE: To assess the usefulness of fat-saturated magnetic resonance (MR) imaging for detecting small endometrial implants. DESIGN: Prospective evaluation by conventional and fat-saturated MR imaging. SETTING: Shimane Medical University Hospital, Izumo, Japan. PATIENTS: Fifty-one consecutive patients with clinically suspected pelvic endometriosis. INTERVENTIONS: Magnetic resonance images < 2 weeks before laparoscopy or laparotomy. MAIN OUTCOME MEASURE: The location, number, and size of lesions. RESULTS: Surgery revealed a normal pelvis in 5 patients, endometriosis in 44 (42 with pigmented lesions and 2 with nonpigmented lesions and adhesions), and other cystic lesions in 2. With fat-saturated MR imaging, overall sensitivity, specificity, positive predictive value, and negative predictive value were 89%, 71%, 95%, and 50%, respectively. At surgery, 122 pigmented lesions of endometriosis were detected. Conventional MR images indicated lesions of endometriosis in 74. When fat-saturated images were used, 103 lesions were detected. With conventional MR images, only one of 34 small endometrial implants (2 to 3 mm in diameter) was detected. However, the addition of fat-saturated images increased the detection rate to 15 of 34, and all lesions > 4 mm in diameter. CONCLUSION: Conventional MR imaging for detecting small endometrial implants was improved by addition of the fat-saturation technique. Therefore, fat-saturation MR imaging is an acceptable for detecting small endometriomas.

CA-125 is an effective marker for patients with external endometriosis and on danazol: case reports.

Serum levels of CA-125 in women with external endometriosis and on danazol were assayed for an extended period, and changes in the CA-125 pattern were analyzed. Whereas the prognosis for the patients in case 1 was good, those for cases 2, 3, and 4 were poor. We propose that the Ca-125 levels should be carefully determined for individual patients, because a relapse can be predicted.

Magnetic resonance imaging and serum CA-125 in evaluating patients with endometriomas prior to medical therapy.

OBJECTIVE: To determine whether magnetic resonance imaging (MRI) and serum levels of CA-125 can be used to evaluate patients with endometriomas before initiating medical treatment. DESIGN: Comparative study before and after medical treatment. SETTING: Shimane Medical University Hospital, Izumo, Japan. PATIENTS: Eleven consecutive patients with at least one endometrioma > 10 mm in maximal diameter that was diagnosed by laparoscopy and treated with 900 micrograms/d buserelin acetate for 6 months. INTERVENTIONS: Magnetic resonance imaging and blood sampling was performed < 2 weeks before laparoscopy. MAIN OUTCOME MEASURES: Signal intensity of edometrioma/signal intensity of gluteus maximum muscle on T2-weighted image (T2SI:MSI); volume of endometrioma and serum CA-125. RESULTS: There was a positive linear correlation (r = 0.787) between T2SI:MSI before treatment and the extent of decrease in the volume of endometrioma. There was a negative linear relationship between serum CA-125 before treatment and the mean extent of decrease in the cyst volume (r = 0.678). The reduction in volume of endometrioma and T2SI:MSI before treatment related to the outcome of patients. CONCLUSION: The T2SI:MSI on MRI and serum CA-125 may be useful for estimating the outcome of patients with endometriomas before initiating medical treatment.

Ovarian cystic teratomas: value of chemical fat saturation magnetic resonance imaging.

Chemical fat saturation (FS) magnetic resonance imaging (MRI) for the characterization of ovarian cystic teratoma was evaluated in 19 patients with 22 lesions. The tumour was evaluated for signal intensity, location and size; the presence of chemical shift artefact, debris and fat-fluid level. Ovarian cystic teratoma was diagnosed prospectively if the mass contained fat and/or more than one type of internal pattern on (1) SE T1-, T2-, (2) SE T1-, T2-, FS T1-weighted images. A correct diagnosis was reached in 17 of 22 tumours on conventional T1- and T2-weighted images, and in 21 of 22 tumours when fat-saturation images were added. When fat-saturation images were added, four of five tumours misdiagnosed on conventional images were then correctly diagnosed. These tumours contained only small amounts of fat. Fat-saturation images could detect smaller amounts of fat than conventional images. However, one tumour did not show decreased intensity on fat saturation images, and was not diagnosed even when fat-saturation images were added. Fat saturation images have been shown to be of value in diagnosing cystic teratomas.

Leaf morphology and photosynthetic adjustments among deciduous broad-leaved trees within the vertical canopy profile.

Photosynthetic acclimation of deciduous broad-leaved tree species was studied along a vertical gradient within the canopy of a multi-species deciduous forest in northern Japan. We investigated variations in (1) local light regime and CO2 concentration ([CO2]), and (2) morphological (area, thickness and area per mass), biochemical (nitrogen and chlorophyll concentrations) and physiological (light-saturated photosynthetic rate) attributes of leaves of seven major species on three occasions (June, August and October). We studied early successional species, alder (Alnus hirsuta (Spach) Rupr.) and birch (Betula platyphylla var. japonica (Miq.) Hara); gap phase species, walnut (Juglans ailanthifolia Carrière) and ash (Fraxinus mandshurica var. japonica Rupr.); mid-successional species, basswood (Tilia japonica (Miq.) Simonk.) and elm (Ulmus davidiana var. japonica (Rehd.) Nakai); and the late-successional species, maple (Acer mono Bunge). All but maple initiated leaf unfolding from the lower part of the crown. The [CO2] within the vertical profile ranged from 320-350 ppm in the upper canopy to 405-560 ppm near the ground. The lowest and highest ambient [CO2] occurred during the day and during the night, respectively. This trend was observed consistently during the summer, but not when trees were leafless. Chlorophyll concentration was positively related to maximum photosynthetic rate within, but not among, species. Leaf senescence started from the inner part of the crown in alder and birch, but started either in the outer or top portion of the canopy of ash, basswood and maple. Chlorophyll (Chl) to nitrogen ratio in leaves increased with decreasing photon flux density. However, Chl b concentration in all species remained stable until the beginning of leaf senescence. Maximum photosynthetic rates observed in sun leaves of early successional species, gap phase or mid-successional species, and late successional species were 12.5-14.8 micromol m(-2) s(-1), 4.1-7.8 micromol m(-2) s(-1) and 3.1 micromol m(-2) s(-1), respectively.

Comparison of photosynthetic responses to manganese toxicity of deciduous broad-leaved trees in northern Japan.

The effects of manganese (Mn) toxicity on photosynthesis of four tree species in northern Japan representing different successional traits were examined. The four species are: Betula ermanii (Be) and Alnus hirsuta (Ah) representing two early successional species, Ulmus davidiana var. japonica (Ud) as the mid-successional species, and Acer mono (Am) as the late successional species. Seedlings were grown hydroponically in a solution containing nutrients and Mn of four concentrations (1, 10, 50, 100 mg litre(-1)) for 50 days. Gas exchange measurements indicate that in all species, Mn accumulation in leaves resulted in the decline of light-saturated net photosynthetic rate ai ambient CO(2) pressure (35 Pa, Pn(amb)) and at saturating (5%) CO(2) pressure (Pn(sat)), and of carboxylation efficiency but has little effect on the maximum efficiency of photochemistry. Sensitivity to elevated levels of Mn differed among species where the decline of Pn(amb) was much more modest in the two early successional species of Be and Ah than the mid- and late successional species of Ud and Am. The same trends were observed in both Pn(sat) and carboxylation efficiency. Based on these results, we suggest that early successional species (Betula ermanii and Alnus hirsuta) have greater tolerance for excess Mn in leaves than mid- and late successional species.

Manganese toxicity as indicated by visible foliar symptoms of Japanese white birch (Betula platyphylla var. japonica).

For the purpose of a field diagnosis of Mn toxicity, we showed the possibility of using visible foliar symptoms of Japanese white birch (Betula platyphylla var. japonica Hara) as indicator. To examine the relationship between the expression of visible symptoms and leaf Mn concentrations, white birch seedlings were grown under four different Mn levels: 1 mg Mn l-1 as control, 10, 50 and 100 mg Mn l-1. Foliar symptoms of Mn toxicity for white birch were: (1) chlorosis at entire young leaves in the 50 and 100 mg Mn l-1 treatments; and (2) brown speckles at the leaf marginal and interveinal area for old leaves in the treatments greater than 1 mg Mn l-1. Mn preferably accumulated into the leaf marginal and interveinal area, where the brown speckles were observed. The mechanism determining the expression of symptoms seems to be associated with the physiological state related to leaf age as well as Mn distribution and concentration within a leaf.

Effects of deicing salt on the vitality and health of two spruce species, Picea abies Karst., and Picea glehnii Masters planted along roadsides in northern Japan.

In northern Japan, the growth of Picea abies Karst., and Picea glehnii Masters, which have been planted along the highways, is often suppressed due to several environmental stresses. To examine the adverse effects of deicing salt, the primary source of stress,we measured needle life span, photosynthetic capacity, and water potential and transpiration rate of the two spruce species at a site with damaged trees, near the roadside and a site with healthy trees, located far from the highway. Results from the analysis showed large amounts of sodium and chlorine in the soil and snow at the damaged site. These elements had accumulated in the needles of the spruce. Moreover, physiological traits of the spruce, at the damaged site were also affected. Therefore, we concluded that poor physiological traits might be attributed to an accumulation of deicing salt in the needles, resulting in the suppression of tree growth.

Immunohistochemical studies of the uterine cervix after CO2 laser conization.

OBJECTIVE: To investigate the process of the maturation of cervical epithelium after CO2 laser conization. METHOD: Specimens from the uterine cervix (248) resected from 31 premenopausal females who had hysterectomy after CO2 laser conization were studied with 2 kinds of anti-keratin monoclonal antibodies (PKK-1, KL-1). RESULT: (i) The epithelium covered stroma after 4-6 weeks. (ii) In the normal S-C junction, KL-1 was localized to the middle and upper layers, and PKK-1 to the basal layer. (iii) The staining patterns of KL-1 and PKK-1 in the S-C junctions after conization could be classified into 4 groups according to localization and staining intensity. (iv) The S-C junction appeared normal in all specimens 7 weeks after conization. CONCLUSION: The regenerating epithelium covered the stroma within 4-6 weeks, but resolution of squamous epithelial metaplasia only occurred 7 weeks after conization.