Sampling rate requirement for accurate calculation of heart rate and its variability based on the electrocardiogram

Objective. To develop analytical formulas which can serve as quantitative guidelines for the selection of the sampling rate for the electrocardiogram (ECG) required to calculate heart rate (HR) and heart rate variability (HRV) with a desired level of accuracy.Approach. We developed analytical formulas which relate the ECG sampling rate to conservative bounds on HR and HRV errors: (i) one relating HR and sampling rate to a HR error bound and (ii) the others relating sampling rate to HRV error bounds (in terms of root-mean-square of successive differences (RMSSD) and standard deviation of normal sinus beats (SDNN)). We validated the formulas using experimental data collected from 58 young healthy volunteers which encompass a wide HR and HRV ranges through strenuous exercise.Main results. The results strongly supported the validity of the analytical formulas as well as their tightness. The formulas can be used to (i) predict an upper bound of inaccuracy in HR and HRV for a given sampling rate in conjunction with HR and HRV as well as to (ii) determine a sampling rate to achieve a desired accuracy requirement at a given HR or HRV (or its range).Significance. HR and its variability (HRV) derived from the ECG have been widely utilized in a wide range of research in physiology and psychophysiology. However, there is no established guideline for the selection of the sampling rate for the ECG required to calculate HR and HRV with a desired level of accuracy. Hence, the analytical formulas may guide in selecting sampling rates for the ECG tailored to various applications of HR and HRV.

Artificial intelligence methods to estimate overall mortality and non-relapse mortality following allogeneic HCT in the modern era: an EBMT-TCWP study

Allogeneic haematopoietic cell transplantation (alloHCT) has curative potential counterbalanced by its toxicity. Prognostic scores fail to include current era patients and alternative donors. We examined adult patients from the EBMT registry who underwent alloHCT between 2010 and 2019 for oncohaematological disease. Our primary objective was to develop a new prognostic score for overall mortality (OM), with a secondary objective of predicting non-relapse mortality (NRM) using the OM score. AI techniques were employed. The model for OM was trained, optimized, and validated using 70%, 15%, and 15% of the data set, respectively. The top models, "gradient boosting" for OM (AUC = 0.64) and "elasticnet" for NRM (AUC = 0.62), were selected. The analysis included 33,927 patients. In the final prognostic model, patients with the lowest score had a 2-year OM and NRM of 18 and 13%, respectively, while those with the highest score had a 2-year OM and NRM of 82 and 93%, respectively. The results were consistent in the subset of the haploidentical cohort (n = 4386). Our score effectively stratifies the risk of OM and NRM in the current era but do not significantly improve mortality prediction. Future prognostic scores can benefit from identifying biological or dynamic markers post alloHCT.

A Physical Model-Based Approach to One-Point Calibration of Pulse Transit Time to Blood Pressure

OBJECTIVE

To develop a novel physical model-based approach to enable 1-point calibration of pulse transit time (PTT) to blood pressure (BP).

METHODS

The proposed PTT-BP calibration model is derived by combining the Bramwell-Hill equation and a phenomenological model of the arterial compliance (AC) curve. By imposing a physiologically plausible constraint on the skewness of AC at positive and negative transmural pressures, the number of tunable parameters in the PTT-BP calibration model reduces to 1. Hence, as opposed to most existing PTT-BP calibration models requiring multiple (≥2) PTT-BP measurements to personalize, the PTT-BP calibration model can be personalized to an individual subject using a single PTT-BP measurement pair. Equipped with the physically relevant PTT-AC and AC-BP relationships, the proposed approach may serve as a universal means to calibrate PTT to BP over a wide BP range. The validity and proof-of-concept of the proposed approach were evaluated using PTT and BP measurements collected from 22 healthy young volunteers undergoing large BP changes.

RESULTS

The proposed approach modestly yet significantly outperformed an empiric linear PTT-BP calibration with a group-average slope and subject-specific intercept in terms of bias (5.5 mmHg vs 6.4 mmHg), precision (8.4 mmHg vs 9.4 mmHg), mean absolute error (7.8 mmHg vs 8.8 mmHg), and root-mean-squared error (8.7 mmHg vs 10.3 mmHg, all in the case of diastolic BP).

CONCLUSION

We demonstrated the preliminary proof-of-concept of an innovative physical model-based approach to one-point PTT-BP calibration.

SIGNIFICANCE

The proposed physical model-based approach has the potential to enable more accurate and convenient calibration of PTT to BP.

Pharmacologic treatment of kidney stones: Current medication and pH monitoring

Nephrolithiasis is a globally prevalent urologic condition associated with significant morbidity and patient discomfort. Current management of kidney stones includes both surgical and pharmacologic interventions. Though surgery may be necessary under certain circumstances, pharmacologic treatment is a more affordable, readily available, and a less invasive option for patients. A comprehensive scoping review was conducted to summarize the available literature on the pharmacologic strategies for managing the predominant stone types including calcium oxalate, calcium phosphate, uric acid, struvite, and cystine stones. Central to these therapeutic approaches is the regulation of factors such as urine pH, stone crystallization, and patient metabolics that precipitate stone development and growth. This review highlights the pharmacological options available for treating each kidney stone type, emphasizing the importance of patient tailored medical management that should be considered by every physician.

Classification of Blood Volume Decompensation State via Machine Learning Analysis of Multi-Modal Wearable-Compatible Physiological Signals

This paper presents a novel computational algorithm to estimate blood volume decompensation state based on machine learning (ML) analysis of multi-modal wearable-compatible physiological signals. To the best of our knowledge, our algorithm may be the first of its kind which can not only discriminate normovolemia from hypovolemia but also classify hypovolemia into absolute hypovolemia and relative hypovolemia. We realized our blood volume classification algorithm by (i) extracting a multitude of features from multi-modal physiological signals including the electrocardiogram (ECG), the seismocardiogram (SCG), the ballistocardiogram (BCG), and the photoplethysmogram (PPG), (ii) constructing two ML classifiers using the features, one to classify normovolemia vs. hypovolemia and the other to classify hypovolemia into absolute hypovolemia and relative hypovolemia, and (iii) sequentially integrating the two to enable multi-class classification (normovolemia, absolute hypovolemia, and relative hypovolemia). We developed the blood volume decompensation state classification algorithm using the experimental data collected from six animals undergoing normovolemia, relative hypovolemia, and absolute hypovolemia challenges. Leave-one-subject-out analysis showed that our classification algorithm achieved an F1 score and accuracy of (i) 0.93 and 0.89 in classifying normovolemia vs. hypovolemia, (ii) 0.88 and 0.89 in classifying hypovolemia into absolute hypovolemia and relative hypovolemia, and (iii) 0.77 and 0.81 in classifying the overall blood volume decompensation state. The analysis of the features embedded in the ML classifiers indicated that many features are physiologically plausible, and that multi-modal SCG-BCG fusion may play an important role in achieving good blood volume classification efficacy. Our work may complement existing computational algorithms to estimate blood volume compensatory reserve as a potential decision-support tool to provide guidance on context-sensitive hypovolemia therapeutic strategy.

Posture-Dependent Variability in Wrist Ballistocardiogram-Photoplethysmogram Pulse Transit Time: Implication to Cuff-Less Blood Pressure Tracking

OBJECTIVE

Toward the ultimate goal of robust cuff-less blood pressure (BP) tracking with wrist wearables against postural changes, the goal of this work was to investigate posture-dependent variability in pulse transit time (PTT) measured with ballistocardiogram (BCG) and photoplethysmogram (PPG) signal pair at the wrist.

METHODS

BCG and PPG signals were acquired from 25 subjects under the combination of 3 body (standing, sitting, and supine) and 3 arm (vertical in head-to-foot direction, placed on the chest, and holding a shoulder) postures. PTT was computed as the time interval between the BCG J wave and the PPG foot, and the impact of the 9 postures on PTT was analyzed by invoking an array of possible physical mechanisms.

RESULTS

Our work suggests that (i) wrist BCG-PPG PTT is consistent under standing and sitting postures with vertically held arms; and (ii) changes in wrist orientation and height as well as restrictions in body and arm movement may alter wrist BCG-PPG PTT via distortions in the wrist BCG and PPG waveforms. The results indicate that wrist BCG-PPG PTT varies with respect to postures even when BP remains constant.

CONCLUSION

The potential of cuff-less BP tracking via wrist BCG-PPG PTT demonstrated under standing posture with arms vertically down in the head-to-foot direction may not generalize to other body and arm postures.

SIGNIFICANCE

Understanding the physical mechanisms responsible for posture-induced BCG-PPG PTT variability may increase the versatility of the wrist BCG for cuff-less BP tracking.

Effects of biocompatible Nanofillers on mixed-mode I and II fracture toughness of PMMA base dentures

A modified single edge cracked bend beam specimen called "inclined edge crack asymmetric bend" (IE-CAB) specimen was designed and proposed for investigating mixed mode I/II fracture toughness behavior of brittle materials. Using a large number of finite element analyses performed for different geometry and loading conditions, it was demonstrated that unlike the conventional single edge notch beam specimen, the IE-CAB configuration can provide full combinations of mode mixities from pure mode I to pure mode II. Then the IE-CAB specimen was employed for mixed mode I/II fracture toughness testing of two PMMA based denture materials (i.e. neat PMMA and toughened PMMA with Nano-hydroxyapatite (HAP)and Nano-alumina (Al₂O₃) particles). The obtained experimental results showed that adding bio-compatible (HAP and Al₂O₃) Nano-particles can increase both modes I and II fracture resistance (K_Ic and K_IIc) values of base PMMA denture. However, the influence of such particles was more pronounced on enhancing mode I fracture toughness (K_Ic) value. Pure mode II fracture toughness value was obtained less than the pure mode I fracture toughness in the tested specimen showing the higher crack growth risk of such PMMA base dentures against dominantly shear loads. The well-known maximum tangential stress theory was also used for estimating the obtained experimental data both for mixed mode fracture toughness and fracture initiation direction in the tested PMMA base denture materials.

Tapered vs. Uniform Tube-Load Modeling of Blood Pressure Wave Propagation in Human Aorta

In this paper, tapered vs. uniform tube-load models are comparatively investigated as mathematical representation for blood pressure (BP) wave propagation in human aorta. The relationship between the aortic inlet and outlet BP waves was formulated based on the exponentially tapered and uniform tube-load models. Then, the validity of the two tube-load models was comparatively investigated by fitting them to the experimental aortic and femoral BP waveform signals collected from 13 coronary artery bypass graft surgery patients. The two tube-load models showed comparable goodness of fit: (i) the root-mean-squared error (RMSE) was 3.3+/−1.1 mmHg in the tapered tube-load model and 3.4+/−1.1 mmHg in the uniform tube-load model; and (ii) the correlation was r = 0.98+/−0.02 in the tapered tube-load model and r = 0.98+/−0.01 mmHg in the uniform tube-load model. They also exhibited frequency responses comparable to the non-parametric frequency response derived from the aortic and femoral BP waveforms in most patients. Hence, the uniform tube-load model was superior to its tapered counterpart in terms of the Akaike Information Criterion (AIC). In general, the tapered tube-load model yielded the degree of tapering smaller than what is physiologically relevant: the aortic inlet-outlet radius ratio was estimated as 1.5 on the average, which was smaller than the anatomically plausible typical radius ratio of 3.5 between the ascending aorta and femoral artery. When the tapering ratio was restricted to the vicinity of the anatomically plausible typical value, the exponentially tapered tube-load model tended to underperform the uniform tube-load model (RMSE: 3.9+/−1.1 mmHg; r = 0.97+/−0.02). It was concluded that the uniform tube-load model may be more robust and thus preferred as the representation for BP wave propagation in human aorta; compared to the uniform tube-load model, the exponentially tapered tube-load model may not provide valid physiological insight on the aortic tapering, and its efficacy on the goodness of fit may be only marginal.

Data mining investigation of the association between a limb ballistocardiogram and blood pressure

OBJECTIVE

To investigate the association between a limb ballistocardiogram (BCG) and blood pressure (BP) based on data mining.

APPROACH

During four BP-perturbing interventions, the BCG and reference BP were measured from 23 young, healthy volunteers using a custom-manufactured wristband equipped with a MEMS accelerometer and a commercial continuous BP measurement device. Both timing and amplitude features in the wrist BCG waveform were extracted, and significant features predictive of diastolic (DP) and systolic (SP) BP were selected using stepwise linear regression analysis. The selected features were further compressed using principal component analysis to yield a small set of DP and SP predictors. The association between the predictors thus obtained and BP was investigated by multivariate linear regression analysis.

MAIN RESULTS

The predictors exhibited a meaningful association with BP. When three most significant predictors were used for DP and SP, a correlation coefficient of r  =  0.75  ±  0.03 (DP) and r  =  0.75  ±  0.03 (SP), a root-mean-squared error (RMSE) of 7.4  ±  0.6 mmHg (DP) and 10.3  ±  0.8 mmHg (SP), and a mean absolute error (MAE) of 6.0  ±  0.5 mmHg (DP) and 8.3  ±  0.7 mmHg (SP) were obtained across all interventions (mean  ±  SE). The association was consistent in all the individual interventions (r  ⩾  0.68, RMSE  ⩽  5.7 mmHg, and MAE  ⩽  4.5 mmHg for DP as well as r  ⩾  0.61, RMSE  ⩽  7.9 mmHg, and MAE  ⩽  6.4 mmHg for SP on the average). The minimum number of requisite predictors for robust yet practically realistic BP monitoring appeared to be three. The association between predictors and BP was maintained even under regularized calibration (r  =  0.63  ±  0.05, RMSE  =  9.3  ±  0.8 mmHg, and MAE  =  7.6  ±  0.7 mmHg for DP as well as r  =  0.60  ±  0.05, RMSE  =  14.7  ±  1.4 mmHg, and MAE  =  11.9  ±  1.1 mmHg for SP (mean  ±  SE)). The requisite predictors for DP and SP were distinct from each other.

SIGNIFICANCE

The results of this study may provide a viable basis for ultra-convenient BP monitoring based on a limb BCG alone.

Placental site trophoblastic tumor, report of a case with unusual presentation

Placental site trophoblastic tumor (PSTT) is the rarest type of gestational trophoblastic tumors. Common presentation is irregular vaginal bleeding. A 26-year-old G1P1 woman presented with 15 month amenorrhea, a large uterine mass and plateau low level of serum human chorionic gonadotropin (hCG) which raised the possibility of PSTT. Since whole myometrium had been substituted with the large tumoral mass, hysterectomy was considered despite the young age of the patient. The patient has been in remission 36 months postoperatively without receiving any adjuvant treatment. It seems that plateau low levels of hCG in the presence of amenorrhea should prompt the possibility of PSTT.

Preliminary studies on allelopatic effect of some woody plants on seed germination of rye-grass and tall fescue

In order to investigation of allelopathic effects of some ornamental trees on seed germination of rye-grass (Lolium prenne) and tall fescue (Festuca arundinaceae), this experiment was conducted in a randomized complete block design with 3 replicates at the laboratory of Horticultural Sciences Department of Ferdowsi University of Mashhad, during 2008. In this research, we studied the effect of aqueous and hydro-alcoholic extracts of Afghanistan pine (Pinus eldarica), arizona cypress (Cupressus arizonica), black locust (Robinia psedue acacia) and box elder (Acer negundo) leaves that prepared in 1:5 ratio on seed germination percent and rate for two grasses. The results showed that all extracts decreased statistically seed germination in compared to control treatment. The highest germination percentage and germination rate of tested grass detected in control treatment. Hydro-alcoholic extracts of all woody plants (15, 30%) were completely inhibited seed germination of rye-grass and tall fescue. Also aqueous extract of arizona cypress was completely inhibited seed germination of tall fescue and had more inhibitory activity than other aqueous extracts on rye-grass. Between aqueous extracts, the highest and lowest seed germination of rye-grass was found in Afghanistan pine and arizona cypress, respectively.

Effect of integrated bombardment and Agrobacterium transformation system on transient GUS expression in hypocotyls of rapeseed (Brassica napus L. cv. PF704) microspore-derived embryos

A new method for transformation of rapeseed microspore-derived embryos (MDEs), based on microwounding of MDEs by particle bombardment prior to inoculation with an Agrobacterium suspension was reported. In this study, effects of two transformation systems (integrated bombardment and Agrobacterium transformation system and the singular bombardment) on transient GUS expression in hypocotyls of rapeseed (Brassica napus L. cv. PF704) MDEs were studied. Bombardment parameters were: helium pressure, 1350 psi; distance between stopping screen and target tissue, 9 cm, gold particles size of 1.0 microm and chamber vacuum pressure, 24 in Hg. In integrated system A. tumefaciens strain AGL1 carrying the binary vector pCAMBIA3301 was used. Bombarded hypocotyls of MDEs were inoculated with Agrobacteria at OD600 = 1.0 for 10 min or OD600 = 0.25 for 24 h. Integrated transformation system increased the mean number of blue spots about 2-2.5 fold compared to singular bombardment and inoculated hypocotyls with OD600 = 1.0 for 10 min produced the highest number of blue spots per bombardment (743 +/- 23.67).

Neoadjuvant chemotherapy and radical surgery compared to radical surgery alone in bulky stage IB-IIA cervical cancer

AIM

The aim of this study was evaluation of the efficacy of neoadjuvant chemotherapy (NACT) and radical hysterectomy on long-term survival in stage IB-IIA locally advanced cervical cancer as compared with radical surgery alone.

METHODS

We reviewed all patients with cervical cancer stage IB-IIA who were treated with two treatment modalities, i.e. NACT followed by radical hysterectomy and lymphadenectomy, and radical hysterectomy alone between March 1996 and March 2004. There were 22 patients in the NACT group (group 1) and 160 patients in the immediate radical surgery group (group 2). All patients in group 1 were followed for more than 108months, and long-term survival and factors affecting recurrence were evaluated.

RESULTS

Nineteen patients in the NACT arm underwent radical surgery. Pelvic lymph node metastasis was found in 8 patients in this group and in 36 in the radical surgery group. Eighteen patients in the NACT group and 96 patients in the radical surgery group were scheduled for adjuvant postoperative chemoradiation. During the 9-year follow-up, recurrence rate was 47.1% and 30.2% in NACT and control groups, respectively. In the NACT group lymph node metastasis was a significant independent risk factor for recurrence. Overall survival in the NACT arm was not statistically significantly lower than the control arm (p=0.06).

CONCLUSION

NACT did not improve long-term overall survival of bulky early-stage cervical cancer patients compared to primary radical surgery.

Cyclosporin A and mini short-term methotrexate vs cyclosporin A as graft-versus-host disease prophylaxis in patients with beta thalassemia major undergoing allogeneic blood and marrow transplantation

We compared the effects of cyclosporin A (CsA) alone as graft-versus-host disease (GVHD) prophylaxis vs cyclosporine with short-course methotrexate (MTX) in patients with thalassemia. In all, 140 patients were enrolled in this study. The first group, of 50 patients, received CsA alone at 3 mg/kg i.v. from day -2 to +5 followed by 12.5 mg/kg p.o., which was tapered according to the patient's condition. The other group, of 90 patients, received the combination of CsA+MTX in which CsA was used with the above-mentioned dose and MTX was on 10 mg/m(2) day +1 and 6 mg/m(2) on days +3 and +6. Incidence of acute GVHD grade II-IV in the CsA group was 78% and in the CsA+MTX group was 52.2%, which was statistically significant (P=<0.001). There were no significant differences in the incidence of chronic GVHD between the two groups. The mean neutrophil engraftment to 0.5 x 10(9)/l was 14 and 23 days for CsA group and CsA+MTX group, respectively (P=<0.001). There were no significant differences for platelet recovery between the two groups. Graft failure in the CsA and CsA+MTX groups was seven (14%) and nine (10%) patients, respectively (P=0.58). Overall survival in the CsA and CsA+MTX groups was 77 and 85%, respectively. Disease-free survival in the CsA and CsA+MTX groups were 58 and 80%, respectively.

Comparative study of chemoradiation and neoadjuvant chemotherapy effects before radical hysterectomy in stage IB?IIB bulky cervical cancer and with tumor diameter greater than 4 cm

Tumor size seems to be a determinant in the prognosis of early cervical cancer. Patients with tumor greater than 4 cm (bulky) in diameter have worse outcome. The purpose of this study was to compare the efficacy of preoperative combined chemoradiation and neoadjuvant chemotherapy (NAIC) programs followed by radical hysterectomy in stage IB-IIB bulky cervical cancer. From September 1999 to April 2002, 60 patients with stage IB-IIB bulky cervical cancer were treated with preoperative external-beam radiotherapy to 45 Gy plus weekly cisplatin 50 mg/m2 or preoperative NAIC by cisplatin 50 mg/m2 and vincristin 1 mg/m2 every 7-10 days, for three courses. Surgery was performed 4-6 weeks after the completion of the preoperative treatment. There were no significant difference between age, stage, tumor size, and histopathologic type in two groups (P > 0.05). Toxicity associated with two treatment methods was usually mild. In chemoradiation group, two patients developed vesicovaginal fistula, and four patients developed long-term hydronephrosis that needed urethral stenting. Before surgery, complete and partial clinical response had no significant difference between two groups (P > 0.05). After surgery, lymph node and parametrial involvement had no significant difference between two groups (P > 0.05). In NAIC group, more patients had significantly residual tumor (P = 0.012), but residual tumor size had no significant difference between two groups (P > 0.05). Pathologic complete response was significantly higher in chemoradiation group (P = 0.004). According to the result of this study, it seems that NAIC and chemoradiation had similar effects in survival prognostic factors.

Comparative study of chemoradiation and neoadjuvant chemotherapy effects before radical hysterectomy in stage IB–IIB bulky cervical cancer and with tumor diameter greater than 4 cm

Tumor size seems to be a determinant in the prognosis of early cervical cancer. Patients with tumor greater than 4 cm (bulky) in diameter have worse outcome. The purpose of this study was to compare the efficacy of preoperative combined chemoradiation and neoadjuvant chemotherapy (NAIC) programs followed by radical hysterectomy in stage IB–IIB bulky cervical cancer. From September 1999 to April 2002, 60 patients with stage IB–IIB bulky cervical cancer were treated with preoperative external-beam radiotherapy to 45 Gy plus weekly cisplatin 50 mg/m2 or preoperative NAIC by cisplatin 50 mg/m2 and vincristin 1 mg/m2 every 7–10 days, for three courses. Surgery was performed 4–6 weeks after the completion of the preoperative treatment. There were no significant difference between age, stage, tumor size, and histopathologic type in two groups (P > 0.05). Toxicity associated with two treatment methods was usually mild. In chemoradiation group, two patients developed vesicovaginal fistula, and four patients developed long-term hydronephrosis that needed urethral stenting. Before surgery, complete and partial clinical response had no significant difference between two groups (P > 0.05). After surgery, lymph node and parametrial involvement had no significant difference between two groups (P > 0.05). In NAIC group, more patients had significantly residual tumor (P = 0.012), but residual tumor size had no significant difference between two groups (P > 0.05). Pathologic complete response was significantly higher in chemoradiation group (P = 0.004). According to the result of this study, it seems that NAIC and chemoradiation had similar effects in survival prognostic factors.

Is normal beta-hCG regression curve helpful in the diagnosis of persistent trophoblastic disease?

OBJECTIVE

The aim of this study was to evaluate the probable usefulness of normal beta-human chorionic gonadotropin (beta-hCG) regression curve in the diagnosis of persistent trophoblastic disease (PTD).

METHODS

A log-value regression curve was developed from the means and 95% confidence limits of serial weekly serum beta-hCG titers of 43 patients with uneventful complete hydatidiform moles and 14 patients, who were previously confirmed as PTD.

RESULTS

All 14 PTD patients (100%) had abnormal values, beyond normal range, within 4 weeks. beta-hCG was in its upper values, compared to normal regression curve at 2.29 +/- 0.19 weeks. This was earlier than plateau or rise detection at 4.21 +/- 0.33 weeks (P < 0.001). Within 3 weeks of evacuation, 13 of 14 (92.86%) PTD patients' beta-hCG values exceeded the normal range, whereas only six of 14 (42%) showed a rise or plateau.

CONCLUSION

Our finding indicates that the normal beta-hCG regression curve may be useful for quicker detection of PTD than the plateau or rise of level.

Visual inspection with acetic acid as a feasible screening test for cervical neoplasia in Iran

The aim of this study was to estimate the sensitivity and specificity of visual inspection of the uterine cervix with acetic acid (VIA) as a screening test for cervical carcinoma and its precursors. One thousand and two hundred eligible women were screened by VIA and Papanicolaou smear. Those positive on one or both of these screening tests (n = 308) or those who had clinically suspicious lesions, even if the tests were negative [25% of remainders (n = 290)], were referred for colposcopy. Three hundred and fifty five of 598 women at colposcopy underwent biopsies or endocervical curettage. Those with cervical intraepithelial neoplasia I (CIN I) or worse lesions, diagnosed by histology, were considered true positive. VIA was positive in 191 women (16.1%). In 175 true-positive cases, VIA detected 130 cases, yielding a sensitivity of 74.3% and a specificity of 94%. By considering atypical squamous cell of undetermined significance or worse lesions on Papanicolaou smear as referring threshold for colposcopy, the sensitivity and specificity of cytology were 72 and 90.2%, respectively. In conclusion, the sensitivity and specificity of VIA is high and comparable with that of cytology. Hence, VIA can be undertaken as a feasible method of screening in cervical cancer in countries where access to cytopathology is limited.

Is normal β-hCG regression curve helpful in the diagnosis of persistent trophoblastic disease?

Objective

The aim of this study was to evaluate the probable usefulness of normal β-human chorionic gonadotropin (β-hCG) regression curve in the diagnosis of persistent trophoblastic disease (PTD).

Methods

A log-value regression curve was developed from the means and 95% confidence limits of serial weekly serum β-hCG titers of 43 patients with uneventful complete hydatidiform moles and 14 patients, who were previously confirmed as PTD.

Results

All 14 PTD patients (100%) had abnormal values, beyond normal range, within 4 weeks. β-hCG was in its upper values, compared to normal regression curve at 2.29 ± 0.19 weeks. This was earlier than plateau or rise detection at 4.21 ± 0.33 weeks (P < 0.001). Within 3 weeks of evacuation, 13 of 14 (92.86%) PTD patients' β-hCG values exceeded the normal range, whereas only six of 14 (42%) showed a rise or plateau.

Conclusion

Our finding indicates that the normal β-hCG regression curve may be useful for quicker detection of PTD than the plateau or rise of level.

Simple hysterectomy in the presence of invasive cervical cancer in Iran

The objective of this study was to determine the reasons leading to an inappropriate simple hysterectomy in the presence of invasive cervical cancer. During 1997-2001, 62 cases of invasive cervical carcinoma that had been treated by simple hysterectomy were referred to the gynecology oncology service in Vali-e-Asr hospital, Tehran, Iran. Five had microinvasive carcinoma. The remaining 57 women had either adenocarcinomas or squamous cell carcinoma (SCC). Medical records were reviewed retrospectively to determine the reasons for inappropriate hysterectomy. Reasons for inappropriate hysterectomy were as follow: lack of preoperative Pap smear (P/S) (29%), deliberate hysterectomy for biopsy-proven cancer (25.8%), negative P/S (6.5%), inadequate evaluation of abnormal P/S (6.5%), failure to perform an indicated conization (3.2%), and emergent operation because of uterine perforation (1.6%). Reasons for inappropriate hysterectomy in the remainder of patients (27.4%) were not found because of lack of sufficient information. Although 45.2% of these patients had complained for vaginal bleeding, only four of them had preoperative endocervical and endometrial sampling. Despite the increasing emphasis on performing cervical cancer screening before hysterectomy, only 18 (29%) referral patients had preoperative P/S. We conclude that by close adherence to the cervical cancer screening guidelines and appropriate evaluation of the presenting symptoms, we may avoid inappropriate management of cervical carcinomas with simple hysterectomy. Many cases of simple hysterectomy in the presence of biopsy-proven squamous cell carcinoma of the cervix necessitates some reconsideration of gynecology oncology postgraduate courses for general gynecologists.

Simple hysterectomy in the presence of invasive cervical cancer in Iran

The objective of this study was to determine the reasons leading to an inappropriate simple hysterectomy in the presence of invasive cervical cancer. During 1997–2001, 62 cases of invasive cervical carcinoma that had been treated by simple hysterectomy were referred to the gynecology oncology service in Vali-e-Asr hospital, Tehran, Iran. Five had microinvasive carcinoma. The remaining 57 women had either adenocarcinomas or squamous cell carcinoma (SCC). Medical records were reviewed retrospectively to determine the reasons for inappropriate hysterectomy. Reasons for inappropriate hysterectomy were as follow: lack of preoperative Pap smear (P/S) (29%), deliberate hysterectomy for biopsy-proven cancer (25.8%), negative P/S (6.5%), inadequate evaluation of abnormal P/S (6.5%), failure to perform an indicated conization (3.2%), and emergent operation because of uterine perforation (1.6%). Reasons for inappropriate hysterectomy in the remainder of patients (27.4%) were not found because of lack of sufficient information. Although 45.2% of these patients had complained for vaginal bleeding, only four of them had preoperative endocervical and endometrial sampling. Despite the increasing emphasis on performing cervical cancer screening before hysterectomy, only 18 (29%) referral patients had preoperative P/S. We conclude that by close adherence to the cervical cancer screening guidelines and appropriate evaluation of the presenting symptoms, we may avoid inappropriate management of cervical carcinomas with simple hysterectomy. Many cases of simple hysterectomy in the presence of biopsy-proven squamous cell carcinoma of the cervix necessitates some reconsideration of gynecology oncology postgraduate courses for general gynecologists.

A novel glycine-rich protein is associated with starch grain accumulation during anther development

LIM14, originally identified as a lily gene associated with microsporogenesis, encodes a protein which has two distinct domains, one with glycine-serine repeats and the other with a hydrophobic signal peptide at the N-terminus. The putative LIM14 protein, however, is distinct from the glycine-rich cell wall proteins which have been described before. RNA analyses indicated that the LIM14 transcript is specifically detected in the anther from zygotene to young pollen stage. By using antibodies raised against recombinant LIM14 protein, we detected anther-specific 15 kDa protein. Immunofluorescence microscopy demonstrated that the LIM14 protein is associated with starch grains in the anther wall cells just prior to microspore mitosis and then accumulates at a higher level with the starch grains of immature pollen. We tagged LIM14 with the GUS and GFP reporter genes and introduced them into tobacco BY-2 cells. Analysis of the transformed cells revealed that the chimeric proteins are functional and specifically targeted to plastids. These results indicate that LIM14 is an anther-specific protein that may play a role in starch accumulation and amyloplast differentiation during anther development and pollen formation.

Extravasation of contrast material from vascular ectasia of the cecum detected with 99mTc-pertechnetate

A case of vascular ectasia of the cecum is presented. The isotopic pattern did not differ from that of Meckel's diverticulum. The authors suggest that studies with 99mTc may be helpful in screening for areas of pathology in cases of lower gastrointestinal bleeding.