The miR-644a/CTBP1/p53 axis suppresses drug resistance by simultaneous inhibition of cell survival and epithelial-mesenchymal transition in breast cancer

Tumor cells develop drug resistance which leads to recurrence and distant metastasis. MicroRNAs are key regulators of tumor pathogenesis; however, little is known whether they can sensitize cells and block metastasis simultaneously. Here, we report miR-644a as a novel inhibitor of both cell survival and EMT whereby acting as pleiotropic therapy-sensitizer in breast cancer. We showed that both miR-644a expression and its gene signature are associated with tumor progression and distant metastasis-free survival. Mechanistically, miR-644a directly targets the transcriptional co-repressor C-Terminal Binding Protein 1 (CTBP1) whose knock-outs by the CRISPR-Cas9 system inhibit tumor growth, metastasis, and drug resistance, mimicking the phenotypes induced by miR-644a. Furthermore, downregulation of CTBP1 by miR-644a upregulates wild type- or mutant-p53 which acts as a 'molecular switch' between G1-arrest and apoptosis by inducing cyclin-dependent kinase inhibitor 1 (p21, CDKN1A, CIP1) or pro-apoptotic phorbol-12-myristate-13-acetate-induced protein 1 (Noxa, PMAIP1), respectively. Interestingly, an increase in mutant-p53 by either overexpression of miR-644a or downregulation of CTBP1 was enough to shift this balance in favor of apoptosis through upregulation of Noxa. Notably, p53-mutant patients, but not p53-wild type ones, with high CTBP1 have a shorter survival suggesting that CTBP1 could be a potential prognostic factor for breast cancer patients with p53 mutations. Overall, re-activation of the miR-644a/CTBP1/p53 axis may represent a new strategy for overcoming both therapy resistance and metastasis.

Metastasis of prostate adenocarcinoma to the frontal and ethmoid sinus

Intracranial metastasis of prostate cancer is rarely seen, and there are few studies in this regard in the literature. Most of these studies in the literature comprise the metastasis of prostate cancer to the sphenoid sinus, and metastasis to the frontal and ethmoid sinus is a much rare entity. Association of visual symptoms, epistaxis, headache, and hematuria may indicate a urologic malignancy in terms of the origin of the primary tumor. This study was aimed to present the prostate cancer case of a 73-year-old patient whose paranasal sinus tomograms revealed the presence of frontal and ethmoid sinus metastasis.

Skin punch biopsy sectioning: before or after tissue processing?

BACKGROUND

We intended to study whether there is a meaningful difference in microscopic examination between dividing a biopsy section into two equal parts before tissue processing (first method) or after (second method).

METHODS

A total of 400 cases were included in the study. Punch biopsies (PB) were cut into two pieces using the first method in 200 cases and just before paraffin embedding in another 200 cases using the second method. We microscopically evaluated the epidermal mesh view, the presence of a cross-cut hair follicle and bow shape because of epidermal angling, the presence of two pieces on the slide and if there was a difference of >2 mm between the parts, and the number of new sections and new slides.

RESULTS

Cross-cut hair follicle (p = 0.018), epidermal mesh view (p = 0.036), difference of >2 mm between the parts (p = 0.008), the number of new sections (p < 0.001) and new slides (p < 0.001) were considerably higher when the first method was used compared with the second method. The presence of two pieces was less (p < 0.001) when using the first method.

CONCLUSIONS

We noted a meaningful difference in the quality of microscopic evaluation between the first and second methods. Better sections were obtained with the second method. In addition, the decrease in the number of new slides will reduce workload, archival work and cost.

Retrospective analysis of oncogenic human papilloma virus and Epstein-Barr virus prevalence in Turkish nasopharyngeal cancer patients

Nasopharyngeal carcinoma (NPC) is associated with the Epstein-Barr virus (EBV). Human papilloma virus (HPV) has also been detected in NPC cases. In this retrospective study, we analyze the frequency of EBV and HPV infection in 82 Turkish patients with NPC. A total of 82 were evaluated for EBV and HPV. In situ hybridization (ISH) was performed for EBV. HPV-ISH and P16 immunohistochemistry used to determine the HPV status. Seventy-two of the 82 (87%) NPC patients were EBV-positive. The highest rate of EBV-positivity was found in undifferentiated NPC patients, which accounted for 65 of 68 (95.6%) undifferentiated cases. One of the 82 NPC patients whose tumor was non-keratinizing differentiated, contained HPV. Our data shows that EBV is closely associated with NPC in Turkey. We found lower rates of HPV-positivity in NPC patients than in North American populations. In addition, both EBV and HPV-negativity were more associated with decreased survival than EBV-positive cases.

Histopathological findings obtained from reduction mammoplasty specimens

BACKGROUND/AIM

Reduction mammoplasty is a common surgical procedure. We report the incidence of nonproliferative and proliferative breast lesions in breast reduction specimens from a single institution over a 6-year period.

MATERIALS AND METHODS

The histopathology reports of all patients were analyzed. The clinical and histopathological findings of the patients were recorded.

RESULTS

Between 2004 and 2010, 106 patients underwent breast reduction. Fifty-six patients (52.8%) had proliferative breast lesions, 84 patients (79.2%) had nonproliferative lesions, 8 patients (7.5%) had columnar cell lesions without atypia, 61 patients (57.5%) had columnar cell lesions with atypia, 5 patients (4.7%) had atypical ductal hyperplasia, and 6 patients (5.6%) had lobular carcinoma in situ. No invasive breast cancer was identified.

CONCLUSION

In Turkey, there is limited evidence regarding the role of histopathological analysis in reduction mammoplasty. Moreover, none of the previous studies determined columnar cell lesion rates in reduction mammoplasty patients. The detection of significantly elevated columnar cell lesions, with or without atypia, especially in patients under the age of 40, increases the importance of screening tests, especially in Turkey, which has a high incidence of breast cancer in early ages, and addresses the need to starting screening tests early in these patients.

The role of collecting bladder wash fluid before biopsy procedure to help the cytological diagnosis of residual tumor

BACKGROUND

Urinary cytology has low sensitivity and specificity in urinary neoplasm.

AIM

We planned to assess whether the examination of bladder washing before biopsy (WBB) plays a role in better cytologic diagnosis of bladder wash fluid collected after biopsy procedure (WAB) in papillary urothelial neoplasms.

MATERIALS AND METHODS

We included 36 patients with papillary lesion of bladder. Prior to the biopsy, the bladder is washed and fluid is collected for cytology; later transurethral resection (TUR) is performed, then bladders are washed again and the fluid is separately collected for cytology. Both fluids were centrifuged and stained with May-Grünwald Giemsa (MGG). First the WAB slides were evaluated and diagnosed. After evaluation of the WBB slides, the WAB slides were rediagnosed. Presence of cellularity, papillary structure, fusiform cells, background bleeding, and cytolysis in WBB and WAB were evaluated separately.

RESULTS

We determined that 31 WBB samples were hypercellular, and 12 of them remained as hypercellular in WAB. Papillary structures were observed in 20 WBB samples; and in one WAB cytology. In 29 cases where no fusiform cells are identified in WBB, 22 showed fusiform cells in WAB. Cytolysis in WABs was noted in 15 cases whose WBBs did not show cytolysis. The decrease in cellularity, papillary structure (P < 0.001, both), cytolysis (P = 0.008), and fusiform cells (P < 0.001) were statistically significant. After seeing the WBB slides, we reevaluated the WAB slides. Out of the eight out of 36 (22.2%) samples diagnosed with degeneration previously, five (62.5%) samples were rediagnosed as benign, two (25%) as cytologic atypia which favor reactive, and one (12.5%) as malignant.

CONCLUSION

Due to the better quality, initial evaluation of WBB may help more effective diagnoses of WAB slides.

A retrospective analysis of prognostic factors predictive of lymph-node metastasis and recurrence in thyroid papillary microcarcinoma

AIM

The literature is inconclusive concerning the prognostic factors and therapeutic management of papillary thyroid microcarcinoma (PTMC). Herein we report on our extensive experience with PTMC in relation to clinicopathological characteristics and prognostic factors.

METHODS

In all, 248 patients that were diagnosed and treated for PTMC between 2007 and 2012 were retrospectively analyzed. Demographic and tumor characteristics at presentation, and recurrence during follow-up were noted.

RESULTS

Total thyroidectomy and radioactive iodine (RAI) ablation treatment were performed in all patients. Bilateral involvement, vascular and capsular invasion, extra-thyroidal extension, and lymph node metastasis occurred significantly more frequently in patients with tumor size>5 mm (P<0.05). Multivariate statistical analysis showed that a clinically suspected diagnosis (OR:0.095; P=0.043) and elevated thyroglobulin (TG) level (OR: 1.083; P=0.011; cut-off value≥7.98 ngmL(-1)) were significant and independent risk factors for lymph node metastasis, with a sensitivity of 57% and specificity of 83%. After a median follow-up of 2 years (range:0.3-11 years), 10 (4%) of the 248 patients had recurrent disease. According to multivariate analysis, lymph node metastasis (OR: 51.4; P=0.003) was the only independent predictor of recurrence.

CONCLUSION

Our findings revealed that serum TG level and a clinically suspected diagnosis were risk factors for lymph node metastasis, while nodal metastasis was a predictor of recurrence.

Correlation of thyroid fine-needle aspiration with final histopathology: a case series

AIM

The aim of this study was to evaluate the correlation between preoperative thyroid fine-needle aspiration result and final histopathology in patients with thyroid nodules.

METHODS

The medical records of 298 patients (mean age, 47.7±12.3 years; 79.5% females) who underwent fine-needle aspiration for thyroid nodules and who were operated and have final pathological diagnosis were retrospectively reviewed. For reporting fine-needle aspiration specimen pathology, the Bethesda thyroid fine-needle aspiration classification was used. Tyroglobulin (Tg) and anti-Tg and anti-thyroid peroxidase (anti-TPO) antibody levels were determined preoperatively.

RESULTS

Thyroid nodules were non-diagnostic, benign or atypia (Bethesda groups 1-3) in 76.8% of patients; and follicular neoplasm, suspicious for malignancy or malignant (Bethesda groups 4-6) in 23.1% of patients. Final pathology of surgery specimen was most commonly nodular goiter (36.6%) and papillary carcinoma (35.6%). Nodular goiter was significantly more prevalent in Bethesda 1 group while papillary carcinoma was more common in Bethesda 3 group (P<0.05). Tg level is significantly higher in the nodular goiter group (90.49±126.93 ng/mL), while anti-Tg and anti-TPO levels are significantly higher in the lymphocytic thyroiditis goiter group (229.77±494.42 U/mL and 282.86±360.77 U/mL, respectively) than the other pathology groups (P<0.05 for all).

CONCLUSION

Papillary carcinoma is more common in Bethesda thyroid fine-needle aspiration classification 3 group. Therefore, preoperative fine-needle aspiration for thyroid nodules is predictive of final pathology and should be applied for diagnosis and follow-up.

Diagnostic value of elastosonographically determined strain index in the differential diagnosis of benign and malignant thyroid nodules

Elastosonography (ES) is a newly developed method that is used for the differential diagnosis of benign and malignant thyroid nodules. In different studies, ES scoring has been compared with histopathological findings, and sensitivity and specificity of the scoring were calculated. In this study, it determines the strain index (SI) as well as the ES to score thyroid nodules, and establishes the role for these parameters in the differential diagnosis of thyroid nodules using histopathological analysis as a reference standard. Real-time ES in transverse axis (TA) and longitudinal axis (LA) was performed in 391 nodules of 292 patients. ES scoring was made for all the nodules. SI in TA and LA was calculated for four times in each nodule and mean values were determined. The results were compared with final histopathological diagnoses. In histopathological examinations, 125 (31.97%) of 391 nodules were malignant and 266 (68.03%) were benign. Of these histopathologically benign nodules, 189 (%71.05) were also probably benign according to elastosonographic scoring (scores of 1, 2, or 3), while 77 (28.95%) were probably malignant (scores of 4 or 5). Among 125 histopathologically malignant nodules, 52 (41.60%) were probably benign and 73 (58.40%) were probably malignant according to elastosonographic scoring. There was a significant relation between scoring and histopathological findings (χ(2) = 36.513; P < 0.001). Accordingly, sensitivity and specificity of ES scoring were 58.4 and 71.0%, respectively. ROC analysis value obtained for strain ratios in LA (AUC: 75.5%; P < 0.001) had a higher significance compared to ROC analysis value obtained for strain ratios in TA (AUC: 66.0%). Thus, ROC analysis evaluation was applied only for SI in LA. The optimal SI cut-off value in LA for all the nodules was found to be 16.709 (sensitivity: 73.4%, specificity: 70.0%) (AUC: 75.4 ± 0.03%; 70.2-80.5%). SI cut-off value corresponding to 90% sensitivity in this axis was 4.516 (specificity: 35.7%). Sensitivity and specificity of SI values that were determined according to morphological features of nodules in gray-scale ultrasonography were higher. For hypoechoic nodules with microcalcifications and without a halo, SI cut-off value, sensitivity, and specificity were 17.020, 84.3, and 81.1%, respectively. Our study is the first clinical-wide series study that measured, used, and compared the ES scoring and SI cut-off values for the differential diagnosis of benign and malignant thyroid nodules. This study indicates that measurement of SI with ES as a noninvasive procedure may be used as an adjunctive method to the conventional methods for the differential diagnosis of thyroid nodules.

Primary orbital endodermal sinus tumor (yolk sac tumor)

Endodermal sinus tumor, or yolk sac tumor, is the most common malignant neoplasm of germ cell origin and usually occurs in infant testes or ovaries. On rare occasions, the tumor may arise from extragonadal sites, including sacrococcygeal region, uterus, vagina, prostate, retroperitoneum, liver, mediastinum, pineal gland, and third ventricle. The orbit is an unusual location for the primary development of this neoplasm. We report the case of a girl with primary orbital endodermal sinus tumor who was managed with exenteration and chemotherapy with the result of a disease-free survival of 9 years.

Atypical teratoid/rhabdoid tumors: imaging findings of two cases and review of the literature

Atypical teratoid/rhabdoid tumor (AT/RT) is a malignant embryonal central nervous system (CNS) tumor, manifesting in children, and composed of rhabdoid cells, with or without fields resembling a classical primitive neuroectodermal tumor (PNET), epithelial tissue and neoplastic mesenchyme. Around 200 cases of CNS AT/RT have been documented in the literature. Although the clinical and pathological findings have been defined in large series previously, and AT/RT has become increasingly recognized, awareness of typical AT/RT is important in making the correct diagnosis of this uncommon but probably underdiagnosed entity. Neuroradiologists rarely mention AT/RT in their differential diagnosis and this paper presents two additional cases in which clinical and pathological findings are combined with neuroradiological presentation.

Effects of static and 50 Hz alternating electric fields on superoxide dismutase activity and TBARS levels in guinea pigs

The toxic oxygen free radicals are extremely reactive and can cause considerable damage to biomolecules, such as RNA, enzymes, membranes, proteins, and lipids, which may in turn lead to various pathological consequences. Lipid peroxidation, evaluated by determination of thiobarbituric acid reactive substances (TBARS) is the free radical-induced oxidation of polyunsaturated fatty acids. Normally, the oxygen free radicals are neutralized by highly efficient systems in the body. These include antioxidant enzymes like superoxide dismutase (SOD). In a healthy subject, there is a balance between free radicals and levels of antioxidants. The aim of this study was to determine lipid peroxidation and SOD levels in plasma, liver, lung and kidney tissues exposed to different intensities, directions and exposure periods of static and 50 Hz alternating electric fields. Electric field intensities ranging from 0.3 kV/m to 1.8 kV/m were applied in vertical or horizontal direction in exposure periods of 1, 3, 5, 7, and 10 days. The increase in SOD and TBARS levels of plasma, liver, lung, and kidney tissues was found to depend significantly on the type of electric field and the exposure period.

Expression of PTEN, cyclin D1, P27/KIP1 in invasive ductal carcinomas of the breast and correlation with clinicopathological parameters

In this study, tumour tissue samples of 85 primary breast cancer patients were evaluated for phosphatase and tensin homolog deleted on chromosome ten (PTEN), cyclin D1 and P27/Kip1 expression patterns. The results were correlated with clinicopathological parameters. Loss of PTEN protein expression was present in 32.5% of the cases. Cyclin D1 was overexpressed in 54.2% and P27/Kip1 in 89.3% of the cases. Statistically significant associations were found between PTEN and cyclin D1 expression patterns, and cyclin D1 expression and tumour size.

Expression of hepatocyte growth factor/scatter factor receptor in IUGR fetuses' placentas: an immunohistochemical analysis

OBJECTIVE

We aimed to evaluate the expression sta tus of c-met, receptor for the hepatocyte growth factor (HGF), in the placentas of intrauterine growth retardation (IUGR) fetuses.

MATERIALS AND METHODS

Placentas were obtained during delivery from both third trimester normal and IUGR complicated pregnancies. Ultrasonographic estimation of fetal birth weight has been done and placentas of those under the fifth percentile for their gestational ages were enrolled in the study group. Eighteen fetuses with IUGR and 6 uncomplicated pregnancies were subjected to the study. Histological sections from placentas were immunohistochemically evaluated for the expression status of c-met.

RESULTS

Seventeen of the eighteen patients (94.4%) in the study group were found to have overexpression of the c-met while this figure was only 16.7% (1/6) in the control group (p < 0.0001). There was a strong statistically significant difference between the two groups regarding degree of c-met expression.

CONCLUSION

Our present findings suggest that c-met is an important cell membrane receptor in human placenta. Deregulation of the interaction between HGF and its receptor c-met during placentation may be the cause responsible for the growth retardation of the fetus due to the impaired placental functions.

High-Grade Neuroendocrine Carcinoma of the Cervix

Neuroendocrine tumor of the uterine cervix is a rare and aggressive malignancy. Despite controversial, multimodal treatment methods, prognosis and treatment outcomes are worst in advanced stages. We report an early-stage case treated with the multimodal approach. The nomenclature proposed for this tumor type in 1997 by the College of American Pathologists still has some points of discussion. As in our case some of the tumors cannot be defined exactly into small or large cell types, and this causes confusion at least for nomenclature purposes. A 'mixed' type for this tumor may be appropriate.

Uterine leiomyoma with prominent lymphoid infiltrate

We present a case of a 35-year-old woman whose myomectomy specimen revealed a leiomyoma nodule diffusely infiltrated by lymphocytes which were shown to be clonal in nature. Lymphoid infiltration of leiomyomas is a rare occurrence, and this is the first case with molecular analysis.

Is visual loss due to giant cell arteritis reversible?

Giant cell arteritis (GCA) is a common systemic vasculitis with an unknown etiology. It mainly affects people older than 50 years of age and often presents with symptoms such as headache, jaw claudication, visual loss, polymyalgia rheumatica and increased erythrocyte sedimentation rate (ESR). Established blindness is irreversible if the steroid treatment is not administered within a few days. Here, we report a case of GCA in a patient with a normal ESR whose left eye perceived just light at the initiation of treatment. Immediately prior to the combined treatment with high dose oral steroids and cyclophosphamide, the ESR level had increased to 80 mm/h and the vision improved after the combined treatment four months later.

Prognostic value of CD44 variant 6 in laryngeal epidermoid carcinomas

BACKGROUND

CD44 variant exon 6 (v6) belongs to a family of transmembrane glycoproteins involved in cell adhesion.

OBJECTIVES

To determine the prognostic role of CD44v6 in laryngeal cancer and to examine its relation with other clinicopathologic prognostic factors.

DESIGN

A retrospective cohort study was designed with 93 laryngeal cancer cases. They were selected randomly from patients treated with laryngectomy between January 1, 1983, and December 31, 1993.

SETTING

Faculty of Medicine, Hacettepe University, Ankara, Turkey.

PATIENTS

The ages of the patients ranged from 31 to 73 years. Eighty-eight patients were men and 5 were women. Three had stage I, 33 had stage II, 27 had stage III, and 30 had stage IV disease at the time of surgery.

INTERVENTION

Histological sections of tumors and metastatic lymph nodes were reevaluated for several histopathological factors. Sections were stained using anti-CD44v6 monoclonal antibody by immunohistochemical methods.

RESULTS

CD44v6 expression was seen only in the lower one third of the normal squamous epithelium but in all layers of dysplasia and in situ carcinoma. Besides a general evaluation of tumor staining, immunostaining was evaluated separately for cell groups located in the center of neoplastic islands (nonbasal cells), at the periphery of the neoplastic islands (basal cells), and at the infiltration zones (marginal cells). Decreased disease-free survival was noted when there was extensive staining in the general evaluation and in cases with extensive staining in marginal and nonbasal cells (P =.03). Using Cox regression analysis, the greatest dimension of the largest metastatic lymph node and extensive expression of CD44v6 in nonbasal tumor cells were independent prognostic factors.

CONCLUSION

Our results suggest that CD44v6 expression is an important prognostic factor in laryngeal cancer.

A new flap model in rats: iliac osteomusculocutaneous flap

Although osteomusculocutaneous flaps are used frequently in clinical practice to repair defects involving soft tissue and bone, there are still many questions that remain to be answered regarding their basic physiology. To accomplish such basic science studies, simple and reliable animal osteomusculocutaneous flap models are needed. The purpose of this study was to describe a new flap model in rats--namely, the iliac osteomusculocutaneous flap. Thirty adult Wistar rats weighing 200 to 250 g were used in this experiment. In 15 rats, the vascular anatomy of the iliolumbar vessels and their relation with adjacent soft tissues and the iliac bone was determined by anatomic dissection. Based on this anatomic study, the iliac osteomusculocutaneous flap model was created in rats. The flap is comprised of a skin island (3 x 3 cm) in the flank region, a 1 x 1-cm segment of iliac bone, and an abdominal wall muscle cuff. In 10 rats, the flap was raised as an island flap based on its vascular pedicle of iliolumbar vessels, and was replaced in situ. In the remaining 5 rats, the flap was transferred to the groin region as a free flap. Direct observation on postoperative day 7 revealed that the skin island of all the flaps was completely viable. Bone scintigraphy performed on postoperative day 3 in free flaps demonstrated radionuclide uptake, indicating viability of the bony segment. The dye injection study revealed ink staining within blood vessels of the bone, confirming its viability. Microangiography of the flap demonstrated vascularity of each component of the flap by the iliolumbar vessels, including a distinct branch to the iliac bone. The authors conclude that the iliac osteomusculocutaneous flap of the rat is a simple and reliable flap model that offers the following advantages: (1) It is a true osteomusculocutaneous flap, (2) it can be used as a free flap without the need for an isogeneic rat, (3) the vascular pedicle is consistent, and (4) it is harvested from a small-animal species.

Fibroadenoma of the vulva

A well-circumscribed mass was excised from the vulva of a 37-year-old woman. Histological and immunohistochemical findings showed the characteristic features of fibroadenoma of breast. The concepts about the histogenesis of this lesion were discussed.

CD56+ lymphoma presenting as a testicular tumor

A case of an unusual lymphoma type, CD56 (+) T/NK lymphoma, presenting as a testicular tumor is described. A 35 year old man who presented with right testicular swelling, underwent right inguinal orchiectomy, with a presumptive diagnosis of abscess or malignancy. Histopathology showed a diffuse mixed large and small cell lymphoma with a focal angiocentric growth pattern. Immunohistochemically CD45RO and CD56 were found to be positive in the neoplastic cells. In situ hybridization assay for EBV showed the presence of EBV related small ribonucleic acid sequences (EBER) within the tumor cells. Despite systemic chemotherapy, the patient had an aggressive clinical course with two skin and left testicular recurrences in the first year of his disease.

Tumor metastasis to an oncocytoma

A case of squamous carcinoma of the lung metastatic to a renal oncocytoma is described. The terms "tumor-to-tumor metastasis" and "collision tumor" for describing the existence of two neoplasms in the same location are discussed.

Mohr syndrome in two sisters: prenatal diagnosis in a 22-week-old fetus with post-mortem findings in both

Oral-facial digital syndrome type II (OFP syndrome II; orofaciodigital syndrome II) is a rare autosomal recessive syndrome, first described by Mohr (1941). We present two sisters with Mohr syndrome from a consanguineous family. One is a three-day-old female patient, the other is 22-week-old fetus. Polydactyly with bifid thumbs in both hands, bilateral polysyndactyly of halluces, lateral polysyndactyly and bilateral pes equinovarus were demonstrated in the fetus sonographically. Corpus callosum agenesis, congenital heart disease, bilateral bifid thumbs and halluces and polydactyly were seen in both patients. In addition, post-mortem findings showed absence of olfactory nerve, single atrium. VSD, abnormal lung lobulation and natal teeth in the fetus. Absence of olfactory nerve and natal teeth have not been reported previously in Mohr syndrome.

Unilateral spinal anaesthesia with hyperbaric bupivacaine

BACKGROUND

The dosage of local anaesthetic and the time the patient must be kept in the lateral decubitus position for a unilateral spinal anaesthesia is not known. The aim of this study was to determine the ideal dosage of hyperbaric bupivacaine and the time required for the lateral decubitus position for a unilateral spinal block.

METHODS

Ninety patients who were scheduled to receive spinal block for surgery in the lower extremity were randomised into 9 groups (n = 10). The spinal block was performed through the L4-L5 intervertebral space with the patient in the lateral decubitus position. Patients in groups Ia, Ib, Ic; IIa, IIb, IIc; IIIa, IIIb, IIIc received 1.5 ml of 0.5%, 2 ml of 0.5%, and 2.5 ml of 0.5% hyperbaric bupivacaine solutions, respectively. The patients were turned to the supine position for 5 min after the injection in groups Ia, IIa, IIIa, 10 min after the injection in groups Ib, IIb, IIIb, and 15 min after the injection in groups Ic, IIc, IIIc. The onset and regression of sensory and motor block were checked and compared between the dependent and non-dependent sides in each group.

RESULTS

The rate of block progression of the non-dependent side was higher in the groups receiving 2.5 ml 0.5% hyperbaric bupivacaine solution than in the other groups; at the same time the level of block was higher and the duration of block was longer. The incidence of hypotension was 10-20% in these groups. In the 2 ml 0.5% hyperbaric bupivacaine solution groups, a satisfactory block level and duration of anaesthesia for surgery was obtained. The rate of block progression to non-dependent side in the groups receiving 1.5 ml of 0.5% hyperbaric bupivacaine solution was lower than the other groups, but the duration of block was shorter and the level of block was lower than the other groups.

CONCLUSION

For unilateral spinal anaesthesia in lower extremity operations, 2ml 0.5% hyperbaric bupivacaine solution for operations above the knee and 1.5 ml 0.5% hyperbaric bupivacaine solution for operations below the knee and keeping the patients for 10 min in the lateral decubitus position were found to be appropriate.

Changes in hydroxyproline levels in electric field tissue interaction

Guinea pigs when exposed to external electric field (1.9 kV/m) for 9 hrs/day for 3 days registered rise in the levels of hydroxyproline in liver, lung and kidney, suggesting increased synthesis of collagen.

Biochemical and structural approach to collagen synthesis under electric fields

The effects of electric fields of different intensities and directions on the collagen synthesis of guinea pigs was studied. The effects of vertical and horizontal electric fields of 1.9 kV/m and 0.9 kV/m, generated with voltages of 300 V and 150 V DC, respectively, on collagen synthesis, was evaluated by assessing the amount of hydroxyproline in the liver tissue, and by histological examination of tissue samples. The Stegemann-Stalder method was used to determine hydroxyproline content of the tissues. While the 0.9 kV/m vertical and horizontal electric fields substantially decreased the amount of hydroxyproline in the liver, the 1.9 kV/m electric fields in both directions increased the hydroxyproline content. The vertical electric field was more effective than the horizontal one both in the increases and the decreases. These findings were verified histologically.