A comparison of double single suture-button fixation,suture-button fixation,and screw fixation for ankle syndesmosis injury: A retrospective cohort study

Different methods have been used throughout the years for syndesmotic injury but there is no consensus on the ideal treatment. Some methods are expensive and some have more complications. The aim of this study is to compare single suture endobutton with double suture endobutton and screw fixation for syndesmotic injury.Sixty nine patients with syndesmotic injury with fibular fractures whom were treated with a single interosseous suture endobutton system (ZipTight^TM, Zimmer Biomet), a double interosseous suture endobutton system (ZipTight^TM, Zimmer Biomet) and 1 syndesmotic screw (TST, Istanbul, Turkey) were included in this study. Functional and radiological results from patient records between 2015 and 2018 were retrospectively evaluated.Twenty patients were treated with the double interosseous suture endobutton, 23 were treated with the single interosseous suture endobutton, and 26 were treated with traditional AO screw fixation. Three patients from the screw fixation group (11.5%) required revision surgery (P < .05). All the radiologic and clinical outcomes were statistical similar in all 3 groups.Our findings showed that the interosseous suture endobutton system is at least as safe as the screw fixation technique for treatment of syndesmosis joint injuries and can be used as an alternative to the screw method. The interosseous suture endobutton system eliminates the need for a second surgery to remove the hardware, which minimizes the probability of re-diastasis. Since our results showed no statistical difference between single and double interosseous suture endobutton systems, the less costly single endobutton system may be the better alternative.     

Maternal mortality in rural Bangladesh: the Tangail District

A study was conducted from September 1982 to August 1983 in the Tangail district of Bangladesh to estimate the maternal mortality level there and identify its causes and correlates. A rate of 56.6 per 10,000 live births was found, with abortion-related deaths contributing nearly 10 deaths per 10,000 live births. The major causes of maternal mortality were found to be obstructed labor and sepsis caused by improperly performed abortion. Those at high risk were mothers below age 20 and above age 30 and those above parity four. No inverse relationship was found between maternal mortality and socioeconomic status, as might be expected. Community-level pregnancy monitoring programs, increased attention on the part of family planning workers toward teenaged, older, and high parity mothers, and nutrition supplement programs for anemic mothers are recommended.     

α-Alkylation of amino acid derivatives: Synthesis and chiral resolution of [C]β-aminoisobutyric acid

A synthesis of ¹¹C-labeled β-aminoisobutyric acid ([¹¹C]β-AIB) and its enantiomeric resolution by high performance liquid chromatography (HPLC) are reported. β-Alanine ethyl ester 2 was converted to benzaldimine-β-alanine ethyl ester 3 in 87% yield. Treatment of the imine derivative 3 with lithium diisopropylamide (1.1 eq) in tetrahydrofuran at −78 °C, followed by addition of cold iodomethane (1.1 eq) produced the α-methylated benzaldimine-β-alanine ethyl ester 4 in 73% chemical yield. Deprotection of the amino group by acidic hydrolysis followed by basic hydrolysis of the ester group produced the desired product 1 in 37% chemical yield. Labeling was accomplished using [¹¹C]methyl iodide. The radiola-beled product was purified by HPLC using a semipreparative reversed-phase C-18 column and 2 mM phosphate buffer (pH 5.9) as the mobile phase. The synthesis time was 35–40 min including HPLC purification, with 20–60% radiochemical yield (decay corrected). Radiochemical purity was >99%, with average specific activity being 450 mCi/μmol. Enantiomers of β-AIB were well separated by analytical HPLC using a chiral column and aqueous perchloric acid as the mobile phase. (S)-β-AIB was eluted at 17.4 min and the (R)-enantiomer was eluted at 20.0 min when the jacketed column was maintained at low temperature by circulation of ice-cold water, and the pH of the mobile phase was 1.05.     

Radiosynthesis of 2'-deoxy-2'-[18F]-fluoro-5-methyl-1-beta-L-arabinofuranosyluracil ([18F]-L-FMAU) for PET.

Radiosynthesis of 2'-deoxy-2'-[(18)F]-fluoro-5-methyl-1-beta-L-arabinofuranosyluracil ([(18)F]-L-FMAU) is reported. Compound 1 was synthesized and converted to 2-triflate 2. Compound 3 was prepared from 2 using tetrabutylammonium[(18)F]fluoride, converted to 4, and then coupled with 5. The crude product was hydrolyzed, and purified by HPLC to obtain 7a. The radiochemical yield of [(18)F]-L-FMAU was 26% decay corrected (d.c.) in four runs with radiochemical purity >99% and specific activity 2200 mCi/micromol. The synthesis time was 3.3-3.5h from the end of bombardment (EOB).     

Determinants of Hepatitis B Virus (HBV) Infection Among University Students in Central Bangladesh

This study aimed to determine the seroprevalence and determinants of hepatitis B virus (HBV) infection among university students in Bangladesh. This cross-sectional study was conducted among 614 students from five universities in central Bangladesh. Data were collected on demographic information, immunization history, medical and blood transfusion history through the face-to-face interview. Blood samples were collected and screened for anti-HBsAg using ELISA, HBsAg Rapid Test-cassette, and immune chromatographic test. The overall seroprevalence of HBV infection was 5.0%, and vaccination coverage was 19.2% among the participants. Students having a history of surgery (OR 11.004, 95% CI 3.211–37.707), blood transfusion (OR 5.651, 95% CI 0.965–33.068), being married (OR 4.776, 95% CI 1.508–15.127), and not being vaccinated (OR 9.825, 95% CI 1.130–85.367) were at higher risk of being infected by HBV. This study showed the endemicity of HBV infection among the Bangladeshi population. Marriage, surgical or blood transfusion history, not being vaccinated were the determinants of HBV infection within the study population. Public health initiatives for preventing HBV infection at the university levels should be envisaged.

     

Management of thyroid carcinoma-an experience in Bangladesh

All patients (n=154) of thyroid malignancy admitted in the Otoluryngology Department of Bangabandhu Sheikh Mujib Medical University (former IPGMR) between 1986 and 2000 were retrospectively analyzed to find out the extent and result of surgery used for thyroid carcinoma. The other objectives were to find out the incidence of differentiated thyroid carcinoma among the thyroid malignancy and also to find out the age, sex and clinical presentation of papillary and follicular carcinoma. Among all the thyroid malignancy (n-154), Differentiated Thyroid Carcinoma (DTC) was seen in 130 (84.41%) cases, where as papillary carcinoma occurred in 98(63.64%), and follicular carcinoma in 32(20.77%)cases. On the basis of risk factors, the DTC were designated as low and high risk. The year-wise incidence of DTC revealed increasing trend from 1986 (3 cases) to 2000 (23 cases). Among the 98 papillary thyroid carcinoma highest number of cases (35.71%) were seen in 31-40 year age group. The male to female ratio was 1: 1.64. In follicular carcinoma, highest number (35.25%) of cases were also seen in 31-40 year age group. The male to female ratio was 1:1.66. The commonest presentation in papillary carcinoma was thyroid swelling (96.93%). The other presentations were occult thyroid (3.06%), Cervical lymph node metastasis (38.77%) and distant metastasis (2.04%). In Follicular carcinoma, the presentations were thyroid swelling (100%), Cervical lymph node metastasis (6.25%) and Distant metastasis (21.87%). In this series, low risk DTC were treated by Lobectomy & Isthmusectomy plus Thyroxin. In low risk group the rate of recurrence was 6.89% and the mortality was nil in five years follow-up. Except two inoperable cases, all high risk patients were managed by Total thyroidectomy (with or without neck dissection, plus removal of metastatic lesion when required) with Radioiodine ablation plus Thyroxin. . The rate of recurrence was 7.81% and mortality was 1.56% in high risk group in similar period of time. Vocal cord palsy were noted in 5 (3.84%) unilateral, and inane (0.76%) bilateral cases. Hypoparathyroidism was found in 4.61%.     

Early detection of chemoradioresponse in esophageal carcinoma by 3'-deoxy-3'-3H-fluorothymidine using preclinical tumor models.

PURPOSE: Early identification of esophageal cancer patients who are responding or resistant to combined chemoradiotherapy may lead to individualized therapeutic approaches and improved clinical outcomes. We assessed the ability of 3'-deoxy-3'-(18)F-fluorothymidine positron emission tomography (FLT-PET) to detect early changes in tumor proliferation after chemoradiotherapy in experimental models of esophageal carcinoma. EXPERIMENTAL DESIGN: The in vitro and ex vivo tumor uptake of [(3)H]FLT in SEG-1 human esophageal adenocarcinoma cells were studied at various early time points after docetaxel plus irradiation and validated with conventional assessments of cellular proliferation [thymidine (Thd) and Ki-67] and [(18)F]FLT micro-PET imaging. Imaging-histologic correlation was determined by comparing spatial Ki-67 and [(18)F]FLT distribution in autoradiographs. Comparison with fluorodeoxyglucose (FDG) was done in all experiments. RESULTS: In vitro [(3)H]FLT and [(3)H]Thd uptake rapidly decreased in SEG-1 cells 24 hours after docetaxel with a maximal reduction of over 5-fold (P = 0.005). The [(3)H]FLT tumor-to-muscle uptake ratio in xenografts declined by 75% compared with baseline (P < 0.005) by 2 days after chemoradiotherapy, despite the lack of change in tumor size. In contrast, the decline of [(3)H]FDG uptake was gradual and less pronounced. Tumor uptake of [(3)H]FLT was more closely correlated with Ki-67 expression (r = 0.89, P < 0.001) than was [(3)H]FDG (r = 0.39, P = 0.08). Micro-PET images depicted similar trends in reduction of [(18)F]FLT and [(18)F]FDG tumor uptake. Autoradiographs displayed spatial correlations between [(18)F]FLT uptake and histologic Ki-67 distribution in preliminary studies. CONCLUSIONS: FLT-PET is suitable and more specific than FDG-PET for depicting early reductions in tumor proliferation that precede tumor size changes after chemoradiotherapy.     

Comparison of radiolabeled nucleoside probes (FIAU, FHBG, and FHPG) for PET imaging of HSV1-tk gene expression.

The efficacy of 3 radiolabeled probes of current interest for imaging herpes simplex virus type 1 thymidine kinase (HSV1-tk) expression in vivo with PET, including (124)I- or (131)I-labeled 2'-fluoro-2'-deoxy-1-beta-D-arabinofuranosyl-5-iodouracil (FIAU), (18)F-labeled 9-[4-fluoro-3-(hydroxymethyl)butyl]guanine (FHBG), and (18)F-labeled 9-[3-fluoro-1-hydroxy-2-propoxymethyl]guanine (FHPG), was compared. METHODS: Two established rat glioma cell lines, stably transduced RG2TK+ and wild-type RG2, were used for paired comparisons of probe accumulation in vitro and for paired comparisons of subcutaneous xenografts produced from these cell lines in athymic rnu/rnu rats. RESULTS: The in vitro paired probe uptake (0-3 h) comparisons in RG2TK+ cells showed that FIAU accumulation was 15-fold greater than that of FHBG and 41-fold greater than that of FHPG. The net accumulation rate values (+/-SD) calculated for RG2TK+ cells were 0.317 +/- 0.066, 0.022 +/- 0.001, and 0.0077 +/- 0.0003 mL/min/g cells for FIAU, FHBG, and FHPG, respectively. These results and similar uptake studies in RG2 wild-type cells suggest a possible cell membrane transport limitation for FHBG and FHPG. The paired 2-h in vivo uptake studies produced similar differences in RG2TK+ xenografts for FIAU and FHBG (1.22 +/- 0.21 vs. 0.074 +/- 0.49 %dose/g) and for FIAU and FHPG (1.27 +/- 0.14 vs. 0.023 +/- 0.008 %dose/g). These differences were clearly visible on the images. FIAU accumulation at 24 h was 1.53 +/- 0.40 %dose/g. Plasma clearance was FHBG > FHPG > FIAU. The FIAU images showed significant stomach and some intestinal background radioactivities, whereas hepatobiliary and intestinal background activities were very high for the guanosine analogs (FHBG > FHPG). Dynamic imaging showed early ( approximately 10 min) selective localization of FIAU in RG2TK+ xenografts, whereas FHBG and FHPG are being cleared from the HSV1-tk transduced and wild-type xenografts over the initial 2-h imaging period. CONCLUSION: The in vitro and in vivo results (including the PET images) show that FIAU is a substantially more efficient probe than FHBG or FHPG for imaging HSV1-tk expression, with greater sensitivity and contrast as well as lower levels of abdominal background radioactivity at 2 and 24 h.     

Single amino acid substitution in the Fc region of chimeric TNT-3 antibody accelerates clearance and improves immunoscintigraphy of solid tumors.

Recent studies in antibody catabolism have identified residues at the CH2-CH3 interface of the IgG heavy chain critical for serum persistence of immunoglobulins. Amino acid substitutions in the Fc region of murine IgG1 were shown to drastically accelerate antibody clearance in mice. Our laboratory has previously described a human-mouse chimeric TNT-3 (chTNT-3) monoclonal antibody directed against a universal nuclear antigen that has potential for the radioimmunotherapy of many solid tumors. In the current study, we engineered a chTNT-3 mutant containing a single amino acid substitution, to determine whether a more rapid clearance profile would make the antibody suitable for diagnostic imaging. METHODS: A single amino acid substitution in the CH2 domain of the human gamma1 constant region was made by polymerase chain reaction mutagenesis. High-level expression was achieved using the Glutamine Synthetase Gene Amplification System, and the chTNT-3 mutant was purified by protein A affinity and ion-exchange chromatography. A radioimmunoassay was performed to examine antigen binding, and in vivo studies were undertaken to evaluate clearance and tumor targeting in human tumor xenograft models. RESULTS: The chTNT-3 mutant retained the high affinity of chTNT-3, with a binding constant of 1.5 x 10(-9) mol/L. The mutant was eliminated rapidly from BALB/c mice, with a beta-phase half-life of 33.8 h, compared to 134.2 h for chTNT-3. Moreover, biodistribution studies in human colon tumor-bearing nude mice reflected this accelerated clearance. Tumor levels of the mutant were, respectively, 65%, 39%, and 36% of the tumor levels achieved with the parental chTNT-3 6, 12, and 24 h postinjection. The rapid clearance of the chTNT-3 mutant from the blood resulted in higher tumor-to-normal organ ratios for many normal tissues. Imaging of tumor-bearing mice with 99mTc-labeled chTNT-3 mutant demonstrated early visualization of tumors in 3 different solid tumor xenograft models. CONCLUSION: The accelerated clearance produced by a single amino acid substitution in the Fc region of chTNT-3 leads to improved imaging in tumor-bearing mice. These studies suggest that a rapidly clearing antibody generated by this approach may be useful for the immunoscintigraphy of human tumors.