Implant reconstruction after mastectomy-A review and summary of current literature.

INTRODUCTION: The landscape of breast reconstruction has changed significantly with a shift in focus to include the restoration of a patient's quality of life after cancer. Reconstructive options can be divided into alloplastic (implant based) and autologous (tissue based). This paper aims to provide a current educational summary regarding implant-based reconstruction after breast cancer surgery and review the current literature. METHOD: A review of the literature was conducted utilising standard PRISMA flowchart. Databases searched included Pubmed, EMBASE, and MEDLINE. RESULTS: Current practice is explored within the text, including types of implants, indications, and surgical approaches. Heterogenous cohorts, surgical technique variation, and selection bias can make comparison of the literature challenging. The major evidence reviews of implant-based reconstruction topics are discussed including, ADM use, radiotherapy, and complications. Despite the benefits of autologous reconstruction, implant-based techniques still represent a significant proportion of reconstructive breast procedures. However, implant-reconstruction is not without its risks and limitations and, with such variety in practice, there remains a lack of high-quality evidence guiding practice. Most importantly, patients need to be counselled about the pros and cons of each choice, particularly with the increasing utilisation of radiotherapy post-reconstruction. Ultimately, the patient and surgeon should reach a decision in full knowledge of the risks and potential outcomes. CONCLUSIONS: Further research is required into implant-based reconstructive therapy, which will allow a greater consensus for management and a pathway for both surgeons and patients.

ChatGPT versus human in generating medical graduate exam multiple choice questions-A multinational prospective study (Hong Kong S.A.R., Singapore, Ireland, and the United Kingdom).

INTRODUCTION: Large language models, in particular ChatGPT, have showcased remarkable language processing capabilities. Given the substantial workload of university medical staff, this study aims to assess the quality of multiple-choice questions (MCQs) produced by ChatGPT for use in graduate medical examinations, compared to questions written by university professoriate staffs based on standard medical textbooks. METHODS: 50 MCQs were generated by ChatGPT with reference to two standard undergraduate medical textbooks (Harrison's, and Bailey & Love's). Another 50 MCQs were drafted by two university professoriate staff using the same medical textbooks. All 100 MCQ were individually numbered, randomized and sent to five independent international assessors for MCQ quality assessment using a standardized assessment score on five assessment domains, namely, appropriateness of the question, clarity and specificity, relevance, discriminative power of alternatives, and suitability for medical graduate examination. RESULTS: The total time required for ChatGPT to create the 50 questions was 20 minutes 25 seconds, while it took two human examiners a total of 211 minutes 33 seconds to draft the 50 questions. When a comparison of the mean score was made between the questions constructed by A.I. with those drafted by humans, only in the relevance domain that the A.I. was inferior to humans (A.I.: 7.56 +/- 0.94 vs human: 7.88 +/- 0.52; p = 0.04). There was no significant difference in question quality between questions drafted by A.I. versus humans, in the total assessment score as well as in other domains. Questions generated by A.I. yielded a wider range of scores, while those created by humans were consistent and within a narrower range. CONCLUSION: ChatGPT has the potential to generate comparable-quality MCQs for medical graduate examinations within a significantly shorter time.

No evidence of benefit for laminar flow in theatre for sling-assisted, implant-based breast reconstruction.

INTRODUCTION: Recent years have seen a large increase in the proportion and number of sling-assisted, implant-based breast reconstructions. These are associated with significant rates of loss of the reconstruction. Various methods have been suggested to reduce this loss rate. One such method is the use of operating theatres with laminar flow. The majority of cases of sling-assisted, implant-based breast reconstruction in south-east Scotland are performed in two adjacent theatres, one with laminar flow and one without. This provided the opportunity to assess whether there was any difference in outcome potentially attributable to laminar flow. METHODS: Patients undergoing sling-assisted, implant-based breast reconstruction between August 2013 and December 2018 were studied with follow up for at least 6 months. RESULTS: 307 patients underwent a total of 470 procedures. 247 procedures were performed with laminar flow and 223 without. There was no difference in the indications for mastectomy, incision used or rates of smoking or radiotherapy between the two groups. Implant loss occurred in 15.8% of procedures with laminar flow and 14.3% of those without (p = 0.66). Wound problems occurred in 27.5% of procedures with laminar flow and 27.8% of those without (p = 0.97). There was no significant difference in loss rates between surgeons, mastectomy indication, sling materials or with chemotherapy use. Increased loss rates were observed in smokers, with radiotherapy, with incisions other than transverse, with larger breasts and with increasing patient weight. CONCLUSION: This study finds no evidence of benefit for laminar flow in theatre for sling-assisted, implant-based breast reconstruction.

Clinical Presentations of Breast Disorders in Pregnancy and Lactation.

The breast tissue undergoes significant physiological change during pregnancy and lactation. These changes can give rise to some unique disorders during pregnancy , puerperium and lactation or exaggerate pre-existing conditions. Clinical examination becomes less reliable due to textural change and density of breast tissue as a result of hormonal changes. The main symptoms during pregnancy and lactation are breast pain, mastitis, lactational abscess, breast lump, and blood- stained nipple discharge.Lactational mastitis/ abscess must be treated without delay. Open incision and drainage of lactational abscess is rarely required, any lactational abscess should be treated with appropriate antibiotics and ultrasound guided aspiration of the pus.Any breast lump during pregnancy and lactation should be investigated with triple assessment. Pregnancy associated breast cancer (PABC ) must be ruled out. The choice of investigations and treatment needs careful consideration. While ultrasound is the investigation of choice, mammography can be performed with abdominal shielding if malignancy is suspected. Core biopsy is necessary for evaluation of any breast pathology but it comes with risk of infection, bleeding, hematoma and even milk fistula.The treating clinical specialist must be aware of certain unusual unique clinical conditions in pregnancy and lactation including accessory axillary breast tissue, gigantomastia and Raynaud's phenomenon.

Biofilm Producing Multidrug Resistant Acinetobacter baumannii: An Emerging Challenge.

AIM: To study the quantitative method for biofilm formation and examine the correlation between biofilm formation and antibiotic resistance among the clinical isolates of Acinetobacter baumannii. MATERIALS AND METHODS: A total of 72 A. baumannii isolates from different clinical specimens were processed and confirmed by conventional microbiological methods. Antimicrobial susceptibility testing was performed by Kirby Bauer disc diffusion method using six antibiotics. Biofilm formation was studied by microtitre plate assay. RESULTS: Forty five (62.5%) of 72 isolates produced biofilm. Resistance to ampicillin-sulbactam was least. 36.1% isolates were resistant to imipenem, 66.6% to ceftazidime, 72.2% to ciprofloxacin, 80.5% to amikacin and 84.7% to piperacillin. Biofilm formers showed greater resistance to ampicillin- sulbactam, amikacin, ciprofloxacin and ceftazidime as compared to imipenem and piperacillin. In all 65 (90.3%) isolates showed multiple drug resistance. Correlation between multidrug resistance and biofilm formation was analysed statistically and p-value was found to be significant (p-value =0.0004; p-value < 0.05 is significant by Chi - Square Test). CONCLUSION: The study concludes that there a positive correlation between biofilm formation and multiple drug resistance in A. baumannii.

Breast reconstruction with the denervated latissimus dorsi musculocutaneous flap.

OBJECTIVE: To analyze clinical implications of the thoracodorsal nerve division in the latissimus dorsi musculocutaneous flap breast reconstruction. PATIENTS AND METHODS: Prospective cohort study was conducted on 29 patients. Breast reconstruction with latissimus dorsi musculocutaneous flap was performed unilaterally in 20 patients or bilaterally in 9 women (38 breasts). Thoracodorsal nerve was divided during reconstruction of 20 breasts (group 1) and was preserved for 18 breasts (group 2). Height, width, projection, area of the covering skin and volume of the reconstructed and healthy breasts were measured on the 3D images of the anterior chest wall, taken 6 weeks and 6 months postoperatively with the Di3D 3D camera. Data regarding tissue consistency, painfulness and animation of the reconstructed breast, symmetry of both breasts and overall satisfaction after the surgery were collected at 6 months. RESULTS: The reconstructed and healthy breasts decreased in volume in group 1 (-45.85 cm(3) ± 48.41 cm(3), p = 0.0004; -29.13 cm(3) ± 14.98 cm(3), p = 0.0009) and in group 2 (-31.5 cm(3) ± 25.35 cm(3), p = 0.0001; -15.4 cm(3) ± 21.96 cm(3), p = 0.0537). There were no differences in decrease in volume between groups 1 and 2 (p > 0.05). Respondents in group 1 in comparison to group 2 showed similar satisfaction of the tissue consistency of the reconstructed breast (p > 0.05) and the level of symmetry between both breasts (p > 0.05), gave lower scores for painfulness (p < 0.0001), animation (p < 0.0001) and higher scores for the overall satisfaction about the reconstructed breast (p = 0.0001). CONCLUSION: We suggest that division of the thoracodorsal nerve during latissimus dorsi musculocutaneous flap breast reconstruction is a useful undertaking to minimize unnatural animation of the reconstructed breast.

Congenital abnormalities of the breast.

Congenital abnormalities of the breast and chest wall are seen frequently in breast, pediatric and plastic surgery clinics. Management involves a multidisciplinary team approach. The treatment for many of these conditions includes surgical correction. If the child is still growing, treatment timing is crucial and many of the surgical corrective procedures require more than one operation over a number of years. Although these deformities have less impact on functional capacity, the psychological consequences can be serious in adolescent patients. They can experience embarrassment, social isolation and complexities during sexual development, and this results in problems with relationships. The aim of this article is to spread awareness among the medical community of this range of conditions, so appropriate referrals are made and their impact is reduced by timely appropriate surgical intervention if appropriate.

Evaluation of dose variation to normal and critical structures for lung hypofractionated stereotactic body radiation therapy.

PURPOSE: To quantify the dose received by normal and critical structures during lung stereotactic body radiation therapy (SBRT) when registered to tumor or bone. METHODS AND MATERIALS: Sixteen patients with lung cancer receiving a total dose of 50 Gy in 4fractions for lung SBRT were retrospectively studied. Cone-beam computed tomography (CT) was performed for all fractions, and the images obtained were registered with planning CT with respect tosoft tissue for target localization. Isocenter shifts were determined for each fraction from differences between the bony and tumor alignments; doses were then recalculated based on the new isocenters and summed over all 4 fractions to compare against the planned normal and critical tissue dose. The normal and critical structures evaluated were total and ipsilateral lung, spinal cord, and esophagus. The first data collected were isocenter coordinate shifts in all 3 Cartesian coordinates for both tumor andbony alignments. The second were the dose differences to the normal and critical structures fromthe planned and recalculated doses for alignment based on the tumor. RESULTS: The study showed that while the maximum isocenter coordinate shifts in any direction couldbe as much as 1.60 cm, the normal and critical structure dose variations between the original plans and the simulated plans showed almost no change. The mean volume of total lung that receivedat least 20Gy difference for total lung and ipsilateral lung were 0.01% and -0.04%, respectively. For the esophagus, spinal cord, and heart the maximum and mean dose differences were 0.25 Gy and -0.04 Gy, -0.08 Gy and -0.02 Gy, and 0.02 Gy and 0.05 Gy, respectively. CONCLUSIONS: Target localization using daily cone-beam CT with soft tissue registration was appropriate for minimizing the dose to the normal and critical structures without the need to re-plan due to the changes in the tumor position. For tumors located close to a critical structure, daily cone-beam CT is recommended to determine the appropriate isocenter shifts.

The C-terminal domain of the MutL homolog from Neisseria gonorrhoeae forms an inverted homodimer.

The mismatch repair (MMR) pathway serves to maintain the integrity of the genome by removing mispaired bases from the newly synthesized strand. In E. coli, MutS, MutL and MutH coordinate to discriminate the daughter strand through a mechanism involving lack of methylation on the new strand. This facilitates the creation of a nick by MutH in the daughter strand to initiate mismatch repair. Many bacteria and eukaryotes, including humans, do not possess a homolog of MutH. Although the exact strategy for strand discrimination in these organisms is yet to be ascertained, the required nicking endonuclease activity is resident in the C-terminal domain of MutL. This activity is dependent on the integrity of a conserved metal binding motif. Unlike their eukaryotic counterparts, MutL in bacteria like Neisseria exist in the form of a homodimer. Even though this homodimer would possess two active sites, it still acts a nicking endonuclease. Here, we present the crystal structure of the C-terminal domain (CTD) of the MutL homolog of Neisseria gonorrhoeae (NgoL) determined to a resolution of 2.4 Å. The structure shows that the metal binding motif exists in a helical configuration and that four of the six conserved motifs in the MutL family, including the metal binding site, localize together to form a composite active site. NgoL-CTD exists in the form of an elongated inverted homodimer stabilized by a hydrophobic interface rich in leucines. The inverted arrangement places the two composite active sites in each subunit on opposite lateral sides of the homodimer. Such an arrangement raises the possibility that one of the active sites is occluded due to interaction of NgoL with other protein factors involved in MMR. The presentation of only one active site to substrate DNA will ensure that nicking of only one strand occurs to prevent inadvertent and deleterious double stranded cleavage.

A rare case of a mid sigmoid tumour presenting as an intussuscepting low rectal tumour causing clinical dilemma in a 22-year-old: a case report.

A 22-year-old man presented to clinic with a 1 year history of bloody diarrhoea and weight loss. Flexible sigmoidoscopy showed the presence of a low polypoidal rectal carcinoma. Whilst awaiting neoadjuvant chemo-radiotherapy, the patient presented to accident and emergency with an anal protrusion of the tumour. An emergency laparotomy unexpectedly revealed a mid sigmoid tumour which had intussuscepted through the anus and therefore required an anterior resection as opposed to an abdomino-perineal resection. Colorectal carcinoma presents in a specifically unique pattern in patients less than 30 years. We present this rare case with a brief review of the literature.

A case-control study identifying chromosomal polymorphic variations as forms of epigenetic alterations associated with the infertility phenotype.

OBJECTIVE: To study the association of chromosomal polymorphic variations with infertility and subfertility. DESIGN: A comparative case-controlled association study using cytogenetic techniques to compare the frequency of chromosomal variations in infertile individuals versus fertile controls. SETTING: Department of Infertility Management and Assisted Reproduction, Jaslok Hospital and Research Centre, Mumbai, India. PATIENT(S): 760 infertile individuals and 555 fertile controls. INTERVENTION(S): ICSI, IUI, karyotyping, inverted 4',6-diamidino-2-phenylindole (DAPI), CBG banding. MAIN OUTCOME MEASURE(S): Frequency of chromosomal polymorphic variations in infertile individuals undergoing infertility treatment versus fertile individuals. RESULT(S): A highly statistically significant increase in the frequency of total chromosomal variants in infertile women (28.31% vs. 15.16%) and infertile men (58.68% vs. 32.55%) was observed. The frequency of 9qh+ was statistically significantly increased in women with primary infertility (16.22% vs. 6.41%) and in men with severe male factor infertility (14.69% vs. 4.25%). A highly statistically significant increase in the frequency of Yqh+ was observed in men whose wives had a bad obstetric history (30.20% vs. 12.74%). CONCLUSION(S): The statistically significantly higher incidence of heterochromatic variations found in infertile individuals stresses on the need to evaluate their role in infertility and subfertility. Potential epigenetic, genetic, and chromosomal modifications could be associated with certain complex disorders such as infertility and bad obstetric history.

Male breast cancer: is the scenario changing.

BACKGROUND: The overall incidence of male breast cancer is around 1% of all breast cancers and is on the rise. In this review we aim to present various aspects of male breast cancer with particular emphasis on incidence, risk factors, patho-physiology, treatment, prognostic factors, and outcome. METHODS: Information on all aspects of male breast cancer was gathered from available relevant literature on male breast cancer from the MEDLINE database over the past 32 years from 1975 to 2007. Various reported studies were scrutinized for emerging evidence. Incidence data were also obtained from the IARC, Cancer Mondial database. CONCLUSION: There is a scenario of rising incidence, particularly in urban US, Canada and UK. Even though more data on risk factors is emerging about this disease, more multi-institutional efforts to pool data with large randomized trials to show treatment and survival benefits are needed to support the existing vast emerging knowledge about the disease.

Degradation of raffinose oligosaccharides in soymilk by immobilized alpha-galactosidase of Aspergillus oryzae.

Alpha-galactosidase was immobilized in a mixture of k-carrageenan and locust bean gum. The properties of the free and immobilized enzyme were then determined. The optimum pH for both the soluble and immobilized enzyme was 4.8. The optimum temperature for the soluble enzymes was 50 degrees C, whereas that for the immobilized enzyme was 55 degrees C. The immobilized enzyme was used in batch, repeated batch, and continuous modes to degrade the raffinose-family sugars present in soymilk. Two hours of incubation with the free and immobilized alpha-galactosidases resulted in an 80% and 68% reduction in the raffinose oligosaccharides in the soymilk, respectively. In the repeated batch, a 73% reduction was obtained in the fourth cycle. A fluidized bed reactor was also designed to treat soymilk continuously and the performance of the immobilized alpha-galactosidase tested at different flow rates, resulting in a 90% reduction of raffinose-family oligosaccharides in the soymilk at a flow rate 40 ml/h. Therefore, the present study demonstrated that immobilized alpha-galactosidase in a continuous mode is efficient for reducing the oligosaccharides present in soymilk, which may be of considerable interest for industrial application.

Reduction of flatus-inducing factors in soymilk by immobilized alpha-galactosidase.

Alpha-galactosidase from Aspergillus oryzae was immobilized on chitosan beads using glutaraldehyde as a cross-linking agent. The general properties of free and immobilized enzymes were determined. The optimum pH for the free and immobilized enzymes was 4.8 and 4.6 respectively. The optimum temperature for the free enzyme was 50 degrees C, whereas that of immobilized enzyme was increased to 56 degrees C. Kinetic parameters were determined with synthetic substrate (p-nitrophenyl alpha-D-galactopyranoside) and raffinose. Immobilized enzyme showed a higher Km and a lower Vmax than the free enzyme. The immobilized enzymes were used in batch, repeated and continuous mode. A level of 92% hydrolysis was observed at a flow rate of 60 ml/h. The immobilized enzyme was used repeatedly ten times without any change in the performance of the immobilized enzyme in fluidized-bed reactor. The results obtained are of considerable interest for industrial purposes.

Gigantomastia: A problem of local recurrence.

Gigantomastia by definition means bilateral benign progressive breast enlargement to a degree that requires breast reduction surgery to remove more than 1800 g of tissue on each side. It is seen at puberty or during pregnancy. The etiology for this condition is still not clear, but surgery remains the mainstay of treatment. We present a unique case of Gigantomastia, which was neither related to puberty nor pregnancy and has undergone three operations so far for recurrence.

Breast duct micro-endoscopy: a study of technique and a morphological classification of endo-luminal lesions.

Endoscopic visualisation of the human mammary ductal system has been sporadically reported over the last decade. Recent rapid and groundbreaking developments in the field of optics have made the previously unseen labyrinth of mammary ducts more easily accessible to direct visualisation and examination. The emphasis so far has been on visualisation of ectatic ducts with pathological nipple discharge. The purpose of this study was to assess the feasibility of mammary duct epithelium in patients with a range of other pathologies. Based on our findings we have developed a morphological classification of endo-luminal lesions seen on endoscopy. We successfully conducted ex vivo mammary duct micro-endoscopy on 115 ducts in 35 mastectomy specimens. Visualisation of mammary duct epithelium was achieved using a solid rod depth of field imaging micro-minimally invasive (DOFI MMI, Acueity Inc., USA) and more recently the LaDuScope (PolyDiagnost GmbH, Germany) system. Both these systems consist of 0.9 mm maximum outer diameter micro-endoscope, with working channels 0.35 and 0.45 mm, respectively. Saline or air insufflation was used to keep the mammary ducts from collapsing. An average of 3.3 (median 3) mammary ducts could be identified and cannulated in all 35 mastectomy specimens (total of 115 ducts). Visualisation beyond 2 cm of the ductal system was possible in 23/35 (66%) of specimens. Abnormalities were visualised in 40% of the ducts. The maximum depth we could negotiate to was 8.9 cm and in doing so manoeuvred past eight duct divisions. In 34% of ducts cannulated, we were able to navigate the scope beyond at least one bifurcation of the principal duct and in 16% of cases extensive intra-ductal navigation was possible. Peripheral ducts were visualised in 16% of cases. False passages were created in 16% of cases. Previous history of smoking, parity, breastfeeding and radiotherapy offered neither significant advantages nor disadvantages for the technique nor did they increase or decrease the number of normal ducts visualised per specimen. This study showed that mammary duct micro-endoscopy is a practical and technically feasible procedure even in the absence of nipple discharge, in normal non-ectatic milk ducts. A simple morphological classification of endoscopically visualised intra-ductal abnormalities is suggested.