The Effect of Body Mass Index on the Creation of an End-Colostomy in Rectal Cancer Patients

With the increasing prevalence of obesity, there has been a parallel increase in the incidence of rectal cancer. The association of body mass index (BMI) and end-colostomy creation versus primary anastomosis in patients undergoing proctectomy for rectal cancer has not been described. This is a retrospective study of patients with rectal cancer from 2012 to 2018 using data from the National Surgical Quality Improvement Project. 16,446 (92.1%) underwent primary anastomosis and 1,418 (7.9%) underwent creation of an end-colostomy. Patients with a BMI of 25-29.9 (overweight) comprised the most frequent group to have a proctectomy (reference group), but the least likely to have an end-colostomy. Patients with severe obesity (BMI 50+) had an adjusted odds ratio for end-colostomy of 2.7 (95% CI 1.5-4.7) compared to the reference group. Patients who have severe obesity should be counseled regarding the likelihood of an end-colostomy and may benefit from medical weight management or weight-loss surgery.

An analysis of sexual dimorphism in the tumor microenvironment of colorectal cancer

Women with colorectal cancer (CRC) have survival advantages over men, yet the underlying mechanisms are unclear. T cell infiltration within the CRC tumor microenvironment (TME) correlates strongly with survival. We hypothesized that women with CRC have increased T cell infiltration and differential gene expression in the TME compared to men. Tissue microarrays comprising primary tumor, tumor infiltrated lymph nodes, and uninvolved colon were created from CRC patients. Proportions of CD4 positive (CD4+) and CD8 positive (CD8+) T cells were identified using immunohistochemistry. TME immune- and cancer-related genetic expression from primary and metastatic CRC tumor were also evaluated via the NanoStringIO360 panel and The Cancer Genome Atlas Project database. CD4+ was higher in tumor samples from women compared to men (22.04% vs. 10.26%, p=0.002) and also in lymph node samples (39.54% vs. 8.56%, p=0.001). CD8+ was increased in uninvolved colon from women compared to men (59.40% vs. 43.61%, p=0.015), and in stage I/II tumors compared to III/IV in all patients (37.01% vs. 23.91%, p=0.009). Top CD8+ tertile patients survived longer compared to the bottom (43.9 months vs. 25.3 months, p=0.007). Differential gene expression was observed in pathways related to Treg function, T cell activity, and T cell exhaustion, amongst several others, in women compared to men. Thus, significant sexual dimorphism exists in the TME that could contribute to survival advantages observed in female patients with CRC.

Correlation of Supervised Independence and Performance with Procedure Difficulty amongst Surgical Residents Stratified by Post Graduate Year

PURPOSE

This study investigates the role of procedure difficulty on attending ratings of supervised levels of independence and procedural performance amongst general surgery residents, while accounting for case complexity.

METHODS

Attending ratings for residents were obtained from System for Improving and Measuring Procedural Learning (SIMPL) database. Current procedural terminology (CPT) codes were used to match procedures to a corresponding work relative value unit (wRVU) as a surrogate for procedure difficulty. Three categories of wRVU (<13.07, 13.07-22, >22) were identified using recursive partitioning. Procedures were also divided into 'Core' or 'Advanced' as defined by the American Board of Surgery Surgical Council on Resident Education (SCORE). Temporal advancement in resident skill was accounted for through academic quarterly analysis. A generalized estimating equations (GEE) approach was used to form separate multivariable logistic regression models for meaningful autonomy (MA) and satisfactory performance (SP) adjusted for potential clustering by program, subject, and rater. Models were further adjusted for core/advanced procedures, attending rated complexity, and academic quarter.

RESULTS

A total of 33,281 ratings were analyzed. Overall, 51.6% were rated as MA and 44.4% as SP. For core procedures, surgical residents rated as MA (53.5%) and SP (45.7%), which was twice as high as those for advance procedures (MA-29.2%, SP-29.0%). MA and SP both decreased with increasing wRVU (Figure 2 &3). Using a wRVU<13.07 as a reference, the adjusted odds ratios of MA and SP were significantly lower with increasing procedure difficulty, 0.44 for wRVU 13.07-22.0 and 0.24 for wRVU >22.00 (Table 3). Post graduate year (PGY) 5 residents in the final quarter of training obtain MA in 95.5% and SP 92.9% for core procedures with wRVU <13.07 (Table 4).

CONCLUSION

Increasing procedural difficulty is independently associated with decreases in meaningful autonomy and satisfactory performance. As residents approach graduation the level of meaningful autonomy and satisfactory performance both reach high levels for common core procedures but decrease as procedural difficulty increases.

Molecular Imaging of Inflammatory Disease

Inflammatory diseases include a wide variety of highly prevalent conditions with high mortality rates in severe cases ranging from cardiovascular disease, to rheumatoid arthritis, to chronic obstructive pulmonary disease, to graft vs. host disease, to a number of gastrointestinal disorders. Many diseases that are not considered inflammatory per se are associated with varying levels of inflammation. Imaging of the immune system and inflammatory response is of interest as it can give insight into disease progression and severity. Clinical imaging technologies such as computed tomography (CT) and magnetic resonance imaging (MRI) are traditionally limited to the visualization of anatomical information; then, the presence or absence of an inflammatory state must be inferred from the structural abnormalities. Improvement in available contrast agents has made it possible to obtain functional information as well as anatomical. In vivo imaging of inflammation ultimately facilitates an improved accuracy of diagnostics and monitoring of patients to allow for better patient care. Highly specific molecular imaging of inflammatory biomarkers allows for earlier diagnosis to prevent irreversible damage. Advancements in imaging instruments, targeted tracers, and contrast agents represent a rapidly growing area of preclinical research with the hopes of quick translation to the clinic.

Systemic infections mimicking thrombotic thrombocytopenic purpura

The absence of specific diagnostic criteria, the urgency to begin plasma exchange treatment, and the risk for complications from plasma exchange make the initial evaluation of patients with suspected thrombotic thrombocytopenic purpura (TTP) difficult. Systemic infections may mimic the presenting clinical features of TTP. In the Oklahoma TTP-HUS (hemolytic-uremic syndrome) Registry, 1989-2010, 415 consecutive patients have been clinically diagnosed with their first episode of TTP; in 31 (7%) the presenting clinical features were subsequently attributed to a systemic infection. All 31 patients had diagnostic criteria for TTP; 16 (52%) had the complete "pentad" of microangiopathic hemolytic anemia, thrombocytopenia, neurologic abnormalities, renal failure, and fever. Four (16%) of 25 patients who had ADAMTS13 measurements had <10% activity; three patients had a demonstrable ADAMTS13 inhibitor. Compared with 62 patients with severe ADAMTS13 deficiency (<10%) who had no recognized alternative disorders, patients with systemic infections had more frequent fever, coma, renal failure, and the complete "pentad" of clinical features. Seventeen different infectious etiologies were documented. A systematic literature review identified 67 additional patients with a diagnosis of TTP or HUS and also a systemic infection. Among all 98 patients, infections with 41 different bacteria, viruses, and fungi were documented, suggesting that many different systemic infections may mimic the presenting clinical features of TTP. Initial plasma exchange treatment is appropriate in critically ill patients with diagnostic features of TTP, even if a systemic infection is suspected. Continuing evaluation to document a systemic infection is essential to determine the appropriateness of continued plasma exchange.

Role of the vomeronasal organ in neonatal offspring recognition in sheep

Twenty-five pregnant Dorsett ewes were randomly divided into three groups to test if ewes use their vomeronasal organs for offspring recognition during nursing. One group of eight ewes (procaine) were made anosmic by irrigation of the nasal olfactory apparatus with a zinc sulphate procaine solution. The second group of nine ewes (cauterized) had their vomeronasal organs rendered nonfunctional by cauterization of the nasoincisive duct. The third group of eight ewes were the controls. Parturition was synchronized in all ewes with betamethasone on Day 145 of gestation. Maternal responsiveness was tested two separate times with 1- to 2-day-old alien lambs. Each alien lamb trial was conducted 24 h apart. Cauterized ewes allowed alien lambs to suckle and they were unable to distinguish alien lambs from their own lambs, whereas the ewes in both groups with functional vomeronasal organs (procaine and control) violently rejected any alien lamb's attempt to suckle. Thus, female sheep use their vomeronasal organs for neonatal offspring recognition.

The brachial plexus in the chacma baboon (Papio ursinus)

The brachial plexus in each of ten embalmed, mature chacma baboons was dissected to document the structure and branching pattern of this nerve plexus in this increasingly used research animal. In general, the brachial plexus in the chacma baboon was similar to the plexuses in the vervet and other Old World monkeys. However, several aspects were comparable to those observed in domestic animals. Thus the bipedal and quadrupedal abilities of the chacma baboon were reflected in the structure of its brachial plexus.

A comparative study of the thickness of the tunica muscularis in the forestomach and abomasum of grey, white and black Karakul lambs

Homozygous grey Karakul lambs are born with a lethal genetic factor responsible for death and weaning age. When put on a high roughage diet under field conditions they develop distended, thin-walled rumens and sand impacted abomasa. Homozygous white Karakul lambs have a similar factor but survive for a longer period. Black Karakul lambs are not affected. The present study was undertaken to compare by image analysis the thickness of the tunica muscularis of the forestomach and abomasum of 24-hour old grey, white and black Karakul lambs. One square centimetre samples were taken from equivalent areas in each case of the rumen, reticulum, omasum and abomasum of 38 embalmed Karakul lambs. Haematoxylin and eosin stained histological sections of each sample were studied with a Vids 2 Image Analyzer and the thickness of the circular and longitudinal muscle layers was measured. An analysis of variance indicated a significant difference between the groups in the thickness of the tunica muscularis of the rumen, reticulum and abomasum; the grey group displaying the thinnest and the black group the thickest. The omasa were not affected. The study indicates a reduction in thickness of the tunica muscularis of the homozygous grey and white lambs when compared to normal black lambs.

A comparative histological study of the number and size of the myenteric ganglia and neurones in the fore-stomach and abomasum of grey, white and black Karakul lambs

Homozygous grey Karakul lambs are born with a lethal genetic factor responsible for death at weaning age. When put on a high roughage diet under field conditions they develop distended, thin-walled rumens and sand impacted abomasa. Homozygous white Karakul lambs have a similar factor but survive for a longer period. Black Karakul lambs are not affected. The present study was undertaken to compare by image analysis the number and size of the myenteric ganglia, and the number of myenteric neurones in the walls of the fore-stomach and abomasum of 24-h-old grey, white and black Karakul lambs. One square centimetre samples were taken from analogous areas of the rumen, reticulum, omasum and abomasum of 38 embalmed Karakul lambs. Haematoxylin and eosin stained histological sections of each sample were studied with a Vids 2 Image Analyzer. One way analysis of variance indicated a significant difference between the groups regarding the number and size of the myenteric ganglia and in the number of myenteric neurones in the reticulum, rumen and abomasum. The number and size of the ganglia and the number of neurones was greatest in the black lambs and decreased progressively in the white and grey lambs. The omasum was not affected. It is suggested that the paucity of myenteric ganglia and neurones in the regions examined is instrumental in causing the lethal condition described above.

Atypical thyroid follicles arising from an ultimobranchial-like cyst in a postnatal canine thyroid gland

While investigating the intrinsic vasculature of the canine thyroid gland, atypical thyroid follicles were observed histologically, arising from a postnatal thyroid cyst of unknown origin, in stained sections of a male, 1-year-old, mesaticephalic dog. The animal was anesthetized, bled, killed by injection of Toxital directly into the heart, and perfused with 10% buffered neutral formalin solution. The thyroid tissue was fixed, embedded in paraffin, sectioned serially, and mounted on glass slides. Concordant with descriptions in the literature, this structure appeared to be a postnatal ultimobranchial-like cyst with direct connections to both ultimobranchial and mixed follicles. Seemingly, this observation has never been reported previously in the canine and would lend support to the hypothesis that ultimobranchial-like cysts may give rise to these atypical follicles. However, the authors are not totally convinced that all such thyroid cysts are solely ultimobranchial in orgin. A review of the literature supporting this contention is discussed.

Is there a caudal thyroid artery in the dog (Canis familiaris)?

Attempts have been made to establish extent of similarities as well as dissimilarities between the canine caudal thyroid and human inferior thyroid artery. On the basis of origin, course, relationship, branching pattern, major area of supply, level of anastomosis, occurrence, etc., it is proposed to rename the caudal thyroid of the dog as the tracheoesophageal artery.