Orbital controls on eastern African hydroclimate in the Pleistocene.

Understanding eastern African paleoclimate is critical for contextualizing early human evolution, adaptation, and dispersal, yet Pleistocene climate of this region and its governing mechanisms remain poorly understood due to the lack of long, orbitally-resolved, terrestrial paleoclimate records. Here we present leaf wax hydrogen isotope records of rainfall from paleolake sediment cores from key time windows that resolve long-term trends, variations, and high-latitude effects on tropical African precipitation. Eastern African rainfall was dominantly controlled by variations in low-latitude summer insolation during most of the early and middle Pleistocene, with little evidence that glacial-interglacial cycles impacted rainfall until the late Pleistocene. We observe the influence of high-latitude-driven climate processes emerging from the last interglacial (Marine Isotope Stage 5) to the present, an interval when glacial-interglacial cycles were strong and insolation forcing was weak. Our results demonstrate a variable response of eastern African rainfall to low-latitude insolation forcing and high-latitude-driven climate change, likely related to the relative strengths of these forcings through time and a threshold in monsoon sensitivity. We observe little difference in mean rainfall between the early, middle, and late Pleistocene, which suggests that orbitally-driven climate variations likely played a more significant role than gradual change in the relationship between early humans and their environment.

Design and Delivery of the Clinical Integrative Puzzle as a Collaborative Learning Tool.

Well-designed collaborative learning tools can provide an opportunity for engaging student experiences that foster deep learning and act as a scaffold for enculturation to the profession through refinement of professional collaborative skills. The clinical integrative puzzle is a paper-and-pencil or computer-based teaching and learning activity that combines disciplinary knowledge with clinical reasoning and problem solving. Effective design and implementation of clinical integrative puzzles requires a multidisciplinary approach to design, a positive classroom climate, and a set of illness scripts (e.g., clinical cases or scenarios) that are similar yet have key differentiating features that provide students with the opportunity to exercise clinical reasoning skills. The tool allows students to co-construct knowledge and develop professional competencies and allows instructors to assess and respond to student learning in a safe and supportive environment, even with large student numbers. The tool can also be used in a summative fashion. This article provides a brief review of the use of this instructional tool and offers tips for design and implementation.

Medical management of esophageal perforation secondary to esophageal foreign bodies in 5 dogs.

OBJECTIVE: To describe 5 cases of conservative management of substantial esophageal perforation in dogs. SERIES SUMMARY: Five dogs presented with an esophageal foreign body (EFB) and resultant esophageal perforation. Clinical signs at presentation included tachycardia, tachypnea, and increased respiratory effort. Thoracic radiography was performed in all cases, and in each case, pleural and mediastinal effusion was present, suggesting esophageal perforation prior to endoscope-guided removal. A full thickness esophageal defect was visualized after foreign body removal in 4/5 cases. Treatment included IV crystalloid fluid therapy, IV antimicrobials, analgesia, and proton pump inhibitors in all cases. Two dogs had a percutaneous endoscopically placed gastrostomy feeding tube placed and 1 dog received prednisolone sodium succinate IV because of marked pharyngeal inflammation. Complications after EFB removal included pneumothorax (n = 2) and pneumomediastinum (n = 4). Four of the 5 dogs survived to discharge and did not have complications 2-4 weeks following discharge. One dog was euthanized as result of aspiration pneumonia following EFB removal. NEW OR UNIQUE INFORMATION PROVIDED: Traditionally, surgical management of esophageal perforations has been recommended. This can be a costly and invasive procedure and requires a high degree of surgical skill. In this report, conservative management of substantial esophageal perforation in 5 dogs is described; medical management may be a viable treatment option in dogs with perforation of the esophagus due to EFB.

Acute and chronic effects of sprint interval exercise on postprandial lipemia in women at-risk for the metabolic syndrome.

Individuals diagnosed with the metabolic syndrome (MetS) exhibit elevated postprandial lipemia (PPL). The aims of this investigation were to determine 1) if an acute bout of sprint interval training (SIT) attenuates PPL; and 2) if the attenuation of PPL following 6 wk of SIT is magnified compared with a single session of SIT prior to training in women at-risk for MetS (n = 45; 30-65 yr). Women were randomized to SIT (n = 22) or a nonexercise control (n = 23; CON) for 6 wk. Postprandial responses to a high-fat meal challenge (HFMC) were assessed in the CON group before (B-HFMC) and after (Post-HFMC) without prior exercise and in the SIT group at baseline (B-HFMC) without prior exercise, after an acute bout of SIT (four 30-s all-out sprints with 4-min recovery) prior to (Pre-HFMC), and after the 6-wk intervention (Post-HFMC). Responses to the HFMC were assessed by collecting venous blood samples in the fasted state and at 0, 30, 60, 120, and 180 min postprandial. Compared with baseline, an acute bout of SIT before (Pre-HFMC) and after the 6-wk intervention (Post-HFMC) significantly attenuated fasted TG (P < 0.05; 16.6% and 12.3%, respectively) and postprandial area under the curve (13.1% and 9.7%, respectively; tAUC) TG responses. There was no difference in fasted or tAUC TG responses between Pre-HFMC and Post-HFMC. SIT is an effective mode of exercise to reduce fasted and postprandial TG concentrations in women at-risk for MetS. Six weeks of SIT does not magnify the attenuation of PPL in response to a single session of SIT.

Foramen of Winslow hernia: a minimally invasive approach.

Hernias through the foramen of Winslow comprise 8 % of all internal hernias and the majority contain incarcerated bowel. Clinical signs are often non-specific and delay in diagnosis associated with a mortality rate that approaches 50 %. Management is urgent surgical reduction with bowel decompression and resection of devitalized bowel. A foramen of Winslow hernia (FWH) has traditionally been managed via an exploratory laparotomy incision and the vast majority of cases describe an open approach. We describe a minimally invasive approach to the management of an incarcerated FWH requiring decompression and bowel resection.

Magnetic lower esophageal sphincter augmentation device removal.

Implantation of a magnetic lower esophageal sphincter augmentation device is now an alternative to fundoplication in the surgical management of gastroesophageal reflux disease (GERD). Although successful management of GERD has been reported following placement of the device, there are instances when device removal is needed. The details of the technique for laparoscopic magnetic lower esophageal sphincter device removal are presented to assist surgeons should device removal become necessary.

Analysis of perioperative factors and cost comparison of single-incision and traditional multi-incision laparoscopic cholecystectomy.

BACKGROUND: Recent technological advances in single-incision platforms have allowed many general surgeons to add single-incision laparoscopic cholecystectomy (SILC) to their armamentarium. However, adopting new surgical technologies comes at a cost to the patient and the surgeon. This study compared retrospective case-matched SILC and traditional multi-incision laparoscopic cholecystectomy (MILC) to evaluate the effects of SILC on perioperative outcomes and patient cost. METHODS: The study compared 50 patients who underwent SILC with a case-matched population of individuals who underwent traditional MILC. The SILC technique was performed using one of three commercially available single-incision platforms currently used for single-incision laparoscopic surgery (SILS) cholecystectomies. All the SILS platforms were placed in a 2-cm supraumbilical incision. All statistical analyses were performed using Microsoft Excel 2008 for Macintosh, with statistical significance determined by a p value of 0.05 or less. RESULTS: The average operative time was 42 min for the SILC group and 45 min for the MILC group. The difference was not statistically significant. Similarly, the average estimated blood loss was 14 ml for the SILC group and 11 ml for the MILC group. Again, the difference was not statistically significant. Moreover, the body mass index (BMI) did not differ statistically between the SILC group (28.4 kg/m(2)) and the MILC group (32.2 kg/m(2)). The average patient cost was $18,447 for SILC and $17,701 for MILC, yielding a cost difference of $746. This difference was not statistically significant. CONCLUSIONS: At the authors' institution, SILS cholecystectomy was performed with blood loss, operating room time, and cost equal to that for MILC. Further research is necessary to assess the economic feasibility of SILC and the trade-off of cost with the improved cosmesis, decreased pain, greater patient satisfaction, reduced postoperative analgesic requirement, and faster return to work to determine the overall value and superiority of SILC compared with MILC.

Laparoscopic ventral hernia repair: does primary repair in addition to placement of mesh decrease recurrence?

BACKGROUND: The advent of laparoscopic ventral hernia repair (LVHR) not only reduced the morbidity associated with open repair but also led to a decrease in the hernia recurrence rate. However, the rate continues to remain significant. METHODS: A retrospective observational study was conducted on 193 patients who were treated with LVHR by two minimally invasive surgeons in a 24-month period. The patient population was broadly divided into two groups based on the laparoscopic repair of the fascial defect with mesh underlay, or with primary suture repair and mesh underlay (PSR + MU). Patient demographics, rates of hernia recurrence, and other associated complications were compared between the two groups. Patient variables and the clinical outcomes were analyzed with descriptive statistics and chi-square test. RESULTS: One hundred ninety-three consecutive patients underwent LVHR for incisional (n = 136), umbilical (n = 44), epigastric (n = 9), and parastomal (n = 4) hernia. Hernia recurrence was documented in eight patients (4.1%). The mean follow-up period was 10.5 months (range 1-36 months). Incisional hernias accounted for all eight recurrences. The rate of recurrence in those treated with PSR + MU was 3% (two of 67 cases) in comparison with 4.8% (six of 126 patients) associated with mesh alone. The rate of recurrence in the recurrent hernia group, treated with mesh only, was 10.5% (four of 38 patients) compared with 4.8% (one of 21 patients) in the PSR + MU group. CONCLUSIONS: Primary laparoscopic repair along with mesh placement for the management of ventral hernia was found to be effective in selected cases as evidenced by the low rate of recurrence when compared with conventional laparoscopic repair with mesh alone. Further retrospective and prospective studies, with larger patient enrollment, are warranted to confirm the benefit of this technique over traditional repair.

Independent risk factors for infection in tissue expander breast reconstruction.

BACKGROUND: Postoperative infection in tissue expander breast reconstruction causes increased morbidity, cost, and suboptimal patient outcomes. To improve outcomes, it is important to preoperatively identify factors that might predispose to infection and minimize them when possible. It is hypothesized that certain patient characteristics are associated with an increased infection rate. METHODS: A retrospective, 6-year, single-institution review of patient records was performed from 413 tissue expanders placed in 300 women for postmastectomy breast reconstruction. Infection was defined as any case where antibiotics were given in response to clinical signs of infection. Fourteen potential risk factors were analyzed. A generalized estimation equations approach was used to perform univariable and multivariable analyses. RESULTS: Antibiotics were given to treat clinical infection in 68 of 413 expanders (16.5 percent), with a median time to diagnosis of 6.5 weeks (range, 1 to 52 weeks). Univariable analysis showed significant association with breast size larger than C cup (p < 0.001), previous irradiation (p = 0.007), repeated implant (p = 0.008), and delayed reconstruction (p = 0.04). All variables except delayed reconstruction remained significant (p < 0.002 for all) in a multivariable model. Additional significant covariates in this model included one surgical oncologist (p = 0.003) and contralateral surgery (p = 0.046). Given infection, one surgical oncologist was associated with an increased rate of mastectomy flap necrosis (p = 0.01). CONCLUSIONS: Certain patient characteristics are associated with increased infection in tissue expansion breast reconstruction. Understanding how these predispose to infection requires additional study. Patients identified with these characteristics should be educated about these risks and other reconstructive options to optimize the success of their breast reconstruction.

Barbed suture for gastrointestinal closure: a randomized control trial.

In an effort to make laparoscopic suturing more efficient, the V-Loc advanced wound closure device (Covidien, Mansfield, MA) has been produced. This device is a self-anchoring barbed suture that obviates the need for knot tying. The goal of this initial feasibility study was to investigate the use of the barbed suture in gastrointestinal enterotomy closure. A randomized study of 12 pigs comparing enterotomy closure with barbed versus a nonbarbed suture of similar tensile strength was performed. To this end, 25 mm enterotomies were made in the stomach (1 control, 1 treatment), jejunum (2 controls, 2 treatments), and descending colon (1 control, 1 treatment). Animals were killed at 3, 7, and 14 days postoperatively (4 each group) and their gastrointestinal tracts harvested; 6 of the 8 enterotomies from each pig underwent burst strength testing. The remaining 2 were fixed in formalin and sent for histological examination. All 12 pigs survived until they were killed without any major complications. Enterotomy closure with barbed suture revealed adhesion scores, burst strength pressures, and histology scores that were similar to those for the control. Jejunal closures resulted in 6 failures at 7 days (3 control, 3 barbed) and 4 failures at 14 days (2 control, 2 barbed). The barbed suture significantly reduced suturing time in the stomach, jejunum, and colon. The V-Loc wound closure device appears to offer comparable gastrointestinal closure to 3-0 Maxon while being significantly faster. Further studies with V-Loc are required to assess its use in laparoscopic surgery.

Pneumatosis coli in a dog.

A 17-year-old, castrated male Maltese was presented with chronic polyphagia and a 2-week history of tenesmus, diarrhea, hematochezia, weight loss, and ribbon-like feces. Pneumatosis coli was diagnosed by abdominal radiography. Concurrent hyperadrenocorticism was suspected. The clinical signs of colorectal disease resolved within 2 days of initiating a lowresidue diet and oral metronidazole. Pneumatosis coli should be considered as a differential diagnosis for colorectal disease in dogs.

Aryl hydrocarbon receptors in the frog Xenopus laevis: two AhR1 paralogs exhibit low affinity for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a potent developmental toxicant in most vertebrates. However, frogs are relatively insensitive to TCDD toxicity, especially during early life stages. Toxicity of TCDD and related halogenated aromatic hydrocarbons is mediated by the aryl hydrocarbon receptor (AhR), and specific differences in properties of the AhR signaling pathway can underlie in TCDD toxicity in different species. This study investigated the role of AhR in frog TCDD insensitivity, using Xenopus laevis as a model system. X. laevis, a pseudotetraploid species, expresses two distinct AhR1 genes, AhR1alpha and AhR1beta. Sharing 86% amino acid identity, these likely represent distinct genes, both orthologous to mammalian AhR and paralogous to the AhR2 gene(s) in most fish. Both AhR1alpha and AhR1beta exhibit TCDD-dependent binding of cognate DNA sequences, but they bind TCDD with at least 20-fold lower affinity than the mouse AhR(b-1) protein, and they are similarly less responsive in TCDD-induced reporter gene induction in conjunction with the mouse CYP1A1 promoter. Furthermore, CYP1A6 and CYP1A7 induction by TCDD in cultured X. laevis A6 cells appears much less responsive than CYP1A induction in cell lines derived from more sensitive animals. Taken together, these data suggest that low affinity binding by X. laevis AhRs plays an important mechanistic role in the insensitivity of frogs to TCDD. An understanding of these molecular mechanisms should aid amphibian ecotoxicology and refine the use of frog embryos as a model [e.g. in FETAX (Frog Embryo Teratogenesis Assay-Xenopus)] for determining developmental toxicity of samples containing dioxin-like compounds.