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Tissue function and homeostasis reflect the gene expression signature by which the combination of ubiquitous and tissue-specific genes contribute to the tissue maintenance and stimuli-responsive function. Enhancers are central to control this tissue-specific gene expression pattern. Here, we explore the correlation between the genomic location of enhancers and their role in tissue-specific gene expression. We find that enhancers showing tissue-specific activity are highly enriched in intronic regions and regulate the expression of genes involved in tissue-specific functions, whereas housekeeping genes are more often controlled by intergenic enhancers, common to many tissues. Notably, an intergenic-to-intronic active enhancers continuum is observed in the transition from developmental to adult stages: the most differentiated tissues present higher rates of intronic enhancers, whereas the lowest rates are observed in embryonic stem cells. Altogether, our results suggest that the genomic location of active enhancers is key for the tissue-specific control of gene expression., (© 2021 Borsari et al.; Published by Cold Spring Harbor Laboratory Press.)

Objective: The Training Interventions and Genetics of Exercise Response (TIGER) study is an exercise program designed to introduce sedentary college students to regular physical activity and to identify genetic factors that influence response to exercise., Participants: A multiracial/ethnic cohort (N = 1,567; 39% male), age 18 to 35 years, participated in the study., Methods: Subjects underwent 30 weeks of exercise training, 3 days/week, for 40 minutes at 65% to 85% of age- and gender-predicted maximum heart rate reserve. Multiple measures of body size/composition, heart rate, and blood pressure were obtained., Results: A total of 1,567 participants, (39% male), age 18 to 35 years, participated in the TIGER study. The prevalence of overweight/obesity in participants was 48.0%/19.3% in non-Hispanic Whites, 55.3%/24.2% in Hispanic Whites, 54.9%/25.4% in African Americans, and 38.3%/11.3% in Asians. Average within-semester retention was 68%, but overall retention (30 weeks, 2 semesters) was 20%., Conclusions: The TIGER study represents an efficacious strategy for introducing college-aged individuals to regular aerobic exercise.

In recent years, significant evolutionary changes in the management of the aging face have occurred. These changes have resulted in dramatic improvements, not only in aesthetic results but also in longevity. This article attempts to collate these changes into a modern rhytidectomy technique.

Cosmetically, the optimal management of the amputated external ear is microsurgical replantation. Although technically demanding, replantation is possible by the experienced surgeon. Success frequently requires the use of vein grafts, heparinization, and the alleviation of venous congestion with medicinal leeches or frequent stab wounds.

Injuries to the inferior vena cava are being seen with increasing frequency in the civilian population. A review of the experience at UCLA/Harbor General Hospital Medical Center over a ten year period (1966 to 1976) discloses thirty-four patients with major injuries to the inferior vena cava, with an overall mortality of 53%. The factors that appear critical to patient survival are: (1) level of injury (suprarenal versus infrarenal sites); (2) presence or absence of profound shock on admission; and (3) the speed with which diagnosis is made and treatment carried out. Technical considerations regarding identification and handling of inferior vena caval injuries are presented. The mortality rate for major inferior vena caval injuries remains distressingly high and serves as a challenge for future improvement.

This paper presents the fifth reported case of replantation of a traumatically amputated ear and its management. The ear was amputated in an automobile accident and was revascularized microsurgically. Replantation, when possible, offers the ultimate result; however, shortcomings include the length of operation, prolonged hospitalization, and postoperative management of venous congestion.

Nine flaps for reconstructing pelvic wounds were centered on the posterior portion of the thigh over the inferior gluteal artery and posterior cutaneous nerve of the thighs of seven patients. No flap necrosis occurred and all wounds healed (one hematoma and one partial wound separation). Three patients had radiation wounds and three had immediate reconstruction following tumor resection. This flap represents an important advance in pelvic reconstruction and should be considered the flap of choice for this area. Contributions to the procedure from this series include (1) use in vaginal reconstruction, (2) length of flap extended to the popliteal fossa, and (3) use of an air-fluidized bed for postoperative management.

In each of 2 recent patients with distant pedicles (one a groin flap and the other a cross-leg flap), we were able to perform the final division and detachment of the flap on the fifth postoperative day. Cross-clamping was used to create intermittent periods of ischemia. The periods of ischemia were progressively increased until the time of division. Fluorometry with intravenous fluorescein played a role in deciding when to divide the flap. The patients were discharged from the hospital on the sixth and seventh days, respectively. Trimming was done on an outpatient basis.

No congenital malformation in infants is more profound than anterior craniofacial duplication. The precise term for this rare anomaly is diprosopus, referring to a fetus with a single trunk, normal limbs, and varying degrees of facial duplication. A search of the world literature produced only 16 cases of diprosopus since 1864. Despite the rarity of this anomaly, three such infants were born in the Southern California area during the past year, making this the largest reported series to date. The three infants were born with two distinctly formed faces. Each had four separate eyes, two mouths, two noses, and two ears with a primitive ear or sinus tract at the plane of fusion. In addition, multiple congenital aberrations existed which involved a variety of internal organs. The pathogenesis of diprosopus is not well understood, but environmental stress early in embryologic development has been suggested as a possible factor. The apparent mechanism is a slowing of pregastrulation oxidation with resultant focal developmental arrests.

Malignant hyperthermia is a threat to the life of the surgical patient. It is a pharmacogenic disease that is brought on by contact with certain drugs and is manifest by a hypermetabolic crisis with tachycardia, ventricular ectopy, metabolic acidosis, and a rapid rise in body temperature. Muscle rigidity may or may not be present. Thanks to a reliable porcine animal model of malignant hyperthermia, dantrolene sodium has been found to be effective in the prevention and treatment of malignant hyperthermia. In this article a case report of malignant hyperthermia occurring in an office surgery suite is presented. The patient was 37 years old and underwent a routine septorhinoplasty under general anesthesia. The operation was complicated by ventricular ectopy, rapid rise in body temperature, and muscle rigidity at the end of the case. The malignant hyperthermia aborted spontaneously after 30 minutes; dantrolene was not given.

We present three cases of severe external ear injuries and their management. The first patient's ear, amputated in an automobile accident, was revascularized microsurgically. Replantation, when possible, offers the ultimate result. However, disadvantages include the length of the operation and prolonged hospitalization. The second patient sustained a human bite ear amputation. Salvage consisted of immediate coverage with a vascularized temporoparietal fascial flap and split-thickness skin graft. Revision of the external auditory meatus and postauricular sulcus was required. This technique is relatively simple and reliable when microvascular revascularization is not possible. In the third case the patient's ear suffered a full-thickness burn as part of a larger scalding injury to the patient's body, face and scalp. Acute salvage was accomplished in one stage with a technique similar to that used for the second patient. Secondarily, skin was regrafted to achieve an improved color match and cartilage contour.