Probiotic Studies in Neonatal Mice Using Gavage.

Adult mouse models have been widely used to understand the mechanism behind disease progression in humans. The applicability of studies done in adult mouse models to neonatal diseases is limited. To better understand disease progression, host responses and long-term impact of interventions in neonates, a neonatal mouse model likely is a better fit. The sparse use of neonatal mouse models can in part be attributed to the technical difficulties of working with these small animals. A neonatal mouse model was developed to determine the effects of probiotic administration in early life and to specifically assess the ability to establish colonization in the newborn mouse intestinal tract. Specifically, to assess probiotic colonization in the neonatal mouse, Lactobacillus plantarum (LP) was delivered directly into the neonatal mouse gastrointestinal tract. To this end, LP was administered to mice by feeding through intra-esophageal (IE) gavage. A highly reproducible method was developed to standardize the process of IE gavage that allows an accurate administration of probiotic dosages while minimizing trauma, an aspect particularly important given the fragility of newborn mice. Limitations of this process include possibilities of esophageal irritation or damage and aspiration if gavaged incorrectly. This approach represents an improvement on current practices because IE gavage into the distal esophagus reduces the chances of aspiration. Following gavage, the colonization profile of the probiotic was traced using quantitative polymerase chain reaction (qPCR) of the extracted intestinal DNA with LP specific primers. Different litter settings and cage management techniques were used to assess the potential for colonization-spread. The protocol details the intricacies of IE neonatal mouse gavage and subsequent colonization quantification with LP.

Visual deficit interventions in adult stroke and brain injury: a systematic review.

Visual deficits after cerebral injury are common. The variability in the types of injury sustained as well as their impact on function in the environment have produced multiple approaches at corrective intervention. To assess the effectiveness of these vision interventions, an extensive literature search was completed. The analysis of this review revealed some success with visual neglect disorders, but not enough evidence to comment definitively on interventions for hemianopsia, quadrantonopsia, diplopia, or convergence insufficiency. A lack of follow-up also limited efforts to assess the durability of documented gains. Additional research is necessary to clarify, quantify, and measure treatment outcomes for acquired visual dysfunction as well as to link laboratory testing to improvement in actual functioning for individuals in their environment.

The treatment of alkaline burns of the skin by neutralization.

Literature reports dating as far back as 1927 have lured clinicians into the belief that alkaline skin burns are best treated by water dilution and that neutralization attempts should be avoided. Although this belief has never been substantiated, neutralization of an alkaline burn of the skin with acid was thought to increase tissue damage secondary to the exothermic nature of acid-base reactions. The authors proposed that topical treatment of alkaline burns with a weak acid such as 5% acetic acid (i.e., household vinegar) would result in rapid tissue neutralization and reduction of injury in comparison to water irrigation alone. In a rat skin burn model, animals were exposed to an alkaline injury when filter paper (2 cm in diameter) saturated with 2N sodium hydroxide was placed over the volar aspect of the animal for a period of 1 minute. Treatment was initiated 1 minute after injury and included either neutralization with a 5% acetic acid solution (n = 8) or irrigation (n = 8) with water. Skin temperature and pH were monitored using subdermal needle probes until the pH of the skin returned to physiologic values. Punch-biopsy specimens were obtained from the wound edges 24 hours after injury to assess burn depth and leukocyte infiltration, and biopsies were repeated 10 days later to assess wound healing. The authors proposed that neutralization of an alkaline substance with household vinegar (i.e., 5% acetic acid solution) would result in rapid neutralization and thus reduce extent of tissue injury. Animals treated with acetic acid demonstrated a more rapid return to physiologic pH (14.69 +/- 4.06 minutes versus 31.62 +/- 2.83 minutes; p < 0.001), increased depth of dermal retention (0.412 +/- 0.136 mm versus 0.214 +/- 0.044 mm; p = 0.015), decreased leukocyte infiltrate (31.0 +/- 5.1 cells/high-power field versus 51.8 +/- 6.8 cells/high-power field; p < 0.001), and improved epithelial regeneration (4.0 +/- 0.6 cell layers versus 1.7 +/- 0.5 cell layers; p < 0.001) when compared with animals treated with water irrigation. No difference was detected in peak pH (10.35 +/- 0.28 pH versus 10.36 +/- 0.25 pH; p = 0.47) nor in rise of skin temperature (maximum temperature, 32.8 degrees C versus 32.9 degrees C; p = 0.33) between acetic acid-neutralized and water-irrigated burn wounds. The observed benefits of treating alkaline burns with 5% acetic acid in the rat model are significant and require clinical testing.

Laparoscopic ligation of the thoracic duct in management of chylothorax.

Laparoscopic ligation of the cisterna chyli at the level of the aortic hiatus was performed in a 69-year-old woman with post-lobectomy chylothorax refractory to 3 weeks of conservative therapy and one repeat thoracotomy with attempted ligation of a leaking lymphatic channel. This laparoscopic procedure was successful, and resolution of the chylothorax was achieved. We feel that this technique offers surgeons a valid, minimally invasive treatment option for a persistent chylothorax in which conservative management or more direct thoracic procedures have failed to control the chyle leak.