The effect of small bowel bypass and subsequent resection on gastric acid secretion and serum gastrin

Evaluation of gastric acid secretion and serum gastrin response to proximal or distal intestinal bypass and subsequent resection was undertaken. Ten dogs with gastric fistulas underwent control secretory studies consisting of basal acid output (BAO), maximal vagal stimulation (2 deoxy-d-glucose (2DG) 150 mg/kg iv), maximal histamine stimulation (160 μg/kg/hr iv), and test meal stimuli. Serum gastrin was measured basally and following gastric stimulation. Dogs were then divided into two bypass groups: Group I, distal bypass, leaving 40 cm jejunum and 4 cm ileum; and Group II, proximal bypass, leaving 4 cm jejunum and 40 cm ileum. Postoperatively, repeat studies were performed. Both groups then underwent resection of the bypassed segments followed by repeat secretory and gastrin tests. BAO was significantly increased in Group I dogs. BAO increased from a control of 0.04 ± 0.02 to 0.51 ± 0.19 meq H⁺/60 min (±SEM). No significant changes in BAO were observed in Group II following bypass. Acid secretion to maximal vagal or maximal histamine stimulation was not significantly different in either group. Serum gastrin response was unchanged in either group following a test meal. In Group I dogs, resection of the previously bypassed bowel produced a further significant increase in BAO (1.44 ± 0.4 meq H⁺/60 min). After resection of the bypassed bowel, there was no significant change in basal or stimulated gastrin. Gastric fistula BAO increased following 90% distal but not proximal bypass; subsequent resection of the bypassed segment produced a further increase in BAO. Acid secretory responses to both histamine and 2DG were not influenced by either bypass or resection. An increase in BAO without a change in the background of serum gastrin may suggest the presence of a gastric secretory inhibitor in the distal small bowel.     

Hemoglobin solution: Is a normal [Hb] or P50 more important?

Although stroma-free hemoglobin solution (SFH) supports normal levels of oxygen consumption in baboons exchange transfused to zero hematocrit, a significant decrease occurs in the mixed venous oxygen tension ($\text{P}\text{v}\text{O}{}_2$). The hemoglobin concentration (6–8 g%) and P₅₀ (12–17 Torr) are both low in the current SFH preparations, and it is likely that they contribute to the low $\text{P}\text{v}\text{O}{}_2$ values. A multiple linear regression analysis was used to quantitate the contribution of simultaneous changes in [Hb] and P₅₀ to the observed change in $\text{P}\text{v}\text{O}{}_2$ during total exchange transfusion with SFH. During the study the average $\text{P}\text{v}\text{O}{}_2$ decreased from 51.4 to 22.4 Torr; the [Hb] fell from 11.6 to 5.1 g%; and the P₅₀ decreased from 31 to 19.5 Torr. The resulting equation was $\text{P}\text{v}\text{O}{}_2\text{= 4.0[}\text{Hb}\text{] + 0.33 P}{}_{50}\text{- 4.2}$. The equation calculates that the 6.5 g% decrease in [Hb] was responsible for a fall in $\text{P}\text{v}\text{O}{}_2$ of 26 Torr, while the fall in P₅₀ of 11.5 Torr decreased the $\text{P}\text{v}\text{O}{}_2$ only 3.8 Torr. The data suggest that an increased [Hb] should be more effective in raising $\text{P}\text{v}\text{O}{}_2$ than a higher P₅₀. Since a low $\text{P}\text{v}\text{O}{}_2$ is an indication of a reduced oxygen reserve, future efforts should attempt to achieve a hemoglobin solution with a normal [Hb].     

Tracking respiratory therapy in the trauma patient

The respiratory index (RI), $\text{P(AaDO}{}_2\text{)}\text{PaO}{}_2$, was investigated in a retrospective study of 177 intubated patients treated at the Maryland Institute for Emergency Medicine. An RI of 0.1 to 0.37 is normal. Patients with an RI of 2 or greater were intubated. Those patients who reached an RI of 6 or more had an associated 12 per cent probability of survival. The RI reflects the presence of pulmonary shunting in a variety of circumstances including atelectasis, pulmonary contusion, and pulmonary emboli.A nomogram that allows the course of the patient with respiratory problems to be followed is described. Movement along the same isobars or between isobars can be followed by plotting the PaO₂ against the F_IO2. Thus, the rationale and effect of respiratory therapeutic manipulations may be recorded graphically.     

HIV-1 Protein gp120 Induces Mouse Lung Fibroblast-to-Myofibroblast Transdifferentiation via CXCR4 Activation

BackgroundIndividuals with HIV have ～2-fold increased risk of developing pulmonary fibrosis. The mechanism(s) by which this occurs has yet to be determined. HIV-1 protein gp120 activates CXCR4 in the lymphocyte, promoting a variety of intracellular signaling pathways including those common to TGFβ1 associated with lung fibroblast-to-myofibroblast transdifferentiation. We hypothesized that gp120 promotes pulmonary fibrotic changes via activation of CXCR4 in the lung fibroblast.MethodsMouse primary lung fibroblasts (PLFs) were cultured ± gp120, then analyzed for α-SMA expression and stress fiber formation. In parallel, PLFs were cultured ± gp120 ± AMD3100 (a CXCR4 antagonist), and α-SMA, pan and phospho-Akt, and total and phospho-MAPK (or ERK1/2) protein expression was quantified. Finally, lungs and PLFs from wild-type and HIV-1 transgenic mice were analyzed for hydroxyproline and α-SMA content.Resultsgp120 treatment increased α-SMA expression and myofibroblast differentiation in PLFs. gp120 treatment activated phosphorylation of ERK1/2, but not PI3K-Akt. Pretreatment with AMD3100 inhibited gp120-induced ERK1/2 phosphorylation and gp120-induced α-SMA expression. In parallel, there was a significant increase in hydroxyproline content in lungs from older HIV-1 transgenic mice and a >3-fold increase in α-SMA expression in PLFs isolated from HIV-1 transgenic mice.Conclusionsgp120 induces α-SMA expression and fibroblast-to-myofibroblast transdifferentiation by activating the CXCR4-ERK1/2 signaling pathway in mouse PLFs. Lungs of older HIV-1 transgenic mice contain higher hydroxyproline content and their PLFs have a striking increase in α-SMA expression. These results suggest a mechanism by which individuals with HIV are at increased risk of developing pulmonary fibrotic changes as they age.     

Ethylene glycol poisoning

In 1960 ethylene glycol poisoning accounted for 40 to 60 deaths per year in the United States, and the ingestion of this compound remains a major cause of drug poisoning. The clinical manifestations have been well recorded and consist of central nervous system dysfunction with severe metabolic acidosis, cardiopulmonary failure and acute renal failure.Until recently, however, the pathogenesis of the clinical manifestations has remained uncertain. We report a case of severe ethylene glycol poisoning and review recent studies which have clarified much of the biochemistry of ethylene glycol metabolism. Based on a better understanding of the attendant biochemical derangements, it is now possible to explain much of the pathophysiology of ethylene glycol poisoning and to outline a rational mode of management.     

Subtotal cholecystectomy for the hostile gallbladder: failure to control the cystic duct results in significant morbidity

Background

Outcomes following the inability to control the cystic duct due to a hostile triangle of Calot during cholecystectomy remain unknown. The purpose of this study was to analyze the safety and efficacy of subtotal cholecystectomy, with attention to the necessity for secondary interventions.

Novel light treatment for digital ulcers in systemic sclerosis: a feasibility study

Background

Locally acting, well-tolerated treatments for digital ulcers in patients with systemic sclerosis are needed. We aimed to investigate the safety, feasibility, and tolerability of a novel light treatment, and to tentatively assess treatment efficacy.

Operative morbidity and survival following hepatectomy for colorectal liver metastasis in octogenarians: a contemporary case matched series

Background

Clinical outcomes of octogenarians undergoing hepatectomy for colorectal liver metastases (CRLM) are poorly characterized. The current study evaluated operative morbidity, mortality and survival outcomes among a contemporary cohort of octogenarians.