Association between estimated pulse wave velocity and in-hospital mortality of patients with acute kidney injury: a retrospective cohort analysis of the MIMIC-IV database

BACKGROUND

Estimated pulse wave velocity (ePWV) has been found to be an independent predictor of cardiovascular mortality and kidney injury, which can be estimated noninvasively. This study aimed to investigate the association between ePWV and in-hospital mortality in critically ill patients with acute kidney injury (AKI).

METHODS

This study included 5960 patients with AKI from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The low and high ePWV groups were compared using a Kaplan-Meier survival curve to evaluate the differences in survival status. Cox proportional hazards models were used to explore the association between ePWV and in-hospital mortality in critically ill patients with AKI. To further examine the dose-response relationship, we used a restricted cubic spline (RCS) model. Stratification analyses were conducted to investigate the effect of ePWV on hospital mortality across various subgroups.

RESULTS

Survival analysis indicated that patients with high ePWV had a lower survival rate than those with low ePWV. Following adjustment, high ePWV demonstrated a statistically significant association with an increased risk of in-hospital mortality among AKI patients (HR = 1.53, 95% CI = 1.36-1.71, p < 0.001). Analysis using the RCS model confirmed a linear increase in the risk of hospital mortality as the ePWV values increased (P for nonlinearity = 0.602).

CONCLUSIONS

A high ePWV was significantly associated with an increased risk of in-hospital mortality among patients with AKI. Furthermore, ePWV was an independent predictor of in-hospital mortality in critically ill patients with AKI.

Coix lacryma-jobi Seed Oil Reduces Fat Accumulation in Nonalcoholic Fatty Liver Disease by Inhibiting the Activation of the p-AMPK/SePP1/apoER2 Pathway

The lipid metabolism disorder is the key role of Nonalcoholic fatty liver disease (NAFLD). Selenoprotein P plays an important role in the pathological process of lipid accumulation. Coix lacryma-jboi seed oil (CLSO) is an active component extracted from Coix lacryma-jobi seed (CLS) which has been found to be effective of reducing blood fat and antioxidative. But the effect and mechanism of CLSO on NAFLD are not clear. The aim of this study was to explore the therapeutic effect and mechanism of CLSO in the treatment of NAFLD. Our result showed that CLSO decreased the liver/body weight ratio, lowered the total cholesterol (TC) and triacylglycerol (TG), and elevated the high density lipoprotein (HDL) in serum. CLSO reduced the lipid deposition in the liver of NAFLD rats. In addition, CLSO could bring down the abnormal expression of superoxide dismutase (SOD) and malondialdehyde (MDA). Moreover, CLSO significantly declined the liver apolipoprotein E (apoE), apolipoprotein E receptor (apoER) and selenoprotein P 1 (SePP1) expression. In vivo, CLSO decreased the lipid droplets and TG level, reduced the protein expression of SePP1, apoER, phosphor-adenosine 5'-monophosphate (AMP)-activated protein kinase (p-AMPK) in the cytoplasm of HepG2 cells induced by oleic acid and palmitic acid (OP). At the same time, lipid accumulation was observed in the Sepp1 high expression cells induced by endoplasmic reticulum (ER) activator tunicamycin (Tm). CLSO could identically reduce the protein expression of SePP1, apoER, p-AMPK in the cytoplasm of HepG2 cells induced by Tm. This result not only proved the CLSO had therapeutic effect on NAFLD, but also confirmed its mechanism associated with degrading the phosphorylation of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) which led to the decrease of the expression SePP1/apoER2 in order to reduce lipid accumulation. The study suggests CLSO has great medicinal value in treating NAFLD besides its edibility.

The evaluation of long-term effects of ionizing radiation through measurement of current sister chromatid exchange (SCE) rates in radiology technologists, compared with previous SCE values

Ionizing radiation is a strong physical mutagen, causing breakage of phosphodiester bonds in DNA at any stage of the mitotic cycle. Analysis of sister chromatid exchange (SCE) has come into use as a sensitive DNA-damage indicator. We investigated the SCE rates in radiology technologists who are occupationally and chronically exposed to ionizing radiation. The study included 39 radiology technologists and 35 sex- and age-matched healthy controls. There was a statistically significant difference in the SCE frequency between radiology technologists and controls (p<0.0001). Additionally, previous SCE data of 10 radiology technologists were compared with current results regarding radiation exposure time. There was statistically significant difference between previous and current SCE values (p=0.005). The significant increase in the frequency of SCE in radiology technologists emphasizes the importance of radiation-protection procedures in order to minimize radiation exposure and avoid possible genotoxic effects. Comparison of two studies that measured SCE values of radiology technologists after 8 years also suggests that the genotoxic effect is reversible. In conclusion, radiation is still an important mutagenic agent despite improvements in daily working hours and conditions.

Effect of IGF-1R inhibitor BMS-754807 on tumor glucose metabolism and proliferation in Sal-IGF xenografts by FDG and FLT- PET imaging

e14501

Background: The type 1 insulin-like growth factor receptor (IGF-1R) plays a critical role in mitogenesis and survival in a variety of human tumor cells. IGF-1R is also closely related to the insulin receptor (IR). It is becoming increasingly evident that stimulation of IR or IR/IGF-1R hybrid receptors by insulin or IGF-1/2 may contribute to cancer growth, suggesting that both IGF-1R and IR may be targets for cancer therapy. BMS-754807 (‘807) is an oral IGF-1R tyrosine kinase antagonist under development that also blocks IR activity. This study explores the feasibility of fluorodeoxyglucose (FDG) and fluorothymidine (FLT) positron emission tomography (PET) as pharmacodynamic imaging biomarkers in a xenograft model. Methods: Mice were implanted with fragments of Sal-IGF, a transgenic salivary gland tumor expressing constitutively active IGF-1R. Once tumors reached desired size, the mice were divided into 3 treatment groups (vehicle, 6.25 mg/kg ‘807, & 50 mg/kg ‘807 on days 1–4). FDG-PET scans were performed on day -2 (prior to treatment), days 1 & 2 (max/min concentrations post day 1 dose), and days 4 & 5 (max/min day 4 dose). FLT-PET scans were performed on days -2, 2 (min day 1 dose), & 5 (min day 4 dose). Results: With FDG-PET imaging, a 66% reduction (P<0.05, paired t-test) in tumor SUVmean was observed at the end of the 50 mg/kg therapy (day 4) and sustained for 24h (day 5) with a concomitant reduction of 37% in tumor burden by day 5 (P<0.05). FLT-PET studies demonstrated a 45% reduction (P<0.05) in tumor SUVmean observed 24h after the end of 50 mg/kg therapy (day 5) with a concomitant reduction of 50% in tumor burden (day 5, P<0.05). Conclusions: Correlation with tumor growth inhibition suggests feasibility of FDG- PET despite IR blockade. These results support the use of both FDG and FLT PET imaging in clinical trials with ‘807.

[Table: see text]

Transposition of great arteries in an infant born after prenatal diagnosis of trisomy 20 mosaicism

We report a case of prenatally diagnosed mosaic trisomy 20 in cells cultured from amniotic fluid. Trisomy 20 was present in 7 cells (13 percent) in a total of 52 investigated cells. Following the normal findings of an ultrasound scan, the couple decided to continue the pregnancy. A dysmorphic infant was born at the 38 weeks of gestation with generalized dysmorphic features and multiple cardiac anomalies including transposition of great arteries. Chromosome analysis on both cord blood and placenta at birth revealed a normal 46,XX karyotype. This patient is the first case of a liveborn infant with mosaic trisomy 20 cells detected in amniotic fluid culture with transposition of great arteries, atrioventricular concordance and ventricoarterial discordance.

A boy with small supernumerary marker chromosome X identified by FISH

Marker or ring X chromosomes are frequently seen in Ullrich-Turner Syndrome with 46,X,r(X) karyotype, but only 8 children were reported with an extra marker X chromosome in at least some of their cell lines, we describe a 5 years old male patient who is mosaic (17%) for a cell line with an extra ring shaped marker X chromosome in addition to a normal 46,XY cell line. He had mild motor mental retardation, a dysmorphic face, dysplastic ears, high arched palate, cryptorchidism and brachydactyly. G-banding showed 46,XY[83]/47,XY,+r?[17] karyotype. NOR banding revealed no satellite region but its centromere was intact in C-banding. By fluorescent in situ hybridization (FISH) technique, dual X/Y alpha-satellite probes were used to detect the origin of ring shaped marker chromosome and 17% of his cells had two X chromosome signals due to marker X; hybridization with X chromosome inactivation center (XIST) specific probe revealed the absence of the locus on the ring chromosome. In this report, clinical features of our patient are compared with previously reported cases and the cytogenetic and molecular cytogenetic techniques used to detect origin of marker chromosome are discussed.

Two complementary recombinant chromosomes 5 in a healthy woman

We report a healthy woman with two abortions who is a carrier for a rare heterozygous double recombinant of an inv(5) chromosome, karyotype 46,XX,rec(5)dup(5p) inv(5)(p13q22),rec(5)dup(5q)inv(5)(p13q22). Her father had a 46,XY,inv(5)(p13q22) karyotype; his consanguineous wife had died. Molecular investigation of 11 highly polymorphic markers spanning chromosome 5 revealed biparental inheritance for two markers (D5S406, D5S681) on 5p15.3 and 5q13.1, and an allele constellation not compatible with paternal heterodisomy for marker D5S623 on 5q11.2. Eight markers were not informative. Three mechanisms of formation are proposed: First, fertilization of a normal oocyte by a sperm carrying the two recombinant chromosomes 5, followed by postzygotic recombination between the normal maternal homologue and the rec(5)dup(5p), and by loss of the mitotically recombined maternal homologue, leading to segmental paternal heterodisomy 5q13-->qter (trisomic rescue). Second, postzygotic recombination in a 46,XX,inv(5)(p13q22) zygote resulting in the 46,XX,rec(5)dup(5p)inv(5)(p13q22),rec(5) dup(5q)inv(5)(p13q22) karyotype, followed by absence of the original cell line in lymphocytes. Third and most likely, both parents were inv(5) carriers and complementary recombinations in maternal and paternal meiosis resulted in a zygote with two recombinant chromosomes 5. Our patient refused any further studies but later reported the birth of a phenotypically normal child. This is the first report known to us of complementation by two non-homologous recombinant chromosomes in a phenotypically normal woman, and the first example of a child born to a carrier of complementary recombinant chromosomes.

Preclinical efficacy evaluation of ixabepilone (BMS-247550) in combination with cetuximab or capecitabine in human colon and lung carcinoma xenografts

12017

Background: Ixabepilone belongs to a class of structurally novel, microtubule-stabilizing agents that exert their antimitotic action by binding to tubulin with a binding mode that is distinct from the taxanes. Preclinical findings that ixabepilone has antitumor activity in a broad spectrum of tumor types, including taxane-resistant tumors, is borne out by Phase II clinical trials where ixabepilone has demonstrated activities in multiple tumor types including breast, renal, pancreatic, prostate and lymphoma. The aim of this series of studies was to further characterize the therapeutic potential of ixabepilone in combination with currently approved chemotherapy agents. Methods: Antitumor activity was evaluated in the GEO human colon and L2987 human lung carcinoma xenografts. Therapeutic synergism of the combination was defined as the attainment of efficacy that was significantly better than the best response of the individual single agents administered at their maximum-tolerated dose (MTD) or optimal dose (OD). Results: In the GEO tumors, single-agent ixabepilone produced 1.1 log cell kill (LCK) at its MTD. Cetuximab at its OD yielded 0.8 LCK. The combination of ixabepilone and cetuximab produced 1.7 LCK which was significantly superior to ixabepilone alone (P=0.0173) and cetuximab alone (P=0.0002). Similar synergistic efficacy was observed in the L2987 tumors. The combined efficacy of capecitabine plus ixabepilone was evaluated in the GEO tumors. In this tumor, single-agent ixabepilone was modestly active (LCK = 0.8) at its MTD. Single-agent capecitabine was not effective (LCK = 0.4) at its MTD. However, the combination of the two agents produced therapeutic synergism, yielding antitumor efficacy (1.9 LCK) that was superior to either of the agents alone at their MTDs (P=0.035 and 0.0004, respectively). Conclusions: Ixabepilone demonstrates robust synergistic antitumor efficacy when used in combination with cetuximab or capecitabine in human xenografts providing a biologic rationale for these combinations in the treatment of cancer.

[Table: see text]

A case with mosaic partial duplication of 1q: prenatal and postmortem clinical and cytogenetic evaluations

Partial trisomy 1q including different segments of the long arm is a rare cytogenetic anomaly. Especially the cases with mosaic proximal tandem duplication of 1q included a longer fragment are very rare. Cases who have partial 1q trisomy showed large phenotypic variation due to the differences in size of the duplicated segments of 1q. The clinical phenotype of most cases is characterized by multiple congenital anomalies especially including central nervous system and developmental delay. We describe a prenatally diagnosed case with mild cerebral ventriculomegaly and karyotype with mosaic pure trisomy of chromosome 1q [(46,XX/46,XX,dup(1)(q21qter)]. Phenotypic postmortem examination showed cranial asymmetry, flat and broad nasal bridge, anteverted nostrils, hypertelorism, retrognathia, abnormal pinnae, hypoplasic thumbs, long fingers and toes, mediodorsal curvature of the 4th and 5th toes and posterior prominence of the heel was observed. Autopsy confirmed the ventriculomegaly. Postmortem chromosome preparation from skin culture, cord blood and intracardiac blood confirmed the mosaic pure trisomy of chromosome 1q.

Correlation of pharmacokinetics with the antitumor activity of Cetuximab in nude mice bearing the GEO human colon carcinoma xenograft

PURPOSE

The epidermal growth factor receptor (EGFR), a protein tyrosine kinase expressed in many types of human cancers including colon and breast, has been strongly associated with tumor progression. Cetuximab, an IgG1 anti-EGFR chimeric mouse/human monoclonal antibody, has been proven to be effective in the treatment of advanced colon cancer. To date, there has not been a study to systematically evaluate the pharmacokinetics (PK) of Cetuximab in a preclinical model and to further explore any correlation of drug exposure between animal models and cancer patients. In the present study, we characterized the PK of Cetuximab in nude mice at efficacious dose levels and further compared the preclinical optimal dose and active plasma drug concentration with those determined in clinical studies.

EXPERIMENTAL DESIGN

The antitumor activity of Cetuximab was evaluated using the GEO human colon carcinoma xenografts implanted subcutaneously in nude mice. The drug was administered ip every 3 days for five total injections (inj) (q3dx5) at dose levels ranging from 1 mg/inj to 0.04 mg/inj. The plasma PK of Cetuximab was determined at dose levels of 1.0, 0.25, and 0.04 mg/inj with a single bolus iv or ip administration in nude mice. The tumoral PK of Cetuximab was determined at dose levels of 0.25, and 0.04 mg/inj with a single bolus ip administration in nude mice bearing GEO tumor xenografts. The plasma and tumoral levels of Cetuximab were quantitated by an ELISA assay.

RESULTS

Cetuximab demonstrated a dose-dependent antitumor activity at dose levels of 0.25, 0.1, and 0.04 mg/inj, with a statistically significant tumor growth delay (in reaching a tumor target size of 1 gm) of 18 days (P < 0.001), 12.3 days (P < 0.01), and 10 days (P < 0.01) for 0.25, 0.1, and 0.04 mg/inj, respectively. A separate study employing the same treatment schedule showed that Cetuximab was equally active at dose levels ranging from 0.25 mg/inj to 1 mg/inj. Therefore, dose levels of Cetuximab from 1 mg/inj to 0.04 mg/inj can be considered to be within the efficacious range, while dose levels of 0.25 mg/inj or higher appeared to be optimal for the antitumor activity of Cetuximab in the GEO tumor model. When Cetuximab was given iv to mice, the elimination half life (t(1/2)) was 39.6, 37.8, and 42.2 h for doses of 1.0, 0.25, and 0.04 mg/inj, respectively, suggesting a similar disposition kinetics of Cetuximab within this dose range. The volume of distribution (V(d)) ranged from 0.062 l/kg to 0.070 l/kg, suggesting that Cetuximab is primarily confined to the plasma compartment with limited peripheral tissue distribution. Clearance (CL) was similar and no apparent PK saturation was observed across the dose ranging from 0.04 mg/inj to 1.0 mg/inj. When mice were administered with a single bolus ip administration at doses of 1, 0.25, and 0.04 mg/inj, the maximum plasma concentration (C(max)) was 407.6, 66.4, and 16.5 microg/ml. The area under the curve of plasma drug concentration (AUC) was 19212.4, 3182.4, and 534.5 microg/ml h, for 1.0, 0.25, and 0.04 mg/inj, respectively. The average steady state plasma concentration (C(ss avg)) for the multiple dosing schedule was estimated to be 73.1 microg/ml at 0.25 mg/inj and was considered as an active plasma drug concentration. The maximum tumoral concentration of Cetuximab was 2.6 and 0.53 ng/mg-tumor while the tumoral drug exposure was 112.6 and 18.3 ng/mg h for 0.25 and 0.04 mg/inj, respectively. The EGFR was estimated to be nearly completely occupied by Cetuximab at the optimal dose of 0.25 mg/inj.

CONCLUSION

In the present study, we compared the preclinical optimal dose and the corresponding active plasma concentration determined in mice with those being observed in cancer patients, i.e. 65-100 microg/ml. The preclinical optimal dose of 0.25 mg/inj was significantly lower than the current clinical dose. However, the active plasma concentration at 0.25 mg/inj is within the range of the active drug concentrations in cancer patients treated with Cetuximab under the current optimal dosing regimen. It appears that the active plasma drug concentration determined in preclinical model predicts better than the optimal preclinical dose for the clinical development of antibody drugs.

Haplotype block definition and its application

We present a simple two-stage procedure to define haplotype blocks and construct a statistic to test whether a polymorphism belongs to a block. Applying this method to the data of Gabriel et al. [2002] yielded longer haplotype blocks than were originally reported with a similar average percentage of common haplotypes in blocks. Furthermore, across regions of the genome and among the four populations that were studied, we found that linkage disequilibrium between a given single nucleotide polymorphism (SNP) and the haplotype block was a monotonic function of distance. This correlation was essentially independent of the minor allele frequency of the putative causal SNP when it fell outside of the block, however it was strongly dependent on the minor allele frequency when the SNP was internal to the block. These results have direct application to the design of candidate gene or region-wide association studies.

Planar LiTaO(3) waveguides fabricated by proton exchange in concentrated and diluted pyrophosphoric acid with annealing

Annealed proton-exchanged z-cut LiTaO(3) planar waveguides fabricated with pyrophosphoric acid have been characterized. For proton exchange, the extraordinary index increase Δ n(e) ranged from 0.0119 to 0.0141, depending on the exchange temperature. The effective diffusion coefficient D(e) ranged from 0.1325 μm(2)/h at 240°C to 0.545 μm(2)/h at 280 °C. Single-mode propagation losses were α = 0.7 dB/cm. Compared with benzoic acid, pyrophosphoric acid produces waveguides with a higher Δ n(e) and a lower propagation loss. For proton exchange in lithium phosphate-diluted pyrophosphoric acid, a lower Δ n(e) was obtained, but D(e) and propagation losses were not reduced. After proton exchange, the waveguides were annealed. The surface index initially increased, peaked, and then decreased. The waveguide depth d and the surface index n(s) were measured at regular intervals. Figures and empirical formulas relating the waveguide depth d and the surface index increase Δ n(s) to the anneal time, anneal temperatures, and the waveguide depth after proton exchange are given. An example is given in which, the desired waveguide parameters d and Δ n(s), the fabrication conditions could be calculated with the previously derived formulas. Propagation losses decreased to 0.4 dB/cm after prolonged annealing.

Rerouting of the biceps brachii for paralytic supination contracture of the forearm in tetraplegia due to trauma

Six tetraplegic patients (eight forearms) who had a supination contracture were evaluated after lengthening and rerouting of the biceps brachii. Preoperatively, the mean range of supination and pronation of the forearm was 85 and 14 degrees, respectively. Pronation increased a mean of 75 degrees without affecting the strength of flexion or the flexion-extension arc of motion of the elbow. The forearms that had a satisfactory result had a mean active range of supination of 69 degrees, while those that had a poor result had no active supination. The mean duration of follow-up was twenty-seven months (range, twelve to seventy-two months). The result was considered satisfactory for six limbs and unsatisfactory for two. Functional gains were made in the patients' ability to feed and groom themselves, in their ability to tend to personal hygiene, and in writing and typing skills when the dominant extremity was treated. The results were less predictable for the non-dominant extremity. The maximum gain in the range of motion occurred at three months and the maximum functional gain, by six months.

[ELISA for detection of SC5b-9 levels in plasma and its clinical significance in SLE disease]

Using IgG from rabbit antiserum to human MAC neoantigens and SC5b-9, we established a sandwich ELISA for detecting SC5b-9 levels in human plasma. SC5b-9 was measured in 51 normal plasma samples and 40 plasma samples from patients with SLE. We found that SC5b-9 levels in 96.1% of the controls and in 78.9% of the patients with inactive SLE were below 450 ng/ml, while SC5b-9 levels in 81.0% of the patients with active SLE were above 450 ng/ml. This shows that SC5b-9 levels may be useful for diagnosing patients with clinically active SLE.

[Activation of human serum complement with inulin and purification of SC5b-9]

During a study of the effect of inulin on human complement, we found that complements were partially activated after incubation with inulin for one hour and completely activated after incubation for three hours at 37 degrees C. SC5b-9 was purified by DEAE-Sephacel chromatography, linear sucrose density gradients centrifugation and anti-IgM-protein A affinity chromatography. Purified SC5b-9, as assayed by immunoelectrophoresis, was a single fraction and had C5b, C6, C7/C8 alpha gamma, C8 beta, C9, C92, and S-protein bands appearing in the 10% SDS-PAGE.

Identification of occupational cancer risks using a population-based cancer registry

The study of Xuan Wei fuel use and lung cancer mortality and also the interim case-control study suggested an association between domestic smoky coal use and Xuan Wei lung cancer. The collaborative studies of physical characterization, chemical analysis, and toxicology further substantiated this linkage. The Xuan Wei residents who used smoky coal inhaled extremely high concentrations of mostly submicron-sized particles, which can be inhaled and deposited effectively deep in the lung. These fine particles were composed mostly of organic compounds (72%), including mutagenic and carcinogenic organic compounds, especially in the aromatic and polar fractions. These residents were exposed to polycyclic aromatic compounds, such as benzo[a]pyrene, at comparable or higher levels than those measured in coke oven plants and other occupational environments (International Agency for Research on Cancer 1984). In comparison with wood and smokeless coal combustion emissions, the organic extracts of smoky coal emission particles showed much higher activity of genotoxicity and carcinogenicity. These results all point to a strong etiological link between the complex organic mixtures from smoky coal emissions and Xuan Wei lung cancer. This study and studies reported by other investigators (de Koning et al. 1984) suggested little association between indoor open-fire wood smoke and lung cancer. The less efficient lung deposition of the larger particles from wood combustion, as well as the lower concentrations of biologically active organic compounds, may contribute to the low rate of lung cancer in the wood-burning communes. As to the smokeless coal emissions, the lower particulate concentration and the lower organic content of the particles emitted may also contribute to the low lung cancer rate in the commune using this fuel. In conclusion, the complex organic mixtures from combustion emissions are genotoxic and carcinogenic in animal and in vitro assays. The magnitude of the cancer risks from the complex organic mixtures in man depends on the degree of the exposure, the types of the compounds contained in the mixtures, and the concentrations of these biologically active compounds present in the combustion emissions.

Analysis of pinch and grip strength after carpal tunnel release

This study evaluates the time required for grip and pinch strength to return to preoperative levels after carpal tunnel release. Grip strength was 28% of preoperative level at 3 weeks; 73% by 6 weeks, and returned to the preoperative level by 3 months. At 6 months grip strength was found to increase to 116%. Pinch strength returned sooner being 74% of preoperative level at 3 weeks and 96% by 6 weeks. By 3 months an increase to 108% was seen and at 6 months an increase to 126% of preoperative levels was found. This data should prove useful in predicting when patients may be able to return to their previous level of occupational-related activity.

Representation of T cell functions in liver bearing hepatocellular carcinoma

Thymus-derived cells (T cells) were stained by the immunofluorescent technique, and found to be predominate around the cancer cell nests, in the interstitium, and in the lumen of the sinusoid of the liver bearing hepatocellular carcinoma (hepatoma). The marked T cell predominance in the liver obtained at autopsy in 19 of 13 patients with hepatoma indicates that specific T cell-mediated immunity may be maintained even in the terminal stage of cancer in these patients.

Lack of effect of cecectomy on oxygen consumption and colonic temperature of germfree rats

Oxygen consumption and colonic temperature of germfree rats are lower than those of conventional and conventionalized rats. Cecectomy of weanling germfree rats prevents the development of the very large ceca characteristic of ordinary germfree rats but did not increase oxygen consumption or change colonic temperature.

Influence of vitamin A on wound healing in rats with femoral fracture

Groups of healthy wounded rats with and without comminuted femoral fractures, and maintained on nutritionally complete commercial rat chow with and without supplemental vitamin A, were studied. The test wounds were standard dorsal skin incisions and s.c. polyvinyl alcohol sponge implants. In some experiments the rats were pair-fed; the rats with femoral fracture not receiving supplemental vitamin A were the lead group for determining food allowanced. In other experiments, the rats were allowed food ad libitum. We found that wound healing of rats with femoral fracture was increased when supplemental vitamin A was given, but the supplemental vitamin A did not completely obviate the adverse effects of fracture. The ratio of the breaking strengths of the skin incisions after formalin fixation to the breaking strengths of the incisions in the fresh state was higher in the unsupplemented rats, supporting the results of our earlier experiments that vitamin A increases the rate of collagen cross-linking.

Chemical debridement of burns

The development of effective, non-toxic (local and systemic) methods for the rapid chemical (enzymatic and non-enzymatic) debridement of third degree burns would dramatically reduce the morbidity and mortality of severely burned patients. Sepsis is still the major cause of death of patients with extensive deep burns. The removal of the devitalized tissue, without damage to unburned skin or skin only partially injured by burning, and in ways which would permit immediate (or very prompt) skin grafting, would lessen substantially the problems of sepsis, speed convalescence and the return of these individuals to society as effective human beings, and would decrease deaths. The usefulness and limitations of surgical excision for patients with extensive third degree burns are discussed. Chemical debridement lends itself to complementary use with surgical excision and has the potential advantage over surgical excision in not requiring anesthesia or a formal surgical operation. The authors' work with the chemical debridement of burns, in particular the use of Bromelain, indicates that this approach will likely achieve clinical usefulness. The experimental studies indicate that rapid controlled debridement, with minimal local and systemic toxicity, is possible, and that effective chemotherapeutic agents may be combined with the Bromelain without either interfering with the actions of the other. The authors believe that rapid (hours) debridement accomplished by the combined use of chemical debriding and chemotherapeutic agents will obviate the possibility of any increase in infection, caused by the use of chemical agents for debridement, as reported for Paraenzyme(21) and Travase.(39,48) It is possible that the short term use of systemic antibiotics begun just before and continued during, and for a short time after, the rapid chemical debridement may prove useful for the prevention of infection, as appears to be the case for abdominal operations of the clean-contaminated and contaminated types.

Hemolytic anemia and pancreatic acinar atrophy and fibrosis conditioned by "elemental" liquid diets and the ordinary intestinal microflora

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