Computational mechanobiology model evaluating healing of postoperative cavities following breast-conserving surgery

Breast cancer is the most commonly diagnosed cancer type worldwide. Given high survivorship, increased focus has been placed on long-term treatment outcomes and patient quality of life. While breast-conserving surgery (BCS) is the preferred treatment strategy for early-stage breast cancer, anticipated healing and breast deformation (cosmetic) outcomes weigh heavily on surgeon and patient selection between BCS and more aggressive mastectomy procedures. Unfortunately, surgical outcomes following BCS are difficult to predict, owing to the complexity of the tissue repair process and significant patient-to-patient variability. To overcome this challenge, we developed a predictive computational mechanobiological model that simulates breast healing and deformation following BCS. The coupled biochemical-biomechanical model incorporates multi-scale cell and tissue mechanics, including collagen deposition and remodeling, collagen-dependent cell migration and contractility, and tissue plastic deformation. Available human clinical data evaluating cavity contraction and histopathological data from an experimental porcine lumpectomy study were used for model calibration. The computational model was successfully fit to data by optimizing biochemical and mechanobiological parameters through Gaussian process surrogates. The calibrated model was then applied to define key mechanobiological parameters and relationships influencing healing and breast deformation outcomes. Variability in patient characteristics including cavity-to-breast volume percentage and breast composition were further evaluated to determine effects on cavity contraction and breast cosmetic outcomes, with simulation outcomes aligning well with previously reported human studies. The proposed model has the potential to assist surgeons and their patients in developing and discussing individualized treatment plans that lead to more satisfying post-surgical outcomes and improved quality of life.

Computational Mechanobiology Model Evaluating Healing of Postoperative Cavities Following Breast-Conserving Surgery

Breast cancer is the most commonly diagnosed cancer type worldwide. Given high survivorship, increased focus has been placed on long-term treatment outcomes and patient quality of life. While breast-conserving surgery (BCS) is the preferred treatment strategy for early-stage breast cancer, anticipated healing and breast deformation (cosmetic) outcomes weigh heavily on surgeon and patient selection between BCS and more aggressive mastectomy procedures. Unfortunately, surgical outcomes following BCS are difficult to predict, owing to the complexity of the tissue repair process and significant patient-to-patient variability. To overcome this challenge, we developed a predictive computational mechanobiological model that simulates breast healing and deformation following BCS. The coupled biochemical-biomechanical model incorporates multi-scale cell and tissue mechanics, including collagen deposition and remodeling, collagen-dependent cell migration and contractility, and tissue plastic deformation. Available human clinical data evaluating cavity contraction and histopathological data from an experimental porcine lumpectomy study were used for model calibration. The computational model was successfully fit to data by optimizing biochemical and mechanobiological parameters through the Gaussian Process. The calibrated model was then applied to define key mechanobiological parameters and relationships influencing healing and breast deformation outcomes. Variability in patient characteristics including cavity-to-breast volume percentage and breast composition were further evaluated to determine effects on cavity contraction and breast cosmetic outcomes, with simulation outcomes aligning well with previously reported human studies. The proposed model has the potential to assist surgeons and their patients in developing and discussing individualized treatment plans that lead to more satisfying post-surgical outcomes and improved quality of life.

Hepatitis cRNA quasispecies complexity in patients with alcoholic liver disease

Alcohol abuse is described as a major cofactor in the development of hepatitis C (HCV) associated liver disease and may play a role in the outcome of interferon-based treatment interventions. The association between HCV viral heterogeneity and alcohol has not been previously described. This study was designed to evaluate the quasispecies nature of the HCV population in patients with compensated and decompensated alcoholic liver disease, to test the hypothesis that alcoholics have greater complexity than matched nonalcoholic controls. A nonisotopic heteroduplex complexity assay (HCA) was first validated by comparison with results of quasispecies complexity determined by subcloning and sequencing of amplicon products from the E2/NS1 hypervariable coding region (HVR). Subsequently, this methodology was applied to comparison of 20 compensated (Child's-Pugh A) and decompensated (Child's-Pugh B/C) alcoholic and 20 nonalcoholic controls. The complexity of the HVR, as well as the 5' Untranslated (5'UT) and the NS5b coding domains were evaluated. The HCA methodology provided a reasonable semiquantitative measure of HCV RNA quasispecies variability compared with subclone sequence homology comparison. Overall, alcoholic patients had greater quasispecies complexity (2.65 bands) than nonalcoholic controls (1.6 bands; P =.01). Subset analysis revealed that compensated alcoholic patients had a mean of 3.1 homo/heteroduplex bands per sample whereas Child's-Pugh B/C alcoholics showed intermediate complexity. A similar quasispecies complexity difference was seen in the 5'UTR, but not in the NS5b coding domain. Quasispecies complexity was not associated with viral titer, complementary DNA concentration, or genotype. The differences in quasispecies complexity may help explain reports of poor interferon responsiveness in alcoholic patients.

Hepatitis C serotypes in nonalcoholic and alcoholic patients

Genotyping of the hepatitis C virus (HCV) RNA can be performed by a variety of methods following polymerase chain reaction amplification of a stable RNA portion of the genome. The gold standard is amplification of the RNA from the NS5 region, followed by direct sequencing and homology comparison. This method is extremely labor intensive. In this study, we compared an immunoblot serotyping technique (HCV SIA) to a reverse-hybridization line-probe assay (LiPA) for genotype classification among non-alcoholic HCV infected patients. We then compared and contrasted the response in this cohort to a population of alcoholic patients with HCV infection. To validate the serotype assay, sera from 110 patients with chronic HCV infection was utilized. Serotyping (Chiron SIA) and genotyping by the LiPA (Line Probe Assay, Innogenetics) reverse-hybridization technique was performed. Additionally, both methods were compared to sequence-derived genotyping in 26 patients based on PCR amplification of the NS5 region. After the validation phase, sera from 105 alcoholic patients was genotypically classified by the serologic method. The nonalcoholic and alcoholic groups were then compared with regard to serotype, demographics, and frequency of untypable test results. Among typable pairs, the overall concordance rate between serotyping and LiPA-based genotyping was 93.75%. Patients with genotype 1 by reverse hybridization demonstrated a 95.8% concordance with serotype. Untypable samples were present for both techniques, but since they occurred in different patients, the techniques were complementary. Alcoholic patients were significantly more likely to be infected with untypable serotypes than those without a pattern of alcohol abuse. These patients were also more likely to be HCV RNA negative than sera from typable patients. Serotype 1 was associated with high HCV RNA titer and poor interferon treatment response among both nonalcoholic and alcoholic patients. An immunoblot method for the evaluation of genotype classification was rapid and easily performed compared to sequence-based genotyping. There was a high degree of concordance compared to reverse-hybridization and sequence-based genotype characterization methods. Failure to detect HCV RNA in the serum is associated with a higher likelihood of classification failure. This problem was particularly prevalent in the alcoholic population. HCV RNA titers and treatment outcomes were strongly associated with serotype classification results, demonstrating clinical utility of this assay technique.

Effects of electromagnetic fields and gender on neurotransmitters and amino acids in rats

Epidemiological studies have linked electromagnetic field (EMF) exposure to certain forms of cancer, however only limited laboratory evidence supports a connection between EMF and biological effects. In the present study we exposed male and female rats to low level, 1000 milli-Gauss (mGs), direct current EMF generated with Helmholtz coils for 1 mo or 4 mo. The effects of these EMF exposures on regional brain neurotransmitter metabolism and circulating amino acid concentrations were determined. After 1 mo of EMF exposure the concentration of serotonin was elevated in the hypothalamus of male rats. Levels of the dopamine metabolite, 3-methoxytyramine, were increased in the corpus striatum of male and female rats that were exposed to EMF for 1 mo. Hypothalamic concentration of norepinephrine was elevated in both groups of male rats, as compared to respective female groups, but was not affected by EMF. Similarly, levels of tyrosine were increased in hypothalamus, corpus striatum and nucleus accumbens of male rats, but were not affected by EMF exposure. Following 4 mo of EMF exposure, no significant effect of EMF was observed. Significant sex differences in plasma amino acid concentrations were observed in both studies, with female rats exhibiting decreases in a majority of the amino acids measured. These results are suggestive that short-term exposure may cause small alterations in neurotransmitter metabolism and in circulating amino acids, which dissipate when exposure duration is increased.

Relationship of protein calorie malnutrition to alcoholic liver disease: a reexamination of data from two Veterans Administration Cooperative Studies

The relationship of protein calorie malnutrition (PCM) to alcoholic liver disease was studied in 666 patients enrolled in two Veterans Administration Cooperative Studies. Some findings of malnutrition could be detected early in 62% of the comparison patients (43 subjects who were alcoholic, but had not yet developed clinical or laboratory evidence of liver injury). In those who had progressed to the stage of liver injury sufficient to manifest clinical jaundice (536 patients), some findings of malnutrition were present in every patient (100%). The degree of malnutrition correlated closely with the development of all the serious complications of the liver disease (ascites, encephalopathy, and hepatorenal syndrome), as well as the overall mortality. The degree of malnutrition was also important in predicting response to some forms of treatment. When prednisolone, a catabolic adrenal steroid, was used, efficacy was independent of the level of malnutrition. However, a relationship was observed with the severity of the liver injury [quantified by the level of jaundice and coagulopathy, i.e., Maddrey's discriminant function (DF(Maddrey)]. For prednisolone, the response was seen only when the DF was 81-100 reducing mortality 45% When oxandrolone, an androgenic anabolic steroid treatment was given, efficacy was observed only in those with moderate malnutrition (PCM score 60-79% of normal) and maximized with adequate caloric intake reducing mortality 86%. To simplify the method of calculating the PCM score for predicting response to anabolic therapy, a multiple logistic regression model was developed from the parameters used to assess nutritional status: DF(PCM) = 0.098 (peripheral blood lymphocytes) + 0.078 (creatinine height index).(ABSTRACT TRUNCATED AT 250 WORDS)

Polymorphism at the P450IIE1 locus is not associated with alcoholic liver disease in Caucasian men

Because alcoholic hepatitis and cirrhosis, well-known complications of alcohol abuse, do not occur in all alcoholics, genetic factors such as differences in alcohol-metabolizing enzymes may play a role in the development of alcoholic liver disease. Cytochrome P450IIE1 catalyzes the oxidation of ethanol, producing acetaldehyde and free radicals capable of reacting with and peroxidizing cell membranes. Polymorphisms have been identified in the 5'-flanking region of the P450IIE1 gene that may alter the transcriptional activity of the gene. In this study, we analyzed the P450IIE1 genotypes at the polymorphic PstI and RsaI restriction enzyme sites in 53 Caucasians with severe alcoholic liver disease to determine if there is an association between these polymorphisms and alcoholic liver disease. Subjects that tested positive for the hepatitis C virus were eliminated from the study. To identify the type A (homozygous for the c1 gene), type B (heterozygous for the c1 and c2 genes), and type C (homozygous for the c2 gene) genotypes at the P450IIE1 locus, DNA encompassing the polymorphisms was amplified by polymerase chain reaction, slot-blotted, and probed with allele-specific oligonucleotides. Allele frequencies for the c1 allele were 0.95 for alcoholics with severe liver disease, 0.95 for alcoholics without liver disease, and 0.98 for the general population. No differences in allele frequencies between alcoholic patients with severe liver disease and alcoholics without liver disease were observed.

Prognostic significance of cholestatic alcoholic hepatitis. VA Cooperative Study Group #119

Tissue cholestasis is a histologic feature in some patients with alcoholic liver disease, but its significance is unknown. We studied prospectively the clinical, laboratory, and histologic findings of 306 chronic male alcoholics in whom liver tissue was available. Tissue cholestasis permitted identification of two groups: group I, absent or mild cholestasis (239 patients), and group II, moderate to severe cholestasis (67 patients). Statistical evaluation was performed by Student's t test and regression analyses. In patients with tissue cholestasis, 97% had elevated serum cholylglycine levels, while only 61% had significant jaundice (serum bilirubin greater than 5 mg/dl). In patients without tissue cholestasis, 66% had elevated serum cholylglycine and 13.5% jaundice. Highly significant statistical correlations (P less than 0.0001) were found between cholestasis and malnutrition, prothrombin time, AST, alkaline phosphatase, bilirubin, Maddrey's discriminant function, serum cholylglycine level, albumin, and histologic severity score. In group I, 54% survived 60 months versus 22% in group II (P less than 0.0001). Highly significant statistical correlations (P less than 0.0001) were noted between serum cholylglycine levels and the parameters enumerated earlier, but not with survival. We conclude that tissue cholestasis is a highly significant prognostic indicator of outcome in alcoholic hepatitis and is more consistently associated with bile salt retention than jaundice.

Hepatitis B vaccination. Response of alcoholic with and without liver injury

Alcoholics are at risk to develop hepatitis B infections, chronic active hepatitis, and even hepatoma. Hence, immunization with hepatitis B vaccine is recommended. However, immune abnormalities may coexist which alter their responsiveness to vaccination. This study compares the immune response to this vaccine in controls (group I), alcoholics without overt liver disease (group II), and alcoholics with clinical liver disease (group III). By the seventh month after the initial vaccination, 89% in group I, 70% in group II, and 18% in group III had a response greater than 36 RIA units. The magnitude of the response was significantly different in groups I, II, and III (19,456 vs 8,326 vs 153 RIA units, respectively; P less than 0.05, group I vs III). In those who did not respond, a significant (P less than 0.02) lower helper/inducer (T4) class of lymphocytes was observed as compared to patients who exhibited an adequate response. These observations suggest: (1) that the response to hepatitis B vaccine is a T-cell-dependent event and (2) that in this population, using the existing vaccine, postvaccination evaluations of antibody concentrations are needed before protection against hepatitis B infection can be assumed.

VA Cooperative Study on Alcoholic Hepatitis. IV. The significance of clinically mild alcoholic hepatitis--describing the population with minimal hyperbilirubinemia

As part of a large multicenter Veterans Administration Cooperative Study of Alcoholic Hepatitis, 89 patients with clinically mild biopsy-proven disease were followed for at least 30 months. Although clinical and laboratory abnormalities were minimal, cirrhosis was present in 38%, and mortality was 22% at 30 months. Clinical features suggesting more advanced disease (i.e., ascites and encephalopathy) and laboratory parameters for the diagnosis of alcoholic hepatitis and/or cirrhosis were imprecise and frequently misleading. The histologic diagnosis of cirrhosis correlated best with changes in immunoglobulin A, prothrombin time, and SGOT/SGPT. However, by using logistic discriminant analysis on 26 commonly available laboratory tests to diagnose cirrhosis, only a 72% sensitivity and 88% specificity could be obtained. Mortality in the patients with cirrhosis (10/34) was significantly higher at 1 and 2 yr compared with patients without cirrhosis (10/55, p less than 0.01). The high mortality in noncirrhotics may have resulted from progression to cirrhosis subsequent to the initial evaluation. Thus, liver biopsy in this population with minimal disease seems necessary to establish both an accurate diagnosis and the reversibility of the disease.

VA Cooperative Study on Alcoholic Hepatitis. III: Changes in protein-calorie malnutrition associated with 30 days of hospitalization with and without enteral nutritional therapy

Patients with moderate to severe alcoholic hepatitis and features of protein-calorie malnutrition were studied with respect to changes in their nutritional status during 30 days of hospitalization. Thirty-four patients served as controls, were given a 2500 kcal hospital diet and allowed to eat ad libitum. Twenty-three patients were given, in addition to the hospital diet, a nutrition supplement high in calories, protein, and branched-chain amino acids (Hepatic Aid). Because of anorexia, the controls consumed lesser amounts of both calories and protein while those given the nutritional therapy exceeded their estimated energy requirements (116.1%) and consumed a mean of 98.3 g of protein per day. This was well tolerated despite the fact that portal systemic encephalopathy was present in 72% of the patients. Mortality associated with the liver disease was comparable in both groups, 16.7% in the treated vs 20.6% in the controls. In those patients that survived the 30 days of hospitalization, clinical and biochemical tests of liver injury improved in both groups. With respect to their nutritional status, those given nutritional therapy showed significant improvement in six of the nine parameters (67%) used to assess nutrition. In the controls significant improvement was observed in only two nutritional parameters (22%) while three parameters (33%) deteriorated further. These three were all associated with calorie deprivation (marasmus). This study suggests that patients with acute alcoholic hepatitis require additional nutritional therapy to maintain and improve their nutrition parameters, especially those related to marasmus; and that Hepatic Aid is well tolerated for this purpose.