Sex-related differences in the thanatomicrobiome in postmortem heart samples using bacterial gene regions V1-2 and V4.

Recent studies have revealed distinct thanatomicrobiome (microbiome of death) signatures in human body sites after death. Thanatomicrobiome studies suggest that microbial succession after death may have the potential to reveal important postmortem biomarkers for the identification of time of death. We surveyed the postmortem microbiomes of cardiac tissues from 10 corpses with varying times of death (6-58 h) using amplicon-based sequencing of the 16S rRNA gene' V1-2 and V4 hypervariable regions. The results demonstrated that amplicons had statistically significant (P < 0·05) sex-dependent changes. Clostridium sp., Pseudomonas sp., Pantoea sp. and Streptococcus sp. had the highest enrichment for both V1-2 and V4 regions. Interestingly, the results also show that V4 amplicons had higher abundance of Clostridium sp. and Pseudomonas sp. in female hearts compared to males. In addition, Streptococcus sp. was solely found in male heart samples. The distinction between sexes was further supported by principle coordinate analysis, which revealed microbes in female hearts formed a distinctive cluster separate from male cadavers for both hypervariable regions. This study provides data that demonstrates that two hypervariable regions show discriminatory power for sex differences in postmortem heart samples. SIGNIFICANCE AND IMPACT OF THE STUDY: The findings represent preliminary data of the first thanatomicrobiome investigation of a comparison between 16S rRNA gene V1-2 and V4 amplicon signatures in corpse heart tissues. The results demonstrated that V4 hypervariable region amplicons had statistically significant (P < 0·05) sex-dependent microbial diversity. For example, Streptococcus sp. was solely found in male postmortem heart tissues. Interestingly, the results also show that V4 amplicons had higher abundance of Clostridium sp. and Pseudomonas sp. in female heart tissues compared to males. The finding of Clostridium sp. supports the postmortem clostridium effect in corpse heart tissues.

Microbiota is a primary cause of pathogenesis of chronic wounds.

OBJECTIVE: Diverse microorganisms present on the surface of chronic wounds have been established to constitute wound microbiota. The aims of this study were to quantify the viability of wound microbiota, classify dispersal of viable microbes from the wound, and determine if human wound microbiota can produce a chronic wound in an animal model. METHOD: Wound microbiotas as units (multiple microbial species acting as one infectious agent) were obtained from well-defined human chronic wounds and seeded onto mouse surgical excision wounds to produce chronically infected wounds that closely resembled the chronic wounds observed in the original hosts. RESULTS: We found the wound microbiota harvested from 35 out of 43 (81%) patients could produce similar chronic wounds (producing slough and exudate) in a murine chronic wound model. The top 30 species present in patient wounds were identified in the mouse wounds by molecular sequencing. Koch's postulates could therefore be applied to establish wound microbiota as the cause of the original human chronic wound infections. Evidence-based medicine criteria such as Hill's criteria for causation can all be satisfied by what is currently known about wound microbiota. CONCLUSION: This study demonstrates that wound microbiota actively disseminates from the chronic wound by forces and mechanisms intrinsic to the wound. Koch's postulates and Hill's criteria for causation together suggest chronic wound microbiota to be the main cause underlying the pathogenesis of chronic wounds. DECLARATION OF INTEREST: RW has an equity interest in PathoGenius Labs. No funding was received for this study.

Exposure to cold and acute upper respiratory tract infection.

The incidence of acute upper respiratory tract viral infections (URTI) is directly correlated to air temperature with most URTI occurring seasonally in cold weather. This review looks at four types of cold exposure and examines the evidence and possible mechanisms for any relationship to URTI. The effects of cold are discussed as: 1) Chilling of the nose and upper respiratory tract by breathing cold air, 2) Chilling of the mouth and upper digestive tract by ingestion of cold drinks and food, 3) Acute chilling of the body surface, and, 4) Chilling of the body as a whole with a fall in body temperature, hypothermia. Some studies were found to support a relationship between breathing cold air and chilling the body surface with the development of URTI, although this area is controversial. No evidence was found in the literature to support any relationship between ingestion of cold drinks and food and URTI, and similarly no evidence was found to link hypothermia and URTI.

Cold pleasure. Why we like ice drinks, ice-lollies and ice cream.

This review discusses how the ingestion of cold foods and drinks may be perceived as pleasant because of the effects of cooling of the mouth. The case is made that man has originated from a tropical environment and that cold stimuli applied to the external skin may initiate thermal discomfort and reflexes such as shivering and vasoconstriction that defend body temperature, whereas cold stimuli applied to the mouth are perceived as pleasant because of pleasure associated with satiation of thirst and a refreshing effect. Cold water is preferred to warm water as a thirst quencher and cold products such as ice cream may also be perceived as pleasant because oral cooling satiates thirst. The case is made that cold stimuli may be perceived differently in the skin and oral mucosa, leading to different effects on temperature regulation, and perception of pleasure or displeasure, depending on the body temperature and the temperature of the external environment.

Disruption of a new forkhead/winged-helix protein, scurfin, results in the fatal lymphoproliferative disorder of the scurfy mouse.

Scurfy (sf) is an X-linked recessive mouse mutant resulting in lethality in hemizygous males 16-25 days after birth, and is characterized by overproliferation of CD4+CD8- T lymphocytes, extensive multiorgan infiltration and elevation of numerous cytokines. Similar to animals that lack expression of either Ctla-4 or Tgf-beta, the pathology observed in sf mice seems to result from an inability to properly regulate CD4+CD8- T-cell activity. Here we identify the gene defective in sf mice by combining high-resolution genetic and physical mapping with large-scale sequence analysis. The protein encoded by this gene (designated Foxp3) is a new member of the forkhead/winged-helix family of transcriptional regulators and is highly conserved in humans. In sf mice, a frameshift mutation results in a product lacking the forkhead domain. Genetic complementation demonstrates that the protein product of Foxp3, scurfin, is essential for normal immune homeostasis.

Non-invasive pulsed cavitational ultrasound for fetal tissue ablation: feasibility study in a fetal sheep model.

OBJECTIVES: Currently available fetal intervention techniques rely on invasive procedures that carry inherent risks. A non-invasive technique for fetal intervention could potentially reduce the risk of fetal and obstetric complications. Pulsed cavitational ultrasound therapy (histotripsy) is an ablation technique that mechanically fractionates tissue at the focal region using extracorporeal ultrasound. In this study, we investigated the feasibility of using histotripsy as a non-invasive approach to fetal intervention in a sheep model. METHODS: The experiments involved 11 gravid sheep at 102-129 days of gestation. Fetal kidney, liver, lung and heart were exposed to ultrasound pulses (< 10 µs) delivered by an external 1-MHz focused ultrasound transducer at a 0.2-1-kHz pulse-repetition rate and 10-16 MPa peak negative pressure. Procedures were monitored and guided by real-time ultrasound imaging. Treated organs were examined by gross and histological inspection for location and degree of tissue injury. RESULTS: Hyperechoic, cavitating bubble clouds were successfully generated in 19/31 (61%) treatment attempts in 27 fetal organs beneath up to 8 cm of overlying tissue and fetal bones. Histological assessment confirmed lesion locations and sizes corresponding to regions where cavitation was monitored, with no lesions found when cavitation was absent. Inability to generate cavitation was primarily associated with increased depth to target and obstructing structures such as fetal limbs. CONCLUSION: Extracorporeal histotripsy therapy successfully created targeted lesions in fetal sheep organs without significant damage to overlying structures. With further improvements, histotripsy may evolve into a viable technique for non-invasive fetal intervention procedures.

Human cell hybrids: analysis of transformation and tumorigenicity.

Intraspecific human-human cell hybrids provide a stable model system with which to investigate the genetic control of transformed and tumorigenic phenotypes. Using this system it has been shown that these phenotypes are under separate genetic control. Furthermore, the tumorigenic phenotype can be complemented by fusion of different tumorigenic cells, resulting in nontumorigenic hybrids. This system also provides information on the control of differentiated function. Molecular cytogenetic techniques should reveal the nature of the chromosomal control of neoplastic transformation.

Candidate gene associated with a mutation causing recessive polycystic kidney disease in mice.

A line of transgenic mice was generated that contains an insertional mutation causing a phenotype similar to human autosomal recessive polycystic kidney disease. Homozygotes displayed a complex phenotype that included bilateral polycystic kidneys and an unusual liver lesion. The mutant locus was cloned and characterized through use of the transgene as a molecular marker. Additionally, a candidate polycystic kidney disease (PKD) gene was identified whose structure and expression are directly associated with the mutant locus. A complementary DNA derived from this gene predicted a peptide containing a motif that was originally identified in several genes involved in cell cycle control.

Renal ablation by histotripsy--does it spare the collecting system?

PURPOSE: The feasibility of histotripsy (transcutaneous nonthermal mechanical tissue fractionation) was previously demonstrated in an in vivo rabbit renal cortex model. We explored the spectrum of histotripsy bio-effects on different tissue types in an in vitro porcine kidney model. MATERIALS AND METHODS: Using an 18 element focused annular array ultrasound system we performed histotripsy treatments in 5 in vitro porcine kidneys, targeting 7 cortical volumes and 17 tissue volumes bridging the cortex, medulla and/or collecting system. Treated areas were observed using ultrasound. In 5 lesions methylene blue was infused into the collecting system to evaluate the preservation of collecting system integrity. Kidneys were sectioned and examined grossly for evidence of tissue fractionation, ie the presence of histotripsy paste, or fixed in formalin and prepared for histological analysis. RESULTS: Histotripsy of renal cortical tissue created tissue defects in the cortical area treated. Histotripsy targeting the renal collecting system, medulla and renal cortex resulted in tissue fractionation in the area of the cortex, intermediate damage in the medulla and minimal damage to the collecting system. CONCLUSIONS: There is a differential histotripsy treatment effect when comparing renal cortical tissue to renal collecting system. There is no significant architectural disruption of the renal collecting system after histotripsy. This differential effect is a notable finding that may prove useful in future planning of ablative treatments for renal tissue.

Epidermal growth factor receptor activity mediates renal cyst formation in polycystic kidney disease.

A consistent phenotype observed in both human patients and several different mouse models of autosomal recessive polycystic kidney disease (ARPKD) is an increased activity of the epidermal growth factor receptor (EGFR) in the affected kidneys. To determine whether this increased activity of the EGFR is a functional event that is directly part of the disease pathway of renal cyst formation, we used a genetic approach to introduce a mutant EGFR with decreased tyrosine kinase activity into a murine model of ARPKD. We found that the modified form of the EGFR could block the increase in EGFR-specific tyrosine kinase activity that normally accompanies the development of renal cysts, and this correlated with an improvement in kidney function and a substantial decrease in cyst formation in the collecting ducts. These results suggest that changes in the expression of the EGFR contribute to the formation of cysts in the collecting ducts, and that drugs that target the tyrosine kinase activity of the EGFR may potentially be therapeutic in ARPKD.

Chromosomal radiosensitivity during the G2 cell cycle period and cytopathology of human normal x tumor cell hybrids.

The relationship between tumorigenicity and enhanced chromosomal radiosensitivity during the G2 cell cycle phase was examined through the use of nontumorigenic human cell hybrids and their nontumorigenic and tumorigenic segregants. The hybrid cells were produced by fusion of a normal and tumor cell. The parental lines, including HeLa and three fibroblast lines, one of skin and two of fetal lung origin, were also examined. The tumorigenic lines, which had cytological features associated with clinical cancer, showed a significantly higher incidence of chromatid breaks and gaps following X-irradiation during G2 than the normal skin line or the nontumorigenic hybrids. The hybrids and their nontumorigenic subclones had cytological features which are predominantly found with a benign clinical course and had the G2 chromosomal radiosensitivity more characteristic of the normal parental cells. Like tumorigenic cells, fetal cells exhibited enhanced G2 chromosomal radiosensitivity which could be suppressed in fetal X tumor cell hybrids. This observation suggests that the molecular basis for radiosensitivity in fetal cells differs from that of tumor cells. The enhanced G2 chromosomal radiosensitivity of a tumor cell, which appears to result from deficient DNA repair, is suppressed by fusion with a normal cell. Thus, the radiosensitivity, like tumorigenicity, behaves as a recessive trait. Although a Mendelian analysis is not possible with this material, the segregation of enhanced G2 chromosomal radiosensitivity with the neoplastic phenotype suggests that the two may be genetically linked.

The tetratricopeptide repeat containing Tg737 gene is a liver neoplasia tumor suppressor gene.

The Tg737 gene was investigated for gross alterations in a series of rodent/human liver tumors and human tumorigenic cell lines. The Tg737 gene was found to be altered in approximately 40% of the rodent chemically-induced liver tumors, 40% of the human liver tumors, and in liver, kidney and pancreatic human tumor cell lines. Ectopic re-expression of the Tg737 gene in a Tg737 deleted mouse liver tumor cell line resulted in suppression of tumorigenic growth, without altering in vitro cell culture growth. Treatment of mice which are either homozygous normal or heterozygous deleted at the Tg737 locus with the carcinogen diethylnitrosamine resulted in an increase in preneoplastic foci formation in the Tg737 heterozygous deleted mice. Ectopic expression of the Tg737 gene results in multinucleated cells, loss of Tg737 gene expression results in the proliferation of liver stem cells (oval cells) without concomitant differentiation, and reexpression of the Tg737 gene reestablished responsiveness to external differentiation factors. We believe this is the first report demonstrating tumor suppression activity for a tetratricopeptide repeat gene family member and provides insights into the function of this family of genes in mammalian cells.

Phenotypic variations of orpk mutation and chromosomal localization of modifiers influencing kidney phenotype.

The Oak Ridge polycystic kidney (orpk) mutant mouse model resulted from a transgene insertion into the Tg737 gene and exhibits a pleiotropic syndrome with lesions in the kidney, liver, and pancreas. We found marked differences in the phenotypic expression of the orpk mutation when bred on different genetic backgrounds. In the FVB/N background, the phenotype is very severe for kidney, pancreas, and liver lesions. To evaluate better how genetic background might influence the expressivity of the orpk phenotype, we bred the transgene into the C3HeB/FeJLe (C3H) genetic background. We performed a genome-wide scan using backcross and intercross populations with more than 150 markers to map the chromosomal location of the modifier genes that differ in the FVB/N and C3H genetic backgrounds that affect the severity of kidney disease in the orpk mouse. Low-resolution interval mapping was performed using the Map Manager QTb program, with the interval explaining a significant portion of the variance being the distal end of chromosome 4.

Long-term cultivation of canine keratinocytes.

The growth characteristics and morphology of canine keratinocytes grown in vitro were studied. Keratinocytes from canine oral mucosa, ear skin, and ventral abdominal skin were grown in culture either as explants or as dispase/trypsin-derived suspensions in the absence of a feeder cell layer. Cholera toxin and epidermal growth factor were essential to the successful long-term growth and propagation of the cells during multiple passages. Keratinocytes from all tissue sources, either as primary cultures or subcultivated for up to 10 passages, had growth characteristic and morphology similar to that reported in other species. The use of cultured canine keratinocytes should provide a suitable model for comparative in vitro studies of the pathogenesis of dermatologic diseases.

Differential expression of cell surface antigens of canine keratinocytes defined by monoclonal antibodies.

Nine monoclonal antibodies (MAb) directed against cell surface antigens of canine keratinocytes define distinct keratinocyte subpopulations owing to the differential expression of these antigens during the process of differentiation and depending on the tissue location of the cells. There was distinct antigenic heterogeneity between the different layers of stratified squamous epithelium and between stratified squamous epithelial of different tissue origin. Two MAb reacted only with antigens expressed by esophageal mucosa. Three MAb bound to antigens on keratinocytes of the suprabasilar and granular layers of stratified squamous epithelia, and they crossreacted with the transitional epithelial cells of the urinary tract. Two MAb reacted with antigens only expressed on differentiated cells, superficially located in the stratified squamous epithelium. The use of these MAb as markers for keratinocytes in studies on the characterization and differentiation of keratinocytes, as well as in tumor diagnosis and allograft transplantation, is discussed.

A study of forty-nine consecutive Whipple resections for periampullary adenocarcinoma.

BACKGROUND: We designed a program to evaluate the morbidity, mortality, survival rates, and patient's quality of life after Whipple resection for pancreatic and other periampullary adneocarcinoma. PATIENTS AND METHODS: After studying 11 fresh and unembalmed cadavers to learn the regional anatomy and to practice the surgical techniques for traditional Whipple procedure by the senior author (JS), 49 patients aged 56 to 84 years old were treated with Whipple's pancreatoduocenectomy. RESULTS: There was no postoperative mortality or morbidity from anastomotic leakage. All 49 patients were discharged in an improved condition following surgery, including 5 patients with emergency resection. Eight patients are alive at the time of this writing, including 2 patients who had their pancreatic cancer resected 168 and 139 months ago. CONCLUSIONS: In the opinion of these authors, treatment of all resectable cancers with Whipple's pancreatoduodenectomy offers not only a superior palliation but also the hope of cure.

Plasma cell myeloma in the horse. A case report and literature review.

Plasma cell myelomas in horses have been reported infrequently. Data from 10 cases, 9 from the literature and 1 new case, are used to characterize the disease in the horse. Hot-blooded horses (7/10), specifically Quarter Horses (4/10), were most often affected. Median age at diagnosis was 11 years (range, 3 mo-22 yr) and both male (5) and female horses (5) were represented equally. Clinical findings included weight loss (6/8), anorexia (4/8), fever (4/8), limb edema (4/8), pneumonia (3/8), rear leg paresis/ataxia (3/8), epistaxis (3/8), palpable lymphadenopathy (2/8), and bone pain (2/8). Anemia (8/8) was present routinely, and in three horses, RBCs were macrocytic. Leukopenia (2/8), thrombocytopenia (2/8), and circulating plasma cells (3/8) were variable findings. Except for abnormal protein concentrations and hyponatremia (3), abnormal results from serum biochemical analysis including hypocholesterolemia (1), hypercalcemia (1), and azotemia (1) were reported infrequently. Hyperproteinemia (8/9), hypoalbuminemia (7/9), and hyperglobulinemia (8/9) were characteristic but not invariable findings. Monoclonal proteins (7/7) were detected in the alpha 2, beta, or gamma region by serum electrophoresis. The paraprotein's heavy chain, determined in four horses, was a subclass of IgG. Three horses had decreased concentrations of normal immunoglobulins. Variable proteinuria (trace to 4+) was detected by routine urinalysis in four of six horses. Bence Jones proteinuria was detected in one of five horses (heat precipitation) and monoclonal proteins were detected in two of three electrophoresed urine samples. Three of the horses had lytic bone lesions detected radiographically. Bone marrow aspirates were diagnostic in two of five horses.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigen expression in cultured oral keratinocytes from dogs.

Oral keratinocytes from dogs were cultured on either collagen gels or artificial matrices at the air-liquid interface, and the expression of keratinocyte antigens and basement membrane components was determined, using various monoclonal and polyclonal antibodies. Keratinocytes grown on collagen gels expressed pemphigus vulgaris, pemphigus foliaceous, and bullous pemphigoid antigens. Diffuse, suprabasal, and superficial keratinocyte membrane differentiation antigens identified by various monoclonal antibodies also were expressed in a pattern identical to that observed in the native tissue. Laminin and type-IV collagen were deposited at the keratinocyte-collagen interface in a patchy distribution. When synthetic matrices were used, the oral keratinocytes differentiated, but to a lesser extent than cells grown on collagen gels. Antigen expression for cells grown on synthetic matrices was similar to that for cells on collagen, except for failure of the keratinocytes on synthetic membranes to express superficial cell antigens and pemphigus foliaceous antigens.

Ultrastructure of cultured canine oral keratinocytes.

Keratinocytes from explants of the oral mucosa of dogs were grown in culture for five passages. The ultrastructure of primary cultures and fully developed subcultures passaged 1, 3, and 5 times was examined. At every stage, the cells had the morphologic characteristics of epithelial cells and formed a multilayered squamous epithelium. The basal cells had the characteristics of metabolically active cells, whereas the suprabasal cells and the cells at the media interface expressed many, but not all, of the organelles and cell surface characteristics associated with keratinocyte differentiation. Keratohyalin granules were located in the suprabasal and superficial cells. Cell size and shape and the relationship between cells in the layers also reflected the morphologic characteristics of the parent tissue. Cells maintained this typical structure through all passages and the cultures changed minimally for up to a week after development.

Monoclonal antibodies: cell surface markers for canine keratinocytes.

Plasma membranes were isolated from cultured canine keratinocytes by paraformaldehyde-induced membrane vesiculation. The isolated plasma membrane vesicles retained cell surface antigens (eg, a pemphigus vulgaris antigen). These membrane vesicles were used as an antigen source for the production of monoclonal antibodies. Eight antibodies that had specific reactivity to the cytoplasmic membrane of keratinocytes on frozen sections of canine esophagus were identified by use of an indirect immunoperoxidase method. The stratified squamous epithelium of the esophageal mucosa had 4 staining patterns. When applied to frozen sections of canine skin, lip, and tongue, the antibodies had different tissue specificities for differing stratified squamous epithelia. Using sodium dodecyl sulfate polyacrylamide-gel electrophoresis and the western blot technique, one of the antibodies was specific for a 60-kD cell surface molecule. Therefore, such monoclonal antibodies may be useful in defining heterogeneity between different stratified squamous epithelia, in identifying biologically important surface antigens, or in the diagnosis of tumors.