Author Correction: Consistent success in life-supporting porcine cardiac xenotransplantation.

In this Letter, Mayuko Kurome and Valeri Zakhartchenko have been added to the author list (affiliated with Institute of Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Munich, Germany). The author list and 'Author contributions' section have been corrected online; see accompanying Amendment.

Consistent success in life-supporting porcine cardiac xenotransplantation.

Heart transplantation is the only cure for patients with terminal cardiac failure, but the supply of allogeneic donor organs falls far short of the clinical need1-3. Xenotransplantation of genetically modified pig hearts has been discussed as a potential alternative4. Genetically multi-modified pig hearts that lack galactose-α1,3-galactose epitopes (α1,3-galactosyltransferase knockout) and express a human membrane cofactor protein (CD46) and human thrombomodulin have survived for up to 945 days after heterotopic abdominal transplantation in baboons5. This model demonstrated long-term acceptance of discordant xenografts with safe immunosuppression but did not predict their life-supporting function. Despite 25 years of extensive research, the maximum survival of a baboon after heart replacement with a porcine xenograft was only 57 days and this was achieved, to our knowledge, only once6. Here we show that α1,3-galactosyltransferase-knockout pig hearts that express human CD46 and thrombomodulin require non-ischaemic preservation with continuous perfusion and control of post-transplantation growth to ensure long-term orthotopic function of the xenograft in baboons, the most stringent preclinical xenotransplantation model. Consistent life-supporting function of xenografted hearts for up to 195 days is a milestone on the way to clinical cardiac xenotransplantation7.

Cutaneous apocrine gland neoplasia in 16 captive African wild dogs (Lycaon pictus).

This retrospective study documents the occurrence of single and multiple cutaneous apocrine gland tumours (CATs) on the dorsal midline of 16 captive African wild dogs (AWDs, Lycaon pictus) derived from 161 submissions to diagnostic laboratories in South Africa, France and Germany between 1997 and 2022. Animals included in the study came from zoological institutions in South Africa (n = 2), France (n = 5) and Germany (n = 1) and ranged from 5 to 14 years of age. Fifteen affected animals were female (94%) and one was male. CATs presented as raised, hairless, multilobular, grey firm masses, consistently located along the dorsal midline. Apart from a single cutaneous apocrine adenoma and a cystadenoma occurring concurrently with two non-cystic adenocarcinomas, neoplasms were consistent with malignant cutaneous apocrine adenocarcinomas with lymphatic spread and visceral metastases. Advanced age and female sex were identified as risk factors. A genetic component or association with the increasing use of GnRH agonist contraceptives was suspected but could not be established. This study highlights the need for close clinical monitoring of AWDs over the age of 5 years for the development of CATs along the dorsal midline and supports early surgical intervention. More research is needed to determine the role of inbreeding, endocrine changes and husbandry factors that may play a role in the development of CATs on the dorsal midline of AWDs.

Mass Occurrence of Anatoxin-a- and Dihydroanatoxin-a-Producing Tychonema sp. in Mesotrophic Reservoir Mandichosee (River Lech, Germany) as a Cause of Neurotoxicosis in Dogs.

In August 2019, three dogs died after bathing in or drinking from Mandichosee, a mesotrophic reservoir of the River Lech (Germany). The dogs showed symptoms of neurotoxic poisoning and intoxication with cyanotoxins was considered. Surface blooms were not visible at the time of the incidents. Benthic Tychonema sp., a potential anatoxin-a (ATX)-producing cyanobacterium, was detected in mats growing on the banks, as biofilm on macrophytes and later as aggregations floating on the lake surface. The dogs' pathological examinations showed lung and liver lesions. ATX and dihydroanatoxin-a (dhATX) were detected by LC-MS/MS in the stomachs of two dogs and reached concentrations of 563 and 1207 µg/L, respectively. Anatoxins (sum of ATX and dhATX, ATXs) concentrations in field samples from Mandichosee ranged from 0.1 µg/L in the open water to 68,000 µg/L in samples containing a large amount of mat material. Other (neuro)toxic substances were not found. A molecular approach was used to detect toxin genes by PCR and to reveal the cyanobacterial community composition by sequencing. Upstream of Mandichosee, random samples were taken from other Lech reservoirs, uncovering Tychonema and ATXs at several sampling sites. Similar recent findings emphasize the importance of focusing on the investigation of benthic toxic cyanobacteria and applying appropriate monitoring strategies in the future.

Retrobulbar Sinus Injection of Doxorubicin is More Efficient Than Lateral Tail Vein Injection at Inducing Experimental Nephrotic Syndrome in Mice: A Pilot Study.

Doxorubicin-induced nephropathy in mice is a model for studying experimental nephrotic syndrome. It corresponds to puromycin aminonucleoside nephrosis in rats. In this model, susceptible 129 S1/SvImJ mice are administered a rapid intravenous injection that can be accomplished via either the lateral tail vein or the retrobulbar sinus. Because doxorubicin is a highly toxic substance, extravasation must be avoided during the administration of the intravenous injection to prevent the development of large necrotizing lesions and exacerbation of the animals' stress. In the present study, we compared the safety and stress of these two injection routes by using histopathological analyses of the animals' orbital cavities or tails, respectively. The injection of 14.5 µg/g body weight doxorubicin into the mice's lateral tail veins (n = 9) or retrobulbar sinuses (n = 19) caused no clinically detectable stress or impairment. Histopathologies of the specimens five days after doxorubicin injection revealed inflammatory lesions at the injection sites in both groups. In the orbital sinus specimens from the retrobulbar-injected group, fibrosis was evident 25 days after injection. Moreover, while all of the retrobulbar-injected mice (100%) developed nephrotic syndrome, tail vein-injected mice had a significantly lower response rate (66%, p = 0.047, Fisher's exact test) and exhibited only attenuated features of nephrotic syndrome. It was therefore concluded that doxorubicin administration via either lateral tail vein or retrobulbar sinus injections led to a similar induction of histopathological changes with no effects on the clinical well-being of the mice. However, retrobulbar sinus injections were more efficient for inducing experimental nephrotic syndrome.

[Intraocular melanoma in a 10-year-old female llama (Lama glama)]. / Intraokuläres Melanom bei einer 10 Jahre alten Lamastute (Lama glama).

A 10-year-old female llama was presented with a continually growing mass of the left eye. It displayed exophthalmus. The nictitating membrane was hyperemic. The cornea was completely opaque, vascularised, ulcerated and covered with abnormal tissue. Deeper structures of the eye were not visible. The right eye was unaffected. The left eye was removed under general anaesthesia. On histological examination, an amelanotic melanoma was diagnosed. The cornea, sclera, vitreous body and lens could not be differentiated. Fourteen months later, the llama was presented to the clinic because of a mass in the left orbita and right-sided blindness. Because of its poor general condition, the animal was euthanised. Histopathological examination revealed recurrence of the amelanotic melanoma with metastases to the regional lymph nodes and infiltration of the optical nerve, leading to the rightsided blindness.

Occurrence of dysentery-like diarrhoea associated with Brachyspira suanatina infection on a German fattening pig farm.

The anaerobic intestinal spirochaete Brachyspira (B.) suanatina was first described in 2007 but since then no further isolates have been reported from pigs. Accordingly, when the species was validly published in 2016, the overall occurrence and clinical relevance in pigs were unknown. In a fattening farm in southern Germany, mucohaemorrhagic diarrhoea was observed in 60 per cent (750 animals) of the finisher pigs. A diagnostic workup including Brachyspira culture, Salmonella culture, Lawsonia intracellularis-specific, B. hyodysenteriae-specific and B. pilosicoli-specific multiplex PCR and postmortem examination of severely affected pigs was performed. Tests for Salmonella species, Lawsonia intracellularis and B. hyodysenteriae were all negative. Gross and microscopic lesions were in agreement with dysentery and spirochaetes could be demonstrated by silver staining in tissue samples of the caecum at the ileal papilla. B. suanatina was cultured from faeces or colon of all (five) animals sampled and identified using nox-RFLP, partial nox-gene-sequencing and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). According to the initial report from Scandinavia, B. suanatina can be isolated from birds and cross-species infection could be demonstrated infecting pigs with an avian isolate. Thus outdoor production as in the case presented here and international trade may pose a risk for infection of naive herds.

Vaccine safety testing using magnetic resonance imaging in suckling pigs.

Safety testing is one major part of the licensing procedure for veterinary vaccines and demands a large number of animals. Magnetic resonance imaging (MRI) was tested as an alternative, which may lead to a reduction in numbers of animals required for safety testing, and, correspondingly to a detailed description of the three-dimensional extent of the local tissue reaction repetitively in live pigs. In previous pig studies the following questions arose:To answer these questions the following study was performed by comparing two vaccine groups of suckling piglets (8 animals per group; A and B) with two control groups (4 animals per group; C and D). One control group was injected with a saline solution (C) and the other was only tattoo marked (D). The animals were examined using MRI at days 1, 8, 15, 22, 29, 36, and 43 post vaccination, ending with a final pathomorphologic examination. Pathomorphologic examination confirmed MRI findings. Saline solution does not result in a local tissue reaction as detected after injecting vaccines. Tattoo marking causes no local tissue reaction, neither in MRI nor in pathomorphologic examination. Therefore, MRI can be used as an alternative method for safety testing of vaccines in pigs of different age categories offering repetitive measurements of local tissue reactions. Involved cells might be examined only in a final pathomorphologic examination at the end of the trial on a reduced number of animals.

Distribution of Porcine Cytomegalovirus in Infected Donor Pigs and in Baboon Recipients of Pig Heart Transplantation.

The porcine cytomegalovirus (PCMV) is a herpesvirus that may pose a risk for xenotransplantation using pig cells, tissues, or organs. Here, three orthotopic pig heart transplantations into baboons were studied. To detect PCMV, a real-time PCR and a Western blot assay based on four PCMV protein sequences, including two tegument proteins, were used. The transmission of PCMV from the donor pig to the recipient baboon was found in two cases, despite PCMV not being detected in the blood of the donor pigs by real-time PCR. Although it was not in the blood, PCMV was detected in different organs of the donor pigs, and in sibling animals. Immunohistochemistry using an antiserum that is specific for PCMV detected virus protein-expressing cells in all of the organs of the recipient baboon, most likely representing disseminated pig cells. Therefore, for the first time, the distribution of PCMV in organs of the donor pigs and the recipient baboons was described. In addition, baboon cytomegalovirus (BaCMV) was found activated in the recipient, and a screening for hepatitis E virus (HEV) and porcine lymphotropic herpesviruses (PLHV) was performed. For the first time, a cross-reactivity between antibodies directed against PCMV and BaCMV was found.

Hepatic Failure After Pig Heart Transplantation Into a Baboon: No Involvement of Porcine Hepatitis E Virus.

BACKGROUND: After transplantation of pig hearts into baboons, a particularly high increase of liver parameters was observed in 1 animal. To evaluate whether porcine hepatitis E virus (HEV) was involved in the pathological changes, the donor pig and the recipient baboon were screened for the presence of HEV. MATERIAL AND METHODS: Screening for HEV was performed using highly sensitive and specific PCR methods as well as immunological screening for HEV-specific antibodies. RESULTS: HEV was not detected in the donor pig or the baboon recipient. At necropsy, histopathological examination of liver sections showed acute coagulative necrosis of hepatocytes and hemorrhage, but minimal inflammatory cell activity. CONCLUSIONS: The liver failure observed in the recipient animal was not due to transmission of porcine HEV. Liver failure could have been caused by the onset of cardiac failure related to delayed transplant rejection.