Shark tooth regeneration reveals common stem cell characters in both human rested lamina and ameloblastoma

The human dentition is a typical diphyodont mammalian system with tooth replacement of most positions. However, after dental replacement and sequential molar development, the dental lamina undergoes apoptosis and fragments, leaving scattered epithelial units (dental lamina rests; DLRs). DLRs in adult humans are considered inactive epithelia, thought to possess limited capacity for further regeneration. However, we show that these tissues contain a small proportion of proliferating cells (assessed by both Ki67 and PCNA) but also express a number of common dental stem cell markers (Sox2, Bmi1, β-catenin and PH3) similar to that observed in many vertebrates that actively, and continuously regenerate their dentition. We compared these human tissues with the dental lamina of sharks that regenerate their dentition throughout life, providing evidence that human tissues have the capacity for further and undocumented regeneration. We also assessed cases of human ameloblastoma to characterise further the proliferative signature of dental lamina rests. Ameloblastomas are assumed to derive from aberrant lamina rests that undergo changes, which are not well understood, to form a benign tumour. We suggest that dental lamina rests can offer a potential source of important dental stem cells for future dental regenerative therapy. The combined developmental genetic data from the shark dental lamina and ameloblastoma may lead to the development of novel methods to utilise these rested populations of adult lamina stem cells for controlled tooth replacement in humans

Active laser frequency stabilization using neutral praseodymium (Pr)

We present a new possibility for the active frequency stabilization of a laser using transitions in neutral praseodymium. Because of its five outer electrons, this element shows a high density of energy levels leading to an extremely line-rich excitation spectrum with more than 25000 known spectral lines ranging from the UV to the infrared. We demonstrate the active frequency stabilization of a diode laser on several praseodymium lines between 1105 and 1123 nm. The excitation signals were recorded in a hollow cathode lamp and observed via laser-induced fluorescence. These signals are strong enough to lock the diode laser onto most of the lines by using standard laser locking techniques. In this way, the frequency drifts of the unlocked laser of more than 30 MHz/h were eliminated and the laser frequency stabilized to within 1.4(1) MHz for averaging times >0.2 s. Frequency quadrupling the stabilized diode laser can produce frequency-stable UV-light in the range from 276 to 281 nm. In particular, using a strong hyperfine component of the praseodymium excitation line E = 16 502.616_7/2 cm^-1 -> E' = 25 442.742_9/2 cm^-1 at lambda = 1118.5397(4) nm makes it possible - after frequency quadruplication - to produce laser radiation at lambda/4 = 279.6349(1) nm, which can be used to excite the D2 line in Mg^+.Comment: 10 pages, 14 figure

Effects on blood gas and haematological parameters during butorphanoldexmedetomidine- tiletamine-zolazepam anaesthesia in cats

The present study was undertaken to evaluate the effects of butorphanol, dexmedetomidine, tiletamine and zolazepam anaesthesia on blood gas and haematological parameters in cats. These parameters were monitored before anaesthetic induction and 10 minutes following anaesthetic induction. Statistical analysis revealed that no significant changes exist and the parameters were within the normal reference range for cats. Therefore, this anaesthetic technique could be employed safely for elective surgery in cats

Common principles and best practices for engineering microbiomes

Despite broad scientific interest in harnessing the power of Earth's microbiomes, knowledge gaps hinder their efficient use for addressing urgent societal and environmental challenges. We argue hat structuring research and technology developments around a design-build-test-learn (DBTL) cycle will advance microbiome engineering and spur new discoveries on the basic scientific principles governing microbiome function. In this Review, we present key elements of an iterative DBTL cycle for microbiome engineering, focusing on generalizable approaches, including top-down and bottom-up design processes, synthetic and self-assembled construction methods, and emerging tools to analyze microbiome function. These approaches can be used to harness microbiomes for broad applications related to medicine, agriculture, energy, and the environment. We also discuss key challenges and opportunities of each approach and synthesize them into best practice guidelines for engineering microbiomes. We anticipate that adoption of a DBTL framework will rapidly advance microbiome-based biotechnologies aimed at improving human and animal health, agriculture, and enabling the bioeconomy

Supracutaneous locking compression plating for the management of humerus fracture in a dog

A dog was presented to the University Veterinary Hospital, Kokkalai with a history of nonweight bearing lameness on left forelimb and was diagnosed as humerus fracture. Supracutaneous locking compression plating was carried out after open reduction under general anaesthesia. Periodic clinical and radiographic evaluations were conducted at two weeks interval for a period of six weeks until the plate removal. Physiological and haematological parameters were within the normal range. The serum alkaline phosphatase level was high at the time of presentation and decreased progressively. The dog returned to sound gait, normal weight bearing and satisfactory functional limb usage by sixth post operative week. The fracture healed with periosteal and endosteal callus. The implant was intact and patient acceptance was satisfactory throughout the observation period

Effects of intravenous lignocaine on anaesthetic parameters in cattle under dexmedetomidine-butorphanol-ketaminemidazolam- isofluraneanaesthesia

The present study was conducted for clinical evaluation of a multimodal anaesthetic protocol using butorphanol-dexmedetomidine-midazolam-ketamine-isoflurane and lignocaine continuous rate infusion (CRI) in six cross-bred female cattle. Preanaesthetics used were butorphanol and dexmedetomidine which were administered intravenously at dose rates of 0.05 mg/kg and 1 μg/ kg body weight, respectively. Ketamine and midazolam were intravenously administered at dose rates of 4.0 and 0.2 mg/kg body weight respectively, to induce anaesthesia. Isoflurane was used to maintain anaesthesia after endotracheal intubation, at a concentration of 1.05 ± 0.97 per cent concentration in 100 per cent oxygen using a large animal anaesthesia machine. Simultaneously, intravenous lignocaine was administered at a bolus dose of 2 mg/kg body weight followed by a CRI of 3 mg/kg body weight/hour using a volumetric infusion pump. Isoflurane sparing effect of intravenous lignocaine reduced the required concentration of isoflurane for maintenance. The third plane of surgical anaesthesia was maintained and various surgical procedures were done. Recovery was smooth. Other than the mild regurgitation of ruminal fluid in an animal, no anaesthetic complications were noticed

Evaluation of keeping quality of canine platelet rich plasma under different storage conditions

Platelet rich plasma (PRP) therapy is an integral part of regenerative medicine as the platelets possess a good healing capacity owing to the presence of a wide variety of growth factors in the platelet granules found in the cytoplasm of the platelet. Autologous PRP was prepared from the blood of the patient itself, without any preservatives. Storage of PRP was one of the main hurdles of the treatment modality. During storage, the platelet counts may get reduced, undergo activation or get contaminated with bacteria as no preservatives are used in the preparation of autologous PRP. Cytological changes and microbial quality of the PRP during storage at 4oC and -20oC for seven days were analysed in this study. Reduction in platelet count and the chance of microbial contamination were less when autologous PRP was stored at -20°C compared to 4°C

Life cycle cost assessment of insect based feed production in West Africa

While there is a growing body of research investigating the technical feasibility and nutritional properties of insect based feeds (IBFs), thus far little attention has been devoted to gauge the economic implications of implementation. This study has investigated the economic performance of ex-ante modelled IBF production systems operating in the geographical context of West Africa. A Life Cycle Cost (LCC) analysis of recently published life cycle inventory (LCI) data served as a basis to analyse and compare the economic performances of IBF production systems using Musca domestica and Hermetia illucens reared on different substrates. To gauge the application potential of IBF in West Africa, estimated breakeven sale prices of IBFs were benchmarked against the customary market prices of conventional feeds. The results show that the economic performance of IBF production in West Africa is largely determined by the costs attributed to labour and the procurement of rearing substrates, attesting economic advantages to the production of M. domestica larvae by measure of breakeven price (1.28–1.74 EUR/kg IBF) and LCC (1.72–1.99 EUR/kg IBF). A comparison of the breakeven sale prices of IBF with market prices of conventional feeds suggest that IBF has potential to substitute imported fishmeal, but findings offer no support for conjectured economic advantages over plant based feeds

Study of risk factors and clinicopathological findings associated with urethral obstruction in tom cats in Kerala

Twelve clinical cases of urethral obstruction in tom cats presented to University Veterinary Hospitals of Kerala Veterinary and Animal Sciences University at Kokkalai and Mannuthythat had undergone urinary diversion procedures on the day of presentation were selected for the study. Signalment and anamnesis of the animals were studied to find the risk factors associated with urethral obstruction. The prevalence of urethral obstruction was found to be higher in uncastrated Persian breed of cats,which were one to two years of age. All cats had history of being fed with dry commercial diet, lowered water intake and living indoor. The stress factors identified were inter-cat conflict, fear, relocation, presence of guests and change in owner’s routine. Haematobiochemical profile of these cats revealed significant changes in haematocrit and total erythrocyte count values.Elevated blood urea nitrogen, creatinine, phosphorus and potassium were observed which significantly reduced following bladder evacuation. Urinalysis revealed haematuria, proteinuria,leukocyturia and struvituriaas frequently encountered findings in tom cats with urethral obstruction

Histomorphological stratification of stromal types associated with canine mammary tumours

Cancer associated stroma (CAS) consists mainly of a cellular fraction comprising fibroblasts, myofibroblasts, inflammatory cells, immune cells, endothelial cells, adipocytes and extracellular matrix (ECM). Recent reports have shown that the cancer stroma including the cellular fraction and ECM undergo considerable reprogramming during the process of tumourigenesis. Though there are some studies on CAS of human breast cancers (HBCs), similar studies are very much limited in canine mammary tumours. Hence, the present study was undertaken to classify the stromal types associated with malignant canine mammary tumours(CMTs). The excisional biopsy samples from 50 numbers of CMTs presented to Kerala Veterinary and Animal Sciences University hospitals at Mannuthy and Kokkalai during the period from November 2019 to December 2021 formed the study material. Histopathological stratification of cancer stroma was done using qualitative evaluation based on the stromal characteristics suggested for HBCs. Accordingly the cancer associated stroma in different tumour samples were classified as fibrotic stroma, inflammatory stroma and mixed stroma. Fibrotic stroma was further classified as mature/ sclerotic, intermediate and immature/desmoplastic types. The grade of tumours in relation to the type of stroma was also analysed and it was identified that with the exception of sclerotic stroma, all other stromal types could be observed in higher grades of CMTs. Desmoplastic and inflammatory stroma were predominantly seen associated with Grade II and Grade III tumours