A suggested protocol to increase the accuracy of prosthetic phases in case of full-arch model-free fully guided computer-aided implant placement and immediate loading.

PURPOSE: The accuracy of fully digital model-free surgical and prosthetic procedures depends on the cumulative effect and interaction of all errors gathered along the entire workflow process. In the present case series, a technique is described that increases the accuracy in the transition from the surgical to the prosthetic phase to reduce the risk of developing prosthetic complications in the case of immediate loading protocols. METHODS: Overall, 86 dental implants were placed and immediately loaded with definitive prostheses in 11 edentulous patients following computer-guided implant surgery according to a fully digital model-free workflow. The same reference template used to anchor the surgical stent during computer-aided implant placement was used to guide the insertion of the definitive abutments and to seat in the correct position the final screw-retained implant-supported fixed restoration. The template used during all surgical and prosthetic procedures, which served as a stable and reproducible connection between the digital and surgical environments, was finally removed. RESULTS: Healing proceeded uneventfully in all subjects. The implant survival and success rates were 100% over a minimum follow-up period of 1 year from the prosthetic loading. No biological or prosthetic complications were clinically and radiographically observed up to the last follow-up recall. CONCLUSION: The use of a reference template used to transfer the digital project to the surgical field increased the accuracy and the integration of the surgical and prosthetic phases during the entire workflow.

Utilization of phytohaemagglutinin for in vivo karyological studies in teleost fish.

A simple technique is described for increasing the number of mitoses in circulating blood and in the kidney of teleost fish. This method employed phytohaemagglutinin-P solution, a T-like cell mitogen, which was injected (1 mg/100 g body wt) intraperitoneally, and 53 h later many blasts suitable for karyological studies, blocked in metaphase, were present both in the circulating blood and in the kidney.

[Utilization of CoCl2 for karyological studies in teleosts]. / Utilizzazione del CoCl2 per studi cariologici nei Teleostei.

This paper presents a simple method of increasing the number of mitoses in the kidney of fish. This method is based on the erythropoietic activity of CoCl2. The specimens of Ictalurus sp. were injected intraperitoneally with 2 mg CoCl2 per 100 g body weight. After 24 h the slides of kidney show a proliferation of erythroblasts. A large number of these cells are arrested in metaphase for karyotype preparations.

[Effect of DDT on hepatocytes in Ictalurus sp. and Carassius carassius]. / Azione del DDT sugli epatociti di Ictalurus sp. e Carassius carassius.

During fifteen days low dosages of DDT on two different LC50-teleost fishes (Ictalarus sp. and Carassius carassius) were studied. Treatment with DDT, after three days, induces in Carassius hepatocytes a loss of glycogen granules, an increase of ergastoplasm, a mitochondrial swelling and wide cytoplasmic vacuoles. In Ictalurus there is no glycogen loss, but an increase of ergastoplasm and a great increase of lipidic inclusions are observed.

Glucagon control of glycogenolysis in catfish tissues.

1. In catfish (Ictalurus melas) after glucagon treatment blood glucose increased until 150 min, then it gradually decreased towards control values at the 5th hr. 2. In glucagon treated fish, liver glycogen levels were significantly lower then in controls 30 min after hormone administration; thereafter, liver glycogen levels returned rapidly to initial values. Glucagon did not induce any significant effect on the glycogen content in white and red muscles. 3. In liver slices, the addition of glucagon to the incubation medium significantly enhanced the glycogen phosphorylase activity and decreased the level of glycogen. Both phosphorylase activity and glycogen content of white and red muscle slices were practically unaffected by glucagon.

Epinephrine effects on carbohydrate metabolism in catfish, Ictalurus melas.

Epinephrine injection in catfish, Ictalurus melas, induced (a) a rapid hyperglycemia which lasted for more than 5 hr; and (b) a slight immediate decrease of glycogen in liver and muscles (red and white), followed by an increase at 48th hr in the liver. Epinephrine, added in vitro to tissue slices, increased the output of glucose from liver and enhanced the decrease of glycogen seen in controls. Among the other organs, only white muscle showed a greater decrease of glycogen than the controls. These effects are attributed to an increase of glycogen phosphorylase activity induced by the hormone.

Effect of insulin on glycogen metabolism in isolated catfish hepatocytes.

Insulin effect on carbohydrate metabolism in catfish hepatocytes consisted of a significant decrease of cell glycogen concentration both in the absence and in the presence of glucose in the medium. The hormone did not influence either the output of glucose from the cell or the intracellular glucose level. Experiments with radioactive glucose showed a very low uptake of the sugar by the hepatocytes; correspondingly the incorporation of radioactivity into glycogen was very low and not influenced by insulin. The glycogen content in catfish liver cells was influenced by the hormone in the opposite way to rat liver cells.

[Effect of adrenaline on blood glucose and glycogen in catfish tissues]. / Effetto dell'adrenalina sulla glicemia e sul glicogeno nei tessuti di pesce gatto.

The effects of epinephrine injected intraperitoneally (5 mg/kg body weight) on the catfish carbohydrate metabolism were studied. Epinephrine caused a very high and persisting hyperglycemia, the highest value of which was 340 +/- 21 mg/100 ml of blood (control value: 75 +/- 6 mg/100 ml) at 24th hour after the administration. Moreover, epinephrine caused glycogenolysis in liver: from 127 +/- 10 to 95 +/- 8 mg/g of tissue. In white muscle the lowering of glycogen happened just after the epinephrine injection and reached the lowest value (1,6 +/- 0,3 mg/g) at 2,5 hours after the administration (control value: 2,9 +/- 0,4 mg/g). A glycogen decrease took place in red muscle with a great delay, but was still present 48 hours after administration (control value: 17,5 +/- 1,8 mg/g; sample value: 11,2 +/- 3,2 mg/g). The increase of glucose level in blood could be referred to glycogenolytic processes in liver. As far as musculature is concerned, red muscle probably plays a role in recovering the glycogen level in white muscle.

"In vivo" effects of insulin on carbohydrate metabolism of catfish (Ictalurus melas).

The effect of insulin was studied on blood glucose, and on the glycogen level of liver, muscles and heart in fed and in starved catfish (Ictalurus melas). Fish received intraperitoneally 60 iu/kg body weight of bovine insulin, or physiological saline and were sacrificed after 2, 4, 8, 24, 72 hr from injection. Insulin caused a decrease of blood glucose level, both in fed and in fasted animals, and the effect is more evident in fed animals. After insulin treatment, liver glycogen shows a decrease which is significant at the 8th and 24th hr in fasted and in fed animals respectively; after 72 hr the glycogen level in livers of fed and fasted animals is still very low. Insulin increases the glycogen level both in white and in dark muscle, both in fed and in fasted fish, although with different characteristics, but at the 72nd hr in all animals, the increases are significant. Hormone treatment does not change heart glycogen levels in fed catfish till the 24th hr, then there is a net decrease; in starved animals the decrease begins at the 2nd hr, but only at the 48th hr is it significant. The role of insulin was discussed in relation to the lowering of glycogen concentration in liver, in connection with the fact that many authors found different and even opposite effects of this hormone in various fish. It is possible that the glycogen depletion observed in liver after insulin injection is not due to a direct action of this hormone, but depends on the stimulated production of other specific glycogenolytic hormones, such as epinephrine and/or glucagon.

[Effect of insulin on carbohydrate metabolism in the catfish (Ictalurus melas). I) In vivo experiments]. / Effetto dell'insulina sul metabolismo glucidico del pesce gatto (Ictalurus melas). - I) Esperimenti "in vivo".

The effects of bovine insulin on blood glucose, liver and muscle glycogen were studied in catfish (Ictalurus melas). 60U/k body weight of bovine insulin injected intraperitoneally, produced a significant lowering of blood glucose and liver glycogen, more evident 48 h after injection. An increase after hormone injection was also observed into white muscle glycogen.

[Effect of insulin on carbohydrate metabolism in the catfish (Ictalurus melas). II) In vitro experiments]. / Effetto dell'insulina sul metabolismo glucidico del pesce gatto (Ictalurus melas). - II) Esperimenti "in vitro".

Isolated hepatocyte preparations were used to study the "in vitro" effects of insulin on catfish (Ictalurus melas) carbohydrate metabolism. Insulin decreases spontaneous glycogen lowering either in absence or in presence of glucose in the medium. In the same time insulin produces a little increase on the cell glucose level, but reduces the cell uptake of glucose from medium. The effect of insulin shows to be less evident on isolated hepatocytes than in the intact animals.