The effect of post-COVID-19 on gustatory and olfactory function: A preliminary case-controlled study

AIMS

The aim of the study was to analyze objective and subjective olfactory/gustatory function in post-COVID-19 infection (PCI).

MATERIALS AND METHODS

Patients with past PCR-confirmed COVID-19 infection and persistent olfactory/gustatory complaints were investigated. Olfactory threshold and identification, gustatory detection, identification, and magnitude scaling were tested.

RESULTS

A total of 42 PCI subjects were compared to 41 age- and gender-matched controls with no COVID-19 history. All PCI tested had mild COVID-19 disease. Mean interval between COVID-19 confirmations to testing was 7.4 ± 3.1 months. PCI subjects complained of combined dysfunction in 85.7%, isolated olfactory or gustatory dysfunction in 7.1% each. Combined complaints were significantly higher in PCI (p < 0.001). Objective testing showed significantly higher prevalence of dysfunction in PCI versus controls for hyposmia (73.8%, 12.2%), anosmia (11.9%, 0%), odor identification (68.5%, 83.0%), hypogeusia (23% and 2.4%, respectively), and impaired magnitude scaling, (p < 0.05). All PCI subjects with hypogeusia had abnormal gustatory magnitude scaling.

CONCLUSIONS

While most PCI subjects complained of combined gustatory and olfactory dysfunction, objective testing showed in the majority an isolated single sense dysfunction, with a low level of agreement between subjective and objective findings. Abnormal objective results for all olfactory and gustatory functions tested may suggest a central rather than peripheral mechanism, although concomitant mechanisms cannot be excluded.

The profile of chronic hyperplastic candidiasis: a clinico-pathological study

The aims of this study were investigation of clinical presentation, systemic factors, and long-term malignant transformation rate in chronic hyperplastic candidiasis versus leukoplakia. This is a retrospective case-controlled study of cases with chronic hyperplastic candidiasis and leukoplakia without dysplasia, diagnosed between 2000 and 2013. A database was created, and all additional biopsies from the same cases were searched up to 2022, for records of oral malignant transformation. Associations between microscopic diagnoses and clinical features of lesions and clinical outcomes of patients were performed. A study database included 116 patients, allocated to the group diagnosed with chronic hyperplastic candidiasis (CHC-group, 62) and to the group of leukoplakia without dysplasia (LKP-group, 54). Tongue and buccal mucosa were most frequently recorded in both groups. In CHC-group, significantly fewer cases presented as white lesions compared to LKP-group (P < 0.001); more were ulcerated or exophytic (P = 0.006 and P = 0.003, respectively). History of head and neck malignancy was significantly more frequent in CHC-group (P = 0.005), as were chemotherapy, (P = 0.019) radiotherapy (P = 0.0265), and immune-related conditions (P = 0.03). Within the follow-up period (2000-2022), in CHC-group, two cases (3.2%) had malignant transformation at the site of original biopsy, one was recurrence of previous carcinoma. In LKP-group, two cases (3.7%) had newly diagnosed carcinoma and one at the site of original biopsy; no significant differences were found between groups. In conclusion, medical background of immune-related conditions, head and neck malignancy, radiotherapy, and chemotherapy may play a role in predisposing for chronic hyperplastic candidiasis. Malignant transformation rate within CHC-group was low, and similar to that within LKP-group, representing a lower transformation rate than expected.

Unexpected Candidal Hyphae in Oral Mucosa Lesions-A Clinico-Pathological Study

Background: Oral mucosal biopsies might harbor candidal hyphae (CH) in the absence of any clinical signs or symptoms. Aim: To assess oral mucosa biopsies for the frequency of unexpected CH and characterize their clinico-pathological features. Materials and Methods: All biopsy reports (2004−2019) were searched using CH/candida/candidiasis as key words. Cases with clinical diagnosis of oral candidiasis (OC) were excluded. Demographic data, health status, smoking habits, clinical features and diagnoses were collected. Statistical analysis included the chi-square test; significance was set at p < 0.05. Results: Of all the biopsies, 100 (1.05%) reported microscopical evidence of CH without typical clinical signs/symptoms of OC. Fifteen cases were from healthy, non-smoking patients. CH was common on buccal mucosa (38%) and lateral tongue (23%). The tip of tongue (OR = 54.5, 95% CI 9.02−329.4, p < 0.001) and lateral tongue (OR = 3.83, 95% CI 2.4−6.09, p < 0.001) were more likely to harbor CH-positive lesions. CH-positive lesions were diagnosed as epithelial hyperplasia (55%) and exophytic reactive lesions (30%). No correlation was found between CH and the grade of epithelial dysplasia. Conclusions: Microscopic evidence of CH embedded into oral epithelium without typical signs/symptoms of OC is rare, especially in healthy, non-smokers. Since CH was occasionally found in oral sites prone to local trauma and in association with reactive lesions, in absence of host co-morbidities, the contribution of local mechanical forces to CH embedment cannot be ruled out.

Peripheral giant cell granuloma associated with dental implants: Case-series

PURPOSE

The objectives were to characterize clinico-pathologically a large series of peri-implant peripheral giant cell granuloma (PGCG), and investigate the role of foreign material as a possible etiological factor.

MATERIAL AND METHODS

The study was retrospective, conducted on peri-implant specimens submitted for histology between 2005 and 2021.

RESULTS

Three hundred and thirty-five peri-implant biopsies were retrieved, of which 52 (15.5%) were PGCG. The study population included 28 females and 24 males, age 35-92 years, mean 61. 51.2% reported bone involvement. The lesion involved the margins of the specimen in 65.3%, recurrence was reported in 46.1%. In 58.8% the implant was removed at the same time the specimen was submitted for histopathological analysis. Small foci of black granular foreign material were observed in 53.8% of cases of which 67.8% were birefringent under polarized light. The foreign material granules were not ingested inside multinucleated giant cells, but were scattered in the stromal compartment.

CONCLUSIONS

Peri-implant PGCG is locally aggressive, with frequent bone involvement and high recurrence rate, resulting in implant loss in the majority of cases. The high recurrence rate may be related to conservative or inadequate surgery. Foreign material although common does not seem to have a role in its development.

Inverse dose- and time-dependent effect of basic fibroblast growth factor on the gene expression of collagen type I and matrix metalloproteinase-1 by periodontal ligament cells in culture

BACKGROUND

Growth factors are known to play a major role in the regeneration of the periodontium. Basic fibroblast growth factor (bFGF) is a polypeptide growth factor considered to have a role in chemotaxis and mitogenesis of periodontal ligament cells (PLC). The aim of this study was to assess the dose-dependent effect of bFGF administration on the levels of gene expression of collagen type I (a1) (col I), collagen type III (col III), and collagenase-1 (MMP-1) in PLC.

METHODS

PLC were cultured in different concentrations of bFGF (0.1 to 10 ng of bFGF) for 14 and 21 days. At each time point, the gene expression of the examined molecules was assessed semi-quantitatively by reverse transcription-polymerase chain reaction (RT-PCR) assay.

RESULTS

The results indicated that bFGF exhibits an inverse time- and dose-dependent effect on the gene expression of col I and MMP-1: it simultaneously downregulates the gene expression of col I and upregulates the gene expression of MMP-1. On the other hand, bFGF had no dose-dependent effect on col III gene expression. The effect of bFGF on the expression of the three genes was modulated by the time of incubation with bFGF.

CONCLUSIONS

These results suggest that bFGF is one of the important regulators involved in the active remodeling of col I in the periodontal ligament and possibly in other connective tissues.

Metabolic and toxicological studies on cobalt

In this study, the following in vitro and in vivo experiments were carried out: (a) Rats were exposed to the radionuclide 57Co2+ ions in single intraperitoneal or intravenous doses (from 10 ng to 1 mg Co/rat) or to 50 ng Co/rat/day through drinking water for 109 days. The target tissue for cobalt depended on the dosage and route of administration (e.g. lung, kidney or bone). Excretion took place mainly through urine (i.p. and i.v. administration) or feces. At 24 h, testis of rats i.v. injected with 10 ng Co/rat contained 0.056% of the dose, with approximately 0.036% in the epididymus, and 0.08% in the deferens. No radioactivity was found in the germinal cells. (b) In vitro incorporation of cobalt in rat sperm. Cobalt enters the germinal cells suggesting that in vivo barriers against the incorporation of the element in sperms may occur. (c) Dose-effect relationships in BALB/3T3 cell cultures exposed to concentrations of cobalt from 1000 to 1 microM of Co2+. Cobalt induced a dose dependent cytotoxic response. At 10 microM, cell growth was reduced to about 30%. No inhibition was found at 1 microM. Morphological transformation assays gave negative results when the cells were exposed to 1000 microM of cobalt.

Cobalt speciation in urine of hard metal workers. A study carried out by nuclear and radioanalytical techniques

A method for the determination of inorganic and organically-bound cobalt in human urine has been developed and applied to the urine of hard metal workers. The development was based on the use of the radionuclides 57Co, 58Co and 60Co-labelled Co compounds such as Co-Vitamin B12 and CO2+ ions which allowed the study of their biotransformations in human and rat urine. The proposed procedure is based on the use of Chelex 100 resin which retains quantitatively the inorganic Co from the urine while the organic complexed form of the element is eluted. Cobalt is detected in both column and eluate by neutron activation analysis (NAA). The method has been applied to speciate inorganic and organically-bound Co in the urine of hard metal workers. There is a significant increase (P < 0.02) of the ratio inorganic/organic Co (2.3) in the urine of workers compared with controls (1.01), showing an increase of the inorganic fraction of Co in the urine of workers. The ratio was constant for the wide range of urinary Co analyzed (from 180 micrograms to 1254 micrograms Co/l). Therefore, the discrimination between inorganic and organic Co in urine should not represent progress in the biological monitoring of Co compared with the determination of total urinary Co. However, a large amount of organically-complexed Co is formed in the body of hard metal workers and excreted in urine, thus, investigations of the nature of the organo-cobalt compounds are of fundamental importance in establishing their possible clinical significance.

Biliary excretion of barium in the rat

Biliary excretion of barium was studied in Sprague-Dawley bile-duct-cannulated rats injected intravenously with 1.8 micrograms Ba/rat as 133Ba-labeled barium chloride. Approximately 0.5% of the barium dose was excreted into bile within 2 h. The time-course profile of biliary excretion of the radiotracer closely reflected that of plasma concentrations. Biliary barium levels reached their peak in the first 15-min period after administration and rapidly declined thereafter. The plasma-to-bile barium-concentration ratio was approx 1 at 2 h after injection. There was no tendency of barium to concentrate in liver, and the 133Ba levels in stomach and small intestine largely exceeded hepatic levels. There is evidence indicating that barium is predominantly excreted with feces following parenteral administration in rats and humans. The results of this study suggest that biliary excretion is of little quantitative importance and that physiological routes other than bile contribute to elimination of barium by the digestive tract.

Vanadium transport across placenta and milk of rats to the fetus and newborn

The transport of vanadium across placenta and milk rats was studied by iv injection of low doses of 48V-labeled pentavanadate (0.1 micrograms V/rat) to pregnant and nursing rats. Significant concentrations of vanadium were found in the liver, intestine, and kidneys of the fetuses, showing that vanadium is capable to pass the placental barrier and, thus, being metabolized in the fetuses. Two days after injection of 0.1 micrograms V/rat as 48V-labeled vanadate to nursing rats, 34 ng V/g milk were found, decreasing to 4 ng V/g at the d 12 after dosing. The corresponding suckling rats showed a significant absorption of vanadium taken up by the milk, as suggested by the presence in their intestine, where 48V is easily absorbed in form of low molecular weight components. Vanadium in milk may be transported in the form of a biocomplex with lactoferrin, since at 12 d after injection, the 48V in the rat milk was mainly found in fractions corresponding to proteins. In weanling rats, 7 d postlactation and 18 d after administration of vanadium to the mother, only very small amounts of 48V were still present in the organs. Excretion studies on weanling rats for 7 d showed that vanadium is rapidly released mainly via feces when earlier taken up by the milk of iv injected mothers and having the same elimination pattern as the milk, which lost about 80% of its vanadium concentration after 12 d.

Blood coagulation studies in guineapigs (Cavia porcellus)

Blood coagulation studies were performed on 45 healthy, adult guinea pigs. Additionally thrombelastograms of 30 animals were recorded. Guineapigs revealed short partial thromboplastin times and euglobulin lysis times, but long prothrombin times and thrombin times. Fibrinogen values were within the range of human normal values. Biphasic ADP-induced aggregation of platelets, as occurs in man, was found in 29% of the animals. Short r (reaction time until the beginning of clot formation) and k times (time from the beginning of clot formation until an amplitude of 20 mm) of their thrombelastograms indicate, that whole blood clotting is enhanced in guineapigs. Higher maximum amplitudes in this species suggest a stronger clot stability than in man.

Retention of intratracheally instilled and ingested tetravalent and pentavalent vanadium in the rat

The retention, subcellular distribution in the liver, kidneys and lungs and binding of vanadium in the rat were investigated at 3 h, 1 d and 12 d after intratracheal instillation of 200 ng/kg body weight of 48V-labelled pentavalent and tetravalent vanadium. The metabolic patterns of both chemical forms of vanadium were similar. The lungs, liver, kidneys, bone, testes and spleen are the target tissues at risk, vanadium being removed from them with time at different rates. Pulmonary vanadium clearance was initially rapid - 80-85% of the 48V was removed within 3 h. At 12 d about 2% of the element was still present in the lung. Intracellularly, the major part of liver, kidney and lung vanadium was present in the nuclear fraction (30-40% of the homogenate), followed by cytosol and mitochondrial fractions. Gel filtration chromatography of the lung cytosol showed two biochemical pools of vanadium: the first corresponding to protein bound vanadium, which may be involved in the long-term accumulation of the element in the lung, the second pool representing a diffusible vanadium form. The retention of the tetravalent and pentavalent vanadium forms was also investigated 1 d after oral administration. No obvious differences were observed in the distribution pattern of 48V in the tissues, the retention factor being higher by two orders of magnitude in comparison with the intratracheally instilled animals. These findings suggest that the metabolic pathways of tetravalent and pentavalent vanadium are independent of the route of vanadium exposure.

Environmental and biochemical trace-metal speciation studies by radiotracers and neutron activation analysis

Although knowledge of the total concentrations of trace metals in the environment and living organisms is still the essential starting point for any toxicological evaluation, it is, however, not sufficient to explain the mechanisms responsible for retention and toxic effect of trace metals. Differentiation between their chemical and biochemical forms is necessary. The need to resolve the total concentration of trace metals into single chemical species poses great experimental difficulties and imposes the use of very sensitive analytical techniques for trace metal determinations after specific preseparation procedures of the different chemical species.Thus, once the chemical or biochemical metal species have been selectively isolated, the speciation becomes merely an analytical problem, which requires high sensitivity and accuracy, as well as the evaluation of matrix effects, blanks, contamination, loss, and sampling.This paper describes the use of nuclear and radiochemical techniques related to chemical and biochemical speciation problems at the Joint Research Centre, Ispra, with carrier-free radiotracers and radiochemical neutron activation analysis.

Pathways of Cr (III) and Cr (VI) in the rat after intratracheal administration

51Cr-labelled Cr3+ and CrO2-4 solutions were administered intratracheally to male rats in doses of 0.1 and 10 micrograms of Cr per rat to evidentiate metabolic differences especially in the lung and in the mechanisms of excretion. Twenty four hours after administration the highest 51Cr amount was present in the lungs for both valency states, being in the Cr (III)-treated group, however, about two times higher. In all other tissues tested the values in the Cr (VI)-treated animals were much higher. Intracellularly, in the Cr (III)-treated group more than 40% of the total lung homogenate was found in the nuclear fraction and only 10% in the cytosol. In the Cr (VI)-treated group 25% was present in the nuclei and more than 50% in the cytosol. Gel filtration 24 h after intratracheal injection showed that in both cytosols chromium was eluted in three peaks including a low-molecular-weight component. Quantitatively, however, the ratios between the 51Cr associated with the three peaks were significantly different between the Cr (III)- and the Cr (VI)-treated animals. This suggests that binding of chromium to low-molecular-weight components should be involved in the passage of this element from the lung to the other tissues. Excretion studies for 7 days showed that after this time the Cr (III)-treated animals excreted about 4% of the dose via urine and more than 36% via faeces, whereas in the Cr (VI)-treated rats the 51Cr was eliminated nearly equally between urine and faeces.

Retention and tissue binding of titanium in the rat

The fate of a soluble form of titanium (Ti) was studied in rats injected intraperitoneally with 1 microgram of Ti per rat as [44Ti]ammonium oxalotitanate (IV). After 16 h the Ti concentration in all tissues tested was of the order of 0.5 ng/g wet weight. After 19 days the Ti concentration increased in most tissues, especially in spleen, femur and kidney. By this time 55 ng had been excreted both via urine and faeces and the Ti concentration in blood plasma (mainly associated with plasma proteins) was three times lower than at 16 h postinjection. Chromatographic separation of the day 19 liver cytosol showed the ability of biological macromolecules to incorporate Ti compounds. Ti-labelled 'titanic acid' and 'titanium phosphate' showed low solubility which was, however, higher in human serum than in water and sodium chloride solution. The chromatographic profiles of plasma from incubated human blood in vitro with [44Ti]titanium oxalate showed the capacity of plasma proteins to complex Ti compounds. The results indicated that the long retention of Ti in the body may be due to its ability to form biocomplexes with cellular constituents.

Intestinal absorption and excretion of thallium (201Tl) in the rat

The gastrointestinal transport of 201Tl-labelled monovalent thallium has been studied in normal and rats with cannulated bile ducts using an in vivo ligated loop technique. A marked difference in the Tl absorptive capacity among the various sections of the gut was observed. 201Tl was taken up more quickly from the colon than from any other segment and the uptake from the ileum and jejunum was higher than from the stomach. In addition, considerable amounts of the intravenously administered thallium were excreted into the intestinal lumen. The biliary excretion was very low compared with the direct transfer of 201Tl across the gastrointestinal wall that occurred against a tissue-to-plasma concentration gradient. In the rat, the large intestine seems to be the major area for the enteral reabsorption and recycling of thallium (I) ions.

Biliary and gastrointestinal excretion of chromium after administration of Cr-III and Cr-VI in rats

Rats treated intravenously with 51Cr-labelled sodium chromate, 0.1 or 100 microgram Cr/rat, excreted more 51Cr into bile in a 2-hr period than did the animals given equal amounts of chromium in the trivalent state. Distinct patterns of hepatic intracellular distribution of the radiotracer were also observed. In the Cr-VI rats over 50% of the liver chromium was present in the supernatant fraction whereas in the Cr-III rats almost all the liver radioactivity was localized in the cell organelles. Fractionation of bile on Sephadex G-75 demonstrated binding of chromium to low-molecular weight substances. It is suggested that complexes of chromium with low-molecular weight components of liver cytosol are involved in the passage of this element from the liver to bile. A low cytosolic content of diffusable Cr-complexes associated with the incorporation of a large fraction of liver chromium in cell organelles may be a factor contributing to the low rates of 51Cr biliary excretion in the animals given Cr-III. 24 hr after the injection of 51Cr to bile duct-ligated rats appreciable levels of radiotracer were found in the gastrointestinal tract. The animals given Cr-VI exhibited significantly higher values of chromium content in the gut than those treated with Cr-III.

Intracellular interaction and biotransformation of arsenite in rats and rabbits

The accumulation of arsenic with time in tissues of rats and rabbits was determined by neutron activation analysis (NAA). Rats showed a steady increase in the As-concentrations with age, whereas in rabbits it was nearly the same for adults and in young animals. The metabolism of arsenic was studied in both animal species after i.p. injection of 50/micrograms As/kg b.w. as 74As labelled arsenite. Eight tissues, as well as blood and urine, were analysed for 74As content after 16 and 48 hours. The binding of 74As to hematic and intracellular components and the chemical forms of arsenic in tissues and urine were investigated. In the plasma and the RBC-fraction of the rabbit, the As concentration decreased during the first two days, while in the rats it only disappeared from the plasma, but was retained in the RBC-fraction. Liver, kidney and lung of rabbits with the highest As concentrations at 16 and 48 hours showed a rapid clearance of As in the first 48 hours. In the corresponding tissues of the rats, the rate of decline was significantly lower, due to the higher binding of 74As to tissue constituents. Poor binding of As to plasma proteins was seen in rabbits while in rats it was totally bound to this fraction. In the RBC, liver and kidney cytosols, however, the affinity of As for intracellular proteins was higher in both animal species but characterized by a rate of binding different between the two animal species. The amount of dimethylarsinic acid (DMA) in the tissues was significantly lower in the rat than in the rabbit, reflecting the total amount of diffusible arsenic, which was also much lower in the tissues of rats than in rabbits.

Additional factor XII (Hageman factor) deficiency in hemophilia A and in von Willebrand syndrome

Factor XII plasma levels were investigated with several methods in patients with hemophilia A and B and von Willebrand syndrome. There seem to be some families with hemophilia A or von Willebrand syndrome, who have an additional, congenital, partial lack of factor XII (Hageman factor). The mode of inheritance is independent of the other coagulation disorder. Frequently, the first indication of an additional factor XII deficiency is the disproportionate prolongation of the activated partial thromboplastin time (PTT) as regards the factor VIII level. The average factor XII level in patients with hemophilia A and von Willebrand syndrome is significantly lower than in normal subjects or patients with hemophilia B. It cannot be excluded that the frequently low levels of factor XII in patients with severe hemophilia are acquired and probably due to liver cell damage.

Organ/tissue disposition of thallium in pregnant rats

The placental transfer of thallium was studied in rats treated with a toxic dose of thallium sulphate (10 mg Tl/kg b.wt. p.o.), as well as in animals injected intraperitoneally with 201Tl-labelled thallium in amounts as low as 2 micrograms Tl/rat. Rapid uptake and retention of thallium in both maternal and fetal organs were observed. The administration of potassium ferrihexacyanoferrate II (100 mg/kg b.wt. twice daily by gavage) to rats acutely intoxicated with thallium on day 17 of pregnancy resulted in significant decrease of thallium concentrations in various maternal tissues including brain, in the placenta as well as in the fetal liver and brain. Potassium ferrihexacyanoferrate II also reduced the mortality of pregnant animals in the 72-h interval after the intoxication.