Accelerated Appearance of Skin Tumors in Hairless Mice by Repeated UV Irradiation with Initial Intense Exposure and Characterization of the Tumors

Skin tumors were produced on the back of hairless mice, HOS (HR/De), by exposure to ultraviolet B light (UVB, 290–320 nm) with 4 different protocols. The first tumors appeared earlier (in 10 weeks in group I and 7 weeks in group III) when initial intense exposure was given, followed by repeated lower-level exposures, than when the mice were exposed to the repeated UV only (in 16 weeks both in group II and group IV). All mice developed skin tumors earlier in the groups given the repeated UV exposures three times a week than in the groups given the exposures twice a week. Most of the skin tumors produced by the UVB exposure were histologically malignant, being transplantable to nude mice, and the cultured cells grown from the tumors were capable of producing tumors when injected into nude mice. The accelerated development of skin tumors by initial intense exposure and short intervals of repeated exposure observed in this study may have implications for humans who expose themselves to intense sunbathing and UV tanning (burning) by fluorescent sun lamps.     

Rescue extracorporeal cardiopulmonary resuscitation in pediatric patients: a nine-year single-center experience in Zagreb,Croatia

AimTo investigate the risk factors and the outcomes of extracorporeal membrane oxygenation (ECMO) in pediatric patients treated at the University Hospital Center Zagreb, the largest center in Croatia providing pediatric ECMO.MethodsThis retrospective study enrolled all the pediatric patients who required E-CPR from 2011 to 2019. Demographic data, cardiac anatomy, ECMO indications, ECMO complications, and neurodevelopmental status at hospital discharge were analyzed.ResultsIn the investigated period, E-CPR was used in 16 children, and the overall survival rate was 37.5%. Six patients were in the neonatal age group, 5 in the infant group, and 5 in the “older” group. There was no significant difference between the sexes. Four patients had an out-of-hospital arrest and 12 had an in-hospital arrest. Twelve out of 16 patients experienced renal failure and needed hemodialysis, with 4 out of 6 patients in the survivor group and 8 out of 10 in the non-survivor group. Survivors and non-survivors did not differ in E-CPR duration time, lactate levels before ECMO, time for lactate normalization, and pH levels before and after the start of ECMO.ConclusionThe similarity of our results to those obtained by other studies indicates that the ECMO program in our hospital should be maintained and improved.

The use of extracorporeal cardiopulmonary resuscitation (E-CPR) is increasing (1). E-CPR is defined as an initiation of extracorporeal membrane oxygenation (ECMO) during active chest compressions. Its main goal is to provide immediate cardiovascular support to patients who do not react to CPR (2) and to lead to survival and a better neurological outcome (3). After administering CPR for more than 30 minutes, survival with conventional CPR measures ranges between 0%-5% (4,5).The most recent systematic review by the International Liaison Committee on Resuscitation from 2015 recommended that E-CPR should be considered for children with underlying cardiac conditions who have an in-hospital cardiac arrest when appropriate protocols, expertise, and equipment are available (6). According to the Extracorporeal Life Support Organization (ELSO) registry from 2017 (7), more than 60 000 people received extracorporeal life support (ECLS), between 2009 and 2015, with an overall survival rate of 61% (7). Pediatric ECMO experience in Slovenia shows that ECMO programs may be incorporated in smaller hospitals in the region (8-10). The ELSO database includes data on all reported pediatric ECMO runs, including those conducted with E-CPR, and in patients with congenital heart surgery and neonates with diaphragmatic hernia or meconium aspiration syndrome, etc. During the 6-year period, 3005 E-CPR runs were reported, with an overall survival to hospital discharge of 43% (7). A survival rate of 31% was reported by Ergűn et al (11) and in E-CPR patients with severe burn injury (12). The longer the CPR duration time, the lower was the survival to discharge rate. Matos et al reported an E-CPR survival-to-discharge rate of 33% after >35 min of chest compressions (13). Other studies reported that the overall survival rate of pediatric E-CPR cases was growing, with better neurological outcomes than among the patients in the CPR group only (14). Pilar et al found that in 73 pediatric cardiac patients requiring cardiopulmonary resuscitation for >30 min (15), the survival to hospital discharge was 43.8%, with 3/4 of the patients having normal neurological function or mild neurological disability (15). Based on ELSO registry, approximately 10% of all ECMO patients meet brain death criteria (7). One of the biggest single-center studies, involving 184 pediatric ECPR patients (16), showed a successful ECMO weaning in 63% of the patients and the overall survival rate to hospital discharge of 43%. In the same study, the risk factors linked to increased mortality were presupport pH<7.1, mechanical complications, and neurological complications (16). The E-CPR use can involve many complications, not necessarily linked to factors preceding cardiac arrest, such as low cardiac output syndrome or irreversible respiratory failure (17). Furthermore, common complications of ECMO treatment are fluid overload and acute kidney injury (18). Many studies showed renal replacement therapy (RRT) to be negatively associated with survival (15,16,18,19).This study assessed the risk factors and the outcomes of ECMO in the largest Croatian center providing pediatric E-CPR experience over nine years and compared the survivor and the non-survivor group.     

Genetic markers of male infertility: Y chromosome microdeletions and cystic fibrosis transmembrane conductance gene mutations

Today, approximately 15% of couples have reduced fertility. In most cases the reason is male infertility, usually of genetic origin. Thus, in the context of research in genes involved in reproduction and sex determination, genetic defects in gametogenesis are being extensively studied. The most frequent pathogenic causes of male infertility are Y chromosomal microdeletions and obstructive azoospermia due to congenital absence of the vas deferens (CAVD) in the presence of mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. We have investigated the most common CFTR gene alterations in Croatian men with CAVD, using Roche research prototype assays. Results revealed that the 5T variant was present in 27% of the subjects. The F508 deletion was found in 21% of the subjects. It was the most frequent mutation, although its incidence was much lower than among patients with cystic fibrosis. The prevalence of microdeletions in the azoospermia factor region (AZF) of the Y chromosome in Croatia was 4.5%. This is the first report of Y microdeletions in the Croatian population. Genetic counseling of all couples with the diagnosis of male infertility is recommended before intrauterine insemination, in vitro fertilization, and intracytoplasmic sperm injection, and should also include AZF and CFTR genotyping. Couples requesting assisted reproductive treatment should be offered molecular analysis of the CFTR gene, if male infertility due to obstructive azoospermia is the underlying cause. Also, men with severe oligozoospermia or non-obstructive azoospermia seeking assisted reproductive treatment should be screened for deletions in the Y chromosome.     

Dopamine Response to Psychosocial Stress in Chronic Cannabis Users: A PET Study With [11C]-(+)-PHNO

A number of addictions have been linked with decreased striatal dopamine (DA) receptor availability and DA release. Stress has a key role in cannabis craving, as well as in modulation of dopaminergic signaling. The present study aimed to assess DA release in response to a laboratory stress task with [¹¹C]-(+)-PHNO positron emission tomography in cannabis users (CU). Thirteen healthy CU and 12 healthy volunteers (HV) were scanned during a sensorimotor control task (SMCT) and under a stress condition using the validated Montreal imaging stress task (MIST). The simplified reference tissue model (SRTM) was used to obtain binding potential (BP_ND) in striatal subdivisions: limbic striatum (LST), associative striatum (AST), and sensorimotor striatum (SMST). Stress-induced DA release (indexed as a percentage of reduction in [¹¹C]-(+)-PHNO BP _ND) between CU and HV was tested with analysis of variance. SMCT BP_ND was significantly higher in CU compared with HV in the AST (F=10.38, p=0.003), LST (F=4.95, p=0.036), SMST (F=4.33, p=0.048), and whole striatum (F=9.02, p=0.006). Percentage of displacement (change in BP_ND between SMCT and MIST PET scans) was not significantly different across groups in any brain region, except in the GP (−5.03±14.6 in CU, compared with 6.15±12.1 in HV; F=4.39, p=0.049). Duration of cannabis use was significantly associated with stress-induced [¹¹C]-(+)-PHNO displacement by endogenous DA in the LST (r=0.566, p=0.044), with no effect in any other brain region. In conclusion, despite an increase in striatal BP_ND observed during the control task, chronic cannabis use is not associated with alterations in stress-induced DA release.     

Statin and fibrate treatment of combined hyperlipidemia: the effects on some novel risk factors

The effects of cerivastatin and fenofibrate on proteins involved in haemostasis and on markers of inflammation were investigated in otherwise healthy middle-aged males with combined hyperlipidemia. Besides classical risk factors, other so-called novel risk factors for coronary artery disease are seen to be playing an increasingly important role in the development and progression of atherosclerosis. Thirty-eight males, aged 49 +/-5 years were randomised to 12 weeks treatment either with cerivastatin at a daily dose of 0.2 mg to 0.4 mg to achieve the LDL cholesterol goal of <3.0 mM, or with fenofibrate 250 mg daily. Fasting serum lipids, homocysteine, total and free tissue factor pathway inhibitor (TFPI), plasminogen activator inhibitor (PAI-1) and tissue plasminogen activator (t-PA) antigen and activity, C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) were measured. No change in homocysteine level was observed in the cerivastatin group, while after fenofibrate administration it increased (p <0.0001). Total TFPI decreased significantly after cerivastatin (p = 0.002), but not after fenofibrate. Free TFPI did not decrease after either drug. Neither drug affected (t-PA) antigen and activity, while fenofibrate increased PAI-1 antigen (p <0.05) and activity (p <0.05). Cerivastatin decreased serum CRP values by 49.5% (p = 0.001), and fenofibrate by 29.8% (p = 0.03). The decreases of CRP in the two groups differed significantly (p = 0.04). IL-6 levels decreased significantly in the fenofibrate group (39%; p <0.0001), but not in the cerivastatin group (15%; p = 0.24) No significant decreases were observed for TNF-alpha. Cerivastatin had neutral effects on fibrinolysis, homocysteine or coagulation. On the other hand, fenofibrate increased PAI-1 antigen and activity and homocysteine, and did not affect coagulation. Both cerivastatin and fenofibrate reduced CRP levels, the decrease being significantly greater after cerivastatin. Fenofibrate also significantly decreased IL-6.     

Angioimmunoblastic lymphadenopathy with dysproteinemia following doxycycline administration

Angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) is a primary lymphoproliferative T-cell disorder, currently classified as a peripheral T-cell non-Hodgkin's lymphoma. AILD is characterized by generalized lymphadenopathy, hepatosplenomegaly, immunological abnormalities, polyclonal hypergammaglobulinemia and anemia. We report a case of AILD in an 80-year-old male who presented with a generalized pruritic maculopapular eruption and fever following doxycycline administration. The maculopapular rash progressed to formation of confluent nodules, plaques and finally erythroderma with lymphadenopathy and hepatosplenomegaly. Blood analysis revealed an elevated erythrocyte sedimentation rate and polyclonal hypergammaglobulinemia. Lymph node biopsy showed almost complete effacement of the nodal architecture with diffuse proliferation of small vessels forming an arborizing network, surrounded by atypical lymphocytes, usually CD3+ CD4+ and occasionally CD3+ CD8+. There were also larger cells (immunoblastic shape) that displayed CD20 positively, some scattered plasma cells, and eosinophils. Histology of a cutaneous lesion showed spongiosis and infiltration of the epidermis by atypical lymphocytes with large hyperchromatic nuclei, perivascular dermal lymphocytic infiltrate (CD3+) mixed with plasma cells and occasional large immunoblasts (CD20+). During hospitalization the patient developed hemolytic anemia (Coombs positive) and lung metastases. The prognosis of AILD is generally poor, with a median survival of less than 20 months. Our patient died two and a half months after the diagnosis was made due to sepsis caused by Staphylococcus aureus isolated in hemoculture.     

Hypokalemic metabolic alkalosis--three case reports

The two most common forms of inherited normotensive hypokalemic metabolic alkalosis are Bartter's and Gitelman's syndromes. Bartter's syndrome typically present with normal or increased calcium excretion. Hypomagnesemia occurs in only one third of affected individuals. In contrast, hypomagnesemia and hypocalciuria are considered hallmarks of Gitelman's syndrome. In most patients, the symptom of muscle weakness and polyuria occur early in life, which may be attributed to potassium depletion. Despite hyperaldosteronism, the patients tend to be normotensive, which is at least explained by vascular hyperresponsiveness to prostaglandins. Therapeutic approaches to Bartter's and Gitelman's syndromes include potassium supplementation, prostaglandin synthesis inhibitors (nonsteroid anti-inflammatory agents), aldosterone antagonists and converting enzyme inhibitors. Three patients with hypokalemia, normal blood pressure, metabolic alkalosis, hyperreninemia and hyperaldosteronism are described. Two patients had Bartter's syndrome and one patients had Gitelman's syndrome.